summaryrefslogtreecommitdiff
path: root/drivers/s390/char/zcore.c
blob: 5043ecfa1fbcfecf10cc8c2ae34dd1b0e591d6c1 (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
/*
 * 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, 2008
 * Author(s): Michael Holzheu
 */

#define KMSG_COMPONENT "zdump"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/miscdevice.h>
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/memblock.h>

#include <asm/asm-offsets.h>
#include <asm/ipl.h>
#include <asm/sclp.h>
#include <asm/setup.h>
#include <asm/uaccess.h>
#include <asm/debug.h>
#include <asm/processor.h>
#include <asm/irqflags.h>
#include <asm/checksum.h>
#include <asm/os_info.h>
#include <asm/switch_to.h>
#include "sclp.h"

#define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x)

#define CHUNK_INFO_SIZE	34 /* 2 16-byte char, each followed by blank */

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

struct ipib_info {
	unsigned long	ipib;
	u32		checksum;
}  __attribute__((packed));

static struct debug_info *zcore_dbf;
static int hsa_available;
static struct dentry *zcore_dir;
static struct dentry *zcore_memmap_file;
static struct dentry *zcore_reipl_file;
static struct dentry *zcore_hsa_file;
static struct ipl_parameter_block *ipl_block;

static char hsa_buf[PAGE_SIZE] __aligned(PAGE_SIZE);

/*
 * Copy memory from HSA to user memory (not reentrant):
 *
 * @dest:  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
 */
int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count)
{
	unsigned long offset, bytes;

	if (!hsa_available)
		return -ENODATA;

	while (count) {
		if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) {
			TRACE("sclp_sdias_copy() failed\n");
			return -EIO;
		}
		offset = src % PAGE_SIZE;
		bytes = min(PAGE_SIZE - offset, count);
		if (copy_to_user(dest, hsa_buf + offset, bytes))
			return -EFAULT;
		src += bytes;
		dest += bytes;
		count -= bytes;
	}
	return 0;
}

/*
 * Copy memory from HSA to kernel 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
 */
int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count)
{
	unsigned long offset, bytes;

	if (!hsa_available)
		return -ENODATA;

	while (count) {
		if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) {
			TRACE("sclp_sdias_copy() failed\n");
			return -EIO;
		}
		offset = src % PAGE_SIZE;
		bytes = min(PAGE_SIZE - offset, count);
		memcpy(dest, hsa_buf + offset, bytes);
		src += bytes;
		dest += bytes;
		count -= bytes;
	}
	return 0;
}

static int __init init_cpu_info(void)
{
	struct save_area *sa;

	/* get info for boot cpu from lowcore, stored in the HSA */
	sa = save_area_boot_cpu();
	if (!sa)
		return -ENOMEM;
	if (memcpy_hsa_kernel(hsa_buf, __LC_FPREGS_SAVE_AREA, 512) < 0) {
		TRACE("could not copy from HSA\n");
		return -EIO;
	}
	save_area_add_regs(sa, hsa_buf); /* vx registers are saved in smp.c */
	return 0;
}

/*
 * Release the HSA
 */
static void release_hsa(void)
{
	diag308(DIAG308_REL_HSA, NULL);
	hsa_available = 0;
}

static ssize_t zcore_memmap_read(struct file *filp, char __user *buf,
				 size_t count, loff_t *ppos)
{
	return simple_read_from_buffer(buf, count, ppos, filp->private_data,
				       memblock.memory.cnt * CHUNK_INFO_SIZE);
}

static int zcore_memmap_open(struct inode *inode, struct file *filp)
{
	struct memblock_region *reg;
	char *buf;
	int i = 0;

	buf = kzalloc(memblock.memory.cnt * CHUNK_INFO_SIZE, GFP_KERNEL);
	if (!buf) {
		return -ENOMEM;
	}
	for_each_memblock(memory, reg) {
		sprintf(buf + (i++ * CHUNK_INFO_SIZE), "%016llx %016llx ",
			(unsigned long long) reg->base,
			(unsigned long long) reg->size);
	}
	filp->private_data = buf;
	return nonseekable_open(inode, filp);
}

static int zcore_memmap_release(struct inode *inode, struct file *filp)
{
	kfree(filp->private_data);
	return 0;
}

static const struct file_operations zcore_memmap_fops = {
	.owner		= THIS_MODULE,
	.read		= zcore_memmap_read,
	.open		= zcore_memmap_open,
	.release	= zcore_memmap_release,
	.llseek		= no_llseek,
};

static ssize_t zcore_reipl_write(struct file *filp, const char __user *buf,
				 size_t count, loff_t *ppos)
{
	if (ipl_block) {
		diag308(DIAG308_SET, ipl_block);
		diag308(DIAG308_IPL, NULL);
	}
	return count;
}

static int zcore_reipl_open(struct inode *inode, struct file *filp)
{
	return nonseekable_open(inode, filp);
}

static int zcore_reipl_release(struct inode *inode, struct file *filp)
{
	return 0;
}

static const struct file_operations zcore_reipl_fops = {
	.owner		= THIS_MODULE,
	.write		= zcore_reipl_write,
	.open		= zcore_reipl_open,
	.release	= zcore_reipl_release,
	.llseek		= no_llseek,
};

static ssize_t zcore_hsa_read(struct file *filp, char __user *buf,
			      size_t count, loff_t *ppos)
{
	static char str[18];

	if (hsa_available)
		snprintf(str, sizeof(str), "%lx\n", sclp.hsa_size);
	else
		snprintf(str, sizeof(str), "0\n");
	return simple_read_from_buffer(buf, count, ppos, str, strlen(str));
}

static ssize_t zcore_hsa_write(struct file *filp, const char __user *buf,
			       size_t count, loff_t *ppos)
{
	char value;

	if (*ppos != 0)
		return -EPIPE;
	if (copy_from_user(&value, buf, 1))
		return -EFAULT;
	if (value != '0')
		return -EINVAL;
	release_hsa();
	return count;
}

static const struct file_operations zcore_hsa_fops = {
	.owner		= THIS_MODULE,
	.write		= zcore_hsa_write,
	.read		= zcore_hsa_read,
	.open		= nonseekable_open,
	.llseek		= no_llseek,
};

static int __init check_sdias(void)
{
	if (!sclp.hsa_size) {
		TRACE("Could not determine HSA size\n");
		return -ENODEV;
	}
	return 0;
}

/*
 * Provide IPL parameter information block from either HSA or memory
 * for future reipl
 */
static int __init zcore_reipl_init(void)
{
	struct ipib_info ipib_info;
	int rc;

	rc = memcpy_hsa_kernel(&ipib_info, __LC_DUMP_REIPL, sizeof(ipib_info));
	if (rc)
		return rc;
	if (ipib_info.ipib == 0)
		return 0;
	ipl_block = (void *) __get_free_page(GFP_KERNEL);
	if (!ipl_block)
		return -ENOMEM;
	if (ipib_info.ipib < sclp.hsa_size)
		rc = memcpy_hsa_kernel(ipl_block, ipib_info.ipib, PAGE_SIZE);
	else
		rc = memcpy_real(ipl_block, (void *) ipib_info.ipib, PAGE_SIZE);
	if (rc || csum_partial(ipl_block, ipl_block->hdr.len, 0) !=
	    ipib_info.checksum) {
		TRACE("Checksum does not match\n");
		free_page((unsigned long) ipl_block);
		ipl_block = NULL;
	}
	return 0;
}

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

	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
		return -ENODATA;
	if (OLDMEM_BASE)
		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;
	hsa_available = 1;

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

	if (arch == ARCH_S390) {
		pr_alert("The 64-bit dump tool cannot be used for a "
			 "32-bit system\n");
		rc = -EINVAL;
		goto fail;
	}

	pr_alert("DETECTED 'S390X (64 bit) OS'\n");
	rc = init_cpu_info();
	if (rc)
		goto fail;

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

	zcore_dir = debugfs_create_dir("zcore" , NULL);
	if (!zcore_dir) {
		rc = -ENOMEM;
		goto fail;
	}
	zcore_memmap_file = debugfs_create_file("memmap", S_IRUSR, zcore_dir,
						NULL, &zcore_memmap_fops);
	if (!zcore_memmap_file) {
		rc = -ENOMEM;
		goto fail_dir;
	}
	zcore_reipl_file = debugfs_create_file("reipl", S_IRUSR, zcore_dir,
						NULL, &zcore_reipl_fops);
	if (!zcore_reipl_file) {
		rc = -ENOMEM;
		goto fail_memmap_file;
	}
	zcore_hsa_file = debugfs_create_file("hsa", S_IRUSR|S_IWUSR, zcore_dir,
					     NULL, &zcore_hsa_fops);
	if (!zcore_hsa_file) {
		rc = -ENOMEM;
		goto fail_reipl_file;
	}
	return 0;

fail_reipl_file:
	debugfs_remove(zcore_reipl_file);
fail_memmap_file:
	debugfs_remove(zcore_memmap_file);
fail_dir:
	debugfs_remove(zcore_dir);
fail:
	diag308(DIAG308_REL_HSA, NULL);
	return rc;
}

static void __exit zcore_exit(void)
{
	debug_unregister(zcore_dbf);
	sclp_sdias_exit();
	free_page((unsigned long) ipl_block);
	debugfs_remove(zcore_hsa_file);
	debugfs_remove(zcore_reipl_file);
	debugfs_remove(zcore_memmap_file);
	debugfs_remove(zcore_dir);
	diag308(DIAG308_REL_HSA, NULL);
}

MODULE_AUTHOR("Copyright IBM Corp. 2003,2008");
MODULE_DESCRIPTION("zcore module for zfcpdump support");
MODULE_LICENSE("GPL");

subsys_initcall(zcore_init);
module_exit(zcore_exit);