[Zesty][PATCH v3 07/13] powerpc/64s: Avoid a branch for ppc_msgsnd
Gustavo Walbon
gwalbon at linux.vnet.ibm.com
Fri May 26 23:26:24 UTC 2017
From: Nicholas Piggin <npiggin at gmail.com>
IPIs are a pretty hot path and we already have the ability to do asm feature
patching, so use it.
Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
[mpe: Change log detail]
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
(cherry picked from commit a5adf282461fb6048973ca3aec590495bdbc33f1)
Signed-off-by: Gustavo Walbon <gwalbon at linux.vnet.ibm.com>
---
arch/powerpc/include/asm/dbell.h | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/asm/dbell.h b/arch/powerpc/include/asm/dbell.h
index 350694a1a6e5..040944659a20 100644
--- a/arch/powerpc/include/asm/dbell.h
+++ b/arch/powerpc/include/asm/dbell.h
@@ -38,10 +38,8 @@ enum ppc_dbell {
static inline void _ppc_msgsnd(u32 msg)
{
- if (cpu_has_feature(CPU_FTR_HVMODE))
- __asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
- else
- __asm__ __volatile__ (PPC_MSGSNDP(%0) : : "r" (msg));
+ __asm__ __volatile__ (ASM_FTR_IFSET(PPC_MSGSND(%1), PPC_MSGSNDP(%1), %0)
+ : : "i" (CPU_FTR_HVMODE), "r" (msg));
}
/* sync before sending message */
--
2.11.0
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