linux/arch/powerpc/kernel/crash_dump.c
Suzuki Poulose 0f890c8d20 powerpc: Rename mapping based RELOCATABLE to DYNAMIC_MEMSTART for BookE
The current implementation of CONFIG_RELOCATABLE in BookE is based
on mapping the page aligned kernel load address to KERNELBASE. This
approach however is not enough for platforms, where the TLB page size
is large (e.g, 256M on 44x). So we are renaming the RELOCATABLE used
currently in BookE to DYNAMIC_MEMSTART to reflect the actual method.

The CONFIG_RELOCATABLE for PPC32(BookE) based on processing of the
dynamic relocations will be introduced in the later in the patch series.

This change would allow the use of the old method of RELOCATABLE for
platforms which can afford to enforce the page alignment (platforms with
smaller TLB size).

Changes since v3:

* Introduced a new config, NONSTATIC_KERNEL, to denote a kernel which is
  either a RELOCATABLE or DYNAMIC_MEMSTART(Suggested by: Josh Boyer)

Suggested-by: Scott Wood <scottwood@freescale.com>
Tested-by: Scott Wood <scottwood@freescale.com>

Signed-off-by: Suzuki K. Poulose <suzuki@in.ibm.com>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linux ppc dev <linuxppc-dev@lists.ozlabs.org>
Signed-off-by: Josh Boyer <jwboyer@gmail.com>
2011-12-20 10:20:19 -05:00

160 lines
4.2 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/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 int __init parse_savemaxmem(char *p)
{
if (p)
saved_max_pfn = (memparse(p, &p) >> PAGE_SHIFT) - 1;
return 1;
}
__setup("savemaxmem=", parse_savemaxmem);
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;
if (!csize)
return 0;
csize = min_t(size_t, csize, PAGE_SIZE);
if ((min_low_pfn < pfn) && (pfn < max_pfn)) {
vaddr = __va(pfn << PAGE_SHIFT);
csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf);
} else {
vaddr = __ioremap(pfn << PAGE_SHIFT, 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 u32 *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 = *basep;
rtas_end = *basep + *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;
ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT));
init_page_count(pfn_to_page(addr >> PAGE_SHIFT));
free_page((unsigned long)__va(addr));
totalram_pages++;
}
}
#endif