xref: /openbmc/linux/arch/s390/mm/extmem.c (revision 0f4630f3)
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 
42 struct qrange {
43 	unsigned long  start; /* last byte type */
44 	unsigned long  end;   /* last byte reserved */
45 };
46 
47 struct qout64 {
48 	unsigned long segstart;
49 	unsigned long segend;
50 	int segcnt;
51 	int segrcnt;
52 	struct qrange range[6];
53 };
54 
55 struct 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' */
61 struct qout64_old {
62 	int segstart;
63 	int segend;
64 	int segcnt;
65 	int segrcnt;
66 	struct qrange_old range[6];
67 };
68 
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;
77 };
78 
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;
91 };
92 
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, findseg_scode;
98 static int segext_scode, purgeseg_scode;
99 static int scode_set;
100 
101 /* set correct Diag x'64' subcodes. */
102 static int
103 dcss_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 		findseg_scode = DCSS_FINDSEGX;
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 	findseg_scode = DCSS_FINDSEG;
142 	segext_scode = DCSS_SEGEXT;
143 	return 0;
144 }
145 
146 /*
147  * Create the 8 bytes, ebcdic VM segment name from
148  * an ascii name.
149  */
150 static void
151 dcss_mkname(char *name, char *dcss_name)
152 {
153 	int i;
154 
155 	for (i = 0; i < 8; i++) {
156 		if (name[i] == '\0')
157 			break;
158 		dcss_name[i] = toupper(name[i]);
159 	};
160 	for (; i < 8; i++)
161 		dcss_name[i] = ' ';
162 	ASCEBC(dcss_name, 8);
163 }
164 
165 
166 /*
167  * search all segments in dcss_list, and return the one
168  * namend *name. If not found, return NULL.
169  */
170 static struct dcss_segment *
171 segment_by_name (char *name)
172 {
173 	char dcss_name[9];
174 	struct list_head *l;
175 	struct dcss_segment *tmp, *retval = NULL;
176 
177 	BUG_ON(!mutex_is_locked(&dcss_lock));
178 	dcss_mkname (name, dcss_name);
179 	list_for_each (l, &dcss_list) {
180 		tmp = list_entry (l, struct dcss_segment, list);
181 		if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
182 			retval = tmp;
183 			break;
184 		}
185 	}
186 	return retval;
187 }
188 
189 
190 /*
191  * Perform a function on a dcss segment.
192  */
193 static inline int
194 dcss_diag(int *func, void *parameter,
195            unsigned long *ret1, unsigned long *ret2)
196 {
197 	unsigned long rx, ry;
198 	int rc;
199 
200 	if (scode_set == 0) {
201 		rc = dcss_set_subcodes();
202 		if (rc < 0)
203 			return rc;
204 		scode_set = 1;
205 	}
206 	rx = (unsigned long) parameter;
207 	ry = (unsigned long) *func;
208 
209 	/* 64-bit Diag x'64' new subcode, keep in 64-bit addressing mode */
210 	diag_stat_inc(DIAG_STAT_X064);
211 	if (*func > DCSS_SEGEXT)
212 		asm volatile(
213 			"	diag	%0,%1,0x64\n"
214 			"	ipm	%2\n"
215 			"	srl	%2,28\n"
216 			: "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
217 	/* 31-bit Diag x'64' old subcode, switch to 31-bit addressing mode */
218 	else
219 		asm volatile(
220 			"	sam31\n"
221 			"	diag	%0,%1,0x64\n"
222 			"	sam64\n"
223 			"	ipm	%2\n"
224 			"	srl	%2,28\n"
225 			: "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
226 	*ret1 = rx;
227 	*ret2 = ry;
228 	return rc;
229 }
230 
231 static inline int
232 dcss_diag_translate_rc (int vm_rc) {
233 	if (vm_rc == 44)
234 		return -ENOENT;
235 	return -EIO;
236 }
237 
238 
239 /* do a diag to get info about a segment.
240  * fills start_address, end and vm_segtype fields
241  */
242 static int
243 query_segment_type (struct dcss_segment *seg)
244 {
245 	unsigned long dummy, vmrc;
246 	int diag_cc, rc, i;
247 	struct qout64 *qout;
248 	struct qin64 *qin;
249 
250 	qin = kmalloc(sizeof(*qin), GFP_KERNEL | GFP_DMA);
251 	qout = kmalloc(sizeof(*qout), GFP_KERNEL | GFP_DMA);
252 	if ((qin == NULL) || (qout == NULL)) {
253 		rc = -ENOMEM;
254 		goto out_free;
255 	}
256 
257 	/* initialize diag input parameters */
258 	qin->qopcode = DCSS_FINDSEGA;
259 	qin->qoutptr = (unsigned long) qout;
260 	qin->qoutlen = sizeof(struct qout64);
261 	memcpy (qin->qname, seg->dcss_name, 8);
262 
263 	diag_cc = dcss_diag(&segext_scode, qin, &dummy, &vmrc);
264 
265 	if (diag_cc < 0) {
266 		rc = diag_cc;
267 		goto out_free;
268 	}
269 	if (diag_cc > 1) {
270 		pr_warning("Querying a DCSS type failed with rc=%ld\n", vmrc);
271 		rc = dcss_diag_translate_rc (vmrc);
272 		goto out_free;
273 	}
274 
275 	/* Only old format of output area of Diagnose x'64' is supported,
276 	   copy data for the new format. */
277 	if (segext_scode == DCSS_SEGEXT) {
278 		struct qout64_old *qout_old;
279 		qout_old = kzalloc(sizeof(*qout_old), GFP_KERNEL | GFP_DMA);
280 		if (qout_old == NULL) {
281 			rc = -ENOMEM;
282 			goto out_free;
283 		}
284 		memcpy(qout_old, qout, sizeof(struct qout64_old));
285 		qout->segstart = (unsigned long) qout_old->segstart;
286 		qout->segend = (unsigned long) qout_old->segend;
287 		qout->segcnt = qout_old->segcnt;
288 		qout->segrcnt = qout_old->segrcnt;
289 
290 		if (qout->segcnt > 6)
291 			qout->segrcnt = 6;
292 		for (i = 0; i < qout->segrcnt; i++) {
293 			qout->range[i].start =
294 				(unsigned long) qout_old->range[i].start;
295 			qout->range[i].end =
296 				(unsigned long) qout_old->range[i].end;
297 		}
298 		kfree(qout_old);
299 	}
300 	if (qout->segcnt > 6) {
301 		rc = -EOPNOTSUPP;
302 		goto out_free;
303 	}
304 
305 	if (qout->segcnt == 1) {
306 		seg->vm_segtype = qout->range[0].start & 0xff;
307 	} else {
308 		/* multi-part segment. only one type supported here:
309 		    - all parts are contiguous
310 		    - all parts are either EW or EN type
311 		    - maximum 6 parts allowed */
312 		unsigned long start = qout->segstart >> PAGE_SHIFT;
313 		for (i=0; i<qout->segcnt; i++) {
314 			if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
315 			    ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
316 				rc = -EOPNOTSUPP;
317 				goto out_free;
318 			}
319 			if (start != qout->range[i].start >> PAGE_SHIFT) {
320 				rc = -EOPNOTSUPP;
321 				goto out_free;
322 			}
323 			start = (qout->range[i].end >> PAGE_SHIFT) + 1;
324 		}
325 		seg->vm_segtype = SEG_TYPE_EWEN;
326 	}
327 
328 	/* analyze diag output and update seg */
329 	seg->start_addr = qout->segstart;
330 	seg->end = qout->segend;
331 
332 	memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
333 	seg->segcnt = qout->segcnt;
334 
335 	rc = 0;
336 
337  out_free:
338 	kfree(qin);
339 	kfree(qout);
340 	return rc;
341 }
342 
343 /*
344  * get info about a segment
345  * possible return values:
346  * -ENOSYS  : we are not running on VM
347  * -EIO     : could not perform query diagnose
348  * -ENOENT  : no such segment
349  * -EOPNOTSUPP: multi-part segment cannot be used with linux
350  * -ENOMEM  : out of memory
351  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
352  */
353 int
354 segment_type (char* name)
355 {
356 	int rc;
357 	struct dcss_segment seg;
358 
359 	if (!MACHINE_IS_VM)
360 		return -ENOSYS;
361 
362 	dcss_mkname(name, seg.dcss_name);
363 	rc = query_segment_type (&seg);
364 	if (rc < 0)
365 		return rc;
366 	return seg.vm_segtype;
367 }
368 
369 /*
370  * check if segment collides with other segments that are currently loaded
371  * returns 1 if this is the case, 0 if no collision was found
372  */
373 static int
374 segment_overlaps_others (struct dcss_segment *seg)
375 {
376 	struct list_head *l;
377 	struct dcss_segment *tmp;
378 
379 	BUG_ON(!mutex_is_locked(&dcss_lock));
380 	list_for_each(l, &dcss_list) {
381 		tmp = list_entry(l, struct dcss_segment, list);
382 		if ((tmp->start_addr >> 20) > (seg->end >> 20))
383 			continue;
384 		if ((tmp->end >> 20) < (seg->start_addr >> 20))
385 			continue;
386 		if (seg == tmp)
387 			continue;
388 		return 1;
389 	}
390 	return 0;
391 }
392 
393 /*
394  * real segment loading function, called from segment_load
395  */
396 static int
397 __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
398 {
399 	unsigned long start_addr, end_addr, dummy;
400 	struct dcss_segment *seg;
401 	int rc, diag_cc;
402 
403 	start_addr = end_addr = 0;
404 	seg = kmalloc(sizeof(*seg), GFP_KERNEL | GFP_DMA);
405 	if (seg == NULL) {
406 		rc = -ENOMEM;
407 		goto out;
408 	}
409 	dcss_mkname (name, seg->dcss_name);
410 	rc = query_segment_type (seg);
411 	if (rc < 0)
412 		goto out_free;
413 
414 	if (loadshr_scode == DCSS_LOADSHRX) {
415 		if (segment_overlaps_others(seg)) {
416 			rc = -EBUSY;
417 			goto out_free;
418 		}
419 	}
420 
421 	rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
422 
423 	if (rc)
424 		goto out_free;
425 
426 	seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
427 	if (seg->res == NULL) {
428 		rc = -ENOMEM;
429 		goto out_shared;
430 	}
431 	seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
432 	seg->res->start = seg->start_addr;
433 	seg->res->end = seg->end;
434 	memcpy(&seg->res_name, seg->dcss_name, 8);
435 	EBCASC(seg->res_name, 8);
436 	seg->res_name[8] = '\0';
437 	strncat(seg->res_name, " (DCSS)", 7);
438 	seg->res->name = seg->res_name;
439 	rc = seg->vm_segtype;
440 	if (rc == SEG_TYPE_SC ||
441 	    ((rc == SEG_TYPE_SR || rc == SEG_TYPE_ER) && !do_nonshared))
442 		seg->res->flags |= IORESOURCE_READONLY;
443 	if (request_resource(&iomem_resource, seg->res)) {
444 		rc = -EBUSY;
445 		kfree(seg->res);
446 		goto out_shared;
447 	}
448 
449 	if (do_nonshared)
450 		diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
451 				&start_addr, &end_addr);
452 	else
453 		diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
454 				&start_addr, &end_addr);
455 	if (diag_cc < 0) {
456 		dcss_diag(&purgeseg_scode, seg->dcss_name,
457 				&dummy, &dummy);
458 		rc = diag_cc;
459 		goto out_resource;
460 	}
461 	if (diag_cc > 1) {
462 		pr_warning("Loading DCSS %s failed with rc=%ld\n", name,
463 			   end_addr);
464 		rc = dcss_diag_translate_rc(end_addr);
465 		dcss_diag(&purgeseg_scode, seg->dcss_name,
466 				&dummy, &dummy);
467 		goto out_resource;
468 	}
469 	seg->start_addr = start_addr;
470 	seg->end = end_addr;
471 	seg->do_nonshared = do_nonshared;
472 	atomic_set(&seg->ref_count, 1);
473 	list_add(&seg->list, &dcss_list);
474 	*addr = seg->start_addr;
475 	*end  = seg->end;
476 	if (do_nonshared)
477 		pr_info("DCSS %s of range %p to %p and type %s loaded as "
478 			"exclusive-writable\n", name, (void*) seg->start_addr,
479 			(void*) seg->end, segtype_string[seg->vm_segtype]);
480 	else {
481 		pr_info("DCSS %s of range %p to %p and type %s loaded in "
482 			"shared access mode\n", name, (void*) seg->start_addr,
483 			(void*) seg->end, segtype_string[seg->vm_segtype]);
484 	}
485 	goto out;
486  out_resource:
487 	release_resource(seg->res);
488 	kfree(seg->res);
489  out_shared:
490 	vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
491  out_free:
492 	kfree(seg);
493  out:
494 	return rc;
495 }
496 
497 /*
498  * this function loads a DCSS segment
499  * name         : name of the DCSS
500  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
501  *                1 indicates that the dcss should be exclusive for this linux image
502  * addr         : will be filled with start address of the segment
503  * end          : will be filled with end address of the segment
504  * return values:
505  * -ENOSYS  : we are not running on VM
506  * -EIO     : could not perform query or load diagnose
507  * -ENOENT  : no such segment
508  * -EOPNOTSUPP: multi-part segment cannot be used with linux
509  * -ENOSPC  : segment cannot be used (overlaps with storage)
510  * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
511  * -ERANGE  : segment cannot be used (exceeds kernel mapping range)
512  * -EPERM   : segment is currently loaded with incompatible permissions
513  * -ENOMEM  : out of memory
514  * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
515  */
516 int
517 segment_load (char *name, int do_nonshared, unsigned long *addr,
518 		unsigned long *end)
519 {
520 	struct dcss_segment *seg;
521 	int rc;
522 
523 	if (!MACHINE_IS_VM)
524 		return -ENOSYS;
525 
526 	mutex_lock(&dcss_lock);
527 	seg = segment_by_name (name);
528 	if (seg == NULL)
529 		rc = __segment_load (name, do_nonshared, addr, end);
530 	else {
531 		if (do_nonshared == seg->do_nonshared) {
532 			atomic_inc(&seg->ref_count);
533 			*addr = seg->start_addr;
534 			*end  = seg->end;
535 			rc    = seg->vm_segtype;
536 		} else {
537 			*addr = *end = 0;
538 			rc    = -EPERM;
539 		}
540 	}
541 	mutex_unlock(&dcss_lock);
542 	return rc;
543 }
544 
545 /*
546  * this function modifies the shared state of a DCSS segment. note that
547  * name         : name of the DCSS
548  * do_nonshared : 0 indicates that the dcss should be shared with other linux images
549  *                1 indicates that the dcss should be exclusive for this linux image
550  * return values:
551  * -EIO     : could not perform load diagnose (segment gone!)
552  * -ENOENT  : no such segment (segment gone!)
553  * -EAGAIN  : segment is in use by other exploiters, try later
554  * -EINVAL  : no segment with the given name is currently loaded - name invalid
555  * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
556  * 0	    : operation succeeded
557  */
558 int
559 segment_modify_shared (char *name, int do_nonshared)
560 {
561 	struct dcss_segment *seg;
562 	unsigned long start_addr, end_addr, dummy;
563 	int rc, diag_cc;
564 
565 	start_addr = end_addr = 0;
566 	mutex_lock(&dcss_lock);
567 	seg = segment_by_name (name);
568 	if (seg == NULL) {
569 		rc = -EINVAL;
570 		goto out_unlock;
571 	}
572 	if (do_nonshared == seg->do_nonshared) {
573 		pr_info("DCSS %s is already in the requested access "
574 			"mode\n", name);
575 		rc = 0;
576 		goto out_unlock;
577 	}
578 	if (atomic_read (&seg->ref_count) != 1) {
579 		pr_warning("DCSS %s is in use and cannot be reloaded\n",
580 			   name);
581 		rc = -EAGAIN;
582 		goto out_unlock;
583 	}
584 	release_resource(seg->res);
585 	if (do_nonshared)
586 		seg->res->flags &= ~IORESOURCE_READONLY;
587 	else
588 		if (seg->vm_segtype == SEG_TYPE_SR ||
589 		    seg->vm_segtype == SEG_TYPE_ER)
590 			seg->res->flags |= IORESOURCE_READONLY;
591 
592 	if (request_resource(&iomem_resource, seg->res)) {
593 		pr_warning("DCSS %s overlaps with used memory resources "
594 			   "and cannot be reloaded\n", name);
595 		rc = -EBUSY;
596 		kfree(seg->res);
597 		goto out_del_mem;
598 	}
599 
600 	dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
601 	if (do_nonshared)
602 		diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
603 				&start_addr, &end_addr);
604 	else
605 		diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
606 				&start_addr, &end_addr);
607 	if (diag_cc < 0) {
608 		rc = diag_cc;
609 		goto out_del_res;
610 	}
611 	if (diag_cc > 1) {
612 		pr_warning("Reloading DCSS %s failed with rc=%ld\n", name,
613 			   end_addr);
614 		rc = dcss_diag_translate_rc(end_addr);
615 		goto out_del_res;
616 	}
617 	seg->start_addr = start_addr;
618 	seg->end = end_addr;
619 	seg->do_nonshared = do_nonshared;
620 	rc = 0;
621 	goto out_unlock;
622  out_del_res:
623 	release_resource(seg->res);
624 	kfree(seg->res);
625  out_del_mem:
626 	vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
627 	list_del(&seg->list);
628 	dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
629 	kfree(seg);
630  out_unlock:
631 	mutex_unlock(&dcss_lock);
632 	return rc;
633 }
634 
635 /*
636  * Decrease the use count of a DCSS segment and remove
637  * it from the address space if nobody is using it
638  * any longer.
639  */
640 void
641 segment_unload(char *name)
642 {
643 	unsigned long dummy;
644 	struct dcss_segment *seg;
645 
646 	if (!MACHINE_IS_VM)
647 		return;
648 
649 	mutex_lock(&dcss_lock);
650 	seg = segment_by_name (name);
651 	if (seg == NULL) {
652 		pr_err("Unloading unknown DCSS %s failed\n", name);
653 		goto out_unlock;
654 	}
655 	if (atomic_dec_return(&seg->ref_count) != 0)
656 		goto out_unlock;
657 	release_resource(seg->res);
658 	kfree(seg->res);
659 	vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
660 	list_del(&seg->list);
661 	dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
662 	kfree(seg);
663 out_unlock:
664 	mutex_unlock(&dcss_lock);
665 }
666 
667 /*
668  * save segment content permanently
669  */
670 void
671 segment_save(char *name)
672 {
673 	struct dcss_segment *seg;
674 	char cmd1[160];
675 	char cmd2[80];
676 	int i, response;
677 
678 	if (!MACHINE_IS_VM)
679 		return;
680 
681 	mutex_lock(&dcss_lock);
682 	seg = segment_by_name (name);
683 
684 	if (seg == NULL) {
685 		pr_err("Saving unknown DCSS %s failed\n", name);
686 		goto out;
687 	}
688 
689 	sprintf(cmd1, "DEFSEG %s", name);
690 	for (i=0; i<seg->segcnt; i++) {
691 		sprintf(cmd1+strlen(cmd1), " %lX-%lX %s",
692 			seg->range[i].start >> PAGE_SHIFT,
693 			seg->range[i].end >> PAGE_SHIFT,
694 			segtype_string[seg->range[i].start & 0xff]);
695 	}
696 	sprintf(cmd2, "SAVESEG %s", name);
697 	response = 0;
698 	cpcmd(cmd1, NULL, 0, &response);
699 	if (response) {
700 		pr_err("Saving a DCSS failed with DEFSEG response code "
701 		       "%i\n", response);
702 		goto out;
703 	}
704 	cpcmd(cmd2, NULL, 0, &response);
705 	if (response) {
706 		pr_err("Saving a DCSS failed with SAVESEG response code "
707 		       "%i\n", response);
708 		goto out;
709 	}
710 out:
711 	mutex_unlock(&dcss_lock);
712 }
713 
714 /*
715  * print appropriate error message for segment_load()/segment_type()
716  * return code
717  */
718 void segment_warning(int rc, char *seg_name)
719 {
720 	switch (rc) {
721 	case -ENOENT:
722 		pr_err("DCSS %s cannot be loaded or queried\n", seg_name);
723 		break;
724 	case -ENOSYS:
725 		pr_err("DCSS %s cannot be loaded or queried without "
726 		       "z/VM\n", seg_name);
727 		break;
728 	case -EIO:
729 		pr_err("Loading or querying DCSS %s resulted in a "
730 		       "hardware error\n", seg_name);
731 		break;
732 	case -EOPNOTSUPP:
733 		pr_err("DCSS %s has multiple page ranges and cannot be "
734 		       "loaded or queried\n", seg_name);
735 		break;
736 	case -ENOSPC:
737 		pr_err("DCSS %s overlaps with used storage and cannot "
738 		       "be loaded\n", seg_name);
739 		break;
740 	case -EBUSY:
741 		pr_err("%s needs used memory resources and cannot be "
742 		       "loaded or queried\n", seg_name);
743 		break;
744 	case -EPERM:
745 		pr_err("DCSS %s is already loaded in a different access "
746 		       "mode\n", seg_name);
747 		break;
748 	case -ENOMEM:
749 		pr_err("There is not enough memory to load or query "
750 		       "DCSS %s\n", seg_name);
751 		break;
752 	case -ERANGE:
753 		pr_err("DCSS %s exceeds the kernel mapping range (%lu) "
754 		       "and cannot be loaded\n", seg_name, VMEM_MAX_PHYS);
755 		break;
756 	default:
757 		break;
758 	}
759 }
760 
761 EXPORT_SYMBOL(segment_load);
762 EXPORT_SYMBOL(segment_unload);
763 EXPORT_SYMBOL(segment_save);
764 EXPORT_SYMBOL(segment_type);
765 EXPORT_SYMBOL(segment_modify_shared);
766 EXPORT_SYMBOL(segment_warning);
767