diff options
Diffstat (limited to 'arch/powerpc/kernel/crash_dump.c')
| -rw-r--r-- | arch/powerpc/kernel/crash_dump.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c new file mode 100644 index 000000000000..63919bcfc9fe --- /dev/null +++ b/arch/powerpc/kernel/crash_dump.c @@ -0,0 +1,53 @@ +/* + * 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 <asm/kdump.h> +#include <asm/lmb.h> +#include <asm/firmware.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"); +} |