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/*
* 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;
};
/* Please keep the leaf sorted by cpuid_bit.level for faster search. */
static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_APERFMPERF, CPUID_ECX, 0, 0x00000006, 0 },
{ X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 },
{ X86_FEATURE_INTEL_PT, CPUID_EBX, 25, 0x00000007, 0 },
{ X86_FEATURE_AVX512_4VNNIW, CPUID_EDX, 2, 0x00000007, 0 },
{ X86_FEATURE_AVX512_4FMAPS, CPUID_EDX, 3, 0x00000007, 0 },
{ X86_FEATURE_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 },
{ X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 },
{ X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 },
{ 0, 0, 0, 0, 0 }
};
void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
{
u32 max_level;
u32 regs[4];
const struct cpuid_bit *cb;
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, ®s[CPUID_EAX],
®s[CPUID_EBX], ®s[CPUID_ECX],
®s[CPUID_EDX]);
if (regs[cb->reg] & (1 << cb->bit))
set_cpu_cap(c, cb->feature);
}
}
u32 get_scattered_cpuid_leaf(unsigned int level, unsigned int sub_leaf,
enum cpuid_regs_idx reg)
{
const struct cpuid_bit *cb;
u32 cpuid_val = 0;
for (cb = cpuid_bits; cb->feature; cb++) {
if (level > cb->level)
continue;
if (level < cb->level)
break;
if (reg == cb->reg && sub_leaf == cb->sub_leaf) {
if (cpu_has(&boot_cpu_data, cb->feature))
cpuid_val |= BIT(cb->bit);
}
}
return cpuid_val;
}
EXPORT_SYMBOL_GPL(get_scattered_cpuid_leaf);
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