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); 653