2020-02-03 19:07:08

by Christophe Leroy

Subject: [PATCH] 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 <[email protected]>
---
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@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

2020-03-06 00:28:29

by Michael Ellerman

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

On Mon, 2020-02-03 at 16:47:37 UTC, Christophe Leroy wrote:
> _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 <[email protected]>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/e1347a020b81fe47c80cd277bfaa61295a9482a4

cheers