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Message-Id: <1574297603-198156-5-git-send-email-fenghua.yu@intel.com>
Date: Wed, 20 Nov 2019 16:53:21 -0800
From: Fenghua Yu <fenghua.yu@...el.com>
To: "Thomas Gleixner" <tglx@...utronix.de>,
"Ingo Molnar" <mingo@...hat.com>, "Borislav Petkov" <bp@...en8.de>,
"H Peter Anvin" <hpa@...or.com>,
"Peter Zijlstra" <peterz@...radead.org>,
"Tony Luck" <tony.luck@...el.com>,
"Ashok Raj" <ashok.raj@...el.com>,
"Ravi V Shankar" <ravi.v.shankar@...el.com>
Cc: "linux-kernel" <linux-kernel@...r.kernel.org>,
"x86" <x86@...nel.org>, Fenghua Yu <fenghua.yu@...el.com>
Subject: [PATCH v10 4/6] x86/split_lock: Enumerate split lock detection if the IA32_CORE_CAPABILITIES MSR is not supported
Architecturally the split lock detection feature is enumerated by
IA32_CORE_CAPABILITIES MSR and future CPU models will indicate presence
of the feature by setting bit 5. But the feature is present in a few
older models where split lock detection is enumerated by the CPU models.
Use a "x86_cpu_id" table to list the older CPU models with the feature.
Signed-off-by: Fenghua Yu <fenghua.yu@...el.com>
Reviewed-by: Tony Luck <tony.luck@...el.com>
---
arch/x86/kernel/cpu/intel.c | 27 ++++++++++++++++++++++-----
1 file changed, 22 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index ce87e2c68767..2614616fb6d3 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -19,6 +19,7 @@
#include <asm/microcode_intel.h>
#include <asm/hwcap2.h>
#include <asm/elf.h>
+#include <asm/cpu_device_id.h>
#ifdef CONFIG_X86_64
#include <linux/topology.h>
@@ -1034,15 +1035,31 @@ static void __init split_lock_setup(void)
setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT);
}
+#define SPLIT_LOCK_CPU(model) {X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY}
+
+/*
+ * The following processors have split lock detection feature. But since they
+ * don't have MSR IA32_CORE_CAPABILITIES, the feature cannot be enumerated by
+ * the MSR. So enumerate the feature by family and model on these processors.
+ */
+static const struct x86_cpu_id split_lock_cpu_ids[] __initconst = {
+ SPLIT_LOCK_CPU(INTEL_FAM6_ICELAKE_X),
+ SPLIT_LOCK_CPU(INTEL_FAM6_ICELAKE_L),
+ {}
+};
+
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 (cpu_has(c, X86_FEATURE_CORE_CAPABILITIES)) {
+ /* Enumerate features reported in IA32_CORE_CAPABILITIES MSR. */
+ rdmsrl(MSR_IA32_CORE_CAPABILITIES, ia32_core_caps);
+ } else {
+ /* Enumerate split lock detection by family and model. */
+ if (x86_match_cpu(split_lock_cpu_ids))
+ ia32_core_caps |= MSR_IA32_CORE_CAPABILITIES_SPLIT_LOCK_DETECT;
+ }
if (ia32_core_caps & MSR_IA32_CORE_CAPABILITIES_SPLIT_LOCK_DETECT)
split_lock_setup();
--
2.19.1
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