[PATCH 1/3] powerpc: move the testing of CPU_FTR_COHERENT_ICACHE into __flush_icache_range

Kevin Hao haokexin at gmail.com
Tue Aug 6 20:23:30 EST 2013


In function flush_icache_range(), we use cpu_has_feature() to test
the feature bit of CPU_FTR_COHERENT_ICACHE. But this seems not optimal
for two reasons:
 a) For ppc32, the function __flush_icache_range() already do this
    check with the macro END_FTR_SECTION_IFSET.
 b) Compare with the cpu_has_feature(), the method of using macro
    END_FTR_SECTION_IFSET will not introduce any runtime overhead.

Signed-off-by: Kevin Hao <haokexin at gmail.com>
---
 arch/powerpc/include/asm/cacheflush.h | 3 +--
 arch/powerpc/kernel/misc_64.S         | 4 +++-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/cacheflush.h b/arch/powerpc/include/asm/cacheflush.h
index b843e35..60b620d 100644
--- a/arch/powerpc/include/asm/cacheflush.h
+++ b/arch/powerpc/include/asm/cacheflush.h
@@ -35,8 +35,7 @@ extern void __flush_disable_L1(void);
 extern void __flush_icache_range(unsigned long, unsigned long);
 static inline void flush_icache_range(unsigned long start, unsigned long stop)
 {
-	if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
-		__flush_icache_range(start, stop);
+	__flush_icache_range(start, stop);
 }
 
 extern void flush_icache_user_range(struct vm_area_struct *vma,
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 6820e45..74d87f1 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -68,7 +68,9 @@ PPC64_CACHES:
  */
 
 _KPROBE(__flush_icache_range)
-
+BEGIN_FTR_SECTION
+	blr
+END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
 /*
  * Flush the data cache to memory 
  * 
-- 
1.8.3.1



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