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[PATCH] ARM SMP: reallocate main IRQ handler code registers

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By changing r9 -> r8 and r8 to 'tsk' (r9) we are able to remove
one instruction from the preempt path.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
This commit is contained in:
Russell King 2005-05-21 18:15:45 +01:00 committed by Russell King
parent 187a51ad11
commit 706fdd9faa
1 changed files with 16 additions and 19 deletions
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35
arch/arm/kernel/entry-armv.S
View file

@ -144,20 +144,20 @@ __dabt_svc:
__irq_svc:
svc_entry irq
#ifdef CONFIG_PREEMPT
get_thread_info r8
ldr r9, [r8, #TI_PREEMPT] @ get preempt count
add r7, r9, #1 @ increment it
str r7, [r8, #TI_PREEMPT]
get_thread_info tsk
ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
add r7, r8, #1 @ increment it
str r7, [tsk, #TI_PREEMPT]
#endif
irq_handler
#ifdef CONFIG_PREEMPT
ldr r0, [r8, #TI_FLAGS] @ get flags
ldr r0, [tsk, #TI_FLAGS] @ get flags
tst r0, #_TIF_NEED_RESCHED
blne svc_preempt
preempt_return:
ldr r0, [r8, #TI_PREEMPT] @ read preempt value
ldr r0, [tsk, #TI_PREEMPT] @ read preempt value
str r8, [tsk, #TI_PREEMPT] @ restore preempt count
teq r0, r7
str r9, [r8, #TI_PREEMPT] @ restore preempt count
strne r0, [r0, -r0] @ bug()
#endif
ldr r0, [sp, #S_PSR] @ irqs are already disabled
@ -168,7 +168,7 @@ preempt_return:
#ifdef CONFIG_PREEMPT
svc_preempt:
teq r9, #0 @ was preempt count = 0
teq r8, #0 @ was preempt count = 0
ldreq r6, .LCirq_stat
movne pc, lr @ no
ldr r0, [r6, #4] @ local_irq_count
@ -176,9 +176,9 @@ svc_preempt:
adds r0, r0, r1
movne pc, lr
mov r7, #0 @ preempt_schedule_irq
str r7, [r8, #TI_PREEMPT] @ expects preempt_count == 0
str r7, [tsk, #TI_PREEMPT] @ expects preempt_count == 0
1: bl preempt_schedule_irq @ irq en/disable is done inside
ldr r0, [r8, #TI_FLAGS] @ get new tasks TI_FLAGS
ldr r0, [tsk, #TI_FLAGS] @ get new tasks TI_FLAGS
tst r0, #_TIF_NEED_RESCHED
beq preempt_return @ go again
b 1b
@ -338,21 +338,18 @@ __dabt_usr:
__irq_usr:
usr_entry irq
get_thread_info tsk
#ifdef CONFIG_PREEMPT
get_thread_info r8
ldr r9, [r8, #TI_PREEMPT] @ get preempt count
add r7, r9, #1 @ increment it
str r7, [r8, #TI_PREEMPT]
ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
add r7, r8, #1 @ increment it
str r7, [tsk, #TI_PREEMPT]
#endif
irq_handler
#ifdef CONFIG_PREEMPT
ldr r0, [r8, #TI_PREEMPT]
ldr r0, [tsk, #TI_PREEMPT]
str r8, [tsk, #TI_PREEMPT]
teq r0, r7
str r9, [r8, #TI_PREEMPT]
strne r0, [r0, -r0]
mov tsk, r8
#else
get_thread_info tsk
#endif
mov why, #0
b ret_to_user