powerpc/32: Remove sync from _switch

64-bit has removed the sync from _switch since commit 9145effd626d1
("powerpc/64: Drop explicit hwsync in context switch"). The same
logic there should apply to 32-bit. Remove the sync and replace with
a placeholder comment (32 and 64 will be merged with a later change).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230606132447.315714-4-npiggin@gmail.com

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 47f0dd9..0894321 100644 (file)
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -243,13 +243,7 @@ _GLOBAL(_switch)
        stw     r10,_CCR(r1)
        stw     r1,KSP(r3)      /* Set old stack pointer */
 
-#ifdef CONFIG_SMP
-       /* We need a sync somewhere here to make sure that if the
-        * previous task gets rescheduled on another CPU, it sees all
-        * stores it has performed on this one.
-        */
-       sync
-#endif /* CONFIG_SMP */
+       /* The sync for SMP migration is taken care of, see entry_64.S */
 
        tophys(r0,r4)
        mtspr   SPRN_SPRG_THREAD,r0     /* Update current THREAD phys addr */