powerpc/pseries: Optimise hcall tracepoints

Now that we execute the hcall tracepoint entry and exit code out of
line, we can use the same stack across both functions.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/platforms/pseries/hvCall.S b/arch/powerpc/platforms/pseries/hvCall.S
index 2f51abf..3fda3f1 100644 (file)
--- a/arch/powerpc/platforms/pseries/hvCall.S
+++ b/arch/powerpc/platforms/pseries/hvCall.S
@@ -46,33 +46,27 @@ hcall_tracepoint_refcount:
        addi    r4,r1,STK_PARAM(FIRST_REG);                     \
        stdu    r1,-STACK_FRAME_OVERHEAD(r1);                   \
        bl      __trace_hcall_entry;                            \
-       addi    r1,r1,STACK_FRAME_OVERHEAD;                     \
-       ld      r0,16(r1);                                      \
-       ld      r3,STK_PARAM(R3)(r1);                           \
-       ld      r4,STK_PARAM(R4)(r1);                           \
-       ld      r5,STK_PARAM(R5)(r1);                           \
-       ld      r6,STK_PARAM(R6)(r1);                           \
-       ld      r7,STK_PARAM(R7)(r1);                           \
-       ld      r8,STK_PARAM(R8)(r1);                           \
-       ld      r9,STK_PARAM(R9)(r1);                           \
-       ld      r10,STK_PARAM(R10)(r1);                         \
-       mtlr    r0
+       ld      r3,STACK_FRAME_OVERHEAD+STK_PARAM(R3)(r1);      \
+       ld      r4,STACK_FRAME_OVERHEAD+STK_PARAM(R4)(r1);      \
+       ld      r5,STACK_FRAME_OVERHEAD+STK_PARAM(R5)(r1);      \
+       ld      r6,STACK_FRAME_OVERHEAD+STK_PARAM(R6)(r1);      \
+       ld      r7,STACK_FRAME_OVERHEAD+STK_PARAM(R7)(r1);      \
+       ld      r8,STACK_FRAME_OVERHEAD+STK_PARAM(R8)(r1);      \
+       ld      r9,STACK_FRAME_OVERHEAD+STK_PARAM(R9)(r1);      \
+       ld      r10,STACK_FRAME_OVERHEAD+STK_PARAM(R10)(r1)
 
 /*
  * postcall is performed immediately before function return which
  * allows liberal use of volatile registers.
  */
 #define __HCALL_INST_POSTCALL                                  \
-       mflr    r0;                                             \
-       ld      r6,STK_PARAM(R3)(r1);                           \
-       std     r3,STK_PARAM(R3)(r1);                           \
+       ld      r0,STACK_FRAME_OVERHEAD+STK_PARAM(R3)(r1);      \
+       std     r3,STACK_FRAME_OVERHEAD+STK_PARAM(R3)(r1);      \
        mr      r4,r3;                                          \
-       mr      r3,r6;                                          \
-       std     r0,16(r1);                                      \
-       stdu    r1,-STACK_FRAME_OVERHEAD(r1);                   \
+       mr      r3,r0;                                          \
        bl      __trace_hcall_exit;                             \
+       ld      r0,STACK_FRAME_OVERHEAD+16(r1);                 \
        addi    r1,r1,STACK_FRAME_OVERHEAD;                     \
-       ld      r0,16(r1);                                      \
        ld      r3,STK_PARAM(R3)(r1);                           \
        mtlr    r0
 
@@ -279,14 +273,14 @@ plpar_hcall9_trace:
        mr      r7,r8
        mr      r8,r9
        mr      r9,r10
-       ld      r10,STK_PARAM(R11)(r1)
-       ld      r11,STK_PARAM(R12)(r1)
-       ld      r12,STK_PARAM(R13)(r1)
+       ld      r10,STACK_FRAME_OVERHEAD+STK_PARAM(R11)(r1)
+       ld      r11,STACK_FRAME_OVERHEAD+STK_PARAM(R12)(r1)
+       ld      r12,STACK_FRAME_OVERHEAD+STK_PARAM(R13)(r1)
 
        HVSC
 
        mr      r0,r12
-       ld      r12,STK_PARAM(R4)(r1)
+       ld      r12,STACK_FRAME_OVERHEAD+STK_PARAM(R4)(r1)
        std     r4,0(r12)
        std     r5,8(r12)
        std     r6,16(r12)