2 * S390 kdump implementation
4 * Copyright IBM Corp. 2011
5 * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
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>
14 #include <linux/bootmem.h>
15 #include <linux/elf.h>
16 #include <linux/memblock.h>
17 #include <asm/os_info.h>
22 #define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
23 #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
24 #define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
26 static struct memblock_region oldmem_region;
28 static struct memblock_type oldmem_type = {
32 .regions = &oldmem_region,
35 #define for_each_dump_mem_range(i, nid, p_start, p_end, p_nid) \
36 for (i = 0, __next_mem_range(&i, nid, &memblock.physmem, \
37 &oldmem_type, p_start, \
39 i != (u64)ULLONG_MAX; \
40 __next_mem_range(&i, nid, &memblock.physmem, \
42 p_start, p_end, p_nid))
44 struct dump_save_areas dump_save_areas;
47 * Allocate and add a save area for a CPU
49 struct save_area *dump_save_area_create(int cpu)
51 struct save_area **save_areas, *save_area;
53 save_area = kmalloc(sizeof(*save_area), GFP_KERNEL);
56 if (cpu + 1 > dump_save_areas.count) {
57 dump_save_areas.count = cpu + 1;
58 save_areas = krealloc(dump_save_areas.areas,
59 dump_save_areas.count * sizeof(void *),
60 GFP_KERNEL | __GFP_ZERO);
65 dump_save_areas.areas = save_areas;
67 dump_save_areas.areas[cpu] = save_area;
72 * Return physical address for virtual address
74 static inline void *load_real_addr(void *addr)
76 unsigned long real_addr;
83 : "=a" (real_addr) : "a" (addr) : "cc");
84 return (void *)real_addr;
88 * Copy real to virtual or real memory
90 static int copy_from_realmem(void *dest, void *src, size_t count)
96 if (!is_vmalloc_or_module_addr(dest))
97 return memcpy_real(dest, src, count);
99 size = min(count, PAGE_SIZE - (__pa(dest) & ~PAGE_MASK));
100 if (memcpy_real(load_real_addr(dest), src, size))
110 * Pointer to ELF header in new kernel
112 static void *elfcorehdr_newmem;
115 * Copy one page from zfcpdump "oldmem"
117 * For pages below HSA size memory from the HSA is copied. Otherwise
118 * real memory copy is used.
120 static ssize_t copy_oldmem_page_zfcpdump(char *buf, size_t csize,
121 unsigned long src, int userbuf)
125 if (src < sclp_get_hsa_size()) {
126 rc = memcpy_hsa(buf, src, csize, userbuf);
129 rc = copy_to_user_real((void __force __user *) buf,
130 (void *) src, csize);
132 rc = memcpy_real(buf, (void *) src, csize);
134 return rc ? rc : csize;
138 * Copy one page from kdump "oldmem"
140 * For the kdump reserved memory this functions performs a swap operation:
141 * - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE].
142 * - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
144 static ssize_t copy_oldmem_page_kdump(char *buf, size_t csize,
145 unsigned long src, int userbuf)
150 if (src < OLDMEM_SIZE)
152 else if (src > OLDMEM_BASE &&
153 src < OLDMEM_BASE + OLDMEM_SIZE)
156 rc = copy_to_user_real((void __force __user *) buf,
157 (void *) src, csize);
159 rc = copy_from_realmem(buf, (void *) src, csize);
160 return (rc == 0) ? rc : csize;
164 * Copy one page from "oldmem"
166 ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
167 unsigned long offset, int userbuf)
173 src = (pfn << PAGE_SHIFT) + offset;
175 return copy_oldmem_page_kdump(buf, csize, src, userbuf);
177 return copy_oldmem_page_zfcpdump(buf, csize, src, userbuf);
181 * Remap "oldmem" for kdump
183 * For the kdump reserved memory this functions performs a swap operation:
184 * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
186 static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
187 unsigned long from, unsigned long pfn,
188 unsigned long size, pgprot_t prot)
190 unsigned long size_old;
193 if (pfn < OLDMEM_SIZE >> PAGE_SHIFT) {
194 size_old = min(size, OLDMEM_SIZE - (pfn << PAGE_SHIFT));
195 rc = remap_pfn_range(vma, from,
196 pfn + (OLDMEM_BASE >> PAGE_SHIFT),
198 if (rc || size == size_old)
202 pfn += size_old >> PAGE_SHIFT;
204 return remap_pfn_range(vma, from, pfn, size, prot);
208 * Remap "oldmem" for zfcpdump
210 * We only map available memory above HSA size. Memory below HSA size
211 * is read on demand using the copy_oldmem_page() function.
213 static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
216 unsigned long size, pgprot_t prot)
218 unsigned long hsa_end = sclp_get_hsa_size();
219 unsigned long size_hsa;
221 if (pfn < hsa_end >> PAGE_SHIFT) {
222 size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT));
223 if (size == size_hsa)
227 pfn += size_hsa >> PAGE_SHIFT;
229 return remap_pfn_range(vma, from, pfn, size, prot);
233 * Remap "oldmem" for kdump or zfcpdump
235 int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
236 unsigned long pfn, unsigned long size, pgprot_t prot)
239 return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
241 return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
246 * Copy memory from old kernel
248 int copy_from_oldmem(void *dest, void *src, size_t count)
250 unsigned long copied = 0;
254 if ((unsigned long) src < OLDMEM_SIZE) {
255 copied = min(count, OLDMEM_SIZE - (unsigned long) src);
256 rc = copy_from_realmem(dest, src + OLDMEM_BASE, copied);
261 unsigned long hsa_end = sclp_get_hsa_size();
262 if ((unsigned long) src < hsa_end) {
263 copied = min(count, hsa_end - (unsigned long) src);
264 rc = memcpy_hsa(dest, (unsigned long) src, copied, 0);
269 return copy_from_realmem(dest + copied, src + copied, count - copied);
273 * Alloc memory and panic in case of ENOMEM
275 static void *kzalloc_panic(int len)
279 rc = kzalloc(len, GFP_KERNEL);
281 panic("s390 kdump kzalloc (%d) failed", len);
286 * Initialize ELF note
288 static void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len,
294 note = (Elf64_Nhdr *)buf;
295 note->n_namesz = strlen(name) + 1;
296 note->n_descsz = d_len;
298 len = sizeof(Elf64_Nhdr);
300 memcpy(buf + len, name, note->n_namesz);
301 len = roundup(len + note->n_namesz, 4);
303 memcpy(buf + len, desc, note->n_descsz);
304 len = roundup(len + note->n_descsz, 4);
306 return PTR_ADD(buf, len);
310 * Initialize prstatus note
312 static void *nt_prstatus(void *ptr, struct save_area *sa)
314 struct elf_prstatus nt_prstatus;
315 static int cpu_nr = 1;
317 memset(&nt_prstatus, 0, sizeof(nt_prstatus));
318 memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs));
319 memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
320 memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs));
321 nt_prstatus.pr_pid = cpu_nr;
324 return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus),
329 * Initialize fpregset (floating point) note
331 static void *nt_fpregset(void *ptr, struct save_area *sa)
333 elf_fpregset_t nt_fpregset;
335 memset(&nt_fpregset, 0, sizeof(nt_fpregset));
336 memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg));
337 memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs));
339 return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset),
344 * Initialize timer note
346 static void *nt_s390_timer(void *ptr, struct save_area *sa)
348 return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer),
349 KEXEC_CORE_NOTE_NAME);
353 * Initialize TOD clock comparator note
355 static void *nt_s390_tod_cmp(void *ptr, struct save_area *sa)
357 return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp,
358 sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME);
362 * Initialize TOD programmable register note
364 static void *nt_s390_tod_preg(void *ptr, struct save_area *sa)
366 return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg,
367 sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME);
371 * Initialize control register note
373 static void *nt_s390_ctrs(void *ptr, struct save_area *sa)
375 return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs,
376 sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME);
380 * Initialize prefix register note
382 static void *nt_s390_prefix(void *ptr, struct save_area *sa)
384 return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg,
385 sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME);
389 * Fill ELF notes for one CPU with save area registers
391 void *fill_cpu_elf_notes(void *ptr, struct save_area *sa)
393 ptr = nt_prstatus(ptr, sa);
394 ptr = nt_fpregset(ptr, sa);
395 ptr = nt_s390_timer(ptr, sa);
396 ptr = nt_s390_tod_cmp(ptr, sa);
397 ptr = nt_s390_tod_preg(ptr, sa);
398 ptr = nt_s390_ctrs(ptr, sa);
399 ptr = nt_s390_prefix(ptr, sa);
404 * Initialize prpsinfo note (new kernel)
406 static void *nt_prpsinfo(void *ptr)
408 struct elf_prpsinfo prpsinfo;
410 memset(&prpsinfo, 0, sizeof(prpsinfo));
411 prpsinfo.pr_sname = 'R';
412 strcpy(prpsinfo.pr_fname, "vmlinux");
413 return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo),
414 KEXEC_CORE_NOTE_NAME);
418 * Get vmcoreinfo using lowcore->vmcore_info (new kernel)
420 static void *get_vmcoreinfo_old(unsigned long *size)
422 char nt_name[11], *vmcoreinfo;
426 if (copy_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
428 memset(nt_name, 0, sizeof(nt_name));
429 if (copy_from_oldmem(¬e, addr, sizeof(note)))
431 if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1))
433 if (strcmp(nt_name, "VMCOREINFO") != 0)
435 vmcoreinfo = kzalloc_panic(note.n_descsz);
436 if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz))
438 *size = note.n_descsz;
443 * Initialize vmcoreinfo note (new kernel)
445 static void *nt_vmcoreinfo(void *ptr)
450 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
452 vmcoreinfo = get_vmcoreinfo_old(&size);
455 return nt_init(ptr, 0, vmcoreinfo, size, "VMCOREINFO");
459 * Initialize ELF header (new kernel)
461 static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt)
463 memset(ehdr, 0, sizeof(*ehdr));
464 memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
465 ehdr->e_ident[EI_CLASS] = ELFCLASS64;
466 ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
467 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
468 memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
469 ehdr->e_type = ET_CORE;
470 ehdr->e_machine = EM_S390;
471 ehdr->e_version = EV_CURRENT;
472 ehdr->e_phoff = sizeof(Elf64_Ehdr);
473 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
474 ehdr->e_phentsize = sizeof(Elf64_Phdr);
475 ehdr->e_phnum = mem_chunk_cnt + 1;
480 * Return CPU count for ELF header (new kernel)
482 static int get_cpu_cnt(void)
486 for (i = 0; i < dump_save_areas.count; i++) {
487 if (dump_save_areas.areas[i]->pref_reg == 0)
495 * Return memory chunk count for ELF header (new kernel)
497 static int get_mem_chunk_cnt(void)
502 for_each_dump_mem_range(idx, NUMA_NO_NODE, NULL, NULL, NULL)
508 * Initialize ELF loads (new kernel)
510 static void loads_init(Elf64_Phdr *phdr, u64 loads_offset)
512 phys_addr_t start, end;
515 for_each_dump_mem_range(idx, NUMA_NO_NODE, &start, &end, NULL) {
516 phdr->p_filesz = end - start;
517 phdr->p_type = PT_LOAD;
518 phdr->p_offset = start;
519 phdr->p_vaddr = start;
520 phdr->p_paddr = start;
521 phdr->p_memsz = end - start;
522 phdr->p_flags = PF_R | PF_W | PF_X;
523 phdr->p_align = PAGE_SIZE;
529 * Initialize notes (new kernel)
531 static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
533 struct save_area *sa;
534 void *ptr_start = ptr;
537 ptr = nt_prpsinfo(ptr);
539 for (i = 0; i < dump_save_areas.count; i++) {
540 sa = dump_save_areas.areas[i];
541 if (sa->pref_reg == 0)
543 ptr = fill_cpu_elf_notes(ptr, sa);
545 ptr = nt_vmcoreinfo(ptr);
546 memset(phdr, 0, sizeof(*phdr));
547 phdr->p_type = PT_NOTE;
548 phdr->p_offset = notes_offset;
549 phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
550 phdr->p_memsz = phdr->p_filesz;
555 * Create ELF core header (new kernel)
557 int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
559 Elf64_Phdr *phdr_notes, *phdr_loads;
565 /* If we are not in kdump or zfcpdump mode return */
566 if (!OLDMEM_BASE && ipl_info.type != IPL_TYPE_FCP_DUMP)
568 /* If elfcorehdr= has been passed via cmdline, we use that one */
569 if (elfcorehdr_addr != ELFCORE_ADDR_MAX)
571 /* If we cannot get HSA size for zfcpdump return error */
572 if (ipl_info.type == IPL_TYPE_FCP_DUMP && !sclp_get_hsa_size())
575 /* For kdump, exclude previous crashkernel memory */
577 oldmem_region.base = OLDMEM_BASE;
578 oldmem_region.size = OLDMEM_SIZE;
579 oldmem_type.total_size = OLDMEM_SIZE;
582 mem_chunk_cnt = get_mem_chunk_cnt();
584 alloc_size = 0x1000 + get_cpu_cnt() * 0x300 +
585 mem_chunk_cnt * sizeof(Elf64_Phdr);
586 hdr = kzalloc_panic(alloc_size);
587 /* Init elf header */
588 ptr = ehdr_init(hdr, mem_chunk_cnt);
589 /* Init program headers */
591 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
593 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
595 hdr_off = PTR_DIFF(ptr, hdr);
596 ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
598 hdr_off = PTR_DIFF(ptr, hdr);
599 loads_init(phdr_loads, hdr_off);
600 *addr = (unsigned long long) hdr;
601 elfcorehdr_newmem = hdr;
602 *size = (unsigned long long) hdr_off;
603 BUG_ON(elfcorehdr_size > alloc_size);
608 * Free ELF core header (new kernel)
610 void elfcorehdr_free(unsigned long long addr)
612 if (!elfcorehdr_newmem)
614 kfree((void *)(unsigned long)addr);
618 * Read from ELF header
620 ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
622 void *src = (void *)(unsigned long)*ppos;
624 src = elfcorehdr_newmem ? src : src - OLDMEM_BASE;
625 memcpy(buf, src, count);
631 * Read from ELF notes data
633 ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
635 void *src = (void *)(unsigned long)*ppos;
638 if (elfcorehdr_newmem) {
639 memcpy(buf, src, count);
641 rc = copy_from_oldmem(buf, src, count);