1 files changed, 63 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
new file mode 100644
index 000000000000..34b4dad6f0b8
--- /dev/null
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -0,0 +1,63 @@
+/*
+ *      Routines to indentify additional cpu features that are scattered in
+ *      cpuid space.
+ */
+#include <linux/cpu.h>
+
+#include <asm/pat.h>
+#include <asm/processor.h>
+
+#include <asm/apic.h>
+
+struct cpuid_bit {
+        u16 feature;
+        u8 reg;
+        u8 bit;
+        u32 level;
+        u32 sub_leaf;
+};
+
+enum cpuid_regs {
+        CR_EAX = 0,
+        CR_ECX,
+        CR_EDX,
+        CR_EBX
+};
+
+void __cpuinit init_scattered_cpuid_features(struct cpuinfo_x86 *c)
+{
+        u32 max_level;
+        u32 regs[4];
+        const struct cpuid_bit *cb;
+
+        static const struct cpuid_bit __cpuinitconst cpuid_bits[] = {
+                { X86_FEATURE_IDA,              CR_EAX, 1, 0x00000006, 0 },
+                { X86_FEATURE_ARAT,             CR_EAX, 2, 0x00000006, 0 },
+                { X86_FEATURE_PLN,              CR_EAX, 4, 0x00000006, 0 },
+                { X86_FEATURE_PTS,              CR_EAX, 6, 0x00000006, 0 },
+                { X86_FEATURE_APERFMPERF,       CR_ECX, 0, 0x00000006, 0 },
+                { X86_FEATURE_EPB,              CR_ECX, 3, 0x00000006, 0 },
+                { X86_FEATURE_XSAVEOPT,         CR_EAX, 0, 0x0000000d, 1 },
+                { X86_FEATURE_CPB,              CR_EDX, 9, 0x80000007, 0 },
+                { X86_FEATURE_NPT,              CR_EDX, 0, 0x8000000a, 0 },
+                { X86_FEATURE_LBRV,             CR_EDX, 1, 0x8000000a, 0 },
+                { X86_FEATURE_SVML,             CR_EDX, 2, 0x8000000a, 0 },
+                { X86_FEATURE_NRIPS,            CR_EDX, 3, 0x8000000a, 0 },
+                { 0, 0, 0, 0, 0 }
+        };
+
+        for (cb = cpuid_bits; cb->feature; cb++) {
+
+                /* Verify that the level is valid */
+                max_level = cpuid_eax(cb->level & 0xffff0000);
+                if (max_level < cb->level ||
+                    max_level > (cb->level | 0xffff))
+                        continue;
+
+                cpuid_count(cb->level, cb->sub_leaf, &regs[CR_EAX],
+                            &regs[CR_EBX], &regs[CR_ECX], &regs[CR_EDX]);
+
+                if (regs[cb->reg] & (1 << cb->bit))
+                        set_cpu_cap(c, cb->feature);
+        }
+}