1 // SPDX-License-Identifier: GPL-2.0
2 /*
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 * Copyright IBM Corp. 2002, 2004
8 */
9
10 #define KMSG_COMPONENT "extmem"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12
13 #include <linux/kernel.h>
14 #include <linux/string.h>
15 #include <linux/spinlock.h>
16 #include <linux/list.h>
17 #include <linux/slab.h>
18 #include <linux/export.h>
19 #include <linux/memblock.h>
20 #include <linux/ctype.h>
21 #include <linux/ioport.h>
22 #include <linux/refcount.h>
23 #include <linux/pgtable.h>
24 #include <asm/diag.h>
25 #include <asm/page.h>
26 #include <asm/ebcdic.h>
27 #include <asm/errno.h>
28 #include <asm/extmem.h>
29 #include <asm/cpcmd.h>
30 #include <asm/setup.h>
31
32 #define DCSS_PURGESEG 0x08
33 #define DCSS_LOADSHRX 0x20
34 #define DCSS_LOADNSRX 0x24
35 #define DCSS_FINDSEGX 0x2c
36 #define DCSS_SEGEXTX 0x38
37 #define DCSS_FINDSEGA 0x0c
38
39 struct qrange {
40 unsigned long start; /* last byte type */
41 unsigned long end; /* last byte reserved */
42 };
43
44 struct qout64 {
45 unsigned long segstart;
46 unsigned long segend;
47 int segcnt;
48 int segrcnt;
49 struct qrange range[6];
50 };
51
52 struct qin64 {
53 char qopcode;
54 char rsrv1[3];
55 char qrcode;
56 char rsrv2[3];
57 char qname[8];
58 unsigned int qoutptr;
59 short int qoutlen;
60 };
61
62 struct dcss_segment {
63 struct list_head list;
64 char dcss_name[8];
65 char res_name[16];
66 unsigned long start_addr;
67 unsigned long end;
68 refcount_t ref_count;
69 int do_nonshared;
70 unsigned int vm_segtype;
71 struct qrange range[6];
72 int segcnt;
73 struct resource *res;
74 };
75
76 static DEFINE_MUTEX(dcss_lock);
77 static LIST_HEAD(dcss_list);
78 static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
79 "EW/EN-MIXED" };
80 static int loadshr_scode = DCSS_LOADSHRX;
81 static int loadnsr_scode = DCSS_LOADNSRX;
82 static int purgeseg_scode = DCSS_PURGESEG;
83 static int segext_scode = DCSS_SEGEXTX;
84
85 /*
86 * Create the 8 bytes, ebcdic VM segment name from
87 * an ascii name.
88 */
89 static void
dcss_mkname(char * name,char * dcss_name)90 dcss_mkname(char *name, char *dcss_name)
91 {
92 int i;
93
94 for (i = 0; i < 8; i++) {
95 if (name[i] == '\0')
96 break;
97 dcss_name[i] = toupper(name[i]);
98 }
99 for (; i < 8; i++)
100 dcss_name[i] = ' ';
101 ASCEBC(dcss_name, 8);
102 }
103
104
105 /*
106 * search all segments in dcss_list, and return the one
107 * namend *name. If not found, return NULL.
108 */
109 static struct dcss_segment *
segment_by_name(char * name)110 segment_by_name (char *name)
111 {
112 char dcss_name[9];
113 struct list_head *l;
114 struct dcss_segment *tmp, *retval = NULL;
115
116 BUG_ON(!mutex_is_locked(&dcss_lock));
117 dcss_mkname (name, dcss_name);
118 list_for_each (l, &dcss_list) {
119 tmp = list_entry (l, struct dcss_segment, list);
120 if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
121 retval = tmp;
122 break;
123 }
124 }
125 return retval;
126 }
127
128
129 /*
130 * Perform a function on a dcss segment.
131 */
132 static inline int
dcss_diag(int * func,void * parameter,unsigned long * ret1,unsigned long * ret2)133 dcss_diag(int *func, void *parameter,
134 unsigned long *ret1, unsigned long *ret2)
135 {
136 unsigned long rx, ry;
137 int rc;
138
139 rx = (unsigned long) parameter;
140 ry = (unsigned long) *func;
141
142 diag_stat_inc(DIAG_STAT_X064);
143 asm volatile(
144 " diag %0,%1,0x64\n"
145 " ipm %2\n"
146 " srl %2,28\n"
147 : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
148 *ret1 = rx;
149 *ret2 = ry;
150 return rc;
151 }
152
153 static inline int
dcss_diag_translate_rc(int vm_rc)154 dcss_diag_translate_rc (int vm_rc) {
155 if (vm_rc == 44)
156 return -ENOENT;
157 return -EIO;
158 }
159
160
161 /* do a diag to get info about a segment.
162 * fills start_address, end and vm_segtype fields
163 */
164 static int
query_segment_type(struct dcss_segment * seg)165 query_segment_type (struct dcss_segment *seg)
166 {
167 unsigned long dummy, vmrc;
168 int diag_cc, rc, i;
169 struct qout64 *qout;
170 struct qin64 *qin;
171
172 qin = kmalloc(sizeof(*qin), GFP_KERNEL | GFP_DMA);
173 qout = kmalloc(sizeof(*qout), GFP_KERNEL | GFP_DMA);
174 if ((qin == NULL) || (qout == NULL)) {
175 rc = -ENOMEM;
176 goto out_free;
177 }
178
179 /* initialize diag input parameters */
180 qin->qopcode = DCSS_FINDSEGA;
181 qin->qoutptr = (unsigned long) qout;
182 qin->qoutlen = sizeof(struct qout64);
183 memcpy (qin->qname, seg->dcss_name, 8);
184
185 diag_cc = dcss_diag(&segext_scode, qin, &dummy, &vmrc);
186
187 if (diag_cc < 0) {
188 rc = diag_cc;
189 goto out_free;
190 }
191 if (diag_cc > 1) {
192 pr_warn("Querying a DCSS type failed with rc=%ld\n", vmrc);
193 rc = dcss_diag_translate_rc (vmrc);
194 goto out_free;
195 }
196
197 if (qout->segcnt > 6) {
198 rc = -EOPNOTSUPP;
199 goto out_free;
200 }
201
202 if (qout->segcnt == 1) {
203 seg->vm_segtype = qout->range[0].start & 0xff;
204 } else {
205 /* multi-part segment. only one type supported here:
206 - all parts are contiguous
207 - all parts are either EW or EN type
208 - maximum 6 parts allowed */
209 unsigned long start = qout->segstart >> PAGE_SHIFT;
210 for (i=0; i<qout->segcnt; i++) {
211 if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
212 ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
213 rc = -EOPNOTSUPP;
214 goto out_free;
215 }
216 if (start != qout->range[i].start >> PAGE_SHIFT) {
217 rc = -EOPNOTSUPP;
218 goto out_free;
219 }
220 start = (qout->range[i].end >> PAGE_SHIFT) + 1;
221 }
222 seg->vm_segtype = SEG_TYPE_EWEN;
223 }
224
225 /* analyze diag output and update seg */
226 seg->start_addr = qout->segstart;
227 seg->end = qout->segend;
228
229 memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
230 seg->segcnt = qout->segcnt;
231
232 rc = 0;
233
234 out_free:
235 kfree(qin);
236 kfree(qout);
237 return rc;
238 }
239
240 /*
241 * get info about a segment
242 * possible return values:
243 * -ENOSYS : we are not running on VM
244 * -EIO : could not perform query diagnose
245 * -ENOENT : no such segment
246 * -EOPNOTSUPP: multi-part segment cannot be used with linux
247 * -ENOMEM : out of memory
248 * 0 .. 6 : type of segment as defined in include/asm-s390/extmem.h
249 */
250 int
segment_type(char * name)251 segment_type (char* name)
252 {
253 int rc;
254 struct dcss_segment seg;
255
256 if (!MACHINE_IS_VM)
257 return -ENOSYS;
258
259 dcss_mkname(name, seg.dcss_name);
260 rc = query_segment_type (&seg);
261 if (rc < 0)
262 return rc;
263 return seg.vm_segtype;
264 }
265
266 /*
267 * check if segment collides with other segments that are currently loaded
268 * returns 1 if this is the case, 0 if no collision was found
269 */
270 static int
segment_overlaps_others(struct dcss_segment * seg)271 segment_overlaps_others (struct dcss_segment *seg)
272 {
273 struct list_head *l;
274 struct dcss_segment *tmp;
275
276 BUG_ON(!mutex_is_locked(&dcss_lock));
277 list_for_each(l, &dcss_list) {
278 tmp = list_entry(l, struct dcss_segment, list);
279 if ((tmp->start_addr >> 20) > (seg->end >> 20))
280 continue;
281 if ((tmp->end >> 20) < (seg->start_addr >> 20))
282 continue;
283 if (seg == tmp)
284 continue;
285 return 1;
286 }
287 return 0;
288 }
289
290 /*
291 * real segment loading function, called from segment_load
292 * Must return either an error code < 0, or the segment type code >= 0
293 */
294 static int
__segment_load(char * name,int do_nonshared,unsigned long * addr,unsigned long * end)295 __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
296 {
297 unsigned long start_addr, end_addr, dummy;
298 struct dcss_segment *seg;
299 int rc, diag_cc, segtype;
300
301 start_addr = end_addr = 0;
302 segtype = -1;
303 seg = kmalloc(sizeof(*seg), GFP_KERNEL | GFP_DMA);
304 if (seg == NULL) {
305 rc = -ENOMEM;
306 goto out;
307 }
308 dcss_mkname (name, seg->dcss_name);
309 rc = query_segment_type (seg);
310 if (rc < 0)
311 goto out_free;
312
313 if (segment_overlaps_others(seg)) {
314 rc = -EBUSY;
315 goto out_free;
316 }
317
318 seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
319 if (seg->res == NULL) {
320 rc = -ENOMEM;
321 goto out_free;
322 }
323 seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
324 seg->res->start = seg->start_addr;
325 seg->res->end = seg->end;
326 memcpy(&seg->res_name, seg->dcss_name, 8);
327 EBCASC(seg->res_name, 8);
328 seg->res_name[8] = '\0';
329 strlcat(seg->res_name, " (DCSS)", sizeof(seg->res_name));
330 seg->res->name = seg->res_name;
331 segtype = seg->vm_segtype;
332 if (segtype == SEG_TYPE_SC ||
333 ((segtype == SEG_TYPE_SR || segtype == SEG_TYPE_ER) && !do_nonshared))
334 seg->res->flags |= IORESOURCE_READONLY;
335
336 /* Check for overlapping resources before adding the mapping. */
337 if (request_resource(&iomem_resource, seg->res)) {
338 rc = -EBUSY;
339 goto out_free_resource;
340 }
341
342 rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
343 if (rc)
344 goto out_resource;
345
346 if (do_nonshared)
347 diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
348 &start_addr, &end_addr);
349 else
350 diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
351 &start_addr, &end_addr);
352 if (diag_cc < 0) {
353 dcss_diag(&purgeseg_scode, seg->dcss_name,
354 &dummy, &dummy);
355 rc = diag_cc;
356 goto out_mapping;
357 }
358 if (diag_cc > 1) {
359 pr_warn("Loading DCSS %s failed with rc=%ld\n", name, end_addr);
360 rc = dcss_diag_translate_rc(end_addr);
361 dcss_diag(&purgeseg_scode, seg->dcss_name,
362 &dummy, &dummy);
363 goto out_mapping;
364 }
365 seg->start_addr = start_addr;
366 seg->end = end_addr;
367 seg->do_nonshared = do_nonshared;
368 refcount_set(&seg->ref_count, 1);
369 list_add(&seg->list, &dcss_list);
370 *addr = seg->start_addr;
371 *end = seg->end;
372 if (do_nonshared)
373 pr_info("DCSS %s of range %px to %px and type %s loaded as "
374 "exclusive-writable\n", name, (void*) seg->start_addr,
375 (void*) seg->end, segtype_string[seg->vm_segtype]);
376 else {
377 pr_info("DCSS %s of range %px to %px and type %s loaded in "
378 "shared access mode\n", name, (void*) seg->start_addr,
379 (void*) seg->end, segtype_string[seg->vm_segtype]);
380 }
381 goto out;
382 out_mapping:
383 vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
384 out_resource:
385 release_resource(seg->res);
386 out_free_resource:
387 kfree(seg->res);
388 out_free:
389 kfree(seg);
390 out:
391 return rc < 0 ? rc : segtype;
392 }
393
394 /*
395 * this function loads a DCSS segment
396 * name : name of the DCSS
397 * do_nonshared : 0 indicates that the dcss should be shared with other linux images
398 * 1 indicates that the dcss should be exclusive for this linux image
399 * addr : will be filled with start address of the segment
400 * end : will be filled with end address of the segment
401 * return values:
402 * -ENOSYS : we are not running on VM
403 * -EIO : could not perform query or load diagnose
404 * -ENOENT : no such segment
405 * -EOPNOTSUPP: multi-part segment cannot be used with linux
406 * -EBUSY : segment cannot be used (overlaps with dcss or storage)
407 * -ERANGE : segment cannot be used (exceeds kernel mapping range)
408 * -EPERM : segment is currently loaded with incompatible permissions
409 * -ENOMEM : out of memory
410 * 0 .. 6 : type of segment as defined in include/asm-s390/extmem.h
411 */
412 int
segment_load(char * name,int do_nonshared,unsigned long * addr,unsigned long * end)413 segment_load (char *name, int do_nonshared, unsigned long *addr,
414 unsigned long *end)
415 {
416 struct dcss_segment *seg;
417 int rc;
418
419 if (!MACHINE_IS_VM)
420 return -ENOSYS;
421
422 mutex_lock(&dcss_lock);
423 seg = segment_by_name (name);
424 if (seg == NULL)
425 rc = __segment_load (name, do_nonshared, addr, end);
426 else {
427 if (do_nonshared == seg->do_nonshared) {
428 refcount_inc(&seg->ref_count);
429 *addr = seg->start_addr;
430 *end = seg->end;
431 rc = seg->vm_segtype;
432 } else {
433 *addr = *end = 0;
434 rc = -EPERM;
435 }
436 }
437 mutex_unlock(&dcss_lock);
438 return rc;
439 }
440
441 /*
442 * this function modifies the shared state of a DCSS segment. note that
443 * name : name of the DCSS
444 * do_nonshared : 0 indicates that the dcss should be shared with other linux images
445 * 1 indicates that the dcss should be exclusive for this linux image
446 * return values:
447 * -EIO : could not perform load diagnose (segment gone!)
448 * -ENOENT : no such segment (segment gone!)
449 * -EAGAIN : segment is in use by other exploiters, try later
450 * -EINVAL : no segment with the given name is currently loaded - name invalid
451 * -EBUSY : segment can temporarily not be used (overlaps with dcss)
452 * 0 : operation succeeded
453 */
454 int
segment_modify_shared(char * name,int do_nonshared)455 segment_modify_shared (char *name, int do_nonshared)
456 {
457 struct dcss_segment *seg;
458 unsigned long start_addr, end_addr, dummy;
459 int rc, diag_cc;
460
461 start_addr = end_addr = 0;
462 mutex_lock(&dcss_lock);
463 seg = segment_by_name (name);
464 if (seg == NULL) {
465 rc = -EINVAL;
466 goto out_unlock;
467 }
468 if (do_nonshared == seg->do_nonshared) {
469 pr_info("DCSS %s is already in the requested access "
470 "mode\n", name);
471 rc = 0;
472 goto out_unlock;
473 }
474 if (refcount_read(&seg->ref_count) != 1) {
475 pr_warn("DCSS %s is in use and cannot be reloaded\n", name);
476 rc = -EAGAIN;
477 goto out_unlock;
478 }
479 release_resource(seg->res);
480 if (do_nonshared)
481 seg->res->flags &= ~IORESOURCE_READONLY;
482 else
483 if (seg->vm_segtype == SEG_TYPE_SR ||
484 seg->vm_segtype == SEG_TYPE_ER)
485 seg->res->flags |= IORESOURCE_READONLY;
486
487 if (request_resource(&iomem_resource, seg->res)) {
488 pr_warn("DCSS %s overlaps with used memory resources and cannot be reloaded\n",
489 name);
490 rc = -EBUSY;
491 kfree(seg->res);
492 goto out_del_mem;
493 }
494
495 dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
496 if (do_nonshared)
497 diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
498 &start_addr, &end_addr);
499 else
500 diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
501 &start_addr, &end_addr);
502 if (diag_cc < 0) {
503 rc = diag_cc;
504 goto out_del_res;
505 }
506 if (diag_cc > 1) {
507 pr_warn("Reloading DCSS %s failed with rc=%ld\n",
508 name, end_addr);
509 rc = dcss_diag_translate_rc(end_addr);
510 goto out_del_res;
511 }
512 seg->start_addr = start_addr;
513 seg->end = end_addr;
514 seg->do_nonshared = do_nonshared;
515 rc = 0;
516 goto out_unlock;
517 out_del_res:
518 release_resource(seg->res);
519 kfree(seg->res);
520 out_del_mem:
521 vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
522 list_del(&seg->list);
523 dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
524 kfree(seg);
525 out_unlock:
526 mutex_unlock(&dcss_lock);
527 return rc;
528 }
529
530 /*
531 * Decrease the use count of a DCSS segment and remove
532 * it from the address space if nobody is using it
533 * any longer.
534 */
535 void
segment_unload(char * name)536 segment_unload(char *name)
537 {
538 unsigned long dummy;
539 struct dcss_segment *seg;
540
541 if (!MACHINE_IS_VM)
542 return;
543
544 mutex_lock(&dcss_lock);
545 seg = segment_by_name (name);
546 if (seg == NULL) {
547 pr_err("Unloading unknown DCSS %s failed\n", name);
548 goto out_unlock;
549 }
550 if (!refcount_dec_and_test(&seg->ref_count))
551 goto out_unlock;
552 release_resource(seg->res);
553 kfree(seg->res);
554 vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
555 list_del(&seg->list);
556 dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
557 kfree(seg);
558 out_unlock:
559 mutex_unlock(&dcss_lock);
560 }
561
562 /*
563 * save segment content permanently
564 */
565 void
segment_save(char * name)566 segment_save(char *name)
567 {
568 struct dcss_segment *seg;
569 char cmd1[160];
570 char cmd2[80];
571 int i, response;
572
573 if (!MACHINE_IS_VM)
574 return;
575
576 mutex_lock(&dcss_lock);
577 seg = segment_by_name (name);
578
579 if (seg == NULL) {
580 pr_err("Saving unknown DCSS %s failed\n", name);
581 goto out;
582 }
583
584 sprintf(cmd1, "DEFSEG %s", name);
585 for (i=0; i<seg->segcnt; i++) {
586 sprintf(cmd1+strlen(cmd1), " %lX-%lX %s",
587 seg->range[i].start >> PAGE_SHIFT,
588 seg->range[i].end >> PAGE_SHIFT,
589 segtype_string[seg->range[i].start & 0xff]);
590 }
591 sprintf(cmd2, "SAVESEG %s", name);
592 response = 0;
593 cpcmd(cmd1, NULL, 0, &response);
594 if (response) {
595 pr_err("Saving a DCSS failed with DEFSEG response code "
596 "%i\n", response);
597 goto out;
598 }
599 cpcmd(cmd2, NULL, 0, &response);
600 if (response) {
601 pr_err("Saving a DCSS failed with SAVESEG response code "
602 "%i\n", response);
603 goto out;
604 }
605 out:
606 mutex_unlock(&dcss_lock);
607 }
608
609 /*
610 * print appropriate error message for segment_load()/segment_type()
611 * return code
612 */
segment_warning(int rc,char * seg_name)613 void segment_warning(int rc, char *seg_name)
614 {
615 switch (rc) {
616 case -ENOENT:
617 pr_err("DCSS %s cannot be loaded or queried\n", seg_name);
618 break;
619 case -ENOSYS:
620 pr_err("DCSS %s cannot be loaded or queried without "
621 "z/VM\n", seg_name);
622 break;
623 case -EIO:
624 pr_err("Loading or querying DCSS %s resulted in a "
625 "hardware error\n", seg_name);
626 break;
627 case -EOPNOTSUPP:
628 pr_err("DCSS %s has multiple page ranges and cannot be "
629 "loaded or queried\n", seg_name);
630 break;
631 case -EBUSY:
632 pr_err("%s needs used memory resources and cannot be "
633 "loaded or queried\n", seg_name);
634 break;
635 case -EPERM:
636 pr_err("DCSS %s is already loaded in a different access "
637 "mode\n", seg_name);
638 break;
639 case -ENOMEM:
640 pr_err("There is not enough memory to load or query "
641 "DCSS %s\n", seg_name);
642 break;
643 case -ERANGE: {
644 struct range mhp_range = arch_get_mappable_range();
645
646 pr_err("DCSS %s exceeds the kernel mapping range (%llu) "
647 "and cannot be loaded\n", seg_name, mhp_range.end + 1);
648 break;
649 }
650 default:
651 break;
652 }
653 }
654
655 EXPORT_SYMBOL(segment_load);
656 EXPORT_SYMBOL(segment_unload);
657 EXPORT_SYMBOL(segment_save);
658 EXPORT_SYMBOL(segment_type);
659 EXPORT_SYMBOL(segment_modify_shared);
660 EXPORT_SYMBOL(segment_warning);
661
