[PATCH 4.14 121/166] arm64/cpufeature: Drop TraceFilt feature exposure from ID_DFR0 register

Greg Kroah-Hartman gregkh at linuxfoundation.org
Tue Sep 29 07:00:33 EDT 2020


From: Anshuman Khandual <anshuman.khandual at arm.com>

[ Upstream commit 1ed1b90a0594c8c9d31e8bb8be25a2b37717dc9e ]

ID_DFR0 based TraceFilt feature should not be exposed to guests. Hence lets
drop it.

Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Will Deacon <will at kernel.org>
Cc: Marc Zyngier <maz at kernel.org>
Cc: Mark Rutland <mark.rutland at arm.com>
Cc: James Morse <james.morse at arm.com>
Cc: Suzuki K Poulose <suzuki.poulose at arm.com>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-kernel at vger.kernel.org

Suggested-by: Mark Rutland <mark.rutland at arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual at arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose at arm.com>
Link: https://lore.kernel.org/r/1589881254-10082-3-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will at kernel.org>
Signed-off-by: Sasha Levin <sashal at 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 b7d400a8921db..174aa12fb8b1f 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -272,7 +272,7 @@ static const struct arm64_ftr_bits ftr_id_pfr0[] = {
 };
 
 static const struct arm64_ftr_bits ftr_id_dfr0[] = {
-	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
+	/* [31:28] TraceFilt */
 	S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0xf),	/* PerfMon */
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
-- 
2.25.1






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