path: root/arch
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authorMarc Zyngier <maz@kernel.org>2021-02-24 09:37:37 +0000
committerWill Deacon <will@kernel.org>2021-02-24 11:35:19 +0000
commit9d41053e8dc115c92b8002c3db5f545d7602498b (patch)
treea14327d4f3d8d4e43f72c0a9a56e80893aaacc5e /arch
parentf1b6cff7c98be2747d2fe16e42dcdcf2fc02c7e6 (diff)
arm64: Add missing ISB after invalidating TLB in __primary_switch
Although there has been a bit of back and forth on the subject, it appears that invalidating TLBs requires an ISB instruction when FEAT_ETS is not implemented by the CPU. From the bible: | In an implementation that does not implement FEAT_ETS, a TLB | maintenance instruction executed by a PE, PEx, can complete at any | time after it is issued, but is only guaranteed to be finished for a | PE, PEx, after the execution of DSB by the PEx followed by a Context | synchronization event Add the missing ISB in __primary_switch, just in case. Fixes: 3c5e9f238bc4 ("arm64: head.S: move KASLR processing out of __enable_mmu()") Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20210224093738.3629662-3-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch')
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 1e30b5550d2a..66b0e0b66e31 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -837,6 +837,7 @@ SYM_FUNC_START_LOCAL(__primary_switch)
tlbi vmalle1 // Remove any stale TLB entries
dsb nsh
+ isb
set_sctlr_el1 x19 // re-enable the MMU