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 topology "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 Topology 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->topo.initial_apicid = edx; 82 smp_num_siblings = max_t(int, 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 unsigned int pkg_mask_width; 100 bool die_level_present = false; 101 int leaf; 102 103 leaf = detect_extended_topology_leaf(c); 104 if (leaf < 0) 105 return -1; 106 107 /* 108 * Populate HT related information from sub-leaf level 0. 109 */ 110 cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx); 111 c->topo.initial_apicid = edx; 112 core_level_siblings = LEVEL_MAX_SIBLINGS(ebx); 113 smp_num_siblings = max_t(int, smp_num_siblings, LEVEL_MAX_SIBLINGS(ebx)); 114 core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 115 die_level_siblings = LEVEL_MAX_SIBLINGS(ebx); 116 pkg_mask_width = die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 117 118 sub_index = 1; 119 while (true) { 120 cpuid_count(leaf, sub_index, &eax, &ebx, &ecx, &edx); 121 122 /* 123 * Check for the Core type in the implemented sub leaves. 124 */ 125 if (LEAFB_SUBTYPE(ecx) == CORE_TYPE) { 126 core_level_siblings = LEVEL_MAX_SIBLINGS(ebx); 127 core_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 128 die_level_siblings = core_level_siblings; 129 die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 130 } 131 if (LEAFB_SUBTYPE(ecx) == DIE_TYPE) { 132 die_level_present = true; 133 die_level_siblings = LEVEL_MAX_SIBLINGS(ebx); 134 die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 135 } 136 137 if (LEAFB_SUBTYPE(ecx) != INVALID_TYPE) 138 pkg_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 139 else 140 break; 141 142 sub_index++; 143 } 144 145 core_select_mask = (~(-1 << pkg_mask_width)) >> ht_mask_width; 146 die_select_mask = (~(-1 << die_plus_mask_width)) >> 147 core_plus_mask_width; 148 149 c->topo.core_id = apic->phys_pkg_id(c->topo.initial_apicid, 150 ht_mask_width) & core_select_mask; 151 152 if (die_level_present) { 153 c->topo.die_id = apic->phys_pkg_id(c->topo.initial_apicid, 154 core_plus_mask_width) & die_select_mask; 155 } 156 157 c->topo.pkg_id = apic->phys_pkg_id(c->topo.initial_apicid, pkg_mask_width); 158 /* 159 * Reinit the apicid, now that we have extended initial_apicid. 160 */ 161 c->topo.apicid = apic->phys_pkg_id(c->topo.initial_apicid, 0); 162 163 c->x86_max_cores = (core_level_siblings / smp_num_siblings); 164 __max_die_per_package = (die_level_siblings / core_level_siblings); 165 #endif 166 return 0; 167 } 168