Linux-2.6.12-rc2
[linux-3.10.git] / arch / s390 / mm / extmem.c
1 /*
2  * File...........: arch/s390/mm/extmem.c
3  * Author(s)......: Carsten Otte <cotte@de.ibm.com>
4  *                  Rob M van der Heij <rvdheij@nl.ibm.com>
5  *                  Steven Shultz <shultzss@us.ibm.com>
6  * Bugreports.to..: <Linux390@de.ibm.com>
7  * (C) IBM Corporation 2002-2004
8  */
9
10 #include <linux/kernel.h>
11 #include <linux/string.h>
12 #include <linux/spinlock.h>
13 #include <linux/list.h>
14 #include <linux/slab.h>
15 #include <linux/module.h>
16 #include <linux/bootmem.h>
17 #include <asm/page.h>
18 #include <asm/ebcdic.h>
19 #include <asm/errno.h>
20 #include <asm/extmem.h>
21 #include <asm/cpcmd.h>
22 #include <linux/ctype.h>
23
24 #define DCSS_DEBUG      /* Debug messages on/off */
25
26 #define DCSS_NAME "extmem"
27 #ifdef DCSS_DEBUG
28 #define PRINT_DEBUG(x...)       printk(KERN_DEBUG DCSS_NAME " debug:" x)
29 #else
30 #define PRINT_DEBUG(x...)   do {} while (0)
31 #endif
32 #define PRINT_INFO(x...)        printk(KERN_INFO DCSS_NAME " info:" x)
33 #define PRINT_WARN(x...)        printk(KERN_WARNING DCSS_NAME " warning:" x)
34 #define PRINT_ERR(x...)         printk(KERN_ERR DCSS_NAME " error:" x)
35
36
37 #define DCSS_LOADSHR    0x00
38 #define DCSS_LOADNSR    0x04
39 #define DCSS_PURGESEG   0x08
40 #define DCSS_FINDSEG    0x0c
41 #define DCSS_LOADNOLY   0x10
42 #define DCSS_SEGEXT     0x18
43 #define DCSS_FINDSEGA   0x0c
44
45 struct qrange {
46         unsigned int  start; // 3byte start address, 1 byte type
47         unsigned int  end;   // 3byte end address, 1 byte reserved
48 };
49
50 struct qout64 {
51         int segstart;
52         int segend;
53         int segcnt;
54         int segrcnt;
55         struct qrange range[6];
56 };
57
58 struct qin64 {
59         char qopcode;
60         char rsrv1[3];
61         char qrcode;
62         char rsrv2[3];
63         char qname[8];
64         unsigned int qoutptr;
65         short int qoutlen;
66 };
67
68 struct dcss_segment {
69         struct list_head list;
70         char dcss_name[8];
71         unsigned long start_addr;
72         unsigned long end;
73         atomic_t ref_count;
74         int do_nonshared;
75         unsigned int vm_segtype;
76         struct qrange range[6];
77         int segcnt;
78 };
79
80 static DEFINE_SPINLOCK(dcss_lock);
81 static struct list_head dcss_list = LIST_HEAD_INIT(dcss_list);
82 static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
83                                         "EW/EN-MIXED" };
84
85 extern struct {
86         unsigned long addr, size, type;
87 } memory_chunk[MEMORY_CHUNKS];
88
89 /*
90  * Create the 8 bytes, ebcdic VM segment name from
91  * an ascii name.
92  */
93 static void inline
94 dcss_mkname(char *name, char *dcss_name)
95 {
96         int i;
97
98         for (i = 0; i < 8; i++) {
99                 if (name[i] == '\0')
100                         break;
101                 dcss_name[i] = toupper(name[i]);
102         };
103         for (; i < 8; i++)
104                 dcss_name[i] = ' ';
105         ASCEBC(dcss_name, 8);
106 }
107
108
109 /*
110  * search all segments in dcss_list, and return the one
111  * namend *name. If not found, return NULL.
112  */
113 static struct dcss_segment *
114 segment_by_name (char *name)
115 {
116         char dcss_name[9];
117         struct list_head *l;
118         struct dcss_segment *tmp, *retval = NULL;
119
120         assert_spin_locked(&dcss_lock);
121         dcss_mkname (name, dcss_name);
122         list_for_each (l, &dcss_list) {
123                 tmp = list_entry (l, struct dcss_segment, list);
124                 if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
125                         retval = tmp;
126                         break;
127                 }
128         }
129         return retval;
130 }
131
132
133 /*
134  * Perform a function on a dcss segment.
135  */
136 static inline int
137 dcss_diag (__u8 func, void *parameter,
138            unsigned long *ret1, unsigned long *ret2)
139 {
140         unsigned long rx, ry;
141         int rc;
142
143         rx = (unsigned long) parameter;
144         ry = (unsigned long) func;
145         __asm__ __volatile__(
146 #ifdef CONFIG_ARCH_S390X
147                 "   sam31\n" // switch to 31 bit
148                 "   diag    %0,%1,0x64\n"
149                 "   sam64\n" // switch back to 64 bit
150 #else
151                 "   diag    %0,%1,0x64\n"
152 #endif
153                 "   ipm     %2\n"
154                 "   srl     %2,28\n"
155                 : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc" );
156         *ret1 = rx;
157         *ret2 = ry;
158         return rc;
159 }
160
161 static inline int
162 dcss_diag_translate_rc (int vm_rc) {
163         if (vm_rc == 44)
164                 return -ENOENT;
165         return -EIO;
166 }
167
168
169 /* do a diag to get info about a segment.
170  * fills start_address, end and vm_segtype fields
171  */
172 static int
173 query_segment_type (struct dcss_segment *seg)
174 {
175         struct qin64  *qin = kmalloc (sizeof(struct qin64), GFP_DMA);
176         struct qout64 *qout = kmalloc (sizeof(struct qout64), GFP_DMA);
177
178         int diag_cc, rc, i;
179         unsigned long dummy, vmrc;
180
181         if ((qin == NULL) || (qout == NULL)) {
182                 rc = -ENOMEM;
183                 goto out_free;
184         }
185
186         /* initialize diag input parameters */
187         qin->qopcode = DCSS_FINDSEGA;
188         qin->qoutptr = (unsigned long) qout;
189         qin->qoutlen = sizeof(struct qout64);
190         memcpy (qin->qname, seg->dcss_name, 8);
191
192         diag_cc = dcss_diag (DCSS_SEGEXT, qin, &dummy, &vmrc);
193
194         if (diag_cc > 1) {
195                 rc = dcss_diag_translate_rc (vmrc);
196                 goto out_free;
197         }
198
199         if (qout->segcnt > 6) {
200                 rc = -ENOTSUPP;
201                 goto out_free;
202         }
203
204         if (qout->segcnt == 1) {
205                 seg->vm_segtype = qout->range[0].start & 0xff;
206         } else {
207                 /* multi-part segment. only one type supported here:
208                     - all parts are contiguous
209                     - all parts are either EW or EN type
210                     - maximum 6 parts allowed */
211                 unsigned long start = qout->segstart >> PAGE_SHIFT;
212                 for (i=0; i<qout->segcnt; i++) {
213                         if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
214                             ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
215                                 rc = -ENOTSUPP;
216                                 goto out_free;
217                         }
218                         if (start != qout->range[i].start >> PAGE_SHIFT) {
219                                 rc = -ENOTSUPP;
220                                 goto out_free;
221                         }
222                         start = (qout->range[i].end >> PAGE_SHIFT) + 1;
223                 }
224                 seg->vm_segtype = SEG_TYPE_EWEN;
225         }
226
227         /* analyze diag output and update seg */
228         seg->start_addr = qout->segstart;
229         seg->end = qout->segend;
230
231         memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
232         seg->segcnt = qout->segcnt;
233
234         rc = 0;
235
236  out_free:
237         if (qin) kfree(qin);
238         if (qout) kfree(qout);
239         return rc;
240 }
241
242 /*
243  * check if the given segment collides with guest storage.
244  * returns 1 if this is the case, 0 if no collision was found
245  */
246 static int
247 segment_overlaps_storage(struct dcss_segment *seg)
248 {
249         int i;
250
251         for (i=0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
252                 if (memory_chunk[i].type != 0)
253                         continue;
254                 if ((memory_chunk[i].addr >> 20) > (seg->end >> 20))
255                         continue;
256                 if (((memory_chunk[i].addr + memory_chunk[i].size - 1) >> 20)
257                                 < (seg->start_addr >> 20))
258                         continue;
259                 return 1;
260         }
261         return 0;
262 }
263
264 /*
265  * check if segment collides with other segments that are currently loaded
266  * returns 1 if this is the case, 0 if no collision was found
267  */
268 static int
269 segment_overlaps_others (struct dcss_segment *seg)
270 {
271         struct list_head *l;
272         struct dcss_segment *tmp;
273
274         assert_spin_locked(&dcss_lock);
275         list_for_each(l, &dcss_list) {
276                 tmp = list_entry(l, struct dcss_segment, list);
277                 if ((tmp->start_addr >> 20) > (seg->end >> 20))
278                         continue;
279                 if ((tmp->end >> 20) < (seg->start_addr >> 20))
280                         continue;
281                 if (seg == tmp)
282                         continue;
283                 return 1;
284         }
285         return 0;
286 }
287
288 /*
289  * check if segment exceeds the kernel mapping range (detected or set via mem=)
290  * returns 1 if this is the case, 0 if segment fits into the range
291  */
292 static inline int
293 segment_exceeds_range (struct dcss_segment *seg)
294 {
295         int seg_last_pfn = (seg->end) >> PAGE_SHIFT;
296         if (seg_last_pfn > max_pfn)
297                 return 1;
298         return 0;
299 }
300
301 /*
302  * get info about a segment
303  * possible return values:
304  * -ENOSYS  : we are not running on VM
305  * -EIO     : could not perform query diagnose
306  * -ENOENT  : no such segment
307  * -ENOTSUPP: multi-part segment cannot be used with linux
308  * -ENOSPC  : segment cannot be used (overlaps with storage)
309  * -ENOMEM  : out of memory
310  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
311  */
312 int
313 segment_type (char* name)
314 {
315         int rc;
316         struct dcss_segment seg;
317
318         if (!MACHINE_IS_VM)
319                 return -ENOSYS;
320
321         dcss_mkname(name, seg.dcss_name);
322         rc = query_segment_type (&seg);
323         if (rc < 0)
324                 return rc;
325         return seg.vm_segtype;
326 }
327
328 /*
329  * real segment loading function, called from segment_load
330  */
331 static int
332 __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
333 {
334         struct dcss_segment *seg = kmalloc(sizeof(struct dcss_segment),
335                         GFP_DMA);
336         int dcss_command, rc, diag_cc;
337
338         if (seg == NULL) {
339                 rc = -ENOMEM;
340                 goto out;
341         }
342         dcss_mkname (name, seg->dcss_name);
343         rc = query_segment_type (seg);
344         if (rc < 0)
345                 goto out_free;
346         if (segment_exceeds_range(seg)) {
347                 PRINT_WARN ("segment_load: not loading segment %s - exceeds"
348                                 " kernel mapping range\n",name);
349                 rc = -ERANGE;
350                 goto out_free;
351         }
352         if (segment_overlaps_storage(seg)) {
353                 PRINT_WARN ("segment_load: not loading segment %s - overlaps"
354                                 " storage\n",name);
355                 rc = -ENOSPC;
356                 goto out_free;
357         }
358         if (segment_overlaps_others(seg)) {
359                 PRINT_WARN ("segment_load: not loading segment %s - overlaps"
360                                 " other segments\n",name);
361                 rc = -EBUSY;
362                 goto out_free;
363         }
364         if (do_nonshared)
365                 dcss_command = DCSS_LOADNSR;
366         else
367                 dcss_command = DCSS_LOADNOLY;
368
369         diag_cc = dcss_diag(dcss_command, seg->dcss_name,
370                         &seg->start_addr, &seg->end);
371         if (diag_cc > 1) {
372                 PRINT_WARN ("segment_load: could not load segment %s - "
373                                 "diag returned error (%ld)\n",name,seg->end);
374                 rc = dcss_diag_translate_rc (seg->end);
375                 dcss_diag(DCSS_PURGESEG, seg->dcss_name,
376                                 &seg->start_addr, &seg->end);
377                 goto out_free;
378         }
379         seg->do_nonshared = do_nonshared;
380         atomic_set(&seg->ref_count, 1);
381         list_add(&seg->list, &dcss_list);
382         rc = seg->vm_segtype;
383         *addr = seg->start_addr;
384         *end  = seg->end;
385         if (do_nonshared)
386                 PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
387                                 "type %s in non-shared mode\n", name,
388                                 (void*)seg->start_addr, (void*)seg->end,
389                                 segtype_string[seg->vm_segtype]);
390         else
391                 PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
392                                 "type %s in shared mode\n", name,
393                                 (void*)seg->start_addr, (void*)seg->end,
394                                 segtype_string[seg->vm_segtype]);
395         goto out;
396  out_free:
397         kfree (seg);
398  out:
399         return rc;
400 }
401
402 /*
403  * this function loads a DCSS segment
404  * name         : name of the DCSS
405  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
406  *                1 indicates that the dcss should be exclusive for this linux image
407  * addr         : will be filled with start address of the segment
408  * end          : will be filled with end address of the segment
409  * return values:
410  * -ENOSYS  : we are not running on VM
411  * -EIO     : could not perform query or load diagnose
412  * -ENOENT  : no such segment
413  * -ENOTSUPP: multi-part segment cannot be used with linux
414  * -ENOSPC  : segment cannot be used (overlaps with storage)
415  * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
416  * -ERANGE  : segment cannot be used (exceeds kernel mapping range)
417  * -EPERM   : segment is currently loaded with incompatible permissions
418  * -ENOMEM  : out of memory
419  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
420  */
421 int
422 segment_load (char *name, int do_nonshared, unsigned long *addr,
423                 unsigned long *end)
424 {
425         struct dcss_segment *seg;
426         int rc;
427
428         if (!MACHINE_IS_VM)
429                 return -ENOSYS;
430
431         spin_lock (&dcss_lock);
432         seg = segment_by_name (name);
433         if (seg == NULL)
434                 rc = __segment_load (name, do_nonshared, addr, end);
435         else {
436                 if (do_nonshared == seg->do_nonshared) {
437                         atomic_inc(&seg->ref_count);
438                         *addr = seg->start_addr;
439                         *end  = seg->end;
440                         rc    = seg->vm_segtype;
441                 } else {
442                         *addr = *end = 0;
443                         rc    = -EPERM;
444                 }
445         }
446         spin_unlock (&dcss_lock);
447         return rc;
448 }
449
450 /*
451  * this function modifies the shared state of a DCSS segment. note that
452  * name         : name of the DCSS
453  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
454  *                1 indicates that the dcss should be exclusive for this linux image
455  * return values:
456  * -EIO     : could not perform load diagnose (segment gone!)
457  * -ENOENT  : no such segment (segment gone!)
458  * -EAGAIN  : segment is in use by other exploiters, try later
459  * -EINVAL  : no segment with the given name is currently loaded - name invalid
460  * 0        : operation succeeded
461  */
462 int
463 segment_modify_shared (char *name, int do_nonshared)
464 {
465         struct dcss_segment *seg;
466         unsigned long dummy;
467         int dcss_command, rc, diag_cc;
468
469         spin_lock (&dcss_lock);
470         seg = segment_by_name (name);
471         if (seg == NULL) {
472                 rc = -EINVAL;
473                 goto out_unlock;
474         }
475         if (do_nonshared == seg->do_nonshared) {
476                 PRINT_INFO ("segment_modify_shared: not reloading segment %s"
477                                 " - already in requested mode\n",name);
478                 rc = 0;
479                 goto out_unlock;
480         }
481         if (atomic_read (&seg->ref_count) != 1) {
482                 PRINT_WARN ("segment_modify_shared: not reloading segment %s - "
483                                 "segment is in use by other driver(s)\n",name);
484                 rc = -EAGAIN;
485                 goto out_unlock;
486         }
487         dcss_diag(DCSS_PURGESEG, seg->dcss_name,
488                   &dummy, &dummy);
489         if (do_nonshared)
490                 dcss_command = DCSS_LOADNSR;
491         else
492         dcss_command = DCSS_LOADNOLY;
493         diag_cc = dcss_diag(dcss_command, seg->dcss_name,
494                         &seg->start_addr, &seg->end);
495         if (diag_cc > 1) {
496                 PRINT_WARN ("segment_modify_shared: could not reload segment %s"
497                                 " - diag returned error (%ld)\n",name,seg->end);
498                 rc = dcss_diag_translate_rc (seg->end);
499                 goto out_del;
500         }
501         seg->do_nonshared = do_nonshared;
502         rc = 0;
503         goto out_unlock;
504  out_del:
505         list_del(&seg->list);
506         dcss_diag(DCSS_PURGESEG, seg->dcss_name,
507                   &dummy, &dummy);
508         kfree (seg);
509  out_unlock:
510         spin_unlock(&dcss_lock);
511         return rc;
512 }
513
514 /*
515  * Decrease the use count of a DCSS segment and remove
516  * it from the address space if nobody is using it
517  * any longer.
518  */
519 void
520 segment_unload(char *name)
521 {
522         unsigned long dummy;
523         struct dcss_segment *seg;
524
525         if (!MACHINE_IS_VM)
526                 return;
527
528         spin_lock(&dcss_lock);
529         seg = segment_by_name (name);
530         if (seg == NULL) {
531                 PRINT_ERR ("could not find segment %s in segment_unload, "
532                                 "please report to linux390@de.ibm.com\n",name);
533                 goto out_unlock;
534         }
535         if (atomic_dec_return(&seg->ref_count) == 0) {
536                 list_del(&seg->list);
537                 dcss_diag(DCSS_PURGESEG, seg->dcss_name,
538                           &dummy, &dummy);
539                 kfree(seg);
540         }
541 out_unlock:
542         spin_unlock(&dcss_lock);
543 }
544
545 /*
546  * save segment content permanently
547  */
548 void
549 segment_save(char *name)
550 {
551         struct dcss_segment *seg;
552         int startpfn = 0;
553         int endpfn = 0;
554         char cmd1[160];
555         char cmd2[80];
556         int i;
557
558         if (!MACHINE_IS_VM)
559                 return;
560
561         spin_lock(&dcss_lock);
562         seg = segment_by_name (name);
563
564         if (seg == NULL) {
565                 PRINT_ERR ("could not find segment %s in segment_save, please report to linux390@de.ibm.com\n",name);
566                 return;
567         }
568
569         startpfn = seg->start_addr >> PAGE_SHIFT;
570         endpfn = (seg->end) >> PAGE_SHIFT;
571         sprintf(cmd1, "DEFSEG %s", name);
572         for (i=0; i<seg->segcnt; i++) {
573                 sprintf(cmd1+strlen(cmd1), " %X-%X %s",
574                         seg->range[i].start >> PAGE_SHIFT,
575                         seg->range[i].end >> PAGE_SHIFT,
576                         segtype_string[seg->range[i].start & 0xff]);
577         }
578         sprintf(cmd2, "SAVESEG %s", name);
579         cpcmd(cmd1, NULL, 0);
580         cpcmd(cmd2, NULL, 0);
581         spin_unlock(&dcss_lock);
582 }
583
584 EXPORT_SYMBOL(segment_load);
585 EXPORT_SYMBOL(segment_unload);
586 EXPORT_SYMBOL(segment_save);
587 EXPORT_SYMBOL(segment_type);
588 EXPORT_SYMBOL(segment_modify_shared);