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Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
-rw-r--r--arch/x86/kernel/cpu/intel.c54
1 files changed, 36 insertions, 18 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index bf08d4508ecb..a19a680542ce 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -1119,35 +1119,53 @@ void switch_to_sld(unsigned long tifn)
sld_update_msr(!(tifn & _TIF_SLD));
}
-#define SPLIT_LOCK_CPU(model) {X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY}
-
/*
- * The following processors have the split lock detection feature. But
- * since they don't have the IA32_CORE_CAPABILITIES MSR, the feature cannot
- * be enumerated. Enable it by family and model matching on these
- * processors.
+ * Bits in the IA32_CORE_CAPABILITIES are not architectural, so they should
+ * only be trusted if it is confirmed that a CPU model implements a
+ * specific feature at a particular bit position.
+ *
+ * The possible driver data field values:
+ *
+ * - 0: CPU models that are known to have the per-core split-lock detection
+ * feature even though they do not enumerate IA32_CORE_CAPABILITIES.
+ *
+ * - 1: CPU models which may enumerate IA32_CORE_CAPABILITIES and if so use
+ * bit 5 to enumerate the per-core split-lock detection feature.
*/
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),
+ X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X, 0),
+ X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_L, 0),
+ X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT, 1),
+ X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_D, 1),
+ X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_L, 1),
{}
};
void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c)
{
- u64 ia32_core_caps = 0;
+ const struct x86_cpu_id *m;
+ u64 ia32_core_caps;
+
+ if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
+ return;
- if (c->x86_vendor != X86_VENDOR_INTEL)
+ m = x86_match_cpu(split_lock_cpu_ids);
+ if (!m)
return;
- if (cpu_has(c, X86_FEATURE_CORE_CAPABILITIES)) {
- /* Enumerate features reported in IA32_CORE_CAPABILITIES MSR. */
+
+ switch (m->driver_data) {
+ case 0:
+ break;
+ case 1:
+ if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES))
+ return;
rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps);
- } else if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
- /* Enumerate split lock detection by family and model. */
- if (x86_match_cpu(split_lock_cpu_ids))
- ia32_core_caps |= MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT;
+ if (!(ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT))
+ return;
+ break;
+ default:
+ return;
}
- if (ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT)
- split_lock_setup();
+ split_lock_setup();
}