Commit | Line | Data |
---|---|---|
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 | ||
24 | /* | |
25 | * Copy one page from "oldmem" | |
26 | * | |
27 | * For the kdump reserved memory this functions performs a swap operation: | |
28 | * - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE]. | |
29 | * - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] | |
30 | */ | |
31 | ssize_t copy_oldmem_page(unsigned long pfn, char *buf, | |
32 | size_t csize, unsigned long offset, int userbuf) | |
33 | { | |
34 | unsigned long src; | |
60a0c68d MH |
35 | |
36 | if (!csize) | |
37 | return 0; | |
38 | ||
39 | src = (pfn << PAGE_SHIFT) + offset; | |
40 | if (src < OLDMEM_SIZE) | |
41 | src += OLDMEM_BASE; | |
42 | else if (src > OLDMEM_BASE && | |
43 | src < OLDMEM_BASE + OLDMEM_SIZE) | |
44 | src -= OLDMEM_BASE; | |
45 | if (userbuf) | |
07ea815b MH |
46 | copy_to_user_real((void __force __user *) buf, (void *) src, |
47 | csize); | |
60a0c68d | 48 | else |
07ea815b MH |
49 | memcpy_real(buf, (void *) src, csize); |
50 | return csize; | |
60a0c68d MH |
51 | } |
52 | ||
53 | /* | |
54 | * Copy memory from old kernel | |
55 | */ | |
4857d4bb | 56 | int copy_from_oldmem(void *dest, void *src, size_t count) |
60a0c68d MH |
57 | { |
58 | unsigned long copied = 0; | |
59 | int rc; | |
60 | ||
61 | if ((unsigned long) src < OLDMEM_SIZE) { | |
62 | copied = min(count, OLDMEM_SIZE - (unsigned long) src); | |
63 | rc = memcpy_real(dest, src + OLDMEM_BASE, copied); | |
64 | if (rc) | |
65 | return rc; | |
66 | } | |
67 | return memcpy_real(dest + copied, src + copied, count - copied); | |
68 | } | |
69 | ||
70 | /* | |
71 | * Alloc memory and panic in case of ENOMEM | |
72 | */ | |
73 | static void *kzalloc_panic(int len) | |
74 | { | |
75 | void *rc; | |
76 | ||
77 | rc = kzalloc(len, GFP_KERNEL); | |
78 | if (!rc) | |
79 | panic("s390 kdump kzalloc (%d) failed", len); | |
80 | return rc; | |
81 | } | |
82 | ||
83 | /* | |
84 | * Get memory layout and create hole for oldmem | |
85 | */ | |
86 | static struct mem_chunk *get_memory_layout(void) | |
87 | { | |
88 | struct mem_chunk *chunk_array; | |
89 | ||
90 | chunk_array = kzalloc_panic(MEMORY_CHUNKS * sizeof(struct mem_chunk)); | |
df1bd59c | 91 | detect_memory_layout(chunk_array, 0); |
996b4a7d | 92 | create_mem_hole(chunk_array, OLDMEM_BASE, OLDMEM_SIZE); |
60a0c68d MH |
93 | return chunk_array; |
94 | } | |
95 | ||
96 | /* | |
97 | * Initialize ELF note | |
98 | */ | |
99 | static void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len, | |
100 | const char *name) | |
101 | { | |
102 | Elf64_Nhdr *note; | |
103 | u64 len; | |
104 | ||
105 | note = (Elf64_Nhdr *)buf; | |
106 | note->n_namesz = strlen(name) + 1; | |
107 | note->n_descsz = d_len; | |
108 | note->n_type = type; | |
109 | len = sizeof(Elf64_Nhdr); | |
110 | ||
111 | memcpy(buf + len, name, note->n_namesz); | |
112 | len = roundup(len + note->n_namesz, 4); | |
113 | ||
114 | memcpy(buf + len, desc, note->n_descsz); | |
115 | len = roundup(len + note->n_descsz, 4); | |
116 | ||
117 | return PTR_ADD(buf, len); | |
118 | } | |
119 | ||
120 | /* | |
121 | * Initialize prstatus note | |
122 | */ | |
123 | static void *nt_prstatus(void *ptr, struct save_area *sa) | |
124 | { | |
125 | struct elf_prstatus nt_prstatus; | |
126 | static int cpu_nr = 1; | |
127 | ||
128 | memset(&nt_prstatus, 0, sizeof(nt_prstatus)); | |
129 | memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs)); | |
130 | memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw)); | |
131 | memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs)); | |
132 | nt_prstatus.pr_pid = cpu_nr; | |
133 | cpu_nr++; | |
134 | ||
135 | return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus), | |
136 | "CORE"); | |
137 | } | |
138 | ||
139 | /* | |
140 | * Initialize fpregset (floating point) note | |
141 | */ | |
142 | static void *nt_fpregset(void *ptr, struct save_area *sa) | |
143 | { | |
144 | elf_fpregset_t nt_fpregset; | |
145 | ||
146 | memset(&nt_fpregset, 0, sizeof(nt_fpregset)); | |
147 | memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg)); | |
148 | memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs)); | |
149 | ||
150 | return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset), | |
151 | "CORE"); | |
152 | } | |
153 | ||
154 | /* | |
155 | * Initialize timer note | |
156 | */ | |
157 | static void *nt_s390_timer(void *ptr, struct save_area *sa) | |
158 | { | |
159 | return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer), | |
160 | KEXEC_CORE_NOTE_NAME); | |
161 | } | |
162 | ||
163 | /* | |
164 | * Initialize TOD clock comparator note | |
165 | */ | |
166 | static void *nt_s390_tod_cmp(void *ptr, struct save_area *sa) | |
167 | { | |
168 | return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp, | |
169 | sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME); | |
170 | } | |
171 | ||
172 | /* | |
173 | * Initialize TOD programmable register note | |
174 | */ | |
175 | static void *nt_s390_tod_preg(void *ptr, struct save_area *sa) | |
176 | { | |
177 | return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg, | |
178 | sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME); | |
179 | } | |
180 | ||
181 | /* | |
182 | * Initialize control register note | |
183 | */ | |
184 | static void *nt_s390_ctrs(void *ptr, struct save_area *sa) | |
185 | { | |
186 | return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs, | |
187 | sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME); | |
188 | } | |
189 | ||
190 | /* | |
191 | * Initialize prefix register note | |
192 | */ | |
193 | static void *nt_s390_prefix(void *ptr, struct save_area *sa) | |
194 | { | |
195 | return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg, | |
196 | sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME); | |
197 | } | |
198 | ||
199 | /* | |
200 | * Fill ELF notes for one CPU with save area registers | |
201 | */ | |
202 | void *fill_cpu_elf_notes(void *ptr, struct save_area *sa) | |
203 | { | |
204 | ptr = nt_prstatus(ptr, sa); | |
205 | ptr = nt_fpregset(ptr, sa); | |
206 | ptr = nt_s390_timer(ptr, sa); | |
207 | ptr = nt_s390_tod_cmp(ptr, sa); | |
208 | ptr = nt_s390_tod_preg(ptr, sa); | |
209 | ptr = nt_s390_ctrs(ptr, sa); | |
210 | ptr = nt_s390_prefix(ptr, sa); | |
211 | return ptr; | |
212 | } | |
213 | ||
214 | /* | |
215 | * Initialize prpsinfo note (new kernel) | |
216 | */ | |
217 | static void *nt_prpsinfo(void *ptr) | |
218 | { | |
219 | struct elf_prpsinfo prpsinfo; | |
220 | ||
221 | memset(&prpsinfo, 0, sizeof(prpsinfo)); | |
222 | prpsinfo.pr_sname = 'R'; | |
223 | strcpy(prpsinfo.pr_fname, "vmlinux"); | |
224 | return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo), | |
225 | KEXEC_CORE_NOTE_NAME); | |
226 | } | |
227 | ||
228 | /* | |
4857d4bb | 229 | * Get vmcoreinfo using lowcore->vmcore_info (new kernel) |
60a0c68d | 230 | */ |
4857d4bb | 231 | static void *get_vmcoreinfo_old(unsigned long *size) |
60a0c68d MH |
232 | { |
233 | char nt_name[11], *vmcoreinfo; | |
234 | Elf64_Nhdr note; | |
235 | void *addr; | |
236 | ||
237 | if (copy_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr))) | |
4857d4bb | 238 | return NULL; |
60a0c68d MH |
239 | memset(nt_name, 0, sizeof(nt_name)); |
240 | if (copy_from_oldmem(¬e, addr, sizeof(note))) | |
4857d4bb | 241 | return NULL; |
60a0c68d | 242 | if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1)) |
4857d4bb | 243 | return NULL; |
60a0c68d | 244 | if (strcmp(nt_name, "VMCOREINFO") != 0) |
4857d4bb MH |
245 | return NULL; |
246 | vmcoreinfo = kzalloc_panic(note.n_descsz); | |
60a0c68d | 247 | if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz)) |
4857d4bb MH |
248 | return NULL; |
249 | *size = note.n_descsz; | |
250 | return vmcoreinfo; | |
251 | } | |
252 | ||
253 | /* | |
254 | * Initialize vmcoreinfo note (new kernel) | |
255 | */ | |
256 | static void *nt_vmcoreinfo(void *ptr) | |
257 | { | |
258 | unsigned long size; | |
259 | void *vmcoreinfo; | |
260 | ||
261 | vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size); | |
262 | if (!vmcoreinfo) | |
263 | vmcoreinfo = get_vmcoreinfo_old(&size); | |
264 | if (!vmcoreinfo) | |
60a0c68d | 265 | return ptr; |
4857d4bb | 266 | return nt_init(ptr, 0, vmcoreinfo, size, "VMCOREINFO"); |
60a0c68d MH |
267 | } |
268 | ||
269 | /* | |
270 | * Initialize ELF header (new kernel) | |
271 | */ | |
272 | static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt) | |
273 | { | |
274 | memset(ehdr, 0, sizeof(*ehdr)); | |
275 | memcpy(ehdr->e_ident, ELFMAG, SELFMAG); | |
276 | ehdr->e_ident[EI_CLASS] = ELFCLASS64; | |
277 | ehdr->e_ident[EI_DATA] = ELFDATA2MSB; | |
278 | ehdr->e_ident[EI_VERSION] = EV_CURRENT; | |
279 | memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD); | |
280 | ehdr->e_type = ET_CORE; | |
281 | ehdr->e_machine = EM_S390; | |
282 | ehdr->e_version = EV_CURRENT; | |
283 | ehdr->e_phoff = sizeof(Elf64_Ehdr); | |
284 | ehdr->e_ehsize = sizeof(Elf64_Ehdr); | |
285 | ehdr->e_phentsize = sizeof(Elf64_Phdr); | |
286 | ehdr->e_phnum = mem_chunk_cnt + 1; | |
287 | return ehdr + 1; | |
288 | } | |
289 | ||
290 | /* | |
291 | * Return CPU count for ELF header (new kernel) | |
292 | */ | |
293 | static int get_cpu_cnt(void) | |
294 | { | |
295 | int i, cpus = 0; | |
296 | ||
297 | for (i = 0; zfcpdump_save_areas[i]; i++) { | |
298 | if (zfcpdump_save_areas[i]->pref_reg == 0) | |
299 | continue; | |
300 | cpus++; | |
301 | } | |
302 | return cpus; | |
303 | } | |
304 | ||
305 | /* | |
306 | * Return memory chunk count for ELF header (new kernel) | |
307 | */ | |
308 | static int get_mem_chunk_cnt(void) | |
309 | { | |
310 | struct mem_chunk *chunk_array, *mem_chunk; | |
311 | int i, cnt = 0; | |
312 | ||
313 | chunk_array = get_memory_layout(); | |
314 | for (i = 0; i < MEMORY_CHUNKS; i++) { | |
315 | mem_chunk = &chunk_array[i]; | |
316 | if (chunk_array[i].type != CHUNK_READ_WRITE && | |
317 | chunk_array[i].type != CHUNK_READ_ONLY) | |
318 | continue; | |
319 | if (mem_chunk->size == 0) | |
320 | continue; | |
321 | cnt++; | |
322 | } | |
323 | kfree(chunk_array); | |
324 | return cnt; | |
325 | } | |
326 | ||
327 | /* | |
328 | * Relocate pointer in order to allow vmcore code access the data | |
329 | */ | |
330 | static inline unsigned long relocate(unsigned long addr) | |
331 | { | |
332 | return OLDMEM_BASE + addr; | |
333 | } | |
334 | ||
335 | /* | |
336 | * Initialize ELF loads (new kernel) | |
337 | */ | |
338 | static int loads_init(Elf64_Phdr *phdr, u64 loads_offset) | |
339 | { | |
340 | struct mem_chunk *chunk_array, *mem_chunk; | |
341 | int i; | |
342 | ||
343 | chunk_array = get_memory_layout(); | |
344 | for (i = 0; i < MEMORY_CHUNKS; i++) { | |
345 | mem_chunk = &chunk_array[i]; | |
346 | if (mem_chunk->size == 0) | |
996b4a7d | 347 | continue; |
60a0c68d MH |
348 | if (chunk_array[i].type != CHUNK_READ_WRITE && |
349 | chunk_array[i].type != CHUNK_READ_ONLY) | |
350 | continue; | |
351 | else | |
352 | phdr->p_filesz = mem_chunk->size; | |
353 | phdr->p_type = PT_LOAD; | |
354 | phdr->p_offset = mem_chunk->addr; | |
355 | phdr->p_vaddr = mem_chunk->addr; | |
356 | phdr->p_paddr = mem_chunk->addr; | |
357 | phdr->p_memsz = mem_chunk->size; | |
358 | phdr->p_flags = PF_R | PF_W | PF_X; | |
359 | phdr->p_align = PAGE_SIZE; | |
360 | phdr++; | |
361 | } | |
362 | kfree(chunk_array); | |
363 | return i; | |
364 | } | |
365 | ||
366 | /* | |
367 | * Initialize notes (new kernel) | |
368 | */ | |
369 | static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset) | |
370 | { | |
371 | struct save_area *sa; | |
372 | void *ptr_start = ptr; | |
373 | int i; | |
374 | ||
375 | ptr = nt_prpsinfo(ptr); | |
376 | ||
377 | for (i = 0; zfcpdump_save_areas[i]; i++) { | |
378 | sa = zfcpdump_save_areas[i]; | |
379 | if (sa->pref_reg == 0) | |
380 | continue; | |
381 | ptr = fill_cpu_elf_notes(ptr, sa); | |
382 | } | |
383 | ptr = nt_vmcoreinfo(ptr); | |
384 | memset(phdr, 0, sizeof(*phdr)); | |
385 | phdr->p_type = PT_NOTE; | |
386 | phdr->p_offset = relocate(notes_offset); | |
387 | phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start); | |
388 | phdr->p_memsz = phdr->p_filesz; | |
389 | return ptr; | |
390 | } | |
391 | ||
392 | /* | |
393 | * Create ELF core header (new kernel) | |
394 | */ | |
395 | static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz) | |
396 | { | |
397 | Elf64_Phdr *phdr_notes, *phdr_loads; | |
398 | int mem_chunk_cnt; | |
399 | void *ptr, *hdr; | |
400 | u32 alloc_size; | |
401 | u64 hdr_off; | |
402 | ||
403 | mem_chunk_cnt = get_mem_chunk_cnt(); | |
404 | ||
405 | alloc_size = 0x1000 + get_cpu_cnt() * 0x300 + | |
406 | mem_chunk_cnt * sizeof(Elf64_Phdr); | |
407 | hdr = kzalloc_panic(alloc_size); | |
408 | /* Init elf header */ | |
409 | ptr = ehdr_init(hdr, mem_chunk_cnt); | |
410 | /* Init program headers */ | |
411 | phdr_notes = ptr; | |
412 | ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr)); | |
413 | phdr_loads = ptr; | |
414 | ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt); | |
415 | /* Init notes */ | |
416 | hdr_off = PTR_DIFF(ptr, hdr); | |
417 | ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off); | |
418 | /* Init loads */ | |
419 | hdr_off = PTR_DIFF(ptr, hdr); | |
420 | loads_init(phdr_loads, ((unsigned long) hdr) + hdr_off); | |
421 | *elfcorebuf_sz = hdr_off; | |
422 | *elfcorebuf = (void *) relocate((unsigned long) hdr); | |
423 | BUG_ON(*elfcorebuf_sz > alloc_size); | |
424 | } | |
425 | ||
426 | /* | |
427 | * Create kdump ELF core header in new kernel, if it has not been passed via | |
428 | * the "elfcorehdr" kernel parameter | |
429 | */ | |
430 | static int setup_kdump_elfcorehdr(void) | |
431 | { | |
432 | size_t elfcorebuf_sz; | |
433 | char *elfcorebuf; | |
434 | ||
435 | if (!OLDMEM_BASE || is_kdump_kernel()) | |
436 | return -EINVAL; | |
437 | s390_elf_corehdr_create(&elfcorebuf, &elfcorebuf_sz); | |
438 | elfcorehdr_addr = (unsigned long long) elfcorebuf; | |
439 | elfcorehdr_size = elfcorebuf_sz; | |
440 | return 0; | |
441 | } | |
442 | ||
443 | subsys_initcall(setup_kdump_elfcorehdr); |