linux-kernel - [PATCH 2/4] x86/cpuid: refactor setup_clear_cpu_cap/clear

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Message-Id: <20220622144820.751402-3-mlevitsk@redhat.com>
Date:   Wed, 22 Jun 2022 17:48:18 +0300
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     linux-kernel@...r.kernel.org
Cc:     "Chang S. Bae" <chang.seok.bae@...el.com>,
        Jiri Olsa <jolsa@...nel.org>, linux-perf-users@...r.kernel.org,
        Peter Zijlstra <peterz@...radead.org>,
        "H. Peter Anvin" <hpa@...or.com>,
        "David S. Miller" <davem@...emloft.net>,
        Borislav Petkov <bp@...en8.de>,
        Kees Cook <keescook@...omium.org>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Namhyung Kim <namhyung@...nel.org>,
        Tim Chen <tim.c.chen@...ux.intel.com>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        x86@...nel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
        Jane Malalane <jane.malalane@...rix.com>,
        Tony Luck <tony.luck@...el.com>,
        Ingo Molnar <mingo@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        linux-crypto@...r.kernel.org (open list:CRYPTO API),
        Paolo Bonzini <pbonzini@...hat.com>
Subject: [PATCH 2/4] x86/cpuid: refactor setup_clear_cpu_cap/clear_feature

Simplify the code a bit by always passing &boot_cpu_data
in case the setup_clear_cpu_cap was called.

Also unify clear_cpu_cap and do_clear_cpu_cap.

Signed-off-by: Maxim Levitsky <mlevitsk@...hat.com>
---
 arch/x86/kernel/cpu/cpuid-deps.c | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index c881bcafba7d70..d6777d07ba3302 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -88,18 +88,16 @@ static inline void clear_feature(struct cpuinfo_x86 *c, unsigned int feature)
 	 * rest of the cpufeature code uses atomics as well, so keep it for
 	 * consistency. Cleanup all of it separately.
 	 */
-	if (!c) {
-		clear_cpu_cap(&boot_cpu_data, feature);
+	clear_bit(feature, (unsigned long *)c->x86_capability);
+
+	if (c == &boot_cpu_data)
 		set_bit(feature, (unsigned long *)cpu_caps_cleared);
-	} else {
-		clear_bit(feature, (unsigned long *)c->x86_capability);
-	}
 }
 
 /* Take the capabilities and the BUG bits into account */
 #define MAX_FEATURE_BITS ((NCAPINTS + NBUGINTS) * sizeof(u32) * 8)
 
-static void do_clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
+void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
 {
 	DECLARE_BITMAP(disable, MAX_FEATURE_BITS);
 	const struct cpuid_dep *d;
@@ -129,12 +127,7 @@ static void do_clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
 	} while (changed);
 }
 
-void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
-{
-	do_clear_cpu_cap(c, feature);
-}
-
 void setup_clear_cpu_cap(unsigned int feature)
 {
-	do_clear_cpu_cap(NULL, feature);
+	clear_cpu_cap(&boot_cpu_data, feature);
 }
-- 
2.26.3