Commit | Line | Data |
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60a0c68d MH |
1 | /* |
2 | * S390 kdump implementation | |
3 | * | |
4 | * Copyright IBM Corp. 2011 | |
5 | * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com> | |
6 | */ | |
7 | ||
8 | #include <linux/crash_dump.h> | |
9 | #include <asm/lowcore.h> | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/gfp.h> | |
13 | #include <linux/slab.h> | |
60a0c68d MH |
14 | #include <linux/bootmem.h> |
15 | #include <linux/elf.h> | |
4857d4bb | 16 | #include <asm/os_info.h> |
6b563d8c HC |
17 | #include <asm/elf.h> |
18 | #include <asm/ipl.h> | |
60a0c68d MH |
19 | |
20 | #define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y))) | |
21 | #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y))) | |
22 | #define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y)))) | |
23 | ||
191a2fa0 MH |
24 | |
25 | /* | |
26 | * Return physical address for virtual address | |
27 | */ | |
28 | static inline void *load_real_addr(void *addr) | |
29 | { | |
30 | unsigned long real_addr; | |
31 | ||
32 | asm volatile( | |
33 | " lra %0,0(%1)\n" | |
34 | " jz 0f\n" | |
35 | " la %0,0\n" | |
36 | "0:" | |
37 | : "=a" (real_addr) : "a" (addr) : "cc"); | |
38 | return (void *)real_addr; | |
39 | } | |
40 | ||
41 | /* | |
42 | * Copy up to one page to vmalloc or real memory | |
43 | */ | |
44 | static ssize_t copy_page_real(void *buf, void *src, size_t csize) | |
45 | { | |
46 | size_t size; | |
47 | ||
48 | if (is_vmalloc_addr(buf)) { | |
49 | BUG_ON(csize >= PAGE_SIZE); | |
50 | /* If buf is not page aligned, copy first part */ | |
51 | size = min(roundup(__pa(buf), PAGE_SIZE) - __pa(buf), csize); | |
52 | if (size) { | |
53 | if (memcpy_real(load_real_addr(buf), src, size)) | |
54 | return -EFAULT; | |
55 | buf += size; | |
56 | src += size; | |
57 | } | |
58 | /* Copy second part */ | |
59 | size = csize - size; | |
60 | return (size) ? memcpy_real(load_real_addr(buf), src, size) : 0; | |
61 | } else { | |
62 | return memcpy_real(buf, src, csize); | |
63 | } | |
64 | } | |
65 | ||
60a0c68d MH |
66 | /* |
67 | * Copy one page from "oldmem" | |
68 | * | |
69 | * For the kdump reserved memory this functions performs a swap operation: | |
70 | * - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE]. | |
71 | * - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] | |
72 | */ | |
73 | ssize_t copy_oldmem_page(unsigned long pfn, char *buf, | |
74 | size_t csize, unsigned long offset, int userbuf) | |
75 | { | |
76 | unsigned long src; | |
191a2fa0 | 77 | int rc; |
60a0c68d MH |
78 | |
79 | if (!csize) | |
80 | return 0; | |
81 | ||
82 | src = (pfn << PAGE_SHIFT) + offset; | |
83 | if (src < OLDMEM_SIZE) | |
84 | src += OLDMEM_BASE; | |
85 | else if (src > OLDMEM_BASE && | |
86 | src < OLDMEM_BASE + OLDMEM_SIZE) | |
87 | src -= OLDMEM_BASE; | |
88 | if (userbuf) | |
191a2fa0 MH |
89 | rc = copy_to_user_real((void __force __user *) buf, |
90 | (void *) src, csize); | |
60a0c68d | 91 | else |
191a2fa0 MH |
92 | rc = copy_page_real(buf, (void *) src, csize); |
93 | return (rc == 0) ? csize : rc; | |
60a0c68d MH |
94 | } |
95 | ||
96 | /* | |
97 | * Copy memory from old kernel | |
98 | */ | |
4857d4bb | 99 | int copy_from_oldmem(void *dest, void *src, size_t count) |
60a0c68d MH |
100 | { |
101 | unsigned long copied = 0; | |
102 | int rc; | |
103 | ||
104 | if ((unsigned long) src < OLDMEM_SIZE) { | |
105 | copied = min(count, OLDMEM_SIZE - (unsigned long) src); | |
106 | rc = memcpy_real(dest, src + OLDMEM_BASE, copied); | |
107 | if (rc) | |
108 | return rc; | |
109 | } | |
110 | return memcpy_real(dest + copied, src + copied, count - copied); | |
111 | } | |
112 | ||
113 | /* | |
114 | * Alloc memory and panic in case of ENOMEM | |
115 | */ | |
116 | static void *kzalloc_panic(int len) | |
117 | { | |
118 | void *rc; | |
119 | ||
120 | rc = kzalloc(len, GFP_KERNEL); | |
121 | if (!rc) | |
122 | panic("s390 kdump kzalloc (%d) failed", len); | |
123 | return rc; | |
124 | } | |
125 | ||
126 | /* | |
127 | * Get memory layout and create hole for oldmem | |
128 | */ | |
129 | static struct mem_chunk *get_memory_layout(void) | |
130 | { | |
131 | struct mem_chunk *chunk_array; | |
132 | ||
133 | chunk_array = kzalloc_panic(MEMORY_CHUNKS * sizeof(struct mem_chunk)); | |
df1bd59c | 134 | detect_memory_layout(chunk_array, 0); |
996b4a7d | 135 | create_mem_hole(chunk_array, OLDMEM_BASE, OLDMEM_SIZE); |
60a0c68d MH |
136 | return chunk_array; |
137 | } | |
138 | ||
139 | /* | |
140 | * Initialize ELF note | |
141 | */ | |
142 | static void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len, | |
143 | const char *name) | |
144 | { | |
145 | Elf64_Nhdr *note; | |
146 | u64 len; | |
147 | ||
148 | note = (Elf64_Nhdr *)buf; | |
149 | note->n_namesz = strlen(name) + 1; | |
150 | note->n_descsz = d_len; | |
151 | note->n_type = type; | |
152 | len = sizeof(Elf64_Nhdr); | |
153 | ||
154 | memcpy(buf + len, name, note->n_namesz); | |
155 | len = roundup(len + note->n_namesz, 4); | |
156 | ||
157 | memcpy(buf + len, desc, note->n_descsz); | |
158 | len = roundup(len + note->n_descsz, 4); | |
159 | ||
160 | return PTR_ADD(buf, len); | |
161 | } | |
162 | ||
163 | /* | |
164 | * Initialize prstatus note | |
165 | */ | |
166 | static void *nt_prstatus(void *ptr, struct save_area *sa) | |
167 | { | |
168 | struct elf_prstatus nt_prstatus; | |
169 | static int cpu_nr = 1; | |
170 | ||
171 | memset(&nt_prstatus, 0, sizeof(nt_prstatus)); | |
172 | memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs)); | |
173 | memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw)); | |
174 | memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs)); | |
175 | nt_prstatus.pr_pid = cpu_nr; | |
176 | cpu_nr++; | |
177 | ||
178 | return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus), | |
179 | "CORE"); | |
180 | } | |
181 | ||
182 | /* | |
183 | * Initialize fpregset (floating point) note | |
184 | */ | |
185 | static void *nt_fpregset(void *ptr, struct save_area *sa) | |
186 | { | |
187 | elf_fpregset_t nt_fpregset; | |
188 | ||
189 | memset(&nt_fpregset, 0, sizeof(nt_fpregset)); | |
190 | memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg)); | |
191 | memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs)); | |
192 | ||
193 | return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset), | |
194 | "CORE"); | |
195 | } | |
196 | ||
197 | /* | |
198 | * Initialize timer note | |
199 | */ | |
200 | static void *nt_s390_timer(void *ptr, struct save_area *sa) | |
201 | { | |
202 | return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer), | |
203 | KEXEC_CORE_NOTE_NAME); | |
204 | } | |
205 | ||
206 | /* | |
207 | * Initialize TOD clock comparator note | |
208 | */ | |
209 | static void *nt_s390_tod_cmp(void *ptr, struct save_area *sa) | |
210 | { | |
211 | return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp, | |
212 | sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME); | |
213 | } | |
214 | ||
215 | /* | |
216 | * Initialize TOD programmable register note | |
217 | */ | |
218 | static void *nt_s390_tod_preg(void *ptr, struct save_area *sa) | |
219 | { | |
220 | return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg, | |
221 | sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME); | |
222 | } | |
223 | ||
224 | /* | |
225 | * Initialize control register note | |
226 | */ | |
227 | static void *nt_s390_ctrs(void *ptr, struct save_area *sa) | |
228 | { | |
229 | return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs, | |
230 | sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME); | |
231 | } | |
232 | ||
233 | /* | |
234 | * Initialize prefix register note | |
235 | */ | |
236 | static void *nt_s390_prefix(void *ptr, struct save_area *sa) | |
237 | { | |
238 | return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg, | |
239 | sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME); | |
240 | } | |
241 | ||
242 | /* | |
243 | * Fill ELF notes for one CPU with save area registers | |
244 | */ | |
245 | void *fill_cpu_elf_notes(void *ptr, struct save_area *sa) | |
246 | { | |
247 | ptr = nt_prstatus(ptr, sa); | |
248 | ptr = nt_fpregset(ptr, sa); | |
249 | ptr = nt_s390_timer(ptr, sa); | |
250 | ptr = nt_s390_tod_cmp(ptr, sa); | |
251 | ptr = nt_s390_tod_preg(ptr, sa); | |
252 | ptr = nt_s390_ctrs(ptr, sa); | |
253 | ptr = nt_s390_prefix(ptr, sa); | |
254 | return ptr; | |
255 | } | |
256 | ||
257 | /* | |
258 | * Initialize prpsinfo note (new kernel) | |
259 | */ | |
260 | static void *nt_prpsinfo(void *ptr) | |
261 | { | |
262 | struct elf_prpsinfo prpsinfo; | |
263 | ||
264 | memset(&prpsinfo, 0, sizeof(prpsinfo)); | |
265 | prpsinfo.pr_sname = 'R'; | |
266 | strcpy(prpsinfo.pr_fname, "vmlinux"); | |
267 | return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo), | |
268 | KEXEC_CORE_NOTE_NAME); | |
269 | } | |
270 | ||
271 | /* | |
4857d4bb | 272 | * Get vmcoreinfo using lowcore->vmcore_info (new kernel) |
60a0c68d | 273 | */ |
4857d4bb | 274 | static void *get_vmcoreinfo_old(unsigned long *size) |
60a0c68d MH |
275 | { |
276 | char nt_name[11], *vmcoreinfo; | |
277 | Elf64_Nhdr note; | |
278 | void *addr; | |
279 | ||
280 | if (copy_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr))) | |
4857d4bb | 281 | return NULL; |
60a0c68d MH |
282 | memset(nt_name, 0, sizeof(nt_name)); |
283 | if (copy_from_oldmem(¬e, addr, sizeof(note))) | |
4857d4bb | 284 | return NULL; |
60a0c68d | 285 | if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1)) |
4857d4bb | 286 | return NULL; |
60a0c68d | 287 | if (strcmp(nt_name, "VMCOREINFO") != 0) |
4857d4bb MH |
288 | return NULL; |
289 | vmcoreinfo = kzalloc_panic(note.n_descsz); | |
60a0c68d | 290 | if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz)) |
4857d4bb MH |
291 | return NULL; |
292 | *size = note.n_descsz; | |
293 | return vmcoreinfo; | |
294 | } | |
295 | ||
296 | /* | |
297 | * Initialize vmcoreinfo note (new kernel) | |
298 | */ | |
299 | static void *nt_vmcoreinfo(void *ptr) | |
300 | { | |
301 | unsigned long size; | |
302 | void *vmcoreinfo; | |
303 | ||
304 | vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size); | |
305 | if (!vmcoreinfo) | |
306 | vmcoreinfo = get_vmcoreinfo_old(&size); | |
307 | if (!vmcoreinfo) | |
60a0c68d | 308 | return ptr; |
4857d4bb | 309 | return nt_init(ptr, 0, vmcoreinfo, size, "VMCOREINFO"); |
60a0c68d MH |
310 | } |
311 | ||
312 | /* | |
313 | * Initialize ELF header (new kernel) | |
314 | */ | |
315 | static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt) | |
316 | { | |
317 | memset(ehdr, 0, sizeof(*ehdr)); | |
318 | memcpy(ehdr->e_ident, ELFMAG, SELFMAG); | |
319 | ehdr->e_ident[EI_CLASS] = ELFCLASS64; | |
320 | ehdr->e_ident[EI_DATA] = ELFDATA2MSB; | |
321 | ehdr->e_ident[EI_VERSION] = EV_CURRENT; | |
322 | memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD); | |
323 | ehdr->e_type = ET_CORE; | |
324 | ehdr->e_machine = EM_S390; | |
325 | ehdr->e_version = EV_CURRENT; | |
326 | ehdr->e_phoff = sizeof(Elf64_Ehdr); | |
327 | ehdr->e_ehsize = sizeof(Elf64_Ehdr); | |
328 | ehdr->e_phentsize = sizeof(Elf64_Phdr); | |
329 | ehdr->e_phnum = mem_chunk_cnt + 1; | |
330 | return ehdr + 1; | |
331 | } | |
332 | ||
333 | /* | |
334 | * Return CPU count for ELF header (new kernel) | |
335 | */ | |
336 | static int get_cpu_cnt(void) | |
337 | { | |
338 | int i, cpus = 0; | |
339 | ||
340 | for (i = 0; zfcpdump_save_areas[i]; i++) { | |
341 | if (zfcpdump_save_areas[i]->pref_reg == 0) | |
342 | continue; | |
343 | cpus++; | |
344 | } | |
345 | return cpus; | |
346 | } | |
347 | ||
348 | /* | |
349 | * Return memory chunk count for ELF header (new kernel) | |
350 | */ | |
351 | static int get_mem_chunk_cnt(void) | |
352 | { | |
353 | struct mem_chunk *chunk_array, *mem_chunk; | |
354 | int i, cnt = 0; | |
355 | ||
356 | chunk_array = get_memory_layout(); | |
357 | for (i = 0; i < MEMORY_CHUNKS; i++) { | |
358 | mem_chunk = &chunk_array[i]; | |
359 | if (chunk_array[i].type != CHUNK_READ_WRITE && | |
360 | chunk_array[i].type != CHUNK_READ_ONLY) | |
361 | continue; | |
362 | if (mem_chunk->size == 0) | |
363 | continue; | |
364 | cnt++; | |
365 | } | |
366 | kfree(chunk_array); | |
367 | return cnt; | |
368 | } | |
369 | ||
370 | /* | |
371 | * Relocate pointer in order to allow vmcore code access the data | |
372 | */ | |
373 | static inline unsigned long relocate(unsigned long addr) | |
374 | { | |
375 | return OLDMEM_BASE + addr; | |
376 | } | |
377 | ||
378 | /* | |
379 | * Initialize ELF loads (new kernel) | |
380 | */ | |
381 | static int loads_init(Elf64_Phdr *phdr, u64 loads_offset) | |
382 | { | |
383 | struct mem_chunk *chunk_array, *mem_chunk; | |
384 | int i; | |
385 | ||
386 | chunk_array = get_memory_layout(); | |
387 | for (i = 0; i < MEMORY_CHUNKS; i++) { | |
388 | mem_chunk = &chunk_array[i]; | |
389 | if (mem_chunk->size == 0) | |
996b4a7d | 390 | continue; |
60a0c68d MH |
391 | if (chunk_array[i].type != CHUNK_READ_WRITE && |
392 | chunk_array[i].type != CHUNK_READ_ONLY) | |
393 | continue; | |
394 | else | |
395 | phdr->p_filesz = mem_chunk->size; | |
396 | phdr->p_type = PT_LOAD; | |
397 | phdr->p_offset = mem_chunk->addr; | |
398 | phdr->p_vaddr = mem_chunk->addr; | |
399 | phdr->p_paddr = mem_chunk->addr; | |
400 | phdr->p_memsz = mem_chunk->size; | |
401 | phdr->p_flags = PF_R | PF_W | PF_X; | |
402 | phdr->p_align = PAGE_SIZE; | |
403 | phdr++; | |
404 | } | |
405 | kfree(chunk_array); | |
406 | return i; | |
407 | } | |
408 | ||
409 | /* | |
410 | * Initialize notes (new kernel) | |
411 | */ | |
412 | static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset) | |
413 | { | |
414 | struct save_area *sa; | |
415 | void *ptr_start = ptr; | |
416 | int i; | |
417 | ||
418 | ptr = nt_prpsinfo(ptr); | |
419 | ||
420 | for (i = 0; zfcpdump_save_areas[i]; i++) { | |
421 | sa = zfcpdump_save_areas[i]; | |
422 | if (sa->pref_reg == 0) | |
423 | continue; | |
424 | ptr = fill_cpu_elf_notes(ptr, sa); | |
425 | } | |
426 | ptr = nt_vmcoreinfo(ptr); | |
427 | memset(phdr, 0, sizeof(*phdr)); | |
428 | phdr->p_type = PT_NOTE; | |
429 | phdr->p_offset = relocate(notes_offset); | |
430 | phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start); | |
431 | phdr->p_memsz = phdr->p_filesz; | |
432 | return ptr; | |
433 | } | |
434 | ||
435 | /* | |
436 | * Create ELF core header (new kernel) | |
437 | */ | |
438 | static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz) | |
439 | { | |
440 | Elf64_Phdr *phdr_notes, *phdr_loads; | |
441 | int mem_chunk_cnt; | |
442 | void *ptr, *hdr; | |
443 | u32 alloc_size; | |
444 | u64 hdr_off; | |
445 | ||
446 | mem_chunk_cnt = get_mem_chunk_cnt(); | |
447 | ||
448 | alloc_size = 0x1000 + get_cpu_cnt() * 0x300 + | |
449 | mem_chunk_cnt * sizeof(Elf64_Phdr); | |
450 | hdr = kzalloc_panic(alloc_size); | |
451 | /* Init elf header */ | |
452 | ptr = ehdr_init(hdr, mem_chunk_cnt); | |
453 | /* Init program headers */ | |
454 | phdr_notes = ptr; | |
455 | ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr)); | |
456 | phdr_loads = ptr; | |
457 | ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt); | |
458 | /* Init notes */ | |
459 | hdr_off = PTR_DIFF(ptr, hdr); | |
460 | ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off); | |
461 | /* Init loads */ | |
462 | hdr_off = PTR_DIFF(ptr, hdr); | |
463 | loads_init(phdr_loads, ((unsigned long) hdr) + hdr_off); | |
464 | *elfcorebuf_sz = hdr_off; | |
465 | *elfcorebuf = (void *) relocate((unsigned long) hdr); | |
466 | BUG_ON(*elfcorebuf_sz > alloc_size); | |
467 | } | |
468 | ||
469 | /* | |
470 | * Create kdump ELF core header in new kernel, if it has not been passed via | |
471 | * the "elfcorehdr" kernel parameter | |
472 | */ | |
473 | static int setup_kdump_elfcorehdr(void) | |
474 | { | |
475 | size_t elfcorebuf_sz; | |
476 | char *elfcorebuf; | |
477 | ||
478 | if (!OLDMEM_BASE || is_kdump_kernel()) | |
479 | return -EINVAL; | |
480 | s390_elf_corehdr_create(&elfcorebuf, &elfcorebuf_sz); | |
481 | elfcorehdr_addr = (unsigned long long) elfcorebuf; | |
482 | elfcorehdr_size = elfcorebuf_sz; | |
483 | return 0; | |
484 | } | |
485 | ||
486 | subsys_initcall(setup_kdump_elfcorehdr); |