linux/arch/s390/kernel/crash_dump.c
Michael Holzheu e657d8fe2f s390/sclp: Determine HSA size dynamically for zfcpdump
Currently we have hardcoded the HSA size to 32 MiB. With this patch the
HSA size is determined dynamically via SCLP in early.c.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-11-15 14:08:40 +01:00

653 lines
15 KiB
C

/*
* S390 kdump implementation
*
* Copyright IBM Corp. 2011
* Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
*/
#include <linux/crash_dump.h>
#include <asm/lowcore.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/bootmem.h>
#include <linux/elf.h>
#include <asm/os_info.h>
#include <asm/elf.h>
#include <asm/ipl.h>
#include <asm/sclp.h>
#define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
#define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
#define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
struct dump_save_areas dump_save_areas;
/*
* Allocate and add a save area for a CPU
*/
struct save_area *dump_save_area_create(int cpu)
{
struct save_area **save_areas, *save_area;
save_area = kmalloc(sizeof(*save_area), GFP_KERNEL);
if (!save_area)
return NULL;
if (cpu + 1 > dump_save_areas.count) {
dump_save_areas.count = cpu + 1;
save_areas = krealloc(dump_save_areas.areas,
dump_save_areas.count * sizeof(void *),
GFP_KERNEL | __GFP_ZERO);
if (!save_areas) {
kfree(save_area);
return NULL;
}
dump_save_areas.areas = save_areas;
}
dump_save_areas.areas[cpu] = save_area;
return save_area;
}
/*
* Return physical address for virtual address
*/
static inline void *load_real_addr(void *addr)
{
unsigned long real_addr;
asm volatile(
" lra %0,0(%1)\n"
" jz 0f\n"
" la %0,0\n"
"0:"
: "=a" (real_addr) : "a" (addr) : "cc");
return (void *)real_addr;
}
/*
* Copy real to virtual or real memory
*/
static int copy_from_realmem(void *dest, void *src, size_t count)
{
unsigned long size;
if (!count)
return 0;
if (!is_vmalloc_or_module_addr(dest))
return memcpy_real(dest, src, count);
do {
size = min(count, PAGE_SIZE - (__pa(dest) & ~PAGE_MASK));
if (memcpy_real(load_real_addr(dest), src, size))
return -EFAULT;
count -= size;
dest += size;
src += size;
} while (count);
return 0;
}
/*
* Pointer to ELF header in new kernel
*/
static void *elfcorehdr_newmem;
/*
* Copy one page from zfcpdump "oldmem"
*
* For pages below HSA size memory from the HSA is copied. Otherwise
* real memory copy is used.
*/
static ssize_t copy_oldmem_page_zfcpdump(char *buf, size_t csize,
unsigned long src, int userbuf)
{
int rc;
if (src < sclp_get_hsa_size()) {
rc = memcpy_hsa(buf, src, csize, userbuf);
} else {
if (userbuf)
rc = copy_to_user_real((void __force __user *) buf,
(void *) src, csize);
else
rc = memcpy_real(buf, (void *) src, csize);
}
return rc ? rc : csize;
}
/*
* Copy one page from kdump "oldmem"
*
* For the kdump reserved memory this functions performs a swap operation:
* - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE].
* - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
*/
static ssize_t copy_oldmem_page_kdump(char *buf, size_t csize,
unsigned long src, int userbuf)
{
int rc;
if (src < OLDMEM_SIZE)
src += OLDMEM_BASE;
else if (src > OLDMEM_BASE &&
src < OLDMEM_BASE + OLDMEM_SIZE)
src -= OLDMEM_BASE;
if (userbuf)
rc = copy_to_user_real((void __force __user *) buf,
(void *) src, csize);
else
rc = copy_from_realmem(buf, (void *) src, csize);
return (rc == 0) ? rc : csize;
}
/*
* Copy one page from "oldmem"
*/
ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
unsigned long offset, int userbuf)
{
unsigned long src;
if (!csize)
return 0;
src = (pfn << PAGE_SHIFT) + offset;
if (OLDMEM_BASE)
return copy_oldmem_page_kdump(buf, csize, src, userbuf);
else
return copy_oldmem_page_zfcpdump(buf, csize, src, userbuf);
}
/*
* Remap "oldmem" for kdump
*
* For the kdump reserved memory this functions performs a swap operation:
* [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
*/
static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
unsigned long from, unsigned long pfn,
unsigned long size, pgprot_t prot)
{
unsigned long size_old;
int rc;
if (pfn < OLDMEM_SIZE >> PAGE_SHIFT) {
size_old = min(size, OLDMEM_SIZE - (pfn << PAGE_SHIFT));
rc = remap_pfn_range(vma, from,
pfn + (OLDMEM_BASE >> PAGE_SHIFT),
size_old, prot);
if (rc || size == size_old)
return rc;
size -= size_old;
from += size_old;
pfn += size_old >> PAGE_SHIFT;
}
return remap_pfn_range(vma, from, pfn, size, prot);
}
/*
* Remap "oldmem" for zfcpdump
*
* We only map available memory above HSA size. Memory below HSA size
* is read on demand using the copy_oldmem_page() function.
*/
static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
unsigned long from,
unsigned long pfn,
unsigned long size, pgprot_t prot)
{
unsigned long hsa_end = sclp_get_hsa_size();
unsigned long size_hsa;
if (pfn < hsa_end >> PAGE_SHIFT) {
size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT));
if (size == size_hsa)
return 0;
size -= size_hsa;
from += size_hsa;
pfn += size_hsa >> PAGE_SHIFT;
}
return remap_pfn_range(vma, from, pfn, size, prot);
}
/*
* Remap "oldmem" for kdump or zfcpdump
*/
int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
unsigned long pfn, unsigned long size, pgprot_t prot)
{
if (OLDMEM_BASE)
return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
else
return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
prot);
}
/*
* Copy memory from old kernel
*/
int copy_from_oldmem(void *dest, void *src, size_t count)
{
unsigned long copied = 0;
int rc;
if (OLDMEM_BASE) {
if ((unsigned long) src < OLDMEM_SIZE) {
copied = min(count, OLDMEM_SIZE - (unsigned long) src);
rc = copy_from_realmem(dest, src + OLDMEM_BASE, copied);
if (rc)
return rc;
}
} else {
unsigned long hsa_end = sclp_get_hsa_size();
if ((unsigned long) src < hsa_end) {
copied = min(count, hsa_end - (unsigned long) src);
rc = memcpy_hsa(dest, (unsigned long) src, copied, 0);
if (rc)
return rc;
}
}
return copy_from_realmem(dest + copied, src + copied, count - copied);
}
/*
* Alloc memory and panic in case of ENOMEM
*/
static void *kzalloc_panic(int len)
{
void *rc;
rc = kzalloc(len, GFP_KERNEL);
if (!rc)
panic("s390 kdump kzalloc (%d) failed", len);
return rc;
}
/*
* Get memory layout and create hole for oldmem
*/
static struct mem_chunk *get_memory_layout(void)
{
struct mem_chunk *chunk_array;
chunk_array = kzalloc_panic(MEMORY_CHUNKS * sizeof(struct mem_chunk));
detect_memory_layout(chunk_array, 0);
create_mem_hole(chunk_array, OLDMEM_BASE, OLDMEM_SIZE);
return chunk_array;
}
/*
* Initialize ELF note
*/
static void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len,
const char *name)
{
Elf64_Nhdr *note;
u64 len;
note = (Elf64_Nhdr *)buf;
note->n_namesz = strlen(name) + 1;
note->n_descsz = d_len;
note->n_type = type;
len = sizeof(Elf64_Nhdr);
memcpy(buf + len, name, note->n_namesz);
len = roundup(len + note->n_namesz, 4);
memcpy(buf + len, desc, note->n_descsz);
len = roundup(len + note->n_descsz, 4);
return PTR_ADD(buf, len);
}
/*
* Initialize prstatus note
*/
static void *nt_prstatus(void *ptr, struct save_area *sa)
{
struct elf_prstatus nt_prstatus;
static int cpu_nr = 1;
memset(&nt_prstatus, 0, sizeof(nt_prstatus));
memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs));
memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs));
nt_prstatus.pr_pid = cpu_nr;
cpu_nr++;
return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus),
"CORE");
}
/*
* Initialize fpregset (floating point) note
*/
static void *nt_fpregset(void *ptr, struct save_area *sa)
{
elf_fpregset_t nt_fpregset;
memset(&nt_fpregset, 0, sizeof(nt_fpregset));
memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg));
memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs));
return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset),
"CORE");
}
/*
* Initialize timer note
*/
static void *nt_s390_timer(void *ptr, struct save_area *sa)
{
return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer),
KEXEC_CORE_NOTE_NAME);
}
/*
* Initialize TOD clock comparator note
*/
static void *nt_s390_tod_cmp(void *ptr, struct save_area *sa)
{
return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp,
sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME);
}
/*
* Initialize TOD programmable register note
*/
static void *nt_s390_tod_preg(void *ptr, struct save_area *sa)
{
return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg,
sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME);
}
/*
* Initialize control register note
*/
static void *nt_s390_ctrs(void *ptr, struct save_area *sa)
{
return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs,
sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME);
}
/*
* Initialize prefix register note
*/
static void *nt_s390_prefix(void *ptr, struct save_area *sa)
{
return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg,
sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME);
}
/*
* Fill ELF notes for one CPU with save area registers
*/
void *fill_cpu_elf_notes(void *ptr, struct save_area *sa)
{
ptr = nt_prstatus(ptr, sa);
ptr = nt_fpregset(ptr, sa);
ptr = nt_s390_timer(ptr, sa);
ptr = nt_s390_tod_cmp(ptr, sa);
ptr = nt_s390_tod_preg(ptr, sa);
ptr = nt_s390_ctrs(ptr, sa);
ptr = nt_s390_prefix(ptr, sa);
return ptr;
}
/*
* Initialize prpsinfo note (new kernel)
*/
static void *nt_prpsinfo(void *ptr)
{
struct elf_prpsinfo prpsinfo;
memset(&prpsinfo, 0, sizeof(prpsinfo));
prpsinfo.pr_sname = 'R';
strcpy(prpsinfo.pr_fname, "vmlinux");
return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo),
KEXEC_CORE_NOTE_NAME);
}
/*
* Get vmcoreinfo using lowcore->vmcore_info (new kernel)
*/
static void *get_vmcoreinfo_old(unsigned long *size)
{
char nt_name[11], *vmcoreinfo;
Elf64_Nhdr note;
void *addr;
if (copy_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
return NULL;
memset(nt_name, 0, sizeof(nt_name));
if (copy_from_oldmem(&note, addr, sizeof(note)))
return NULL;
if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1))
return NULL;
if (strcmp(nt_name, "VMCOREINFO") != 0)
return NULL;
vmcoreinfo = kzalloc_panic(note.n_descsz);
if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz))
return NULL;
*size = note.n_descsz;
return vmcoreinfo;
}
/*
* Initialize vmcoreinfo note (new kernel)
*/
static void *nt_vmcoreinfo(void *ptr)
{
unsigned long size;
void *vmcoreinfo;
vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
if (!vmcoreinfo)
vmcoreinfo = get_vmcoreinfo_old(&size);
if (!vmcoreinfo)
return ptr;
return nt_init(ptr, 0, vmcoreinfo, size, "VMCOREINFO");
}
/*
* Initialize ELF header (new kernel)
*/
static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt)
{
memset(ehdr, 0, sizeof(*ehdr));
memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
ehdr->e_ident[EI_CLASS] = ELFCLASS64;
ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
ehdr->e_ident[EI_VERSION] = EV_CURRENT;
memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
ehdr->e_type = ET_CORE;
ehdr->e_machine = EM_S390;
ehdr->e_version = EV_CURRENT;
ehdr->e_phoff = sizeof(Elf64_Ehdr);
ehdr->e_ehsize = sizeof(Elf64_Ehdr);
ehdr->e_phentsize = sizeof(Elf64_Phdr);
ehdr->e_phnum = mem_chunk_cnt + 1;
return ehdr + 1;
}
/*
* Return CPU count for ELF header (new kernel)
*/
static int get_cpu_cnt(void)
{
int i, cpus = 0;
for (i = 0; i < dump_save_areas.count; i++) {
if (dump_save_areas.areas[i]->pref_reg == 0)
continue;
cpus++;
}
return cpus;
}
/*
* Return memory chunk count for ELF header (new kernel)
*/
static int get_mem_chunk_cnt(void)
{
struct mem_chunk *chunk_array, *mem_chunk;
int i, cnt = 0;
chunk_array = get_memory_layout();
for (i = 0; i < MEMORY_CHUNKS; i++) {
mem_chunk = &chunk_array[i];
if (chunk_array[i].type != CHUNK_READ_WRITE &&
chunk_array[i].type != CHUNK_READ_ONLY)
continue;
if (mem_chunk->size == 0)
continue;
cnt++;
}
kfree(chunk_array);
return cnt;
}
/*
* Initialize ELF loads (new kernel)
*/
static int loads_init(Elf64_Phdr *phdr, u64 loads_offset)
{
struct mem_chunk *chunk_array, *mem_chunk;
int i;
chunk_array = get_memory_layout();
for (i = 0; i < MEMORY_CHUNKS; i++) {
mem_chunk = &chunk_array[i];
if (mem_chunk->size == 0)
continue;
if (chunk_array[i].type != CHUNK_READ_WRITE &&
chunk_array[i].type != CHUNK_READ_ONLY)
continue;
else
phdr->p_filesz = mem_chunk->size;
phdr->p_type = PT_LOAD;
phdr->p_offset = mem_chunk->addr;
phdr->p_vaddr = mem_chunk->addr;
phdr->p_paddr = mem_chunk->addr;
phdr->p_memsz = mem_chunk->size;
phdr->p_flags = PF_R | PF_W | PF_X;
phdr->p_align = PAGE_SIZE;
phdr++;
}
kfree(chunk_array);
return i;
}
/*
* Initialize notes (new kernel)
*/
static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
{
struct save_area *sa;
void *ptr_start = ptr;
int i;
ptr = nt_prpsinfo(ptr);
for (i = 0; i < dump_save_areas.count; i++) {
sa = dump_save_areas.areas[i];
if (sa->pref_reg == 0)
continue;
ptr = fill_cpu_elf_notes(ptr, sa);
}
ptr = nt_vmcoreinfo(ptr);
memset(phdr, 0, sizeof(*phdr));
phdr->p_type = PT_NOTE;
phdr->p_offset = notes_offset;
phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
phdr->p_memsz = phdr->p_filesz;
return ptr;
}
/*
* Create ELF core header (new kernel)
*/
int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
{
Elf64_Phdr *phdr_notes, *phdr_loads;
int mem_chunk_cnt;
void *ptr, *hdr;
u32 alloc_size;
u64 hdr_off;
/* If we are not in kdump or zfcpdump mode return */
if (!OLDMEM_BASE && ipl_info.type != IPL_TYPE_FCP_DUMP)
return 0;
/* If elfcorehdr= has been passed via cmdline, we use that one */
if (elfcorehdr_addr != ELFCORE_ADDR_MAX)
return 0;
/* If we cannot get HSA size for zfcpdump return error */
if (ipl_info.type == IPL_TYPE_FCP_DUMP && !sclp_get_hsa_size())
return -ENODEV;
mem_chunk_cnt = get_mem_chunk_cnt();
alloc_size = 0x1000 + get_cpu_cnt() * 0x300 +
mem_chunk_cnt * sizeof(Elf64_Phdr);
hdr = kzalloc_panic(alloc_size);
/* Init elf header */
ptr = ehdr_init(hdr, mem_chunk_cnt);
/* Init program headers */
phdr_notes = ptr;
ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
phdr_loads = ptr;
ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
/* Init notes */
hdr_off = PTR_DIFF(ptr, hdr);
ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
/* Init loads */
hdr_off = PTR_DIFF(ptr, hdr);
loads_init(phdr_loads, hdr_off);
*addr = (unsigned long long) hdr;
elfcorehdr_newmem = hdr;
*size = (unsigned long long) hdr_off;
BUG_ON(elfcorehdr_size > alloc_size);
return 0;
}
/*
* Free ELF core header (new kernel)
*/
void elfcorehdr_free(unsigned long long addr)
{
if (!elfcorehdr_newmem)
return;
kfree((void *)(unsigned long)addr);
}
/*
* Read from ELF header
*/
ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
{
void *src = (void *)(unsigned long)*ppos;
src = elfcorehdr_newmem ? src : src - OLDMEM_BASE;
memcpy(buf, src, count);
*ppos += count;
return count;
}
/*
* Read from ELF notes data
*/
ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
{
void *src = (void *)(unsigned long)*ppos;
int rc;
if (elfcorehdr_newmem) {
memcpy(buf, src, count);
} else {
rc = copy_from_oldmem(buf, src, count);
if (rc)
return rc;
}
*ppos += count;
return count;
}