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authorMichael Neuling <mikey@neuling.org>2013-05-29 19:34:29 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-06-01 08:29:26 +1000
commit280a5ba22ca35575721d42e536176a3561f4ec43 (patch)
tree1f3d8d44e8fe3fdcd30bd45a0b881a0d878cd7b2
parenta515348fc69fd1d9e8ebd34a16f1026d7fe32048 (diff)
downloadlinux-280a5ba22ca35575721d42e536176a3561f4ec43.tar.gz
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 <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r--arch/powerpc/lib/copypage_power7.S19
-rw-r--r--arch/powerpc/lib/copyuser_power7.S12
2 files changed, 18 insertions, 13 deletions
diff --git a/arch/powerpc/lib/copypage_power7.S b/arch/powerpc/lib/copypage_power7.S
index 0ef75bf0695..395c594722a 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
diff --git a/arch/powerpc/lib/copyuser_power7.S b/arch/powerpc/lib/copyuser_power7.S
index 0d24ff15f5f..d1f11795a7a 100644
--- a/arch/powerpc/lib/copyuser_power7.S
+++ b/arch/powerpc/lib/copyuser_power7.S
@@ -318,12 +318,14 @@ err1; stb r0,0(r3)
.machine push
.machine "power4"
- dcbt r0,r6,0b01000
- dcbt r0,r7,0b01010
- dcbtst r0,r9,0b01000
- dcbtst r0,r10,0b01010
+ /* setup read stream 0 */
+ dcbt r0,r6,0b01000 /* 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
beq cr1,.Lunwind_stack_nonvmx_copy