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From: Will Deacon <will@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>
Subject: [PATCH] arm64: dbm: Invalidate local TLB when setting TCR_EL1.HD
Date: Thu,  1 Oct 2020 10:39:20 +0100	[thread overview]
Message-ID: <20201001093920.18260-1-will@kernel.org> (raw)

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@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
 arch/arm64/kernel/cpufeature.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 6424584be01e..29de76046977 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1442,7 +1442,7 @@ static inline void __cpu_enable_hw_dbm(void)
 	u64 tcr = read_sysreg(tcr_el1) | TCR_HD;
 
 	write_sysreg(tcr, tcr_el1);
-	isb();
+	local_flush_tlb_all();
 }
 
 static bool cpu_has_broken_dbm(void)
-- 
2.28.0.709.gb0816b6eb0-goog


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             reply	other threads:[~2020-10-01  9:41 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-01  9:39 Will Deacon [this message]
2020-10-01  9:52 ` [PATCH] arm64: dbm: Invalidate local TLB when setting TCR_EL1.HD Catalin Marinas
2020-10-01 10:32   ` Will Deacon
2020-10-01 10:33   ` Mark Rutland

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