fd56b7ec88b656e645a2af4551be76873d746531
[linux-3.10.git] / drivers / scsi / sg.c
1 /*
2  *  History:
3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
4  *           to allow user process control of SCSI devices.
5  *  Development Sponsored by Killy Corp. NY NY
6  *
7  * Original driver (sg.c):
8  *        Copyright (C) 1992 Lawrence Foard
9  * Version 2 and 3 extensions to driver:
10  *        Copyright (C) 1998 - 2005 Douglas Gilbert
11  *
12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2, or (at your option)
17  * any later version.
18  *
19  */
20
21 static int sg_version_num = 30533;      /* 2 digits for each component */
22 #define SG_VERSION_STR "3.5.33"
23
24 /*
25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
28  *        (otherwise the macros compile to empty statements).
29  *
30  */
31 #include <linux/config.h>
32 #include <linux/module.h>
33
34 #include <linux/fs.h>
35 #include <linux/kernel.h>
36 #include <linux/sched.h>
37 #include <linux/string.h>
38 #include <linux/mm.h>
39 #include <linux/errno.h>
40 #include <linux/mtio.h>
41 #include <linux/ioctl.h>
42 #include <linux/fcntl.h>
43 #include <linux/init.h>
44 #include <linux/poll.h>
45 #include <linux/smp_lock.h>
46 #include <linux/moduleparam.h>
47 #include <linux/devfs_fs_kernel.h>
48 #include <linux/cdev.h>
49 #include <linux/seq_file.h>
50 #include <linux/blkdev.h>
51 #include <linux/delay.h>
52
53 #include "scsi.h"
54 #include <scsi/scsi_dbg.h>
55 #include <scsi/scsi_host.h>
56 #include <scsi/scsi_driver.h>
57 #include <scsi/scsi_ioctl.h>
58 #include <scsi/sg.h>
59
60 #include "scsi_logging.h"
61
62 #ifdef CONFIG_SCSI_PROC_FS
63 #include <linux/proc_fs.h>
64 static char *sg_version_date = "20050908";
65
66 static int sg_proc_init(void);
67 static void sg_proc_cleanup(void);
68 #endif
69
70 #ifndef LINUX_VERSION_CODE
71 #include <linux/version.h>
72 #endif                          /* LINUX_VERSION_CODE */
73
74 #define SG_ALLOW_DIO_DEF 0
75 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
76
77 #define SG_MAX_DEVS 32768
78
79 /*
80  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
81  * Then when using 32 bit integers x * m may overflow during the calculation.
82  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
83  * calculates the same, but prevents the overflow when both m and d
84  * are "small" numbers (like HZ and USER_HZ).
85  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
86  * in 32 bits.
87  */
88 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
89
90 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
91
92 int sg_big_buff = SG_DEF_RESERVED_SIZE;
93 /* N.B. This variable is readable and writeable via
94    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
95    of this size (or less if there is not enough memory) will be reserved
96    for use by this file descriptor. [Deprecated usage: this variable is also
97    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
98    the kernel (i.e. it is not a module).] */
99 static int def_reserved_size = -1;      /* picks up init parameter */
100 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
101
102 #define SG_SECTOR_SZ 512
103 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
104
105 #define SG_DEV_ARR_LUMP 32      /* amount to over allocate sg_dev_arr by */
106
107 static int sg_add(struct class_device *);
108 static void sg_remove(struct class_device *);
109
110 static Scsi_Request *dummy_cmdp;        /* only used for sizeof */
111
112 static DEFINE_RWLOCK(sg_dev_arr_lock);  /* Also used to lock
113                                                            file descriptor list for device */
114
115 static struct class_interface sg_interface = {
116         .add            = sg_add,
117         .remove         = sg_remove,
118 };
119
120 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
121         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
122         unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
123         unsigned bufflen;       /* Size of (aggregate) data buffer */
124         unsigned b_malloc_len;  /* actual len malloc'ed in buffer */
125         void *buffer;           /* Data buffer or scatter list (k_use_sg>0) */
126         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
127         unsigned char cmd_opcode; /* first byte of command */
128 } Sg_scatter_hold;
129
130 struct sg_device;               /* forward declarations */
131 struct sg_fd;
132
133 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
134         Scsi_Request *my_cmdp;  /* != 0  when request with lower levels */
135         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
136         struct sg_fd *parentfp; /* NULL -> not in use */
137         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
138         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
139         unsigned char sense_b[sizeof (dummy_cmdp->sr_sense_buffer)];
140         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
141         char orphan;            /* 1 -> drop on sight, 0 -> normal */
142         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
143         volatile char done;     /* 0->before bh, 1->before read, 2->read */
144 } Sg_request;
145
146 typedef struct sg_fd {          /* holds the state of a file descriptor */
147         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
148         struct sg_device *parentdp;     /* owning device */
149         wait_queue_head_t read_wait;    /* queue read until command done */
150         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
151         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
152         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
153         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
154         unsigned save_scat_len; /* original length of trunc. scat. element */
155         Sg_request *headrp;     /* head of request slist, NULL->empty */
156         struct fasync_struct *async_qp; /* used by asynchronous notification */
157         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
158         char low_dma;           /* as in parent but possibly overridden to 1 */
159         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
160         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
161         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
162         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
163         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
164         char mmap_called;       /* 0 -> mmap() never called on this fd */
165 } Sg_fd;
166
167 typedef struct sg_device { /* holds the state of each scsi generic device */
168         struct scsi_device *device;
169         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
170         int sg_tablesize;       /* adapter's max scatter-gather table size */
171         Sg_fd *headfp;          /* first open fd belonging to this device */
172         volatile char detached; /* 0->attached, 1->detached pending removal */
173         volatile char exclude;  /* opened for exclusive access */
174         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
175         struct gendisk *disk;
176         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
177 } Sg_device;
178
179 static int sg_fasync(int fd, struct file *filp, int mode);
180 static void sg_cmd_done(Scsi_Cmnd * SCpnt);     /* tasklet or soft irq callback */
181 static int sg_start_req(Sg_request * srp);
182 static void sg_finish_rem_req(Sg_request * srp);
183 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
184 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
185                          int tablesize);
186 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
187                            Sg_request * srp);
188 static ssize_t sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
189                             int blocking, int read_only, Sg_request ** o_srp);
190 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
191                            unsigned char *cmnd, int timeout, int blocking);
192 static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
193                       int wr_xf, int *countp, unsigned char __user **up);
194 static int sg_write_xfer(Sg_request * srp);
195 static int sg_read_xfer(Sg_request * srp);
196 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
197 static void sg_remove_scat(Sg_scatter_hold * schp);
198 static void sg_build_reserve(Sg_fd * sfp, int req_size);
199 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
200 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
201 static char *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
202 static void sg_page_free(char *buff, int size);
203 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
204 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
205 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
206 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
207 static Sg_request *sg_add_request(Sg_fd * sfp);
208 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
209 static int sg_res_in_use(Sg_fd * sfp);
210 static int sg_allow_access(unsigned char opcode, char dev_type);
211 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
212 static Sg_device *sg_get_dev(int dev);
213 static inline unsigned char *sg_scatg2virt(const struct scatterlist *sclp);
214 #ifdef CONFIG_SCSI_PROC_FS
215 static int sg_last_dev(void);
216 #endif
217
218 static Sg_device **sg_dev_arr = NULL;
219 static int sg_dev_max;
220 static int sg_nr_dev;
221
222 #define SZ_SG_HEADER sizeof(struct sg_header)
223 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
224 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
225 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
226
227 static int
228 sg_open(struct inode *inode, struct file *filp)
229 {
230         int dev = iminor(inode);
231         int flags = filp->f_flags;
232         Sg_device *sdp;
233         Sg_fd *sfp;
234         int res;
235         int retval;
236
237         nonseekable_open(inode, filp);
238         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
239         sdp = sg_get_dev(dev);
240         if ((!sdp) || (!sdp->device))
241                 return -ENXIO;
242         if (sdp->detached)
243                 return -ENODEV;
244
245         /* This driver's module count bumped by fops_get in <linux/fs.h> */
246         /* Prevent the device driver from vanishing while we sleep */
247         retval = scsi_device_get(sdp->device);
248         if (retval)
249                 return retval;
250
251         if (!((flags & O_NONBLOCK) ||
252               scsi_block_when_processing_errors(sdp->device))) {
253                 retval = -ENXIO;
254                 /* we are in error recovery for this device */
255                 goto error_out;
256         }
257
258         if (flags & O_EXCL) {
259                 if (O_RDONLY == (flags & O_ACCMODE)) {
260                         retval = -EPERM; /* Can't lock it with read only access */
261                         goto error_out;
262                 }
263                 if (sdp->headfp && (flags & O_NONBLOCK)) {
264                         retval = -EBUSY;
265                         goto error_out;
266                 }
267                 res = 0;
268                 __wait_event_interruptible(sdp->o_excl_wait,
269                         ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
270                 if (res) {
271                         retval = res;   /* -ERESTARTSYS because signal hit process */
272                         goto error_out;
273                 }
274         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
275                 if (flags & O_NONBLOCK) {
276                         retval = -EBUSY;
277                         goto error_out;
278                 }
279                 res = 0;
280                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
281                                            res);
282                 if (res) {
283                         retval = res;   /* -ERESTARTSYS because signal hit process */
284                         goto error_out;
285                 }
286         }
287         if (sdp->detached) {
288                 retval = -ENODEV;
289                 goto error_out;
290         }
291         if (!sdp->headfp) {     /* no existing opens on this device */
292                 sdp->sgdebug = 0;
293                 sdp->sg_tablesize = sdp->device->host->sg_tablesize;
294         }
295         if ((sfp = sg_add_sfp(sdp, dev)))
296                 filp->private_data = sfp;
297         else {
298                 if (flags & O_EXCL)
299                         sdp->exclude = 0;       /* undo if error */
300                 retval = -ENOMEM;
301                 goto error_out;
302         }
303         return 0;
304
305       error_out:
306         scsi_device_put(sdp->device);
307         return retval;
308 }
309
310 /* Following function was formerly called 'sg_close' */
311 static int
312 sg_release(struct inode *inode, struct file *filp)
313 {
314         Sg_device *sdp;
315         Sg_fd *sfp;
316
317         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
318                 return -ENXIO;
319         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
320         sg_fasync(-1, filp, 0); /* remove filp from async notification list */
321         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
322                 if (!sdp->detached) {
323                         scsi_device_put(sdp->device);
324                 }
325                 sdp->exclude = 0;
326                 wake_up_interruptible(&sdp->o_excl_wait);
327         }
328         return 0;
329 }
330
331 static ssize_t
332 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
333 {
334         Sg_device *sdp;
335         Sg_fd *sfp;
336         Sg_request *srp;
337         int req_pack_id = -1;
338         sg_io_hdr_t *hp;
339         struct sg_header *old_hdr = NULL;
340         int retval = 0;
341
342         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
343                 return -ENXIO;
344         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
345                                    sdp->disk->disk_name, (int) count));
346         if (!access_ok(VERIFY_WRITE, buf, count))
347                 return -EFAULT;
348         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
349                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
350                 if (!old_hdr)
351                         return -ENOMEM;
352                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
353                         retval = -EFAULT;
354                         goto free_old_hdr;
355                 }
356                 if (old_hdr->reply_len < 0) {
357                         if (count >= SZ_SG_IO_HDR) {
358                                 sg_io_hdr_t *new_hdr;
359                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
360                                 if (!new_hdr) {
361                                         retval = -ENOMEM;
362                                         goto free_old_hdr;
363                                 }
364                                 retval =__copy_from_user
365                                     (new_hdr, buf, SZ_SG_IO_HDR);
366                                 req_pack_id = new_hdr->pack_id;
367                                 kfree(new_hdr);
368                                 if (retval) {
369                                         retval = -EFAULT;
370                                         goto free_old_hdr;
371                                 }
372                         }
373                 } else
374                         req_pack_id = old_hdr->pack_id;
375         }
376         srp = sg_get_rq_mark(sfp, req_pack_id);
377         if (!srp) {             /* now wait on packet to arrive */
378                 if (sdp->detached) {
379                         retval = -ENODEV;
380                         goto free_old_hdr;
381                 }
382                 if (filp->f_flags & O_NONBLOCK) {
383                         retval = -EAGAIN;
384                         goto free_old_hdr;
385                 }
386                 while (1) {
387                         retval = 0; /* following macro beats race condition */
388                         __wait_event_interruptible(sfp->read_wait,
389                                 (sdp->detached ||
390                                 (srp = sg_get_rq_mark(sfp, req_pack_id))), 
391                                 retval);
392                         if (sdp->detached) {
393                                 retval = -ENODEV;
394                                 goto free_old_hdr;
395                         }
396                         if (0 == retval)
397                                 break;
398
399                         /* -ERESTARTSYS as signal hit process */
400                         goto free_old_hdr;
401                 }
402         }
403         if (srp->header.interface_id != '\0') {
404                 retval = sg_new_read(sfp, buf, count, srp);
405                 goto free_old_hdr;
406         }
407
408         hp = &srp->header;
409         if (old_hdr == NULL) {
410                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
411                 if (! old_hdr) {
412                         retval = -ENOMEM;
413                         goto free_old_hdr;
414                 }
415         }
416         memset(old_hdr, 0, SZ_SG_HEADER);
417         old_hdr->reply_len = (int) hp->timeout;
418         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
419         old_hdr->pack_id = hp->pack_id;
420         old_hdr->twelve_byte =
421             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
422         old_hdr->target_status = hp->masked_status;
423         old_hdr->host_status = hp->host_status;
424         old_hdr->driver_status = hp->driver_status;
425         if ((CHECK_CONDITION & hp->masked_status) ||
426             (DRIVER_SENSE & hp->driver_status))
427                 memcpy(old_hdr->sense_buffer, srp->sense_b,
428                        sizeof (old_hdr->sense_buffer));
429         switch (hp->host_status) {
430         /* This setup of 'result' is for backward compatibility and is best
431            ignored by the user who should use target, host + driver status */
432         case DID_OK:
433         case DID_PASSTHROUGH:
434         case DID_SOFT_ERROR:
435                 old_hdr->result = 0;
436                 break;
437         case DID_NO_CONNECT:
438         case DID_BUS_BUSY:
439         case DID_TIME_OUT:
440                 old_hdr->result = EBUSY;
441                 break;
442         case DID_BAD_TARGET:
443         case DID_ABORT:
444         case DID_PARITY:
445         case DID_RESET:
446         case DID_BAD_INTR:
447                 old_hdr->result = EIO;
448                 break;
449         case DID_ERROR:
450                 old_hdr->result = (srp->sense_b[0] == 0 && 
451                                   hp->masked_status == GOOD) ? 0 : EIO;
452                 break;
453         default:
454                 old_hdr->result = EIO;
455                 break;
456         }
457
458         /* Now copy the result back to the user buffer.  */
459         if (count >= SZ_SG_HEADER) {
460                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
461                         retval = -EFAULT;
462                         goto free_old_hdr;
463                 }
464                 buf += SZ_SG_HEADER;
465                 if (count > old_hdr->reply_len)
466                         count = old_hdr->reply_len;
467                 if (count > SZ_SG_HEADER) {
468                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
469                                 retval = -EFAULT;
470                                 goto free_old_hdr;
471                         }
472                 }
473         } else
474                 count = (old_hdr->result == 0) ? 0 : -EIO;
475         sg_finish_rem_req(srp);
476         retval = count;
477 free_old_hdr:
478         if (old_hdr)
479                 kfree(old_hdr);
480         return retval;
481 }
482
483 static ssize_t
484 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
485 {
486         sg_io_hdr_t *hp = &srp->header;
487         int err = 0;
488         int len;
489
490         if (count < SZ_SG_IO_HDR) {
491                 err = -EINVAL;
492                 goto err_out;
493         }
494         hp->sb_len_wr = 0;
495         if ((hp->mx_sb_len > 0) && hp->sbp) {
496                 if ((CHECK_CONDITION & hp->masked_status) ||
497                     (DRIVER_SENSE & hp->driver_status)) {
498                         int sb_len = sizeof (dummy_cmdp->sr_sense_buffer);
499                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
500                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
501                         len = (len > sb_len) ? sb_len : len;
502                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
503                                 err = -EFAULT;
504                                 goto err_out;
505                         }
506                         hp->sb_len_wr = len;
507                 }
508         }
509         if (hp->masked_status || hp->host_status || hp->driver_status)
510                 hp->info |= SG_INFO_CHECK;
511         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
512                 err = -EFAULT;
513                 goto err_out;
514         }
515         err = sg_read_xfer(srp);
516       err_out:
517         sg_finish_rem_req(srp);
518         return (0 == err) ? count : err;
519 }
520
521 static ssize_t
522 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
523 {
524         int mxsize, cmd_size, k;
525         int input_size, blocking;
526         unsigned char opcode;
527         Sg_device *sdp;
528         Sg_fd *sfp;
529         Sg_request *srp;
530         struct sg_header old_hdr;
531         sg_io_hdr_t *hp;
532         unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
533
534         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
535                 return -ENXIO;
536         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
537                                    sdp->disk->disk_name, (int) count));
538         if (sdp->detached)
539                 return -ENODEV;
540         if (!((filp->f_flags & O_NONBLOCK) ||
541               scsi_block_when_processing_errors(sdp->device)))
542                 return -ENXIO;
543
544         if (!access_ok(VERIFY_READ, buf, count))
545                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
546         if (count < SZ_SG_HEADER)
547                 return -EIO;
548         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
549                 return -EFAULT;
550         blocking = !(filp->f_flags & O_NONBLOCK);
551         if (old_hdr.reply_len < 0)
552                 return sg_new_write(sfp, buf, count, blocking, 0, NULL);
553         if (count < (SZ_SG_HEADER + 6))
554                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
555
556         if (!(srp = sg_add_request(sfp))) {
557                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
558                 return -EDOM;
559         }
560         buf += SZ_SG_HEADER;
561         __get_user(opcode, buf);
562         if (sfp->next_cmd_len > 0) {
563                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
564                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
565                         sfp->next_cmd_len = 0;
566                         sg_remove_request(sfp, srp);
567                         return -EIO;
568                 }
569                 cmd_size = sfp->next_cmd_len;
570                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
571         } else {
572                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
573                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
574                         cmd_size = 12;
575         }
576         SCSI_LOG_TIMEOUT(4, printk(
577                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
578 /* Determine buffer size.  */
579         input_size = count - cmd_size;
580         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
581         mxsize -= SZ_SG_HEADER;
582         input_size -= SZ_SG_HEADER;
583         if (input_size < 0) {
584                 sg_remove_request(sfp, srp);
585                 return -EIO;    /* User did not pass enough bytes for this command. */
586         }
587         hp = &srp->header;
588         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
589         hp->cmd_len = (unsigned char) cmd_size;
590         hp->iovec_count = 0;
591         hp->mx_sb_len = 0;
592         if (input_size > 0)
593                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
594                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
595         else
596                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
597         hp->dxfer_len = mxsize;
598         hp->dxferp = (char __user *)buf + cmd_size;
599         hp->sbp = NULL;
600         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
601         hp->flags = input_size; /* structure abuse ... */
602         hp->pack_id = old_hdr.pack_id;
603         hp->usr_ptr = NULL;
604         if (__copy_from_user(cmnd, buf, cmd_size))
605                 return -EFAULT;
606         /*
607          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
608          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
609          * is a non-zero input_size, so emit a warning.
610          */
611         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
612                 if (printk_ratelimit())
613                         printk(KERN_WARNING
614                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
615                                "guessing data in;\n" KERN_WARNING "   "
616                                "program %s not setting count and/or reply_len properly\n",
617                                old_hdr.reply_len - (int)SZ_SG_HEADER,
618                                input_size, (unsigned int) cmnd[0],
619                                current->comm);
620         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
621         return (k < 0) ? k : count;
622 }
623
624 static ssize_t
625 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
626              int blocking, int read_only, Sg_request ** o_srp)
627 {
628         int k;
629         Sg_request *srp;
630         sg_io_hdr_t *hp;
631         unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
632         int timeout;
633         unsigned long ul_timeout;
634
635         if (count < SZ_SG_IO_HDR)
636                 return -EINVAL;
637         if (!access_ok(VERIFY_READ, buf, count))
638                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
639
640         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
641         if (!(srp = sg_add_request(sfp))) {
642                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
643                 return -EDOM;
644         }
645         hp = &srp->header;
646         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
647                 sg_remove_request(sfp, srp);
648                 return -EFAULT;
649         }
650         if (hp->interface_id != 'S') {
651                 sg_remove_request(sfp, srp);
652                 return -ENOSYS;
653         }
654         if (hp->flags & SG_FLAG_MMAP_IO) {
655                 if (hp->dxfer_len > sfp->reserve.bufflen) {
656                         sg_remove_request(sfp, srp);
657                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
658                 }
659                 if (hp->flags & SG_FLAG_DIRECT_IO) {
660                         sg_remove_request(sfp, srp);
661                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
662                 }
663                 if (sg_res_in_use(sfp)) {
664                         sg_remove_request(sfp, srp);
665                         return -EBUSY;  /* reserve buffer already being used */
666                 }
667         }
668         ul_timeout = msecs_to_jiffies(srp->header.timeout);
669         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
670         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
671                 sg_remove_request(sfp, srp);
672                 return -EMSGSIZE;
673         }
674         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
675                 sg_remove_request(sfp, srp);
676                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
677         }
678         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
679                 sg_remove_request(sfp, srp);
680                 return -EFAULT;
681         }
682         if (read_only &&
683             (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
684                 sg_remove_request(sfp, srp);
685                 return -EPERM;
686         }
687         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
688         if (k < 0)
689                 return k;
690         if (o_srp)
691                 *o_srp = srp;
692         return count;
693 }
694
695 static int
696 sg_common_write(Sg_fd * sfp, Sg_request * srp,
697                 unsigned char *cmnd, int timeout, int blocking)
698 {
699         int k;
700         Scsi_Request *SRpnt;
701         Sg_device *sdp = sfp->parentdp;
702         sg_io_hdr_t *hp = &srp->header;
703         request_queue_t *q;
704
705         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
706         hp->status = 0;
707         hp->masked_status = 0;
708         hp->msg_status = 0;
709         hp->info = 0;
710         hp->host_status = 0;
711         hp->driver_status = 0;
712         hp->resid = 0;
713         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
714                           (int) cmnd[0], (int) hp->cmd_len));
715
716         if ((k = sg_start_req(srp))) {
717                 SCSI_LOG_TIMEOUT(1, printk("sg_write: start_req err=%d\n", k));
718                 sg_finish_rem_req(srp);
719                 return k;       /* probably out of space --> ENOMEM */
720         }
721         if ((k = sg_write_xfer(srp))) {
722                 SCSI_LOG_TIMEOUT(1, printk("sg_write: write_xfer, bad address\n"));
723                 sg_finish_rem_req(srp);
724                 return k;
725         }
726         if (sdp->detached) {
727                 sg_finish_rem_req(srp);
728                 return -ENODEV;
729         }
730         SRpnt = scsi_allocate_request(sdp->device, GFP_ATOMIC);
731         if (SRpnt == NULL) {
732                 SCSI_LOG_TIMEOUT(1, printk("sg_write: no mem\n"));
733                 sg_finish_rem_req(srp);
734                 return -ENOMEM;
735         }
736
737         srp->my_cmdp = SRpnt;
738         q = SRpnt->sr_device->request_queue;
739         SRpnt->sr_request->rq_disk = sdp->disk;
740         SRpnt->sr_sense_buffer[0] = 0;
741         SRpnt->sr_cmd_len = hp->cmd_len;
742         SRpnt->sr_use_sg = srp->data.k_use_sg;
743         SRpnt->sr_sglist_len = srp->data.sglist_len;
744         SRpnt->sr_bufflen = srp->data.bufflen;
745         SRpnt->sr_underflow = 0;
746         SRpnt->sr_buffer = srp->data.buffer;
747         switch (hp->dxfer_direction) {
748         case SG_DXFER_TO_FROM_DEV:
749         case SG_DXFER_FROM_DEV:
750                 SRpnt->sr_data_direction = DMA_FROM_DEVICE;
751                 break;
752         case SG_DXFER_TO_DEV:
753                 SRpnt->sr_data_direction = DMA_TO_DEVICE;
754                 break;
755         case SG_DXFER_UNKNOWN:
756                 SRpnt->sr_data_direction = DMA_BIDIRECTIONAL;
757                 break;
758         default:
759                 SRpnt->sr_data_direction = DMA_NONE;
760                 break;
761         }
762         SRpnt->upper_private_data = srp;
763         srp->data.k_use_sg = 0;
764         srp->data.sglist_len = 0;
765         srp->data.bufflen = 0;
766         srp->data.buffer = NULL;
767         hp->duration = jiffies_to_msecs(jiffies);
768 /* Now send everything of to mid-level. The next time we hear about this
769    packet is when sg_cmd_done() is called (i.e. a callback). */
770         scsi_do_req(SRpnt, (void *) cmnd,
771                     (void *) SRpnt->sr_buffer, hp->dxfer_len,
772                     sg_cmd_done, timeout, SG_DEFAULT_RETRIES);
773         /* dxfer_len overwrites SRpnt->sr_bufflen, hence need for b_malloc_len */
774         return 0;
775 }
776
777 static int
778 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
779 {
780         unsigned long iflags;
781         int done;
782
783         read_lock_irqsave(&sfp->rq_list_lock, iflags);
784         done = srp->done;
785         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
786         return done;
787 }
788
789 static int
790 sg_ioctl(struct inode *inode, struct file *filp,
791          unsigned int cmd_in, unsigned long arg)
792 {
793         void __user *p = (void __user *)arg;
794         int __user *ip = p;
795         int result, val, read_only;
796         Sg_device *sdp;
797         Sg_fd *sfp;
798         Sg_request *srp;
799         unsigned long iflags;
800
801         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
802                 return -ENXIO;
803         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
804                                    sdp->disk->disk_name, (int) cmd_in));
805         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
806
807         switch (cmd_in) {
808         case SG_IO:
809                 {
810                         int blocking = 1;       /* ignore O_NONBLOCK flag */
811
812                         if (sdp->detached)
813                                 return -ENODEV;
814                         if (!scsi_block_when_processing_errors(sdp->device))
815                                 return -ENXIO;
816                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
817                                 return -EFAULT;
818                         result =
819                             sg_new_write(sfp, p, SZ_SG_IO_HDR,
820                                          blocking, read_only, &srp);
821                         if (result < 0)
822                                 return result;
823                         srp->sg_io_owned = 1;
824                         while (1) {
825                                 result = 0;     /* following macro to beat race condition */
826                                 __wait_event_interruptible(sfp->read_wait,
827                                         (sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
828                                                            result);
829                                 if (sdp->detached)
830                                         return -ENODEV;
831                                 if (sfp->closed)
832                                         return 0;       /* request packet dropped already */
833                                 if (0 == result)
834                                         break;
835                                 srp->orphan = 1;
836                                 return result;  /* -ERESTARTSYS because signal hit process */
837                         }
838                         write_lock_irqsave(&sfp->rq_list_lock, iflags);
839                         srp->done = 2;
840                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
841                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
842                         return (result < 0) ? result : 0;
843                 }
844         case SG_SET_TIMEOUT:
845                 result = get_user(val, ip);
846                 if (result)
847                         return result;
848                 if (val < 0)
849                         return -EIO;
850                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
851                     val = MULDIV (INT_MAX, USER_HZ, HZ);
852                 sfp->timeout_user = val;
853                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
854
855                 return 0;
856         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
857                                 /* strange ..., for backward compatibility */
858                 return sfp->timeout_user;
859         case SG_SET_FORCE_LOW_DMA:
860                 result = get_user(val, ip);
861                 if (result)
862                         return result;
863                 if (val) {
864                         sfp->low_dma = 1;
865                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
866                                 val = (int) sfp->reserve.bufflen;
867                                 sg_remove_scat(&sfp->reserve);
868                                 sg_build_reserve(sfp, val);
869                         }
870                 } else {
871                         if (sdp->detached)
872                                 return -ENODEV;
873                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
874                 }
875                 return 0;
876         case SG_GET_LOW_DMA:
877                 return put_user((int) sfp->low_dma, ip);
878         case SG_GET_SCSI_ID:
879                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
880                         return -EFAULT;
881                 else {
882                         sg_scsi_id_t __user *sg_idp = p;
883
884                         if (sdp->detached)
885                                 return -ENODEV;
886                         __put_user((int) sdp->device->host->host_no,
887                                    &sg_idp->host_no);
888                         __put_user((int) sdp->device->channel,
889                                    &sg_idp->channel);
890                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
891                         __put_user((int) sdp->device->lun, &sg_idp->lun);
892                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
893                         __put_user((short) sdp->device->host->cmd_per_lun,
894                                    &sg_idp->h_cmd_per_lun);
895                         __put_user((short) sdp->device->queue_depth,
896                                    &sg_idp->d_queue_depth);
897                         __put_user(0, &sg_idp->unused[0]);
898                         __put_user(0, &sg_idp->unused[1]);
899                         return 0;
900                 }
901         case SG_SET_FORCE_PACK_ID:
902                 result = get_user(val, ip);
903                 if (result)
904                         return result;
905                 sfp->force_packid = val ? 1 : 0;
906                 return 0;
907         case SG_GET_PACK_ID:
908                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
909                         return -EFAULT;
910                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
911                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
912                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
913                                 read_unlock_irqrestore(&sfp->rq_list_lock,
914                                                        iflags);
915                                 __put_user(srp->header.pack_id, ip);
916                                 return 0;
917                         }
918                 }
919                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
920                 __put_user(-1, ip);
921                 return 0;
922         case SG_GET_NUM_WAITING:
923                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
924                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
925                         if ((1 == srp->done) && (!srp->sg_io_owned))
926                                 ++val;
927                 }
928                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
929                 return put_user(val, ip);
930         case SG_GET_SG_TABLESIZE:
931                 return put_user(sdp->sg_tablesize, ip);
932         case SG_SET_RESERVED_SIZE:
933                 result = get_user(val, ip);
934                 if (result)
935                         return result;
936                 if (val < 0)
937                         return -EINVAL;
938                 if (val != sfp->reserve.bufflen) {
939                         if (sg_res_in_use(sfp) || sfp->mmap_called)
940                                 return -EBUSY;
941                         sg_remove_scat(&sfp->reserve);
942                         sg_build_reserve(sfp, val);
943                 }
944                 return 0;
945         case SG_GET_RESERVED_SIZE:
946                 val = (int) sfp->reserve.bufflen;
947                 return put_user(val, ip);
948         case SG_SET_COMMAND_Q:
949                 result = get_user(val, ip);
950                 if (result)
951                         return result;
952                 sfp->cmd_q = val ? 1 : 0;
953                 return 0;
954         case SG_GET_COMMAND_Q:
955                 return put_user((int) sfp->cmd_q, ip);
956         case SG_SET_KEEP_ORPHAN:
957                 result = get_user(val, ip);
958                 if (result)
959                         return result;
960                 sfp->keep_orphan = val;
961                 return 0;
962         case SG_GET_KEEP_ORPHAN:
963                 return put_user((int) sfp->keep_orphan, ip);
964         case SG_NEXT_CMD_LEN:
965                 result = get_user(val, ip);
966                 if (result)
967                         return result;
968                 sfp->next_cmd_len = (val > 0) ? val : 0;
969                 return 0;
970         case SG_GET_VERSION_NUM:
971                 return put_user(sg_version_num, ip);
972         case SG_GET_ACCESS_COUNT:
973                 /* faked - we don't have a real access count anymore */
974                 val = (sdp->device ? 1 : 0);
975                 return put_user(val, ip);
976         case SG_GET_REQUEST_TABLE:
977                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
978                         return -EFAULT;
979                 else {
980                         sg_req_info_t *rinfo;
981                         unsigned int ms;
982
983                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
984                                                                 GFP_KERNEL);
985                         if (!rinfo)
986                                 return -ENOMEM;
987                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
988                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
989                              ++val, srp = srp ? srp->nextrp : srp) {
990                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
991                                 if (srp) {
992                                         rinfo[val].req_state = srp->done + 1;
993                                         rinfo[val].problem =
994                                             srp->header.masked_status & 
995                                             srp->header.host_status & 
996                                             srp->header.driver_status;
997                                         if (srp->done)
998                                                 rinfo[val].duration =
999                                                         srp->header.duration;
1000                                         else {
1001                                                 ms = jiffies_to_msecs(jiffies);
1002                                                 rinfo[val].duration =
1003                                                     (ms > srp->header.duration) ?
1004                                                     (ms - srp->header.duration) : 0;
1005                                         }
1006                                         rinfo[val].orphan = srp->orphan;
1007                                         rinfo[val].sg_io_owned =
1008                                                         srp->sg_io_owned;
1009                                         rinfo[val].pack_id =
1010                                                         srp->header.pack_id;
1011                                         rinfo[val].usr_ptr =
1012                                                         srp->header.usr_ptr;
1013                                 }
1014                         }
1015                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1016                         result = __copy_to_user(p, rinfo, 
1017                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1018                         result = result ? -EFAULT : 0;
1019                         kfree(rinfo);
1020                         return result;
1021                 }
1022         case SG_EMULATED_HOST:
1023                 if (sdp->detached)
1024                         return -ENODEV;
1025                 return put_user(sdp->device->host->hostt->emulated, ip);
1026         case SG_SCSI_RESET:
1027                 if (sdp->detached)
1028                         return -ENODEV;
1029                 if (filp->f_flags & O_NONBLOCK) {
1030                         if (scsi_host_in_recovery(sdp->device->host))
1031                                 return -EBUSY;
1032                 } else if (!scsi_block_when_processing_errors(sdp->device))
1033                         return -EBUSY;
1034                 result = get_user(val, ip);
1035                 if (result)
1036                         return result;
1037                 if (SG_SCSI_RESET_NOTHING == val)
1038                         return 0;
1039                 switch (val) {
1040                 case SG_SCSI_RESET_DEVICE:
1041                         val = SCSI_TRY_RESET_DEVICE;
1042                         break;
1043                 case SG_SCSI_RESET_BUS:
1044                         val = SCSI_TRY_RESET_BUS;
1045                         break;
1046                 case SG_SCSI_RESET_HOST:
1047                         val = SCSI_TRY_RESET_HOST;
1048                         break;
1049                 default:
1050                         return -EINVAL;
1051                 }
1052                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1053                         return -EACCES;
1054                 return (scsi_reset_provider(sdp->device, val) ==
1055                         SUCCESS) ? 0 : -EIO;
1056         case SCSI_IOCTL_SEND_COMMAND:
1057                 if (sdp->detached)
1058                         return -ENODEV;
1059                 if (read_only) {
1060                         unsigned char opcode = WRITE_6;
1061                         Scsi_Ioctl_Command __user *siocp = p;
1062
1063                         if (copy_from_user(&opcode, siocp->data, 1))
1064                                 return -EFAULT;
1065                         if (!sg_allow_access(opcode, sdp->device->type))
1066                                 return -EPERM;
1067                 }
1068                 return scsi_ioctl_send_command(sdp->device, p);
1069         case SG_SET_DEBUG:
1070                 result = get_user(val, ip);
1071                 if (result)
1072                         return result;
1073                 sdp->sgdebug = (char) val;
1074                 return 0;
1075         case SCSI_IOCTL_GET_IDLUN:
1076         case SCSI_IOCTL_GET_BUS_NUMBER:
1077         case SCSI_IOCTL_PROBE_HOST:
1078         case SG_GET_TRANSFORM:
1079                 if (sdp->detached)
1080                         return -ENODEV;
1081                 return scsi_ioctl(sdp->device, cmd_in, p);
1082         default:
1083                 if (read_only)
1084                         return -EPERM;  /* don't know so take safe approach */
1085                 return scsi_ioctl(sdp->device, cmd_in, p);
1086         }
1087 }
1088
1089 #ifdef CONFIG_COMPAT
1090 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1091 {
1092         Sg_device *sdp;
1093         Sg_fd *sfp;
1094         struct scsi_device *sdev;
1095
1096         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1097                 return -ENXIO;
1098
1099         sdev = sdp->device;
1100         if (sdev->host->hostt->compat_ioctl) { 
1101                 int ret;
1102
1103                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1104
1105                 return ret;
1106         }
1107         
1108         return -ENOIOCTLCMD;
1109 }
1110 #endif
1111
1112 static unsigned int
1113 sg_poll(struct file *filp, poll_table * wait)
1114 {
1115         unsigned int res = 0;
1116         Sg_device *sdp;
1117         Sg_fd *sfp;
1118         Sg_request *srp;
1119         int count = 0;
1120         unsigned long iflags;
1121
1122         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1123             || sfp->closed)
1124                 return POLLERR;
1125         poll_wait(filp, &sfp->read_wait, wait);
1126         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1127         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1128                 /* if any read waiting, flag it */
1129                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1130                         res = POLLIN | POLLRDNORM;
1131                 ++count;
1132         }
1133         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1134
1135         if (sdp->detached)
1136                 res |= POLLHUP;
1137         else if (!sfp->cmd_q) {
1138                 if (0 == count)
1139                         res |= POLLOUT | POLLWRNORM;
1140         } else if (count < SG_MAX_QUEUE)
1141                 res |= POLLOUT | POLLWRNORM;
1142         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1143                                    sdp->disk->disk_name, (int) res));
1144         return res;
1145 }
1146
1147 static int
1148 sg_fasync(int fd, struct file *filp, int mode)
1149 {
1150         int retval;
1151         Sg_device *sdp;
1152         Sg_fd *sfp;
1153
1154         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1155                 return -ENXIO;
1156         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1157                                    sdp->disk->disk_name, mode));
1158
1159         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1160         return (retval < 0) ? retval : 0;
1161 }
1162
1163 static inline unsigned char *
1164 sg_scatg2virt(const struct scatterlist *sclp)
1165 {
1166         return (sclp && sclp->page) ?
1167             (unsigned char *) page_address(sclp->page) + sclp->offset : NULL;
1168 }
1169
1170 /* When startFinish==1 increments page counts for pages other than the 
1171    first of scatter gather elements obtained from __get_free_pages().
1172    When startFinish==0 decrements ... */
1173 static void
1174 sg_rb_correct4mmap(Sg_scatter_hold * rsv_schp, int startFinish)
1175 {
1176         void *page_ptr;
1177         struct page *page;
1178         int k, m;
1179
1180         SCSI_LOG_TIMEOUT(3, printk("sg_rb_correct4mmap: startFinish=%d, scatg=%d\n", 
1181                                    startFinish, rsv_schp->k_use_sg));
1182         /* N.B. correction _not_ applied to base page of each allocation */
1183         if (rsv_schp->k_use_sg) {       /* reserve buffer is a scatter gather list */
1184                 struct scatterlist *sclp = rsv_schp->buffer;
1185
1186                 for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
1187                         for (m = PAGE_SIZE; m < sclp->length; m += PAGE_SIZE) {
1188                                 page_ptr = sg_scatg2virt(sclp) + m;
1189                                 page = virt_to_page(page_ptr);
1190                                 if (startFinish)
1191                                         get_page(page);
1192                                 else {
1193                                         if (page_count(page) > 0)
1194                                                 __put_page(page);
1195                                 }
1196                         }
1197                 }
1198         } else {                /* reserve buffer is just a single allocation */
1199                 for (m = PAGE_SIZE; m < rsv_schp->bufflen; m += PAGE_SIZE) {
1200                         page_ptr = (unsigned char *) rsv_schp->buffer + m;
1201                         page = virt_to_page(page_ptr);
1202                         if (startFinish)
1203                                 get_page(page);
1204                         else {
1205                                 if (page_count(page) > 0)
1206                                         __put_page(page);
1207                         }
1208                 }
1209         }
1210 }
1211
1212 static struct page *
1213 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
1214 {
1215         Sg_fd *sfp;
1216         struct page *page = NOPAGE_SIGBUS;
1217         void *page_ptr = NULL;
1218         unsigned long offset;
1219         Sg_scatter_hold *rsv_schp;
1220
1221         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1222                 return page;
1223         rsv_schp = &sfp->reserve;
1224         offset = addr - vma->vm_start;
1225         if (offset >= rsv_schp->bufflen)
1226                 return page;
1227         SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
1228                                    offset, rsv_schp->k_use_sg));
1229         if (rsv_schp->k_use_sg) {       /* reserve buffer is a scatter gather list */
1230                 int k;
1231                 unsigned long sa = vma->vm_start;
1232                 unsigned long len;
1233                 struct scatterlist *sclp = rsv_schp->buffer;
1234
1235                 for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1236                      ++k, ++sclp) {
1237                         len = vma->vm_end - sa;
1238                         len = (len < sclp->length) ? len : sclp->length;
1239                         if (offset < len) {
1240                                 page_ptr = sg_scatg2virt(sclp) + offset;
1241                                 page = virt_to_page(page_ptr);
1242                                 get_page(page); /* increment page count */
1243                                 break;
1244                         }
1245                         sa += len;
1246                         offset -= len;
1247                 }
1248         } else {                /* reserve buffer is just a single allocation */
1249                 page_ptr = (unsigned char *) rsv_schp->buffer + offset;
1250                 page = virt_to_page(page_ptr);
1251                 get_page(page); /* increment page count */
1252         }
1253         if (type)
1254                 *type = VM_FAULT_MINOR;
1255         return page;
1256 }
1257
1258 static struct vm_operations_struct sg_mmap_vm_ops = {
1259         .nopage = sg_vma_nopage,
1260 };
1261
1262 static int
1263 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1264 {
1265         Sg_fd *sfp;
1266         unsigned long req_sz;
1267         Sg_scatter_hold *rsv_schp;
1268
1269         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1270                 return -ENXIO;
1271         req_sz = vma->vm_end - vma->vm_start;
1272         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1273                                    (void *) vma->vm_start, (int) req_sz));
1274         if (vma->vm_pgoff)
1275                 return -EINVAL; /* want no offset */
1276         rsv_schp = &sfp->reserve;
1277         if (req_sz > rsv_schp->bufflen)
1278                 return -ENOMEM; /* cannot map more than reserved buffer */
1279
1280         if (rsv_schp->k_use_sg) { /* reserve buffer is a scatter gather list */
1281                 int k;
1282                 unsigned long sa = vma->vm_start;
1283                 unsigned long len;
1284                 struct scatterlist *sclp = rsv_schp->buffer;
1285
1286                 for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1287                      ++k, ++sclp) {
1288                         if (0 != sclp->offset)
1289                                 return -EFAULT; /* non page aligned memory ?? */
1290                         len = vma->vm_end - sa;
1291                         len = (len < sclp->length) ? len : sclp->length;
1292                         sa += len;
1293                 }
1294         } else {        /* reserve buffer is just a single allocation */
1295                 if ((unsigned long) rsv_schp->buffer & (PAGE_SIZE - 1))
1296                         return -EFAULT; /* non page aligned memory ?? */
1297         }
1298         if (0 == sfp->mmap_called) {
1299                 sg_rb_correct4mmap(rsv_schp, 1);        /* do only once per fd lifetime */
1300                 sfp->mmap_called = 1;
1301         }
1302         vma->vm_flags |= VM_RESERVED;
1303         vma->vm_private_data = sfp;
1304         vma->vm_ops = &sg_mmap_vm_ops;
1305         return 0;
1306 }
1307
1308 /* This function is a "bottom half" handler that is called by the
1309  * mid level when a command is completed (or has failed). */
1310 static void
1311 sg_cmd_done(Scsi_Cmnd * SCpnt)
1312 {
1313         Scsi_Request *SRpnt = NULL;
1314         Sg_device *sdp = NULL;
1315         Sg_fd *sfp;
1316         Sg_request *srp = NULL;
1317         unsigned long iflags;
1318         unsigned int ms;
1319
1320         if (SCpnt && (SRpnt = SCpnt->sc_request))
1321                 srp = (Sg_request *) SRpnt->upper_private_data;
1322         if (NULL == srp) {
1323                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1324                 if (SRpnt)
1325                         scsi_release_request(SRpnt);
1326                 return;
1327         }
1328         sfp = srp->parentfp;
1329         if (sfp)
1330                 sdp = sfp->parentdp;
1331         if ((NULL == sdp) || sdp->detached) {
1332                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1333                 scsi_release_request(SRpnt);
1334                 return;
1335         }
1336
1337         /* First transfer ownership of data buffers to sg_device object. */
1338         srp->data.k_use_sg = SRpnt->sr_use_sg;
1339         srp->data.sglist_len = SRpnt->sr_sglist_len;
1340         srp->data.bufflen = SRpnt->sr_bufflen;
1341         srp->data.buffer = SRpnt->sr_buffer;
1342         /* now clear out request structure */
1343         SRpnt->sr_use_sg = 0;
1344         SRpnt->sr_sglist_len = 0;
1345         SRpnt->sr_bufflen = 0;
1346         SRpnt->sr_buffer = NULL;
1347         SRpnt->sr_underflow = 0;
1348         SRpnt->sr_request->rq_disk = NULL; /* "sg" _disowns_ request blk */
1349
1350         srp->my_cmdp = NULL;
1351
1352         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1353                 sdp->disk->disk_name, srp->header.pack_id, (int) SRpnt->sr_result));
1354         srp->header.resid = SCpnt->resid;
1355         ms = jiffies_to_msecs(jiffies);
1356         srp->header.duration = (ms > srp->header.duration) ?
1357                                 (ms - srp->header.duration) : 0;
1358         if (0 != SRpnt->sr_result) {
1359                 struct scsi_sense_hdr sshdr;
1360
1361                 memcpy(srp->sense_b, SRpnt->sr_sense_buffer,
1362                        sizeof (srp->sense_b));
1363                 srp->header.status = 0xff & SRpnt->sr_result;
1364                 srp->header.masked_status = status_byte(SRpnt->sr_result);
1365                 srp->header.msg_status = msg_byte(SRpnt->sr_result);
1366                 srp->header.host_status = host_byte(SRpnt->sr_result);
1367                 srp->header.driver_status = driver_byte(SRpnt->sr_result);
1368                 if ((sdp->sgdebug > 0) &&
1369                     ((CHECK_CONDITION == srp->header.masked_status) ||
1370                      (COMMAND_TERMINATED == srp->header.masked_status)))
1371                         scsi_print_req_sense("sg_cmd_done", SRpnt);
1372
1373                 /* Following if statement is a patch supplied by Eric Youngdale */
1374                 if (driver_byte(SRpnt->sr_result) != 0
1375                     && scsi_command_normalize_sense(SCpnt, &sshdr)
1376                     && !scsi_sense_is_deferred(&sshdr)
1377                     && sshdr.sense_key == UNIT_ATTENTION
1378                     && sdp->device->removable) {
1379                         /* Detected possible disc change. Set the bit - this */
1380                         /* may be used if there are filesystems using this device */
1381                         sdp->device->changed = 1;
1382                 }
1383         }
1384         /* Rely on write phase to clean out srp status values, so no "else" */
1385
1386         scsi_release_request(SRpnt);
1387         SRpnt = NULL;
1388         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1389                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1390                 sg_finish_rem_req(srp);
1391                 srp = NULL;
1392                 if (NULL == sfp->headrp) {
1393                         SCSI_LOG_TIMEOUT(1, printk("sg...bh: already closed, final cleanup\n"));
1394                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1395                                 scsi_device_put(sdp->device);
1396                         }
1397                         sfp = NULL;
1398                 }
1399         } else if (srp && srp->orphan) {
1400                 if (sfp->keep_orphan)
1401                         srp->sg_io_owned = 0;
1402                 else {
1403                         sg_finish_rem_req(srp);
1404                         srp = NULL;
1405                 }
1406         }
1407         if (sfp && srp) {
1408                 /* Now wake up any sg_read() that is waiting for this packet. */
1409                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1410                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1411                 srp->done = 1;
1412                 wake_up_interruptible(&sfp->read_wait);
1413                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1414         }
1415 }
1416
1417 static struct file_operations sg_fops = {
1418         .owner = THIS_MODULE,
1419         .read = sg_read,
1420         .write = sg_write,
1421         .poll = sg_poll,
1422         .ioctl = sg_ioctl,
1423 #ifdef CONFIG_COMPAT
1424         .compat_ioctl = sg_compat_ioctl,
1425 #endif
1426         .open = sg_open,
1427         .mmap = sg_mmap,
1428         .release = sg_release,
1429         .fasync = sg_fasync,
1430 };
1431
1432 static struct class *sg_sysfs_class;
1433
1434 static int sg_sysfs_valid = 0;
1435
1436 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1437 {
1438         Sg_device *sdp;
1439         unsigned long iflags;
1440         void *old_sg_dev_arr = NULL;
1441         int k, error;
1442
1443         sdp = kmalloc(sizeof(Sg_device), GFP_KERNEL);
1444         if (!sdp) {
1445                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1446                 return -ENOMEM;
1447         }
1448
1449         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1450         if (unlikely(sg_nr_dev >= sg_dev_max)) {        /* try to resize */
1451                 Sg_device **tmp_da;
1452                 int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
1453                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1454
1455                 tmp_da = kmalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
1456                 if (unlikely(!tmp_da))
1457                         goto expand_failed;
1458
1459                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
1460                 memset(tmp_da, 0, tmp_dev_max * sizeof(Sg_device *));
1461                 memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
1462                 old_sg_dev_arr = sg_dev_arr;
1463                 sg_dev_arr = tmp_da;
1464                 sg_dev_max = tmp_dev_max;
1465         }
1466
1467         for (k = 0; k < sg_dev_max; k++)
1468                 if (!sg_dev_arr[k])
1469                         break;
1470         if (unlikely(k >= SG_MAX_DEVS))
1471                 goto overflow;
1472
1473         memset(sdp, 0, sizeof(*sdp));
1474         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1475         sprintf(disk->disk_name, "sg%d", k);
1476         disk->first_minor = k;
1477         sdp->disk = disk;
1478         sdp->device = scsidp;
1479         init_waitqueue_head(&sdp->o_excl_wait);
1480         sdp->sg_tablesize = scsidp->host ? scsidp->host->sg_tablesize : 0;
1481
1482         sg_nr_dev++;
1483         sg_dev_arr[k] = sdp;
1484         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1485         error = k;
1486
1487  out:
1488         if (error < 0)
1489                 kfree(sdp);
1490         kfree(old_sg_dev_arr);
1491         return error;
1492
1493  expand_failed:
1494         printk(KERN_WARNING "sg_alloc: device array cannot be resized\n");
1495         error = -ENOMEM;
1496         goto out;
1497
1498  overflow:
1499         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1500         printk(KERN_WARNING
1501                "Unable to attach sg device <%d, %d, %d, %d> type=%d, minor "
1502                "number exceeds %d\n", scsidp->host->host_no, scsidp->channel,
1503                scsidp->id, scsidp->lun, scsidp->type, SG_MAX_DEVS - 1);
1504         error = -ENODEV;
1505         goto out;
1506 }
1507
1508 static int
1509 sg_add(struct class_device *cl_dev)
1510 {
1511         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1512         struct gendisk *disk;
1513         Sg_device *sdp = NULL;
1514         struct cdev * cdev = NULL;
1515         int error, k;
1516
1517         disk = alloc_disk(1);
1518         if (!disk) {
1519                 printk(KERN_WARNING "alloc_disk failed\n");
1520                 return -ENOMEM;
1521         }
1522         disk->major = SCSI_GENERIC_MAJOR;
1523
1524         error = -ENOMEM;
1525         cdev = cdev_alloc();
1526         if (!cdev) {
1527                 printk(KERN_WARNING "cdev_alloc failed\n");
1528                 goto out;
1529         }
1530         cdev->owner = THIS_MODULE;
1531         cdev->ops = &sg_fops;
1532
1533         error = sg_alloc(disk, scsidp);
1534         if (error < 0) {
1535                 printk(KERN_WARNING "sg_alloc failed\n");
1536                 goto out;
1537         }
1538         k = error;
1539         sdp = sg_dev_arr[k];
1540
1541         devfs_mk_cdev(MKDEV(SCSI_GENERIC_MAJOR, k),
1542                         S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP,
1543                         "%s/generic", scsidp->devfs_name);
1544         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1545         if (error) {
1546                 devfs_remove("%s/generic", scsidp->devfs_name);
1547                 goto out;
1548         }
1549         sdp->cdev = cdev;
1550         if (sg_sysfs_valid) {
1551                 struct class_device * sg_class_member;
1552
1553                 sg_class_member = class_device_create(sg_sysfs_class,
1554                                 MKDEV(SCSI_GENERIC_MAJOR, k), 
1555                                 cl_dev->dev, "%s", 
1556                                 disk->disk_name);
1557                 if (IS_ERR(sg_class_member))
1558                         printk(KERN_WARNING "sg_add: "
1559                                 "class_device_create failed\n");
1560                 class_set_devdata(sg_class_member, sdp);
1561                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj, 
1562                                           &sg_class_member->kobj, "generic");
1563                 if (error)
1564                         printk(KERN_ERR "sg_add: unable to make symlink "
1565                                         "'generic' back to sg%d\n", k);
1566         } else
1567                 printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1568
1569         printk(KERN_NOTICE
1570                "Attached scsi generic sg%d at scsi%d, channel"
1571                " %d, id %d, lun %d,  type %d\n", k,
1572                scsidp->host->host_no, scsidp->channel, scsidp->id,
1573                scsidp->lun, scsidp->type);
1574
1575         return 0;
1576
1577 out:
1578         put_disk(disk);
1579         if (cdev)
1580                 cdev_del(cdev);
1581         return error;
1582 }
1583
1584 static void
1585 sg_remove(struct class_device *cl_dev)
1586 {
1587         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1588         Sg_device *sdp = NULL;
1589         unsigned long iflags;
1590         Sg_fd *sfp;
1591         Sg_fd *tsfp;
1592         Sg_request *srp;
1593         Sg_request *tsrp;
1594         int k, delay;
1595
1596         if (NULL == sg_dev_arr)
1597                 return;
1598         delay = 0;
1599         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1600         for (k = 0; k < sg_dev_max; k++) {
1601                 sdp = sg_dev_arr[k];
1602                 if ((NULL == sdp) || (sdp->device != scsidp))
1603                         continue;       /* dirty but lowers nesting */
1604                 if (sdp->headfp) {
1605                         sdp->detached = 1;
1606                         for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1607                                 tsfp = sfp->nextfp;
1608                                 for (srp = sfp->headrp; srp; srp = tsrp) {
1609                                         tsrp = srp->nextrp;
1610                                         if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1611                                                 sg_finish_rem_req(srp);
1612                                 }
1613                                 if (sfp->closed) {
1614                                         scsi_device_put(sdp->device);
1615                                         __sg_remove_sfp(sdp, sfp);
1616                                 } else {
1617                                         delay = 1;
1618                                         wake_up_interruptible(&sfp->read_wait);
1619                                         kill_fasync(&sfp->async_qp, SIGPOLL,
1620                                                     POLL_HUP);
1621                                 }
1622                         }
1623                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d, dirty\n", k));
1624                         if (NULL == sdp->headfp) {
1625                                 sg_dev_arr[k] = NULL;
1626                         }
1627                 } else {        /* nothing active, simple case */
1628                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d\n", k));
1629                         sg_dev_arr[k] = NULL;
1630                 }
1631                 sg_nr_dev--;
1632                 break;
1633         }
1634         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1635
1636         if (sdp) {
1637                 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1638                 class_device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, k));
1639                 cdev_del(sdp->cdev);
1640                 sdp->cdev = NULL;
1641                 devfs_remove("%s/generic", scsidp->devfs_name);
1642                 put_disk(sdp->disk);
1643                 sdp->disk = NULL;
1644                 if (NULL == sdp->headfp)
1645                         kfree((char *) sdp);
1646         }
1647
1648         if (delay)
1649                 msleep(10);     /* dirty detach so delay device destruction */
1650 }
1651
1652 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
1653  * of sysfs parameters (which module_param doesn't yet support).
1654  * Sysfs parameters defined explicitly below.
1655  */
1656 module_param_named(def_reserved_size, def_reserved_size, int, S_IRUGO);
1657 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1658
1659 MODULE_AUTHOR("Douglas Gilbert");
1660 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1661 MODULE_LICENSE("GPL");
1662 MODULE_VERSION(SG_VERSION_STR);
1663
1664 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1665 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1666
1667 static int __init
1668 init_sg(void)
1669 {
1670         int rc;
1671
1672         if (def_reserved_size >= 0)
1673                 sg_big_buff = def_reserved_size;
1674
1675         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), 
1676                                     SG_MAX_DEVS, "sg");
1677         if (rc)
1678                 return rc;
1679         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1680         if ( IS_ERR(sg_sysfs_class) ) {
1681                 rc = PTR_ERR(sg_sysfs_class);
1682                 goto err_out;
1683         }
1684         sg_sysfs_valid = 1;
1685         rc = scsi_register_interface(&sg_interface);
1686         if (0 == rc) {
1687 #ifdef CONFIG_SCSI_PROC_FS
1688                 sg_proc_init();
1689 #endif                          /* CONFIG_SCSI_PROC_FS */
1690                 return 0;
1691         }
1692         class_destroy(sg_sysfs_class);
1693 err_out:
1694         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1695         return rc;
1696 }
1697
1698 static void __exit
1699 exit_sg(void)
1700 {
1701 #ifdef CONFIG_SCSI_PROC_FS
1702         sg_proc_cleanup();
1703 #endif                          /* CONFIG_SCSI_PROC_FS */
1704         scsi_unregister_interface(&sg_interface);
1705         class_destroy(sg_sysfs_class);
1706         sg_sysfs_valid = 0;
1707         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1708                                  SG_MAX_DEVS);
1709         if (sg_dev_arr != NULL) {
1710                 kfree((char *) sg_dev_arr);
1711                 sg_dev_arr = NULL;
1712         }
1713         sg_dev_max = 0;
1714 }
1715
1716 static int
1717 sg_start_req(Sg_request * srp)
1718 {
1719         int res;
1720         Sg_fd *sfp = srp->parentfp;
1721         sg_io_hdr_t *hp = &srp->header;
1722         int dxfer_len = (int) hp->dxfer_len;
1723         int dxfer_dir = hp->dxfer_direction;
1724         Sg_scatter_hold *req_schp = &srp->data;
1725         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1726
1727         SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1728         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1729                 return 0;
1730         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1731             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1732             (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1733                 res = sg_build_direct(srp, sfp, dxfer_len);
1734                 if (res <= 0)   /* -ve -> error, 0 -> done, 1 -> try indirect */
1735                         return res;
1736         }
1737         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1738                 sg_link_reserve(sfp, srp, dxfer_len);
1739         else {
1740                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1741                 if (res) {
1742                         sg_remove_scat(req_schp);
1743                         return res;
1744                 }
1745         }
1746         return 0;
1747 }
1748
1749 static void
1750 sg_finish_rem_req(Sg_request * srp)
1751 {
1752         Sg_fd *sfp = srp->parentfp;
1753         Sg_scatter_hold *req_schp = &srp->data;
1754
1755         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1756         if (srp->res_used)
1757                 sg_unlink_reserve(sfp, srp);
1758         else
1759                 sg_remove_scat(req_schp);
1760         sg_remove_request(sfp, srp);
1761 }
1762
1763 static int
1764 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1765 {
1766         int ret_sz;
1767         int elem_sz = sizeof (struct scatterlist);
1768         int sg_bufflen = tablesize * elem_sz;
1769         int mx_sc_elems = tablesize;
1770
1771         schp->buffer = sg_page_malloc(sg_bufflen, sfp->low_dma, &ret_sz);
1772         if (!schp->buffer)
1773                 return -ENOMEM;
1774         else if (ret_sz != sg_bufflen) {
1775                 sg_bufflen = ret_sz;
1776                 mx_sc_elems = sg_bufflen / elem_sz;
1777         }
1778         schp->sglist_len = sg_bufflen;
1779         memset(schp->buffer, 0, sg_bufflen);
1780         return mx_sc_elems;     /* number of scat_gath elements allocated */
1781 }
1782
1783 #ifdef SG_ALLOW_DIO_CODE
1784 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1785         /* hopefully this generic code will moved to a library */
1786
1787 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1788    - mapping of all pages not successful
1789    - any page is above max_pfn
1790    (i.e., either completely successful or fails)
1791 */
1792 static int 
1793 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages, 
1794                   unsigned long uaddr, size_t count, int rw,
1795                   unsigned long max_pfn)
1796 {
1797         unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
1798         unsigned long start = uaddr >> PAGE_SHIFT;
1799         const int nr_pages = end - start;
1800         int res, i, j;
1801         struct page **pages;
1802
1803         /* User attempted Overflow! */
1804         if ((uaddr + count) < uaddr)
1805                 return -EINVAL;
1806
1807         /* Too big */
1808         if (nr_pages > max_pages)
1809                 return -ENOMEM;
1810
1811         /* Hmm? */
1812         if (count == 0)
1813                 return 0;
1814
1815         if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1816                 return -ENOMEM;
1817
1818         /* Try to fault in all of the necessary pages */
1819         down_read(&current->mm->mmap_sem);
1820         /* rw==READ means read from drive, write into memory area */
1821         res = get_user_pages(
1822                 current,
1823                 current->mm,
1824                 uaddr,
1825                 nr_pages,
1826                 rw == READ,
1827                 0, /* don't force */
1828                 pages,
1829                 NULL);
1830         up_read(&current->mm->mmap_sem);
1831
1832         /* Errors and no page mapped should return here */
1833         if (res < nr_pages)
1834                 goto out_unmap;
1835
1836         for (i=0; i < nr_pages; i++) {
1837                 /* FIXME: flush superflous for rw==READ,
1838                  * probably wrong function for rw==WRITE
1839                  */
1840                 flush_dcache_page(pages[i]);
1841                 if (page_to_pfn(pages[i]) > max_pfn)
1842                         goto out_unlock;
1843                 /* ?? Is locking needed? I don't think so */
1844                 /* if (TestSetPageLocked(pages[i]))
1845                    goto out_unlock; */
1846         }
1847
1848         /* Populate the scatter/gather list */
1849         sgl[0].page = pages[0]; 
1850         sgl[0].offset = uaddr & ~PAGE_MASK;
1851         if (nr_pages > 1) {
1852                 sgl[0].length = PAGE_SIZE - sgl[0].offset;
1853                 count -= sgl[0].length;
1854                 for (i=1; i < nr_pages ; i++) {
1855                         sgl[i].offset = 0;
1856                         sgl[i].page = pages[i]; 
1857                         sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1858                         count -= PAGE_SIZE;
1859                 }
1860         }
1861         else {
1862                 sgl[0].length = count;
1863         }
1864
1865         kfree(pages);
1866         return nr_pages;
1867
1868  out_unlock:
1869         /* for (j=0; j < i; j++)
1870            unlock_page(pages[j]); */
1871         res = 0;
1872  out_unmap:
1873         if (res > 0)
1874                 for (j=0; j < res; j++)
1875                         page_cache_release(pages[j]);
1876         kfree(pages);
1877         return res;
1878 }
1879
1880
1881 /* And unmap them... */
1882 static int 
1883 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1884                     int dirtied)
1885 {
1886         int i;
1887
1888         for (i=0; i < nr_pages; i++) {
1889                 if (dirtied && !PageReserved(sgl[i].page))
1890                         SetPageDirty(sgl[i].page);
1891                 /* unlock_page(sgl[i].page); */
1892                 /* FIXME: cache flush missing for rw==READ
1893                  * FIXME: call the correct reference counting function
1894                  */
1895                 page_cache_release(sgl[i].page);
1896         }
1897
1898         return 0;
1899 }
1900
1901 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1902 #endif
1903
1904
1905 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1906 static int
1907 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1908 {
1909 #ifdef SG_ALLOW_DIO_CODE
1910         sg_io_hdr_t *hp = &srp->header;
1911         Sg_scatter_hold *schp = &srp->data;
1912         int sg_tablesize = sfp->parentdp->sg_tablesize;
1913         struct scatterlist *sgl;
1914         int mx_sc_elems, res;
1915         struct scsi_device *sdev = sfp->parentdp->device;
1916
1917         if (((unsigned long)hp->dxferp &
1918                         queue_dma_alignment(sdev->request_queue)) != 0)
1919                 return 1;
1920         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1921         if (mx_sc_elems <= 0) {
1922                 return 1;
1923         }
1924         sgl = (struct scatterlist *)schp->buffer;
1925         res = st_map_user_pages(sgl, mx_sc_elems, (unsigned long)hp->dxferp, dxfer_len, 
1926                                 (SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0, ULONG_MAX);
1927         if (res <= 0)
1928                 return 1;
1929         schp->k_use_sg = res;
1930         schp->dio_in_use = 1;
1931         hp->info |= SG_INFO_DIRECT_IO;
1932         return 0;
1933 #else
1934         return 1;
1935 #endif
1936 }
1937
1938 static int
1939 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1940 {
1941         int ret_sz;
1942         int blk_size = buff_size;
1943         unsigned char *p = NULL;
1944
1945         if ((blk_size < 0) || (!sfp))
1946                 return -EFAULT;
1947         if (0 == blk_size)
1948                 ++blk_size;     /* don't know why */
1949 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1950         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1951         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1952                                    buff_size, blk_size));
1953         if (blk_size <= SG_SCATTER_SZ) {
1954                 p = sg_page_malloc(blk_size, sfp->low_dma, &ret_sz);
1955                 if (!p)
1956                         return -ENOMEM;
1957                 if (blk_size == ret_sz) {       /* got it on the first attempt */
1958                         schp->k_use_sg = 0;
1959                         schp->buffer = p;
1960                         schp->bufflen = blk_size;
1961                         schp->b_malloc_len = blk_size;
1962                         return 0;
1963                 }
1964         } else {
1965                 p = sg_page_malloc(SG_SCATTER_SZ, sfp->low_dma, &ret_sz);
1966                 if (!p)
1967                         return -ENOMEM;
1968         }
1969 /* Want some local declarations, so start new block ... */
1970         {                       /* lets try and build a scatter gather list */
1971                 struct scatterlist *sclp;
1972                 int k, rem_sz, num;
1973                 int mx_sc_elems;
1974                 int sg_tablesize = sfp->parentdp->sg_tablesize;
1975                 int first = 1;
1976
1977                 /* N.B. ret_sz carried into this block ... */
1978                 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1979                 if (mx_sc_elems < 0)
1980                         return mx_sc_elems;     /* most likely -ENOMEM */
1981
1982                 for (k = 0, sclp = schp->buffer, rem_sz = blk_size;
1983                      (rem_sz > 0) && (k < mx_sc_elems);
1984                      ++k, rem_sz -= ret_sz, ++sclp) {
1985                         if (first)
1986                                 first = 0;
1987                         else {
1988                                 num =
1989                                     (rem_sz >
1990                                      SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
1991                                 p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1992                                 if (!p)
1993                                         break;
1994                         }
1995                         sclp->page = virt_to_page(p);
1996                         sclp->offset = offset_in_page(p);
1997                         sclp->length = ret_sz;
1998
1999                         SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
2000                                           k, sg_scatg2virt(sclp), ret_sz));
2001                 }               /* end of for loop */
2002                 schp->k_use_sg = k;
2003                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
2004                 schp->bufflen = blk_size;
2005                 if (rem_sz > 0) /* must have failed */
2006                         return -ENOMEM;
2007         }
2008         return 0;
2009 }
2010
2011 static int
2012 sg_write_xfer(Sg_request * srp)
2013 {
2014         sg_io_hdr_t *hp = &srp->header;
2015         Sg_scatter_hold *schp = &srp->data;
2016         int num_xfer = 0;
2017         int j, k, onum, usglen, ksglen, res;
2018         int iovec_count = (int) hp->iovec_count;
2019         int dxfer_dir = hp->dxfer_direction;
2020         unsigned char *p;
2021         unsigned char __user *up;
2022         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2023
2024         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
2025             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2026                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
2027                 if (schp->bufflen < num_xfer)
2028                         num_xfer = schp->bufflen;
2029         }
2030         if ((num_xfer <= 0) || (schp->dio_in_use) ||
2031             (new_interface
2032              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2033                 return 0;
2034
2035         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2036                           num_xfer, iovec_count, schp->k_use_sg));
2037         if (iovec_count) {
2038                 onum = iovec_count;
2039                 if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2040                         return -EFAULT;
2041         } else
2042                 onum = 1;
2043
2044         if (0 == schp->k_use_sg) {      /* kernel has single buffer */
2045                 for (j = 0, p = schp->buffer; j < onum; ++j) {
2046                         res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
2047                         if (res)
2048                                 return res;
2049                         usglen = (num_xfer > usglen) ? usglen : num_xfer;
2050                         if (__copy_from_user(p, up, usglen))
2051                                 return -EFAULT;
2052                         p += usglen;
2053                         num_xfer -= usglen;
2054                         if (num_xfer <= 0)
2055                                 return 0;
2056                 }
2057         } else {                /* kernel using scatter gather list */
2058                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2059
2060                 ksglen = (int) sclp->length;
2061                 p = sg_scatg2virt(sclp);
2062                 for (j = 0, k = 0; j < onum; ++j) {
2063                         res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
2064                         if (res)
2065                                 return res;
2066
2067                         for (; p; ++sclp, ksglen = (int) sclp->length,
2068                                   p = sg_scatg2virt(sclp)) {
2069                                 if (usglen <= 0)
2070                                         break;
2071                                 if (ksglen > usglen) {
2072                                         if (usglen >= num_xfer) {
2073                                                 if (__copy_from_user
2074                                                     (p, up, num_xfer))
2075                                                         return -EFAULT;
2076                                                 return 0;
2077                                         }
2078                                         if (__copy_from_user(p, up, usglen))
2079                                                 return -EFAULT;
2080                                         p += usglen;
2081                                         ksglen -= usglen;
2082                                         break;
2083                                 } else {
2084                                         if (ksglen >= num_xfer) {
2085                                                 if (__copy_from_user
2086                                                     (p, up, num_xfer))
2087                                                         return -EFAULT;
2088                                                 return 0;
2089                                         }
2090                                         if (__copy_from_user(p, up, ksglen))
2091                                                 return -EFAULT;
2092                                         up += ksglen;
2093                                         usglen -= ksglen;
2094                                 }
2095                                 ++k;
2096                                 if (k >= schp->k_use_sg)
2097                                         return 0;
2098                         }
2099                 }
2100         }
2101         return 0;
2102 }
2103
2104 static int
2105 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
2106            int wr_xf, int *countp, unsigned char __user **up)
2107 {
2108         int num_xfer = (int) hp->dxfer_len;
2109         unsigned char __user *p = hp->dxferp;
2110         int count;
2111
2112         if (0 == sg_num) {
2113                 if (wr_xf && ('\0' == hp->interface_id))
2114                         count = (int) hp->flags;        /* holds "old" input_size */
2115                 else
2116                         count = num_xfer;
2117         } else {
2118                 sg_iovec_t iovec;
2119                 if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
2120                         return -EFAULT;
2121                 p = iovec.iov_base;
2122                 count = (int) iovec.iov_len;
2123         }
2124         if (!access_ok(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count))
2125                 return -EFAULT;
2126         if (up)
2127                 *up = p;
2128         if (countp)
2129                 *countp = count;
2130         return 0;
2131 }
2132
2133 static void
2134 sg_remove_scat(Sg_scatter_hold * schp)
2135 {
2136         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
2137         if (schp->buffer && (schp->sglist_len > 0)) {
2138                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2139
2140                 if (schp->dio_in_use) {
2141 #ifdef SG_ALLOW_DIO_CODE
2142                         st_unmap_user_pages(sclp, schp->k_use_sg, TRUE);
2143 #endif
2144                 } else {
2145                         int k;
2146
2147                         for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2148                              ++k, ++sclp) {
2149                                 SCSI_LOG_TIMEOUT(5, printk(
2150                                     "sg_remove_scat: k=%d, a=0x%p, len=%d\n",
2151                                     k, sg_scatg2virt(sclp), sclp->length));
2152                                 sg_page_free(sg_scatg2virt(sclp), sclp->length);
2153                                 sclp->page = NULL;
2154                                 sclp->offset = 0;
2155                                 sclp->length = 0;
2156                         }
2157                 }
2158                 sg_page_free(schp->buffer, schp->sglist_len);
2159         } else if (schp->buffer)
2160                 sg_page_free(schp->buffer, schp->b_malloc_len);
2161         memset(schp, 0, sizeof (*schp));
2162 }
2163
2164 static int
2165 sg_read_xfer(Sg_request * srp)
2166 {
2167         sg_io_hdr_t *hp = &srp->header;
2168         Sg_scatter_hold *schp = &srp->data;
2169         int num_xfer = 0;
2170         int j, k, onum, usglen, ksglen, res;
2171         int iovec_count = (int) hp->iovec_count;
2172         int dxfer_dir = hp->dxfer_direction;
2173         unsigned char *p;
2174         unsigned char __user *up;
2175         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2176
2177         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2178             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2179                 num_xfer = hp->dxfer_len;
2180                 if (schp->bufflen < num_xfer)
2181                         num_xfer = schp->bufflen;
2182         }
2183         if ((num_xfer <= 0) || (schp->dio_in_use) ||
2184             (new_interface
2185              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2186                 return 0;
2187
2188         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2189                           num_xfer, iovec_count, schp->k_use_sg));
2190         if (iovec_count) {
2191                 onum = iovec_count;
2192                 if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2193                         return -EFAULT;
2194         } else
2195                 onum = 1;
2196
2197         if (0 == schp->k_use_sg) {      /* kernel has single buffer */
2198                 for (j = 0, p = schp->buffer; j < onum; ++j) {
2199                         res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2200                         if (res)
2201                                 return res;
2202                         usglen = (num_xfer > usglen) ? usglen : num_xfer;
2203                         if (__copy_to_user(up, p, usglen))
2204                                 return -EFAULT;
2205                         p += usglen;
2206                         num_xfer -= usglen;
2207                         if (num_xfer <= 0)
2208                                 return 0;
2209                 }
2210         } else {                /* kernel using scatter gather list */
2211                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2212
2213                 ksglen = (int) sclp->length;
2214                 p = sg_scatg2virt(sclp);
2215                 for (j = 0, k = 0; j < onum; ++j) {
2216                         res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2217                         if (res)
2218                                 return res;
2219
2220                         for (; p; ++sclp, ksglen = (int) sclp->length,
2221                                   p = sg_scatg2virt(sclp)) {
2222                                 if (usglen <= 0)
2223                                         break;
2224                                 if (ksglen > usglen) {
2225                                         if (usglen >= num_xfer) {
2226                                                 if (__copy_to_user
2227                                                     (up, p, num_xfer))
2228                                                         return -EFAULT;
2229                                                 return 0;
2230                                         }
2231                                         if (__copy_to_user(up, p, usglen))
2232                                                 return -EFAULT;
2233                                         p += usglen;
2234                                         ksglen -= usglen;
2235                                         break;
2236                                 } else {
2237                                         if (ksglen >= num_xfer) {
2238                                                 if (__copy_to_user
2239                                                     (up, p, num_xfer))
2240                                                         return -EFAULT;
2241                                                 return 0;
2242                                         }
2243                                         if (__copy_to_user(up, p, ksglen))
2244                                                 return -EFAULT;
2245                                         up += ksglen;
2246                                         usglen -= ksglen;
2247                                 }
2248                                 ++k;
2249                                 if (k >= schp->k_use_sg)
2250                                         return 0;
2251                         }
2252                 }
2253         }
2254         return 0;
2255 }
2256
2257 static int
2258 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2259 {
2260         Sg_scatter_hold *schp = &srp->data;
2261
2262         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2263                                    num_read_xfer));
2264         if ((!outp) || (num_read_xfer <= 0))
2265                 return 0;
2266         if (schp->k_use_sg > 0) {
2267                 int k, num;
2268                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2269
2270                 for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2271                      ++k, ++sclp) {
2272                         num = (int) sclp->length;
2273                         if (num > num_read_xfer) {
2274                                 if (__copy_to_user
2275                                     (outp, sg_scatg2virt(sclp), num_read_xfer))
2276                                         return -EFAULT;
2277                                 break;
2278                         } else {
2279                                 if (__copy_to_user
2280                                     (outp, sg_scatg2virt(sclp), num))
2281                                         return -EFAULT;
2282                                 num_read_xfer -= num;
2283                                 if (num_read_xfer <= 0)
2284                                         break;
2285                                 outp += num;
2286                         }
2287                 }
2288         } else {
2289                 if (__copy_to_user(outp, schp->buffer, num_read_xfer))
2290                         return -EFAULT;
2291         }
2292         return 0;
2293 }
2294
2295 static void
2296 sg_build_reserve(Sg_fd * sfp, int req_size)
2297 {
2298         Sg_scatter_hold *schp = &sfp->reserve;
2299
2300         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2301         do {
2302                 if (req_size < PAGE_SIZE)
2303                         req_size = PAGE_SIZE;
2304                 if (0 == sg_build_indirect(schp, sfp, req_size))
2305                         return;
2306                 else
2307                         sg_remove_scat(schp);
2308                 req_size >>= 1; /* divide by 2 */
2309         } while (req_size > (PAGE_SIZE / 2));
2310 }
2311
2312 static void
2313 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2314 {
2315         Sg_scatter_hold *req_schp = &srp->data;
2316         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2317
2318         srp->res_used = 1;
2319         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2320         size = (size + 1) & (~1);       /* round to even for aha1542 */
2321         if (rsv_schp->k_use_sg > 0) {
2322                 int k, num;
2323                 int rem = size;
2324                 struct scatterlist *sclp =
2325                     (struct scatterlist *) rsv_schp->buffer;
2326
2327                 for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
2328                         num = (int) sclp->length;
2329                         if (rem <= num) {
2330                                 if (0 == k) {
2331                                         req_schp->k_use_sg = 0;
2332                                         req_schp->buffer = sg_scatg2virt(sclp);
2333                                 } else {
2334                                         sfp->save_scat_len = num;
2335                                         sclp->length = (unsigned) rem;
2336                                         req_schp->k_use_sg = k + 1;
2337                                         req_schp->sglist_len =
2338                                             rsv_schp->sglist_len;
2339                                         req_schp->buffer = rsv_schp->buffer;
2340                                 }
2341                                 req_schp->bufflen = size;
2342                                 req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2343                                 break;
2344                         } else
2345                                 rem -= num;
2346                 }
2347                 if (k >= rsv_schp->k_use_sg)
2348                         SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2349         } else {
2350                 req_schp->k_use_sg = 0;
2351                 req_schp->bufflen = size;
2352                 req_schp->buffer = rsv_schp->buffer;
2353                 req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2354         }
2355 }
2356
2357 static void
2358 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2359 {
2360         Sg_scatter_hold *req_schp = &srp->data;
2361         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2362
2363         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2364                                    (int) req_schp->k_use_sg));
2365         if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2366                 struct scatterlist *sclp =
2367                     (struct scatterlist *) rsv_schp->buffer;
2368
2369                 if (sfp->save_scat_len > 0)
2370                         (sclp + (req_schp->k_use_sg - 1))->length =
2371                             (unsigned) sfp->save_scat_len;
2372                 else
2373                         SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2374         }
2375         req_schp->k_use_sg = 0;
2376         req_schp->bufflen = 0;
2377         req_schp->buffer = NULL;
2378         req_schp->sglist_len = 0;
2379         sfp->save_scat_len = 0;
2380         srp->res_used = 0;
2381 }
2382
2383 static Sg_request *
2384 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2385 {
2386         Sg_request *resp;
2387         unsigned long iflags;
2388
2389         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2390         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2391                 /* look for requests that are ready + not SG_IO owned */
2392                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2393                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2394                         resp->done = 2; /* guard against other readers */
2395                         break;
2396                 }
2397         }
2398         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2399         return resp;
2400 }
2401
2402 #ifdef CONFIG_SCSI_PROC_FS
2403 static Sg_request *
2404 sg_get_nth_request(Sg_fd * sfp, int nth)
2405 {
2406         Sg_request *resp;
2407         unsigned long iflags;
2408         int k;
2409
2410         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2411         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2412              ++k, resp = resp->nextrp) ;
2413         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2414         return resp;
2415 }
2416 #endif
2417
2418 /* always adds to end of list */
2419 static Sg_request *
2420 sg_add_request(Sg_fd * sfp)
2421 {
2422         int k;
2423         unsigned long iflags;
2424         Sg_request *resp;
2425         Sg_request *rp = sfp->req_arr;
2426
2427         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2428         resp = sfp->headrp;
2429         if (!resp) {
2430                 memset(rp, 0, sizeof (Sg_request));
2431                 rp->parentfp = sfp;
2432                 resp = rp;
2433                 sfp->headrp = resp;
2434         } else {
2435                 if (0 == sfp->cmd_q)
2436                         resp = NULL;    /* command queuing disallowed */
2437                 else {
2438                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2439                                 if (!rp->parentfp)
2440                                         break;
2441                         }
2442                         if (k < SG_MAX_QUEUE) {
2443                                 memset(rp, 0, sizeof (Sg_request));
2444                                 rp->parentfp = sfp;
2445                                 while (resp->nextrp)
2446                                         resp = resp->nextrp;
2447                                 resp->nextrp = rp;
2448                                 resp = rp;
2449                         } else
2450                                 resp = NULL;
2451                 }
2452         }
2453         if (resp) {
2454                 resp->nextrp = NULL;
2455                 resp->header.duration = jiffies_to_msecs(jiffies);
2456                 resp->my_cmdp = NULL;
2457         }
2458         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2459         return resp;
2460 }
2461
2462 /* Return of 1 for found; 0 for not found */
2463 static int
2464 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2465 {
2466         Sg_request *prev_rp;
2467         Sg_request *rp;
2468         unsigned long iflags;
2469         int res = 0;
2470
2471         if ((!sfp) || (!srp) || (!sfp->headrp))
2472                 return res;
2473         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2474         if (srp->my_cmdp)
2475                 srp->my_cmdp->upper_private_data = NULL;
2476         prev_rp = sfp->headrp;
2477         if (srp == prev_rp) {
2478                 sfp->headrp = prev_rp->nextrp;
2479                 prev_rp->parentfp = NULL;
2480                 res = 1;
2481         } else {
2482                 while ((rp = prev_rp->nextrp)) {
2483                         if (srp == rp) {
2484                                 prev_rp->nextrp = rp->nextrp;
2485                                 rp->parentfp = NULL;
2486                                 res = 1;
2487                                 break;
2488                         }
2489                         prev_rp = rp;
2490                 }
2491         }
2492         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2493         return res;
2494 }
2495
2496 #ifdef CONFIG_SCSI_PROC_FS
2497 static Sg_fd *
2498 sg_get_nth_sfp(Sg_device * sdp, int nth)
2499 {
2500         Sg_fd *resp;
2501         unsigned long iflags;
2502         int k;
2503
2504         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2505         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2506              ++k, resp = resp->nextfp) ;
2507         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2508         return resp;
2509 }
2510 #endif
2511
2512 static Sg_fd *
2513 sg_add_sfp(Sg_device * sdp, int dev)
2514 {
2515         Sg_fd *sfp;
2516         unsigned long iflags;
2517
2518         sfp = (Sg_fd *) sg_page_malloc(sizeof (Sg_fd), 0, NULL);
2519         if (!sfp)
2520                 return NULL;
2521         memset(sfp, 0, sizeof (Sg_fd));
2522         init_waitqueue_head(&sfp->read_wait);
2523         rwlock_init(&sfp->rq_list_lock);
2524
2525         sfp->timeout = SG_DEFAULT_TIMEOUT;
2526         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2527         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2528         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2529             sdp->device->host->unchecked_isa_dma : 1;
2530         sfp->cmd_q = SG_DEF_COMMAND_Q;
2531         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2532         sfp->parentdp = sdp;
2533         write_lock_irqsave(&sg_dev_arr_lock, iflags);
2534         if (!sdp->headfp)
2535                 sdp->headfp = sfp;
2536         else {                  /* add to tail of existing list */
2537                 Sg_fd *pfp = sdp->headfp;
2538                 while (pfp->nextfp)
2539                         pfp = pfp->nextfp;
2540                 pfp->nextfp = sfp;
2541         }
2542         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2543         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2544         sg_build_reserve(sfp, sg_big_buff);
2545         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2546                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2547         return sfp;
2548 }
2549
2550 static void
2551 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2552 {
2553         Sg_fd *fp;
2554         Sg_fd *prev_fp;
2555
2556         prev_fp = sdp->headfp;
2557         if (sfp == prev_fp)
2558                 sdp->headfp = prev_fp->nextfp;
2559         else {
2560                 while ((fp = prev_fp->nextfp)) {
2561                         if (sfp == fp) {
2562                                 prev_fp->nextfp = fp->nextfp;
2563                                 break;
2564                         }
2565                         prev_fp = fp;
2566                 }
2567         }
2568         if (sfp->reserve.bufflen > 0) {
2569                 SCSI_LOG_TIMEOUT(6, 
2570                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2571                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2572                 if (sfp->mmap_called)
2573                         sg_rb_correct4mmap(&sfp->reserve, 0);   /* undo correction */
2574                 sg_remove_scat(&sfp->reserve);
2575         }
2576         sfp->parentdp = NULL;
2577         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2578         sg_page_free((char *) sfp, sizeof (Sg_fd));
2579 }
2580
2581 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2582 static int
2583 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2584 {
2585         Sg_request *srp;
2586         Sg_request *tsrp;
2587         int dirty = 0;
2588         int res = 0;
2589
2590         for (srp = sfp->headrp; srp; srp = tsrp) {
2591                 tsrp = srp->nextrp;
2592                 if (sg_srp_done(srp, sfp))
2593                         sg_finish_rem_req(srp);
2594                 else
2595                         ++dirty;
2596         }
2597         if (0 == dirty) {
2598                 unsigned long iflags;
2599
2600                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
2601                 __sg_remove_sfp(sdp, sfp);
2602                 if (sdp->detached && (NULL == sdp->headfp)) {
2603                         int k, maxd;
2604
2605                         maxd = sg_dev_max;
2606                         for (k = 0; k < maxd; ++k) {
2607                                 if (sdp == sg_dev_arr[k])
2608                                         break;
2609                         }
2610                         if (k < maxd)
2611                                 sg_dev_arr[k] = NULL;
2612                         kfree((char *) sdp);
2613                         res = 1;
2614                 }
2615                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2616         } else {
2617                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2618                 /* only bump the access_count if we actually succeeded in
2619                  * throwing another counter on the host module */
2620                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */      
2621                 sfp->closed = 1;        /* flag dirty state on this fd */
2622                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2623                                   dirty));
2624         }
2625         return res;
2626 }
2627
2628 static int
2629 sg_res_in_use(Sg_fd * sfp)
2630 {
2631         const Sg_request *srp;
2632         unsigned long iflags;
2633
2634         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2635         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2636                 if (srp->res_used)
2637                         break;
2638         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2639         return srp ? 1 : 0;
2640 }
2641
2642 /* If retSzp==NULL want exact size or fail */
2643 static char *
2644 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2645 {
2646         char *resp = NULL;
2647         gfp_t page_mask;
2648         int order, a_size;
2649         int resSz = rqSz;
2650
2651         if (rqSz <= 0)
2652                 return resp;
2653
2654         if (lowDma)
2655                 page_mask = GFP_ATOMIC | GFP_DMA | __GFP_NOWARN;
2656         else
2657                 page_mask = GFP_ATOMIC | __GFP_NOWARN;
2658
2659         for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2660              order++, a_size <<= 1) ;
2661         resp = (char *) __get_free_pages(page_mask, order);
2662         while ((!resp) && order && retSzp) {
2663                 --order;
2664                 a_size >>= 1;   /* divide by 2, until PAGE_SIZE */
2665                 resp = (char *) __get_free_pages(page_mask, order);     /* try half */
2666                 resSz = a_size;
2667         }
2668         if (resp) {
2669                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2670                         memset(resp, 0, resSz);
2671                 if (retSzp)
2672                         *retSzp = resSz;
2673         }
2674         return resp;
2675 }
2676
2677 static void
2678 sg_page_free(char *buff, int size)
2679 {
2680         int order, a_size;
2681
2682         if (!buff)
2683                 return;
2684         for (order = 0, a_size = PAGE_SIZE; a_size < size;
2685              order++, a_size <<= 1) ;
2686         free_pages((unsigned long) buff, order);
2687 }
2688
2689 #ifndef MAINTENANCE_IN_CMD
2690 #define MAINTENANCE_IN_CMD 0xa3
2691 #endif
2692
2693 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2694         INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2695         READ_16, MODE_SENSE, MODE_SENSE_10, LOG_SENSE, REPORT_LUNS,
2696         SERVICE_ACTION_IN, RECEIVE_DIAGNOSTIC, READ_LONG, MAINTENANCE_IN_CMD
2697 };
2698
2699 static int
2700 sg_allow_access(unsigned char opcode, char dev_type)
2701 {
2702         int k;
2703
2704         if (TYPE_SCANNER == dev_type)   /* TYPE_ROM maybe burner */
2705                 return 1;
2706         for (k = 0; k < sizeof (allow_ops); ++k) {
2707                 if (opcode == allow_ops[k])
2708                         return 1;
2709         }
2710         return 0;
2711 }
2712
2713 #ifdef CONFIG_SCSI_PROC_FS
2714 static int
2715 sg_last_dev(void)
2716 {
2717         int k;
2718         unsigned long iflags;
2719
2720         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2721         for (k = sg_dev_max - 1; k >= 0; --k)
2722                 if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2723                         break;
2724         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2725         return k + 1;           /* origin 1 */
2726 }
2727 #endif
2728
2729 static Sg_device *
2730 sg_get_dev(int dev)
2731 {
2732         Sg_device *sdp = NULL;
2733         unsigned long iflags;
2734
2735         if (sg_dev_arr && (dev >= 0)) {
2736                 read_lock_irqsave(&sg_dev_arr_lock, iflags);
2737                 if (dev < sg_dev_max)
2738                         sdp = sg_dev_arr[dev];
2739                 read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2740         }
2741         return sdp;
2742 }
2743
2744 #ifdef CONFIG_SCSI_PROC_FS
2745
2746 static struct proc_dir_entry *sg_proc_sgp = NULL;
2747
2748 static char sg_proc_sg_dirname[] = "scsi/sg";
2749
2750 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2751
2752 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2753 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2754                                   size_t count, loff_t *off);
2755 static struct file_operations adio_fops = {
2756         /* .owner, .read and .llseek added in sg_proc_init() */
2757         .open = sg_proc_single_open_adio,
2758         .write = sg_proc_write_adio,
2759         .release = single_release,
2760 };
2761
2762 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2763 static ssize_t sg_proc_write_dressz(struct file *filp, 
2764                 const char __user *buffer, size_t count, loff_t *off);
2765 static struct file_operations dressz_fops = {
2766         .open = sg_proc_single_open_dressz,
2767         .write = sg_proc_write_dressz,
2768         .release = single_release,
2769 };
2770
2771 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2772 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2773 static struct file_operations version_fops = {
2774         .open = sg_proc_single_open_version,
2775         .release = single_release,
2776 };
2777
2778 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2779 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2780 static struct file_operations devhdr_fops = {
2781         .open = sg_proc_single_open_devhdr,
2782         .release = single_release,
2783 };
2784
2785 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2786 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2787 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2788 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2789 static void dev_seq_stop(struct seq_file *s, void *v);
2790 static struct file_operations dev_fops = {
2791         .open = sg_proc_open_dev,
2792         .release = seq_release,
2793 };
2794 static struct seq_operations dev_seq_ops = {
2795         .start = dev_seq_start,
2796         .next  = dev_seq_next,
2797         .stop  = dev_seq_stop,
2798         .show  = sg_proc_seq_show_dev,
2799 };
2800
2801 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2802 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2803 static struct file_operations devstrs_fops = {
2804         .open = sg_proc_open_devstrs,
2805         .release = seq_release,
2806 };
2807 static struct seq_operations devstrs_seq_ops = {
2808         .start = dev_seq_start,
2809         .next  = dev_seq_next,
2810         .stop  = dev_seq_stop,
2811         .show  = sg_proc_seq_show_devstrs,
2812 };
2813
2814 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2815 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2816 static struct file_operations debug_fops = {
2817         .open = sg_proc_open_debug,
2818         .release = seq_release,
2819 };
2820 static struct seq_operations debug_seq_ops = {
2821         .start = dev_seq_start,
2822         .next  = dev_seq_next,
2823         .stop  = dev_seq_stop,
2824         .show  = sg_proc_seq_show_debug,
2825 };
2826
2827
2828 struct sg_proc_leaf {
2829         const char * name;
2830         struct file_operations * fops;
2831 };
2832
2833 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2834         {"allow_dio", &adio_fops},
2835         {"debug", &debug_fops},
2836         {"def_reserved_size", &dressz_fops},
2837         {"device_hdr", &devhdr_fops},
2838         {"devices", &dev_fops},
2839         {"device_strs", &devstrs_fops},
2840         {"version", &version_fops}
2841 };
2842
2843 static int
2844 sg_proc_init(void)
2845 {
2846         int k, mask;
2847         int num_leaves =
2848             sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2849         struct proc_dir_entry *pdep;
2850         struct sg_proc_leaf * leaf;
2851
2852         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2853         if (!sg_proc_sgp)
2854                 return 1;
2855         for (k = 0; k < num_leaves; ++k) {
2856                 leaf = &sg_proc_leaf_arr[k];
2857                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2858                 pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2859                 if (pdep) {
2860                         leaf->fops->owner = THIS_MODULE,
2861                         leaf->fops->read = seq_read,
2862                         leaf->fops->llseek = seq_lseek,
2863                         pdep->proc_fops = leaf->fops;
2864                 }
2865         }
2866         return 0;
2867 }
2868
2869 static void
2870 sg_proc_cleanup(void)
2871 {
2872         int k;
2873         int num_leaves =
2874             sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2875
2876         if (!sg_proc_sgp)
2877                 return;
2878         for (k = 0; k < num_leaves; ++k)
2879                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2880         remove_proc_entry(sg_proc_sg_dirname, NULL);
2881 }
2882
2883
2884 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2885 {
2886         seq_printf(s, "%d\n", *((int *)s->private));
2887         return 0;
2888 }
2889
2890 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2891 {
2892         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2893 }
2894
2895 static ssize_t 
2896 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2897                    size_t count, loff_t *off)
2898 {
2899         int num;
2900         char buff[11];
2901
2902         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2903                 return -EACCES;
2904         num = (count < 10) ? count : 10;
2905         if (copy_from_user(buff, buffer, num))
2906                 return -EFAULT;
2907         buff[num] = '\0';
2908         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2909         return count;
2910 }
2911
2912 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2913 {
2914         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2915 }
2916
2917 static ssize_t 
2918 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2919                      size_t count, loff_t *off)
2920 {
2921         int num;
2922         unsigned long k = ULONG_MAX;
2923         char buff[11];
2924
2925         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2926                 return -EACCES;
2927         num = (count < 10) ? count : 10;
2928         if (copy_from_user(buff, buffer, num))
2929                 return -EFAULT;
2930         buff[num] = '\0';
2931         k = simple_strtoul(buff, NULL, 10);
2932         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2933                 sg_big_buff = k;
2934                 return count;
2935         }
2936         return -ERANGE;
2937 }
2938
2939 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2940 {
2941         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2942                    sg_version_date);
2943         return 0;
2944 }
2945
2946 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2947 {
2948         return single_open(file, sg_proc_seq_show_version, NULL);
2949 }
2950
2951 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2952 {
2953         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2954                    "online\n");
2955         return 0;
2956 }
2957
2958 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2959 {
2960         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2961 }
2962
2963 struct sg_proc_deviter {
2964         loff_t  index;
2965         size_t  max;
2966 };
2967
2968 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2969 {
2970         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2971
2972         s->private = it;
2973         if (! it)
2974                 return NULL;
2975
2976         if (NULL == sg_dev_arr)
2977                 return NULL;
2978         it->index = *pos;
2979         it->max = sg_last_dev();
2980         if (it->index >= it->max)
2981                 return NULL;
2982         return it;
2983 }
2984
2985 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2986 {
2987         struct sg_proc_deviter * it = s->private;
2988
2989         *pos = ++it->index;
2990         return (it->index < it->max) ? it : NULL;
2991 }
2992
2993 static void dev_seq_stop(struct seq_file *s, void *v)
2994 {
2995         kfree(s->private);
2996 }
2997
2998 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2999 {
3000         return seq_open(file, &dev_seq_ops);
3001 }
3002
3003 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
3004 {
3005         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
3006         Sg_device *sdp;
3007         struct scsi_device *scsidp;
3008
3009         sdp = it ? sg_get_dev(it->index) : NULL;
3010         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
3011                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
3012                               scsidp->host->host_no, scsidp->channel,
3013                               scsidp->id, scsidp->lun, (int) scsidp->type,
3014                               1,
3015                               (int) scsidp->queue_depth,
3016                               (int) scsidp->device_busy,
3017                               (int) scsi_device_online(scsidp));
3018         else
3019                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
3020         return 0;
3021 }
3022
3023 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
3024 {
3025         return seq_open(file, &devstrs_seq_ops);
3026 }
3027
3028 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
3029 {
3030         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
3031         Sg_device *sdp;
3032         struct scsi_device *scsidp;
3033
3034         sdp = it ? sg_get_dev(it->index) : NULL;
3035         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
3036                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
3037                            scsidp->vendor, scsidp->model, scsidp->rev);
3038         else
3039                 seq_printf(s, "<no active device>\n");
3040         return 0;
3041 }
3042
3043 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
3044 {
3045         int k, m, new_interface, blen, usg;
3046         Sg_request *srp;
3047         Sg_fd *fp;
3048         const sg_io_hdr_t *hp;
3049         const char * cp;
3050         unsigned int ms;
3051
3052         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
3053                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
3054                            "(res)sgat=%d low_dma=%d\n", k + 1,
3055                            jiffies_to_msecs(fp->timeout),
3056                            fp->reserve.bufflen,
3057                            (int) fp->reserve.k_use_sg,
3058                            (int) fp->low_dma);
3059                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
3060                            (int) fp->cmd_q, (int) fp->force_packid,
3061                            (int) fp->keep_orphan, (int) fp->closed);
3062                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
3063                         hp = &srp->header;
3064                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
3065                         if (srp->res_used) {
3066                                 if (new_interface && 
3067                                     (SG_FLAG_MMAP_IO & hp->flags))
3068                                         cp = "     mmap>> ";
3069                                 else
3070                                         cp = "     rb>> ";
3071                         } else {
3072                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
3073                                         cp = "     dio>> ";
3074                                 else
3075                                         cp = "     ";
3076                         }
3077                         seq_printf(s, cp);
3078                         blen = srp->my_cmdp ? 
3079                                 srp->my_cmdp->sr_bufflen : srp->data.bufflen;
3080                         usg = srp->my_cmdp ? 
3081                                 srp->my_cmdp->sr_use_sg : srp->data.k_use_sg;
3082                         seq_printf(s, srp->done ? 
3083                                    ((1 == srp->done) ?  "rcv:" : "fin:")
3084                                    : (srp->my_cmdp ? "act:" : "prior:"));
3085                         seq_printf(s, " id=%d blen=%d",
3086                                    srp->header.pack_id, blen);
3087                         if (srp->done)
3088                                 seq_printf(s, " dur=%d", hp->duration);
3089                         else {
3090                                 ms = jiffies_to_msecs(jiffies);
3091                                 seq_printf(s, " t_o/elap=%d/%d",
3092                                         (new_interface ? hp->timeout :
3093                                                   jiffies_to_msecs(fp->timeout)),
3094                                         (ms > hp->duration ? ms - hp->duration : 0));
3095                         }
3096                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
3097                                    (int) srp->data.cmd_opcode);
3098                 }
3099                 if (0 == m)
3100                         seq_printf(s, "     No requests active\n");
3101         }
3102 }
3103
3104 static int sg_proc_open_debug(struct inode *inode, struct file *file)
3105 {
3106         return seq_open(file, &debug_seq_ops);
3107 }
3108
3109 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
3110 {
3111         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
3112         Sg_device *sdp;
3113
3114         if (it && (0 == it->index)) {
3115                 seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
3116                            "(origin 1)\n", sg_dev_max, (int)it->max);
3117                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
3118         }
3119         sdp = it ? sg_get_dev(it->index) : NULL;
3120         if (sdp) {
3121                 struct scsi_device *scsidp = sdp->device;
3122
3123                 if (NULL == scsidp) {
3124                         seq_printf(s, "device %d detached ??\n", 
3125                                    (int)it->index);
3126                         return 0;
3127                 }
3128
3129                 if (sg_get_nth_sfp(sdp, 0)) {
3130                         seq_printf(s, " >>> device=%s ",
3131                                 sdp->disk->disk_name);
3132                         if (sdp->detached)
3133                                 seq_printf(s, "detached pending close ");
3134                         else
3135                                 seq_printf
3136                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
3137                                      scsidp->host->host_no,
3138                                      scsidp->channel, scsidp->id,
3139                                      scsidp->lun,
3140                                      scsidp->host->hostt->emulated);
3141                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
3142                                    sdp->sg_tablesize, sdp->exclude);
3143                 }
3144                 sg_proc_debug_helper(s, sdp);
3145         }
3146         return 0;
3147 }
3148
3149 #endif                          /* CONFIG_SCSI_PROC_FS */
3150
3151 module_init(init_sg);
3152 module_exit(exit_sg);
3153 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);