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_NONE, \
38 &oldmem_type, p_start, \
40 i != (u64)ULLONG_MAX; \
41 __next_mem_range(&i, nid, MEMBLOCK_NONE, &memblock.physmem,\
43 p_start, p_end, p_nid))
45 struct dump_save_areas dump_save_areas;
48 * Allocate and add a save area for a CPU
50 struct save_area_ext *dump_save_area_create(int cpu)
52 struct save_area_ext **save_areas, *save_area;
54 save_area = kmalloc(sizeof(*save_area), GFP_KERNEL);
57 if (cpu + 1 > dump_save_areas.count) {
58 dump_save_areas.count = cpu + 1;
59 save_areas = krealloc(dump_save_areas.areas,
60 dump_save_areas.count * sizeof(void *),
61 GFP_KERNEL | __GFP_ZERO);
66 dump_save_areas.areas = save_areas;
68 dump_save_areas.areas[cpu] = save_area;
73 * Return physical address for virtual address
75 static inline void *load_real_addr(void *addr)
77 unsigned long real_addr;
84 : "=a" (real_addr) : "a" (addr) : "cc");
85 return (void *)real_addr;
89 * Copy real to virtual or real memory
91 static int copy_from_realmem(void *dest, void *src, size_t count)
97 if (!is_vmalloc_or_module_addr(dest))
98 return memcpy_real(dest, src, count);
100 size = min(count, PAGE_SIZE - (__pa(dest) & ~PAGE_MASK));
101 if (memcpy_real(load_real_addr(dest), src, size))
111 * Pointer to ELF header in new kernel
113 static void *elfcorehdr_newmem;
116 * Copy one page from zfcpdump "oldmem"
118 * For pages below HSA size memory from the HSA is copied. Otherwise
119 * real memory copy is used.
121 static ssize_t copy_oldmem_page_zfcpdump(char *buf, size_t csize,
122 unsigned long src, int userbuf)
126 if (src < sclp.hsa_size) {
127 rc = memcpy_hsa(buf, src, csize, userbuf);
130 rc = copy_to_user_real((void __force __user *) buf,
131 (void *) src, csize);
133 rc = memcpy_real(buf, (void *) src, csize);
135 return rc ? rc : csize;
139 * Copy one page from kdump "oldmem"
141 * For the kdump reserved memory this functions performs a swap operation:
142 * - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE].
143 * - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
145 static ssize_t copy_oldmem_page_kdump(char *buf, size_t csize,
146 unsigned long src, int userbuf)
151 if (src < OLDMEM_SIZE)
153 else if (src > OLDMEM_BASE &&
154 src < OLDMEM_BASE + OLDMEM_SIZE)
157 rc = copy_to_user_real((void __force __user *) buf,
158 (void *) src, csize);
160 rc = copy_from_realmem(buf, (void *) src, csize);
161 return (rc == 0) ? rc : csize;
165 * Copy one page from "oldmem"
167 ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
168 unsigned long offset, int userbuf)
174 src = (pfn << PAGE_SHIFT) + offset;
176 return copy_oldmem_page_kdump(buf, csize, src, userbuf);
178 return copy_oldmem_page_zfcpdump(buf, csize, src, userbuf);
182 * Remap "oldmem" for kdump
184 * For the kdump reserved memory this functions performs a swap operation:
185 * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
187 static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
188 unsigned long from, unsigned long pfn,
189 unsigned long size, pgprot_t prot)
191 unsigned long size_old;
194 if (pfn < OLDMEM_SIZE >> PAGE_SHIFT) {
195 size_old = min(size, OLDMEM_SIZE - (pfn << PAGE_SHIFT));
196 rc = remap_pfn_range(vma, from,
197 pfn + (OLDMEM_BASE >> PAGE_SHIFT),
199 if (rc || size == size_old)
203 pfn += size_old >> PAGE_SHIFT;
205 return remap_pfn_range(vma, from, pfn, size, prot);
209 * Remap "oldmem" for zfcpdump
211 * We only map available memory above HSA size. Memory below HSA size
212 * is read on demand using the copy_oldmem_page() function.
214 static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
217 unsigned long size, pgprot_t prot)
219 unsigned long hsa_end = sclp.hsa_size;
220 unsigned long size_hsa;
222 if (pfn < hsa_end >> PAGE_SHIFT) {
223 size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT));
224 if (size == size_hsa)
228 pfn += size_hsa >> PAGE_SHIFT;
230 return remap_pfn_range(vma, from, pfn, size, prot);
234 * Remap "oldmem" for kdump or zfcpdump
236 int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
237 unsigned long pfn, unsigned long size, pgprot_t prot)
240 return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
242 return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
247 * Copy memory from old kernel
249 int copy_from_oldmem(void *dest, void *src, size_t count)
251 unsigned long copied = 0;
255 if ((unsigned long) src < OLDMEM_SIZE) {
256 copied = min(count, OLDMEM_SIZE - (unsigned long) src);
257 rc = copy_from_realmem(dest, src + OLDMEM_BASE, copied);
262 unsigned long hsa_end = sclp.hsa_size;
263 if ((unsigned long) src < hsa_end) {
264 copied = min(count, hsa_end - (unsigned long) src);
265 rc = memcpy_hsa(dest, (unsigned long) src, copied, 0);
270 return copy_from_realmem(dest + copied, src + copied, count - copied);
274 * Alloc memory and panic in case of ENOMEM
276 static void *kzalloc_panic(int len)
280 rc = kzalloc(len, GFP_KERNEL);
282 panic("s390 kdump kzalloc (%d) failed", len);
287 * Initialize ELF note
289 static void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len,
295 note = (Elf64_Nhdr *)buf;
296 note->n_namesz = strlen(name) + 1;
297 note->n_descsz = d_len;
299 len = sizeof(Elf64_Nhdr);
301 memcpy(buf + len, name, note->n_namesz);
302 len = roundup(len + note->n_namesz, 4);
304 memcpy(buf + len, desc, note->n_descsz);
305 len = roundup(len + note->n_descsz, 4);
307 return PTR_ADD(buf, len);
311 * Initialize prstatus note
313 static void *nt_prstatus(void *ptr, struct save_area *sa)
315 struct elf_prstatus nt_prstatus;
316 static int cpu_nr = 1;
318 memset(&nt_prstatus, 0, sizeof(nt_prstatus));
319 memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs));
320 memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
321 memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs));
322 nt_prstatus.pr_pid = cpu_nr;
325 return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus),
330 * Initialize fpregset (floating point) note
332 static void *nt_fpregset(void *ptr, struct save_area *sa)
334 elf_fpregset_t nt_fpregset;
336 memset(&nt_fpregset, 0, sizeof(nt_fpregset));
337 memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg));
338 memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs));
340 return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset),
345 * Initialize timer note
347 static void *nt_s390_timer(void *ptr, struct save_area *sa)
349 return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer),
350 KEXEC_CORE_NOTE_NAME);
354 * Initialize TOD clock comparator note
356 static void *nt_s390_tod_cmp(void *ptr, struct save_area *sa)
358 return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp,
359 sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME);
363 * Initialize TOD programmable register note
365 static void *nt_s390_tod_preg(void *ptr, struct save_area *sa)
367 return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg,
368 sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME);
372 * Initialize control register note
374 static void *nt_s390_ctrs(void *ptr, struct save_area *sa)
376 return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs,
377 sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME);
381 * Initialize prefix register note
383 static void *nt_s390_prefix(void *ptr, struct save_area *sa)
385 return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg,
386 sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME);
390 * Initialize vxrs high note (full 128 bit VX registers 16-31)
392 static void *nt_s390_vx_high(void *ptr, __vector128 *vx_regs)
394 return nt_init(ptr, NT_S390_VXRS_HIGH, &vx_regs[16],
395 16 * sizeof(__vector128), KEXEC_CORE_NOTE_NAME);
399 * Initialize vxrs low note (lower halves of VX registers 0-15)
401 static void *nt_s390_vx_low(void *ptr, __vector128 *vx_regs)
407 note = (Elf64_Nhdr *)ptr;
408 note->n_namesz = strlen(KEXEC_CORE_NOTE_NAME) + 1;
409 note->n_descsz = 16 * 8;
410 note->n_type = NT_S390_VXRS_LOW;
411 len = sizeof(Elf64_Nhdr);
413 memcpy(ptr + len, KEXEC_CORE_NOTE_NAME, note->n_namesz);
414 len = roundup(len + note->n_namesz, 4);
417 /* Copy lower halves of SIMD registers 0-15 */
418 for (i = 0; i < 16; i++) {
419 memcpy(ptr, &vx_regs[i], 8);
426 * Fill ELF notes for one CPU with save area registers
428 void *fill_cpu_elf_notes(void *ptr, struct save_area *sa, __vector128 *vx_regs)
430 ptr = nt_prstatus(ptr, sa);
431 ptr = nt_fpregset(ptr, sa);
432 ptr = nt_s390_timer(ptr, sa);
433 ptr = nt_s390_tod_cmp(ptr, sa);
434 ptr = nt_s390_tod_preg(ptr, sa);
435 ptr = nt_s390_ctrs(ptr, sa);
436 ptr = nt_s390_prefix(ptr, sa);
437 if (MACHINE_HAS_VX && vx_regs) {
438 ptr = nt_s390_vx_low(ptr, vx_regs);
439 ptr = nt_s390_vx_high(ptr, vx_regs);
445 * Initialize prpsinfo note (new kernel)
447 static void *nt_prpsinfo(void *ptr)
449 struct elf_prpsinfo prpsinfo;
451 memset(&prpsinfo, 0, sizeof(prpsinfo));
452 prpsinfo.pr_sname = 'R';
453 strcpy(prpsinfo.pr_fname, "vmlinux");
454 return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo),
455 KEXEC_CORE_NOTE_NAME);
459 * Get vmcoreinfo using lowcore->vmcore_info (new kernel)
461 static void *get_vmcoreinfo_old(unsigned long *size)
463 char nt_name[11], *vmcoreinfo;
467 if (copy_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
469 memset(nt_name, 0, sizeof(nt_name));
470 if (copy_from_oldmem(¬e, addr, sizeof(note)))
472 if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1))
474 if (strcmp(nt_name, "VMCOREINFO") != 0)
476 vmcoreinfo = kzalloc_panic(note.n_descsz);
477 if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz))
479 *size = note.n_descsz;
484 * Initialize vmcoreinfo note (new kernel)
486 static void *nt_vmcoreinfo(void *ptr)
491 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
493 vmcoreinfo = get_vmcoreinfo_old(&size);
496 return nt_init(ptr, 0, vmcoreinfo, size, "VMCOREINFO");
500 * Initialize ELF header (new kernel)
502 static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt)
504 memset(ehdr, 0, sizeof(*ehdr));
505 memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
506 ehdr->e_ident[EI_CLASS] = ELFCLASS64;
507 ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
508 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
509 memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
510 ehdr->e_type = ET_CORE;
511 ehdr->e_machine = EM_S390;
512 ehdr->e_version = EV_CURRENT;
513 ehdr->e_phoff = sizeof(Elf64_Ehdr);
514 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
515 ehdr->e_phentsize = sizeof(Elf64_Phdr);
516 ehdr->e_phnum = mem_chunk_cnt + 1;
521 * Return CPU count for ELF header (new kernel)
523 static int get_cpu_cnt(void)
527 for (i = 0; i < dump_save_areas.count; i++) {
528 if (dump_save_areas.areas[i]->sa.pref_reg == 0)
536 * Return memory chunk count for ELF header (new kernel)
538 static int get_mem_chunk_cnt(void)
543 for_each_dump_mem_range(idx, NUMA_NO_NODE, NULL, NULL, NULL)
549 * Initialize ELF loads (new kernel)
551 static void loads_init(Elf64_Phdr *phdr, u64 loads_offset)
553 phys_addr_t start, end;
556 for_each_dump_mem_range(idx, NUMA_NO_NODE, &start, &end, NULL) {
557 phdr->p_filesz = end - start;
558 phdr->p_type = PT_LOAD;
559 phdr->p_offset = start;
560 phdr->p_vaddr = start;
561 phdr->p_paddr = start;
562 phdr->p_memsz = end - start;
563 phdr->p_flags = PF_R | PF_W | PF_X;
564 phdr->p_align = PAGE_SIZE;
570 * Initialize notes (new kernel)
572 static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
574 struct save_area_ext *sa_ext;
575 void *ptr_start = ptr;
578 ptr = nt_prpsinfo(ptr);
580 for (i = 0; i < dump_save_areas.count; i++) {
581 sa_ext = dump_save_areas.areas[i];
582 if (sa_ext->sa.pref_reg == 0)
584 ptr = fill_cpu_elf_notes(ptr, &sa_ext->sa, sa_ext->vx_regs);
586 ptr = nt_vmcoreinfo(ptr);
587 memset(phdr, 0, sizeof(*phdr));
588 phdr->p_type = PT_NOTE;
589 phdr->p_offset = notes_offset;
590 phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
591 phdr->p_memsz = phdr->p_filesz;
596 * Create ELF core header (new kernel)
598 int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
600 Elf64_Phdr *phdr_notes, *phdr_loads;
606 /* If we are not in kdump or zfcpdump mode return */
607 if (!OLDMEM_BASE && ipl_info.type != IPL_TYPE_FCP_DUMP)
609 /* If elfcorehdr= has been passed via cmdline, we use that one */
610 if (elfcorehdr_addr != ELFCORE_ADDR_MAX)
612 /* If we cannot get HSA size for zfcpdump return error */
613 if (ipl_info.type == IPL_TYPE_FCP_DUMP && !sclp.hsa_size)
616 /* For kdump, exclude previous crashkernel memory */
618 oldmem_region.base = OLDMEM_BASE;
619 oldmem_region.size = OLDMEM_SIZE;
620 oldmem_type.total_size = OLDMEM_SIZE;
623 mem_chunk_cnt = get_mem_chunk_cnt();
625 alloc_size = 0x1000 + get_cpu_cnt() * 0x4a0 +
626 mem_chunk_cnt * sizeof(Elf64_Phdr);
627 hdr = kzalloc_panic(alloc_size);
628 /* Init elf header */
629 ptr = ehdr_init(hdr, mem_chunk_cnt);
630 /* Init program headers */
632 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
634 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
636 hdr_off = PTR_DIFF(ptr, hdr);
637 ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
639 hdr_off = PTR_DIFF(ptr, hdr);
640 loads_init(phdr_loads, hdr_off);
641 *addr = (unsigned long long) hdr;
642 elfcorehdr_newmem = hdr;
643 *size = (unsigned long long) hdr_off;
644 BUG_ON(elfcorehdr_size > alloc_size);
649 * Free ELF core header (new kernel)
651 void elfcorehdr_free(unsigned long long addr)
653 if (!elfcorehdr_newmem)
655 kfree((void *)(unsigned long)addr);
659 * Read from ELF header
661 ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
663 void *src = (void *)(unsigned long)*ppos;
665 src = elfcorehdr_newmem ? src : src - OLDMEM_BASE;
666 memcpy(buf, src, count);
672 * Read from ELF notes data
674 ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
676 void *src = (void *)(unsigned long)*ppos;
679 if (elfcorehdr_newmem) {
680 memcpy(buf, src, count);
682 rc = copy_from_oldmem(buf, src, count);