[PATCH v2] arm64: dbm: Invalidate local TLB when setting TCR_EL1.HD

[Will Deacon]

TCR_EL1.HD is permitted to be cached in a TLB, so invalidate the local
TLB after setting the bit when detected support for the feature. Although
this isn't strictly necessary, since we can happily operate with the bit
effectively clear, the current code uses an ISB in a half-hearted attempt
to make the change effective, so let's just fix that up.

Cc: Catalin Marinas <catalin.marinas at arm.com>
Signed-off-by: Will Deacon <will at kernel.org>
---

v1 -> v2: Retain isb() prior to TLB invalidation.

 arch/arm64/kernel/cpufeature.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 6424584be01e..a474a4f39c95 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1443,6 +1443,7 @@ static inline void __cpu_enable_hw_dbm(void)
 
 	write_sysreg(tcr, tcr_el1);
 	isb();
+	local_flush_tlb_all();
 }
 
 static bool cpu_has_broken_dbm(void)
-- 
2.28.0.709.gb0816b6eb0-goog