xref: /openbmc/qemu/include/hw/i386/topology.h (revision 4f7b1ecb)
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 
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 /*
66  * CPUTopoLevel is the general i386 topology hierarchical representation,
67  * ordered by increasing hierarchical relationship.
68  * Its enumeration value is not bound to the type value of Intel (CPUID[0x1F])
69  * or AMD (CPUID[0x80000026]).
70  */
71 enum CPUTopoLevel {
72     CPU_TOPO_LEVEL_INVALID,
73     CPU_TOPO_LEVEL_SMT,
74     CPU_TOPO_LEVEL_CORE,
75     CPU_TOPO_LEVEL_MODULE,
76     CPU_TOPO_LEVEL_DIE,
77     CPU_TOPO_LEVEL_PACKAGE,
78     CPU_TOPO_LEVEL_MAX,
79 };
80 
81 /* Return the bit width needed for 'count' IDs */
82 static unsigned apicid_bitwidth_for_count(unsigned count)
83 {
84     g_assert(count >= 1);
85     count -= 1;
86     return count ? 32 - clz32(count) : 0;
87 }
88 
89 /* Bit width of the SMT_ID (thread ID) field on the APIC ID */
90 static inline unsigned apicid_smt_width(X86CPUTopoInfo *topo_info)
91 {
92     return apicid_bitwidth_for_count(topo_info->threads_per_core);
93 }
94 
95 /* Bit width of the Core_ID field */
96 static inline unsigned apicid_core_width(X86CPUTopoInfo *topo_info)
97 {
98     return apicid_bitwidth_for_count(topo_info->cores_per_module);
99 }
100 
101 /* Bit width of the Module_ID field */
102 static inline unsigned apicid_module_width(X86CPUTopoInfo *topo_info)
103 {
104     return apicid_bitwidth_for_count(topo_info->modules_per_die);
105 }
106 
107 /* Bit width of the Die_ID field */
108 static inline unsigned apicid_die_width(X86CPUTopoInfo *topo_info)
109 {
110     return apicid_bitwidth_for_count(topo_info->dies_per_pkg);
111 }
112 
113 /* Bit offset of the Core_ID field */
114 static inline unsigned apicid_core_offset(X86CPUTopoInfo *topo_info)
115 {
116     return apicid_smt_width(topo_info);
117 }
118 
119 /* Bit offset of the Module_ID field */
120 static inline unsigned apicid_module_offset(X86CPUTopoInfo *topo_info)
121 {
122     return apicid_core_offset(topo_info) + apicid_core_width(topo_info);
123 }
124 
125 /* Bit offset of the Die_ID field */
126 static inline unsigned apicid_die_offset(X86CPUTopoInfo *topo_info)
127 {
128     return apicid_module_offset(topo_info) + apicid_module_width(topo_info);
129 }
130 
131 /* Bit offset of the Pkg_ID (socket ID) field */
132 static inline unsigned apicid_pkg_offset(X86CPUTopoInfo *topo_info)
133 {
134     return apicid_die_offset(topo_info) + apicid_die_width(topo_info);
135 }
136 
137 /*
138  * Make APIC ID for the CPU based on Pkg_ID, Core_ID, SMT_ID
139  *
140  * The caller must make sure core_id < nr_cores and smt_id < nr_threads.
141  */
142 static inline apic_id_t x86_apicid_from_topo_ids(X86CPUTopoInfo *topo_info,
143                                                  const X86CPUTopoIDs *topo_ids)
144 {
145     return (topo_ids->pkg_id  << apicid_pkg_offset(topo_info)) |
146            (topo_ids->die_id  << apicid_die_offset(topo_info)) |
147            (topo_ids->module_id << apicid_module_offset(topo_info)) |
148            (topo_ids->core_id << apicid_core_offset(topo_info)) |
149            topo_ids->smt_id;
150 }
151 
152 /*
153  * Calculate thread/core/package IDs for a specific topology,
154  * based on (contiguous) CPU index
155  */
156 static inline void x86_topo_ids_from_idx(X86CPUTopoInfo *topo_info,
157                                          unsigned cpu_index,
158                                          X86CPUTopoIDs *topo_ids)
159 {
160     unsigned nr_dies = topo_info->dies_per_pkg;
161     unsigned nr_modules = topo_info->modules_per_die;
162     unsigned nr_cores = topo_info->cores_per_module;
163     unsigned nr_threads = topo_info->threads_per_core;
164 
165     topo_ids->pkg_id = cpu_index / (nr_dies * nr_modules *
166                        nr_cores * nr_threads);
167     topo_ids->die_id = cpu_index / (nr_modules * nr_cores *
168                        nr_threads) % nr_dies;
169     topo_ids->module_id = cpu_index / (nr_cores * nr_threads) %
170                           nr_modules;
171     topo_ids->core_id = cpu_index / nr_threads % nr_cores;
172     topo_ids->smt_id = cpu_index % nr_threads;
173 }
174 
175 /*
176  * Calculate thread/core/package IDs for a specific topology,
177  * based on APIC ID
178  */
179 static inline void x86_topo_ids_from_apicid(apic_id_t apicid,
180                                             X86CPUTopoInfo *topo_info,
181                                             X86CPUTopoIDs *topo_ids)
182 {
183     topo_ids->smt_id = apicid &
184             ~(0xFFFFFFFFUL << apicid_smt_width(topo_info));
185     topo_ids->core_id =
186             (apicid >> apicid_core_offset(topo_info)) &
187             ~(0xFFFFFFFFUL << apicid_core_width(topo_info));
188     topo_ids->module_id =
189             (apicid >> apicid_module_offset(topo_info)) &
190             ~(0xFFFFFFFFUL << apicid_module_width(topo_info));
191     topo_ids->die_id =
192             (apicid >> apicid_die_offset(topo_info)) &
193             ~(0xFFFFFFFFUL << apicid_die_width(topo_info));
194     topo_ids->pkg_id = apicid >> apicid_pkg_offset(topo_info);
195 }
196 
197 /*
198  * Make APIC ID for the CPU 'cpu_index'
199  *
200  * 'cpu_index' is a sequential, contiguous ID for the CPU.
201  */
202 static inline apic_id_t x86_apicid_from_cpu_idx(X86CPUTopoInfo *topo_info,
203                                                 unsigned cpu_index)
204 {
205     X86CPUTopoIDs topo_ids;
206     x86_topo_ids_from_idx(topo_info, cpu_index, &topo_ids);
207     return x86_apicid_from_topo_ids(topo_info, &topo_ids);
208 }
209 
210 /*
211  * Check whether there's extended topology level (module or die)?
212  */
213 static inline bool x86_has_extended_topo(unsigned long *topo_bitmap)
214 {
215     return test_bit(CPU_TOPO_LEVEL_MODULE, topo_bitmap) ||
216            test_bit(CPU_TOPO_LEVEL_DIE, topo_bitmap);
217 }
218 
219 #endif /* HW_I386_TOPOLOGY_H */
220