[PATCH 07/23] ARM: entry: no need to increase preempt count for IRQ handlers
From: Russell King - ARM Linux <hidden>
Date: 2011-06-29 09:21:14
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
irq_enter() and irq_exit() already take care of the preempt_count handling for interrupts, which increment and decrement the hardirq bits of the preempt count. So we can remove the preempt count handing in our IRQ entry/exit assembly, like x86 did some 9 years ago. Signed-off-by: Russell King <redacted> --- arch/arm/kernel/entry-armv.S | 27 ++++----------------------- 1 files changed, 4 insertions(+), 23 deletions(-)
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 6855f6d..1e5f387 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S@@ -220,16 +220,12 @@ __irq_svc: #ifdef CONFIG_TRACE_IRQFLAGS bl trace_hardirqs_off #endif -#ifdef CONFIG_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 - str r8, [tsk, #TI_PREEMPT] @ restore preempt count + get_thread_info tsk + ldr r8, [tsk, #TI_PREEMPT] @ get preempt count ldr r0, [tsk, #TI_FLAGS] @ get flags teq r8, #0 @ if preempt count != 0 movne r0, #0 @ force flags to 0
@@ -432,23 +428,8 @@ __irq_usr: bl trace_hardirqs_off #endif - get_thread_info tsk -#ifdef CONFIG_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, [tsk, #TI_PREEMPT] - str r8, [tsk, #TI_PREEMPT] - teq r0, r7 - ARM( strne r0, [r0, -r0] ) - THUMB( movne r0, #0 ) - THUMB( strne r0, [r0] ) -#endif - + get_thread_info tsk mov why, #0 b ret_to_user_from_irq UNWIND(.fnend )
--
1.7.4.4