150 lines
4.0 KiB
C
150 lines
4.0 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 <linux/io.h>
|
|
#include <linux/memblock.h>
|
|
#include <asm/code-patching.h>
|
|
#include <asm/kdump.h>
|
|
#include <asm/prom.h>
|
|
#include <asm/firmware.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/rtas.h>
|
|
|
|
#ifdef DEBUG
|
|
#include <asm/udbg.h>
|
|
#define DBG(fmt...) udbg_printf(fmt)
|
|
#else
|
|
#define DBG(fmt...)
|
|
#endif
|
|
|
|
#ifndef CONFIG_NONSTATIC_KERNEL
|
|
void __init reserve_kdump_trampoline(void)
|
|
{
|
|
memblock_reserve(0, KDUMP_RESERVE_LIMIT);
|
|
}
|
|
|
|
static void __init create_trampoline(unsigned long addr)
|
|
{
|
|
unsigned int *p = (unsigned int *)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.
|
|
*/
|
|
patch_instruction(p, PPC_INST_NOP);
|
|
patch_branch(++p, 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);
|
|
}
|
|
|
|
#ifdef CONFIG_PPC_PSERIES
|
|
create_trampoline(__pa(system_reset_fwnmi) - PHYSICAL_START);
|
|
create_trampoline(__pa(machine_check_fwnmi) - PHYSICAL_START);
|
|
#endif /* CONFIG_PPC_PSERIES */
|
|
|
|
DBG(" <- setup_kdump_trampoline()\n");
|
|
}
|
|
#endif /* CONFIG_NONSTATIC_KERNEL */
|
|
|
|
static size_t copy_oldmem_vaddr(void *vaddr, char *buf, size_t csize,
|
|
unsigned long offset, int userbuf)
|
|
{
|
|
if (userbuf) {
|
|
if (copy_to_user((char __user *)buf, (vaddr + offset), csize))
|
|
return -EFAULT;
|
|
} else
|
|
memcpy(buf, (vaddr + offset), csize);
|
|
|
|
return csize;
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
phys_addr_t paddr;
|
|
|
|
if (!csize)
|
|
return 0;
|
|
|
|
csize = min_t(size_t, csize, PAGE_SIZE);
|
|
paddr = pfn << PAGE_SHIFT;
|
|
|
|
if (memblock_is_region_memory(paddr, csize)) {
|
|
vaddr = __va(paddr);
|
|
csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf);
|
|
} else {
|
|
vaddr = __ioremap(paddr, PAGE_SIZE, 0);
|
|
csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf);
|
|
iounmap(vaddr);
|
|
}
|
|
|
|
return csize;
|
|
}
|
|
|
|
#ifdef CONFIG_PPC_RTAS
|
|
/*
|
|
* The crashkernel region will almost always overlap the RTAS region, so
|
|
* we have to be careful when shrinking the crashkernel region.
|
|
*/
|
|
void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
|
|
{
|
|
unsigned long addr;
|
|
const __be32 *basep, *sizep;
|
|
unsigned int rtas_start = 0, rtas_end = 0;
|
|
|
|
basep = of_get_property(rtas.dev, "linux,rtas-base", NULL);
|
|
sizep = of_get_property(rtas.dev, "rtas-size", NULL);
|
|
|
|
if (basep && sizep) {
|
|
rtas_start = be32_to_cpup(basep);
|
|
rtas_end = rtas_start + be32_to_cpup(sizep);
|
|
}
|
|
|
|
for (addr = begin; addr < end; addr += PAGE_SIZE) {
|
|
/* Does this page overlap with the RTAS region? */
|
|
if (addr <= rtas_end && ((addr + PAGE_SIZE) > rtas_start))
|
|
continue;
|
|
|
|
free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
|
|
}
|
|
}
|
|
#endif
|