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Committer: Michael Beasley <mike@snafu.setup>
[mikesnafu-overlay.git] / drivers / s390 / char / zcore.c
blobf523501e6e6c60bb25bbf80077847f87edcfc23a
1 /*
2 * zcore module to export memory content and register sets for creating system
3 * dumps on SCSI disks (zfcpdump). The "zcore/mem" debugfs file shows the same
4 * dump format as s390 standalone dumps.
5 *
6 * For more information please refer to Documentation/s390/zfcpdump.txt
7 *
8 * Copyright IBM Corp. 2003,2007
9 * Author(s): Michael Holzheu
10 */
11
12 #include <linux/init.h>
13 #include <linux/miscdevice.h>
14 #include <linux/utsname.h>
15 #include <linux/debugfs.h>
16 #include <asm/ipl.h>
17 #include <asm/sclp.h>
18 #include <asm/setup.h>
19 #include <asm/sigp.h>
20 #include <asm/uaccess.h>
21 #include <asm/debug.h>
22 #include <asm/processor.h>
23 #include <asm/irqflags.h>
24 #include "sclp.h"
25
26 #define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x)
27 #define MSG(x...) printk( KERN_ALERT x )
28 #define ERROR_MSG(x...) printk ( KERN_ALERT "DUMP: " x )
29
30 #define TO_USER 0
31 #define TO_KERNEL 1
32
33 enum arch_id {
34 ARCH_S390 = 0,
35 ARCH_S390X = 1,
36 };
37
38 /* dump system info */
39
40 struct sys_info {
41 enum arch_id arch;
42 unsigned long sa_base;
43 u32 sa_size;
44 int cpu_map[NR_CPUS];
45 unsigned long mem_size;
46 union save_area lc_mask;
47 };
48
49 static struct sys_info sys_info;
50 static struct debug_info *zcore_dbf;
51 static int hsa_available;
52 static struct dentry *zcore_dir;
53 static struct dentry *zcore_file;
54
55 /*
56 * Copy memory from HSA to kernel or user memory (not reentrant):
57 *
58 * @dest: Kernel or user buffer where memory should be copied to
59 * @src: Start address within HSA where data should be copied
60 * @count: Size of buffer, which should be copied
61 * @mode: Either TO_KERNEL or TO_USER
62 */
63 static int memcpy_hsa(void *dest, unsigned long src, size_t count, int mode)
64 {
65 int offs, blk_num;
66 static char buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
67
68 if (count == 0)
69 return 0;
70
71 /* copy first block */
72 offs = 0;
73 if ((src % PAGE_SIZE) != 0) {
74 blk_num = src / PAGE_SIZE + 2;
75 if (sclp_sdias_copy(buf, blk_num, 1)) {
76 TRACE("sclp_sdias_copy() failed\n");
77 return -EIO;
78 }
79 offs = min((PAGE_SIZE - (src % PAGE_SIZE)), count);
80 if (mode == TO_USER) {
81 if (copy_to_user((__force __user void*) dest,
82 buf + (src % PAGE_SIZE), offs))
83 return -EFAULT;
84 } else
85 memcpy(dest, buf + (src % PAGE_SIZE), offs);
86 }
87 if (offs == count)
88 goto out;
89
90 /* copy middle */
91 for (; (offs + PAGE_SIZE) <= count; offs += PAGE_SIZE) {
92 blk_num = (src + offs) / PAGE_SIZE + 2;
93 if (sclp_sdias_copy(buf, blk_num, 1)) {
94 TRACE("sclp_sdias_copy() failed\n");
95 return -EIO;
96 }
97 if (mode == TO_USER) {
98 if (copy_to_user((__force __user void*) dest + offs,
99 buf, PAGE_SIZE))
100 return -EFAULT;
101 } else
102 memcpy(dest + offs, buf, PAGE_SIZE);
103 }
104 if (offs == count)
105 goto out;
106
107 /* copy last block */
108 blk_num = (src + offs) / PAGE_SIZE + 2;
109 if (sclp_sdias_copy(buf, blk_num, 1)) {
110 TRACE("sclp_sdias_copy() failed\n");
111 return -EIO;
112 }
113 if (mode == TO_USER) {
114 if (copy_to_user((__force __user void*) dest + offs, buf,
115 PAGE_SIZE))
116 return -EFAULT;
117 } else
118 memcpy(dest + offs, buf, count - offs);
119 out:
120 return 0;
121 }
122
123 static int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count)
124 {
125 return memcpy_hsa((void __force *) dest, src, count, TO_USER);
126 }
127
128 static int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count)
129 {
130 return memcpy_hsa(dest, src, count, TO_KERNEL);
131 }
132
133 static int memcpy_real(void *dest, unsigned long src, size_t count)
134 {
135 unsigned long flags;
136 int rc = -EFAULT;
137 register unsigned long _dest asm("2") = (unsigned long) dest;
138 register unsigned long _len1 asm("3") = (unsigned long) count;
139 register unsigned long _src asm("4") = src;
140 register unsigned long _len2 asm("5") = (unsigned long) count;
141
142 if (count == 0)
143 return 0;
144 flags = __raw_local_irq_stnsm(0xf8UL); /* switch to real mode */
145 asm volatile (
146 "0: mvcle %1,%2,0x0\n"
147 "1: jo 0b\n"
148 " lhi %0,0x0\n"
149 "2:\n"
150 EX_TABLE(1b,2b)
151 : "+d" (rc), "+d" (_dest), "+d" (_src), "+d" (_len1),
152 "+d" (_len2), "=m" (*((long*)dest))
153 : "m" (*((long*)src))
154 : "cc", "memory");
155 __raw_local_irq_ssm(flags);
156
157 return rc;
158 }
159
160 static int memcpy_real_user(void __user *dest, unsigned long src, size_t count)
161 {
162 static char buf[4096];
163 int offs = 0, size;
164
165 while (offs < count) {
166 size = min(sizeof(buf), count - offs);
167 if (memcpy_real(buf, src + offs, size))
168 return -EFAULT;
169 if (copy_to_user(dest + offs, buf, size))
170 return -EFAULT;
171 offs += size;
172 }
173 return 0;
174 }
175
176 #ifdef __s390x__
177 /*
178 * Convert s390x (64 bit) cpu info to s390 (32 bit) cpu info
179 */
180 static void __init s390x_to_s390_regs(union save_area *out, union save_area *in,
181 int cpu)
182 {
183 int i;
184
185 for (i = 0; i < 16; i++) {
186 out->s390.gp_regs[i] = in->s390x.gp_regs[i] & 0x00000000ffffffff;
187 out->s390.acc_regs[i] = in->s390x.acc_regs[i];
188 out->s390.ctrl_regs[i] =
189 in->s390x.ctrl_regs[i] & 0x00000000ffffffff;
190 }
191 /* locore for 31 bit has only space for fpregs 0,2,4,6 */
192 out->s390.fp_regs[0] = in->s390x.fp_regs[0];
193 out->s390.fp_regs[1] = in->s390x.fp_regs[2];
194 out->s390.fp_regs[2] = in->s390x.fp_regs[4];
195 out->s390.fp_regs[3] = in->s390x.fp_regs[6];
196 memcpy(&(out->s390.psw[0]), &(in->s390x.psw[0]), 4);
197 out->s390.psw[1] |= 0x8; /* set bit 12 */
198 memcpy(&(out->s390.psw[4]),&(in->s390x.psw[12]), 4);
199 out->s390.psw[4] |= 0x80; /* set (31bit) addressing bit */
200 out->s390.pref_reg = in->s390x.pref_reg;
201 out->s390.timer = in->s390x.timer;
202 out->s390.clk_cmp = in->s390x.clk_cmp;
203 }
204
205 static void __init s390x_to_s390_save_areas(void)
206 {
207 int i = 1;
208 static union save_area tmp;
209
210 while (zfcpdump_save_areas[i]) {
211 s390x_to_s390_regs(&tmp, zfcpdump_save_areas[i], i);
212 memcpy(zfcpdump_save_areas[i], &tmp, sizeof(tmp));
213 i++;
214 }
215 }
216
217 #endif /* __s390x__ */
218
219 static int __init init_cpu_info(enum arch_id arch)
220 {
221 union save_area *sa;
222
223 /* get info for boot cpu from lowcore, stored in the HSA */
224
225 sa = kmalloc(sizeof(*sa), GFP_KERNEL);
226 if (!sa) {
227 ERROR_MSG("kmalloc failed: %s: %i\n",__FUNCTION__, __LINE__);
228 return -ENOMEM;
229 }
230 if (memcpy_hsa_kernel(sa, sys_info.sa_base, sys_info.sa_size) < 0) {
231 ERROR_MSG("could not copy from HSA\n");
232 kfree(sa);
233 return -EIO;
234 }
235 zfcpdump_save_areas[0] = sa;
236
237 #ifdef __s390x__
238 /* convert s390x regs to s390, if we are dumping an s390 Linux */
239
240 if (arch == ARCH_S390)
241 s390x_to_s390_save_areas();
242 #endif
243
244 return 0;
245 }
246
247 static DEFINE_MUTEX(zcore_mutex);
248
249 #define DUMP_VERSION 0x3
250 #define DUMP_MAGIC 0xa8190173618f23fdULL
251 #define DUMP_ARCH_S390X 2
252 #define DUMP_ARCH_S390 1
253 #define HEADER_SIZE 4096
254
255 /* dump header dumped according to s390 crash dump format */
256
257 struct zcore_header {
258 u64 magic;
259 u32 version;
260 u32 header_size;
261 u32 dump_level;
262 u32 page_size;
263 u64 mem_size;
264 u64 mem_start;
265 u64 mem_end;
266 u32 num_pages;
267 u32 pad1;
268 u64 tod;
269 cpuid_t cpu_id;
270 u32 arch_id;
271 u32 volnr;
272 u32 build_arch;
273 u64 rmem_size;
274 char pad2[4016];
275 } __attribute__((packed,__aligned__(16)));
276
277 static struct zcore_header zcore_header = {
278 .magic = DUMP_MAGIC,
279 .version = DUMP_VERSION,
280 .header_size = 4096,
281 .dump_level = 0,
282 .page_size = PAGE_SIZE,
283 .mem_start = 0,
284 #ifdef __s390x__
285 .build_arch = DUMP_ARCH_S390X,
286 #else
287 .build_arch = DUMP_ARCH_S390,
288 #endif
289 };
290
291 /*
292 * Copy lowcore info to buffer. Use map in order to copy only register parts.
293 *
294 * @buf: User buffer
295 * @sa: Pointer to save area
296 * @sa_off: Offset in save area to copy
297 * @len: Number of bytes to copy
298 */
299 static int copy_lc(void __user *buf, void *sa, int sa_off, int len)
300 {
301 int i;
302 char *lc_mask = (char*)&sys_info.lc_mask;
303
304 for (i = 0; i < len; i++) {
305 if (!lc_mask[i + sa_off])
306 continue;
307 if (copy_to_user(buf + i, sa + sa_off + i, 1))
308 return -EFAULT;
309 }
310 return 0;
311 }
312
313 /*
314 * Copy lowcores info to memory, if necessary
315 *
316 * @buf: User buffer
317 * @addr: Start address of buffer in dump memory
318 * @count: Size of buffer
319 */
320 static int zcore_add_lc(char __user *buf, unsigned long start, size_t count)
321 {
322 unsigned long end;
323 int i = 0;
324
325 if (count == 0)
326 return 0;
327
328 end = start + count;
329 while (zfcpdump_save_areas[i]) {
330 unsigned long cp_start, cp_end; /* copy range */
331 unsigned long sa_start, sa_end; /* save area range */
332 unsigned long prefix;
333 unsigned long sa_off, len, buf_off;
334
335 if (sys_info.arch == ARCH_S390)
336 prefix = zfcpdump_save_areas[i]->s390.pref_reg;
337 else
338 prefix = zfcpdump_save_areas[i]->s390x.pref_reg;
339
340 sa_start = prefix + sys_info.sa_base;
341 sa_end = prefix + sys_info.sa_base + sys_info.sa_size;
342
343 if ((end < sa_start) || (start > sa_end))
344 goto next;
345 cp_start = max(start, sa_start);
346 cp_end = min(end, sa_end);
347
348 buf_off = cp_start - start;
349 sa_off = cp_start - sa_start;
350 len = cp_end - cp_start;
351
352 TRACE("copy_lc for: %lx\n", start);
353 if (copy_lc(buf + buf_off, zfcpdump_save_areas[i], sa_off, len))
354 return -EFAULT;
355 next:
356 i++;
357 }
358 return 0;
359 }
360
361 /*
362 * Read routine for zcore character device
363 * First 4K are dump header
364 * Next 32MB are HSA Memory
365 * Rest is read from absolute Memory
366 */
367 static ssize_t zcore_read(struct file *file, char __user *buf, size_t count,
368 loff_t *ppos)
369 {
370 unsigned long mem_start; /* Start address in memory */
371 size_t mem_offs; /* Offset in dump memory */
372 size_t hdr_count; /* Size of header part of output buffer */
373 size_t size;
374 int rc;
375
376 mutex_lock(&zcore_mutex);
377
378 if (*ppos > (sys_info.mem_size + HEADER_SIZE)) {
379 rc = -EINVAL;
380 goto fail;
381 }
382
383 count = min(count, (size_t) (sys_info.mem_size + HEADER_SIZE - *ppos));
384
385 /* Copy dump header */
386 if (*ppos < HEADER_SIZE) {
387 size = min(count, (size_t) (HEADER_SIZE - *ppos));
388 if (copy_to_user(buf, &zcore_header + *ppos, size)) {
389 rc = -EFAULT;
390 goto fail;
391 }
392 hdr_count = size;
393 mem_start = 0;
394 } else {
395 hdr_count = 0;
396 mem_start = *ppos - HEADER_SIZE;
397 }
398
399 mem_offs = 0;
400
401 /* Copy from HSA data */
402 if (*ppos < (ZFCPDUMP_HSA_SIZE + HEADER_SIZE)) {
403 size = min((count - hdr_count), (size_t) (ZFCPDUMP_HSA_SIZE
404 - mem_start));
405 rc = memcpy_hsa_user(buf + hdr_count, mem_start, size);
406 if (rc)
407 goto fail;
408
409 mem_offs += size;
410 }
411
412 /* Copy from real mem */
413 size = count - mem_offs - hdr_count;
414 rc = memcpy_real_user(buf + hdr_count + mem_offs, mem_start + mem_offs,
415 size);
416 if (rc)
417 goto fail;
418
419 /*
420 * Since s390 dump analysis tools like lcrash or crash
421 * expect register sets in the prefix pages of the cpus,
422 * we copy them into the read buffer, if necessary.
423 * buf + hdr_count: Start of memory part of output buffer
424 * mem_start: Start memory address to copy from
425 * count - hdr_count: Size of memory area to copy
426 */
427 if (zcore_add_lc(buf + hdr_count, mem_start, count - hdr_count)) {
428 rc = -EFAULT;
429 goto fail;
430 }
431 *ppos += count;
432 fail:
433 mutex_unlock(&zcore_mutex);
434 return (rc < 0) ? rc : count;
435 }
436
437 static int zcore_open(struct inode *inode, struct file *filp)
438 {
439 if (!hsa_available)
440 return -ENODATA;
441 else
442 return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
443 }
444
445 static int zcore_release(struct inode *inode, struct file *filep)
446 {
447 diag308(DIAG308_REL_HSA, NULL);
448 hsa_available = 0;
449 return 0;
450 }
451
452 static loff_t zcore_lseek(struct file *file, loff_t offset, int orig)
453 {
454 loff_t rc;
455
456 mutex_lock(&zcore_mutex);
457 switch (orig) {
458 case 0:
459 file->f_pos = offset;
460 rc = file->f_pos;
461 break;
462 case 1:
463 file->f_pos += offset;
464 rc = file->f_pos;
465 break;
466 default:
467 rc = -EINVAL;
468 }
469 mutex_unlock(&zcore_mutex);
470 return rc;
471 }
472
473 static const struct file_operations zcore_fops = {
474 .owner = THIS_MODULE,
475 .llseek = zcore_lseek,
476 .read = zcore_read,
477 .open = zcore_open,
478 .release = zcore_release,
479 };
480
481
482 static void __init set_s390_lc_mask(union save_area *map)
483 {
484 memset(&map->s390.ext_save, 0xff, sizeof(map->s390.ext_save));
485 memset(&map->s390.timer, 0xff, sizeof(map->s390.timer));
486 memset(&map->s390.clk_cmp, 0xff, sizeof(map->s390.clk_cmp));
487 memset(&map->s390.psw, 0xff, sizeof(map->s390.psw));
488 memset(&map->s390.pref_reg, 0xff, sizeof(map->s390.pref_reg));
489 memset(&map->s390.acc_regs, 0xff, sizeof(map->s390.acc_regs));
490 memset(&map->s390.fp_regs, 0xff, sizeof(map->s390.fp_regs));
491 memset(&map->s390.gp_regs, 0xff, sizeof(map->s390.gp_regs));
492 memset(&map->s390.ctrl_regs, 0xff, sizeof(map->s390.ctrl_regs));
493 }
494
495 static void __init set_s390x_lc_mask(union save_area *map)
496 {
497 memset(&map->s390x.fp_regs, 0xff, sizeof(map->s390x.fp_regs));
498 memset(&map->s390x.gp_regs, 0xff, sizeof(map->s390x.gp_regs));
499 memset(&map->s390x.psw, 0xff, sizeof(map->s390x.psw));
500 memset(&map->s390x.pref_reg, 0xff, sizeof(map->s390x.pref_reg));
501 memset(&map->s390x.fp_ctrl_reg, 0xff, sizeof(map->s390x.fp_ctrl_reg));
502 memset(&map->s390x.tod_reg, 0xff, sizeof(map->s390x.tod_reg));
503 memset(&map->s390x.timer, 0xff, sizeof(map->s390x.timer));
504 memset(&map->s390x.clk_cmp, 0xff, sizeof(map->s390x.clk_cmp));
505 memset(&map->s390x.acc_regs, 0xff, sizeof(map->s390x.acc_regs));
506 memset(&map->s390x.ctrl_regs, 0xff, sizeof(map->s390x.ctrl_regs));
507 }
508
509 /*
510 * Initialize dump globals for a given architecture
511 */
512 static int __init sys_info_init(enum arch_id arch)
513 {
514 switch (arch) {
515 case ARCH_S390X:
516 MSG("DETECTED 'S390X (64 bit) OS'\n");
517 sys_info.sa_base = SAVE_AREA_BASE_S390X;
518 sys_info.sa_size = sizeof(struct save_area_s390x);
519 set_s390x_lc_mask(&sys_info.lc_mask);
520 break;
521 case ARCH_S390:
522 MSG("DETECTED 'S390 (32 bit) OS'\n");
523 sys_info.sa_base = SAVE_AREA_BASE_S390;
524 sys_info.sa_size = sizeof(struct save_area_s390);
525 set_s390_lc_mask(&sys_info.lc_mask);
526 break;
527 default:
528 ERROR_MSG("unknown architecture 0x%x.\n",arch);
529 return -EINVAL;
530 }
531 sys_info.arch = arch;
532 if (init_cpu_info(arch)) {
533 ERROR_MSG("get cpu info failed\n");
534 return -ENOMEM;
535 }
536 sys_info.mem_size = real_memory_size;
537
538 return 0;
539 }
540
541 static int __init check_sdias(void)
542 {
543 int rc, act_hsa_size;
544
545 rc = sclp_sdias_blk_count();
546 if (rc < 0) {
547 ERROR_MSG("Could not determine HSA size\n");
548 return rc;
549 }
550 act_hsa_size = (rc - 1) * PAGE_SIZE;
551 if (act_hsa_size < ZFCPDUMP_HSA_SIZE) {
552 ERROR_MSG("HSA size too small: %i\n", act_hsa_size);
553 return -EINVAL;
554 }
555 return 0;
556 }
557
558 static void __init zcore_header_init(int arch, struct zcore_header *hdr)
559 {
560 if (arch == ARCH_S390X)
561 hdr->arch_id = DUMP_ARCH_S390X;
562 else
563 hdr->arch_id = DUMP_ARCH_S390;
564 hdr->mem_size = sys_info.mem_size;
565 hdr->rmem_size = sys_info.mem_size;
566 hdr->mem_end = sys_info.mem_size;
567 hdr->num_pages = sys_info.mem_size / PAGE_SIZE;
568 hdr->tod = get_clock();
569 get_cpu_id(&hdr->cpu_id);
570 }
571
572 static int __init zcore_init(void)
573 {
574 unsigned char arch;
575 int rc;
576
577 if (ipl_info.type != IPL_TYPE_FCP_DUMP)
578 return -ENODATA;
579
580 zcore_dbf = debug_register("zcore", 4, 1, 4 * sizeof(long));
581 debug_register_view(zcore_dbf, &debug_sprintf_view);
582 debug_set_level(zcore_dbf, 6);
583
584 TRACE("devno: %x\n", ipl_info.data.fcp.dev_id.devno);
585 TRACE("wwpn: %llx\n", (unsigned long long) ipl_info.data.fcp.wwpn);
586 TRACE("lun: %llx\n", (unsigned long long) ipl_info.data.fcp.lun);
587
588 rc = sclp_sdias_init();
589 if (rc)
590 goto fail;
591
592 rc = check_sdias();
593 if (rc) {
594 ERROR_MSG("Dump initialization failed\n");
595 goto fail;
596 }
597
598 rc = memcpy_hsa_kernel(&arch, __LC_AR_MODE_ID, 1);
599 if (rc) {
600 ERROR_MSG("sdial memcpy for arch id failed\n");
601 goto fail;
602 }
603
604 #ifndef __s390x__
605 if (arch == ARCH_S390X) {
606 ERROR_MSG("32 bit dumper can't dump 64 bit system!\n");
607 rc = -EINVAL;
608 goto fail;
609 }
610 #endif
611
612 rc = sys_info_init(arch);
613 if (rc) {
614 ERROR_MSG("arch init failed\n");
615 goto fail;
616 }
617
618 zcore_header_init(arch, &zcore_header);
619
620 zcore_dir = debugfs_create_dir("zcore" , NULL);
621 if (!zcore_dir) {
622 rc = -ENOMEM;
623 goto fail;
624 }
625 zcore_file = debugfs_create_file("mem", S_IRUSR, zcore_dir, NULL,
626 &zcore_fops);
627 if (!zcore_file) {
628 debugfs_remove(zcore_dir);
629 rc = -ENOMEM;
630 goto fail;
631 }
632 hsa_available = 1;
633 return 0;
634
635 fail:
636 diag308(DIAG308_REL_HSA, NULL);
637 return rc;
638 }
639
640 static void __exit zcore_exit(void)
641 {
642 debug_unregister(zcore_dbf);
643 sclp_sdias_exit();
644 diag308(DIAG308_REL_HSA, NULL);
645 }
646
647 MODULE_AUTHOR("Copyright IBM Corp. 2003,2007");
648 MODULE_DESCRIPTION("zcore module for zfcpdump support");
649 MODULE_LICENSE("GPL");
650
651 subsys_initcall(zcore_init);
652 module_exit(zcore_exit);
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