powerpc/32: Rearrange _switch to prepare for 32/64 merge

Change the order of some operations and change some register numbers in
preparation to merge 32-bit and 64-bit switch.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230606132447.315714-5-npiggin@gmail.com

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0894321285715b0c011ee3f1111fb5400f53036c..2d17b14bb9e5e2d2d8df870498dc7cda296b6f15 100644 (file)
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -236,12 +236,12 @@ _GLOBAL(_switch)
        stwu    r1,-SWITCH_FRAME_SIZE(r1)
        mflr    r0
        stw     r0,SWITCH_FRAME_SIZE+4(r1)
+       stw     r1,KSP(r3)      /* Set old stack pointer */
        /* r3-r12 are caller saved -- Cort */
        SAVE_NVGPRS(r1)
        stw     r0,_NIP(r1)     /* Return to switch caller */
-       mfcr    r10
-       stw     r10,_CCR(r1)
-       stw     r1,KSP(r3)      /* Set old stack pointer */
+       mfcr    r0
+       stw     r0,_CCR(r1)
 
        /* The sync for SMP migration is taken care of, see entry_64.S */
 
@@ -258,8 +258,8 @@ _GLOBAL(_switch)
        /* r3-r12 are destroyed -- Cort */
        REST_NVGPRS(r1)
 
-       lwz     r4,_NIP(r1)     /* Return to _switch caller in new task */
-       mtlr    r4
+       lwz     r0,_NIP(r1)     /* Return to _switch caller in new task */
+       mtlr    r0
        addi    r1,r1,SWITCH_FRAME_SIZE
        blr