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Commit 0d928b0b authored by Uwe Kleine-König's avatar Uwe Kleine-König
Browse files

Complete irq tracing support for ARM 



Before this patch enabling and disabling irqs in assembler code and by
the hardware wasn't tracked completly.

I had to transpose two instructions in arch/arm/lib/bitops.h because
restore_irqs doesn't preserve the flags with CONFIG_TRACE_IRQFLAGS=y

Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>

Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
parent 181f817e

arch/arm/include/asm/assembler.h

+44 −5
Original line number Diff line number Diff line
@@ -74,23 +74,56 @@ 
 * Enable and disable interrupts

 */

#if __LINUX_ARM_ARCH__ >= 6

	.macro	disable_irq

	.macro	disable_irq_notrace

	cpsid	i

	.endm



	.macro	enable_irq

	.macro	enable_irq_notrace

	cpsie	i

	.endm

#else

	.macro	disable_irq

	.macro	disable_irq_notrace

	msr	cpsr_c, #PSR_I_BIT | SVC_MODE

	.endm



	.macro	enable_irq

	.macro	enable_irq_notrace

	msr	cpsr_c, #SVC_MODE

	.endm

#endif



	.macro asm_trace_hardirqs_off

#if defined(CONFIG_TRACE_IRQFLAGS)

	stmdb   sp!, {r0-r3, ip, lr}

	bl	trace_hardirqs_off

	ldmia	sp!, {r0-r3, ip, lr}

#endif

	.endm



	.macro asm_trace_hardirqs_on_cond, cond

#if defined(CONFIG_TRACE_IRQFLAGS)

	/*

	 * actually the registers should be pushed and pop'd conditionally, but

	 * after bl the flags are certainly clobbered

	 */

	stmdb   sp!, {r0-r3, ip, lr}

	bl\cond	trace_hardirqs_on

	ldmia	sp!, {r0-r3, ip, lr}

#endif

	.endm



	.macro asm_trace_hardirqs_on

	asm_trace_hardirqs_on_cond al

	.endm



	.macro disable_irq

	disable_irq_notrace

	asm_trace_hardirqs_off

	.endm



	.macro enable_irq

	asm_trace_hardirqs_on

	enable_irq_notrace

	.endm

/*

 * Save the current IRQ state and disable IRQs.  Note that this macro

 * assumes FIQs are enabled, and that the processor is in SVC mode.
@@ -104,10 +137,16 @@ 
 * Restore interrupt state previously stored in a register.  We don't

 * guarantee that this will preserve the flags.

 */

	.macro	restore_irqs, oldcpsr

	.macro	restore_irqs_notrace, oldcpsr

	msr	cpsr_c, \oldcpsr

	.endm



	.macro restore_irqs, oldcpsr

	tst	\oldcpsr, #PSR_I_BIT

	asm_trace_hardirqs_on_cond eq

	restore_irqs_notrace \oldcpsr

	.endm



#define USER(x...)				\

9999:	x;					\

	.section __ex_table,"a";		\

arch/arm/kernel/entry-armv.S

+4 −6
Original line number Diff line number Diff line
@@ -151,6 +151,8 @@ ENDPROC(__und_invalid) 
	@  r4 - orig_r0 (see pt_regs definition in ptrace.h)

	@

	stmia	r5, {r0 - r4}



	asm_trace_hardirqs_off

	.endm



	.align	5
@@ -206,9 +208,6 @@ ENDPROC(__dabt_svc) 
__irq_svc:

	svc_entry



#ifdef CONFIG_TRACE_IRQFLAGS

	bl	trace_hardirqs_off

#endif

#ifdef CONFIG_PREEMPT

	get_thread_info tsk

	ldr	r8, [tsk, #TI_PREEMPT]		@ get preempt count
@@ -383,6 +382,8 @@ ENDPROC(__pabt_svc) 
	@ Clear FP to mark the first stack frame

	@

	zero_fp



	asm_trace_hardirqs_off

	.endm



	.macro	kuser_cmpxchg_check
@@ -437,9 +438,6 @@ __irq_usr: 
	usr_entry

	kuser_cmpxchg_check



#ifdef CONFIG_TRACE_IRQFLAGS

	bl	trace_hardirqs_off

#endif

	get_thread_info tsk

#ifdef CONFIG_PREEMPT

	ldr	r8, [tsk, #TI_PREEMPT]		@ get preempt count

arch/arm/lib/bitops.h

+1 −1
Original line number Diff line number Diff line
@@ -60,8 +60,8 @@ 
	tst	r2, r0, lsl r3

	\instr	r2, r2, r0, lsl r3

	\store	r2, [r1]

	restore_irqs ip

	moveq	r0, #0

	restore_irqs ip

	mov	pc, lr

	.endm

#endif