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>
diff --git a/arch/powerpc/lib/copyuser_power7.S b/arch/powerpc/lib/copyuser_power7.S
index 0d24ff1..d1f1179 100644
--- a/arch/powerpc/lib/copyuser_power7.S
+++ b/arch/powerpc/lib/copyuser_power7.S
@@ -318,12 +318,14 @@
.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