From 706fdd9faaad5bd52c774190a54c0fd1dfc0f418 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 21 May 2005 18:15:45 +0100 Subject: [PATCH] [PATCH] ARM SMP: reallocate main IRQ handler code registers 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 --- arch/arm/kernel/entry-armv.S | 35 ++++++++++++++++------------------- 1 file changed, 16 insertions(+), 19 deletions(-) diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index b0efbf98..8ff82bc 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -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 -- 2.7.4