[PATCH v2 1/3] ARM: cache-v7: add missing ISB after cache level selection
Ard Biesheuvel
ardb at kernel.org
Wed Feb 10 13:55:30 EST 2021
A write to CCSELR needs to complete before its results can be observed
via CCSIDR. So add a ISB to ensure that this is the case.
Acked-by: Nicolas Pitre <nico at fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb at kernel.org>
---
arch/arm/mm/cache-v7.S | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
index dc8f152f3556..307f381eee71 100644
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -38,9 +38,10 @@ icache_size:
* procedures.
*/
ENTRY(v7_invalidate_l1)
- mov r0, #0
- mcr p15, 2, r0, c0, c0, 0
- mrc p15, 1, r0, c0, c0, 0
+ mov r0, #0
+ mcr p15, 2, r0, c0, c0, 0 @ select L1 data cache in CSSELR
+ isb
+ mrc p15, 1, r0, c0, c0, 0 @ read cache geometry from CCSIDR
movw r1, #0x7fff
and r2, r1, r0, lsr #13
--
2.30.0
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