2 * x86 CPU topology data structures and functions
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24 #ifndef HW_I386_TOPOLOGY_H
25 #define HW_I386_TOPOLOGY_H
28 * This file implements the APIC-ID-based CPU topology enumeration logic,
29 * documented at the following document:
30 * IntelĀ® 64 Architecture Processor Topology Enumeration
31 * http://software.intel.com/en-us/articles/intel-64-architecture-processor-topology-enumeration/
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
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().
43 #include "qemu/bitops.h"
46 * APIC IDs can be 32-bit, but beware: APIC IDs > 255 require x2APIC support
48 typedef uint32_t apic_id_t
;
50 typedef struct X86CPUTopoIDs
{
57 typedef struct X86CPUTopoInfo
{
58 unsigned dies_per_pkg
;
59 unsigned cores_per_die
;
60 unsigned threads_per_core
;
63 /* Return the bit width needed for 'count' IDs */
64 static unsigned apicid_bitwidth_for_count(unsigned count
)
68 return count
? 32 - clz32(count
) : 0;
71 /* Bit width of the SMT_ID (thread ID) field on the APIC ID */
72 static inline unsigned apicid_smt_width(X86CPUTopoInfo
*topo_info
)
74 return apicid_bitwidth_for_count(topo_info
->threads_per_core
);
77 /* Bit width of the Core_ID field */
78 static inline unsigned apicid_core_width(X86CPUTopoInfo
*topo_info
)
80 return apicid_bitwidth_for_count(topo_info
->cores_per_die
);
83 /* Bit width of the Die_ID field */
84 static inline unsigned apicid_die_width(X86CPUTopoInfo
*topo_info
)
86 return apicid_bitwidth_for_count(topo_info
->dies_per_pkg
);
89 /* Bit offset of the Core_ID field */
90 static inline unsigned apicid_core_offset(X86CPUTopoInfo
*topo_info
)
92 return apicid_smt_width(topo_info
);
95 /* Bit offset of the Die_ID field */
96 static inline unsigned apicid_die_offset(X86CPUTopoInfo
*topo_info
)
98 return apicid_core_offset(topo_info
) + apicid_core_width(topo_info
);
101 /* Bit offset of the Pkg_ID (socket ID) field */
102 static inline unsigned apicid_pkg_offset(X86CPUTopoInfo
*topo_info
)
104 return apicid_die_offset(topo_info
) + apicid_die_width(topo_info
);
108 * Make APIC ID for the CPU based on Pkg_ID, Core_ID, SMT_ID
110 * The caller must make sure core_id < nr_cores and smt_id < nr_threads.
112 static inline apic_id_t
x86_apicid_from_topo_ids(X86CPUTopoInfo
*topo_info
,
113 const X86CPUTopoIDs
*topo_ids
)
115 return (topo_ids
->pkg_id
<< apicid_pkg_offset(topo_info
)) |
116 (topo_ids
->die_id
<< apicid_die_offset(topo_info
)) |
117 (topo_ids
->core_id
<< apicid_core_offset(topo_info
)) |
122 * Calculate thread/core/package IDs for a specific topology,
123 * based on (contiguous) CPU index
125 static inline void x86_topo_ids_from_idx(X86CPUTopoInfo
*topo_info
,
127 X86CPUTopoIDs
*topo_ids
)
129 unsigned nr_dies
= topo_info
->dies_per_pkg
;
130 unsigned nr_cores
= topo_info
->cores_per_die
;
131 unsigned nr_threads
= topo_info
->threads_per_core
;
133 topo_ids
->pkg_id
= cpu_index
/ (nr_dies
* nr_cores
* nr_threads
);
134 topo_ids
->die_id
= cpu_index
/ (nr_cores
* nr_threads
) % nr_dies
;
135 topo_ids
->core_id
= cpu_index
/ nr_threads
% nr_cores
;
136 topo_ids
->smt_id
= cpu_index
% nr_threads
;
140 * Calculate thread/core/package IDs for a specific topology,
143 static inline void x86_topo_ids_from_apicid(apic_id_t apicid
,
144 X86CPUTopoInfo
*topo_info
,
145 X86CPUTopoIDs
*topo_ids
)
147 topo_ids
->smt_id
= apicid
&
148 ~(0xFFFFFFFFUL
<< apicid_smt_width(topo_info
));
150 (apicid
>> apicid_core_offset(topo_info
)) &
151 ~(0xFFFFFFFFUL
<< apicid_core_width(topo_info
));
153 (apicid
>> apicid_die_offset(topo_info
)) &
154 ~(0xFFFFFFFFUL
<< apicid_die_width(topo_info
));
155 topo_ids
->pkg_id
= apicid
>> apicid_pkg_offset(topo_info
);
159 * Make APIC ID for the CPU 'cpu_index'
161 * 'cpu_index' is a sequential, contiguous ID for the CPU.
163 static inline apic_id_t
x86_apicid_from_cpu_idx(X86CPUTopoInfo
*topo_info
,
166 X86CPUTopoIDs topo_ids
;
167 x86_topo_ids_from_idx(topo_info
, cpu_index
, &topo_ids
);
168 return x86_apicid_from_topo_ids(topo_info
, &topo_ids
);
171 #endif /* HW_I386_TOPOLOGY_H */