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 #ifdef CONFIG_SMP 29 /* 30 * Check if given CPUID extended topology "leaf" is implemented 31 */ 32 static int check_extended_topology_leaf(int leaf) 33 { 34 unsigned int eax, ebx, ecx, edx; 35 36 cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx); 37 38 if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE)) 39 return -1; 40 41 return 0; 42 } 43 /* 44 * Return best CPUID Extended Topology Leaf supported 45 */ 46 static int detect_extended_topology_leaf(struct cpuinfo_x86 *c) 47 { 48 if (c->cpuid_level >= 0x1f) { 49 if (check_extended_topology_leaf(0x1f) == 0) 50 return 0x1f; 51 } 52 53 if (c->cpuid_level >= 0xb) { 54 if (check_extended_topology_leaf(0xb) == 0) 55 return 0xb; 56 } 57 58 return -1; 59 } 60 #endif 61 62 int detect_extended_topology_early(struct cpuinfo_x86 *c) 63 { 64 #ifdef CONFIG_SMP 65 unsigned int eax, ebx, ecx, edx; 66 int leaf; 67 68 leaf = detect_extended_topology_leaf(c); 69 if (leaf < 0) 70 return -1; 71 72 set_cpu_cap(c, X86_FEATURE_XTOPOLOGY); 73 74 cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx); 75 /* 76 * initial apic id, which also represents 32-bit extended x2apic id. 77 */ 78 c->topo.initial_apicid = edx; 79 smp_num_siblings = max_t(int, smp_num_siblings, LEVEL_MAX_SIBLINGS(ebx)); 80 #endif 81 return 0; 82 } 83 84 /* 85 * Check for extended topology enumeration cpuid leaf, and if it 86 * exists, use it for populating initial_apicid and cpu topology 87 * detection. 88 */ 89 int detect_extended_topology(struct cpuinfo_x86 *c) 90 { 91 #ifdef CONFIG_SMP 92 unsigned int eax, ebx, ecx, edx, sub_index; 93 unsigned int ht_mask_width, core_plus_mask_width, die_plus_mask_width; 94 unsigned int core_select_mask, core_level_siblings; 95 unsigned int die_select_mask, die_level_siblings; 96 unsigned int pkg_mask_width; 97 bool die_level_present = false; 98 int leaf; 99 100 leaf = detect_extended_topology_leaf(c); 101 if (leaf < 0) 102 return -1; 103 104 /* 105 * Populate HT related information from sub-leaf level 0. 106 */ 107 cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx); 108 c->topo.initial_apicid = edx; 109 core_level_siblings = LEVEL_MAX_SIBLINGS(ebx); 110 smp_num_siblings = max_t(int, smp_num_siblings, LEVEL_MAX_SIBLINGS(ebx)); 111 core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 112 die_level_siblings = LEVEL_MAX_SIBLINGS(ebx); 113 pkg_mask_width = die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 114 115 sub_index = 1; 116 while (true) { 117 cpuid_count(leaf, sub_index, &eax, &ebx, &ecx, &edx); 118 119 /* 120 * Check for the Core type in the implemented sub leaves. 121 */ 122 if (LEAFB_SUBTYPE(ecx) == CORE_TYPE) { 123 core_level_siblings = LEVEL_MAX_SIBLINGS(ebx); 124 core_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 125 die_level_siblings = core_level_siblings; 126 die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 127 } 128 if (LEAFB_SUBTYPE(ecx) == DIE_TYPE) { 129 die_level_present = true; 130 die_level_siblings = LEVEL_MAX_SIBLINGS(ebx); 131 die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 132 } 133 134 if (LEAFB_SUBTYPE(ecx) != INVALID_TYPE) 135 pkg_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 136 else 137 break; 138 139 sub_index++; 140 } 141 142 core_select_mask = (~(-1 << pkg_mask_width)) >> ht_mask_width; 143 die_select_mask = (~(-1 << die_plus_mask_width)) >> 144 core_plus_mask_width; 145 146 c->topo.core_id = apic->phys_pkg_id(c->topo.initial_apicid, 147 ht_mask_width) & core_select_mask; 148 149 if (die_level_present) { 150 c->topo.die_id = apic->phys_pkg_id(c->topo.initial_apicid, 151 core_plus_mask_width) & die_select_mask; 152 } 153 154 c->topo.pkg_id = apic->phys_pkg_id(c->topo.initial_apicid, pkg_mask_width); 155 /* 156 * Reinit the apicid, now that we have extended initial_apicid. 157 */ 158 c->topo.apicid = apic->phys_pkg_id(c->topo.initial_apicid, 0); 159 160 c->x86_max_cores = (core_level_siblings / smp_num_siblings); 161 __max_die_per_package = (die_level_siblings / core_level_siblings); 162 #endif 163 return 0; 164 } 165