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From: Fenghua Yu <fenghua.yu@intel.com>
To: "Thomas Gleixner" <tglx@linutronix.de>,
	"Ingo Molnar" <mingo@redhat.com>,
	"Borislav Petkov" <bp@alien8.de>, "H Peter Anvin" <hpa@zytor.com>,
	"Peter Zijlstra" <peterz@infradead.org>,
	"Tony Luck" <tony.luck@intel.com>,
	"Ashok Raj" <ashok.raj@intel.com>,
	"Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "linux-kernel" <linux-kernel@vger.kernel.org>,
	"x86" <x86@kernel.org>, Fenghua Yu <fenghua.yu@intel.com>
Subject: [PATCH v10 3/6] x86/split_lock: Enumerate split lock detection by the IA32_CORE_CAPABILITIES MSR
Date: Wed, 20 Nov 2019 16:53:20 -0800	[thread overview]
Message-ID: <1574297603-198156-4-git-send-email-fenghua.yu@intel.com> (raw)
In-Reply-To: <1574297603-198156-1-git-send-email-fenghua.yu@intel.com>

Bits in the IA32_CORE_CAPABILITIES MSR enumerate a few features that are
not enumerated through CPUID. Currently bit 5 is defined to enumerate
the feature of split lock detection. All other bits are reserved now.

When bit 5 is 1, the feature is supported and feature bit
X86_FEATURE_SPLIT_LOCK_DETECT is set. Otherwise, the feature is not
available.

The flag shown in /proc/cpuinfo is "split_lock_detect".

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
---
 arch/x86/include/asm/cpu.h         |  5 +++++
 arch/x86/include/asm/cpufeatures.h |  1 +
 arch/x86/kernel/cpu/common.c       |  2 ++
 arch/x86/kernel/cpu/intel.c        | 19 +++++++++++++++++++
 4 files changed, 27 insertions(+)

diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index adc6cc86b062..4e03f53fc079 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -40,4 +40,9 @@ int mwait_usable(const struct cpuinfo_x86 *);
 unsigned int x86_family(unsigned int sig);
 unsigned int x86_model(unsigned int sig);
 unsigned int x86_stepping(unsigned int sig);
+#ifdef CONFIG_CPU_SUP_INTEL
+void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c);
+#else
+static inline void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c) {}
+#endif
 #endif /* _ASM_X86_CPU_H */
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index d708a1f83f40..92be003c02ba 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -220,6 +220,7 @@
 #define X86_FEATURE_ZEN			( 7*32+28) /* "" CPU is AMD family 0x17 (Zen) */
 #define X86_FEATURE_L1TF_PTEINV		( 7*32+29) /* "" L1TF workaround PTE inversion */
 #define X86_FEATURE_IBRS_ENHANCED	( 7*32+30) /* Enhanced IBRS */
+#define X86_FEATURE_SPLIT_LOCK_DETECT	( 7*32+31) /* #AC for split lock */
 
 /* Virtualization flags: Linux defined, word 8 */
 #define X86_FEATURE_TPR_SHADOW		( 8*32+ 0) /* Intel TPR Shadow */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index fffe21945374..2ee5fd49266f 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1235,6 +1235,8 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
 
 	cpu_set_bug_bits(c);
 
+	cpu_set_core_cap_bits(c);
+
 	fpu__init_system(c);
 
 #ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 11d5c5950e2d..ce87e2c68767 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -1028,3 +1028,22 @@ static const struct cpu_dev intel_cpu_dev = {
 };
 
 cpu_dev_register(intel_cpu_dev);
+
+static void __init split_lock_setup(void)
+{
+	setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT);
+}
+
+void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c)
+{
+	u64 ia32_core_caps = 0;
+
+	if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES))
+		return;
+
+	/* Enumerate features reported in IA32_CORE_CAPABILITIES MSR. */
+	rdmsrl(MSR_IA32_CORE_CAPABILITIES, ia32_core_caps);
+
+	if (ia32_core_caps & MSR_IA32_CORE_CAPABILITIES_SPLIT_LOCK_DETECT)
+		split_lock_setup();
+}
-- 
2.19.1


  parent reply	other threads:[~2019-11-21  1:45 UTC|newest]

Thread overview: 145+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-21  0:53 [PATCH v10 0/6] Enable split lock detection for real time and debug Fenghua Yu
2019-11-21  0:53 ` [PATCH v10 1/6] x86/msr-index: Add two new MSRs Fenghua Yu
2019-11-21  0:53 ` [PATCH v10 2/6] x86/cpufeatures: Enumerate the IA32_CORE_CAPABILITIES MSR Fenghua Yu
2019-11-21  0:53 ` Fenghua Yu [this message]
2019-11-21  0:53 ` [PATCH v10 4/6] x86/split_lock: Enumerate split lock detection if the IA32_CORE_CAPABILITIES MSR is not supported Fenghua Yu
2019-11-21 22:07   ` Andy Lutomirski
2019-11-22  0:37     ` Fenghua Yu
2019-11-22  2:13       ` Andy Lutomirski
2019-11-22  9:46         ` Peter Zijlstra
2019-11-21  0:53 ` [PATCH v10 5/6] x86/split_lock: Handle #AC exception for split lock Fenghua Yu
2019-11-21 22:10   ` Andy Lutomirski
2019-11-21 23:14     ` Fenghua Yu
2019-11-21 23:12       ` Andy Lutomirski
2019-11-21  0:53 ` [PATCH v10 6/6] x86/split_lock: Enable split lock detection by kernel parameter Fenghua Yu
2019-11-21  6:04   ` Ingo Molnar
2019-11-21 13:01     ` Peter Zijlstra
2019-11-21 13:15       ` Peter Zijlstra
2019-11-21 21:51         ` Luck, Tony
2019-11-21 22:24           ` Andy Lutomirski
2019-11-21 22:29             ` Luck, Tony
2019-11-21 23:18               ` Andy Lutomirski
2019-11-21 23:53                 ` Fenghua Yu
2019-11-22  1:52                   ` Sean Christopherson
2019-11-22  2:21                     ` Andy Lutomirski
2019-11-22  2:39                       ` Xiaoyao Li
2019-11-22  2:57                         ` Andy Lutomirski
2019-11-21 23:55                 ` Luck, Tony
2019-11-22  0:55             ` Luck, Tony
2019-11-22 10:08           ` Peter Zijlstra
2019-11-21 16:14       ` Fenghua Yu
2019-11-21 17:14         ` Ingo Molnar
2019-11-21 17:35         ` Peter Zijlstra
2019-11-21 17:12       ` Ingo Molnar
2019-11-21 17:34         ` Luck, Tony
2019-11-22 10:51           ` Peter Zijlstra
2019-11-22 15:27             ` Peter Zijlstra
2019-11-22 17:22               ` Luck, Tony
2019-11-22 20:23                 ` Peter Zijlstra
2019-11-22 18:02               ` Luck, Tony
2019-11-22 20:23                 ` Peter Zijlstra
2019-11-22 20:42                   ` Fenghua Yu
2019-11-22 21:25                     ` Andy Lutomirski
2019-12-12  8:57                       ` Peter Zijlstra
2019-12-12 18:52                         ` Luck, Tony
2019-12-12 19:46                           ` Luck, Tony
2019-12-12 20:01                             ` Andy Lutomirski
2019-12-16 16:21                               ` David Laight
2019-11-22 18:44               ` Sean Christopherson
2019-11-22 20:30                 ` Peter Zijlstra
2019-11-23  0:30               ` Luck, Tony
2019-11-25 16:13                 ` Sean Christopherson
2019-12-02 18:20                   ` Luck, Tony
2019-12-12  8:59                   ` Peter Zijlstra
2020-01-10 19:24                     ` [PATCH v11] x86/split_lock: Enable split lock detection by kernel Luck, Tony
2020-01-14  5:55                       ` Sean Christopherson
2020-01-15 22:27                         ` Luck, Tony
2020-01-15 22:57                           ` Sean Christopherson
2020-01-15 23:48                             ` Luck, Tony
2020-01-22 18:55                             ` [PATCH v12] " Luck, Tony
2020-01-22 19:04                               ` Borislav Petkov
2020-01-22 20:03                                 ` Luck, Tony
2020-01-22 20:55                                   ` Borislav Petkov
2020-01-22 22:42                               ` Arvind Sankar
2020-01-22 22:52                                 ` Arvind Sankar
2020-01-22 23:24                                 ` Luck, Tony
2020-01-23  0:45                                   ` Arvind Sankar
2020-01-23  1:23                                     ` Luck, Tony
2020-01-23  4:21                                       ` Arvind Sankar
2020-01-23 17:15                                         ` Luck, Tony
2020-01-23  3:53                                     ` [PATCH v13] " Luck, Tony
2020-01-23  4:45                                       ` Arvind Sankar
2020-01-23 23:16                                         ` [PATCH v14] " Luck, Tony
2020-01-24 21:36                                           ` Thomas Gleixner
2020-01-25  2:47                                             ` [PATCH v15] " Luck, Tony
2020-01-25 10:44                                               ` Borislav Petkov
2020-01-25 19:55                                                 ` Luck, Tony
2020-01-25 20:12                                                   ` Peter Zijlstra
2020-01-25 20:33                                                     ` Borislav Petkov
2020-01-25 21:42                                                       ` Luck, Tony
2020-01-25 22:17                                                         ` Borislav Petkov
2020-01-25 20:29                                                   ` Borislav Petkov
2020-01-25 13:41                                               ` Thomas Gleixner
2020-01-25 22:07                                                 ` [PATCH v16] " Luck, Tony
2020-01-25 22:43                                                   ` Mark D Rustad
2020-01-25 23:10                                                     ` Luck, Tony
2020-01-26 17:27                                                       ` Mark D Rustad
2020-01-26 20:05                                                         ` [PATCH v17] " Luck, Tony
2020-01-29 12:31                                                           ` Thomas Gleixner
2020-01-29 15:24                                                           ` [tip: x86/cpu] " tip-bot2 for Peter Zijlstra (Intel)
2020-02-03 20:41                                                           ` [PATCH v17] " Sean Christopherson
2020-02-06  0:49                                                             ` [PATCH] x86/split_lock: Avoid runtime reads of the TEST_CTRL MSR Luck, Tony
2020-02-06  1:18                                                               ` Andy Lutomirski
2020-02-06 16:46                                                                 ` Luck, Tony
2020-02-06 19:37                                                                   ` Andy Lutomirski
2020-03-03 19:22                                                                     ` Sean Christopherson
2020-02-04  0:04                                                           ` [PATCH v17] x86/split_lock: Enable split lock detection by kernel Sean Christopherson
2020-02-04 12:52                                                             ` Thomas Gleixner
2020-01-26  0:34                                                   ` [PATCH v16] " Andy Lutomirski
2020-01-26 20:01                                                     ` Luck, Tony
2020-01-25 21:25                                               ` [PATCH v15] " Arvind Sankar
2020-01-25 21:50                                                 ` Luck, Tony
2020-01-25 23:51                                                   ` Arvind Sankar
2020-01-26  2:52                                                     ` Luck, Tony
2020-01-27  2:05                                                       ` Tony Luck
2020-01-27  8:04                                                   ` Peter Zijlstra
2020-01-27  8:36                                                     ` Peter Zijlstra
2020-01-27 17:35                                                     ` Luck, Tony
2020-01-27  8:02                                                 ` Peter Zijlstra
2019-12-13  0:09               ` [PATCH v11] x86/split_lock: Enable split lock detection by kernel parameter Tony Luck
2019-12-13  0:16                 ` Luck, Tony
2019-11-21 17:43         ` [PATCH v10 6/6] " David Laight
2019-11-21 17:51           ` Andy Lutomirski
2019-11-21 18:53             ` Fenghua Yu
2019-11-21 19:01               ` Andy Lutomirski
2019-11-21 20:25                 ` Fenghua Yu
2019-11-21 20:19                   ` Peter Zijlstra
2019-11-21 19:46               ` Peter Zijlstra
2019-11-21 20:25               ` Peter Zijlstra
2019-11-21 21:22                 ` Andy Lutomirski
2019-11-22  9:25                   ` Peter Zijlstra
2019-11-22 17:48                     ` Luck, Tony
2019-11-22 20:31                       ` Peter Zijlstra
2019-11-22 21:23                         ` Andy Lutomirski
2019-12-11 17:52                           ` Peter Zijlstra
2019-12-11 18:12                             ` Andy Lutomirski
2019-12-11 22:34                               ` Peter Zijlstra
2019-12-12 19:40                                 ` Andy Lutomirski
2019-12-16  9:59                                   ` David Laight
2019-12-16 17:22                                     ` Andy Lutomirski
2019-12-16 17:45                                       ` David Laight
2019-12-16 18:06                                         ` Andy Lutomirski
2019-12-17 10:03                                           ` David Laight
2019-12-11 18:44                             ` Luck, Tony
2019-12-11 22:39                               ` Peter Zijlstra
2019-12-12 10:36                                 ` David Laight
2019-12-12 13:04                                   ` Peter Zijlstra
2019-12-12 16:02                                     ` Andy Lutomirski
2019-12-12 16:23                                       ` David Laight
2019-12-12 16:29                                     ` David Laight
2019-11-21 19:56             ` Peter Zijlstra
2019-11-21 21:01               ` Andy Lutomirski
2019-11-22  9:36                 ` Peter Zijlstra
2019-11-22  9:46             ` David Laight
2019-11-22 20:32               ` Peter Zijlstra
2019-11-21  8:00   ` Peter Zijlstra

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