diff mbox series

[v10,03/17] powerpc/64: Improve inline asm in arch_local_irq_disable

Message ID 1513742157-28768-4-git-send-email-maddy@linux.vnet.ibm.com (mailing list archive)
State Accepted
Commit 9f83e00f4cc1c560b6847acecba2b3746c8d8c06
Headers show
Series powerpc: "paca->soft_enabled" based local atomic operation implementation | expand

Commit Message

maddy Dec. 20, 2017, 3:55 a.m. UTC 
From: Nicholas Piggin <npiggin@gmail.com>

arch_local_irq_disable is implemented strangely, with a temporary
output register being set to the desired soft_enabled value via an
immediate input, which is then used to store to memory. This is not
required, the immediate can be specified directly as a register input.

For simple cases at least, assembly is unchanged except register
mapping.

Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/hw_irq.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 463b595ca971..d1e76298e393 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -63,13 +63,13 @@  static inline unsigned long arch_local_save_flags(void)
 
 static inline unsigned long arch_local_irq_disable(void)
 {
-	unsigned long flags, zero;
+	unsigned long flags;
 
 	asm volatile(
-		"li %1,%3; lbz %0,%2(13); stb %1,%2(13)"
-		: "=r" (flags), "=&r" (zero)
-		: "i" (offsetof(struct paca_struct, soft_enabled)),\
-		  "i" (IRQ_DISABLED)
+		"lbz %0,%1(13); stb %2,%1(13)"
+		: "=&r" (flags)
+		: "i" (offsetof(struct paca_struct, soft_enabled)),
+		  "r" (IRQ_DISABLED)
 		: "memory");
 
 	return flags;