[PATCH v10 02/14] powerpc: move set_soft_enabled() and rename

[Madhavan Srinivasan]

Move set_soft_enabled() from powerpc/kernel/irq.c to
asm/hw_irq.c, to force updates to paca-soft_enabled
done via these access function. Add "memory" clobber
to hint compiler since paca->soft_enabled memory is the target
here

Renaming it as soft_enabled_set() will make
namespaces works better as prefix than a postfix
when new soft_enabled manipulation functions introduced.

Reviewed-by: Nicholas Piggin <npiggin at gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy at linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/hw_irq.h | 12 ++++++++++++
 arch/powerpc/kernel/irq.c         | 12 +++---------
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index d037a57700b9..a6bbda85a2a9 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -47,6 +47,18 @@ extern void unknown_exception(struct pt_regs *regs);
 #ifdef CONFIG_PPC64
 #include <asm/paca.h>
 
+/*
+ * The "memory" clobber acts as both a compiler barrier
+ * for the critical section and as a clobber because
+ * we changed paca->soft_enabled
+ */
+static inline notrace void soft_enabled_set(unsigned long enable)
+{
+	__asm__ __volatile__("stb %0,%1(13)"
+	: : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled))
+	: "memory");
+}
+
 static inline unsigned long arch_local_save_flags(void)
 {
 	unsigned long flags;
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 1c92f0c6ef69..8f561ef3508c 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -107,12 +107,6 @@ static inline notrace unsigned long get_irq_happened(void)
 	return happened;
 }
 
-static inline notrace void set_soft_enabled(unsigned long enable)
-{
-	__asm__ __volatile__("stb %0,%1(13)"
-	: : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
-}
-
 static inline notrace int decrementer_check_overflow(void)
 {
  	u64 now = get_tb_or_rtc();
@@ -225,7 +219,7 @@ notrace void arch_local_irq_restore(unsigned long en)
 	unsigned int replay;
 
 	/* Write the new soft-enabled value */
-	set_soft_enabled(en);
+	soft_enabled_set(en);
 	if (en == IRQ_DISABLED)
 		return;
 	/*
@@ -271,7 +265,7 @@ notrace void arch_local_irq_restore(unsigned long en)
 	}
 #endif /* CONFIG_TRACE_IRQFLAGS */
 
-	set_soft_enabled(IRQ_DISABLED);
+	soft_enabled_set(IRQ_DISABLED);
 
 	/*
 	 * Check if anything needs to be re-emitted. We haven't
@@ -281,7 +275,7 @@ notrace void arch_local_irq_restore(unsigned long en)
 	replay = __check_irq_replay();
 
 	/* We can soft-enable now */
-	set_soft_enabled(IRQ_ENABLED);
+	soft_enabled_set(IRQ_ENABLED);
 
 	/*
 	 * And replay if we have to. This will return with interrupts
-- 
2.7.4