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From:   Maxim Levitsky <mlevitsk@redhat.com>
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        Josh Poimboeuf <jpoimboe@kernel.org>,
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        Peter Zijlstra <peterz@infradead.org>,
        Maxim Levitsky <mlevitsk@redhat.com>,
        x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
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        linux-crypto@vger.kernel.org (open list:CRYPTO API)
Subject: [PATCH v2 2/5] x86/cpuid: refactor setup_clear_cpu_cap()/clear_cpu_cap()
Date:   Mon, 18 Jul 2022 17:11:20 +0300
Message-Id: <20220718141123.136106-3-mlevitsk@redhat.com>
In-Reply-To: <20220718141123.136106-1-mlevitsk@redhat.com>
References: <20220718141123.136106-1-mlevitsk@redhat.com>
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Currently setup_clear_cpu_cap passes NULL 'struct cpuinfo_x86*'
to clear_cpu_cap to indicate that capability should be cleared from boot_cpu_data.

Later that is used in clear_feature to do recursive call to
clear_cpu_cap together with clearing the feature bit from 'cpu_caps_cleared'

Remove that code and just call the do_clear_cpu_cap on boot_cpu_data directly
from the setup_clear_cpu_cap.

The only functional change this introduces is that now calling clear_cpu_cap
explicitly on boot_cpu_data also sets the bits in cpu_caps_cleared,
which is the only thing that makes sense anyway.

All callers of both functions were checked for this and fixed.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.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);
 }
-- 
2.34.3