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 pr_fmt(fmt) "extmem: " fmt
11
12#include <linux/kernel.h>
13#include <linux/string.h>
14#include <linux/spinlock.h>
15#include <linux/list.h>
16#include <linux/slab.h>
17#include <linux/export.h>
18#include <linux/memblock.h>
19#include <linux/ctype.h>
20#include <linux/ioport.h>
21#include <linux/refcount.h>
22#include <linux/pgtable.h>
23#include <asm/machine.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#include <asm/asm.h>
32
33#define DCSS_PURGESEG 0x08
34#define DCSS_LOADSHRX 0x20
35#define DCSS_LOADNSRX 0x24
36#define DCSS_FINDSEGX 0x2c
37#define DCSS_SEGEXTX 0x38
38#define DCSS_FINDSEGA 0x0c
39
40struct qrange {
41 unsigned long start; /* last byte type */
42 unsigned long end; /* last byte reserved */
43};
44
45struct qout64 {
46 unsigned long segstart;
47 unsigned long segend;
48 int segcnt;
49 int segrcnt;
50 struct qrange range[6];
51};
52
53struct qin64 {
54 char qopcode;
55 char rsrv1[3];
56 char qrcode;
57 char rsrv2[3];
58 char qname[8];
59 unsigned int qoutptr;
60 short int qoutlen;
61};
62
63struct dcss_segment {
64 struct list_head list;
65 char dcss_name[8];
66 char res_name[16];
67 unsigned long start_addr;
68 unsigned long end;
69 refcount_t ref_count;
70 int do_nonshared;
71 unsigned int vm_segtype;
72 struct qrange range[6];
73 int segcnt;
74 struct resource *res;
75};
76
77static DEFINE_MUTEX(dcss_lock);
78static LIST_HEAD(dcss_list);
79static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
80 "EW/EN-MIXED" };
81static int loadshr_scode = DCSS_LOADSHRX;
82static int loadnsr_scode = DCSS_LOADNSRX;
83static int purgeseg_scode = DCSS_PURGESEG;
84static int segext_scode = DCSS_SEGEXTX;
85
86/*
87 * Create the 8 bytes, ebcdic VM segment name from
88 * an ascii name.
89 */
90static void
91dcss_mkname(char *name, char *dcss_name)
92{
93 int i;
94
95 for (i = 0; i < 8; i++) {
96 if (name[i] == '\0')
97 break;
98 dcss_name[i] = toupper(name[i]);
99 }
100 for (; i < 8; i++)
101 dcss_name[i] = ' ';
102 ASCEBC(dcss_name, 8);
103}
104
105
106/*
107 * search all segments in dcss_list, and return the one
108 * namend *name. If not found, return NULL.
109 */
110static struct dcss_segment *
111segment_by_name (char *name)
112{
113 char dcss_name[9];
114 struct list_head *l;
115 struct dcss_segment *tmp, *retval = NULL;
116
117 BUG_ON(!mutex_is_locked(&dcss_lock));
118 dcss_mkname (name, dcss_name);
119 list_for_each (l, &dcss_list) {
120 tmp = list_entry (l, struct dcss_segment, list);
121 if (memcmp(p: tmp->dcss_name, q: dcss_name, size: 8) == 0) {
122 retval = tmp;
123 break;
124 }
125 }
126 return retval;
127}
128
129
130/*
131 * Perform a function on a dcss segment.
132 */
133static inline int
134dcss_diag(int *func, void *parameter,
135 unsigned long *ret1, unsigned long *ret2)
136{
137 unsigned long rx, ry;
138 int cc;
139
140 rx = virt_to_phys(address: parameter);
141 ry = (unsigned long) *func;
142
143 diag_stat_inc(DIAG_STAT_X064);
144 asm volatile(
145 " diag %[rx],%[ry],0x64\n"
146 CC_IPM(cc)
147 : CC_OUT(cc, cc), [rx] "+d" (rx), [ry] "+d" (ry)
148 :
149 : CC_CLOBBER);
150 *ret1 = rx;
151 *ret2 = ry;
152 return CC_TRANSFORM(cc);
153}
154
155static inline int
156dcss_diag_translate_rc (int vm_rc) {
157 if (vm_rc == 44)
158 return -ENOENT;
159 return -EIO;
160}
161
162
163/* do a diag to get info about a segment.
164 * fills start_address, end and vm_segtype fields
165 */
166static int
167query_segment_type (struct dcss_segment *seg)
168{
169 unsigned long dummy, vmrc;
170 int diag_cc, rc, i;
171 struct qout64 *qout;
172 struct qin64 *qin;
173
174 qin = kmalloc(sizeof(*qin), GFP_KERNEL | GFP_DMA);
175 qout = kmalloc(sizeof(*qout), GFP_KERNEL | GFP_DMA);
176 if ((qin == NULL) || (qout == NULL)) {
177 rc = -ENOMEM;
178 goto out_free;
179 }
180
181 /* initialize diag input parameters */
182 qin->qopcode = DCSS_FINDSEGA;
183 qin->qoutptr = virt_to_phys(address: qout);
184 qin->qoutlen = sizeof(struct qout64);
185 memcpy (qin->qname, seg->dcss_name, 8);
186
187 diag_cc = dcss_diag(func: &segext_scode, parameter: qin, ret1: &dummy, ret2: &vmrc);
188
189 if (diag_cc < 0) {
190 rc = diag_cc;
191 goto out_free;
192 }
193 if (diag_cc > 1) {
194 pr_warn("Querying a DCSS type failed with rc=%ld\n", vmrc);
195 rc = dcss_diag_translate_rc (vm_rc: vmrc);
196 goto out_free;
197 }
198
199 if (qout->segcnt > 6) {
200 rc = -EOPNOTSUPP;
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 = -EOPNOTSUPP;
216 goto out_free;
217 }
218 if (start != qout->range[i].start >> PAGE_SHIFT) {
219 rc = -EOPNOTSUPP;
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 kfree(objp: qin);
238 kfree(objp: qout);
239 return rc;
240}
241
242/*
243 * get info about a segment
244 * possible return values:
245 * -ENOSYS : we are not running on VM
246 * -EIO : could not perform query diagnose
247 * -ENOENT : no such segment
248 * -EOPNOTSUPP: multi-part segment cannot be used with linux
249 * -ENOMEM : out of memory
250 * 0 .. 6 : type of segment as defined in include/asm-s390/extmem.h
251 */
252int
253segment_type (char* name)
254{
255 int rc;
256 struct dcss_segment seg;
257
258 if (!machine_is_vm())
259 return -ENOSYS;
260
261 dcss_mkname(name, dcss_name: seg.dcss_name);
262 rc = query_segment_type (seg: &seg);
263 if (rc < 0)
264 return rc;
265 return seg.vm_segtype;
266}
267
268/*
269 * check if segment collides with other segments that are currently loaded
270 * returns 1 if this is the case, 0 if no collision was found
271 */
272static int
273segment_overlaps_others (struct dcss_segment *seg)
274{
275 struct list_head *l;
276 struct dcss_segment *tmp;
277
278 BUG_ON(!mutex_is_locked(&dcss_lock));
279 list_for_each(l, &dcss_list) {
280 tmp = list_entry(l, struct dcss_segment, list);
281 if ((tmp->start_addr >> 20) > (seg->end >> 20))
282 continue;
283 if ((tmp->end >> 20) < (seg->start_addr >> 20))
284 continue;
285 if (seg == tmp)
286 continue;
287 return 1;
288 }
289 return 0;
290}
291
292/*
293 * real segment loading function, called from segment_load
294 * Must return either an error code < 0, or the segment type code >= 0
295 */
296static int
297__segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
298{
299 unsigned long start_addr, end_addr, dummy;
300 struct dcss_segment *seg;
301 int rc, diag_cc, segtype;
302
303 start_addr = end_addr = 0;
304 segtype = -1;
305 seg = kmalloc(sizeof(*seg), GFP_KERNEL | GFP_DMA);
306 if (seg == NULL) {
307 rc = -ENOMEM;
308 goto out;
309 }
310 dcss_mkname (name, dcss_name: seg->dcss_name);
311 rc = query_segment_type (seg);
312 if (rc < 0)
313 goto out_free;
314
315 if (segment_overlaps_others(seg)) {
316 rc = -EBUSY;
317 goto out_free;
318 }
319
320 seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
321 if (seg->res == NULL) {
322 rc = -ENOMEM;
323 goto out_free;
324 }
325 seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
326 seg->res->start = seg->start_addr;
327 seg->res->end = seg->end;
328 memcpy(&seg->res_name, seg->dcss_name, 8);
329 EBCASC(seg->res_name, 8);
330 seg->res_name[8] = '\0';
331 strlcat(p: seg->res_name, q: " (DCSS)", avail: sizeof(seg->res_name));
332 seg->res->name = seg->res_name;
333 segtype = seg->vm_segtype;
334 if (segtype == SEG_TYPE_SC ||
335 ((segtype == SEG_TYPE_SR || segtype == SEG_TYPE_ER) && !do_nonshared))
336 seg->res->flags |= IORESOURCE_READONLY;
337
338 /* Check for overlapping resources before adding the mapping. */
339 if (request_resource(root: &iomem_resource, new: seg->res)) {
340 rc = -EBUSY;
341 goto out_free_resource;
342 }
343
344 rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
345 if (rc)
346 goto out_resource;
347
348 if (do_nonshared)
349 diag_cc = dcss_diag(func: &loadnsr_scode, parameter: seg->dcss_name,
350 ret1: &start_addr, ret2: &end_addr);
351 else
352 diag_cc = dcss_diag(func: &loadshr_scode, parameter: seg->dcss_name,
353 ret1: &start_addr, ret2: &end_addr);
354 if (diag_cc < 0) {
355 dcss_diag(func: &purgeseg_scode, parameter: seg->dcss_name,
356 ret1: &dummy, ret2: &dummy);
357 rc = diag_cc;
358 goto out_mapping;
359 }
360 if (diag_cc > 1) {
361 pr_warn("Loading DCSS %s failed with rc=%ld\n", name, end_addr);
362 rc = dcss_diag_translate_rc(vm_rc: end_addr);
363 dcss_diag(func: &purgeseg_scode, parameter: seg->dcss_name,
364 ret1: &dummy, ret2: &dummy);
365 goto out_mapping;
366 }
367 seg->start_addr = start_addr;
368 seg->end = end_addr;
369 seg->do_nonshared = do_nonshared;
370 refcount_set(r: &seg->ref_count, n: 1);
371 list_add(new: &seg->list, head: &dcss_list);
372 *addr = seg->start_addr;
373 *end = seg->end;
374 if (do_nonshared)
375 pr_info("DCSS %s of range %px to %px and type %s loaded as "
376 "exclusive-writable\n", name, (void*) seg->start_addr,
377 (void*) seg->end, segtype_string[seg->vm_segtype]);
378 else {
379 pr_info("DCSS %s of range %px to %px and type %s loaded in "
380 "shared access mode\n", name, (void*) seg->start_addr,
381 (void*) seg->end, segtype_string[seg->vm_segtype]);
382 }
383 goto out;
384 out_mapping:
385 vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
386 out_resource:
387 release_resource(new: seg->res);
388 out_free_resource:
389 kfree(objp: seg->res);
390 out_free:
391 kfree(objp: seg);
392 out:
393 return rc < 0 ? rc : segtype;
394}
395
396/*
397 * this function loads a DCSS segment
398 * name : name of the DCSS
399 * do_nonshared : 0 indicates that the dcss should be shared with other linux images
400 * 1 indicates that the dcss should be exclusive for this linux image
401 * addr : will be filled with start address of the segment
402 * end : will be filled with end address of the segment
403 * return values:
404 * -ENOSYS : we are not running on VM
405 * -EIO : could not perform query or load diagnose
406 * -ENOENT : no such segment
407 * -EOPNOTSUPP: multi-part segment cannot be used with linux
408 * -EBUSY : segment cannot be used (overlaps with dcss or storage)
409 * -ERANGE : segment cannot be used (exceeds kernel mapping range)
410 * -EPERM : segment is currently loaded with incompatible permissions
411 * -ENOMEM : out of memory
412 * 0 .. 6 : type of segment as defined in include/asm-s390/extmem.h
413 */
414int
415segment_load (char *name, int do_nonshared, unsigned long *addr,
416 unsigned long *end)
417{
418 struct dcss_segment *seg;
419 int rc;
420
421 if (!machine_is_vm())
422 return -ENOSYS;
423
424 mutex_lock(&dcss_lock);
425 seg = segment_by_name (name);
426 if (seg == NULL)
427 rc = __segment_load (name, do_nonshared, addr, end);
428 else {
429 if (do_nonshared == seg->do_nonshared) {
430 refcount_inc(r: &seg->ref_count);
431 *addr = seg->start_addr;
432 *end = seg->end;
433 rc = seg->vm_segtype;
434 } else {
435 *addr = *end = 0;
436 rc = -EPERM;
437 }
438 }
439 mutex_unlock(lock: &dcss_lock);
440 return rc;
441}
442
443/*
444 * this function modifies the shared state of a DCSS segment. note that
445 * name : name of the DCSS
446 * do_nonshared : 0 indicates that the dcss should be shared with other linux images
447 * 1 indicates that the dcss should be exclusive for this linux image
448 * return values:
449 * -EIO : could not perform load diagnose (segment gone!)
450 * -ENOENT : no such segment (segment gone!)
451 * -EAGAIN : segment is in use by other exploiters, try later
452 * -EINVAL : no segment with the given name is currently loaded - name invalid
453 * -EBUSY : segment can temporarily not be used (overlaps with dcss)
454 * 0 : operation succeeded
455 */
456int
457segment_modify_shared (char *name, int do_nonshared)
458{
459 struct dcss_segment *seg;
460 unsigned long start_addr, end_addr, dummy;
461 int rc, diag_cc;
462
463 start_addr = end_addr = 0;
464 mutex_lock(&dcss_lock);
465 seg = segment_by_name (name);
466 if (seg == NULL) {
467 rc = -EINVAL;
468 goto out_unlock;
469 }
470 if (do_nonshared == seg->do_nonshared) {
471 pr_info("DCSS %s is already in the requested access "
472 "mode\n", name);
473 rc = 0;
474 goto out_unlock;
475 }
476 if (refcount_read(r: &seg->ref_count) != 1) {
477 pr_warn("DCSS %s is in use and cannot be reloaded\n", name);
478 rc = -EAGAIN;
479 goto out_unlock;
480 }
481 release_resource(new: seg->res);
482 if (do_nonshared)
483 seg->res->flags &= ~IORESOURCE_READONLY;
484 else
485 if (seg->vm_segtype == SEG_TYPE_SR ||
486 seg->vm_segtype == SEG_TYPE_ER)
487 seg->res->flags |= IORESOURCE_READONLY;
488
489 if (request_resource(root: &iomem_resource, new: seg->res)) {
490 pr_warn("DCSS %s overlaps with used memory resources and cannot be reloaded\n",
491 name);
492 rc = -EBUSY;
493 kfree(objp: seg->res);
494 goto out_del_mem;
495 }
496
497 dcss_diag(func: &purgeseg_scode, parameter: seg->dcss_name, ret1: &dummy, ret2: &dummy);
498 if (do_nonshared)
499 diag_cc = dcss_diag(func: &loadnsr_scode, parameter: seg->dcss_name,
500 ret1: &start_addr, ret2: &end_addr);
501 else
502 diag_cc = dcss_diag(func: &loadshr_scode, parameter: seg->dcss_name,
503 ret1: &start_addr, ret2: &end_addr);
504 if (diag_cc < 0) {
505 rc = diag_cc;
506 goto out_del_res;
507 }
508 if (diag_cc > 1) {
509 pr_warn("Reloading DCSS %s failed with rc=%ld\n",
510 name, end_addr);
511 rc = dcss_diag_translate_rc(vm_rc: end_addr);
512 goto out_del_res;
513 }
514 seg->start_addr = start_addr;
515 seg->end = end_addr;
516 seg->do_nonshared = do_nonshared;
517 rc = 0;
518 goto out_unlock;
519 out_del_res:
520 release_resource(new: seg->res);
521 kfree(objp: seg->res);
522 out_del_mem:
523 vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
524 list_del(entry: &seg->list);
525 dcss_diag(func: &purgeseg_scode, parameter: seg->dcss_name, ret1: &dummy, ret2: &dummy);
526 kfree(objp: seg);
527 out_unlock:
528 mutex_unlock(lock: &dcss_lock);
529 return rc;
530}
531
532static void __dcss_diag_purge_on_cpu_0(void *data)
533{
534 struct dcss_segment *seg = (struct dcss_segment *)data;
535 unsigned long dummy;
536
537 dcss_diag(func: &purgeseg_scode, parameter: seg->dcss_name, ret1: &dummy, ret2: &dummy);
538}
539
540/*
541 * Decrease the use count of a DCSS segment and remove
542 * it from the address space if nobody is using it
543 * any longer.
544 */
545void
546segment_unload(char *name)
547{
548 struct dcss_segment *seg;
549
550 if (!machine_is_vm())
551 return;
552
553 mutex_lock(&dcss_lock);
554 seg = segment_by_name (name);
555 if (seg == NULL) {
556 pr_err("Unloading unknown DCSS %s failed\n", name);
557 goto out_unlock;
558 }
559 if (!refcount_dec_and_test(r: &seg->ref_count))
560 goto out_unlock;
561 release_resource(new: seg->res);
562 kfree(objp: seg->res);
563 vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
564 list_del(entry: &seg->list);
565 /*
566 * Workaround for z/VM issue, where calling the DCSS unload diag on
567 * a non-IPL CPU would cause bogus sclp maximum memory detection on
568 * next IPL.
569 * IPL CPU 0 cannot be set offline, so the dcss_diag() call can
570 * directly be scheduled to that CPU.
571 */
572 smp_call_function_single(cpuid: 0, func: __dcss_diag_purge_on_cpu_0, info: seg, wait: 1);
573 kfree(objp: seg);
574out_unlock:
575 mutex_unlock(lock: &dcss_lock);
576}
577
578/*
579 * save segment content permanently
580 */
581void
582segment_save(char *name)
583{
584 struct dcss_segment *seg;
585 char cmd1[160];
586 char cmd2[80];
587 int i, response;
588
589 if (!machine_is_vm())
590 return;
591
592 mutex_lock(&dcss_lock);
593 seg = segment_by_name (name);
594
595 if (seg == NULL) {
596 pr_err("Saving unknown DCSS %s failed\n", name);
597 goto out;
598 }
599
600 snprintf(buf: cmd1, size: sizeof(cmd1), fmt: "DEFSEG %s", name);
601 for (i=0; i<seg->segcnt; i++) {
602 size_t len = strlen(cmd1);
603
604 snprintf(buf: cmd1 + len, size: sizeof(cmd1) - len, fmt: " %lX-%lX %s",
605 seg->range[i].start >> PAGE_SHIFT,
606 seg->range[i].end >> PAGE_SHIFT,
607 segtype_string[seg->range[i].start & 0xff]);
608 }
609 snprintf(buf: cmd2, size: sizeof(cmd2), fmt: "SAVESEG %s", name);
610 response = 0;
611 cpcmd(cmd1, NULL, 0, &response);
612 if (response) {
613 pr_err("Saving a DCSS failed with DEFSEG response code "
614 "%i\n", response);
615 goto out;
616 }
617 cpcmd(cmd2, NULL, 0, &response);
618 if (response) {
619 pr_err("Saving a DCSS failed with SAVESEG response code "
620 "%i\n", response);
621 goto out;
622 }
623out:
624 mutex_unlock(lock: &dcss_lock);
625}
626
627/*
628 * print appropriate error message for segment_load()/segment_type()
629 * return code
630 */
631void segment_warning(int rc, char *seg_name)
632{
633 switch (rc) {
634 case -ENOENT:
635 pr_err("DCSS %s cannot be loaded or queried\n", seg_name);
636 break;
637 case -ENOSYS:
638 pr_err("DCSS %s cannot be loaded or queried without "
639 "z/VM\n", seg_name);
640 break;
641 case -EIO:
642 pr_err("Loading or querying DCSS %s resulted in a "
643 "hardware error\n", seg_name);
644 break;
645 case -EOPNOTSUPP:
646 pr_err("DCSS %s has multiple page ranges and cannot be "
647 "loaded or queried\n", seg_name);
648 break;
649 case -EBUSY:
650 pr_err("%s needs used memory resources and cannot be "
651 "loaded or queried\n", seg_name);
652 break;
653 case -EPERM:
654 pr_err("DCSS %s is already loaded in a different access "
655 "mode\n", seg_name);
656 break;
657 case -ENOMEM:
658 pr_err("There is not enough memory to load or query "
659 "DCSS %s\n", seg_name);
660 break;
661 case -ERANGE: {
662 struct range mhp_range = arch_get_mappable_range();
663
664 pr_err("DCSS %s exceeds the kernel mapping range (%llu) "
665 "and cannot be loaded\n", seg_name, mhp_range.end + 1);
666 break;
667 }
668 default:
669 break;
670 }
671}
672
673EXPORT_SYMBOL(segment_load);
674EXPORT_SYMBOL(segment_unload);
675EXPORT_SYMBOL(segment_save);
676EXPORT_SYMBOL(segment_type);
677EXPORT_SYMBOL(segment_modify_shared);
678EXPORT_SYMBOL(segment_warning);
679

source code of linux/arch/s390/mm/extmem.c