1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Check for extended topology enumeration cpuid leaf 0xb and if it 4 * exists, use it for populating initial_apicid and cpu topology 5 * detection. 6 */ 7 8 #include <linux/cpu.h> 9 #include <asm/apic.h> 10 #include <asm/memtype.h> 11 #include <asm/processor.h> 12 13 #include "cpu.h" 14 15 /* leaf 0xb SMT level */ 16 #define SMT_LEVEL 0 17 18 /* extended topology sub-leaf types */ 19 #define INVALID_TYPE 0 20 #define SMT_TYPE 1 21 #define CORE_TYPE 2 22 #define DIE_TYPE 5 23 24 #define LEAFB_SUBTYPE(ecx) (((ecx) >> 8) & 0xff) 25 #define BITS_SHIFT_NEXT_LEVEL(eax) ((eax) & 0x1f) 26 #define LEVEL_MAX_SIBLINGS(ebx) ((ebx) & 0xffff) 27 28 unsigned int __max_die_per_package __read_mostly = 1; 29 EXPORT_SYMBOL(__max_die_per_package); 30 31 #ifdef CONFIG_SMP 32 /* 33 * Check if given CPUID extended toplogy "leaf" is implemented 34 */ 35 static int check_extended_topology_leaf(int leaf) 36 { 37 unsigned int eax, ebx, ecx, edx; 38 39 cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx); 40 41 if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE)) 42 return -1; 43 44 return 0; 45 } 46 /* 47 * Return best CPUID Extended Toplogy Leaf supported 48 */ 49 static int detect_extended_topology_leaf(struct cpuinfo_x86 *c) 50 { 51 if (c->cpuid_level >= 0x1f) { 52 if (check_extended_topology_leaf(0x1f) == 0) 53 return 0x1f; 54 } 55 56 if (c->cpuid_level >= 0xb) { 57 if (check_extended_topology_leaf(0xb) == 0) 58 return 0xb; 59 } 60 61 return -1; 62 } 63 #endif 64 65 int detect_extended_topology_early(struct cpuinfo_x86 *c) 66 { 67 #ifdef CONFIG_SMP 68 unsigned int eax, ebx, ecx, edx; 69 int leaf; 70 71 leaf = detect_extended_topology_leaf(c); 72 if (leaf < 0) 73 return -1; 74 75 set_cpu_cap(c, X86_FEATURE_XTOPOLOGY); 76 77 cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx); 78 /* 79 * initial apic id, which also represents 32-bit extended x2apic id. 80 */ 81 c->initial_apicid = edx; 82 smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx); 83 #endif 84 return 0; 85 } 86 87 /* 88 * Check for extended topology enumeration cpuid leaf, and if it 89 * exists, use it for populating initial_apicid and cpu topology 90 * detection. 91 */ 92 int detect_extended_topology(struct cpuinfo_x86 *c) 93 { 94 #ifdef CONFIG_SMP 95 unsigned int eax, ebx, ecx, edx, sub_index; 96 unsigned int ht_mask_width, core_plus_mask_width, die_plus_mask_width; 97 unsigned int core_select_mask, core_level_siblings; 98 unsigned int die_select_mask, die_level_siblings; 99 bool die_level_present = false; 100 int leaf; 101 102 leaf = detect_extended_topology_leaf(c); 103 if (leaf < 0) 104 return -1; 105 106 /* 107 * Populate HT related information from sub-leaf level 0. 108 */ 109 cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx); 110 c->initial_apicid = edx; 111 core_level_siblings = smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx); 112 core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 113 die_level_siblings = LEVEL_MAX_SIBLINGS(ebx); 114 die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 115 116 sub_index = 1; 117 do { 118 cpuid_count(leaf, sub_index, &eax, &ebx, &ecx, &edx); 119 120 /* 121 * Check for the Core type in the implemented sub leaves. 122 */ 123 if (LEAFB_SUBTYPE(ecx) == CORE_TYPE) { 124 core_level_siblings = LEVEL_MAX_SIBLINGS(ebx); 125 core_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 126 die_level_siblings = core_level_siblings; 127 die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 128 } 129 if (LEAFB_SUBTYPE(ecx) == DIE_TYPE) { 130 die_level_present = true; 131 die_level_siblings = LEVEL_MAX_SIBLINGS(ebx); 132 die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 133 } 134 135 sub_index++; 136 } while (LEAFB_SUBTYPE(ecx) != INVALID_TYPE); 137 138 core_select_mask = (~(-1 << core_plus_mask_width)) >> ht_mask_width; 139 die_select_mask = (~(-1 << die_plus_mask_width)) >> 140 core_plus_mask_width; 141 142 c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, 143 ht_mask_width) & core_select_mask; 144 145 if (die_level_present) { 146 c->cpu_die_id = apic->phys_pkg_id(c->initial_apicid, 147 core_plus_mask_width) & die_select_mask; 148 } 149 150 c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, 151 die_plus_mask_width); 152 /* 153 * Reinit the apicid, now that we have extended initial_apicid. 154 */ 155 c->apicid = apic->phys_pkg_id(c->initial_apicid, 0); 156 157 c->x86_max_cores = (core_level_siblings / smp_num_siblings); 158 __max_die_per_package = (die_level_siblings / core_level_siblings); 159 #endif 160 return 0; 161 } 162