m68k: Add kexec support

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
This commit is contained in:
Geert Uytterhoeven 2013-08-20 22:51:47 +02:00
parent 6cf30b3547
commit 7d5f5fa276
7 changed files with 269 additions and 0 deletions

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@ -87,6 +87,23 @@ config MMU_SUN3
bool
depends on MMU && !MMU_MOTOROLA && !MMU_COLDFIRE
config KEXEC
bool "kexec system call"
depends on M68KCLASSIC
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 independent of the system firmware. And like a reboot
you can start any kernel with it, not just Linux.
The name comes from the similarity 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. As of this writing the exact hardware
interface is strongly in flux, so no good recommendation can be
made.
menu "Platform setup"
source arch/m68k/Kconfig.cpu

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@ -0,0 +1,29 @@
#ifndef _ASM_M68K_KEXEC_H
#define _ASM_M68K_KEXEC_H
#ifdef CONFIG_KEXEC
/* Maximum physical address we can use pages from */
#define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
/* Maximum address we can reach in physical address mode */
#define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
/* Maximum address we can use for the control code buffer */
#define KEXEC_CONTROL_MEMORY_LIMIT (-1UL)
#define KEXEC_CONTROL_PAGE_SIZE 4096
#define KEXEC_ARCH KEXEC_ARCH_68K
#ifndef __ASSEMBLY__
static inline void crash_setup_regs(struct pt_regs *newregs,
struct pt_regs *oldregs)
{
/* Dummy implementation for now */
}
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_KEXEC */
#endif /* _ASM_M68K_KEXEC_H */

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@ -22,3 +22,5 @@ obj-$(CONFIG_PCI) += pcibios.o
obj-$(CONFIG_HAS_DMA) += dma.o
obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o

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@ -98,6 +98,9 @@ int main(void)
DEFINE(CIABBASE, &ciab);
DEFINE(C_PRA, offsetof(struct CIA, pra));
DEFINE(ZTWOBASE, zTwoBase);
/* enum m68k_fixup_type */
DEFINE(M68K_FIXUP_MEMOFFSET, m68k_fixup_memoffset);
#endif
return 0;

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@ -0,0 +1,58 @@
/*
* machine_kexec.c - handle transition of Linux booting another kernel
*/
#include <linux/compiler.h>
#include <linux/kexec.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <asm/cacheflush.h>
#include <asm/page.h>
#include <asm/setup.h>
extern const unsigned char relocate_new_kernel[];
extern const size_t relocate_new_kernel_size;
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)
{
}
typedef void (*relocate_kernel_t)(unsigned long ptr,
unsigned long start,
unsigned long cpu_mmu_flags) __noreturn;
void machine_kexec(struct kimage *image)
{
void *reboot_code_buffer;
unsigned long cpu_mmu_flags;
reboot_code_buffer = page_address(image->control_code_page);
memcpy(reboot_code_buffer, relocate_new_kernel,
relocate_new_kernel_size);
/*
* we do not want to be bothered.
*/
local_irq_disable();
pr_info("Will call new kernel at 0x%08lx. Bye...\n", image->start);
__flush_cache_all();
cpu_mmu_flags = m68k_cputype | m68k_mmutype << 8;
((relocate_kernel_t) reboot_code_buffer)(image->head & PAGE_MASK,
image->start,
cpu_mmu_flags);
}

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@ -0,0 +1,159 @@
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/page.h>
#include <asm/setup.h>
#define MMU_BASE 8 /* MMU flags base in cpu_mmu_flags */
.text
ENTRY(relocate_new_kernel)
movel %sp@(4),%a0 /* a0 = ptr */
movel %sp@(8),%a1 /* a1 = start */
movel %sp@(12),%d1 /* d1 = cpu_mmu_flags */
movew #PAGE_MASK,%d2 /* d2 = PAGE_MASK */
/* Disable MMU */
btst #MMU_BASE + MMUB_68851,%d1
jeq 3f
1: /* 68851 or 68030 */
lea %pc@(.Lcopy),%a4
2: addl #0x00000000,%a4 /* virt_to_phys() */
.section ".m68k_fixup","aw"
.long M68K_FIXUP_MEMOFFSET, 2b+2
.previous
.chip 68030
pmove %tc,%d0 /* Disable MMU */
bclr #7,%d0
pmove %d0,%tc
jmp %a4@ /* Jump to physical .Lcopy */
.chip 68k
3:
btst #MMU_BASE + MMUB_68030,%d1
jne 1b
btst #MMU_BASE + MMUB_68040,%d1
jeq 6f
4: /* 68040 or 68060 */
lea %pc@(.Lcont040),%a4
5: addl #0x00000000,%a4 /* virt_to_phys() */
.section ".m68k_fixup","aw"
.long M68K_FIXUP_MEMOFFSET, 5b+2
.previous
movel %a4,%d0
andl #0xff000000,%d0
orw #0xe020,%d0 /* Map 16 MiB, enable, cacheable */
.chip 68040
movec %d0,%itt0
movec %d0,%dtt0
.chip 68k
jmp %a4@ /* Jump to physical .Lcont040 */
.Lcont040:
moveq #0,%d0
.chip 68040
movec %d0,%tc /* Disable MMU */
movec %d0,%itt0
movec %d0,%itt1
movec %d0,%dtt0
movec %d0,%dtt1
.chip 68k
jra .Lcopy
6:
btst #MMU_BASE + MMUB_68060,%d1
jne 4b
.Lcopy:
movel %a0@+,%d0 /* d0 = entry = *ptr */
jeq .Lflush
btst #2,%d0 /* entry & IND_DONE? */
jne .Lflush
btst #1,%d0 /* entry & IND_INDIRECTION? */
jeq 1f
andw %d2,%d0
movel %d0,%a0 /* ptr = entry & PAGE_MASK */
jra .Lcopy
1:
btst #0,%d0 /* entry & IND_DESTINATION? */
jeq 2f
andw %d2,%d0
movel %d0,%a2 /* a2 = dst = entry & PAGE_MASK */
jra .Lcopy
2:
btst #3,%d0 /* entry & IND_SOURCE? */
jeq .Lcopy
andw %d2,%d0
movel %d0,%a3 /* a3 = src = entry & PAGE_MASK */
movew #PAGE_SIZE/32 - 1,%d0 /* d0 = PAGE_SIZE/32 - 1 */
3:
movel %a3@+,%a2@+ /* *dst++ = *src++ */
movel %a3@+,%a2@+ /* *dst++ = *src++ */
movel %a3@+,%a2@+ /* *dst++ = *src++ */
movel %a3@+,%a2@+ /* *dst++ = *src++ */
movel %a3@+,%a2@+ /* *dst++ = *src++ */
movel %a3@+,%a2@+ /* *dst++ = *src++ */
movel %a3@+,%a2@+ /* *dst++ = *src++ */
movel %a3@+,%a2@+ /* *dst++ = *src++ */
dbf %d0, 3b
jra .Lcopy
.Lflush:
/* Flush all caches */
btst #CPUB_68020,%d1
jeq 2f
1: /* 68020 or 68030 */
.chip 68030
movec %cacr,%d0
orw #0x808,%d0
movec %d0,%cacr
.chip 68k
jra .Lreincarnate
2:
btst #CPUB_68030,%d1
jne 1b
btst #CPUB_68040,%d1
jeq 4f
3: /* 68040 or 68060 */
.chip 68040
nop
cpusha %bc
nop
cinva %bc
nop
.chip 68k
jra .Lreincarnate
4:
btst #CPUB_68060,%d1
jne 3b
.Lreincarnate:
jmp %a1@
relocate_new_kernel_end:
ENTRY(relocate_new_kernel_size)
.long relocate_new_kernel_end - relocate_new_kernel

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@ -18,6 +18,7 @@
*/
#define KEXEC_ARCH_DEFAULT ( 0 << 16)
#define KEXEC_ARCH_386 ( 3 << 16)
#define KEXEC_ARCH_68K ( 4 << 16)
#define KEXEC_ARCH_X86_64 (62 << 16)
#define KEXEC_ARCH_PPC (20 << 16)
#define KEXEC_ARCH_PPC64 (21 << 16)