diff options
author | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-09 10:03:44 -0800 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-09 10:03:44 -0800 |
commit | 6150c32589d1976ca8a5c987df951088c05a7542 (patch) | |
tree | 94073696576323ff966e365d8c47b8ecd8372f97 /arch/powerpc/kernel/crash_dump.c | |
parent | 44637a12f80b80157d9c1bc5b7d6ef09c9e05713 (diff) | |
parent | be42d5fa3772241b8ecebd443f1fb36247959c54 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc-merge
Diffstat (limited to 'arch/powerpc/kernel/crash_dump.c')
-rw-r--r-- | arch/powerpc/kernel/crash_dump.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c new file mode 100644 index 00000000000..87effa3f21a --- /dev/null +++ b/arch/powerpc/kernel/crash_dump.c @@ -0,0 +1,109 @@ +/* + * Routines for doing kexec-based kdump. + * + * Copyright (C) 2005, IBM Corp. + * + * Created by: Michael Ellerman + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + +#undef DEBUG + +#include <linux/crash_dump.h> +#include <linux/bootmem.h> +#include <asm/kdump.h> +#include <asm/lmb.h> +#include <asm/firmware.h> +#include <asm/uaccess.h> + +#ifdef DEBUG +#include <asm/udbg.h> +#define DBG(fmt...) udbg_printf(fmt) +#else +#define DBG(fmt...) +#endif + +static void __init create_trampoline(unsigned long addr) +{ + /* The maximum range of a single instruction branch, is the current + * instruction's address + (32 MB - 4) bytes. For the trampoline we + * need to branch to current address + 32 MB. So we insert a nop at + * the trampoline address, then the next instruction (+ 4 bytes) + * does a branch to (32 MB - 4). The net effect is that when we + * branch to "addr" we jump to ("addr" + 32 MB). Although it requires + * two instructions it doesn't require any registers. + */ + create_instruction(addr, 0x60000000); /* nop */ + create_branch(addr + 4, addr + PHYSICAL_START, 0); +} + +void __init kdump_setup(void) +{ + unsigned long i; + + DBG(" -> kdump_setup()\n"); + + for (i = KDUMP_TRAMPOLINE_START; i < KDUMP_TRAMPOLINE_END; i += 8) { + create_trampoline(i); + } + + create_trampoline(__pa(system_reset_fwnmi) - PHYSICAL_START); + create_trampoline(__pa(machine_check_fwnmi) - PHYSICAL_START); + + DBG(" <- kdump_setup()\n"); +} + +static int __init parse_elfcorehdr(char *p) +{ + if (p) + elfcorehdr_addr = memparse(p, &p); + + return 0; +} +__setup("elfcorehdr=", parse_elfcorehdr); + +static int __init parse_savemaxmem(char *p) +{ + if (p) + saved_max_pfn = (memparse(p, &p) >> PAGE_SHIFT) - 1; + + return 0; +} +__setup("savemaxmem=", parse_savemaxmem); + +/* + * copy_oldmem_page - copy one page from "oldmem" + * @pfn: page frame number to be copied + * @buf: target memory address for the copy; this can be in kernel address + * space or user address space (see @userbuf) + * @csize: number of bytes to copy + * @offset: offset in bytes into the page (based on pfn) to begin the copy + * @userbuf: if set, @buf is in user address space, use copy_to_user(), + * otherwise @buf is in kernel address space, use memcpy(). + * + * Copy a page from "oldmem". For this page, there is no pte mapped + * in the current kernel. We stitch up a pte, similar to kmap_atomic. + */ +ssize_t copy_oldmem_page(unsigned long pfn, char *buf, + size_t csize, unsigned long offset, int userbuf) +{ + void *vaddr; + + if (!csize) + return 0; + + vaddr = __ioremap(pfn << PAGE_SHIFT, PAGE_SIZE, 0); + + if (userbuf) { + if (copy_to_user((char __user *)buf, (vaddr + offset), csize)) { + iounmap(vaddr); + return -EFAULT; + } + } else + memcpy(buf, (vaddr + offset), csize); + + iounmap(vaddr); + return csize; +} |