linux-kernel - [PATCH v3 24/44] x86/cpu: Use parsed CPUID(0x0)

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Message-ID: <20250612234010.572636-25-darwi@linutronix.de>
Date: Fri, 13 Jun 2025 01:39:50 +0200
From: "Ahmed S. Darwish" <darwi@...utronix.de>
To: Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Thomas Gleixner <tglx@...utronix.de>,
	Andrew Cooper <andrew.cooper3@...rix.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Sean Christopherson <seanjc@...gle.com>,
	Sohil Mehta <sohil.mehta@...el.com>,
	Ard Biesheuvel <ardb@...nel.org>,
	John Ogness <john.ogness@...utronix.de>,
	x86@...nel.org,
	x86-cpuid@...ts.linux.dev,
	LKML <linux-kernel@...r.kernel.org>,
	"Ahmed S. Darwish" <darwi@...utronix.de>
Subject: [PATCH v3 24/44] x86/cpu: Use parsed CPUID(0x0)

Use parsed CPUID(0x0) access instead of a direct CPUID query.

Signed-off-by: Ahmed S. Darwish <darwi@...utronix.de>
---
 arch/x86/kernel/cpu/common.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 8aa3ba269c0b..234d0f5de39e 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -895,11 +895,12 @@ void get_cpu_vendor(struct cpuinfo_x86 *c)
 
 void cpu_detect(struct cpuinfo_x86 *c)
 {
-	/* Get vendor name */
-	cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
-	      (unsigned int *)&c->x86_vendor_id[0],
-	      (unsigned int *)&c->x86_vendor_id[8],
-	      (unsigned int *)&c->x86_vendor_id[4]);
+	const struct leaf_0x0_0 *l0 = cpuid_leaf(c, 0x0);
+
+	c->cpuid_level = l0->max_std_leaf;
+	*(u32 *)&c->x86_vendor_id[0] = l0->cpu_vendorid_0;
+	*(u32 *)&c->x86_vendor_id[4] = l0->cpu_vendorid_1;
+	*(u32 *)&c->x86_vendor_id[8] = l0->cpu_vendorid_2;
 
 	c->x86 = 4;
 	/* Intel-defined flags: level 0x00000001 */
-- 
2.49.0