xref: /linux/arch/s390/mm/extmem.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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;
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 		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  */
148 static void
149 dcss_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  */
168 static struct dcss_segment *
169 segment_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  */
191 static inline int
192 dcss_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 
229 static inline int
230 dcss_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  */
240 static int
241 query_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_warning("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  */
351 int
352 segment_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  */
371 static int
372 segment_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  */
394 static 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_warning("Loading DCSS %s failed with rc=%ld\n", name,
461 			   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_warning("DCSS %s is in use and cannot be reloaded\n",
578 			   name);
579 		rc = -EAGAIN;
580 		goto out_unlock;
581 	}
582 	release_resource(seg->res);
583 	if (do_nonshared)
584 		seg->res->flags &= ~IORESOURCE_READONLY;
585 	else
586 		if (seg->vm_segtype == SEG_TYPE_SR ||
587 		    seg->vm_segtype == SEG_TYPE_ER)
588 			seg->res->flags |= IORESOURCE_READONLY;
589 
590 	if (request_resource(&iomem_resource, seg->res)) {
591 		pr_warning("DCSS %s overlaps with used memory resources "
592 			   "and cannot be reloaded\n", name);
593 		rc = -EBUSY;
594 		kfree(seg->res);
595 		goto out_del_mem;
596 	}
597 
598 	dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
599 	if (do_nonshared)
600 		diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
601 				&start_addr, &end_addr);
602 	else
603 		diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
604 				&start_addr, &end_addr);
605 	if (diag_cc < 0) {
606 		rc = diag_cc;
607 		goto out_del_res;
608 	}
609 	if (diag_cc > 1) {
610 		pr_warning("Reloading DCSS %s failed with rc=%ld\n", name,
611 			   end_addr);
612 		rc = dcss_diag_translate_rc(end_addr);
613 		goto out_del_res;
614 	}
615 	seg->start_addr = start_addr;
616 	seg->end = end_addr;
617 	seg->do_nonshared = do_nonshared;
618 	rc = 0;
619 	goto out_unlock;
620  out_del_res:
621 	release_resource(seg->res);
622 	kfree(seg->res);
623  out_del_mem:
624 	vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
625 	list_del(&seg->list);
626 	dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
627 	kfree(seg);
628  out_unlock:
629 	mutex_unlock(&dcss_lock);
630 	return rc;
631 }
632 
633 /*
634  * Decrease the use count of a DCSS segment and remove
635  * it from the address space if nobody is using it
636  * any longer.
637  */
638 void
639 segment_unload(char *name)
640 {
641 	unsigned long dummy;
642 	struct dcss_segment *seg;
643 
644 	if (!MACHINE_IS_VM)
645 		return;
646 
647 	mutex_lock(&dcss_lock);
648 	seg = segment_by_name (name);
649 	if (seg == NULL) {
650 		pr_err("Unloading unknown DCSS %s failed\n", name);
651 		goto out_unlock;
652 	}
653 	if (atomic_dec_return(&seg->ref_count) != 0)
654 		goto out_unlock;
655 	release_resource(seg->res);
656 	kfree(seg->res);
657 	vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
658 	list_del(&seg->list);
659 	dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
660 	kfree(seg);
661 out_unlock:
662 	mutex_unlock(&dcss_lock);
663 }
664 
665 /*
666  * save segment content permanently
667  */
668 void
669 segment_save(char *name)
670 {
671 	struct dcss_segment *seg;
672 	char cmd1[160];
673 	char cmd2[80];
674 	int i, response;
675 
676 	if (!MACHINE_IS_VM)
677 		return;
678 
679 	mutex_lock(&dcss_lock);
680 	seg = segment_by_name (name);
681 
682 	if (seg == NULL) {
683 		pr_err("Saving unknown DCSS %s failed\n", name);
684 		goto out;
685 	}
686 
687 	sprintf(cmd1, "DEFSEG %s", name);
688 	for (i=0; i<seg->segcnt; i++) {
689 		sprintf(cmd1+strlen(cmd1), " %lX-%lX %s",
690 			seg->range[i].start >> PAGE_SHIFT,
691 			seg->range[i].end >> PAGE_SHIFT,
692 			segtype_string[seg->range[i].start & 0xff]);
693 	}
694 	sprintf(cmd2, "SAVESEG %s", name);
695 	response = 0;
696 	cpcmd(cmd1, NULL, 0, &response);
697 	if (response) {
698 		pr_err("Saving a DCSS failed with DEFSEG response code "
699 		       "%i\n", response);
700 		goto out;
701 	}
702 	cpcmd(cmd2, NULL, 0, &response);
703 	if (response) {
704 		pr_err("Saving a DCSS failed with SAVESEG response code "
705 		       "%i\n", response);
706 		goto out;
707 	}
708 out:
709 	mutex_unlock(&dcss_lock);
710 }
711 
712 /*
713  * print appropriate error message for segment_load()/segment_type()
714  * return code
715  */
716 void segment_warning(int rc, char *seg_name)
717 {
718 	switch (rc) {
719 	case -ENOENT:
720 		pr_err("DCSS %s cannot be loaded or queried\n", seg_name);
721 		break;
722 	case -ENOSYS:
723 		pr_err("DCSS %s cannot be loaded or queried without "
724 		       "z/VM\n", seg_name);
725 		break;
726 	case -EIO:
727 		pr_err("Loading or querying DCSS %s resulted in a "
728 		       "hardware error\n", seg_name);
729 		break;
730 	case -EOPNOTSUPP:
731 		pr_err("DCSS %s has multiple page ranges and cannot be "
732 		       "loaded or queried\n", seg_name);
733 		break;
734 	case -ENOSPC:
735 		pr_err("DCSS %s overlaps with used storage and cannot "
736 		       "be loaded\n", seg_name);
737 		break;
738 	case -EBUSY:
739 		pr_err("%s needs used memory resources and cannot be "
740 		       "loaded or queried\n", seg_name);
741 		break;
742 	case -EPERM:
743 		pr_err("DCSS %s is already loaded in a different access "
744 		       "mode\n", seg_name);
745 		break;
746 	case -ENOMEM:
747 		pr_err("There is not enough memory to load or query "
748 		       "DCSS %s\n", seg_name);
749 		break;
750 	case -ERANGE:
751 		pr_err("DCSS %s exceeds the kernel mapping range (%lu) "
752 		       "and cannot be loaded\n", seg_name, VMEM_MAX_PHYS);
753 		break;
754 	default:
755 		break;
756 	}
757 }
758 
759 EXPORT_SYMBOL(segment_load);
760 EXPORT_SYMBOL(segment_unload);
761 EXPORT_SYMBOL(segment_save);
762 EXPORT_SYMBOL(segment_type);
763 EXPORT_SYMBOL(segment_modify_shared);
764 EXPORT_SYMBOL(segment_warning);
765