Re: [PATCH v2 22/25] powerpc32: move xxxxx_dcache_range() functions inline
flat view
From: Joakim Tjernlund <hidden>
Date: 2015-09-22 18:12:32
Also in:
lkml
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 =20 They are good candidate for inlining, as __dma_sync() does almost nothing but calling them =20 Signed-off-by: Christophe Leroy <redacted> --- New in v2 =20 arch/powerpc/include/asm/cacheflush.h | 55 +++++++++++++++++++++++++++-- arch/powerpc/kernel/misc_32.S | 65 -----------------------------=
------
quoted hunk ↗ jump to hunk
arch/powerpc/kernel/ppc_ksyms.c | 2 ++ 3 files changed, 54 insertions(+), 68 deletions(-) =20diff --git a/arch/powerpc/include/asm/cacheflush.h b/arch/powerpc/include=
/asm/cacheflush.h
quoted hunk ↗ jump to hunk
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(unsigne=
d long physaddr)
} #endif =20 -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 s=
top);
+/* + * Write any modified data cache blocks out to memory and invalidate the=
m.
quoted hunk ↗ jump to hunk
+ * Does not invalidate the corresponding instruction cache blocks. + */ +static inline void flush_dcache_range(unsigned long start, unsigned long=
stop)
quoted hunk ↗ jump to hunk
+{ + void *addr =3D (void *)(start & ~(L1_CACHE_BYTES - 1)); + unsigned int size =3D stop - (unsigned long)addr + (L1_CACHE_BYTES - 1)=
;
quoted hunk ↗ jump to hunk
+ unsigned int i; + + for (i =3D 0; i < size >> L1_CACHE_SHIFT; i++, addr +=3D L1_CACHE_BYTES=
)
quoted hunk ↗ jump to hunk
+ 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); inst=
ead.
Jocke=