1 /* 2 * x86 CPU topology data structures and functions 3 * 4 * Copyright (c) 2012 Red Hat Inc. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 #ifndef HW_I386_TOPOLOGY_H 25 #define HW_I386_TOPOLOGY_H 26 27 /* This file implements the APIC-ID-based CPU topology enumeration logic, 28 * documented at the following document: 29 * Intel® 64 Architecture Processor Topology Enumeration 30 * http://software.intel.com/en-us/articles/intel-64-architecture-processor-topology-enumeration/ 31 * 32 * This code should be compatible with AMD's "Extended Method" described at: 33 * AMD CPUID Specification (Publication #25481) 34 * Section 3: Multiple Core Calcuation 35 * as long as: 36 * nr_threads is set to 1; 37 * OFFSET_IDX is assumed to be 0; 38 * CPUID Fn8000_0008_ECX[ApicIdCoreIdSize[3:0]] is set to apicid_core_width(). 39 */ 40 41 42 #include "qemu/bitops.h" 43 44 /* APIC IDs can be 32-bit, but beware: APIC IDs > 255 require x2APIC support 45 */ 46 typedef uint32_t apic_id_t; 47 48 typedef struct X86CPUTopoIDs { 49 unsigned pkg_id; 50 unsigned die_id; 51 unsigned core_id; 52 unsigned smt_id; 53 } X86CPUTopoIDs; 54 55 /* Return the bit width needed for 'count' IDs 56 */ 57 static unsigned apicid_bitwidth_for_count(unsigned count) 58 { 59 g_assert(count >= 1); 60 count -= 1; 61 return count ? 32 - clz32(count) : 0; 62 } 63 64 /* Bit width of the SMT_ID (thread ID) field on the APIC ID 65 */ 66 static inline unsigned apicid_smt_width(unsigned nr_dies, 67 unsigned nr_cores, 68 unsigned nr_threads) 69 { 70 return apicid_bitwidth_for_count(nr_threads); 71 } 72 73 /* Bit width of the Core_ID field 74 */ 75 static inline unsigned apicid_core_width(unsigned nr_dies, 76 unsigned nr_cores, 77 unsigned nr_threads) 78 { 79 return apicid_bitwidth_for_count(nr_cores); 80 } 81 82 /* Bit width of the Die_ID field */ 83 static inline unsigned apicid_die_width(unsigned nr_dies, 84 unsigned nr_cores, 85 unsigned nr_threads) 86 { 87 return apicid_bitwidth_for_count(nr_dies); 88 } 89 90 /* Bit offset of the Core_ID field 91 */ 92 static inline unsigned apicid_core_offset(unsigned nr_dies, 93 unsigned nr_cores, 94 unsigned nr_threads) 95 { 96 return apicid_smt_width(nr_dies, nr_cores, nr_threads); 97 } 98 99 /* Bit offset of the Die_ID field */ 100 static inline unsigned apicid_die_offset(unsigned nr_dies, 101 unsigned nr_cores, 102 unsigned nr_threads) 103 { 104 return apicid_core_offset(nr_dies, nr_cores, nr_threads) + 105 apicid_core_width(nr_dies, nr_cores, nr_threads); 106 } 107 108 /* Bit offset of the Pkg_ID (socket ID) field 109 */ 110 static inline unsigned apicid_pkg_offset(unsigned nr_dies, 111 unsigned nr_cores, 112 unsigned nr_threads) 113 { 114 return apicid_die_offset(nr_dies, nr_cores, nr_threads) + 115 apicid_die_width(nr_dies, nr_cores, nr_threads); 116 } 117 118 /* Make APIC ID for the CPU based on Pkg_ID, Core_ID, SMT_ID 119 * 120 * The caller must make sure core_id < nr_cores and smt_id < nr_threads. 121 */ 122 static inline apic_id_t apicid_from_topo_ids(unsigned nr_dies, 123 unsigned nr_cores, 124 unsigned nr_threads, 125 const X86CPUTopoIDs *topo_ids) 126 { 127 return (topo_ids->pkg_id << 128 apicid_pkg_offset(nr_dies, nr_cores, nr_threads)) | 129 (topo_ids->die_id << 130 apicid_die_offset(nr_dies, nr_cores, nr_threads)) | 131 (topo_ids->core_id << 132 apicid_core_offset(nr_dies, nr_cores, nr_threads)) | 133 topo_ids->smt_id; 134 } 135 136 /* Calculate thread/core/package IDs for a specific topology, 137 * based on (contiguous) CPU index 138 */ 139 static inline void x86_topo_ids_from_idx(unsigned nr_dies, 140 unsigned nr_cores, 141 unsigned nr_threads, 142 unsigned cpu_index, 143 X86CPUTopoIDs *topo_ids) 144 { 145 topo_ids->pkg_id = cpu_index / (nr_dies * nr_cores * nr_threads); 146 topo_ids->die_id = cpu_index / (nr_cores * nr_threads) % nr_dies; 147 topo_ids->core_id = cpu_index / nr_threads % nr_cores; 148 topo_ids->smt_id = cpu_index % nr_threads; 149 } 150 151 /* Calculate thread/core/package IDs for a specific topology, 152 * based on APIC ID 153 */ 154 static inline void x86_topo_ids_from_apicid(apic_id_t apicid, 155 unsigned nr_dies, 156 unsigned nr_cores, 157 unsigned nr_threads, 158 X86CPUTopoIDs *topo_ids) 159 { 160 topo_ids->smt_id = apicid & 161 ~(0xFFFFFFFFUL << apicid_smt_width(nr_dies, nr_cores, nr_threads)); 162 topo_ids->core_id = 163 (apicid >> apicid_core_offset(nr_dies, nr_cores, nr_threads)) & 164 ~(0xFFFFFFFFUL << apicid_core_width(nr_dies, nr_cores, nr_threads)); 165 topo_ids->die_id = 166 (apicid >> apicid_die_offset(nr_dies, nr_cores, nr_threads)) & 167 ~(0xFFFFFFFFUL << apicid_die_width(nr_dies, nr_cores, nr_threads)); 168 topo_ids->pkg_id = 169 apicid >> apicid_pkg_offset(nr_dies, nr_cores, nr_threads); 170 } 171 172 /* Make APIC ID for the CPU 'cpu_index' 173 * 174 * 'cpu_index' is a sequential, contiguous ID for the CPU. 175 */ 176 static inline apic_id_t x86_apicid_from_cpu_idx(unsigned nr_dies, 177 unsigned nr_cores, 178 unsigned nr_threads, 179 unsigned cpu_index) 180 { 181 X86CPUTopoIDs topo_ids; 182 x86_topo_ids_from_idx(nr_dies, nr_cores, nr_threads, cpu_index, &topo_ids); 183 return apicid_from_topo_ids(nr_dies, nr_cores, nr_threads, &topo_ids); 184 } 185 186 #endif /* HW_I386_TOPOLOGY_H */ 187