blob: 8cb57df9398d91a74eec678134844d8ac1052463 [file] [log] [blame]
/*
* Routines to identify 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 init_scattered_cpuid_features(struct cpuinfo_x86 *c)
{
u32 max_level;
u32 regs[4];
const struct cpuid_bit *cb;
static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_INTEL_PT, CR_EBX,25, 0x00000007, 0 },
{ X86_FEATURE_APERFMPERF, CR_ECX, 0, 0x00000006, 0 },
{ X86_FEATURE_EPB, CR_ECX, 3, 0x00000006, 0 },
{ X86_FEATURE_HW_PSTATE, CR_EDX, 7, 0x80000007, 0 },
{ X86_FEATURE_CPB, CR_EDX, 9, 0x80000007, 0 },
{ X86_FEATURE_PROC_FEEDBACK, CR_EDX,11, 0x80000007, 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);
}
}