Messages in this thread | | | From | Joakim Tjernlund <> | Subject | Re: [PATCH v2 22/25] powerpc32: move xxxxx_dcache_range() functions inline | Date | Tue, 22 Sep 2015 18:12:27 +0000 |
| |
On Tue, 2015-09-22 at 18:51 +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 */ > +}
This feels optimized for the uncommon case when there is no invalidation. I THINK it would be better to bail early and use do { .. } while(--i); instead.
Jocke
| |