[PATCH v9 06/17] x86/split_lock: Enumerate split lock detection by MSR_IA32_CORE_CAP

Fenghua Yu
2019-06-18T22:52:20Z

Bits in MSR_IA32_CORE_CAP enumerate a few features that are not
enumerated through CPUID. Currently bit 5 is defined to enumerate
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 MSR_IA32_CORE_CAP itself is enumerated by
CPUID.(EAX=0x7,ECX=0):EDX[30].

Signed-off-by: Fenghua Yu <fenghua.yu@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/cpuid-deps.c | 79 +++++++++++++++---------------
arch/x86/kernel/cpu/intel.c | 22 +++++++++
5 files changed, 70 insertions(+), 39 deletions(-)

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 c6e888688a13..5e3759b7c5b7 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -221,6 +221,7 @@
#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 ed2b81b437e0..9aa91140024f 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1119,6 +1119,8 @@ 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/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index 2c0bd38a44ab..3d633f67fbd7 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -20,45 +20,46 @@ struct cpuid_dep {
* but it's difficult to tell that to the init reference checker.
*/
static const struct cpuid_dep cpuid_deps[] = {
- { X86_FEATURE_XSAVEOPT, X86_FEATURE_XSAVE },
- { X86_FEATURE_XSAVEC, X86_FEATURE_XSAVE },
- { X86_FEATURE_XSAVES, X86_FEATURE_XSAVE },
- { X86_FEATURE_AVX, X86_FEATURE_XSAVE },
- { X86_FEATURE_PKU, X86_FEATURE_XSAVE },
- { X86_FEATURE_MPX, X86_FEATURE_XSAVE },
- { X86_FEATURE_XGETBV1, X86_FEATURE_XSAVE },
- { X86_FEATURE_FXSR_OPT, X86_FEATURE_FXSR },
- { X86_FEATURE_XMM, X86_FEATURE_FXSR },
- { X86_FEATURE_XMM2, X86_FEATURE_XMM },
- { X86_FEATURE_XMM3, X86_FEATURE_XMM2 },
- { X86_FEATURE_XMM4_1, X86_FEATURE_XMM2 },
- { X86_FEATURE_XMM4_2, X86_FEATURE_XMM2 },
- { X86_FEATURE_XMM3, X86_FEATURE_XMM2 },
- { X86_FEATURE_PCLMULQDQ, X86_FEATURE_XMM2 },
- { X86_FEATURE_SSSE3, X86_FEATURE_XMM2, },
- { X86_FEATURE_F16C, X86_FEATURE_XMM2, },
- { X86_FEATURE_AES, X86_FEATURE_XMM2 },
- { X86_FEATURE_SHA_NI, X86_FEATURE_XMM2 },
- { X86_FEATURE_FMA, X86_FEATURE_AVX },
- { X86_FEATURE_AVX2, X86_FEATURE_AVX, },
- { X86_FEATURE_AVX512F, X86_FEATURE_AVX, },
- { X86_FEATURE_AVX512IFMA, X86_FEATURE_AVX512F },
- { X86_FEATURE_AVX512PF, X86_FEATURE_AVX512F },
- { X86_FEATURE_AVX512ER, X86_FEATURE_AVX512F },
- { X86_FEATURE_AVX512CD, X86_FEATURE_AVX512F },
- { X86_FEATURE_AVX512DQ, X86_FEATURE_AVX512F },
- { X86_FEATURE_AVX512BW, X86_FEATURE_AVX512F },
- { X86_FEATURE_AVX512VL, X86_FEATURE_AVX512F },
- { X86_FEATURE_AVX512VBMI, X86_FEATURE_AVX512F },
- { X86_FEATURE_AVX512_VBMI2, X86_FEATURE_AVX512VL },
- { X86_FEATURE_GFNI, X86_FEATURE_AVX512VL },
- { X86_FEATURE_VAES, X86_FEATURE_AVX512VL },
- { X86_FEATURE_VPCLMULQDQ, X86_FEATURE_AVX512VL },
- { X86_FEATURE_AVX512_VNNI, X86_FEATURE_AVX512VL },
- { X86_FEATURE_AVX512_BITALG, X86_FEATURE_AVX512VL },
- { X86_FEATURE_AVX512_4VNNIW, X86_FEATURE_AVX512F },
- { X86_FEATURE_AVX512_4FMAPS, X86_FEATURE_AVX512F },
- { X86_FEATURE_AVX512_VPOPCNTDQ, X86_FEATURE_AVX512F },
+ { X86_FEATURE_XSAVEOPT, X86_FEATURE_XSAVE },
+ { X86_FEATURE_XSAVEC, X86_FEATURE_XSAVE },
+ { X86_FEATURE_XSAVES, X86_FEATURE_XSAVE },
+ { X86_FEATURE_AVX, X86_FEATURE_XSAVE },
+ { X86_FEATURE_PKU, X86_FEATURE_XSAVE },
+ { X86_FEATURE_MPX, X86_FEATURE_XSAVE },
+ { X86_FEATURE_XGETBV1, X86_FEATURE_XSAVE },
+ { X86_FEATURE_FXSR_OPT, X86_FEATURE_FXSR },
+ { X86_FEATURE_XMM, X86_FEATURE_FXSR },
+ { X86_FEATURE_XMM2, X86_FEATURE_XMM },
+ { X86_FEATURE_XMM3, X86_FEATURE_XMM2 },
+ { X86_FEATURE_XMM4_1, X86_FEATURE_XMM2 },
+ { X86_FEATURE_XMM4_2, X86_FEATURE_XMM2 },
+ { X86_FEATURE_XMM3, X86_FEATURE_XMM2 },
+ { X86_FEATURE_PCLMULQDQ, X86_FEATURE_XMM2 },
+ { X86_FEATURE_SSSE3, X86_FEATURE_XMM2, },
+ { X86_FEATURE_F16C, X86_FEATURE_XMM2, },
+ { X86_FEATURE_AES, X86_FEATURE_XMM2 },
+ { X86_FEATURE_SHA_NI, X86_FEATURE_XMM2 },
+ { X86_FEATURE_FMA, X86_FEATURE_AVX },
+ { X86_FEATURE_AVX2, X86_FEATURE_AVX, },
+ { X86_FEATURE_AVX512F, X86_FEATURE_AVX, },
+ { X86_FEATURE_AVX512IFMA, X86_FEATURE_AVX512F },
+ { X86_FEATURE_AVX512PF, X86_FEATURE_AVX512F },
+ { X86_FEATURE_AVX512ER, X86_FEATURE_AVX512F },
+ { X86_FEATURE_AVX512CD, X86_FEATURE_AVX512F },
+ { X86_FEATURE_AVX512DQ, X86_FEATURE_AVX512F },
+ { X86_FEATURE_AVX512BW, X86_FEATURE_AVX512F },
+ { X86_FEATURE_AVX512VL, X86_FEATURE_AVX512F },
+ { X86_FEATURE_AVX512VBMI, X86_FEATURE_AVX512F },
+ { X86_FEATURE_AVX512_VBMI2, X86_FEATURE_AVX512VL },
+ { X86_FEATURE_GFNI, X86_FEATURE_AVX512VL },
+ { X86_FEATURE_VAES, X86_FEATURE_AVX512VL },
+ { X86_FEATURE_VPCLMULQDQ, X86_FEATURE_AVX512VL },
+ { X86_FEATURE_AVX512_VNNI, X86_FEATURE_AVX512VL },
+ { X86_FEATURE_AVX512_BITALG, X86_FEATURE_AVX512VL },
+ { X86_FEATURE_AVX512_4VNNIW, X86_FEATURE_AVX512F },
+ { X86_FEATURE_AVX512_4FMAPS, X86_FEATURE_AVX512F },
+ { X86_FEATURE_AVX512_VPOPCNTDQ, X86_FEATURE_AVX512F },
+ { X86_FEATURE_SPLIT_LOCK_DETECT, X86_FEATURE_CORE_CAPABILITY},
{}
};

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index f17c1a714779..d63a4ba203e1 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -995,3 +995,25 @@ 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_cap = 0;
+
+ if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITY))
+ return;
+
+ /*
+ * If MSR_IA32_CORE_CAP exists, enumerate features that are
+ * reported in the MSR.
+ */
+ rdmsrl(MSR_IA32_CORE_CAP, ia32_core_cap);
+
+ if (ia32_core_cap & MSR_IA32_CORE_CAP_SPLIT_LOCK_DETECT)
+ split_lock_setup();
+}
--
2.19.1