1 /* 2 * Routines to identify additional cpu features that are scattered in 3 * cpuid space. 4 */ 5 #include <linux/cpu.h> 6 7 #include <asm/pat.h> 8 #include <asm/processor.h> 9 10 #include <asm/apic.h> 11 12 struct cpuid_bit { 13 u16 feature; 14 u8 reg; 15 u8 bit; 16 u32 level; 17 u32 sub_leaf; 18 }; 19 20 enum cpuid_regs { 21 CR_EAX = 0, 22 CR_ECX, 23 CR_EDX, 24 CR_EBX 25 }; 26 27 void init_scattered_cpuid_features(struct cpuinfo_x86 *c) 28 { 29 u32 max_level; 30 u32 regs[4]; 31 const struct cpuid_bit *cb; 32 33 static const struct cpuid_bit cpuid_bits[] = { 34 { X86_FEATURE_INTEL_PT, CR_EBX,25, 0x00000007, 0 }, 35 { X86_FEATURE_AVX512_4VNNIW, CR_EDX, 2, 0x00000007, 0 }, 36 { X86_FEATURE_AVX512_4FMAPS, CR_EDX, 3, 0x00000007, 0 }, 37 { X86_FEATURE_APERFMPERF, CR_ECX, 0, 0x00000006, 0 }, 38 { X86_FEATURE_EPB, CR_ECX, 3, 0x00000006, 0 }, 39 { X86_FEATURE_HW_PSTATE, CR_EDX, 7, 0x80000007, 0 }, 40 { X86_FEATURE_CPB, CR_EDX, 9, 0x80000007, 0 }, 41 { X86_FEATURE_PROC_FEEDBACK, CR_EDX,11, 0x80000007, 0 }, 42 { 0, 0, 0, 0, 0 } 43 }; 44 45 for (cb = cpuid_bits; cb->feature; cb++) { 46 47 /* Verify that the level is valid */ 48 max_level = cpuid_eax(cb->level & 0xffff0000); 49 if (max_level < cb->level || 50 max_level > (cb->level | 0xffff)) 51 continue; 52 53 cpuid_count(cb->level, cb->sub_leaf, ®s[CR_EAX], 54 ®s[CR_EBX], ®s[CR_ECX], ®s[CR_EDX]); 55 56 if (regs[cb->reg] & (1 << cb->bit)) 57 set_cpu_cap(c, cb->feature); 58 } 59 } 60