xref: /qemu/include/hw/i386/topology.h (revision 513823e7521a09ed7ad1e32e6454bac3b2cbf52d)
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 /*
28  * This file implements the APIC-ID-based CPU topology enumeration logic,
29  * documented at the following document:
30  *   Intel® 64 Architecture Processor Topology Enumeration
31  *   http://software.intel.com/en-us/articles/intel-64-architecture-processor-topology-enumeration/
32  *
33  * This code should be compatible with AMD's "Extended Method" described at:
34  *   AMD CPUID Specification (Publication #25481)
35  *   Section 3: Multiple Core Calculation
36  * as long as:
37  *  nr_threads is set to 1;
38  *  OFFSET_IDX is assumed to be 0;
39  *  CPUID Fn8000_0008_ECX[ApicIdCoreIdSize[3:0]] is set to apicid_core_width().
40  */
41 
42 #include "qapi/qapi-types-machine-common.h"
43 #include "qemu/bitops.h"
44 
45 /*
46  * APIC IDs can be 32-bit, but beware: APIC IDs > 255 require x2APIC support
47  */
48 typedef uint32_t apic_id_t;
49 
50 typedef struct X86CPUTopoIDs {
51     unsigned pkg_id;
52     unsigned die_id;
53     unsigned module_id;
54     unsigned core_id;
55     unsigned smt_id;
56 } X86CPUTopoIDs;
57 
58 typedef struct X86CPUTopoInfo {
59     unsigned dies_per_pkg;
60     unsigned modules_per_die;
61     unsigned cores_per_module;
62     unsigned threads_per_core;
63 } X86CPUTopoInfo;
64 
65 #define CPU_TOPOLOGY_LEVEL_INVALID CPU_TOPOLOGY_LEVEL__MAX
66 
67 /* Return the bit width needed for 'count' IDs */
68 static unsigned apicid_bitwidth_for_count(unsigned count)
69 {
70     g_assert(count >= 1);
71     count -= 1;
72     return count ? 32 - clz32(count) : 0;
73 }
74 
75 /* Bit width of the SMT_ID (thread ID) field on the APIC ID */
76 static inline unsigned apicid_smt_width(X86CPUTopoInfo *topo_info)
77 {
78     return apicid_bitwidth_for_count(topo_info->threads_per_core);
79 }
80 
81 /* Bit width of the Core_ID field */
82 static inline unsigned apicid_core_width(X86CPUTopoInfo *topo_info)
83 {
84     return apicid_bitwidth_for_count(topo_info->cores_per_module);
85 }
86 
87 /* Bit width of the Module_ID field */
88 static inline unsigned apicid_module_width(X86CPUTopoInfo *topo_info)
89 {
90     return apicid_bitwidth_for_count(topo_info->modules_per_die);
91 }
92 
93 /* Bit width of the Die_ID field */
94 static inline unsigned apicid_die_width(X86CPUTopoInfo *topo_info)
95 {
96     return apicid_bitwidth_for_count(topo_info->dies_per_pkg);
97 }
98 
99 /* Bit offset of the Core_ID field */
100 static inline unsigned apicid_core_offset(X86CPUTopoInfo *topo_info)
101 {
102     return apicid_smt_width(topo_info);
103 }
104 
105 /* Bit offset of the Module_ID field */
106 static inline unsigned apicid_module_offset(X86CPUTopoInfo *topo_info)
107 {
108     return apicid_core_offset(topo_info) + apicid_core_width(topo_info);
109 }
110 
111 /* Bit offset of the Die_ID field */
112 static inline unsigned apicid_die_offset(X86CPUTopoInfo *topo_info)
113 {
114     return apicid_module_offset(topo_info) + apicid_module_width(topo_info);
115 }
116 
117 /* Bit offset of the Pkg_ID (socket ID) field */
118 static inline unsigned apicid_pkg_offset(X86CPUTopoInfo *topo_info)
119 {
120     return apicid_die_offset(topo_info) + apicid_die_width(topo_info);
121 }
122 
123 /*
124  * Make APIC ID for the CPU based on topology and IDs of each topology level.
125  *
126  * The caller must make sure the ID of each level doesn't exceed the width of
127  * the level.
128  */
129 static inline apic_id_t x86_apicid_from_topo_ids(X86CPUTopoInfo *topo_info,
130                                                  const X86CPUTopoIDs *topo_ids)
131 {
132     return (topo_ids->pkg_id  << apicid_pkg_offset(topo_info)) |
133            (topo_ids->die_id  << apicid_die_offset(topo_info)) |
134            (topo_ids->module_id << apicid_module_offset(topo_info)) |
135            (topo_ids->core_id << apicid_core_offset(topo_info)) |
136            topo_ids->smt_id;
137 }
138 
139 /*
140  * Calculate thread/core/package IDs for a specific topology,
141  * based on (contiguous) CPU index
142  */
143 static inline void x86_topo_ids_from_idx(X86CPUTopoInfo *topo_info,
144                                          unsigned cpu_index,
145                                          X86CPUTopoIDs *topo_ids)
146 {
147     unsigned nr_dies = topo_info->dies_per_pkg;
148     unsigned nr_modules = topo_info->modules_per_die;
149     unsigned nr_cores = topo_info->cores_per_module;
150     unsigned nr_threads = topo_info->threads_per_core;
151 
152     topo_ids->pkg_id = cpu_index / (nr_dies * nr_modules *
153                        nr_cores * nr_threads);
154     topo_ids->die_id = cpu_index / (nr_modules * nr_cores *
155                        nr_threads) % nr_dies;
156     topo_ids->module_id = cpu_index / (nr_cores * nr_threads) %
157                           nr_modules;
158     topo_ids->core_id = cpu_index / nr_threads % nr_cores;
159     topo_ids->smt_id = cpu_index % nr_threads;
160 }
161 
162 /*
163  * Calculate thread/core/package IDs for a specific topology,
164  * based on APIC ID
165  */
166 static inline void x86_topo_ids_from_apicid(apic_id_t apicid,
167                                             X86CPUTopoInfo *topo_info,
168                                             X86CPUTopoIDs *topo_ids)
169 {
170     topo_ids->smt_id = apicid &
171             ~(0xFFFFFFFFUL << apicid_smt_width(topo_info));
172     topo_ids->core_id =
173             (apicid >> apicid_core_offset(topo_info)) &
174             ~(0xFFFFFFFFUL << apicid_core_width(topo_info));
175     topo_ids->module_id =
176             (apicid >> apicid_module_offset(topo_info)) &
177             ~(0xFFFFFFFFUL << apicid_module_width(topo_info));
178     topo_ids->die_id =
179             (apicid >> apicid_die_offset(topo_info)) &
180             ~(0xFFFFFFFFUL << apicid_die_width(topo_info));
181     topo_ids->pkg_id = apicid >> apicid_pkg_offset(topo_info);
182 }
183 
184 /*
185  * Make APIC ID for the CPU 'cpu_index'
186  *
187  * 'cpu_index' is a sequential, contiguous ID for the CPU.
188  */
189 static inline apic_id_t x86_apicid_from_cpu_idx(X86CPUTopoInfo *topo_info,
190                                                 unsigned cpu_index)
191 {
192     X86CPUTopoIDs topo_ids;
193     x86_topo_ids_from_idx(topo_info, cpu_index, &topo_ids);
194     return x86_apicid_from_topo_ids(topo_info, &topo_ids);
195 }
196 
197 /*
198  * Check whether there's extended topology level (module or die)?
199  */
200 static inline bool x86_has_extended_topo(unsigned long *topo_bitmap)
201 {
202     return test_bit(CPU_TOPOLOGY_LEVEL_MODULE, topo_bitmap) ||
203            test_bit(CPU_TOPOLOGY_LEVEL_DIE, topo_bitmap);
204 }
205 
206 static inline unsigned x86_module_per_pkg(X86CPUTopoInfo *topo_info)
207 {
208     return topo_info->modules_per_die * topo_info->dies_per_pkg;
209 }
210 
211 static inline unsigned x86_cores_per_pkg(X86CPUTopoInfo *topo_info)
212 {
213     return topo_info->cores_per_module * x86_module_per_pkg(topo_info);
214 }
215 
216 static inline unsigned x86_threads_per_pkg(X86CPUTopoInfo *topo_info)
217 {
218     return topo_info->threads_per_core * x86_cores_per_pkg(topo_info);
219 }
220 
221 static inline unsigned x86_threads_per_module(X86CPUTopoInfo *topo_info)
222 {
223     return topo_info->threads_per_core * topo_info->cores_per_module;
224 }
225 
226 static inline unsigned x86_threads_per_die(X86CPUTopoInfo *topo_info)
227 {
228     return x86_threads_per_module(topo_info) * topo_info->modules_per_die;
229 }
230 
231 #endif /* HW_I386_TOPOLOGY_H */
232