powerpc/64s/exception: shuffle windup code around

Restore all SPRs and CR up-front, these are longer latency
instructions. Move register restore around to maximise pairs of
adjacent loads (e.g., restore r0 next to r1).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index cbed1e42d85c05ec1c32f2b9fbecaa4450015467..b5060824303b96069c85261905e989f7125945b0 100644 (file)
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -917,13 +917,11 @@ EXC_COMMON_BEGIN(system_reset_common)
        mtxer   r9
        ld      r9,_LINK(r1)
        mtlr    r9
-       REST_GPR(0, r1)
+       ld      r9,_CCR(r1)
+       mtcr    r9
        REST_8GPRS(2, r1)
-       REST_GPR(10, r1)
-       ld      r11,_CCR(r1)
-       mtcr    r11
-       REST_GPR(11, r1)
-       REST_2GPRS(12, r1)
+       REST_4GPRS(10, r1)
+       REST_GPR(0, r1)
        /* restore original r1. */
        ld      r1,GPR1(r1)
        RFI_TO_USER_OR_KERNEL
@@ -1095,13 +1093,11 @@ EXC_COMMON_BEGIN(machine_check_common)
        mtxer   r9;                                     \
        ld      r9,_LINK(r1);                           \
        mtlr    r9;                                     \
-       REST_GPR(0, r1);                                \
+       ld      r9,_CCR(r1);                            \
+       mtcr    r9;                                     \
        REST_8GPRS(2, r1);                              \
-       REST_GPR(10, r1);                               \
-       ld      r11,_CCR(r1);                           \
-       mtcr    r11;                                    \
-       REST_GPR(11, r1);                               \
-       REST_2GPRS(12, r1);                             \
+       REST_4GPRS(10, r1);                             \
+       REST_GPR(0, r1);                                \
        /* restore original r1. */                      \
        ld      r1,GPR1(r1)
 
@@ -1795,13 +1791,11 @@ TRAMP_REAL_BEGIN(hmi_exception_early)
        mtxer   r9
        ld      r9,_LINK(r1)
        mtlr    r9
-       REST_GPR(0, r1)
+       ld      r9,_CCR(r1)
+       mtcr    r9
        REST_8GPRS(2, r1)
-       REST_GPR(10, r1)
-       ld      r11,_CCR(r1)
-       REST_2GPRS(12, r1)
-       mtcr    r11
-       REST_GPR(11, r1)
+       REST_4GPRS(10, r1)
+       REST_GPR(0, r1)
        ld      r1,GPR1(r1)
        HRFI_TO_USER_OR_KERNEL
 
@@ -1816,13 +1810,11 @@ TRAMP_REAL_BEGIN(hmi_exception_early)
        mtxer   r9
        ld      r9,_LINK(r1)
        mtlr    r9
-       REST_GPR(0, r1)
+       ld      r9,_CCR(r1)
+       mtcr    r9
        REST_8GPRS(2, r1)
-       REST_GPR(10, r1)
-       ld      r11,_CCR(r1)
-       REST_2GPRS(12, r1)
-       mtcr    r11
-       REST_GPR(11, r1)
+       REST_4GPRS(10, r1)
+       REST_GPR(0, r1)
        ld      r1,GPR1(r1)
 
        /*