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/apic.h> 9 #include <asm/processor.h> 10 11 #include "cpu.h" 12 13 struct cpuid_bit { 14 u16 feature; 15 u8 reg; 16 u8 bit; 17 u32 level; 18 u32 sub_leaf; 19 }; 20 21 /* Please keep the leaf sorted by cpuid_bit.level for faster search. */ 22 static const struct cpuid_bit cpuid_bits[] = { 23 { X86_FEATURE_APERFMPERF, CPUID_ECX, 0, 0x00000006, 0 }, 24 { X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 }, 25 { X86_FEATURE_CAT_L3, CPUID_EBX, 1, 0x00000010, 0 }, 26 { X86_FEATURE_CAT_L2, CPUID_EBX, 2, 0x00000010, 0 }, 27 { X86_FEATURE_CDP_L3, CPUID_ECX, 2, 0x00000010, 1 }, 28 { X86_FEATURE_CDP_L2, CPUID_ECX, 2, 0x00000010, 2 }, 29 { X86_FEATURE_MBA, CPUID_EBX, 3, 0x00000010, 0 }, 30 { X86_FEATURE_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 }, 31 { X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 }, 32 { X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 }, 33 { X86_FEATURE_SME, CPUID_EAX, 0, 0x8000001f, 0 }, 34 { X86_FEATURE_SEV, CPUID_EAX, 1, 0x8000001f, 0 }, 35 { 0, 0, 0, 0, 0 } 36 }; 37 38 void init_scattered_cpuid_features(struct cpuinfo_x86 *c) 39 { 40 u32 max_level; 41 u32 regs[4]; 42 const struct cpuid_bit *cb; 43 44 for (cb = cpuid_bits; cb->feature; cb++) { 45 46 /* Verify that the level is valid */ 47 max_level = cpuid_eax(cb->level & 0xffff0000); 48 if (max_level < cb->level || 49 max_level > (cb->level | 0xffff)) 50 continue; 51 52 cpuid_count(cb->level, cb->sub_leaf, ®s[CPUID_EAX], 53 ®s[CPUID_EBX], ®s[CPUID_ECX], 54 ®s[CPUID_EDX]); 55 56 if (regs[cb->reg] & (1 << cb->bit)) 57 set_cpu_cap(c, cb->feature); 58 } 59 } 60 61 u32 get_scattered_cpuid_leaf(unsigned int level, unsigned int sub_leaf, 62 enum cpuid_regs_idx reg) 63 { 64 const struct cpuid_bit *cb; 65 u32 cpuid_val = 0; 66 67 for (cb = cpuid_bits; cb->feature; cb++) { 68 69 if (level > cb->level) 70 continue; 71 72 if (level < cb->level) 73 break; 74 75 if (reg == cb->reg && sub_leaf == cb->sub_leaf) { 76 if (cpu_has(&boot_cpu_data, cb->feature)) 77 cpuid_val |= BIT(cb->bit); 78 } 79 } 80 81 return cpuid_val; 82 } 83 EXPORT_SYMBOL_GPL(get_scattered_cpuid_leaf); 84