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 unsigned int __max_die_per_package __read_mostly = 1; 30 EXPORT_SYMBOL(__max_die_per_package); 31 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 int leaf; 100 101 leaf = detect_extended_topology_leaf(c); 102 if (leaf < 0) 103 return -1; 104 105 /* 106 * Populate HT related information from sub-leaf level 0. 107 */ 108 cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx); 109 c->initial_apicid = edx; 110 core_level_siblings = 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 die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 114 115 sub_index = 1; 116 do { 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_siblings = LEVEL_MAX_SIBLINGS(ebx); 130 die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); 131 } 132 133 sub_index++; 134 } while (LEAFB_SUBTYPE(ecx) != INVALID_TYPE); 135 136 core_select_mask = (~(-1 << core_plus_mask_width)) >> ht_mask_width; 137 die_select_mask = (~(-1 << die_plus_mask_width)) >> 138 core_plus_mask_width; 139 140 c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, 141 ht_mask_width) & core_select_mask; 142 c->cpu_die_id = apic->phys_pkg_id(c->initial_apicid, 143 core_plus_mask_width) & die_select_mask; 144 c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, 145 die_plus_mask_width); 146 /* 147 * Reinit the apicid, now that we have extended initial_apicid. 148 */ 149 c->apicid = apic->phys_pkg_id(c->initial_apicid, 0); 150 151 c->x86_max_cores = (core_level_siblings / smp_num_siblings); 152 __max_die_per_package = (die_level_siblings / core_level_siblings); 153 #endif 154 return 0; 155 } 156