Re: [PATCH] ARM: Re-enable TRACE_IRQFLAGS_SUPPORT on ARMv7-M

From: Daniel Thompson
Date: Tue Jun 09 2015 - 07:42:04 EST


On 09/06/15 10:14, Maxime Coquelin wrote:
The real solution is to provide a definition _in asm-generic_ for
arch_irqs_disabled(), rather than having almost every arch doing:

static inline bool arch_irqs_disabled(void)
{
return arch_irqs_disabled_flags(arch_local_save_flags());
}

I'm personally refusing to take a patch for ARM which adds yet another
copy of the above. This is, after all, exactly the kind of stuff that
should be in asm-generic, or if not, in include/linux but overridable
by arch stuff.

We keep going between the two extremes of "lets push lots of stuff into
arch stuff" and "lets try to extract the common bits out of arch code".

Let's try and settle on one approach, and apply it universally.

I agree on the idea but I don't measure all the impacts it would have.

Hey Maxime, just out of interest...

Does the following patch, which makes the arch_irqs_disabled() implementation from asm-generic available on arm, fix the build for you?

I've only done a real quick 'n dirty check for regression: multi_v7_defconfig still works ;-)

If the patch is useful I can test it a bit harder...


From d86ef4466cfdbe622a65bcc7e72a8ca0d1dd2879 Mon Sep 17 00:00:00 2001
From: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
Date: Tue, 9 Jun 2015 12:35:24 +0100
Subject: [PATCH] ARM: irqflags: Get arch_irqs_disabled from asm-generic

asm-generic/irqflags.h provides an implementation of
arch_irqs_disabled(). Lets grab that implementation.

Suggested-by: Russell King <linux@xxxxxxxxxxxxxxxx>
Signed-off-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
---
arch/arm/include/asm/irqflags.h | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/arch/arm/include/asm/irqflags.h b/arch/arm/include/asm/irqflags.h
index 3b763d6652a0..43908146a5cf 100644
--- a/arch/arm/include/asm/irqflags.h
+++ b/arch/arm/include/asm/irqflags.h
@@ -20,6 +20,7 @@

#if __LINUX_ARM_ARCH__ >= 6

+#define arch_local_irq_save arch_local_irq_save
static inline unsigned long arch_local_irq_save(void)
{
unsigned long flags;
@@ -31,6 +32,7 @@ static inline unsigned long arch_local_irq_save(void)
return flags;
}

+#define arch_local_irq_enable arch_local_irq_enable
static inline void arch_local_irq_enable(void)
{
asm volatile(
@@ -40,6 +42,7 @@ static inline void arch_local_irq_enable(void)
: "memory", "cc");
}

+#define arch_local_irq_disable arch_local_irq_disable
static inline void arch_local_irq_disable(void)
{
asm volatile(
@@ -56,6 +59,7 @@ static inline void arch_local_irq_disable(void)
/*
* Save the current interrupt enable state & disable IRQs
*/
+#define arch_local_irq_save arch_local_irq_save
static inline unsigned long arch_local_irq_save(void)
{
unsigned long flags, temp;
@@ -73,6 +77,7 @@ static inline unsigned long arch_local_irq_save(void)
/*
* Enable IRQs
*/
+#define arch_local_irq_enable arch_local_irq_enable
static inline void arch_local_irq_enable(void)
{
unsigned long temp;
@@ -88,6 +93,7 @@ static inline void arch_local_irq_enable(void)
/*
* Disable IRQs
*/
+#define arch_local_irq_disable arch_local_irq_disable
static inline void arch_local_irq_disable(void)
{
unsigned long temp;
@@ -135,6 +141,7 @@ static inline void arch_local_irq_disable(void)
/*
* Save the current interrupt enable state.
*/
+#define arch_local_save_flags arch_local_save_flags
static inline unsigned long arch_local_save_flags(void)
{
unsigned long flags;
@@ -147,6 +154,7 @@ static inline unsigned long arch_local_save_flags(void)
/*
* restore saved IRQ & FIQ state
*/
+#define arch_local_irq_restore arch_local_irq_restore
static inline void arch_local_irq_restore(unsigned long flags)
{
asm volatile(
@@ -156,10 +164,13 @@ static inline void arch_local_irq_restore(unsigned long flags)
: "memory", "cc");
}

+#define arch_irqs_disabled_flags arch_irqs_disabled_flags
static inline int arch_irqs_disabled_flags(unsigned long flags)
{
return flags & IRQMASK_I_BIT;
}

+#include <asm-generic/irqflags.h>
+
#endif /* ifdef __KERNEL__ */
#endif /* ifndef __ASM_ARM_IRQFLAGS_H */
--
2.4.2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/