Le 29/09/2015 02:29, Scott Wood a écrit :
On Tue, Sep 22, 2015 at 06:51:13PM +0200, Christophe Leroy wrote:
flush/clean/invalidate _dcache_range() functions are all very
similar and are quite short. They are mainly used in __dma_sync()
perf_event locate them in the top 3 consumming functions during
heavy ethernet activity
They are good candidate for inlining, as __dma_sync() does
almost nothing but calling them
Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
---
New in v2
arch/powerpc/include/asm/cacheflush.h | 55 +++++++++++++++++++++++++++--
arch/powerpc/kernel/misc_32.S | 65 -----------------------------------
arch/powerpc/kernel/ppc_ksyms.c | 2 ++
3 files changed, 54 insertions(+), 68 deletions(-)
diff --git a/arch/powerpc/include/asm/cacheflush.h
b/arch/powerpc/include/asm/cacheflush.h
index 6229e6b..6169604 100644
--- a/arch/powerpc/include/asm/cacheflush.h
+++ b/arch/powerpc/include/asm/cacheflush.h
@@ -47,12 +47,61 @@ static inline void __flush_dcache_icache_phys(unsigned long
physaddr)
}
#endif
-extern void flush_dcache_range(unsigned long start, unsigned long stop);
#ifdef CONFIG_PPC32
-extern void clean_dcache_range(unsigned long start, unsigned long stop);
-extern void invalidate_dcache_range(unsigned long start, unsigned long stop);
+/*
+ * Write any modified data cache blocks out to memory and invalidate them.
+ * Does not invalidate the corresponding instruction cache blocks.
+ */
+static inline void flush_dcache_range(unsigned long start, unsigned long stop)
+{
+ void *addr = (void *)(start & ~(L1_CACHE_BYTES - 1));
+ unsigned int size = stop - (unsigned long)addr + (L1_CACHE_BYTES - 1);
+ unsigned int i;
+
+ for (i = 0; i < size >> L1_CACHE_SHIFT; i++, addr += L1_CACHE_BYTES)
+ dcbf(addr);
+ if (i)
+ mb(); /* sync */
+}
I know this is 32-bit-specific code, but it's still bad practice to use
"unsigned int" for addresses or sizes thereof.
Ok, I can fix size, but what about start and stop ? If I change that, it
means I also have to fix all caller. Do you expect me to do that ?
And it is very unlykely, but what if for some reason someone wants to
invalidate the entire user address space which is 3Gbytes size ? A
signed size would be negative here.
Christophe
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