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 #define LINUX_NOTE_NAME "LINUX"
28 static struct memblock_region oldmem_region;
30 static struct memblock_type oldmem_type = {
34 .regions = &oldmem_region,
37 struct dump_save_areas dump_save_areas;
40 * Return physical address for virtual address
42 static inline void *load_real_addr(void *addr)
44 unsigned long real_addr;
51 : "=a" (real_addr) : "a" (addr) : "cc");
52 return (void *)real_addr;
56 * Copy real to virtual or real memory
58 static int copy_from_realmem(void *dest, void *src, size_t count)
64 if (!is_vmalloc_or_module_addr(dest))
65 return memcpy_real(dest, src, count);
67 size = min(count, PAGE_SIZE - (__pa(dest) & ~PAGE_MASK));
68 if (memcpy_real(load_real_addr(dest), src, size))
78 * Pointer to ELF header in new kernel
80 static void *elfcorehdr_newmem;
83 * Copy one page from zfcpdump "oldmem"
85 * For pages below HSA size memory from the HSA is copied. Otherwise
86 * real memory copy is used.
88 static ssize_t copy_oldmem_page_zfcpdump(char *buf, size_t csize,
89 unsigned long src, int userbuf)
93 if (src < sclp.hsa_size) {
94 rc = memcpy_hsa(buf, src, csize, userbuf);
97 rc = copy_to_user_real((void __force __user *) buf,
100 rc = memcpy_real(buf, (void *) src, csize);
102 return rc ? rc : csize;
106 * Copy one page from kdump "oldmem"
108 * For the kdump reserved memory this functions performs a swap operation:
109 * - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE].
110 * - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
112 static ssize_t copy_oldmem_page_kdump(char *buf, size_t csize,
113 unsigned long src, int userbuf)
118 if (src < OLDMEM_SIZE)
120 else if (src > OLDMEM_BASE &&
121 src < OLDMEM_BASE + OLDMEM_SIZE)
124 rc = copy_to_user_real((void __force __user *) buf,
125 (void *) src, csize);
127 rc = copy_from_realmem(buf, (void *) src, csize);
128 return (rc == 0) ? rc : csize;
132 * Copy one page from "oldmem"
134 ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
135 unsigned long offset, int userbuf)
141 src = (pfn << PAGE_SHIFT) + offset;
143 return copy_oldmem_page_kdump(buf, csize, src, userbuf);
145 return copy_oldmem_page_zfcpdump(buf, csize, src, userbuf);
149 * Remap "oldmem" for kdump
151 * For the kdump reserved memory this functions performs a swap operation:
152 * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
154 static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
155 unsigned long from, unsigned long pfn,
156 unsigned long size, pgprot_t prot)
158 unsigned long size_old;
161 if (pfn < OLDMEM_SIZE >> PAGE_SHIFT) {
162 size_old = min(size, OLDMEM_SIZE - (pfn << PAGE_SHIFT));
163 rc = remap_pfn_range(vma, from,
164 pfn + (OLDMEM_BASE >> PAGE_SHIFT),
166 if (rc || size == size_old)
170 pfn += size_old >> PAGE_SHIFT;
172 return remap_pfn_range(vma, from, pfn, size, prot);
176 * Remap "oldmem" for zfcpdump
178 * We only map available memory above HSA size. Memory below HSA size
179 * is read on demand using the copy_oldmem_page() function.
181 static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
184 unsigned long size, pgprot_t prot)
186 unsigned long hsa_end = sclp.hsa_size;
187 unsigned long size_hsa;
189 if (pfn < hsa_end >> PAGE_SHIFT) {
190 size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT));
191 if (size == size_hsa)
195 pfn += size_hsa >> PAGE_SHIFT;
197 return remap_pfn_range(vma, from, pfn, size, prot);
201 * Remap "oldmem" for kdump or zfcpdump
203 int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
204 unsigned long pfn, unsigned long size, pgprot_t prot)
207 return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
209 return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
214 * Copy memory from old kernel
216 int copy_from_oldmem(void *dest, void *src, size_t count)
218 unsigned long copied = 0;
222 if ((unsigned long) src < OLDMEM_SIZE) {
223 copied = min(count, OLDMEM_SIZE - (unsigned long) src);
224 rc = copy_from_realmem(dest, src + OLDMEM_BASE, copied);
229 unsigned long hsa_end = sclp.hsa_size;
230 if ((unsigned long) src < hsa_end) {
231 copied = min(count, hsa_end - (unsigned long) src);
232 rc = memcpy_hsa(dest, (unsigned long) src, copied, 0);
237 return copy_from_realmem(dest + copied, src + copied, count - copied);
241 * Alloc memory and panic in case of ENOMEM
243 static void *kzalloc_panic(int len)
247 rc = kzalloc(len, GFP_KERNEL);
249 panic("s390 kdump kzalloc (%d) failed", len);
254 * Initialize ELF note
256 static void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len,
262 note = (Elf64_Nhdr *)buf;
263 note->n_namesz = strlen(name) + 1;
264 note->n_descsz = d_len;
266 len = sizeof(Elf64_Nhdr);
268 memcpy(buf + len, name, note->n_namesz);
269 len = roundup(len + note->n_namesz, 4);
271 memcpy(buf + len, desc, note->n_descsz);
272 len = roundup(len + note->n_descsz, 4);
274 return PTR_ADD(buf, len);
278 * Initialize prstatus note
280 static void *nt_prstatus(void *ptr, struct save_area *sa)
282 struct elf_prstatus nt_prstatus;
283 static int cpu_nr = 1;
285 memset(&nt_prstatus, 0, sizeof(nt_prstatus));
286 memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs));
287 memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
288 memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs));
289 nt_prstatus.pr_pid = cpu_nr;
292 return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus),
297 * Initialize fpregset (floating point) note
299 static void *nt_fpregset(void *ptr, struct save_area *sa)
301 elf_fpregset_t nt_fpregset;
303 memset(&nt_fpregset, 0, sizeof(nt_fpregset));
304 memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg));
305 memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs));
307 return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset),
312 * Initialize timer note
314 static void *nt_s390_timer(void *ptr, struct save_area *sa)
316 return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer),
321 * Initialize TOD clock comparator note
323 static void *nt_s390_tod_cmp(void *ptr, struct save_area *sa)
325 return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp,
326 sizeof(sa->clk_cmp), LINUX_NOTE_NAME);
330 * Initialize TOD programmable register note
332 static void *nt_s390_tod_preg(void *ptr, struct save_area *sa)
334 return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg,
335 sizeof(sa->tod_reg), LINUX_NOTE_NAME);
339 * Initialize control register note
341 static void *nt_s390_ctrs(void *ptr, struct save_area *sa)
343 return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs,
344 sizeof(sa->ctrl_regs), LINUX_NOTE_NAME);
348 * Initialize prefix register note
350 static void *nt_s390_prefix(void *ptr, struct save_area *sa)
352 return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg,
353 sizeof(sa->pref_reg), LINUX_NOTE_NAME);
357 * Initialize vxrs high note (full 128 bit VX registers 16-31)
359 static void *nt_s390_vx_high(void *ptr, __vector128 *vx_regs)
361 return nt_init(ptr, NT_S390_VXRS_HIGH, &vx_regs[16],
362 16 * sizeof(__vector128), LINUX_NOTE_NAME);
366 * Initialize vxrs low note (lower halves of VX registers 0-15)
368 static void *nt_s390_vx_low(void *ptr, __vector128 *vx_regs)
374 note = (Elf64_Nhdr *)ptr;
375 note->n_namesz = strlen(LINUX_NOTE_NAME) + 1;
376 note->n_descsz = 16 * 8;
377 note->n_type = NT_S390_VXRS_LOW;
378 len = sizeof(Elf64_Nhdr);
380 memcpy(ptr + len, LINUX_NOTE_NAME, note->n_namesz);
381 len = roundup(len + note->n_namesz, 4);
384 /* Copy lower halves of SIMD registers 0-15 */
385 for (i = 0; i < 16; i++) {
386 memcpy(ptr, &vx_regs[i].u[2], 8);
393 * Fill ELF notes for one CPU with save area registers
395 void *fill_cpu_elf_notes(void *ptr, struct save_area *sa, __vector128 *vx_regs)
397 ptr = nt_prstatus(ptr, sa);
398 ptr = nt_fpregset(ptr, sa);
399 ptr = nt_s390_timer(ptr, sa);
400 ptr = nt_s390_tod_cmp(ptr, sa);
401 ptr = nt_s390_tod_preg(ptr, sa);
402 ptr = nt_s390_ctrs(ptr, sa);
403 ptr = nt_s390_prefix(ptr, sa);
404 if (MACHINE_HAS_VX && vx_regs) {
405 ptr = nt_s390_vx_low(ptr, vx_regs);
406 ptr = nt_s390_vx_high(ptr, vx_regs);
412 * Initialize prpsinfo note (new kernel)
414 static void *nt_prpsinfo(void *ptr)
416 struct elf_prpsinfo prpsinfo;
418 memset(&prpsinfo, 0, sizeof(prpsinfo));
419 prpsinfo.pr_sname = 'R';
420 strcpy(prpsinfo.pr_fname, "vmlinux");
421 return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo),
422 KEXEC_CORE_NOTE_NAME);
426 * Get vmcoreinfo using lowcore->vmcore_info (new kernel)
428 static void *get_vmcoreinfo_old(unsigned long *size)
430 char nt_name[11], *vmcoreinfo;
434 if (copy_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
436 memset(nt_name, 0, sizeof(nt_name));
437 if (copy_from_oldmem(¬e, addr, sizeof(note)))
439 if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1))
441 if (strcmp(nt_name, "VMCOREINFO") != 0)
443 vmcoreinfo = kzalloc_panic(note.n_descsz);
444 if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz))
446 *size = note.n_descsz;
451 * Initialize vmcoreinfo note (new kernel)
453 static void *nt_vmcoreinfo(void *ptr)
458 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
460 vmcoreinfo = get_vmcoreinfo_old(&size);
463 return nt_init(ptr, 0, vmcoreinfo, size, "VMCOREINFO");
467 * Initialize final note (needed for /proc/vmcore code)
469 static void *nt_final(void *ptr)
473 note = (Elf64_Nhdr *) ptr;
477 return PTR_ADD(ptr, sizeof(Elf64_Nhdr));
481 * Initialize ELF header (new kernel)
483 static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt)
485 memset(ehdr, 0, sizeof(*ehdr));
486 memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
487 ehdr->e_ident[EI_CLASS] = ELFCLASS64;
488 ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
489 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
490 memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
491 ehdr->e_type = ET_CORE;
492 ehdr->e_machine = EM_S390;
493 ehdr->e_version = EV_CURRENT;
494 ehdr->e_phoff = sizeof(Elf64_Ehdr);
495 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
496 ehdr->e_phentsize = sizeof(Elf64_Phdr);
497 ehdr->e_phnum = mem_chunk_cnt + 1;
502 * Return CPU count for ELF header (new kernel)
504 static int get_cpu_cnt(void)
508 for (i = 0; i < dump_save_areas.count; i++) {
509 if (dump_save_areas.areas[i]->sa.pref_reg == 0)
517 * Return memory chunk count for ELF header (new kernel)
519 static int get_mem_chunk_cnt(void)
524 for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
525 MEMBLOCK_NONE, NULL, NULL, NULL)
531 * Initialize ELF loads (new kernel)
533 static void loads_init(Elf64_Phdr *phdr, u64 loads_offset)
535 phys_addr_t start, end;
538 for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
539 MEMBLOCK_NONE, &start, &end, NULL) {
540 phdr->p_filesz = end - start;
541 phdr->p_type = PT_LOAD;
542 phdr->p_offset = start;
543 phdr->p_vaddr = start;
544 phdr->p_paddr = start;
545 phdr->p_memsz = end - start;
546 phdr->p_flags = PF_R | PF_W | PF_X;
547 phdr->p_align = PAGE_SIZE;
553 * Initialize notes (new kernel)
555 static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
557 struct save_area_ext *sa_ext;
558 void *ptr_start = ptr;
561 ptr = nt_prpsinfo(ptr);
563 for (i = 0; i < dump_save_areas.count; i++) {
564 sa_ext = dump_save_areas.areas[i];
565 if (sa_ext->sa.pref_reg == 0)
567 ptr = fill_cpu_elf_notes(ptr, &sa_ext->sa, sa_ext->vx_regs);
569 ptr = nt_vmcoreinfo(ptr);
571 memset(phdr, 0, sizeof(*phdr));
572 phdr->p_type = PT_NOTE;
573 phdr->p_offset = notes_offset;
574 phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
575 phdr->p_memsz = phdr->p_filesz;
580 * Create ELF core header (new kernel)
582 int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
584 Elf64_Phdr *phdr_notes, *phdr_loads;
590 /* If we are not in kdump or zfcpdump mode return */
591 if (!OLDMEM_BASE && ipl_info.type != IPL_TYPE_FCP_DUMP)
593 /* If elfcorehdr= has been passed via cmdline, we use that one */
594 if (elfcorehdr_addr != ELFCORE_ADDR_MAX)
596 /* If we cannot get HSA size for zfcpdump return error */
597 if (ipl_info.type == IPL_TYPE_FCP_DUMP && !sclp.hsa_size)
600 /* For kdump, exclude previous crashkernel memory */
602 oldmem_region.base = OLDMEM_BASE;
603 oldmem_region.size = OLDMEM_SIZE;
604 oldmem_type.total_size = OLDMEM_SIZE;
607 mem_chunk_cnt = get_mem_chunk_cnt();
609 alloc_size = 0x1000 + get_cpu_cnt() * 0x4a0 +
610 mem_chunk_cnt * sizeof(Elf64_Phdr);
611 hdr = kzalloc_panic(alloc_size);
612 /* Init elf header */
613 ptr = ehdr_init(hdr, mem_chunk_cnt);
614 /* Init program headers */
616 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
618 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
620 hdr_off = PTR_DIFF(ptr, hdr);
621 ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
623 hdr_off = PTR_DIFF(ptr, hdr);
624 loads_init(phdr_loads, hdr_off);
625 *addr = (unsigned long long) hdr;
626 elfcorehdr_newmem = hdr;
627 *size = (unsigned long long) hdr_off;
628 BUG_ON(elfcorehdr_size > alloc_size);
633 * Free ELF core header (new kernel)
635 void elfcorehdr_free(unsigned long long addr)
637 if (!elfcorehdr_newmem)
639 kfree((void *)(unsigned long)addr);
643 * Read from ELF header
645 ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
647 void *src = (void *)(unsigned long)*ppos;
649 src = elfcorehdr_newmem ? src : src - OLDMEM_BASE;
650 memcpy(buf, src, count);
656 * Read from ELF notes data
658 ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
660 void *src = (void *)(unsigned long)*ppos;
663 if (elfcorehdr_newmem) {
664 memcpy(buf, src, count);
666 rc = copy_from_oldmem(buf, src, count);