linux-kernel - [PATCH v2 4/8] arm64: cpufeature: Remove redundant call to id_aa64pfr0_32bit

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Date:   Tue, 21 Apr 2020 15:29:18 +0100
From:   Will Deacon <will@...nel.org>
To:     linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.cs.columbia.edu
Cc:     linux-kernel@...r.kernel.org, Will Deacon <will@...nel.org>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Mark Rutland <mark.rutland@....com>,
        Marc Zyngier <maz@...nel.org>,
        Anshuman Khandual <anshuman.khandual@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Sai Prakash Ranjan <saiprakash.ranjan@...eaurora.org>,
        Doug Anderson <dianders@...omium.org>, kernel-team@...roid.com
Subject: [PATCH v2 4/8] arm64: cpufeature: Remove redundant call to id_aa64pfr0_32bit_el0()

There's no need to call id_aa64pfr0_32bit_el0() twice because the
sanitised value of ID_AA64PFR0_EL1 has already been updated for the CPU
being onlined.

Remove the redundant function call.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@....com>
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@...eaurora.org>
Signed-off-by: Will Deacon <will@...nel.org>
---
 arch/arm64/kernel/cpufeature.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 838fe5cc8d7e..7dfcdd9e75c1 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -792,9 +792,7 @@ void update_cpu_features(int cpu,
 	 * If we have AArch32, we care about 32-bit features for compat.
 	 * If the system doesn't support AArch32, don't update them.
 	 */
-	if (id_aa64pfr0_32bit_el0(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
-		id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
-
+	if (id_aa64pfr0_32bit_el0(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1))) {
 		taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
 					info->reg_id_dfr0, boot->reg_id_dfr0);
 		taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
-- 
2.26.1.301.g55bc3eb7cb9-goog