[PATCH] irq-flags: drivers/char: Use the new IRQF_ constants
[linux-3.10.git] / drivers / char / snsc.c
1 /*
2  * SN Platform system controller communication support
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file "COPYING" in the main directory of this archive
6  * for more details.
7  *
8  * Copyright (C) 2004, 2006 Silicon Graphics, Inc. All rights reserved.
9  */
10
11 /*
12  * System controller communication driver
13  *
14  * This driver allows a user process to communicate with the system
15  * controller (a.k.a. "IRouter") network in an SGI SN system.
16  */
17
18 #include <linux/interrupt.h>
19 #include <linux/sched.h>
20 #include <linux/device.h>
21 #include <linux/poll.h>
22 #include <linux/module.h>
23 #include <linux/slab.h>
24 #include <asm/sn/io.h>
25 #include <asm/sn/sn_sal.h>
26 #include <asm/sn/module.h>
27 #include <asm/sn/geo.h>
28 #include <asm/sn/nodepda.h>
29 #include "snsc.h"
30
31 #define SYSCTL_BASENAME "snsc"
32
33 #define SCDRV_BUFSZ     2048
34 #define SCDRV_TIMEOUT   1000
35
36 static irqreturn_t
37 scdrv_interrupt(int irq, void *subch_data, struct pt_regs *regs)
38 {
39         struct subch_data_s *sd = subch_data;
40         unsigned long flags;
41         int status;
42
43         spin_lock_irqsave(&sd->sd_rlock, flags);
44         spin_lock(&sd->sd_wlock);
45         status = ia64_sn_irtr_intr(sd->sd_nasid, sd->sd_subch);
46
47         if (status > 0) {
48                 if (status & SAL_IROUTER_INTR_RECV) {
49                         wake_up(&sd->sd_rq);
50                 }
51                 if (status & SAL_IROUTER_INTR_XMIT) {
52                         ia64_sn_irtr_intr_disable
53                             (sd->sd_nasid, sd->sd_subch,
54                              SAL_IROUTER_INTR_XMIT);
55                         wake_up(&sd->sd_wq);
56                 }
57         }
58         spin_unlock(&sd->sd_wlock);
59         spin_unlock_irqrestore(&sd->sd_rlock, flags);
60         return IRQ_HANDLED;
61 }
62
63 /*
64  * scdrv_open
65  *
66  * Reserve a subchannel for system controller communication.
67  */
68
69 static int
70 scdrv_open(struct inode *inode, struct file *file)
71 {
72         struct sysctl_data_s *scd;
73         struct subch_data_s *sd;
74         int rv;
75
76         /* look up device info for this device file */
77         scd = container_of(inode->i_cdev, struct sysctl_data_s, scd_cdev);
78
79         /* allocate memory for subchannel data */
80         sd = kzalloc(sizeof (struct subch_data_s), GFP_KERNEL);
81         if (sd == NULL) {
82                 printk("%s: couldn't allocate subchannel data\n",
83                        __FUNCTION__);
84                 return -ENOMEM;
85         }
86
87         /* initialize subch_data_s fields */
88         sd->sd_nasid = scd->scd_nasid;
89         sd->sd_subch = ia64_sn_irtr_open(scd->scd_nasid);
90
91         if (sd->sd_subch < 0) {
92                 kfree(sd);
93                 printk("%s: couldn't allocate subchannel\n", __FUNCTION__);
94                 return -EBUSY;
95         }
96
97         spin_lock_init(&sd->sd_rlock);
98         spin_lock_init(&sd->sd_wlock);
99         init_waitqueue_head(&sd->sd_rq);
100         init_waitqueue_head(&sd->sd_wq);
101         sema_init(&sd->sd_rbs, 1);
102         sema_init(&sd->sd_wbs, 1);
103
104         file->private_data = sd;
105
106         /* hook this subchannel up to the system controller interrupt */
107         rv = request_irq(SGI_UART_VECTOR, scdrv_interrupt,
108                          IRQF_SHARED | IRQF_DISABLED,
109                          SYSCTL_BASENAME, sd);
110         if (rv) {
111                 ia64_sn_irtr_close(sd->sd_nasid, sd->sd_subch);
112                 kfree(sd);
113                 printk("%s: irq request failed (%d)\n", __FUNCTION__, rv);
114                 return -EBUSY;
115         }
116
117         return 0;
118 }
119
120 /*
121  * scdrv_release
122  *
123  * Release a previously-reserved subchannel.
124  */
125
126 static int
127 scdrv_release(struct inode *inode, struct file *file)
128 {
129         struct subch_data_s *sd = (struct subch_data_s *) file->private_data;
130         int rv;
131
132         /* free the interrupt */
133         free_irq(SGI_UART_VECTOR, sd);
134
135         /* ask SAL to close the subchannel */
136         rv = ia64_sn_irtr_close(sd->sd_nasid, sd->sd_subch);
137
138         kfree(sd);
139         return rv;
140 }
141
142 /*
143  * scdrv_read
144  *
145  * Called to read bytes from the open IRouter pipe.
146  *
147  */
148
149 static inline int
150 read_status_check(struct subch_data_s *sd, int *len)
151 {
152         return ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch, sd->sd_rb, len);
153 }
154
155 static ssize_t
156 scdrv_read(struct file *file, char __user *buf, size_t count, loff_t *f_pos)
157 {
158         int status;
159         int len;
160         unsigned long flags;
161         struct subch_data_s *sd = (struct subch_data_s *) file->private_data;
162
163         /* try to get control of the read buffer */
164         if (down_trylock(&sd->sd_rbs)) {
165                 /* somebody else has it now;
166                  * if we're non-blocking, then exit...
167                  */
168                 if (file->f_flags & O_NONBLOCK) {
169                         return -EAGAIN;
170                 }
171                 /* ...or if we want to block, then do so here */
172                 if (down_interruptible(&sd->sd_rbs)) {
173                         /* something went wrong with wait */
174                         return -ERESTARTSYS;
175                 }
176         }
177
178         /* anything to read? */
179         len = CHUNKSIZE;
180         spin_lock_irqsave(&sd->sd_rlock, flags);
181         status = read_status_check(sd, &len);
182
183         /* if not, and we're blocking I/O, loop */
184         while (status < 0) {
185                 DECLARE_WAITQUEUE(wait, current);
186
187                 if (file->f_flags & O_NONBLOCK) {
188                         spin_unlock_irqrestore(&sd->sd_rlock, flags);
189                         up(&sd->sd_rbs);
190                         return -EAGAIN;
191                 }
192
193                 len = CHUNKSIZE;
194                 set_current_state(TASK_INTERRUPTIBLE);
195                 add_wait_queue(&sd->sd_rq, &wait);
196                 spin_unlock_irqrestore(&sd->sd_rlock, flags);
197
198                 schedule_timeout(SCDRV_TIMEOUT);
199
200                 remove_wait_queue(&sd->sd_rq, &wait);
201                 if (signal_pending(current)) {
202                         /* wait was interrupted */
203                         up(&sd->sd_rbs);
204                         return -ERESTARTSYS;
205                 }
206
207                 spin_lock_irqsave(&sd->sd_rlock, flags);
208                 status = read_status_check(sd, &len);
209         }
210         spin_unlock_irqrestore(&sd->sd_rlock, flags);
211
212         if (len > 0) {
213                 /* we read something in the last read_status_check(); copy
214                  * it out to user space
215                  */
216                 if (count < len) {
217                         pr_debug("%s: only accepting %d of %d bytes\n",
218                                  __FUNCTION__, (int) count, len);
219                 }
220                 len = min((int) count, len);
221                 if (copy_to_user(buf, sd->sd_rb, len))
222                         len = -EFAULT;
223         }
224
225         /* release the read buffer and wake anyone who might be
226          * waiting for it
227          */
228         up(&sd->sd_rbs);
229
230         /* return the number of characters read in */
231         return len;
232 }
233
234 /*
235  * scdrv_write
236  *
237  * Writes a chunk of an IRouter packet (or other system controller data)
238  * to the system controller.
239  *
240  */
241 static inline int
242 write_status_check(struct subch_data_s *sd, int count)
243 {
244         return ia64_sn_irtr_send(sd->sd_nasid, sd->sd_subch, sd->sd_wb, count);
245 }
246
247 static ssize_t
248 scdrv_write(struct file *file, const char __user *buf,
249             size_t count, loff_t *f_pos)
250 {
251         unsigned long flags;
252         int status;
253         struct subch_data_s *sd = (struct subch_data_s *) file->private_data;
254
255         /* try to get control of the write buffer */
256         if (down_trylock(&sd->sd_wbs)) {
257                 /* somebody else has it now;
258                  * if we're non-blocking, then exit...
259                  */
260                 if (file->f_flags & O_NONBLOCK) {
261                         return -EAGAIN;
262                 }
263                 /* ...or if we want to block, then do so here */
264                 if (down_interruptible(&sd->sd_wbs)) {
265                         /* something went wrong with wait */
266                         return -ERESTARTSYS;
267                 }
268         }
269
270         count = min((int) count, CHUNKSIZE);
271         if (copy_from_user(sd->sd_wb, buf, count)) {
272                 up(&sd->sd_wbs);
273                 return -EFAULT;
274         }
275
276         /* try to send the buffer */
277         spin_lock_irqsave(&sd->sd_wlock, flags);
278         status = write_status_check(sd, count);
279
280         /* if we failed, and we want to block, then loop */
281         while (status <= 0) {
282                 DECLARE_WAITQUEUE(wait, current);
283
284                 if (file->f_flags & O_NONBLOCK) {
285                         spin_unlock(&sd->sd_wlock);
286                         up(&sd->sd_wbs);
287                         return -EAGAIN;
288                 }
289
290                 set_current_state(TASK_INTERRUPTIBLE);
291                 add_wait_queue(&sd->sd_wq, &wait);
292                 spin_unlock_irqrestore(&sd->sd_wlock, flags);
293
294                 schedule_timeout(SCDRV_TIMEOUT);
295
296                 remove_wait_queue(&sd->sd_wq, &wait);
297                 if (signal_pending(current)) {
298                         /* wait was interrupted */
299                         up(&sd->sd_wbs);
300                         return -ERESTARTSYS;
301                 }
302
303                 spin_lock_irqsave(&sd->sd_wlock, flags);
304                 status = write_status_check(sd, count);
305         }
306         spin_unlock_irqrestore(&sd->sd_wlock, flags);
307
308         /* release the write buffer and wake anyone who's waiting for it */
309         up(&sd->sd_wbs);
310
311         /* return the number of characters accepted (should be the complete
312          * "chunk" as requested)
313          */
314         if ((status >= 0) && (status < count)) {
315                 pr_debug("Didn't accept the full chunk; %d of %d\n",
316                          status, (int) count);
317         }
318         return status;
319 }
320
321 static unsigned int
322 scdrv_poll(struct file *file, struct poll_table_struct *wait)
323 {
324         unsigned int mask = 0;
325         int status = 0;
326         struct subch_data_s *sd = (struct subch_data_s *) file->private_data;
327         unsigned long flags;
328
329         poll_wait(file, &sd->sd_rq, wait);
330         poll_wait(file, &sd->sd_wq, wait);
331
332         spin_lock_irqsave(&sd->sd_rlock, flags);
333         spin_lock(&sd->sd_wlock);
334         status = ia64_sn_irtr_intr(sd->sd_nasid, sd->sd_subch);
335         spin_unlock(&sd->sd_wlock);
336         spin_unlock_irqrestore(&sd->sd_rlock, flags);
337
338         if (status > 0) {
339                 if (status & SAL_IROUTER_INTR_RECV) {
340                         mask |= POLLIN | POLLRDNORM;
341                 }
342                 if (status & SAL_IROUTER_INTR_XMIT) {
343                         mask |= POLLOUT | POLLWRNORM;
344                 }
345         }
346
347         return mask;
348 }
349
350 static struct file_operations scdrv_fops = {
351         .owner =        THIS_MODULE,
352         .read =         scdrv_read,
353         .write =        scdrv_write,
354         .poll =         scdrv_poll,
355         .open =         scdrv_open,
356         .release =      scdrv_release,
357 };
358
359 static struct class *snsc_class;
360
361 /*
362  * scdrv_init
363  *
364  * Called at boot time to initialize the system controller communication
365  * facility.
366  */
367 int __init
368 scdrv_init(void)
369 {
370         geoid_t geoid;
371         cnodeid_t cnode;
372         char devname[32];
373         char *devnamep;
374         struct sysctl_data_s *scd;
375         void *salbuf;
376         dev_t first_dev, dev;
377         nasid_t event_nasid = ia64_sn_get_console_nasid();
378
379         if (alloc_chrdev_region(&first_dev, 0, num_cnodes,
380                                 SYSCTL_BASENAME) < 0) {
381                 printk("%s: failed to register SN system controller device\n",
382                        __FUNCTION__);
383                 return -ENODEV;
384         }
385         snsc_class = class_create(THIS_MODULE, SYSCTL_BASENAME);
386
387         for (cnode = 0; cnode < num_cnodes; cnode++) {
388                         geoid = cnodeid_get_geoid(cnode);
389                         devnamep = devname;
390                         format_module_id(devnamep, geo_module(geoid),
391                                          MODULE_FORMAT_BRIEF);
392                         devnamep = devname + strlen(devname);
393                         sprintf(devnamep, "^%d#%d", geo_slot(geoid),
394                                 geo_slab(geoid));
395
396                         /* allocate sysctl device data */
397                         scd = kzalloc(sizeof (struct sysctl_data_s),
398                                       GFP_KERNEL);
399                         if (!scd) {
400                                 printk("%s: failed to allocate device info"
401                                        "for %s/%s\n", __FUNCTION__,
402                                        SYSCTL_BASENAME, devname);
403                                 continue;
404                         }
405
406                         /* initialize sysctl device data fields */
407                         scd->scd_nasid = cnodeid_to_nasid(cnode);
408                         if (!(salbuf = kmalloc(SCDRV_BUFSZ, GFP_KERNEL))) {
409                                 printk("%s: failed to allocate driver buffer"
410                                        "(%s%s)\n", __FUNCTION__,
411                                        SYSCTL_BASENAME, devname);
412                                 kfree(scd);
413                                 continue;
414                         }
415
416                         if (ia64_sn_irtr_init(scd->scd_nasid, salbuf,
417                                               SCDRV_BUFSZ) < 0) {
418                                 printk
419                                     ("%s: failed to initialize SAL for"
420                                      " system controller communication"
421                                      " (%s/%s): outdated PROM?\n",
422                                      __FUNCTION__, SYSCTL_BASENAME, devname);
423                                 kfree(scd);
424                                 kfree(salbuf);
425                                 continue;
426                         }
427
428                         dev = first_dev + cnode;
429                         cdev_init(&scd->scd_cdev, &scdrv_fops);
430                         if (cdev_add(&scd->scd_cdev, dev, 1)) {
431                                 printk("%s: failed to register system"
432                                        " controller device (%s%s)\n",
433                                        __FUNCTION__, SYSCTL_BASENAME, devname);
434                                 kfree(scd);
435                                 kfree(salbuf);
436                                 continue;
437                         }
438
439                         class_device_create(snsc_class, NULL, dev, NULL,
440                                                 "%s", devname);
441
442                         ia64_sn_irtr_intr_enable(scd->scd_nasid,
443                                                  0 /*ignored */ ,
444                                                  SAL_IROUTER_INTR_RECV);
445
446                         /* on the console nasid, prepare to receive
447                          * system controller environmental events
448                          */
449                         if(scd->scd_nasid == event_nasid) {
450                                 scdrv_event_init(scd);
451                         }
452         }
453         return 0;
454 }
455
456 module_init(scdrv_init);