powerpc/32s: Slenderize _tlbia() for powerpc 603/603e

_tlbia() is a function used only on 603/603e core, ie on CPUs which
don't have a hash table.

_tlbia() uses the tlbia macro which implements a loop of 1024 tlbie.

On the 603/603e core, flushing the entire TLB requires no more than
32 tlbie.

Replace tlbia by a loop of 32 tlbie.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/12f4f4f0ff89aeab3b937fc96c84fb35e1b2517e.1580748445.git.christophe.leroy@c-s.fr

diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index c11b0a0..a5039ad 100644 (file)
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -696,18 +696,21 @@ _GLOBAL(_tlbia)
        bne-    10b
        stwcx.  r8,0,r9
        bne-    10b
+#endif /* CONFIG_SMP */
+       li      r5, 32
+       lis     r4, KERNELBASE@h
+       mtctr   r5
        sync
-       tlbia
+0:     tlbie   r4
+       addi    r4, r4, 0x1000
+       bdnz    0b
        sync
+#ifdef CONFIG_SMP
        TLBSYNC
        li      r0,0
        stw     r0,0(r9)                /* clear mmu_hash_lock */
        mtmsr   r10
        SYNC_601
        isync
-#else /* CONFIG_SMP */
-       sync
-       tlbia
-       sync
 #endif /* CONFIG_SMP */
        blr