* [PATCH 1/2] ARM: Consolidate preempt enable/disable assembly into macros
2013-03-04 22:43 [PATCH 0/2] Call tracing/debug code in VFP preempt code Stephen Boyd
@ 2013-03-04 22:43 ` Stephen Boyd
2013-03-04 22:43 ` [PATCH 2/2] ARM: Enable tracing around vfp preemption enable/disable Stephen Boyd
1 sibling, 0 replies; 3+ messages in thread
From: Stephen Boyd @ 2013-03-04 22:43 UTC (permalink / raw)
To: linux-arm-kernel
We duplicate the same few preempt enable and disable assembly
instructions in multiple places in the vfp code. Move the code to
a macro in entry-header.S so that we can modify the preempt
enable/disable assembly in one place in the future.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
| 17 +++++++++++++++++
arch/arm/vfp/entry.S | 20 +++-----------------
arch/arm/vfp/vfphw.S | 14 ++------------
3 files changed, 22 insertions(+), 29 deletions(-)
--git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 9a8531e..130e6a6 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -163,6 +163,23 @@
.endm
#endif /* !CONFIG_THUMB2_KERNEL */
+ .macro preempt_enable_no_resched, tsk, cnt
+#ifdef CONFIG_PREEMPT_COUNT
+ get_thread_info \tsk
+ ldr \cnt, [\tsk, #TI_PREEMPT] @ get preempt count
+ sub \cnt, \cnt, #1 @ decrement it
+ str \cnt, [\tsk, #TI_PREEMPT]
+#endif
+ .endm
+
+ .macro preempt_disable, tsk, cnt
+#ifdef CONFIG_PREEMPT_COUNT
+ ldr \cnt, [\tsk, #TI_PREEMPT] @ get preempt count
+ add \cnt, \cnt, #1 @ increment it
+ str \cnt, [\tsk, #TI_PREEMPT]
+#endif
+ .endm
+
/*
* These are the registers used in the syscall handler, and allow us to
* have in theory up to 7 arguments to a function - r0 to r6.
diff --git a/arch/arm/vfp/entry.S b/arch/arm/vfp/entry.S
index 323ce1a..e528709 100644
--- a/arch/arm/vfp/entry.S
+++ b/arch/arm/vfp/entry.S
@@ -22,11 +22,7 @@
@ IRQs disabled.
@
ENTRY(do_vfp)
-#ifdef CONFIG_PREEMPT_COUNT
- ldr r4, [r10, #TI_PREEMPT] @ get preempt count
- add r11, r4, #1 @ increment it
- str r11, [r10, #TI_PREEMPT]
-#endif
+ preempt_disable r10, r4
enable_irq
ldr r4, .LCvfp
ldr r11, [r10, #TI_CPU] @ CPU number
@@ -35,12 +31,7 @@ ENTRY(do_vfp)
ENDPROC(do_vfp)
ENTRY(vfp_null_entry)
-#ifdef CONFIG_PREEMPT_COUNT
- get_thread_info r10
- ldr r4, [r10, #TI_PREEMPT] @ get preempt count
- sub r11, r4, #1 @ decrement it
- str r11, [r10, #TI_PREEMPT]
-#endif
+ preempt_enable_no_resched r10, r4
mov pc, lr
ENDPROC(vfp_null_entry)
@@ -53,12 +44,7 @@ ENDPROC(vfp_null_entry)
__INIT
ENTRY(vfp_testing_entry)
-#ifdef CONFIG_PREEMPT_COUNT
- get_thread_info r10
- ldr r4, [r10, #TI_PREEMPT] @ get preempt count
- sub r11, r4, #1 @ decrement it
- str r11, [r10, #TI_PREEMPT]
-#endif
+ preempt_enable_no_resched r10, r4
ldr r0, VFP_arch_address
str r5, [r0] @ known non-zero value
mov pc, r9 @ we have handled the fault
diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S
index dd5e56f..8bae250 100644
--- a/arch/arm/vfp/vfphw.S
+++ b/arch/arm/vfp/vfphw.S
@@ -168,12 +168,7 @@ vfp_hw_state_valid:
@ else it's one 32-bit instruction, so
@ always subtract 4 from the following
@ instruction address.
-#ifdef CONFIG_PREEMPT_COUNT
- get_thread_info r10
- ldr r4, [r10, #TI_PREEMPT] @ get preempt count
- sub r11, r4, #1 @ decrement it
- str r11, [r10, #TI_PREEMPT]
-#endif
+ preempt_enable_no_resched r10, r4
mov pc, r9 @ we think we have handled things
@@ -192,12 +187,7 @@ look_for_VFP_exceptions:
@ not recognised by VFP
DBGSTR "not VFP"
-#ifdef CONFIG_PREEMPT_COUNT
- get_thread_info r10
- ldr r4, [r10, #TI_PREEMPT] @ get preempt count
- sub r11, r4, #1 @ decrement it
- str r11, [r10, #TI_PREEMPT]
-#endif
+ preempt_enable_no_resched r10, r4
mov pc, lr
process_exception:
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation
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* [PATCH 2/2] ARM: Enable tracing around vfp preemption enable/disable
2013-03-04 22:43 [PATCH 0/2] Call tracing/debug code in VFP preempt code Stephen Boyd
2013-03-04 22:43 ` [PATCH 1/2] ARM: Consolidate preempt enable/disable assembly into macros Stephen Boyd
@ 2013-03-04 22:43 ` Stephen Boyd
1 sibling, 0 replies; 3+ messages in thread
From: Stephen Boyd @ 2013-03-04 22:43 UTC (permalink / raw)
To: linux-arm-kernel
The VFP code enables and disables preemption but doesn't call
into the tracer except for in the VFP bounce code to say that
preemption has been enabled again. Trace the preemption disable
and enable calls made in assembly so that we can accurately
measure how long preemption is disabled while handling VFP
exceptions.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
| 14 ++++++++++++++
1 file changed, 14 insertions(+)
--git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 130e6a6..75bcb18 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -165,19 +165,33 @@
.macro preempt_enable_no_resched, tsk, cnt
#ifdef CONFIG_PREEMPT_COUNT
+#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
+ stmdb sp!, {r0-r3, ip, lr}
+ mov r0, #1
+ bl sub_preempt_count
+ ldmia sp!, {r0-r3, ip, lr}
+#else
get_thread_info \tsk
ldr \cnt, [\tsk, #TI_PREEMPT] @ get preempt count
sub \cnt, \cnt, #1 @ decrement it
str \cnt, [\tsk, #TI_PREEMPT]
#endif
+#endif
.endm
.macro preempt_disable, tsk, cnt
#ifdef CONFIG_PREEMPT_COUNT
+#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
+ stmdb sp!, {r0-r3, ip, lr}
+ mov r0, #1
+ bl add_preempt_count
+ ldmia sp!, {r0-r3, ip, lr}
+#else
ldr \cnt, [\tsk, #TI_PREEMPT] @ get preempt count
add \cnt, \cnt, #1 @ increment it
str \cnt, [\tsk, #TI_PREEMPT]
#endif
+#endif
.endm
/*
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation
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