aboutsummaryrefslogtreecommitdiffstats
path: root/arch/s390/mm/extmem.c
blob: 8bffadb5e537b7e9e3cdd3208db26d37b6830dd0 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
/*
 * File...........: arch/s390/mm/extmem.c
 * Author(s)......: Carsten Otte <cotte@de.ibm.com>
 * 		    Rob M van der Heij <rvdheij@nl.ibm.com>
 * 		    Steven Shultz <shultzss@us.ibm.com>
 * Bugreports.to..: <Linux390@de.ibm.com>
 * (C) IBM Corporation 2002-2004
 */

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/bootmem.h>
#include <linux/ctype.h>
#include <linux/ioport.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/ebcdic.h>
#include <asm/errno.h>
#include <asm/extmem.h>
#include <asm/cpcmd.h>
#include <asm/setup.h>

#define DCSS_DEBUG	/* Debug messages on/off */

#define DCSS_NAME "extmem"
#ifdef DCSS_DEBUG
#define PRINT_DEBUG(x...)	printk(KERN_DEBUG DCSS_NAME " debug:" x)
#else
#define PRINT_DEBUG(x...)   do {} while (0)
#endif
#define PRINT_INFO(x...)	printk(KERN_INFO DCSS_NAME " info:" x)
#define PRINT_WARN(x...)	printk(KERN_WARNING DCSS_NAME " warning:" x)
#define PRINT_ERR(x...)		printk(KERN_ERR DCSS_NAME " error:" x)


#define DCSS_LOADSHR    0x00
#define DCSS_LOADNSR    0x04
#define DCSS_PURGESEG   0x08
#define DCSS_FINDSEG    0x0c
#define DCSS_LOADNOLY   0x10
#define DCSS_SEGEXT     0x18
#define DCSS_FINDSEGA   0x0c

struct qrange {
	unsigned int  start; // 3byte start address, 1 byte type
	unsigned int  end;   // 3byte end address, 1 byte reserved
};

struct qout64 {
	int segstart;
	int segend;
	int segcnt;
	int segrcnt;
	struct qrange range[6];
};

struct qin64 {
	char qopcode;
	char rsrv1[3];
	char qrcode;
	char rsrv2[3];
	char qname[8];
	unsigned int qoutptr;
	short int qoutlen;
};

struct dcss_segment {
	struct list_head list;
	char dcss_name[8];
	char res_name[15];
	unsigned long start_addr;
	unsigned long end;
	atomic_t ref_count;
	int do_nonshared;
	unsigned int vm_segtype;
	struct qrange range[6];
	int segcnt;
	struct resource *res;
};

static DEFINE_MUTEX(dcss_lock);
static struct list_head dcss_list = LIST_HEAD_INIT(dcss_list);
static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
					"EW/EN-MIXED" };

/*
 * Create the 8 bytes, ebcdic VM segment name from
 * an ascii name.
 */
static void inline
dcss_mkname(char *name, char *dcss_name)
{
	int i;

	for (i = 0; i < 8; i++) {
		if (name[i] == '\0')
			break;
		dcss_name[i] = toupper(name[i]);
	};
	for (; i < 8; i++)
		dcss_name[i] = ' ';
	ASCEBC(dcss_name, 8);
}


/*
 * search all segments in dcss_list, and return the one
 * namend *name. If not found, return NULL.
 */
static struct dcss_segment *
segment_by_name (char *name)
{
	char dcss_name[9];
	struct list_head *l;
	struct dcss_segment *tmp, *retval = NULL;

	BUG_ON(!mutex_is_locked(&dcss_lock));
	dcss_mkname (name, dcss_name);
	list_for_each (l, &dcss_list) {
		tmp = list_entry (l, struct dcss_segment, list);
		if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
			retval = tmp;
			break;
		}
	}
	return retval;
}


/*
 * Perform a function on a dcss segment.
 */
static inline int
dcss_diag (__u8 func, void *parameter,
           unsigned long *ret1, unsigned long *ret2)
{
	unsigned long rx, ry;
	int rc;

	rx = (unsigned long) parameter;
	ry = (unsigned long) func;
	asm volatile(
#ifdef CONFIG_64BIT
		"	sam31\n"
		"	diag	%0,%1,0x64\n"
		"	sam64\n"
#else
		"	diag	%0,%1,0x64\n"
#endif
		"	ipm	%2\n"
		"	srl	%2,28\n"
		: "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
	*ret1 = rx;
	*ret2 = ry;
	return rc;
}

static inline int
dcss_diag_translate_rc (int vm_rc) {
	if (vm_rc == 44)
		return -ENOENT;
	return -EIO;
}


/* do a diag to get info about a segment.
 * fills start_address, end and vm_segtype fields
 */
static int
query_segment_type (struct dcss_segment *seg)
{
	struct qin64  *qin = kmalloc (sizeof(struct qin64), GFP_DMA);
	struct qout64 *qout = kmalloc (sizeof(struct qout64), GFP_DMA);

	int diag_cc, rc, i;
	unsigned long dummy, vmrc;

	if ((qin == NULL) || (qout == NULL)) {
		rc = -ENOMEM;
		goto out_free;
	}

	/* initialize diag input parameters */
	qin->qopcode = DCSS_FINDSEGA;
	qin->qoutptr = (unsigned long) qout;
	qin->qoutlen = sizeof(struct qout64);
	memcpy (qin->qname, seg->dcss_name, 8);

	diag_cc = dcss_diag (DCSS_SEGEXT, qin, &dummy, &vmrc);

	if (diag_cc > 1) {
		PRINT_WARN ("segment_type: diag returned error %ld\n", vmrc);
		rc = dcss_diag_translate_rc (vmrc);
		goto out_free;
	}

	if (qout->segcnt > 6) {
		rc = -ENOTSUPP;
		goto out_free;
	}

	if (qout->segcnt == 1) {
		seg->vm_segtype = qout->range[0].start & 0xff;
	} else {
		/* multi-part segment. only one type supported here:
		    - all parts are contiguous
		    - all parts are either EW or EN type
		    - maximum 6 parts allowed */
		unsigned long start = qout->segstart >> PAGE_SHIFT;
		for (i=0; i<qout->segcnt; i++) {
			if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) &&
			    ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) {
				rc = -ENOTSUPP;
				goto out_free;
			}
			if (start != qout->range[i].start >> PAGE_SHIFT) {
				rc = -ENOTSUPP;
				goto out_free;
			}
			start = (qout->range[i].end >> PAGE_SHIFT) + 1;
		}
		seg->vm_segtype = SEG_TYPE_EWEN;
	}

	/* analyze diag output and update seg */
	seg->start_addr = qout->segstart;
	seg->end = qout->segend;

	memcpy (seg->range, qout->range, 6*sizeof(struct qrange));
	seg->segcnt = qout->segcnt;

	rc = 0;

 out_free:
	kfree(qin);
	kfree(qout);
	return rc;
}

/*
 * get info about a segment
 * possible return values:
 * -ENOSYS  : we are not running on VM
 * -EIO     : could not perform query diagnose
 * -ENOENT  : no such segment
 * -ENOTSUPP: multi-part segment cannot be used with linux
 * -ENOSPC  : segment cannot be used (overlaps with storage)
 * -ENOMEM  : out of memory
 * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 */
int
segment_type (char* name)
{
	int rc;
	struct dcss_segment seg;

	if (!MACHINE_IS_VM)
		return -ENOSYS;

	dcss_mkname(name, seg.dcss_name);
	rc = query_segment_type (&seg);
	if (rc < 0)
		return rc;
	return seg.vm_segtype;
}

/*
 * real segment loading function, called from segment_load
 */
static int
__segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)
{
	struct dcss_segment *seg = kmalloc(sizeof(struct dcss_segment),
			GFP_DMA);
	int dcss_command, rc, diag_cc;

	if (seg == NULL) {
		rc = -ENOMEM;
		goto out;
	}
	dcss_mkname (name, seg->dcss_name);
	rc = query_segment_type (seg);
	if (rc < 0)
		goto out_free;

	rc = add_shared_memory(seg->start_addr, seg->end - seg->start_addr + 1);

	switch (rc) {
	case 0:
		break;
	case -ENOSPC:
		PRINT_WARN("segment_load: not loading segment %s - overlaps "
			   "storage/segment\n", name);
		goto out_free;
	case -ERANGE:
		PRINT_WARN("segment_load: not loading segment %s - exceeds "
			   "kernel mapping range\n", name);
		goto out_free;
	default:
		PRINT_WARN("segment_load: not loading segment %s (rc: %d)\n",
			   name, rc);
		goto out_free;
	}

	seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL);
	if (seg->res == NULL) {
		rc = -ENOMEM;
		goto out_shared;
	}
	seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
	seg->res->start = seg->start_addr;
	seg->res->end = seg->end;
	memcpy(&seg->res_name, seg->dcss_name, 8);
	EBCASC(seg->res_name, 8);
	seg->res_name[8] = '\0';
	strncat(seg->res_name, " (DCSS)", 7);
	seg->res->name = seg->res_name;
	rc = seg->vm_segtype;
	if (rc == SEG_TYPE_SC ||
	    ((rc == SEG_TYPE_SR || rc == SEG_TYPE_ER) && !do_nonshared))
		seg->res->flags |= IORESOURCE_READONLY;
	if (request_resource(&iomem_resource, seg->res)) {
		rc = -EBUSY;
		kfree(seg->res);
		goto out_shared;
	}

	if (do_nonshared)
		dcss_command = DCSS_LOADNSR;
	else
		dcss_command = DCSS_LOADNOLY;

	diag_cc = dcss_diag(dcss_command, seg->dcss_name,
			&seg->start_addr, &seg->end);
	if (diag_cc > 1) {
		PRINT_WARN ("segment_load: could not load segment %s - "
				"diag returned error (%ld)\n",name,seg->end);
		rc = dcss_diag_translate_rc (seg->end);
		dcss_diag(DCSS_PURGESEG, seg->dcss_name,
				&seg->start_addr, &seg->end);
		goto out_resource;
	}
	seg->do_nonshared = do_nonshared;
	atomic_set(&seg->ref_count, 1);
	list_add(&seg->list, &dcss_list);
	*addr = seg->start_addr;
	*end  = seg->end;
	if (do_nonshared)
		PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
				"type %s in non-shared mode\n", name,
				(void*)seg->start_addr, (void*)seg->end,
				segtype_string[seg->vm_segtype]);
	else {
		PRINT_INFO ("segment_load: loaded segment %s range %p .. %p "
				"type %s in shared mode\n", name,
				(void*)seg->start_addr, (void*)seg->end,
				segtype_string[seg->vm_segtype]);
	}
	goto out;
 out_resource:
	release_resource(seg->res);
	kfree(seg->res);
 out_shared:
	remove_shared_memory(seg->start_addr, seg->end - seg->start_addr + 1);
 out_free:
	kfree(seg);
 out:
	return rc;
}

/*
 * this function loads a DCSS segment
 * name         : name of the DCSS
 * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 *                1 indicates that the dcss should be exclusive for this linux image
 * addr         : will be filled with start address of the segment
 * end          : will be filled with end address of the segment
 * return values:
 * -ENOSYS  : we are not running on VM
 * -EIO     : could not perform query or load diagnose
 * -ENOENT  : no such segment
 * -ENOTSUPP: multi-part segment cannot be used with linux
 * -ENOSPC  : segment cannot be used (overlaps with storage)
 * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
 * -ERANGE  : segment cannot be used (exceeds kernel mapping range)
 * -EPERM   : segment is currently loaded with incompatible permissions
 * -ENOMEM  : out of memory
 * 0 .. 6   : type of segment as defined in include/asm-s390/extmem.h
 */
int
segment_load (char *name, int do_nonshared, unsigned long *addr,
		unsigned long *end)
{
	struct dcss_segment *seg;
	int rc;

	if (!MACHINE_IS_VM)
		return -ENOSYS;

	mutex_lock(&dcss_lock);
	seg = segment_by_name (name);
	if (seg == NULL)
		rc = __segment_load (name, do_nonshared, addr, end);
	else {
		if (do_nonshared == seg->do_nonshared) {
			atomic_inc(&seg->ref_count);
			*addr = seg->start_addr;
			*end  = seg->end;
			rc    = seg->vm_segtype;
		} else {
			*addr = *end = 0;
			rc    = -EPERM;
		}
	}
	mutex_unlock(&dcss_lock);
	return rc;
}

/*
 * this function modifies the shared state of a DCSS segment. note that
 * name         : name of the DCSS
 * do_nonshared : 0 indicates that the dcss should be shared with other linux images
 *                1 indicates that the dcss should be exclusive for this linux image
 * return values:
 * -EIO     : could not perform load diagnose (segment gone!)
 * -ENOENT  : no such segment (segment gone!)
 * -EAGAIN  : segment is in use by other exploiters, try later
 * -EINVAL  : no segment with the given name is currently loaded - name invalid
 * -EBUSY   : segment can temporarily not be used (overlaps with dcss)
 * 0	    : operation succeeded
 */
int
segment_modify_shared (char *name, int do_nonshared)
{
	struct dcss_segment *seg;
	unsigned long dummy;
	int dcss_command, rc, diag_cc;

	mutex_lock(&dcss_lock);
	seg = segment_by_name (name);
	if (seg == NULL) {
		rc = -EINVAL;
		goto out_unlock;
	}
	if (do_nonshared == seg->do_nonshared) {
		PRINT_INFO ("segment_modify_shared: not reloading segment %s"
				" - already in requested mode\n",name);
		rc = 0;
		goto out_unlock;
	}
	if (atomic_read (&seg->ref_count) != 1) {
		PRINT_WARN ("segment_modify_shared: not reloading segment %s - "
				"segment is in use by other driver(s)\n",name);
		rc = -EAGAIN;
		goto out_unlock;
	}
	release_resource(seg->res);
	if (do_nonshared) {
		dcss_command = DCSS_LOADNSR;
		seg->res->flags &= ~IORESOURCE_READONLY;
	} else {
		dcss_command = DCSS_LOADNOLY;
		if (seg->vm_segtype == SEG_TYPE_SR ||
		    seg->vm_segtype == SEG_TYPE_ER)
			seg->res->flags |= IORESOURCE_READONLY;
	}
	if (request_resource(&iomem_resource, seg->res)) {
		PRINT_WARN("segment_modify_shared: could not reload segment %s"
			   " - overlapping resources\n", name);
		rc = -EBUSY;
		kfree(seg->res);
		goto out_del;
	}
	dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
	diag_cc = dcss_diag(dcss_command, seg->dcss_name,
			&seg->start_addr, &seg->end);
	if (diag_cc > 1) {
		PRINT_WARN ("segment_modify_shared: could not reload segment %s"
				" - diag returned error (%ld)\n",name,seg->end);
		rc = dcss_diag_translate_rc (seg->end);
		goto out_del;
	}
	seg->do_nonshared = do_nonshared;
	rc = 0;
	goto out_unlock;
 out_del:
	remove_shared_memory(seg->start_addr, seg->end - seg->start_addr + 1);
	list_del(&seg->list);
	dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
	kfree(seg);
 out_unlock:
	mutex_unlock(&dcss_lock);
	return rc;
}

/*
 * Decrease the use count of a DCSS segment and remove
 * it from the address space if nobody is using it
 * any longer.
 */
void
segment_unload(char *name)
{
	unsigned long dummy;
	struct dcss_segment *seg;

	if (!MACHINE_IS_VM)
		return;

	mutex_lock(&dcss_lock);
	seg = segment_by_name (name);
	if (seg == NULL) {
		PRINT_ERR ("could not find segment %s in segment_unload, "
				"please report to linux390@de.ibm.com\n",name);
		goto out_unlock;
	}
	if (atomic_dec_return(&seg->ref_count) != 0)
		goto out_unlock;
	release_resource(seg->res);
	kfree(seg->res);
	remove_shared_memory(seg->start_addr, seg->end - seg->start_addr + 1);
	list_del(&seg->list);
	dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
	kfree(seg);
out_unlock:
	mutex_unlock(&dcss_lock);
}

/*
 * save segment content permanently
 */
void
segment_save(char *name)
{
	struct dcss_segment *seg;
	int startpfn = 0;
	int endpfn = 0;
	char cmd1[160];
	char cmd2[80];
	int i, response;

	if (!MACHINE_IS_VM)
		return;

	mutex_lock(&dcss_lock);
	seg = segment_by_name (name);

	if (seg == NULL) {
		PRINT_ERR("could not find segment %s in segment_save, please "
			  "report to linux390@de.ibm.com\n", name);
		goto out;
	}

	startpfn = seg->start_addr >> PAGE_SHIFT;
	endpfn = (seg->end) >> PAGE_SHIFT;
	sprintf(cmd1, "DEFSEG %s", name);
	for (i=0; i<seg->segcnt; i++) {
		sprintf(cmd1+strlen(cmd1), " %X-%X %s",
			seg->range[i].start >> PAGE_SHIFT,
			seg->range[i].end >> PAGE_SHIFT,
			segtype_string[seg->range[i].start & 0xff]);
	}
	sprintf(cmd2, "SAVESEG %s", name);
	response = 0;
	cpcmd(cmd1, NULL, 0, &response);
	if (response) {
		PRINT_ERR("segment_save: DEFSEG failed with response code %i\n",
			  response);
		goto out;
	}
	cpcmd(cmd2, NULL, 0, &response);
	if (response) {
		PRINT_ERR("segment_save: SAVESEG failed with response code %i\n",
			  response);
		goto out;
	}
out:
	mutex_unlock(&dcss_lock);
}

EXPORT_SYMBOL(segment_load);
EXPORT_SYMBOL(segment_unload);
EXPORT_SYMBOL(segment_save);
EXPORT_SYMBOL(segment_type);
EXPORT_SYMBOL(segment_modify_shared);