Linux 4.13.16
[linux/fpc-iii.git] / arch / s390 / mm / extmem.c
blob9f118629b55fb64069fc90c6b1e816aa19d25e62
1 /*
2 * Author(s)......: Carsten Otte <cotte@de.ibm.com>
3 * Rob M van der Heij <rvdheij@nl.ibm.com>
4 * Steven Shultz <shultzss@us.ibm.com>
5 * Bugreports.to..: <Linux390@de.ibm.com>
6 * Copyright IBM Corp. 2002, 2004
7 */
9 #define KMSG_COMPONENT "extmem"
10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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/bootmem.h>
19 #include <linux/ctype.h>
20 #include <linux/ioport.h>
21 #include <asm/diag.h>
22 #include <asm/page.h>
23 #include <asm/pgtable.h>
24 #include <asm/ebcdic.h>
25 #include <asm/errno.h>
26 #include <asm/extmem.h>
27 #include <asm/cpcmd.h>
28 #include <asm/setup.h>
30 #define DCSS_LOADSHR 0x00
31 #define DCSS_LOADNSR 0x04
32 #define DCSS_PURGESEG 0x08
33 #define DCSS_FINDSEG 0x0c
34 #define DCSS_LOADNOLY 0x10
35 #define DCSS_SEGEXT 0x18
36 #define DCSS_LOADSHRX 0x20
37 #define DCSS_LOADNSRX 0x24
38 #define DCSS_FINDSEGX 0x2c
39 #define DCSS_SEGEXTX 0x38
40 #define DCSS_FINDSEGA 0x0c
42 struct qrange {
43 unsigned long start; /* last byte type */
44 unsigned long end; /* last byte reserved */
47 struct qout64 {
48 unsigned long segstart;
49 unsigned long segend;
50 int segcnt;
51 int segrcnt;
52 struct qrange range[6];
55 struct qrange_old {
56 unsigned int start; /* last byte type */
57 unsigned int end; /* last byte reserved */
60 /* output area format for the Diag x'64' old subcode x'18' */
61 struct qout64_old {
62 int segstart;
63 int segend;
64 int segcnt;
65 int segrcnt;
66 struct qrange_old range[6];
69 struct qin64 {
70 char qopcode;
71 char rsrv1[3];
72 char qrcode;
73 char rsrv2[3];
74 char qname[8];
75 unsigned int qoutptr;
76 short int qoutlen;
79 struct dcss_segment {
80 struct list_head list;
81 char dcss_name[8];
82 char res_name[15];
83 unsigned long start_addr;
84 unsigned long end;
85 atomic_t ref_count;
86 int do_nonshared;
87 unsigned int vm_segtype;
88 struct qrange range[6];
89 int segcnt;
90 struct resource *res;
93 static DEFINE_MUTEX(dcss_lock);
94 static LIST_HEAD(dcss_list);
95 static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
96 "EW/EN-MIXED" };
97 static int loadshr_scode, loadnsr_scode;
98 static int segext_scode, purgeseg_scode;
99 static int scode_set;
101 /* set correct Diag x'64' subcodes. */
102 static int
103 dcss_set_subcodes(void)
105 char *name = kmalloc(8 * sizeof(char), GFP_KERNEL | GFP_DMA);
106 unsigned long rx, ry;
107 int rc;
109 if (name == NULL)
110 return -ENOMEM;
112 rx = (unsigned long) name;
113 ry = DCSS_FINDSEGX;
115 strcpy(name, "dummy");
116 diag_stat_inc(DIAG_STAT_X064);
117 asm volatile(
118 " diag %0,%1,0x64\n"
119 "0: ipm %2\n"
120 " srl %2,28\n"
121 " j 2f\n"
122 "1: la %2,3\n"
123 "2:\n"
124 EX_TABLE(0b, 1b)
125 : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc", "memory");
127 kfree(name);
128 /* Diag x'64' new subcodes are supported, set to new subcodes */
129 if (rc != 3) {
130 loadshr_scode = DCSS_LOADSHRX;
131 loadnsr_scode = DCSS_LOADNSRX;
132 purgeseg_scode = DCSS_PURGESEG;
133 segext_scode = DCSS_SEGEXTX;
134 return 0;
136 /* Diag x'64' new subcodes are not supported, set to old subcodes */
137 loadshr_scode = DCSS_LOADNOLY;
138 loadnsr_scode = DCSS_LOADNSR;
139 purgeseg_scode = DCSS_PURGESEG;
140 segext_scode = DCSS_SEGEXT;
141 return 0;
145 * Create the 8 bytes, ebcdic VM segment name from
146 * an ascii name.
148 static void
149 dcss_mkname(char *name, char *dcss_name)
151 int i;
153 for (i = 0; i < 8; i++) {
154 if (name[i] == '\0')
155 break;
156 dcss_name[i] = toupper(name[i]);
158 for (; i < 8; i++)
159 dcss_name[i] = ' ';
160 ASCEBC(dcss_name, 8);
165 * search all segments in dcss_list, and return the one
166 * namend *name. If not found, return NULL.
168 static struct dcss_segment *
169 segment_by_name (char *name)
171 char dcss_name[9];
172 struct list_head *l;
173 struct dcss_segment *tmp, *retval = NULL;
175 BUG_ON(!mutex_is_locked(&dcss_lock));
176 dcss_mkname (name, dcss_name);
177 list_for_each (l, &dcss_list) {
178 tmp = list_entry (l, struct dcss_segment, list);
179 if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
180 retval = tmp;
181 break;
184 return retval;
189 * Perform a function on a dcss segment.
191 static inline int
192 dcss_diag(int *func, void *parameter,
193 unsigned long *ret1, unsigned long *ret2)
195 unsigned long rx, ry;
196 int rc;
198 if (scode_set == 0) {
199 rc = dcss_set_subcodes();
200 if (rc < 0)
201 return rc;
202 scode_set = 1;
204 rx = (unsigned long) parameter;
205 ry = (unsigned long) *func;
207 /* 64-bit Diag x'64' new subcode, keep in 64-bit addressing mode */
208 diag_stat_inc(DIAG_STAT_X064);
209 if (*func > DCSS_SEGEXT)
210 asm volatile(
211 " diag %0,%1,0x64\n"
212 " ipm %2\n"
213 " srl %2,28\n"
214 : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
215 /* 31-bit Diag x'64' old subcode, switch to 31-bit addressing mode */
216 else
217 asm volatile(
218 " sam31\n"
219 " diag %0,%1,0x64\n"
220 " sam64\n"
221 " ipm %2\n"
222 " srl %2,28\n"
223 : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
224 *ret1 = rx;
225 *ret2 = ry;
226 return rc;
229 static inline int
230 dcss_diag_translate_rc (int vm_rc) {
231 if (vm_rc == 44)
232 return -ENOENT;
233 return -EIO;
237 /* do a diag to get info about a segment.
238 * fills start_address, end and vm_segtype fields
240 static int
241 query_segment_type (struct dcss_segment *seg)
243 unsigned long dummy, vmrc;
244 int diag_cc, rc, i;
245 struct qout64 *qout;
246 struct qin64 *qin;
248 qin = kmalloc(sizeof(*qin), GFP_KERNEL | GFP_DMA);
249 qout = kmalloc(sizeof(*qout), GFP_KERNEL | GFP_DMA);
250 if ((qin == NULL) || (qout == NULL)) {
251 rc = -ENOMEM;
252 goto out_free;
255 /* initialize diag input parameters */
256 qin->qopcode = DCSS_FINDSEGA;
257 qin->qoutptr = (unsigned long) qout;
258 qin->qoutlen = sizeof(struct qout64);
259 memcpy (qin->qname, seg->dcss_name, 8);
261 diag_cc = dcss_diag(&segext_scode, qin, &dummy, &vmrc);
263 if (diag_cc < 0) {
264 rc = diag_cc;
265 goto out_free;
267 if (diag_cc > 1) {
268 pr_warn("Querying a DCSS type failed with rc=%ld\n", vmrc);
269 rc = dcss_diag_translate_rc (vmrc);
270 goto out_free;
273 /* Only old format of output area of Diagnose x'64' is supported,
274 copy data for the new format. */
275 if (segext_scode == DCSS_SEGEXT) {
276 struct qout64_old *qout_old;
277 qout_old = kzalloc(sizeof(*qout_old), GFP_KERNEL | GFP_DMA);
278 if (qout_old == NULL) {
279 rc = -ENOMEM;
280 goto out_free;
282 memcpy(qout_old, qout, sizeof(struct qout64_old));
283 qout->segstart = (unsigned long) qout_old->segstart;
284 qout->segend = (unsigned long) qout_old->segend;
285 qout->segcnt = qout_old->segcnt;
286 qout->segrcnt = qout_old->segrcnt;
288 if (qout->segcnt > 6)
289 qout->segrcnt = 6;
290 for (i = 0; i < qout->segrcnt; i++) {
291 qout->range[i].start =
292 (unsigned long) qout_old->range[i].start;
293 qout->range[i].end =
294 (unsigned long) qout_old->range[i].end;
296 kfree(qout_old);
298 if (qout->segcnt > 6) {
299 rc = -EOPNOTSUPP;
300 goto out_free;
303 if (qout->segcnt == 1) {
304 seg->vm_segtype = qout->range[0].start & 0xff;
305 } else {
306 /* multi-part segment. only one type supported here:
307 - all parts are contiguous
308 - all parts are either EW or EN type
309 - maximum 6 parts allowed */
310 unsigned long start = qout->segstart >> PAGE_SHIFT;
311 for (i=0; i<qout->segcnt; i++) {
312 if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
313 ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
314 rc = -EOPNOTSUPP;
315 goto out_free;
317 if (start != qout->range[i].start >> PAGE_SHIFT) {
318 rc = -EOPNOTSUPP;
319 goto out_free;
321 start = (qout->range[i].end >> PAGE_SHIFT) + 1;
323 seg->vm_segtype = SEG_TYPE_EWEN;
326 /* analyze diag output and update seg */
327 seg->start_addr = qout->segstart;
328 seg->end = qout->segend;
330 memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
331 seg->segcnt = qout->segcnt;
333 rc = 0;
335 out_free:
336 kfree(qin);
337 kfree(qout);
338 return rc;
342 * get info about a segment
343 * possible return values:
344 * -ENOSYS : we are not running on VM
345 * -EIO : could not perform query diagnose
346 * -ENOENT : no such segment
347 * -EOPNOTSUPP: multi-part segment cannot be used with linux
348 * -ENOMEM : out of memory
349 * 0 .. 6 : type of segment as defined in include/asm-s390/extmem.h
352 segment_type (char* name)
354 int rc;
355 struct dcss_segment seg;
357 if (!MACHINE_IS_VM)
358 return -ENOSYS;
360 dcss_mkname(name, seg.dcss_name);
361 rc = query_segment_type (&seg);
362 if (rc < 0)
363 return rc;
364 return seg.vm_segtype;
368 * check if segment collides with other segments that are currently loaded
369 * returns 1 if this is the case, 0 if no collision was found
371 static int
372 segment_overlaps_others (struct dcss_segment *seg)
374 struct list_head *l;
375 struct dcss_segment *tmp;
377 BUG_ON(!mutex_is_locked(&dcss_lock));
378 list_for_each(l, &dcss_list) {
379 tmp = list_entry(l, struct dcss_segment, list);
380 if ((tmp->start_addr >> 20) > (seg->end >> 20))
381 continue;
382 if ((tmp->end >> 20) < (seg->start_addr >> 20))
383 continue;
384 if (seg == tmp)
385 continue;
386 return 1;
388 return 0;
392 * real segment loading function, called from segment_load
394 static int
395 __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
397 unsigned long start_addr, end_addr, dummy;
398 struct dcss_segment *seg;
399 int rc, diag_cc;
401 start_addr = end_addr = 0;
402 seg = kmalloc(sizeof(*seg), GFP_KERNEL | GFP_DMA);
403 if (seg == NULL) {
404 rc = -ENOMEM;
405 goto out;
407 dcss_mkname (name, seg->dcss_name);
408 rc = query_segment_type (seg);
409 if (rc < 0)
410 goto out_free;
412 if (loadshr_scode == DCSS_LOADSHRX) {
413 if (segment_overlaps_others(seg)) {
414 rc = -EBUSY;
415 goto out_free;
419 rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
421 if (rc)
422 goto out_free;
424 seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
425 if (seg->res == NULL) {
426 rc = -ENOMEM;
427 goto out_shared;
429 seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
430 seg->res->start = seg->start_addr;
431 seg->res->end = seg->end;
432 memcpy(&seg->res_name, seg->dcss_name, 8);
433 EBCASC(seg->res_name, 8);
434 seg->res_name[8] = '\0';
435 strncat(seg->res_name, " (DCSS)", 7);
436 seg->res->name = seg->res_name;
437 rc = seg->vm_segtype;
438 if (rc == SEG_TYPE_SC ||
439 ((rc == SEG_TYPE_SR || rc == SEG_TYPE_ER) && !do_nonshared))
440 seg->res->flags |= IORESOURCE_READONLY;
441 if (request_resource(&iomem_resource, seg->res)) {
442 rc = -EBUSY;
443 kfree(seg->res);
444 goto out_shared;
447 if (do_nonshared)
448 diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
449 &start_addr, &end_addr);
450 else
451 diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
452 &start_addr, &end_addr);
453 if (diag_cc < 0) {
454 dcss_diag(&purgeseg_scode, seg->dcss_name,
455 &dummy, &dummy);
456 rc = diag_cc;
457 goto out_resource;
459 if (diag_cc > 1) {
460 pr_warn("Loading DCSS %s failed with rc=%ld\n", name, end_addr);
461 rc = dcss_diag_translate_rc(end_addr);
462 dcss_diag(&purgeseg_scode, seg->dcss_name,
463 &dummy, &dummy);
464 goto out_resource;
466 seg->start_addr = start_addr;
467 seg->end = end_addr;
468 seg->do_nonshared = do_nonshared;
469 atomic_set(&seg->ref_count, 1);
470 list_add(&seg->list, &dcss_list);
471 *addr = seg->start_addr;
472 *end = seg->end;
473 if (do_nonshared)
474 pr_info("DCSS %s of range %p to %p and type %s loaded as "
475 "exclusive-writable\n", name, (void*) seg->start_addr,
476 (void*) seg->end, segtype_string[seg->vm_segtype]);
477 else {
478 pr_info("DCSS %s of range %p to %p and type %s loaded in "
479 "shared access mode\n", name, (void*) seg->start_addr,
480 (void*) seg->end, segtype_string[seg->vm_segtype]);
482 goto out;
483 out_resource:
484 release_resource(seg->res);
485 kfree(seg->res);
486 out_shared:
487 vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
488 out_free:
489 kfree(seg);
490 out:
491 return rc;
495 * this function loads a DCSS segment
496 * name : name of the DCSS
497 * do_nonshared : 0 indicates that the dcss should be shared with other linux images
498 * 1 indicates that the dcss should be exclusive for this linux image
499 * addr : will be filled with start address of the segment
500 * end : will be filled with end address of the segment
501 * return values:
502 * -ENOSYS : we are not running on VM
503 * -EIO : could not perform query or load diagnose
504 * -ENOENT : no such segment
505 * -EOPNOTSUPP: multi-part segment cannot be used with linux
506 * -ENOSPC : segment cannot be used (overlaps with storage)
507 * -EBUSY : segment can temporarily not be used (overlaps with dcss)
508 * -ERANGE : segment cannot be used (exceeds kernel mapping range)
509 * -EPERM : segment is currently loaded with incompatible permissions
510 * -ENOMEM : out of memory
511 * 0 .. 6 : type of segment as defined in include/asm-s390/extmem.h
514 segment_load (char *name, int do_nonshared, unsigned long *addr,
515 unsigned long *end)
517 struct dcss_segment *seg;
518 int rc;
520 if (!MACHINE_IS_VM)
521 return -ENOSYS;
523 mutex_lock(&dcss_lock);
524 seg = segment_by_name (name);
525 if (seg == NULL)
526 rc = __segment_load (name, do_nonshared, addr, end);
527 else {
528 if (do_nonshared == seg->do_nonshared) {
529 atomic_inc(&seg->ref_count);
530 *addr = seg->start_addr;
531 *end = seg->end;
532 rc = seg->vm_segtype;
533 } else {
534 *addr = *end = 0;
535 rc = -EPERM;
538 mutex_unlock(&dcss_lock);
539 return rc;
543 * this function modifies the shared state of a DCSS segment. note that
544 * name : name of the DCSS
545 * do_nonshared : 0 indicates that the dcss should be shared with other linux images
546 * 1 indicates that the dcss should be exclusive for this linux image
547 * return values:
548 * -EIO : could not perform load diagnose (segment gone!)
549 * -ENOENT : no such segment (segment gone!)
550 * -EAGAIN : segment is in use by other exploiters, try later
551 * -EINVAL : no segment with the given name is currently loaded - name invalid
552 * -EBUSY : segment can temporarily not be used (overlaps with dcss)
553 * 0 : operation succeeded
556 segment_modify_shared (char *name, int do_nonshared)
558 struct dcss_segment *seg;
559 unsigned long start_addr, end_addr, dummy;
560 int rc, diag_cc;
562 start_addr = end_addr = 0;
563 mutex_lock(&dcss_lock);
564 seg = segment_by_name (name);
565 if (seg == NULL) {
566 rc = -EINVAL;
567 goto out_unlock;
569 if (do_nonshared == seg->do_nonshared) {
570 pr_info("DCSS %s is already in the requested access "
571 "mode\n", name);
572 rc = 0;
573 goto out_unlock;
575 if (atomic_read (&seg->ref_count) != 1) {
576 pr_warn("DCSS %s is in use and cannot be reloaded\n", name);
577 rc = -EAGAIN;
578 goto out_unlock;
580 release_resource(seg->res);
581 if (do_nonshared)
582 seg->res->flags &= ~IORESOURCE_READONLY;
583 else
584 if (seg->vm_segtype == SEG_TYPE_SR ||
585 seg->vm_segtype == SEG_TYPE_ER)
586 seg->res->flags |= IORESOURCE_READONLY;
588 if (request_resource(&iomem_resource, seg->res)) {
589 pr_warn("DCSS %s overlaps with used memory resources and cannot be reloaded\n",
590 name);
591 rc = -EBUSY;
592 kfree(seg->res);
593 goto out_del_mem;
596 dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
597 if (do_nonshared)
598 diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
599 &start_addr, &end_addr);
600 else
601 diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
602 &start_addr, &end_addr);
603 if (diag_cc < 0) {
604 rc = diag_cc;
605 goto out_del_res;
607 if (diag_cc > 1) {
608 pr_warn("Reloading DCSS %s failed with rc=%ld\n",
609 name, end_addr);
610 rc = dcss_diag_translate_rc(end_addr);
611 goto out_del_res;
613 seg->start_addr = start_addr;
614 seg->end = end_addr;
615 seg->do_nonshared = do_nonshared;
616 rc = 0;
617 goto out_unlock;
618 out_del_res:
619 release_resource(seg->res);
620 kfree(seg->res);
621 out_del_mem:
622 vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
623 list_del(&seg->list);
624 dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
625 kfree(seg);
626 out_unlock:
627 mutex_unlock(&dcss_lock);
628 return rc;
632 * Decrease the use count of a DCSS segment and remove
633 * it from the address space if nobody is using it
634 * any longer.
636 void
637 segment_unload(char *name)
639 unsigned long dummy;
640 struct dcss_segment *seg;
642 if (!MACHINE_IS_VM)
643 return;
645 mutex_lock(&dcss_lock);
646 seg = segment_by_name (name);
647 if (seg == NULL) {
648 pr_err("Unloading unknown DCSS %s failed\n", name);
649 goto out_unlock;
651 if (atomic_dec_return(&seg->ref_count) != 0)
652 goto out_unlock;
653 release_resource(seg->res);
654 kfree(seg->res);
655 vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
656 list_del(&seg->list);
657 dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
658 kfree(seg);
659 out_unlock:
660 mutex_unlock(&dcss_lock);
664 * save segment content permanently
666 void
667 segment_save(char *name)
669 struct dcss_segment *seg;
670 char cmd1[160];
671 char cmd2[80];
672 int i, response;
674 if (!MACHINE_IS_VM)
675 return;
677 mutex_lock(&dcss_lock);
678 seg = segment_by_name (name);
680 if (seg == NULL) {
681 pr_err("Saving unknown DCSS %s failed\n", name);
682 goto out;
685 sprintf(cmd1, "DEFSEG %s", name);
686 for (i=0; i<seg->segcnt; i++) {
687 sprintf(cmd1+strlen(cmd1), " %lX-%lX %s",
688 seg->range[i].start >> PAGE_SHIFT,
689 seg->range[i].end >> PAGE_SHIFT,
690 segtype_string[seg->range[i].start & 0xff]);
692 sprintf(cmd2, "SAVESEG %s", name);
693 response = 0;
694 cpcmd(cmd1, NULL, 0, &response);
695 if (response) {
696 pr_err("Saving a DCSS failed with DEFSEG response code "
697 "%i\n", response);
698 goto out;
700 cpcmd(cmd2, NULL, 0, &response);
701 if (response) {
702 pr_err("Saving a DCSS failed with SAVESEG response code "
703 "%i\n", response);
704 goto out;
706 out:
707 mutex_unlock(&dcss_lock);
711 * print appropriate error message for segment_load()/segment_type()
712 * return code
714 void segment_warning(int rc, char *seg_name)
716 switch (rc) {
717 case -ENOENT:
718 pr_err("DCSS %s cannot be loaded or queried\n", seg_name);
719 break;
720 case -ENOSYS:
721 pr_err("DCSS %s cannot be loaded or queried without "
722 "z/VM\n", seg_name);
723 break;
724 case -EIO:
725 pr_err("Loading or querying DCSS %s resulted in a "
726 "hardware error\n", seg_name);
727 break;
728 case -EOPNOTSUPP:
729 pr_err("DCSS %s has multiple page ranges and cannot be "
730 "loaded or queried\n", seg_name);
731 break;
732 case -ENOSPC:
733 pr_err("DCSS %s overlaps with used storage and cannot "
734 "be loaded\n", seg_name);
735 break;
736 case -EBUSY:
737 pr_err("%s needs used memory resources and cannot be "
738 "loaded or queried\n", seg_name);
739 break;
740 case -EPERM:
741 pr_err("DCSS %s is already loaded in a different access "
742 "mode\n", seg_name);
743 break;
744 case -ENOMEM:
745 pr_err("There is not enough memory to load or query "
746 "DCSS %s\n", seg_name);
747 break;
748 case -ERANGE:
749 pr_err("DCSS %s exceeds the kernel mapping range (%lu) "
750 "and cannot be loaded\n", seg_name, VMEM_MAX_PHYS);
751 break;
752 default:
753 break;
757 EXPORT_SYMBOL(segment_load);
758 EXPORT_SYMBOL(segment_unload);
759 EXPORT_SYMBOL(segment_save);
760 EXPORT_SYMBOL(segment_type);
761 EXPORT_SYMBOL(segment_modify_shared);
762 EXPORT_SYMBOL(segment_warning);