Commit 583bb86f authored by Nicolas Schichan's avatar Nicolas Schichan Committed by Ralf Baechle
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[MIPS] Add support for kexec

A tiny userland application loading the kernel and invoking kexec_load for 
mips is available here:

http://chac.le-poulpe.net/~nico/kexec/kexec-2006-10-18.tar.gz

Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent c2379230
......@@ -766,6 +766,23 @@ config TOSHIBA_RBTX4938
endchoice
config KEXEC
bool "Kexec system call (EXPERIMENTAL)"
depends on EXPERIMENTAL
help
kexec is a system call that implements the ability to shutdown your
current kernel, and to start another kernel. It is like a reboot
but it is indepedent of the system firmware. And like a reboot
you can start any kernel with it, not just Linux.
The name comes from the similiarity to the exec system call.
It is an ongoing process to be certain the hardware in a machine
is properly shutdown, so do not be surprised if this code does not
initially work for you. It may help to enable device hotplugging
support. As of this writing the exact hardware interface is
strongly in flux, so no good recommendation can be made.
source "arch/mips/ddb5xxx/Kconfig"
source "arch/mips/gt64120/ev64120/Kconfig"
source "arch/mips/jazz/Kconfig"
......
......@@ -67,6 +67,8 @@ obj-$(CONFIG_64BIT) += cpu-bugs64.o
obj-$(CONFIG_I8253) += i8253.o
obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o
CFLAGS_cpu-bugs64.o = $(shell if $(CC) $(CFLAGS) -Wa,-mdaddi -c -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
EXTRA_AFLAGS := $(CFLAGS)
/*
* machine_kexec.c for kexec
* Created by <nschichan@corp.free.fr> on Thu Oct 12 15:15:06 2006
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <linux/kexec.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <asm/cacheflush.h>
#include <asm/page.h>
const extern unsigned char relocate_new_kernel[];
const extern unsigned int relocate_new_kernel_size;
extern unsigned long kexec_start_address;
extern unsigned long kexec_indirection_page;
int
machine_kexec_prepare(struct kimage *kimage)
{
return 0;
}
void
machine_kexec_cleanup(struct kimage *kimage)
{
}
void
machine_shutdown(void)
{
}
void
machine_crash_shutdown(struct pt_regs *regs)
{
}
void
machine_kexec(struct kimage *image)
{
unsigned long reboot_code_buffer;
unsigned long entry;
unsigned long *ptr;
reboot_code_buffer =
(unsigned long)page_address(image->control_code_page);
kexec_start_address = image->start;
kexec_indirection_page = phys_to_virt(image->head & PAGE_MASK);
memcpy((void*)reboot_code_buffer, relocate_new_kernel,
relocate_new_kernel_size);
/*
* The generic kexec code builds a page list with physical
* addresses. they are directly accessible through KSEG0 (or
* CKSEG0 or XPHYS if on 64bit system), hence the
* pys_to_virt() call.
*/
for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
ptr = (entry & IND_INDIRECTION) ?
phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
*ptr & IND_DESTINATION)
*ptr = phys_to_virt(*ptr);
}
/*
* we do not want to be bothered.
*/
local_irq_disable();
flush_icache_range(reboot_code_buffer,
reboot_code_buffer + KEXEC_CONTROL_CODE_SIZE);
printk("Will call new kernel at %08x\n", image->start);
printk("Bye ...\n");
flush_cache_all();
((void (*)(void))reboot_code_buffer)();
}
/*
* relocate_kernel.S for kexec
* Created by <nschichan@corp.free.fr> on Thu Oct 12 17:49:57 2006
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/regdef.h>
#include <asm/page.h>
#include <asm/mipsregs.h>
#include <asm/stackframe.h>
#include <asm/addrspace.h>
.globl relocate_new_kernel
relocate_new_kernel:
PTR_L s0, kexec_indirection_page
PTR_L s1, kexec_start_address
process_entry:
PTR_L s2, (s0)
PTR_ADD s0, s0, SZREG
/* destination page */
and s3, s2, 0x1
beq s3, zero, 1f
and s4, s2, ~0x1 /* store destination addr in s4 */
move a0, s4
b process_entry
1:
/* indirection page, update s0 */
and s3, s2, 0x2
beq s3, zero, 1f
and s0, s2, ~0x2
b process_entry
1:
/* done page */
and s3, s2, 0x4
beq s3, zero, 1f
b done
1:
/* source page */
and s3, s2, 0x8
beq s3, zero, process_entry
and s2, s2, ~0x8
li s6, (1 << PAGE_SHIFT) / SZREG
copy_word:
/* copy page word by word */
REG_L s5, (s2)
REG_S s5, (s4)
INT_ADD s4, s4, SZREG
INT_ADD s2, s2, SZREG
INT_SUB s6, s6, 1
beq s6, zero, process_entry
b copy_word
b process_entry
done:
/* jump to kexec_start_address */
j s1
.globl kexec_start_address
kexec_start_address:
.long 0x0
.globl kexec_indirection_page
kexec_indirection_page:
.long 0x0
relocate_new_kernel_end:
.globl relocate_new_kernel_size
relocate_new_kernel_size:
.long relocate_new_kernel_end - relocate_new_kernel
......@@ -653,7 +653,7 @@ einval: li v0, -EINVAL
sys sys_move_pages 6
sys sys_set_robust_list 2
sys sys_get_robust_list 3 /* 4310 */
sys sys_ni_syscall 0
sys sys_kexec_load 4
sys sys_getcpu 3
sys sys_epoll_pwait 6
.endm
......
......@@ -468,6 +468,6 @@ sys_call_table:
PTR sys_move_pages
PTR sys_set_robust_list
PTR sys_get_robust_list
PTR sys_ni_syscall /* 5270 */
PTR sys_kexec_load /* 5270 */
PTR sys_getcpu
PTR sys_epoll_pwait
......@@ -394,6 +394,6 @@ EXPORT(sysn32_call_table)
PTR sys_move_pages
PTR compat_sys_set_robust_list
PTR compat_sys_get_robust_list
PTR sys_ni_syscall
PTR compat_sys_kexec_load
PTR sys_getcpu
PTR sys_epoll_pwait
......@@ -516,7 +516,7 @@ sys_call_table:
PTR compat_sys_move_pages
PTR compat_sys_set_robust_list
PTR compat_sys_get_robust_list /* 4310 */
PTR sys_ni_syscall
PTR compat_sys_kexec_load
PTR sys_getcpu
PTR sys_epoll_pwait
.size sys_call_table,.-sys_call_table
/*
* kexec.h for kexec
* Created by <nschichan@corp.free.fr> on Thu Oct 12 14:59:34 2006
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#ifndef _MIPS_KEXEC
# define _MIPS_KEXEC
/* Maximum physical address we can use pages from */
#define KEXEC_SOURCE_MEMORY_LIMIT (0x20000000)
/* Maximum address we can reach in physical address mode */
#define KEXEC_DESTINATION_MEMORY_LIMIT (0x20000000)
/* Maximum address we can use for the control code buffer */
#define KEXEC_CONTROL_MEMORY_LIMIT (0x20000000)
#define KEXEC_CONTROL_CODE_SIZE 4096
/* The native architecture */
#define KEXEC_ARCH KEXEC_ARCH_MIPS
#define MAX_NOTE_BYTES 1024
static inline void crash_setup_regs(struct pt_regs *newregs,
struct pt_regs *oldregs)
{
/* Dummy implementation for now */
}
#endif /* !_MIPS_KEXEC */
......@@ -122,6 +122,8 @@ extern struct kimage *kexec_crash_image;
#define KEXEC_ARCH_IA_64 (50 << 16)
#define KEXEC_ARCH_S390 (22 << 16)
#define KEXEC_ARCH_SH (42 << 16)
#define KEXEC_ARCH_MIPS_LE (10 << 16)
#define KEXEC_ARCH_MIPS ( 8 << 16)
#define KEXEC_FLAGS (KEXEC_ON_CRASH) /* List of defined/legal kexec flags */
......
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