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v4.6
 
  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 */
  8
  9#define KMSG_COMPONENT "extmem"
 10#define pr_fmt(fmt) KMSG_COMPONENT ": " 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/module.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>
 29
 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
 41
 42struct qrange {
 43	unsigned long  start; /* last byte type */
 44	unsigned long  end;   /* last byte reserved */
 45};
 46
 47struct qout64 {
 48	unsigned long segstart;
 49	unsigned long segend;
 50	int segcnt;
 51	int segrcnt;
 52	struct qrange range[6];
 53};
 54
 55struct qrange_old {
 56	unsigned int start; /* last byte type */
 57	unsigned int end;   /* last byte reserved */
 58};
 59
 60/* output area format for the Diag x'64' old subcode x'18' */
 61struct qout64_old {
 62	int segstart;
 63	int segend;
 64	int segcnt;
 65	int segrcnt;
 66	struct qrange_old range[6];
 67};
 68
 69struct 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;
 77};
 78
 79struct 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;
 91};
 92
 93static DEFINE_MUTEX(dcss_lock);
 94static LIST_HEAD(dcss_list);
 95static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
 96					"EW/EN-MIXED" };
 97static int loadshr_scode, loadnsr_scode;
 98static int segext_scode, purgeseg_scode;
 99static int scode_set;
100
101/* set correct Diag x'64' subcodes. */
102static int
103dcss_set_subcodes(void)
104{
105	char *name = kmalloc(8 * sizeof(char), GFP_KERNEL | GFP_DMA);
106	unsigned long rx, ry;
107	int rc;
108
109	if (name == NULL)
110		return -ENOMEM;
111
112	rx = (unsigned long) name;
113	ry = DCSS_FINDSEGX;
114
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");
126
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;
135	}
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;
142}
143
144/*
145 * Create the 8 bytes, ebcdic VM segment name from
146 * an ascii name.
147 */
148static void
149dcss_mkname(char *name, char *dcss_name)
150{
151	int i;
152
153	for (i = 0; i < 8; i++) {
154		if (name[i] == '\0')
155			break;
156		dcss_name[i] = toupper(name[i]);
157	};
158	for (; i < 8; i++)
159		dcss_name[i] = ' ';
160	ASCEBC(dcss_name, 8);
161}
162
163
164/*
165 * search all segments in dcss_list, and return the one
166 * namend *name. If not found, return NULL.
167 */
168static struct dcss_segment *
169segment_by_name (char *name)
170{
171	char dcss_name[9];
172	struct list_head *l;
173	struct dcss_segment *tmp, *retval = NULL;
174
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;
182		}
183	}
184	return retval;
185}
186
187
188/*
189 * Perform a function on a dcss segment.
190 */
191static inline int
192dcss_diag(int *func, void *parameter,
193           unsigned long *ret1, unsigned long *ret2)
194{
195	unsigned long rx, ry;
196	int rc;
197
198	if (scode_set == 0) {
199		rc = dcss_set_subcodes();
200		if (rc < 0)
201			return rc;
202		scode_set = 1;
203	}
204	rx = (unsigned long) parameter;
205	ry = (unsigned long) *func;
206
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;
227}
228
229static inline int
230dcss_diag_translate_rc (int vm_rc) {
231	if (vm_rc == 44)
232		return -ENOENT;
233	return -EIO;
234}
235
236
237/* do a diag to get info about a segment.
238 * fills start_address, end and vm_segtype fields
239 */
240static int
241query_segment_type (struct dcss_segment *seg)
242{
243	unsigned long dummy, vmrc;
244	int diag_cc, rc, i;
245	struct qout64 *qout;
246	struct qin64 *qin;
247
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;
253	}
254
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);
260
261	diag_cc = dcss_diag(&segext_scode, qin, &dummy, &vmrc);
262
263	if (diag_cc < 0) {
264		rc = diag_cc;
265		goto out_free;
266	}
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;
271	}
272
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;
281		}
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;
287
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;
295		}
296		kfree(qout_old);
297	}
298	if (qout->segcnt > 6) {
299		rc = -EOPNOTSUPP;
300		goto out_free;
301	}
302
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;
316			}
317			if (start != qout->range[i].start >> PAGE_SHIFT) {
318				rc = -EOPNOTSUPP;
319				goto out_free;
320			}
321			start = (qout->range[i].end >> PAGE_SHIFT) + 1;
322		}
323		seg->vm_segtype = SEG_TYPE_EWEN;
324	}
325
326	/* analyze diag output and update seg */
327	seg->start_addr = qout->segstart;
328	seg->end = qout->segend;
329
330	memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
331	seg->segcnt = qout->segcnt;
332
333	rc = 0;
334
335 out_free:
336	kfree(qin);
337	kfree(qout);
338	return rc;
339}
340
341/*
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
350 */
351int
352segment_type (char* name)
353{
354	int rc;
355	struct dcss_segment seg;
356
357	if (!MACHINE_IS_VM)
358		return -ENOSYS;
359
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;
365}
366
367/*
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
370 */
371static int
372segment_overlaps_others (struct dcss_segment *seg)
373{
374	struct list_head *l;
375	struct dcss_segment *tmp;
376
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;
387	}
388	return 0;
389}
390
391/*
392 * real segment loading function, called from segment_load
393 */
394static int
395__segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
396{
397	unsigned long start_addr, end_addr, dummy;
398	struct dcss_segment *seg;
399	int rc, diag_cc;
400
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;
406	}
407	dcss_mkname (name, seg->dcss_name);
408	rc = query_segment_type (seg);
409	if (rc < 0)
410		goto out_free;
411
412	if (loadshr_scode == DCSS_LOADSHRX) {
413		if (segment_overlaps_others(seg)) {
414			rc = -EBUSY;
415			goto out_free;
416		}
417	}
418
419	rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
420
421	if (rc)
422		goto out_free;
423
424	seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
425	if (seg->res == NULL) {
426		rc = -ENOMEM;
427		goto out_shared;
428	}
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;
445	}
446
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;
458	}
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;
465	}
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]);
481	}
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;
492}
493
494/*
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
512 */
513int
514segment_load (char *name, int do_nonshared, unsigned long *addr,
515		unsigned long *end)
516{
517	struct dcss_segment *seg;
518	int rc;
519
520	if (!MACHINE_IS_VM)
521		return -ENOSYS;
522
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;
536		}
537	}
538	mutex_unlock(&dcss_lock);
539	return rc;
540}
541
542/*
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
554 */
555int
556segment_modify_shared (char *name, int do_nonshared)
557{
558	struct dcss_segment *seg;
559	unsigned long start_addr, end_addr, dummy;
560	int rc, diag_cc;
561
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;
568	}
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;
574	}
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;
579	}
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;
587
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;
594	}
595
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;
606	}
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;
612	}
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;
629}
630
631/*
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.
635 */
636void
637segment_unload(char *name)
638{
639	unsigned long dummy;
640	struct dcss_segment *seg;
641
642	if (!MACHINE_IS_VM)
643		return;
644
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;
650	}
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);
659out_unlock:
660	mutex_unlock(&dcss_lock);
661}
662
663/*
664 * save segment content permanently
665 */
666void
667segment_save(char *name)
668{
669	struct dcss_segment *seg;
670	char cmd1[160];
671	char cmd2[80];
672	int i, response;
673
674	if (!MACHINE_IS_VM)
675		return;
676
677	mutex_lock(&dcss_lock);
678	seg = segment_by_name (name);
679
680	if (seg == NULL) {
681		pr_err("Saving unknown DCSS %s failed\n", name);
682		goto out;
683	}
684
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]);
691	}
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;
699	}
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;
705	}
706out:
707	mutex_unlock(&dcss_lock);
708}
709
710/*
711 * print appropriate error message for segment_load()/segment_type()
712 * return code
713 */
714void segment_warning(int rc, char *seg_name)
715{
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;
754	}
755}
756
757EXPORT_SYMBOL(segment_load);
758EXPORT_SYMBOL(segment_unload);
759EXPORT_SYMBOL(segment_save);
760EXPORT_SYMBOL(segment_type);
761EXPORT_SYMBOL(segment_modify_shared);
762EXPORT_SYMBOL(segment_warning);
v4.17
  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/bootmem.h>
 20#include <linux/ctype.h>
 21#include <linux/ioport.h>
 22#include <asm/diag.h>
 23#include <asm/page.h>
 24#include <asm/pgtable.h>
 25#include <asm/ebcdic.h>
 26#include <asm/errno.h>
 27#include <asm/extmem.h>
 28#include <asm/cpcmd.h>
 29#include <asm/setup.h>
 30
 31#define DCSS_LOADSHR    0x00
 32#define DCSS_LOADNSR    0x04
 33#define DCSS_PURGESEG   0x08
 34#define DCSS_FINDSEG    0x0c
 35#define DCSS_LOADNOLY   0x10
 36#define DCSS_SEGEXT     0x18
 37#define DCSS_LOADSHRX	0x20
 38#define DCSS_LOADNSRX	0x24
 39#define DCSS_FINDSEGX	0x2c
 40#define DCSS_SEGEXTX	0x38
 41#define DCSS_FINDSEGA   0x0c
 42
 43struct qrange {
 44	unsigned long  start; /* last byte type */
 45	unsigned long  end;   /* last byte reserved */
 46};
 47
 48struct qout64 {
 49	unsigned long segstart;
 50	unsigned long segend;
 51	int segcnt;
 52	int segrcnt;
 53	struct qrange range[6];
 54};
 55
 56struct qrange_old {
 57	unsigned int start; /* last byte type */
 58	unsigned int end;   /* last byte reserved */
 59};
 60
 61/* output area format for the Diag x'64' old subcode x'18' */
 62struct qout64_old {
 63	int segstart;
 64	int segend;
 65	int segcnt;
 66	int segrcnt;
 67	struct qrange_old range[6];
 68};
 69
 70struct qin64 {
 71	char qopcode;
 72	char rsrv1[3];
 73	char qrcode;
 74	char rsrv2[3];
 75	char qname[8];
 76	unsigned int qoutptr;
 77	short int qoutlen;
 78};
 79
 80struct dcss_segment {
 81	struct list_head list;
 82	char dcss_name[8];
 83	char res_name[15];
 84	unsigned long start_addr;
 85	unsigned long end;
 86	atomic_t ref_count;
 87	int do_nonshared;
 88	unsigned int vm_segtype;
 89	struct qrange range[6];
 90	int segcnt;
 91	struct resource *res;
 92};
 93
 94static DEFINE_MUTEX(dcss_lock);
 95static LIST_HEAD(dcss_list);
 96static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
 97					"EW/EN-MIXED" };
 98static int loadshr_scode, loadnsr_scode;
 99static int segext_scode, purgeseg_scode;
100static int scode_set;
101
102/* set correct Diag x'64' subcodes. */
103static int
104dcss_set_subcodes(void)
105{
106	char *name = kmalloc(8 * sizeof(char), GFP_KERNEL | GFP_DMA);
107	unsigned long rx, ry;
108	int rc;
109
110	if (name == NULL)
111		return -ENOMEM;
112
113	rx = (unsigned long) name;
114	ry = DCSS_FINDSEGX;
115
116	strcpy(name, "dummy");
117	diag_stat_inc(DIAG_STAT_X064);
118	asm volatile(
119		"	diag	%0,%1,0x64\n"
120		"0:	ipm	%2\n"
121		"	srl	%2,28\n"
122		"	j	2f\n"
123		"1:	la	%2,3\n"
124		"2:\n"
125		EX_TABLE(0b, 1b)
126		: "+d" (rx), "+d" (ry), "=d" (rc) : : "cc", "memory");
127
128	kfree(name);
129	/* Diag x'64' new subcodes are supported, set to new subcodes */
130	if (rc != 3) {
131		loadshr_scode = DCSS_LOADSHRX;
132		loadnsr_scode = DCSS_LOADNSRX;
133		purgeseg_scode = DCSS_PURGESEG;
134		segext_scode = DCSS_SEGEXTX;
135		return 0;
136	}
137	/* Diag x'64' new subcodes are not supported, set to old subcodes */
138	loadshr_scode = DCSS_LOADNOLY;
139	loadnsr_scode = DCSS_LOADNSR;
140	purgeseg_scode = DCSS_PURGESEG;
141	segext_scode = DCSS_SEGEXT;
142	return 0;
143}
144
145/*
146 * Create the 8 bytes, ebcdic VM segment name from
147 * an ascii name.
148 */
149static void
150dcss_mkname(char *name, char *dcss_name)
151{
152	int i;
153
154	for (i = 0; i < 8; i++) {
155		if (name[i] == '\0')
156			break;
157		dcss_name[i] = toupper(name[i]);
158	}
159	for (; i < 8; i++)
160		dcss_name[i] = ' ';
161	ASCEBC(dcss_name, 8);
162}
163
164
165/*
166 * search all segments in dcss_list, and return the one
167 * namend *name. If not found, return NULL.
168 */
169static struct dcss_segment *
170segment_by_name (char *name)
171{
172	char dcss_name[9];
173	struct list_head *l;
174	struct dcss_segment *tmp, *retval = NULL;
175
176	BUG_ON(!mutex_is_locked(&dcss_lock));
177	dcss_mkname (name, dcss_name);
178	list_for_each (l, &dcss_list) {
179		tmp = list_entry (l, struct dcss_segment, list);
180		if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
181			retval = tmp;
182			break;
183		}
184	}
185	return retval;
186}
187
188
189/*
190 * Perform a function on a dcss segment.
191 */
192static inline int
193dcss_diag(int *func, void *parameter,
194           unsigned long *ret1, unsigned long *ret2)
195{
196	unsigned long rx, ry;
197	int rc;
198
199	if (scode_set == 0) {
200		rc = dcss_set_subcodes();
201		if (rc < 0)
202			return rc;
203		scode_set = 1;
204	}
205	rx = (unsigned long) parameter;
206	ry = (unsigned long) *func;
207
208	/* 64-bit Diag x'64' new subcode, keep in 64-bit addressing mode */
209	diag_stat_inc(DIAG_STAT_X064);
210	if (*func > DCSS_SEGEXT)
211		asm volatile(
212			"	diag	%0,%1,0x64\n"
213			"	ipm	%2\n"
214			"	srl	%2,28\n"
215			: "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
216	/* 31-bit Diag x'64' old subcode, switch to 31-bit addressing mode */
217	else
218		asm volatile(
219			"	sam31\n"
220			"	diag	%0,%1,0x64\n"
221			"	sam64\n"
222			"	ipm	%2\n"
223			"	srl	%2,28\n"
224			: "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
225	*ret1 = rx;
226	*ret2 = ry;
227	return rc;
228}
229
230static inline int
231dcss_diag_translate_rc (int vm_rc) {
232	if (vm_rc == 44)
233		return -ENOENT;
234	return -EIO;
235}
236
237
238/* do a diag to get info about a segment.
239 * fills start_address, end and vm_segtype fields
240 */
241static int
242query_segment_type (struct dcss_segment *seg)
243{
244	unsigned long dummy, vmrc;
245	int diag_cc, rc, i;
246	struct qout64 *qout;
247	struct qin64 *qin;
248
249	qin = kmalloc(sizeof(*qin), GFP_KERNEL | GFP_DMA);
250	qout = kmalloc(sizeof(*qout), GFP_KERNEL | GFP_DMA);
251	if ((qin == NULL) || (qout == NULL)) {
252		rc = -ENOMEM;
253		goto out_free;
254	}
255
256	/* initialize diag input parameters */
257	qin->qopcode = DCSS_FINDSEGA;
258	qin->qoutptr = (unsigned long) qout;
259	qin->qoutlen = sizeof(struct qout64);
260	memcpy (qin->qname, seg->dcss_name, 8);
261
262	diag_cc = dcss_diag(&segext_scode, qin, &dummy, &vmrc);
263
264	if (diag_cc < 0) {
265		rc = diag_cc;
266		goto out_free;
267	}
268	if (diag_cc > 1) {
269		pr_warn("Querying a DCSS type failed with rc=%ld\n", vmrc);
270		rc = dcss_diag_translate_rc (vmrc);
271		goto out_free;
272	}
273
274	/* Only old format of output area of Diagnose x'64' is supported,
275	   copy data for the new format. */
276	if (segext_scode == DCSS_SEGEXT) {
277		struct qout64_old *qout_old;
278		qout_old = kzalloc(sizeof(*qout_old), GFP_KERNEL | GFP_DMA);
279		if (qout_old == NULL) {
280			rc = -ENOMEM;
281			goto out_free;
282		}
283		memcpy(qout_old, qout, sizeof(struct qout64_old));
284		qout->segstart = (unsigned long) qout_old->segstart;
285		qout->segend = (unsigned long) qout_old->segend;
286		qout->segcnt = qout_old->segcnt;
287		qout->segrcnt = qout_old->segrcnt;
288
289		if (qout->segcnt > 6)
290			qout->segrcnt = 6;
291		for (i = 0; i < qout->segrcnt; i++) {
292			qout->range[i].start =
293				(unsigned long) qout_old->range[i].start;
294			qout->range[i].end =
295				(unsigned long) qout_old->range[i].end;
296		}
297		kfree(qout_old);
298	}
299	if (qout->segcnt > 6) {
300		rc = -EOPNOTSUPP;
301		goto out_free;
302	}
303
304	if (qout->segcnt == 1) {
305		seg->vm_segtype = qout->range[0].start & 0xff;
306	} else {
307		/* multi-part segment. only one type supported here:
308		    - all parts are contiguous
309		    - all parts are either EW or EN type
310		    - maximum 6 parts allowed */
311		unsigned long start = qout->segstart >> PAGE_SHIFT;
312		for (i=0; i<qout->segcnt; i++) {
313			if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
314			    ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
315				rc = -EOPNOTSUPP;
316				goto out_free;
317			}
318			if (start != qout->range[i].start >> PAGE_SHIFT) {
319				rc = -EOPNOTSUPP;
320				goto out_free;
321			}
322			start = (qout->range[i].end >> PAGE_SHIFT) + 1;
323		}
324		seg->vm_segtype = SEG_TYPE_EWEN;
325	}
326
327	/* analyze diag output and update seg */
328	seg->start_addr = qout->segstart;
329	seg->end = qout->segend;
330
331	memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
332	seg->segcnt = qout->segcnt;
333
334	rc = 0;
335
336 out_free:
337	kfree(qin);
338	kfree(qout);
339	return rc;
340}
341
342/*
343 * get info about a segment
344 * possible return values:
345 * -ENOSYS  : we are not running on VM
346 * -EIO     : could not perform query diagnose
347 * -ENOENT  : no such segment
348 * -EOPNOTSUPP: multi-part segment cannot be used with linux
349 * -ENOMEM  : out of memory
350 * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
351 */
352int
353segment_type (char* name)
354{
355	int rc;
356	struct dcss_segment seg;
357
358	if (!MACHINE_IS_VM)
359		return -ENOSYS;
360
361	dcss_mkname(name, seg.dcss_name);
362	rc = query_segment_type (&seg);
363	if (rc < 0)
364		return rc;
365	return seg.vm_segtype;
366}
367
368/*
369 * check if segment collides with other segments that are currently loaded
370 * returns 1 if this is the case, 0 if no collision was found
371 */
372static int
373segment_overlaps_others (struct dcss_segment *seg)
374{
375	struct list_head *l;
376	struct dcss_segment *tmp;
377
378	BUG_ON(!mutex_is_locked(&dcss_lock));
379	list_for_each(l, &dcss_list) {
380		tmp = list_entry(l, struct dcss_segment, list);
381		if ((tmp->start_addr >> 20) > (seg->end >> 20))
382			continue;
383		if ((tmp->end >> 20) < (seg->start_addr >> 20))
384			continue;
385		if (seg == tmp)
386			continue;
387		return 1;
388	}
389	return 0;
390}
391
392/*
393 * real segment loading function, called from segment_load
394 */
395static int
396__segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
397{
398	unsigned long start_addr, end_addr, dummy;
399	struct dcss_segment *seg;
400	int rc, diag_cc;
401
402	start_addr = end_addr = 0;
403	seg = kmalloc(sizeof(*seg), GFP_KERNEL | GFP_DMA);
404	if (seg == NULL) {
405		rc = -ENOMEM;
406		goto out;
407	}
408	dcss_mkname (name, seg->dcss_name);
409	rc = query_segment_type (seg);
410	if (rc < 0)
411		goto out_free;
412
413	if (loadshr_scode == DCSS_LOADSHRX) {
414		if (segment_overlaps_others(seg)) {
415			rc = -EBUSY;
416			goto out_free;
417		}
418	}
419
420	rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
421
422	if (rc)
423		goto out_free;
424
425	seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
426	if (seg->res == NULL) {
427		rc = -ENOMEM;
428		goto out_shared;
429	}
430	seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
431	seg->res->start = seg->start_addr;
432	seg->res->end = seg->end;
433	memcpy(&seg->res_name, seg->dcss_name, 8);
434	EBCASC(seg->res_name, 8);
435	seg->res_name[8] = '\0';
436	strncat(seg->res_name, " (DCSS)", 7);
437	seg->res->name = seg->res_name;
438	rc = seg->vm_segtype;
439	if (rc == SEG_TYPE_SC ||
440	    ((rc == SEG_TYPE_SR || rc == SEG_TYPE_ER) && !do_nonshared))
441		seg->res->flags |= IORESOURCE_READONLY;
442	if (request_resource(&iomem_resource, seg->res)) {
443		rc = -EBUSY;
444		kfree(seg->res);
445		goto out_shared;
446	}
447
448	if (do_nonshared)
449		diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
450				&start_addr, &end_addr);
451	else
452		diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
453				&start_addr, &end_addr);
454	if (diag_cc < 0) {
455		dcss_diag(&purgeseg_scode, seg->dcss_name,
456				&dummy, &dummy);
457		rc = diag_cc;
458		goto out_resource;
459	}
460	if (diag_cc > 1) {
461		pr_warn("Loading DCSS %s failed with rc=%ld\n", name, end_addr);
462		rc = dcss_diag_translate_rc(end_addr);
463		dcss_diag(&purgeseg_scode, seg->dcss_name,
464				&dummy, &dummy);
465		goto out_resource;
466	}
467	seg->start_addr = start_addr;
468	seg->end = end_addr;
469	seg->do_nonshared = do_nonshared;
470	atomic_set(&seg->ref_count, 1);
471	list_add(&seg->list, &dcss_list);
472	*addr = seg->start_addr;
473	*end  = seg->end;
474	if (do_nonshared)
475		pr_info("DCSS %s of range %p to %p and type %s loaded as "
476			"exclusive-writable\n", name, (void*) seg->start_addr,
477			(void*) seg->end, segtype_string[seg->vm_segtype]);
478	else {
479		pr_info("DCSS %s of range %p to %p and type %s loaded in "
480			"shared access mode\n", name, (void*) seg->start_addr,
481			(void*) seg->end, segtype_string[seg->vm_segtype]);
482	}
483	goto out;
484 out_resource:
485	release_resource(seg->res);
486	kfree(seg->res);
487 out_shared:
488	vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
489 out_free:
490	kfree(seg);
491 out:
492	return rc;
493}
494
495/*
496 * this function loads a DCSS segment
497 * name         : name of the DCSS
498 * do_nonshared : 0 indicates that the dcss should be shared with other linux images
499 *                1 indicates that the dcss should be exclusive for this linux image
500 * addr         : will be filled with start address of the segment
501 * end          : will be filled with end address of the segment
502 * return values:
503 * -ENOSYS  : we are not running on VM
504 * -EIO     : could not perform query or load diagnose
505 * -ENOENT  : no such segment
506 * -EOPNOTSUPP: multi-part segment cannot be used with linux
507 * -ENOSPC  : segment cannot be used (overlaps with storage)
508 * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
509 * -ERANGE  : segment cannot be used (exceeds kernel mapping range)
510 * -EPERM   : segment is currently loaded with incompatible permissions
511 * -ENOMEM  : out of memory
512 * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
513 */
514int
515segment_load (char *name, int do_nonshared, unsigned long *addr,
516		unsigned long *end)
517{
518	struct dcss_segment *seg;
519	int rc;
520
521	if (!MACHINE_IS_VM)
522		return -ENOSYS;
523
524	mutex_lock(&dcss_lock);
525	seg = segment_by_name (name);
526	if (seg == NULL)
527		rc = __segment_load (name, do_nonshared, addr, end);
528	else {
529		if (do_nonshared == seg->do_nonshared) {
530			atomic_inc(&seg->ref_count);
531			*addr = seg->start_addr;
532			*end  = seg->end;
533			rc    = seg->vm_segtype;
534		} else {
535			*addr = *end = 0;
536			rc    = -EPERM;
537		}
538	}
539	mutex_unlock(&dcss_lock);
540	return rc;
541}
542
543/*
544 * this function modifies the shared state of a DCSS segment. note that
545 * name         : name of the DCSS
546 * do_nonshared : 0 indicates that the dcss should be shared with other linux images
547 *                1 indicates that the dcss should be exclusive for this linux image
548 * return values:
549 * -EIO     : could not perform load diagnose (segment gone!)
550 * -ENOENT  : no such segment (segment gone!)
551 * -EAGAIN  : segment is in use by other exploiters, try later
552 * -EINVAL  : no segment with the given name is currently loaded - name invalid
553 * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
554 * 0	    : operation succeeded
555 */
556int
557segment_modify_shared (char *name, int do_nonshared)
558{
559	struct dcss_segment *seg;
560	unsigned long start_addr, end_addr, dummy;
561	int rc, diag_cc;
562
563	start_addr = end_addr = 0;
564	mutex_lock(&dcss_lock);
565	seg = segment_by_name (name);
566	if (seg == NULL) {
567		rc = -EINVAL;
568		goto out_unlock;
569	}
570	if (do_nonshared == seg->do_nonshared) {
571		pr_info("DCSS %s is already in the requested access "
572			"mode\n", name);
573		rc = 0;
574		goto out_unlock;
575	}
576	if (atomic_read (&seg->ref_count) != 1) {
577		pr_warn("DCSS %s is in use and cannot be reloaded\n", name);
578		rc = -EAGAIN;
579		goto out_unlock;
580	}
581	release_resource(seg->res);
582	if (do_nonshared)
583		seg->res->flags &= ~IORESOURCE_READONLY;
584	else
585		if (seg->vm_segtype == SEG_TYPE_SR ||
586		    seg->vm_segtype == SEG_TYPE_ER)
587			seg->res->flags |= IORESOURCE_READONLY;
588
589	if (request_resource(&iomem_resource, seg->res)) {
590		pr_warn("DCSS %s overlaps with used memory resources and cannot be reloaded\n",
591			name);
592		rc = -EBUSY;
593		kfree(seg->res);
594		goto out_del_mem;
595	}
596
597	dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
598	if (do_nonshared)
599		diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
600				&start_addr, &end_addr);
601	else
602		diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
603				&start_addr, &end_addr);
604	if (diag_cc < 0) {
605		rc = diag_cc;
606		goto out_del_res;
607	}
608	if (diag_cc > 1) {
609		pr_warn("Reloading DCSS %s failed with rc=%ld\n",
610			name, end_addr);
611		rc = dcss_diag_translate_rc(end_addr);
612		goto out_del_res;
613	}
614	seg->start_addr = start_addr;
615	seg->end = end_addr;
616	seg->do_nonshared = do_nonshared;
617	rc = 0;
618	goto out_unlock;
619 out_del_res:
620	release_resource(seg->res);
621	kfree(seg->res);
622 out_del_mem:
623	vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
624	list_del(&seg->list);
625	dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
626	kfree(seg);
627 out_unlock:
628	mutex_unlock(&dcss_lock);
629	return rc;
630}
631
632/*
633 * Decrease the use count of a DCSS segment and remove
634 * it from the address space if nobody is using it
635 * any longer.
636 */
637void
638segment_unload(char *name)
639{
640	unsigned long dummy;
641	struct dcss_segment *seg;
642
643	if (!MACHINE_IS_VM)
644		return;
645
646	mutex_lock(&dcss_lock);
647	seg = segment_by_name (name);
648	if (seg == NULL) {
649		pr_err("Unloading unknown DCSS %s failed\n", name);
650		goto out_unlock;
651	}
652	if (atomic_dec_return(&seg->ref_count) != 0)
653		goto out_unlock;
654	release_resource(seg->res);
655	kfree(seg->res);
656	vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
657	list_del(&seg->list);
658	dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
659	kfree(seg);
660out_unlock:
661	mutex_unlock(&dcss_lock);
662}
663
664/*
665 * save segment content permanently
666 */
667void
668segment_save(char *name)
669{
670	struct dcss_segment *seg;
671	char cmd1[160];
672	char cmd2[80];
673	int i, response;
674
675	if (!MACHINE_IS_VM)
676		return;
677
678	mutex_lock(&dcss_lock);
679	seg = segment_by_name (name);
680
681	if (seg == NULL) {
682		pr_err("Saving unknown DCSS %s failed\n", name);
683		goto out;
684	}
685
686	sprintf(cmd1, "DEFSEG %s", name);
687	for (i=0; i<seg->segcnt; i++) {
688		sprintf(cmd1+strlen(cmd1), " %lX-%lX %s",
689			seg->range[i].start >> PAGE_SHIFT,
690			seg->range[i].end >> PAGE_SHIFT,
691			segtype_string[seg->range[i].start & 0xff]);
692	}
693	sprintf(cmd2, "SAVESEG %s", name);
694	response = 0;
695	cpcmd(cmd1, NULL, 0, &response);
696	if (response) {
697		pr_err("Saving a DCSS failed with DEFSEG response code "
698		       "%i\n", response);
699		goto out;
700	}
701	cpcmd(cmd2, NULL, 0, &response);
702	if (response) {
703		pr_err("Saving a DCSS failed with SAVESEG response code "
704		       "%i\n", response);
705		goto out;
706	}
707out:
708	mutex_unlock(&dcss_lock);
709}
710
711/*
712 * print appropriate error message for segment_load()/segment_type()
713 * return code
714 */
715void segment_warning(int rc, char *seg_name)
716{
717	switch (rc) {
718	case -ENOENT:
719		pr_err("DCSS %s cannot be loaded or queried\n", seg_name);
720		break;
721	case -ENOSYS:
722		pr_err("DCSS %s cannot be loaded or queried without "
723		       "z/VM\n", seg_name);
724		break;
725	case -EIO:
726		pr_err("Loading or querying DCSS %s resulted in a "
727		       "hardware error\n", seg_name);
728		break;
729	case -EOPNOTSUPP:
730		pr_err("DCSS %s has multiple page ranges and cannot be "
731		       "loaded or queried\n", seg_name);
732		break;
733	case -ENOSPC:
734		pr_err("DCSS %s overlaps with used storage and cannot "
735		       "be loaded\n", seg_name);
736		break;
737	case -EBUSY:
738		pr_err("%s needs used memory resources and cannot be "
739		       "loaded or queried\n", seg_name);
740		break;
741	case -EPERM:
742		pr_err("DCSS %s is already loaded in a different access "
743		       "mode\n", seg_name);
744		break;
745	case -ENOMEM:
746		pr_err("There is not enough memory to load or query "
747		       "DCSS %s\n", seg_name);
748		break;
749	case -ERANGE:
750		pr_err("DCSS %s exceeds the kernel mapping range (%lu) "
751		       "and cannot be loaded\n", seg_name, VMEM_MAX_PHYS);
752		break;
753	default:
754		break;
755	}
756}
757
758EXPORT_SYMBOL(segment_load);
759EXPORT_SYMBOL(segment_unload);
760EXPORT_SYMBOL(segment_save);
761EXPORT_SYMBOL(segment_type);
762EXPORT_SYMBOL(segment_modify_shared);
763EXPORT_SYMBOL(segment_warning);