Messages in this thread | | | Subject | Re: [PATCH v2 22/25] powerpc32: move xxxxx_dcache_range() functions inline | From | Christophe Leroy <> | Date | Wed, 7 Oct 2015 14:49:24 +0200 |
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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.leroy@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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