xref: /linux/arch/s390/mm/extmem.c (revision b24413180f5600bcb3bb70fbed5cf186b60864bd)
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 
43 struct qrange {
44 	unsigned long  start; /* last byte type */
45 	unsigned long  end;   /* last byte reserved */
46 };
47 
48 struct qout64 {
49 	unsigned long segstart;
50 	unsigned long segend;
51 	int segcnt;
52 	int segrcnt;
53 	struct qrange range[6];
54 };
55 
56 struct 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' */
62 struct qout64_old {
63 	int segstart;
64 	int segend;
65 	int segcnt;
66 	int segrcnt;
67 	struct qrange_old range[6];
68 };
69 
70 struct 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 
80 struct 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 
94 static DEFINE_MUTEX(dcss_lock);
95 static LIST_HEAD(dcss_list);
96 static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
97 					"EW/EN-MIXED" };
98 static int loadshr_scode, loadnsr_scode;
99 static int segext_scode, purgeseg_scode;
100 static int scode_set;
101 
102 /* set correct Diag x'64' subcodes. */
103 static int
104 dcss_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  */
149 static void
150 dcss_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  */
169 static struct dcss_segment *
170 segment_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  */
192 static inline int
193 dcss_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 
230 static inline int
231 dcss_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  */
241 static int
242 query_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  */
352 int
353 segment_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  */
372 static int
373 segment_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  */
395 static 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  */
514 int
515 segment_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  */
556 int
557 segment_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  */
637 void
638 segment_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);
660 out_unlock:
661 	mutex_unlock(&dcss_lock);
662 }
663 
664 /*
665  * save segment content permanently
666  */
667 void
668 segment_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 	}
707 out:
708 	mutex_unlock(&dcss_lock);
709 }
710 
711 /*
712  * print appropriate error message for segment_load()/segment_type()
713  * return code
714  */
715 void 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 
758 EXPORT_SYMBOL(segment_load);
759 EXPORT_SYMBOL(segment_unload);
760 EXPORT_SYMBOL(segment_save);
761 EXPORT_SYMBOL(segment_type);
762 EXPORT_SYMBOL(segment_modify_shared);
763 EXPORT_SYMBOL(segment_warning);
764