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sh: Tidy up the sh bios VBR handling.

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This moves the VBR handling out of the main trap handling code and in to
the sh-bios helper code. A couple of accessors are added in order to
permit other kernel code to get at the VBR value for state save/restore
paths.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Paul Mundt 2010-01-12 14:50:43 +09:00
parent ee2760ea58
commit 191d0d24b6
4 changed files with 55 additions and 33 deletions
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14
arch/sh/include/asm/sh_bios.h
View File

@ -1,13 +1,13 @@
#ifndef __ASM_SH_BIOS_H
#define __ASM_SH_BIOS_H
#ifdef CONFIG_SH_STANDARD_BIOS
/*
* Copyright (C) 2000 Greg Banks, Mitch Davis
* C API to interface to the standard LinuxSH BIOS
* usually from within the early stages of kernel boot.
*/
extern void sh_bios_console_write(const char *buf, unsigned int len);
extern void sh_bios_char_out(char ch);
extern void sh_bios_gdb_detach(void);
@ -15,4 +15,14 @@ extern void sh_bios_gdb_detach(void);
extern void sh_bios_get_node_addr(unsigned char *node_addr);
extern void sh_bios_shutdown(unsigned int how);
extern void sh_bios_vbr_init(void);
extern void sh_bios_vbr_reload(void);
#else
static inline void sh_bios_vbr_init(void) { }
static inline void sh_bios_vbr_reload(void) { }
#endif /* CONFIG_SH_STANDARD_BIOS */
#endif /* __ASM_SH_BIOS_H */

8
arch/sh/kernel/machine_kexec.c
View File

@ -21,6 +21,7 @@
#include <asm/mmu_context.h>
#include <asm/io.h>
#include <asm/cacheflush.h>
#include <asm/sh_bios.h>
typedef void (*relocate_new_kernel_t)(unsigned long indirection_page,
unsigned long reboot_code_buffer,
@ -28,7 +29,6 @@ typedef void (*relocate_new_kernel_t)(unsigned long indirection_page,
extern const unsigned char relocate_new_kernel[];
extern const unsigned int relocate_new_kernel_size;
extern void *gdb_vbr_vector;
extern void *vbr_base;
void machine_shutdown(void)
@ -117,11 +117,7 @@ void machine_kexec(struct kimage *image)
kexec_info(image);
flush_cache_all();
#if defined(CONFIG_SH_STANDARD_BIOS)
asm volatile("ldc %0, vbr" :
: "r" (((unsigned long) gdb_vbr_vector) - 0x100)
: "memory");
#endif
sh_bios_vbr_reload();
/* now call it */
rnk = (relocate_new_kernel_t) reboot_code_buffer;

37
arch/sh/kernel/sh_bios.c
View File

@ -55,3 +55,40 @@ void sh_bios_shutdown(unsigned int how)
{
sh_bios_call(BIOS_CALL_SHUTDOWN, how, 0, 0, 0);
}
void *gdb_vbr_vector = NULL;
/*
* Read the old value of the VBR register to initialise the vector
* through which debug and BIOS traps are delegated by the Linux trap
* handler.
*/
void sh_bios_vbr_init(void)
{
unsigned long vbr;
if (unlikely(gdb_vbr_vector))
return;
__asm__ __volatile__ ("stc vbr, %0" : "=r" (vbr));
gdb_vbr_vector = (void *)(vbr + 0x100);
printk(KERN_NOTICE "Setting GDB trap vector to %p\n", gdb_vbr_vector);
}
/**
* sh_bios_vbr_reload - Re-load the system VBR from the BIOS vector.
*
* This can be used by save/restore code to reinitialize the system VBR
* from the fixed BIOS VBR. A no-op if no BIOS VBR is known.
*/
void sh_bios_vbr_reload(void)
{
if (gdb_vbr_vector)
__asm__ __volatile__ (
"ldc %0, vbr"
:
: "r" (((unsigned long) gdb_vbr_vector) - 0x100)
: "memory"
);
}

29
arch/sh/kernel/traps_32.c
View File

@ -31,6 +31,7 @@
#include <asm/uaccess.h>
#include <asm/fpu.h>
#include <asm/kprobes.h>
#include <asm/sh_bios.h>
#ifdef CONFIG_CPU_SH2
# define TRAP_RESERVED_INST 4
@ -876,35 +877,10 @@ asmlinkage void do_exception_error(unsigned long r4, unsigned long r5,
die_if_kernel("exception", regs, ex);
}
#if defined(CONFIG_SH_STANDARD_BIOS)
void *gdb_vbr_vector;
static inline void __init gdb_vbr_init(void)
{
register unsigned long vbr;
/*
* Read the old value of the VBR register to initialise
* the vector through which debug and BIOS traps are
* delegated by the Linux trap handler.
*/
asm volatile("stc vbr, %0" : "=r" (vbr));
gdb_vbr_vector = (void *)(vbr + 0x100);
printk("Setting GDB trap vector to 0x%08lx\n",
(unsigned long)gdb_vbr_vector);
}
#endif
void __cpuinit per_cpu_trap_init(void)
{
extern void *vbr_base;
#ifdef CONFIG_SH_STANDARD_BIOS
if (raw_smp_processor_id() == 0)
gdb_vbr_init();
#endif
/* NOTE: The VBR value should be at P1
(or P2, virtural "fixed" address space).
It's definitely should not in physical address. */
@ -959,6 +935,9 @@ void __init trap_init(void)
set_exception_table_vec(TRAP_UBC, break_point_trap);
#endif
/* Save off the BIOS VBR, if there is one */
sh_bios_vbr_init();
/* Setup VBR for boot cpu */
per_cpu_trap_init();
}