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

Christophe Leroy christophe.leroy at c-s.fr
Tue Feb 4 03:47:37 AEDT 2020


_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 at c-s.fr>
---
 arch/powerpc/mm/book3s32/hash_low.S | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index c11b0a005196..a5039ad10429 100644
--- 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 at 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
-- 
2.25.0



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