Commit be7825c1 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Ingo Molnar

x86/pconfig: Detect PCONFIG targets

Intel PCONFIG targets are enumerated via new CPUID leaf 0x1b. This patch
detects all supported targets of PCONFIG and implements helper to check
if the target is supported.
Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kai Huang <kai.huang@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180305162610.37510-5-kirill.shutemov@linux.intel.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent cb06d8e3
#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 */
......@@ -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
......
// 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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