Thread (4 messages) flat view 4 messages, 3 authors, 2020-03-06

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

From: Joakim Tjernlund <hidden>
Date: 2020-02-03 16:57:26
Also in: lkml

On Mon, 2020-02-03 at 16:47 +0000, Christophe Leroy wrote:
quoted hunk ↗ jump to hunk
CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.


_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 <redacted>
---
 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
Is page size always 4096 here or does it not matter ?
+       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
  
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help