mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-25 05:04:09 +08:00
be7825c19b
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: Kirill 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.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
83 lines
1.9 KiB
C
83 lines
1.9 KiB
C
// 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,
|
|
®s.eax, ®s.ebx, ®s.ecx, ®s.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);
|