From 280a5ba22ca35575721d42e536176a3561f4ec43 Mon Sep 17 00:00:00 2001 From: Michael Neuling Date: Wed, 29 May 2013 19:34:29 +0000 Subject: powerpc/pseries: Improve stream generation comments in copypage/user No code changes, just documenting what's happening a little better. Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/lib/copypage_power7.S | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) (limited to 'arch/powerpc/lib/copypage_power7.S') diff --git a/arch/powerpc/lib/copypage_power7.S b/arch/powerpc/lib/copypage_power7.S index 0ef75bf0695c..395c594722a2 100644 --- a/arch/powerpc/lib/copypage_power7.S +++ b/arch/powerpc/lib/copypage_power7.S @@ -28,13 +28,14 @@ _GLOBAL(copypage_power7) * aligned we don't need to clear the bottom 7 bits of either * address. */ - ori r9,r3,1 /* stream=1 */ + ori r9,r3,1 /* stream=1 => to */ #ifdef CONFIG_PPC_64K_PAGES - lis r7,0x0E01 /* depth=7, units=512 */ + lis r7,0x0E01 /* depth=7 + * units/cachelines=512 */ #else lis r7,0x0E00 /* depth=7 */ - ori r7,r7,0x1000 /* units=32 */ + ori r7,r7,0x1000 /* units/cachelines=32 */ #endif ori r10,r7,1 /* stream=1 */ @@ -43,12 +44,14 @@ _GLOBAL(copypage_power7) .machine push .machine "power4" - dcbt r0,r4,0b01000 - dcbt r0,r7,0b01010 - dcbtst r0,r9,0b01000 - dcbtst r0,r10,0b01010 + /* setup read stream 0 */ + dcbt r0,r4,0b01000 /* addr from */ + dcbt r0,r7,0b01010 /* length and depth from */ + /* setup write stream 1 */ + dcbtst r0,r9,0b01000 /* addr to */ + dcbtst r0,r10,0b01010 /* length and depth to */ eieio - dcbt r0,r8,0b01010 /* GO */ + dcbt r0,r8,0b01010 /* all streams GO */ .machine pop #ifdef CONFIG_ALTIVEC -- cgit v1.2.3