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alistair23-linux/arch/m32r/kernel/head.S
Tim Abbott 743486dff1 m32r: Move the spi_stack_top and spu_stack_top into .init.data section. 
Since these get squashed into the .data output section by the m32r
linker script, it seems likely that they don't need their own input
sections.

At Hirokazu Takata's suggestion, we place these structures in
.init.data rather than just placing them in .data (since they are only
used at init time).

This patch is preparation for cleaning up the m32r architecture to use
the new macros in vmlinux.lds.h; if these sections are indeed not
needed, then we can use the RW_DATA_SECTION macro for m32r and save a
bunch of redundant code.

Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
2009-09-23 00:29:40 +09:00

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/*
* linux/arch/m32r/kernel/head.S
*
* M32R startup code.
*
* Copyright (c) 2001, 2002 Hiroyuki Kondo, Hirokazu Takata,
* Hitoshi Yamamoto
*/
#include <linux/init.h>
__INIT
__INITDATA
.text
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/assembler.h>
#include <asm/m32r.h>
#include <asm/mmu_context.h>
/*
* References to members of the boot_cpu_data structure.
*/
__HEAD
.global start_kernel
.global __bss_start
.global _end
ENTRY(stext)
ENTRY(_stext)
/* Setup up the stack pointer */
LDIMM (r0, spi_stack_top)
LDIMM (r1, spu_stack_top)
mvtc r0, spi
mvtc r1, spu
/* Initilalize PSW */
ldi r0, #0x0000 /* use SPI, disable EI */
mvtc r0, psw
/* Set up the stack pointer */
LDIMM (r0, stack_start)
ld r0, @r0
mvtc r0, spi
/*
* Clear BSS first so that there are no surprises...
*/
#ifdef CONFIG_ISA_DUAL_ISSUE
LDIMM (r2, __bss_start)
LDIMM (r3, _end)
sub r3, r2 ; BSS size in bytes
; R4 = BSS size in longwords (rounded down)
mv r4, r3 || ldi r1, #0
srli r4, #4 || addi r2, #-4
beqz r4, .Lendloop1
.Lloop1:
#ifndef CONFIG_CHIP_M32310
; Touch memory for the no-write-allocating cache.
ld r0, @(4,r2)
#endif
st r1, @+r2 || addi r4, #-1
st r1, @+r2
st r1, @+r2
st r1, @+r2 || cmpeq r1, r4 ; R4 = 0?
bnc .Lloop1
.Lendloop1:
and3 r4, r3, #15
addi r2, #4
beqz r4, .Lendloop2
.Lloop2:
stb r1, @r2 || addi r4, #-1
addi r2, #1
bnez r4, .Lloop2
.Lendloop2:
#else /* not CONFIG_ISA_DUAL_ISSUE */
LDIMM (r2, __bss_start)
LDIMM (r3, _end)
sub r3, r2 ; BSS size in bytes
mv r4, r3
srli r4, #2 ; R4 = BSS size in longwords (rounded down)
ldi r1, #0 ; clear R1 for longwords store
addi r2, #-4 ; account for pre-inc store
beqz r4, .Lendloop1 ; any more to go?
.Lloop1:
st r1, @+r2 ; yep, zero out another longword
addi r4, #-1 ; decrement count
bnez r4, .Lloop1 ; go do some more
.Lendloop1:
and3 r4, r3, #3 ; get no. of remaining BSS bytes to clear
addi r2, #4 ; account for pre-inc store
beqz r4, .Lendloop2 ; any more to go?
.Lloop2:
stb r1, @r2 ; yep, zero out another byte
addi r2, #1 ; bump address
addi r4, #-1 ; decrement count
bnez r4, .Lloop2 ; go do some more
.Lendloop2:
#endif /* not CONFIG_ISA_DUAL_ISSUE */
#if 0 /* M32R_FIXME */
/*
* Copy data segment from ROM to RAM.
*/
.global ROM_D, TOP_DATA, END_DATA
LDIMM (r1, ROM_D)
LDIMM (r2, TOP_DATA)
LDIMM (r3, END_DATA)
addi r2, #-4
addi r3, #-4
loop1:
ld r0, @r1+
st r0, @+r2
cmp r2, r3
bc loop1
#endif /* 0 */
/* Jump to kernel */
LDIMM (r2, start_kernel)
jl r2
.fillinsn
1:
bra 1b ; main should never return here, but
; just in case, we know what happens.
#ifdef CONFIG_SMP
/*
* AP startup routine
*/
.global eit_vector
ENTRY(startup_AP)
;; setup EVB
LDIMM (r4, eit_vector)
mvtc r4, cr5
;; enable MMU
LDIMM (r2, init_tlb)
jl r2
seth r4, #high(MATM)
or3 r4, r4, #low(MATM)
ldi r5, #0x01
st r5, @r4 ; Set MATM Reg(T bit ON)
ld r6, @r4 ; MATM Check
LDIMM (r5, 1f)
jmp r5 ; enable MMU
nop
.fillinsn
1:
;; ISN check
ld r6, @r4 ; MATM Check
seth r4, #high(M32R_ICU_ISTS_ADDR)
or3 r4, r4, #low(M32R_ICU_ISTS_ADDR)
ld r5, @r4 ; Read ISTSi reg.
mv r6, r5
slli r5, #13 ; PIML check
srli r5, #13 ;
seth r4, #high(M32R_ICU_IMASK_ADDR)
or3 r4, r4, #low(M32R_ICU_IMASK_ADDR)
st r5, @r4 ; Write IMASKi reg.
slli r6, #4 ; ISN check
srli r6, #26 ;
seth r4, #high(M32R_IRQ_IPI5)
or3 r4, r4, #low(M32R_IRQ_IPI5)
bne r4, r6, 2f ; if (ISN != CPU_BOOT_IPI) goto sleep;
;; check cpu_bootout_map and set cpu_bootin_map
LDIMM (r4, cpu_bootout_map)
ld r4, @r4
seth r5, #high(M32R_CPUID_PORTL)
or3 r5, r5, #low(M32R_CPUID_PORTL)
ld r5, @r5
ldi r6, #1
sll r6, r5
and r4, r6
beqz r4, 2f
LDIMM (r4, cpu_bootin_map)
ld r5, @r4
or r5, r6
st r6, @r4
;; clear PSW
ldi r4, #0
mvtc r4, psw
;; setup SPI
LDIMM (r4, stack_start)
ld r4, @r4
mvtc r4, spi
;; setup BPC (start_secondary)
LDIMM (r4, start_secondary)
mvtc r4, bpc
rte ; goto startup_secondary
nop
nop
.fillinsn
2:
;; disable MMU
seth r4, #high(MATM)
or3 r4, r4, #low(MATM)
ldi r5, #0
st r5, @r4 ; Set MATM Reg(T bit OFF)
ld r6, @r4 ; MATM Check
LDIMM (r4, 3f)
seth r5, #high(__PAGE_OFFSET)
or3 r5, r5, #low(__PAGE_OFFSET)
not r5, r5
and r4, r5
jmp r4 ; disable MMU
nop
.fillinsn
3:
;; SLEEP and wait IPI
LDIMM (r4, AP_loop)
seth r5, #high(__PAGE_OFFSET)
or3 r5, r5, #low(__PAGE_OFFSET)
not r5, r5
and r4, r5
jmp r4
nop
nop
#endif /* CONFIG_SMP */
.text
ENTRY(stack_start)
.long init_thread_union+8192
.long __KERNEL_DS
/*
* This is initialized to create a identity-mapping at 0-4M (for bootup
* purposes) and another mapping of the 0-4M area at virtual address
* PAGE_OFFSET.
*/
.text
#define MOUNT_ROOT_RDONLY 1
#define RAMDISK_FLAGS 0 ; 1024KB
#define ORIG_ROOT_DEV 0x0100 ; /dev/ram0 (major:01, minor:00)
#define LOADER_TYPE 1 ; (??? - non-zero value seems
; to be needed to boot from initrd)
#define COMMAND_LINE ""
.section .empty_zero_page, "aw"
ENTRY(empty_zero_page)
.long MOUNT_ROOT_RDONLY /* offset: +0x00 */
.long RAMDISK_FLAGS
.long ORIG_ROOT_DEV
.long LOADER_TYPE
.long 0 /* INITRD_START */ /* +0x10 */
.long 0 /* INITRD_SIZE */
.long 0 /* CPU_CLOCK */
.long 0 /* BUS_CLOCK */
.long 0 /* TIMER_DIVIDE */ /* +0x20 */
.balign 256,0
.asciz COMMAND_LINE
.byte 0
.balign 4096,0,4096
/*------------------------------------------------------------------------
* Stack area
*/
.section .init.data, "aw"
ALIGN
.global spi_stack_top
.zero 1024
spi_stack_top:
.section .init.data, "aw"
ALIGN
.global spu_stack_top
.zero 1024
spu_stack_top:
.end
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