473104134b
We need to know the base address of the kdump kernel even when we're not a kdump kernel, so add a #define for it. Move the logic that sets the kdump kernelbase into kdump.h instead of page.h. Rename kdump_setup() to setup_kdump_trampoline() to make it clearer what it's doing, and add an empty definition for the !CRASH_DUMP case to avoid a Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
116 lines
2.9 KiB
C
116 lines
2.9 KiB
C
/*
|
|
* 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
|
|
|
|
void reserve_kdump_trampoline(void)
|
|
{
|
|
lmb_reserve(0, KDUMP_RESERVE_LIMIT);
|
|
}
|
|
|
|
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 setup_kdump_trampoline(void)
|
|
{
|
|
unsigned long i;
|
|
|
|
DBG(" -> setup_kdump_trampoline()\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(" <- setup_kdump_trampoline()\n");
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_VMCORE
|
|
static int __init parse_elfcorehdr(char *p)
|
|
{
|
|
if (p)
|
|
elfcorehdr_addr = memparse(p, &p);
|
|
|
|
return 1;
|
|
}
|
|
__setup("elfcorehdr=", parse_elfcorehdr);
|
|
#endif
|
|
|
|
static int __init parse_savemaxmem(char *p)
|
|
{
|
|
if (p)
|
|
saved_max_pfn = (memparse(p, &p) >> PAGE_SHIFT) - 1;
|
|
|
|
return 1;
|
|
}
|
|
__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;
|
|
}
|