summaryrefslogtreecommitdiff
path: root/drivers/s390/char/zcore.c
blob: 047dd92ae804505ed9e363e526060b1822a6f102 (plain)
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
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
/*
 * zcore module to export memory content and register sets for creating system
 * dumps on SCSI disks (zfcpdump). The "zcore/mem" debugfs file shows the same
 * dump format as s390 standalone dumps.
 *
 * For more information please refer to Documentation/s390/zfcpdump.txt
 *
 * Copyright IBM Corp. 2003,2007
 * Author(s): Michael Holzheu
 */

#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/utsname.h>
#include <linux/debugfs.h>
#include <asm/ipl.h>
#include <asm/sclp.h>
#include <asm/setup.h>
#include <asm/sigp.h>
#include <asm/uaccess.h>
#include <asm/debug.h>
#include <asm/processor.h>
#include <asm/irqflags.h>
#include "sclp.h"

#define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x)
#define MSG(x...) printk( KERN_ALERT x )
#define ERROR_MSG(x...) printk ( KERN_ALERT "DUMP: " x )

#define TO_USER		0
#define TO_KERNEL	1

enum arch_id {
	ARCH_S390	= 0,
	ARCH_S390X	= 1,
};

/* dump system info */

struct sys_info {
	enum arch_id	arch;
	unsigned long	sa_base;
	u32		sa_size;
	int		cpu_map[NR_CPUS];
	unsigned long	mem_size;
	union save_area	lc_mask;
};

static struct sys_info sys_info;
static struct debug_info *zcore_dbf;
static int hsa_available;
static struct dentry *zcore_dir;
static struct dentry *zcore_file;

/*
 * Copy memory from HSA to kernel or user memory (not reentrant):
 *
 * @dest:  Kernel or user buffer where memory should be copied to
 * @src:   Start address within HSA where data should be copied
 * @count: Size of buffer, which should be copied
 * @mode:  Either TO_KERNEL or TO_USER
 */
static int memcpy_hsa(void *dest, unsigned long src, size_t count, int mode)
{
	int offs, blk_num;
	static char buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));

	if (count == 0)
		return 0;

	/* copy first block */
	offs = 0;
	if ((src % PAGE_SIZE) != 0) {
		blk_num = src / PAGE_SIZE + 2;
		if (sclp_sdias_copy(buf, blk_num, 1)) {
			TRACE("sclp_sdias_copy() failed\n");
			return -EIO;
		}
		offs = min((PAGE_SIZE - (src % PAGE_SIZE)), count);
		if (mode == TO_USER) {
			if (copy_to_user((__force __user void*) dest,
					 buf + (src % PAGE_SIZE), offs))
				return -EFAULT;
		} else
			memcpy(dest, buf + (src % PAGE_SIZE), offs);
	}
	if (offs == count)
		goto out;

	/* copy middle */
	for (; (offs + PAGE_SIZE) <= count; offs += PAGE_SIZE) {
		blk_num = (src + offs) / PAGE_SIZE + 2;
		if (sclp_sdias_copy(buf, blk_num, 1)) {
			TRACE("sclp_sdias_copy() failed\n");
			return -EIO;
		}
		if (mode == TO_USER) {
			if (copy_to_user((__force __user void*) dest + offs,
					 buf, PAGE_SIZE))
				return -EFAULT;
		} else
			memcpy(dest + offs, buf, PAGE_SIZE);
	}
	if (offs == count)
		goto out;

	/* copy last block */
	blk_num = (src + offs) / PAGE_SIZE + 2;
	if (sclp_sdias_copy(buf, blk_num, 1)) {
		TRACE("sclp_sdias_copy() failed\n");
		return -EIO;
	}
	if (mode == TO_USER) {
		if (copy_to_user((__force __user void*) dest + offs, buf,
				 PAGE_SIZE))
			return -EFAULT;
	} else
		memcpy(dest + offs, buf, count - offs);
out:
	return 0;
}

static int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count)
{
	return memcpy_hsa((void __force *) dest, src, count, TO_USER);
}

static int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count)
{
	return memcpy_hsa(dest, src, count, TO_KERNEL);
}

static int memcpy_real(void *dest, unsigned long src, size_t count)
{
	unsigned long flags;
	int rc = -EFAULT;
	register unsigned long _dest asm("2") = (unsigned long) dest;
	register unsigned long _len1 asm("3") = (unsigned long) count;
	register unsigned long _src  asm("4") = src;
	register unsigned long _len2 asm("5") = (unsigned long) count;

	if (count == 0)
		return 0;
	flags = __raw_local_irq_stnsm(0xf8UL); /* switch to real mode */
	asm volatile (
		"0:	mvcle	%1,%2,0x0\n"
		"1:	jo	0b\n"
		"	lhi	%0,0x0\n"
		"2:\n"
		EX_TABLE(1b,2b)
		: "+d" (rc), "+d" (_dest), "+d" (_src), "+d" (_len1),
		  "+d" (_len2), "=m" (*((long*)dest))
		: "m" (*((long*)src))
		: "cc", "memory");
	__raw_local_irq_ssm(flags);

	return rc;
}

static int memcpy_real_user(void __user *dest, unsigned long src, size_t count)
{
	static char buf[4096];
	int offs = 0, size;

	while (offs < count) {
		size = min(sizeof(buf), count - offs);
		if (memcpy_real(buf, src + offs, size))
			return -EFAULT;
		if (copy_to_user(dest + offs, buf, size))
			return -EFAULT;
		offs += size;
	}
	return 0;
}

#ifdef __s390x__
/*
 * Convert s390x (64 bit) cpu info to s390 (32 bit) cpu info
 */
static void __init s390x_to_s390_regs(union save_area *out, union save_area *in,
				      int cpu)
{
	int i;

	for (i = 0; i < 16; i++) {
		out->s390.gp_regs[i] = in->s390x.gp_regs[i] & 0x00000000ffffffff;
		out->s390.acc_regs[i] = in->s390x.acc_regs[i];
		out->s390.ctrl_regs[i] =
			in->s390x.ctrl_regs[i] & 0x00000000ffffffff;
	}
	/* locore for 31 bit has only space for fpregs 0,2,4,6 */
	out->s390.fp_regs[0] = in->s390x.fp_regs[0];
	out->s390.fp_regs[1] = in->s390x.fp_regs[2];
	out->s390.fp_regs[2] = in->s390x.fp_regs[4];
	out->s390.fp_regs[3] = in->s390x.fp_regs[6];
	memcpy(&(out->s390.psw[0]), &(in->s390x.psw[0]), 4);
	out->s390.psw[1] |= 0x8; /* set bit 12 */
	memcpy(&(out->s390.psw[4]),&(in->s390x.psw[12]), 4);
	out->s390.psw[4] |= 0x80; /* set (31bit) addressing bit */
	out->s390.pref_reg = in->s390x.pref_reg;
	out->s390.timer = in->s390x.timer;
	out->s390.clk_cmp = in->s390x.clk_cmp;
}

static void __init s390x_to_s390_save_areas(void)
{
	int i = 1;
	static union save_area tmp;

	while (zfcpdump_save_areas[i]) {
		s390x_to_s390_regs(&tmp, zfcpdump_save_areas[i], i);
		memcpy(zfcpdump_save_areas[i], &tmp, sizeof(tmp));
		i++;
	}
}

#endif /* __s390x__ */

static int __init init_cpu_info(enum arch_id arch)
{
	union save_area *sa;

	/* get info for boot cpu from lowcore, stored in the HSA */

	sa = kmalloc(sizeof(*sa), GFP_KERNEL);
	if (!sa)
		return -ENOMEM;
	if (memcpy_hsa_kernel(sa, sys_info.sa_base, sys_info.sa_size) < 0) {
		TRACE("could not copy from HSA\n");
		kfree(sa);
		return -EIO;
	}
	zfcpdump_save_areas[0] = sa;

#ifdef __s390x__
	/* convert s390x regs to s390, if we are dumping an s390 Linux */

	if (arch == ARCH_S390)
		s390x_to_s390_save_areas();
#endif

	return 0;
}

static DEFINE_MUTEX(zcore_mutex);

#define DUMP_VERSION	0x3
#define DUMP_MAGIC	0xa8190173618f23fdULL
#define DUMP_ARCH_S390X	2
#define DUMP_ARCH_S390	1
#define HEADER_SIZE	4096

/* dump header dumped according to s390 crash dump format */

struct zcore_header {
	u64 magic;
	u32 version;
	u32 header_size;
	u32 dump_level;
	u32 page_size;
	u64 mem_size;
	u64 mem_start;
	u64 mem_end;
	u32 num_pages;
	u32 pad1;
	u64 tod;
	cpuid_t cpu_id;
	u32 arch_id;
	u32 volnr;
	u32 build_arch;
	u64 rmem_size;
	char pad2[4016];
} __attribute__((packed,__aligned__(16)));

static struct zcore_header zcore_header = {
	.magic		= DUMP_MAGIC,
	.version	= DUMP_VERSION,
	.header_size	= 4096,
	.dump_level	= 0,
	.page_size	= PAGE_SIZE,
	.mem_start	= 0,
#ifdef __s390x__
	.build_arch	= DUMP_ARCH_S390X,
#else
	.build_arch	= DUMP_ARCH_S390,
#endif
};

/*
 * Copy lowcore info to buffer. Use map in order to copy only register parts.
 *
 * @buf:    User buffer
 * @sa:     Pointer to save area
 * @sa_off: Offset in save area to copy
 * @len:    Number of bytes to copy
 */
static int copy_lc(void __user *buf, void *sa, int sa_off, int len)
{
	int i;
	char *lc_mask = (char*)&sys_info.lc_mask;

	for (i = 0; i < len; i++) {
		if (!lc_mask[i + sa_off])
			continue;
		if (copy_to_user(buf + i, sa + sa_off + i, 1))
			return -EFAULT;
	}
	return 0;
}

/*
 * Copy lowcores info to memory, if necessary
 *
 * @buf:   User buffer
 * @addr:  Start address of buffer in dump memory
 * @count: Size of buffer
 */
static int zcore_add_lc(char __user *buf, unsigned long start, size_t count)
{
	unsigned long end;
	int i = 0;

	if (count == 0)
		return 0;

	end = start + count;
	while (zfcpdump_save_areas[i]) {
		unsigned long cp_start, cp_end; /* copy range */
		unsigned long sa_start, sa_end; /* save area range */
		unsigned long prefix;
		unsigned long sa_off, len, buf_off;

		if (sys_info.arch == ARCH_S390)
			prefix = zfcpdump_save_areas[i]->s390.pref_reg;
		else
			prefix = zfcpdump_save_areas[i]->s390x.pref_reg;

		sa_start = prefix + sys_info.sa_base;
		sa_end = prefix + sys_info.sa_base + sys_info.sa_size;

		if ((end < sa_start) || (start > sa_end))
			goto next;
		cp_start = max(start, sa_start);
		cp_end = min(end, sa_end);

		buf_off = cp_start - start;
		sa_off = cp_start - sa_start;
		len = cp_end - cp_start;

		TRACE("copy_lc for: %lx\n", start);
		if (copy_lc(buf + buf_off, zfcpdump_save_areas[i], sa_off, len))
			return -EFAULT;
next:
		i++;
	}
	return 0;
}

/*
 * Read routine for zcore character device
 * First 4K are dump header
 * Next 32MB are HSA Memory
 * Rest is read from absolute Memory
 */
static ssize_t zcore_read(struct file *file, char __user *buf, size_t count,
			  loff_t *ppos)
{
	unsigned long mem_start; /* Start address in memory */
	size_t mem_offs;	 /* Offset in dump memory */
	size_t hdr_count;	 /* Size of header part of output buffer */
	size_t size;
	int rc;

	mutex_lock(&zcore_mutex);

	if (*ppos > (sys_info.mem_size + HEADER_SIZE)) {
		rc = -EINVAL;
		goto fail;
	}

	count = min(count, (size_t) (sys_info.mem_size + HEADER_SIZE - *ppos));

	/* Copy dump header */
	if (*ppos < HEADER_SIZE) {
		size = min(count, (size_t) (HEADER_SIZE - *ppos));
		if (copy_to_user(buf, &zcore_header + *ppos, size)) {
			rc = -EFAULT;
			goto fail;
		}
		hdr_count = size;
		mem_start = 0;
	} else {
		hdr_count = 0;
		mem_start = *ppos - HEADER_SIZE;
	}

	mem_offs = 0;

	/* Copy from HSA data */
	if (*ppos < (ZFCPDUMP_HSA_SIZE + HEADER_SIZE)) {
		size = min((count - hdr_count), (size_t) (ZFCPDUMP_HSA_SIZE
			   - mem_start));
		rc = memcpy_hsa_user(buf + hdr_count, mem_start, size);
		if (rc)
			goto fail;

		mem_offs += size;
	}

	/* Copy from real mem */
	size = count - mem_offs - hdr_count;
	rc = memcpy_real_user(buf + hdr_count + mem_offs, mem_start + mem_offs,
			      size);
	if (rc)
		goto fail;

	/*
	 * Since s390 dump analysis tools like lcrash or crash
	 * expect register sets in the prefix pages of the cpus,
	 * we copy them into the read buffer, if necessary.
	 * buf + hdr_count: Start of memory part of output buffer
	 * mem_start: Start memory address to copy from
	 * count - hdr_count: Size of memory area to copy
	 */
	if (zcore_add_lc(buf + hdr_count, mem_start, count - hdr_count)) {
		rc = -EFAULT;
		goto fail;
	}
	*ppos += count;
fail:
	mutex_unlock(&zcore_mutex);
	return (rc < 0) ? rc : count;
}

static int zcore_open(struct inode *inode, struct file *filp)
{
	if (!hsa_available)
		return -ENODATA;
	else
		return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
}

static int zcore_release(struct inode *inode, struct file *filep)
{
	diag308(DIAG308_REL_HSA, NULL);
	hsa_available = 0;
	return 0;
}

static loff_t zcore_lseek(struct file *file, loff_t offset, int orig)
{
	loff_t rc;

	mutex_lock(&zcore_mutex);
	switch (orig) {
	case 0:
		file->f_pos = offset;
		rc = file->f_pos;
		break;
	case 1:
		file->f_pos += offset;
		rc = file->f_pos;
		break;
	default:
		rc = -EINVAL;
	}
	mutex_unlock(&zcore_mutex);
	return rc;
}

static const struct file_operations zcore_fops = {
	.owner		= THIS_MODULE,
	.llseek		= zcore_lseek,
	.read		= zcore_read,
	.open		= zcore_open,
	.release	= zcore_release,
};


static void __init set_s390_lc_mask(union save_area *map)
{
	memset(&map->s390.ext_save, 0xff, sizeof(map->s390.ext_save));
	memset(&map->s390.timer, 0xff, sizeof(map->s390.timer));
	memset(&map->s390.clk_cmp, 0xff, sizeof(map->s390.clk_cmp));
	memset(&map->s390.psw, 0xff, sizeof(map->s390.psw));
	memset(&map->s390.pref_reg, 0xff, sizeof(map->s390.pref_reg));
	memset(&map->s390.acc_regs, 0xff, sizeof(map->s390.acc_regs));
	memset(&map->s390.fp_regs, 0xff, sizeof(map->s390.fp_regs));
	memset(&map->s390.gp_regs, 0xff, sizeof(map->s390.gp_regs));
	memset(&map->s390.ctrl_regs, 0xff, sizeof(map->s390.ctrl_regs));
}

static void __init set_s390x_lc_mask(union save_area *map)
{
	memset(&map->s390x.fp_regs, 0xff, sizeof(map->s390x.fp_regs));
	memset(&map->s390x.gp_regs, 0xff, sizeof(map->s390x.gp_regs));
	memset(&map->s390x.psw, 0xff, sizeof(map->s390x.psw));
	memset(&map->s390x.pref_reg, 0xff, sizeof(map->s390x.pref_reg));
	memset(&map->s390x.fp_ctrl_reg, 0xff, sizeof(map->s390x.fp_ctrl_reg));
	memset(&map->s390x.tod_reg, 0xff, sizeof(map->s390x.tod_reg));
	memset(&map->s390x.timer, 0xff, sizeof(map->s390x.timer));
	memset(&map->s390x.clk_cmp, 0xff, sizeof(map->s390x.clk_cmp));
	memset(&map->s390x.acc_regs, 0xff, sizeof(map->s390x.acc_regs));
	memset(&map->s390x.ctrl_regs, 0xff, sizeof(map->s390x.ctrl_regs));
}

/*
 * Initialize dump globals for a given architecture
 */
static int __init sys_info_init(enum arch_id arch)
{
	int rc;

	switch (arch) {
	case ARCH_S390X:
		MSG("DETECTED 'S390X (64 bit) OS'\n");
		sys_info.sa_base = SAVE_AREA_BASE_S390X;
		sys_info.sa_size = sizeof(struct save_area_s390x);
		set_s390x_lc_mask(&sys_info.lc_mask);
		break;
	case ARCH_S390:
		MSG("DETECTED 'S390 (32 bit) OS'\n");
		sys_info.sa_base = SAVE_AREA_BASE_S390;
		sys_info.sa_size = sizeof(struct save_area_s390);
		set_s390_lc_mask(&sys_info.lc_mask);
		break;
	default:
		ERROR_MSG("unknown architecture 0x%x.\n",arch);
		return -EINVAL;
	}
	sys_info.arch = arch;
	rc = init_cpu_info(arch);
	if (rc)
		return rc;
	sys_info.mem_size = real_memory_size;

	return 0;
}

static int __init check_sdias(void)
{
	int rc, act_hsa_size;

	rc = sclp_sdias_blk_count();
	if (rc < 0) {
		TRACE("Could not determine HSA size\n");
		return rc;
	}
	act_hsa_size = (rc - 1) * PAGE_SIZE;
	if (act_hsa_size < ZFCPDUMP_HSA_SIZE) {
		TRACE("HSA size too small: %i\n", act_hsa_size);
		return -EINVAL;
	}
	return 0;
}

static void __init zcore_header_init(int arch, struct zcore_header *hdr)
{
	if (arch == ARCH_S390X)
		hdr->arch_id = DUMP_ARCH_S390X;
	else
		hdr->arch_id = DUMP_ARCH_S390;
	hdr->mem_size = sys_info.mem_size;
	hdr->rmem_size = sys_info.mem_size;
	hdr->mem_end = sys_info.mem_size;
	hdr->num_pages = sys_info.mem_size / PAGE_SIZE;
	hdr->tod = get_clock();
	get_cpu_id(&hdr->cpu_id);
}

static int __init zcore_init(void)
{
	unsigned char arch;
	int rc;

	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
		return -ENODATA;

	zcore_dbf = debug_register("zcore", 4, 1, 4 * sizeof(long));
	debug_register_view(zcore_dbf, &debug_sprintf_view);
	debug_set_level(zcore_dbf, 6);

	TRACE("devno:  %x\n", ipl_info.data.fcp.dev_id.devno);
	TRACE("wwpn:   %llx\n", (unsigned long long) ipl_info.data.fcp.wwpn);
	TRACE("lun:    %llx\n", (unsigned long long) ipl_info.data.fcp.lun);

	rc = sclp_sdias_init();
	if (rc)
		goto fail;

	rc = check_sdias();
	if (rc)
		goto fail;

	rc = memcpy_hsa_kernel(&arch, __LC_AR_MODE_ID, 1);
	if (rc)
		goto fail;

#ifndef __s390x__
	if (arch == ARCH_S390X) {
		ERROR_MSG("32 bit dumper can't dump 64 bit system!\n");
		rc = -EINVAL;
		goto fail;
	}
#endif

	rc = sys_info_init(arch);
	if (rc)
		goto fail;

	zcore_header_init(arch, &zcore_header);

	zcore_dir = debugfs_create_dir("zcore" , NULL);
	if (!zcore_dir) {
		rc = -ENOMEM;
		goto fail;
	}
	zcore_file = debugfs_create_file("mem", S_IRUSR, zcore_dir, NULL,
					 &zcore_fops);
	if (!zcore_file) {
		debugfs_remove(zcore_dir);
		rc = -ENOMEM;
		goto fail;
	}
	hsa_available = 1;
	return 0;

fail:
	diag308(DIAG308_REL_HSA, NULL);
	return rc;
}

static void __exit zcore_exit(void)
{
	debug_unregister(zcore_dbf);
	sclp_sdias_exit();
	diag308(DIAG308_REL_HSA, NULL);
}

MODULE_AUTHOR("Copyright IBM Corp. 2003,2007");
MODULE_DESCRIPTION("zcore module for zfcpdump support");
MODULE_LICENSE("GPL");

subsys_initcall(zcore_init);
module_exit(zcore_exit);