From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 487EC6B000A for ; Mon, 5 Mar 2018 11:26:25 -0500 (EST) Received: by mail-pf0-f199.google.com with SMTP id j12so6671173pff.18 for ; Mon, 05 Mar 2018 08:26:25 -0800 (PST) Received: from mga09.intel.com (mga09.intel.com. [134.134.136.24]) by mx.google.com with ESMTPS id z21si10604935pfa.33.2018.03.05.08.26.23 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 05 Mar 2018 08:26:23 -0800 (PST) From: "Kirill A. Shutemov" Subject: [RFC, PATCH 04/22] x86/pconfig: Detect PCONFIG targets Date: Mon, 5 Mar 2018 19:25:52 +0300 Message-Id: <20180305162610.37510-5-kirill.shutemov@linux.intel.com> In-Reply-To: <20180305162610.37510-1-kirill.shutemov@linux.intel.com> References: <20180305162610.37510-1-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Ingo Molnar , x86@kernel.org, Thomas Gleixner , "H. Peter Anvin" , Tom Lendacky Cc: Dave Hansen , Kai Huang , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" 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 --- arch/x86/include/asm/intel_pconfig.h | 15 +++++++ arch/x86/kernel/cpu/Makefile | 2 +- arch/x86/kernel/cpu/intel_pconfig.c | 82 ++++++++++++++++++++++++++++++++++++ 3 files changed, 98 insertions(+), 1 deletion(-) create mode 100644 arch/x86/include/asm/intel_pconfig.h create mode 100644 arch/x86/kernel/cpu/intel_pconfig.c diff --git a/arch/x86/include/asm/intel_pconfig.h b/arch/x86/include/asm/intel_pconfig.h new file mode 100644 index 000000000000..fb7a37c3798b --- /dev/null +++ b/arch/x86/include/asm/intel_pconfig.h @@ -0,0 +1,15 @@ +#ifndef _ASM_X86_INTEL_PCONFIG_H +#define _ASM_X86_INTEL_PCONFIG_H + +#include +#include + +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 */ diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index 570e8bb1f386..a66229f51b12 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile @@ -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 diff --git a/arch/x86/kernel/cpu/intel_pconfig.c b/arch/x86/kernel/cpu/intel_pconfig.c new file mode 100644 index 000000000000..0771a905b286 --- /dev/null +++ b/arch/x86/kernel/cpu/intel_pconfig.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Intel PCONFIG instruction support. + * + * Copyright (C) 2017 Intel Corporation + * + * Author: + * Kirill A. Shutemov + */ + +#include +#include + +#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); -- 2.16.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org