x86/pconfig: Detect PCONFIG targets (be7825c1) · Commits · 戴 / test

arch/x86/include/asm/intel_pconfig.h

0 → 100644

+15 −0

Original line number	Diff line number	Diff line
		#ifndef _ASM_X86_INTEL_PCONFIG_H
		#define _ASM_X86_INTEL_PCONFIG_H

		#include <asm/asm.h>
		#include <asm/processor.h>

		enum pconfig_target {
		INVALID_TARGET = 0,
		MKTME_TARGET = 1,
		PCONFIG_TARGET_NR
		};

		int pconfig_target_supported(enum pconfig_target target);

		#endif /* _ASM_X86_INTEL_PCONFIG_H */

arch/x86/kernel/cpu/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -28,7 +28,7 @@ obj-y += cpuid-deps.o
		obj-$(CONFIG_PROC_FS) += proc.o
		obj-$(CONFIG_X86_FEATURE_NAMES) += capflags.o powerflags.o

		obj-$(CONFIG_CPU_SUP_INTEL) += intel.o
		obj-$(CONFIG_CPU_SUP_INTEL) += intel.o intel_pconfig.o
		obj-$(CONFIG_CPU_SUP_AMD) += amd.o
		obj-$(CONFIG_CPU_SUP_CYRIX_32) += cyrix.o
		obj-$(CONFIG_CPU_SUP_CENTAUR) += centaur.o

arch/x86/kernel/cpu/intel_pconfig.c

0 → 100644

+82 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		/*
		* Intel PCONFIG instruction support.
		*
		* Copyright (C) 2017 Intel Corporation
		*
		* Author:
		* Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
		*/

		#include <asm/cpufeature.h>
		#include <asm/intel_pconfig.h>

		#define PCONFIG_CPUID 0x1b

		#define PCONFIG_CPUID_SUBLEAF_MASK ((1 << 12) - 1)

		/* Subleaf type (EAX) for PCONFIG CPUID leaf (0x1B) */
		enum {
		PCONFIG_CPUID_SUBLEAF_INVALID = 0,
		PCONFIG_CPUID_SUBLEAF_TARGETID = 1,
		};

		/* Bitmask of supported targets */
		static u64 targets_supported __read_mostly;

		int pconfig_target_supported(enum pconfig_target target)
		{
		/*
		* We would need to re-think the implementation once we get > 64
		* PCONFIG targets. Spec allows up to 2^32 targets.
		*/
		BUILD_BUG_ON(PCONFIG_TARGET_NR >= 64);

		if (WARN_ON_ONCE(target >= 64))
		return 0;
		return targets_supported & (1ULL << target);
		}

		static int __init intel_pconfig_init(void)
		{
		int subleaf;

		if (!boot_cpu_has(X86_FEATURE_PCONFIG))
		return 0;

		/*
		* Scan subleafs of PCONFIG CPUID leaf.
		*
		* Subleafs of the same type need not to be consecutive.
		*
		* Stop on the first invalid subleaf type. All subleafs after the first
		* invalid are invalid too.
		*/
		for (subleaf = 0; subleaf < INT_MAX; subleaf++) {
		struct cpuid_regs regs;

		cpuid_count(PCONFIG_CPUID, subleaf,
		&regs.eax, &regs.ebx, &regs.ecx, &regs.edx);

		switch (regs.eax & PCONFIG_CPUID_SUBLEAF_MASK) {
		case PCONFIG_CPUID_SUBLEAF_INVALID:
		/* Stop on the first invalid subleaf */
		goto out;
		case PCONFIG_CPUID_SUBLEAF_TARGETID:
		/* Mark supported PCONFIG targets */
		if (regs.ebx < 64)
		targets_supported \|= (1ULL << regs.ebx);
		if (regs.ecx < 64)
		targets_supported \|= (1ULL << regs.ecx);
		if (regs.edx < 64)
		targets_supported \|= (1ULL << regs.edx);
		break;
		default:
		/* Unknown CPUID.PCONFIG subleaf: ignore */
		break;
		}
		}
		out:
		return 0;
		}
		arch_initcall(intel_pconfig_init);

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