/* * Routines to indentify additional cpu features that are scattered in * cpuid space. */ #include #include struct cpuid_bit { u16 feature; u8 reg; u8 bit; u32 level; }; 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 cpuid_bits[] = { { X86_FEATURE_IDA, CR_EAX, 1, 0x00000006 }, { 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(cb->level, ®s[CR_EAX], ®s[CR_EBX], ®s[CR_ECX], ®s[CR_EDX]); if (regs[cb->reg] & (1 << cb->bit)) set_bit(cb->feature, c->x86_capability); } }