projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 0cc4746c ME |
1 | /* |
| 2 | * Routines for doing kexec-based kdump. | |
| 3 | * | |
| 4 | * Copyright (C) 2005, IBM Corp. | |
| 5 | * | |
| 6 | * Created by: Michael Ellerman | |
| 7 | * | |
| 8 | * This source code is licensed under the GNU General Public License, | |
| 9 | * Version 2. See the file COPYING for more details. | |
| 10 | */ | |
| 11 | ||
| 12 | #undef DEBUG | |
| 13 | ||
| 14 | #include <asm/kdump.h> | |
| 15 | #include <asm/lmb.h> | |
| 16 | #include <asm/firmware.h> | |
| 17 | ||
| 18 | #ifdef DEBUG | |
| 19 | #include <asm/udbg.h> | |
| 20 | #define DBG(fmt...) udbg_printf(fmt) | |
| 21 | #else | |
| 22 | #define DBG(fmt...) | |
| 23 | #endif | |
| 24 | ||
| 25 | static void __init create_trampoline(unsigned long addr) | |
| 26 | { | |
| 27 | /* The maximum range of a single instruction branch, is the current | |
| 28 | * instruction's address + (32 MB - 4) bytes. For the trampoline we | |
| 29 | * need to branch to current address + 32 MB. So we insert a nop at | |
| 30 | * the trampoline address, then the next instruction (+ 4 bytes) | |
| 31 | * does a branch to (32 MB - 4). The net effect is that when we | |
| 32 | * branch to "addr" we jump to ("addr" + 32 MB). Although it requires | |
| 33 | * two instructions it doesn't require any registers. | |
| 34 | */ | |
| 35 | create_instruction(addr, 0x60000000); /* nop */ | |
| 36 | create_branch(addr + 4, addr + PHYSICAL_START, 0); | |
| 37 | } | |
| 38 | ||
| 39 | void __init kdump_setup(void) | |
| 40 | { | |
| 41 | unsigned long i; | |
| 42 | ||
| 43 | DBG(" -> kdump_setup()\n"); | |
| 44 | ||
| 45 | for (i = KDUMP_TRAMPOLINE_START; i < KDUMP_TRAMPOLINE_END; i += 8) { | |
| 46 | create_trampoline(i); | |
| 47 | } | |
| 48 | ||
| 49 | create_trampoline(__pa(system_reset_fwnmi) - PHYSICAL_START); | |
| 50 | create_trampoline(__pa(machine_check_fwnmi) - PHYSICAL_START); | |
| 51 | ||
| 52 | DBG(" <- kdump_setup()\n"); | |
| 53 | } |