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 25 #define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x) 26 #define MSG(x...) printk( KERN_ALERT x ) 27 #define ERROR_MSG(x...) printk ( KERN_ALERT "DUMP: " x ) 28 29 #define TO_USER 0 30 #define TO_KERNEL 1 31 32 enum arch_id { 33 ARCH_S390 = 0, 34 ARCH_S390X = 1, 35 }; 36 37 /* dump system info */ 38 39 struct sys_info { 40 enum arch_id arch; 41 unsigned long sa_base; 42 u32 sa_size; 43 int cpu_map[NR_CPUS]; 44 unsigned long mem_size; 45 union save_area lc_mask; 46 }; 47 48 static struct sys_info sys_info; 49 static struct debug_info *zcore_dbf; 50 static int hsa_available; 51 static struct dentry *zcore_dir; 52 static struct dentry *zcore_file; 53 54 /* 55 * Copy memory from HSA to kernel or user memory (not reentrant): 56 * 57 * @dest: Kernel or user buffer where memory should be copied to 58 * @src: Start address within HSA where data should be copied 59 * @count: Size of buffer, which should be copied 60 * @mode: Either TO_KERNEL or TO_USER 61 */ 62 static int memcpy_hsa(void *dest, unsigned long src, size_t count, int mode) 63 { 64 int offs, blk_num; 65 static char buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); 66 67 if (count == 0) 68 return 0; 69 70 /* copy first block */ 71 offs = 0; 72 if ((src % PAGE_SIZE) != 0) { 73 blk_num = src / PAGE_SIZE + 2; 74 if (sclp_sdias_copy(buf, blk_num, 1)) { 75 TRACE("sclp_sdias_copy() failed\n"); 76 return -EIO; 77 } 78 offs = min((PAGE_SIZE - (src % PAGE_SIZE)), count); 79 if (mode == TO_USER) { 80 if (copy_to_user((__force __user void*) dest, 81 buf + (src % PAGE_SIZE), offs)) 82 return -EFAULT; 83 } else 84 memcpy(dest, buf + (src % PAGE_SIZE), offs); 85 } 86 if (offs == count) 87 goto out; 88 89 /* copy middle */ 90 for (; (offs + PAGE_SIZE) <= count; offs += PAGE_SIZE) { 91 blk_num = (src + offs) / PAGE_SIZE + 2; 92 if (sclp_sdias_copy(buf, blk_num, 1)) { 93 TRACE("sclp_sdias_copy() failed\n"); 94 return -EIO; 95 } 96 if (mode == TO_USER) { 97 if (copy_to_user((__force __user void*) dest + offs, 98 buf, PAGE_SIZE)) 99 return -EFAULT; 100 } else 101 memcpy(dest + offs, buf, PAGE_SIZE); 102 } 103 if (offs == count) 104 goto out; 105 106 /* copy last block */ 107 blk_num = (src + offs) / PAGE_SIZE + 2; 108 if (sclp_sdias_copy(buf, blk_num, 1)) { 109 TRACE("sclp_sdias_copy() failed\n"); 110 return -EIO; 111 } 112 if (mode == TO_USER) { 113 if (copy_to_user((__force __user void*) dest + offs, buf, 114 PAGE_SIZE)) 115 return -EFAULT; 116 } else 117 memcpy(dest + offs, buf, count - offs); 118 out: 119 return 0; 120 } 121 122 static int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count) 123 { 124 return memcpy_hsa((void __force *) dest, src, count, TO_USER); 125 } 126 127 static int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count) 128 { 129 return memcpy_hsa(dest, src, count, TO_KERNEL); 130 } 131 132 static int memcpy_real(void *dest, unsigned long src, size_t count) 133 { 134 unsigned long flags; 135 int rc = -EFAULT; 136 register unsigned long _dest asm("2") = (unsigned long) dest; 137 register unsigned long _len1 asm("3") = (unsigned long) count; 138 register unsigned long _src asm("4") = src; 139 register unsigned long _len2 asm("5") = (unsigned long) count; 140 141 if (count == 0) 142 return 0; 143 flags = __raw_local_irq_stnsm(0xf8); /* switch to real mode */ 144 asm volatile ( 145 "0: mvcle %1,%2,0x0\n" 146 "1: jo 0b\n" 147 " lhi %0,0x0\n" 148 "2:\n" 149 EX_TABLE(1b,2b) 150 : "+d" (rc) 151 : "d" (_dest), "d" (_src), "d" (_len1), "d" (_len2) 152 : "cc", "memory"); 153 __raw_local_irq_ssm(flags); 154 155 return rc; 156 } 157 158 static int memcpy_real_user(__user void *dest, unsigned long src, size_t count) 159 { 160 static char buf[4096]; 161 int offs = 0, size; 162 163 while (offs < count) { 164 size = min(sizeof(buf), count - offs); 165 if (memcpy_real(buf, src + offs, size)) 166 return -EFAULT; 167 if (copy_to_user(dest + offs, buf, size)) 168 return -EFAULT; 169 offs += size; 170 } 171 return 0; 172 } 173 174 #ifdef __s390x__ 175 /* 176 * Convert s390x (64 bit) cpu info to s390 (32 bit) cpu info 177 */ 178 static void __init s390x_to_s390_regs(union save_area *out, union save_area *in, 179 int cpu) 180 { 181 int i; 182 183 for (i = 0; i < 16; i++) { 184 out->s390.gp_regs[i] = in->s390x.gp_regs[i] & 0x00000000ffffffff; 185 out->s390.acc_regs[i] = in->s390x.acc_regs[i]; 186 out->s390.ctrl_regs[i] = 187 in->s390x.ctrl_regs[i] & 0x00000000ffffffff; 188 } 189 /* locore for 31 bit has only space for fpregs 0,2,4,6 */ 190 out->s390.fp_regs[0] = in->s390x.fp_regs[0]; 191 out->s390.fp_regs[1] = in->s390x.fp_regs[2]; 192 out->s390.fp_regs[2] = in->s390x.fp_regs[4]; 193 out->s390.fp_regs[3] = in->s390x.fp_regs[6]; 194 memcpy(&(out->s390.psw[0]), &(in->s390x.psw[0]), 4); 195 out->s390.psw[1] |= 0x8; /* set bit 12 */ 196 memcpy(&(out->s390.psw[4]),&(in->s390x.psw[12]), 4); 197 out->s390.psw[4] |= 0x80; /* set (31bit) addressing bit */ 198 out->s390.pref_reg = in->s390x.pref_reg; 199 out->s390.timer = in->s390x.timer; 200 out->s390.clk_cmp = in->s390x.clk_cmp; 201 } 202 203 static void __init s390x_to_s390_save_areas(void) 204 { 205 int i = 1; 206 static union save_area tmp; 207 208 while (zfcpdump_save_areas[i]) { 209 s390x_to_s390_regs(&tmp, zfcpdump_save_areas[i], i); 210 memcpy(zfcpdump_save_areas[i], &tmp, sizeof(tmp)); 211 i++; 212 } 213 } 214 215 #endif /* __s390x__ */ 216 217 static int __init init_cpu_info(enum arch_id arch) 218 { 219 union save_area *sa; 220 221 /* get info for boot cpu from lowcore, stored in the HSA */ 222 223 sa = kmalloc(sizeof(*sa), GFP_KERNEL); 224 if (!sa) { 225 ERROR_MSG("kmalloc failed: %s: %i\n",__FUNCTION__, __LINE__); 226 return -ENOMEM; 227 } 228 if (memcpy_hsa_kernel(sa, sys_info.sa_base, sys_info.sa_size) < 0) { 229 ERROR_MSG("could not copy from HSA\n"); 230 kfree(sa); 231 return -EIO; 232 } 233 zfcpdump_save_areas[0] = sa; 234 235 #ifdef __s390x__ 236 /* convert s390x regs to s390, if we are dumping an s390 Linux */ 237 238 if (arch == ARCH_S390) 239 s390x_to_s390_save_areas(); 240 #endif 241 242 return 0; 243 } 244 245 static DEFINE_MUTEX(zcore_mutex); 246 247 #define DUMP_VERSION 0x3 248 #define DUMP_MAGIC 0xa8190173618f23fdULL 249 #define DUMP_ARCH_S390X 2 250 #define DUMP_ARCH_S390 1 251 #define HEADER_SIZE 4096 252 253 /* dump header dumped according to s390 crash dump format */ 254 255 struct zcore_header { 256 u64 magic; 257 u32 version; 258 u32 header_size; 259 u32 dump_level; 260 u32 page_size; 261 u64 mem_size; 262 u64 mem_start; 263 u64 mem_end; 264 u32 num_pages; 265 u32 pad1; 266 u64 tod; 267 cpuid_t cpu_id; 268 u32 arch_id; 269 u32 build_arch; 270 char pad2[4016]; 271 } __attribute__((packed,__aligned__(16))); 272 273 static struct zcore_header zcore_header = { 274 .magic = DUMP_MAGIC, 275 .version = DUMP_VERSION, 276 .header_size = 4096, 277 .dump_level = 0, 278 .page_size = PAGE_SIZE, 279 .mem_start = 0, 280 #ifdef __s390x__ 281 .build_arch = DUMP_ARCH_S390X, 282 #else 283 .build_arch = DUMP_ARCH_S390, 284 #endif 285 }; 286 287 /* 288 * Copy lowcore info to buffer. Use map in order to copy only register parts. 289 * 290 * @buf: User buffer 291 * @sa: Pointer to save area 292 * @sa_off: Offset in save area to copy 293 * @len: Number of bytes to copy 294 */ 295 static int copy_lc(void __user *buf, void *sa, int sa_off, int len) 296 { 297 int i; 298 char *lc_mask = (char*)&sys_info.lc_mask; 299 300 for (i = 0; i < len; i++) { 301 if (!lc_mask[i + sa_off]) 302 continue; 303 if (copy_to_user(buf + i, sa + sa_off + i, 1)) 304 return -EFAULT; 305 } 306 return 0; 307 } 308 309 /* 310 * Copy lowcores info to memory, if necessary 311 * 312 * @buf: User buffer 313 * @addr: Start address of buffer in dump memory 314 * @count: Size of buffer 315 */ 316 static int zcore_add_lc(char __user *buf, unsigned long start, size_t count) 317 { 318 unsigned long end; 319 int i = 0; 320 321 if (count == 0) 322 return 0; 323 324 end = start + count; 325 while (zfcpdump_save_areas[i]) { 326 unsigned long cp_start, cp_end; /* copy range */ 327 unsigned long sa_start, sa_end; /* save area range */ 328 unsigned long prefix; 329 unsigned long sa_off, len, buf_off; 330 331 if (sys_info.arch == ARCH_S390) 332 prefix = zfcpdump_save_areas[i]->s390.pref_reg; 333 else 334 prefix = zfcpdump_save_areas[i]->s390x.pref_reg; 335 336 sa_start = prefix + sys_info.sa_base; 337 sa_end = prefix + sys_info.sa_base + sys_info.sa_size; 338 339 if ((end < sa_start) || (start > sa_end)) 340 goto next; 341 cp_start = max(start, sa_start); 342 cp_end = min(end, sa_end); 343 344 buf_off = cp_start - start; 345 sa_off = cp_start - sa_start; 346 len = cp_end - cp_start; 347 348 TRACE("copy_lc for: %lx\n", start); 349 if (copy_lc(buf + buf_off, zfcpdump_save_areas[i], sa_off, len)) 350 return -EFAULT; 351 next: 352 i++; 353 } 354 return 0; 355 } 356 357 /* 358 * Read routine for zcore character device 359 * First 4K are dump header 360 * Next 32MB are HSA Memory 361 * Rest is read from absolute Memory 362 */ 363 static ssize_t zcore_read(struct file *file, char __user *buf, size_t count, 364 loff_t *ppos) 365 { 366 unsigned long mem_start; /* Start address in memory */ 367 size_t mem_offs; /* Offset in dump memory */ 368 size_t hdr_count; /* Size of header part of output buffer */ 369 size_t size; 370 int rc; 371 372 mutex_lock(&zcore_mutex); 373 374 if (*ppos > (sys_info.mem_size + HEADER_SIZE)) { 375 rc = -EINVAL; 376 goto fail; 377 } 378 379 count = min(count, (size_t) (sys_info.mem_size + HEADER_SIZE - *ppos)); 380 381 /* Copy dump header */ 382 if (*ppos < HEADER_SIZE) { 383 size = min(count, (size_t) (HEADER_SIZE - *ppos)); 384 if (copy_to_user(buf, &zcore_header + *ppos, size)) { 385 rc = -EFAULT; 386 goto fail; 387 } 388 hdr_count = size; 389 mem_start = 0; 390 } else { 391 hdr_count = 0; 392 mem_start = *ppos - HEADER_SIZE; 393 } 394 395 mem_offs = 0; 396 397 /* Copy from HSA data */ 398 if (*ppos < (ZFCPDUMP_HSA_SIZE + HEADER_SIZE)) { 399 size = min((count - hdr_count), (size_t) (ZFCPDUMP_HSA_SIZE 400 - mem_start)); 401 rc = memcpy_hsa_user(buf + hdr_count, mem_start, size); 402 if (rc) 403 goto fail; 404 405 mem_offs += size; 406 } 407 408 /* Copy from real mem */ 409 size = count - mem_offs - hdr_count; 410 rc = memcpy_real_user(buf + hdr_count + mem_offs, mem_start + mem_offs, 411 size); 412 if (rc) 413 goto fail; 414 415 /* 416 * Since s390 dump analysis tools like lcrash or crash 417 * expect register sets in the prefix pages of the cpus, 418 * we copy them into the read buffer, if necessary. 419 * buf + hdr_count: Start of memory part of output buffer 420 * mem_start: Start memory address to copy from 421 * count - hdr_count: Size of memory area to copy 422 */ 423 if (zcore_add_lc(buf + hdr_count, mem_start, count - hdr_count)) { 424 rc = -EFAULT; 425 goto fail; 426 } 427 *ppos += count; 428 fail: 429 mutex_unlock(&zcore_mutex); 430 return (rc < 0) ? rc : count; 431 } 432 433 static int zcore_open(struct inode *inode, struct file *filp) 434 { 435 if (!hsa_available) 436 return -ENODATA; 437 else 438 return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; 439 } 440 441 static int zcore_release(struct inode *inode, struct file *filep) 442 { 443 diag308(DIAG308_REL_HSA, NULL); 444 hsa_available = 0; 445 return 0; 446 } 447 448 static loff_t zcore_lseek(struct file *file, loff_t offset, int orig) 449 { 450 loff_t rc; 451 452 mutex_lock(&zcore_mutex); 453 switch (orig) { 454 case 0: 455 file->f_pos = offset; 456 rc = file->f_pos; 457 break; 458 case 1: 459 file->f_pos += offset; 460 rc = file->f_pos; 461 break; 462 default: 463 rc = -EINVAL; 464 } 465 mutex_unlock(&zcore_mutex); 466 return rc; 467 } 468 469 static struct file_operations zcore_fops = { 470 .owner = THIS_MODULE, 471 .llseek = zcore_lseek, 472 .read = zcore_read, 473 .open = zcore_open, 474 .release = zcore_release, 475 }; 476 477 478 static void __init set_s390_lc_mask(union save_area *map) 479 { 480 memset(&map->s390.ext_save, 0xff, sizeof(map->s390.ext_save)); 481 memset(&map->s390.timer, 0xff, sizeof(map->s390.timer)); 482 memset(&map->s390.clk_cmp, 0xff, sizeof(map->s390.clk_cmp)); 483 memset(&map->s390.psw, 0xff, sizeof(map->s390.psw)); 484 memset(&map->s390.pref_reg, 0xff, sizeof(map->s390.pref_reg)); 485 memset(&map->s390.acc_regs, 0xff, sizeof(map->s390.acc_regs)); 486 memset(&map->s390.fp_regs, 0xff, sizeof(map->s390.fp_regs)); 487 memset(&map->s390.gp_regs, 0xff, sizeof(map->s390.gp_regs)); 488 memset(&map->s390.ctrl_regs, 0xff, sizeof(map->s390.ctrl_regs)); 489 } 490 491 static void __init set_s390x_lc_mask(union save_area *map) 492 { 493 memset(&map->s390x.fp_regs, 0xff, sizeof(map->s390x.fp_regs)); 494 memset(&map->s390x.gp_regs, 0xff, sizeof(map->s390x.gp_regs)); 495 memset(&map->s390x.psw, 0xff, sizeof(map->s390x.psw)); 496 memset(&map->s390x.pref_reg, 0xff, sizeof(map->s390x.pref_reg)); 497 memset(&map->s390x.fp_ctrl_reg, 0xff, sizeof(map->s390x.fp_ctrl_reg)); 498 memset(&map->s390x.tod_reg, 0xff, sizeof(map->s390x.tod_reg)); 499 memset(&map->s390x.timer, 0xff, sizeof(map->s390x.timer)); 500 memset(&map->s390x.clk_cmp, 0xff, sizeof(map->s390x.clk_cmp)); 501 memset(&map->s390x.acc_regs, 0xff, sizeof(map->s390x.acc_regs)); 502 memset(&map->s390x.ctrl_regs, 0xff, sizeof(map->s390x.ctrl_regs)); 503 } 504 505 /* 506 * Initialize dump globals for a given architecture 507 */ 508 static int __init sys_info_init(enum arch_id arch) 509 { 510 switch (arch) { 511 case ARCH_S390X: 512 MSG("DETECTED 'S390X (64 bit) OS'\n"); 513 sys_info.sa_base = SAVE_AREA_BASE_S390X; 514 sys_info.sa_size = sizeof(struct save_area_s390x); 515 set_s390x_lc_mask(&sys_info.lc_mask); 516 break; 517 case ARCH_S390: 518 MSG("DETECTED 'S390 (32 bit) OS'\n"); 519 sys_info.sa_base = SAVE_AREA_BASE_S390; 520 sys_info.sa_size = sizeof(struct save_area_s390); 521 set_s390_lc_mask(&sys_info.lc_mask); 522 break; 523 default: 524 ERROR_MSG("unknown architecture 0x%x.\n",arch); 525 return -EINVAL; 526 } 527 sys_info.arch = arch; 528 if (init_cpu_info(arch)) { 529 ERROR_MSG("get cpu info failed\n"); 530 return -ENOMEM; 531 } 532 sys_info.mem_size = real_memory_size; 533 534 return 0; 535 } 536 537 static int __init check_sdias(void) 538 { 539 int rc, act_hsa_size; 540 541 rc = sclp_sdias_blk_count(); 542 if (rc < 0) { 543 ERROR_MSG("Could not determine HSA size\n"); 544 return rc; 545 } 546 act_hsa_size = (rc - 1) * PAGE_SIZE; 547 if (act_hsa_size < ZFCPDUMP_HSA_SIZE) { 548 ERROR_MSG("HSA size too small: %i\n", act_hsa_size); 549 return -EINVAL; 550 } 551 return 0; 552 } 553 554 static void __init zcore_header_init(int arch, struct zcore_header *hdr) 555 { 556 if (arch == ARCH_S390X) 557 hdr->arch_id = DUMP_ARCH_S390X; 558 else 559 hdr->arch_id = DUMP_ARCH_S390; 560 hdr->mem_size = sys_info.mem_size; 561 hdr->mem_end = sys_info.mem_size; 562 hdr->num_pages = sys_info.mem_size / PAGE_SIZE; 563 hdr->tod = get_clock(); 564 get_cpu_id(&hdr->cpu_id); 565 } 566 567 extern int sdias_init(void); 568 569 static int __init zcore_init(void) 570 { 571 unsigned char arch; 572 int rc; 573 574 if (ipl_info.type != IPL_TYPE_FCP_DUMP) 575 return -ENODATA; 576 577 zcore_dbf = debug_register("zcore", 4, 1, 4 * sizeof(long)); 578 debug_register_view(zcore_dbf, &debug_sprintf_view); 579 debug_set_level(zcore_dbf, 6); 580 581 TRACE("devno: %x\n", ipl_info.data.fcp.dev_id.devno); 582 TRACE("wwpn: %llx\n", (unsigned long long) ipl_info.data.fcp.wwpn); 583 TRACE("lun: %llx\n", (unsigned long long) ipl_info.data.fcp.lun); 584 585 rc = sdias_init(); 586 if (rc) 587 goto fail; 588 589 rc = check_sdias(); 590 if (rc) { 591 ERROR_MSG("Dump initialization failed\n"); 592 goto fail; 593 } 594 595 rc = memcpy_hsa_kernel(&arch, __LC_AR_MODE_ID, 1); 596 if (rc) { 597 ERROR_MSG("sdial memcpy for arch id failed\n"); 598 goto fail; 599 } 600 601 #ifndef __s390x__ 602 if (arch == ARCH_S390X) { 603 ERROR_MSG("32 bit dumper can't dump 64 bit system!\n"); 604 rc = -EINVAL; 605 goto fail; 606 } 607 #endif 608 609 rc = sys_info_init(arch); 610 if (rc) { 611 ERROR_MSG("arch init failed\n"); 612 goto fail; 613 } 614 615 zcore_header_init(arch, &zcore_header); 616 617 zcore_dir = debugfs_create_dir("zcore" , NULL); 618 if (!zcore_dir) { 619 rc = -ENOMEM; 620 goto fail; 621 } 622 zcore_file = debugfs_create_file("mem", S_IRUSR, zcore_dir, NULL, 623 &zcore_fops); 624 if (!zcore_file) { 625 debugfs_remove(zcore_dir); 626 rc = -ENOMEM; 627 goto fail; 628 } 629 hsa_available = 1; 630 return 0; 631 632 fail: 633 diag308(DIAG308_REL_HSA, NULL); 634 return rc; 635 } 636 637 extern void sdias_exit(void); 638 639 static void __exit zcore_exit(void) 640 { 641 debug_unregister(zcore_dbf); 642 sdias_exit(); 643 diag308(DIAG308_REL_HSA, NULL); 644 } 645 646 MODULE_AUTHOR("Copyright IBM Corp. 2003,2007"); 647 MODULE_DESCRIPTION("zcore module for zfcpdump support"); 648 MODULE_LICENSE("GPL"); 649 650 subsys_initcall(zcore_init); 651 module_exit(zcore_exit); 652