/*
* x86 CPU topology data structures and functions
*
* Copyright (c) 2012 Red Hat Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef HW_I386_TOPOLOGY_H
#define HW_I386_TOPOLOGY_H
/* This file implements the APIC-ID-based CPU topology enumeration logic,
* documented at the following document:
* Intel® 64 Architecture Processor Topology Enumeration
* http://software.intel.com/en-us/articles/intel-64-architecture-processor-topology-enumeration/
*
* This code should be compatible with AMD's "Extended Method" described at:
* AMD CPUID Specification (Publication #25481)
* Section 3: Multiple Core Calcuation
* as long as:
* nr_threads is set to 1;
* OFFSET_IDX is assumed to be 0;
* CPUID Fn8000_0008_ECX[ApicIdCoreIdSize[3:0]] is set to apicid_core_width().
*/
#include "qemu/bitops.h"
/* APIC IDs can be 32-bit, but beware: APIC IDs > 255 require x2APIC support
*/
typedef uint32_t apic_id_t;
typedef struct X86CPUTopoIDs {
unsigned pkg_id;
unsigned die_id;
unsigned core_id;
unsigned smt_id;
} X86CPUTopoIDs;
typedef struct X86CPUTopoInfo {
unsigned dies_per_pkg;
unsigned cores_per_die;
unsigned threads_per_core;
} X86CPUTopoInfo;
/* Return the bit width needed for 'count' IDs
*/
static unsigned apicid_bitwidth_for_count(unsigned count)
{
g_assert(count >= 1);
count -= 1;
return count ? 32 - clz32(count) : 0;
}
/* Bit width of the SMT_ID (thread ID) field on the APIC ID
*/
static inline unsigned apicid_smt_width(X86CPUTopoInfo *topo_info)
{
return apicid_bitwidth_for_count(topo_info->threads_per_core);
}
/* Bit width of the Core_ID field
*/
static inline unsigned apicid_core_width(X86CPUTopoInfo *topo_info)
{
return apicid_bitwidth_for_count(topo_info->cores_per_die);
}
/* Bit width of the Die_ID field */
static inline unsigned apicid_die_width(X86CPUTopoInfo *topo_info)
{
return apicid_bitwidth_for_count(topo_info->dies_per_pkg);
}
/* Bit offset of the Core_ID field
*/
static inline unsigned apicid_core_offset(X86CPUTopoInfo *topo_info)
{
return apicid_smt_width(topo_info);
}
/* Bit offset of the Die_ID field */
static inline unsigned apicid_die_offset(X86CPUTopoInfo *topo_info)
{
return apicid_core_offset(topo_info) + apicid_core_width(topo_info);
}
/* Bit offset of the Pkg_ID (socket ID) field
*/
static inline unsigned apicid_pkg_offset(X86CPUTopoInfo *topo_info)
{
return apicid_die_offset(topo_info) + apicid_die_width(topo_info);
}
/* Make APIC ID for the CPU based on Pkg_ID, Core_ID, SMT_ID
*
* The caller must make sure core_id < nr_cores and smt_id < nr_threads.
*/
static inline apic_id_t x86_apicid_from_topo_ids(X86CPUTopoInfo *topo_info,
const X86CPUTopoIDs *topo_ids)
{
return (topo_ids->pkg_id << apicid_pkg_offset(topo_info)) |
(topo_ids->die_id << apicid_die_offset(topo_info)) |
(topo_ids->core_id << apicid_core_offset(topo_info)) |
topo_ids->smt_id;
}
/* Calculate thread/core/package IDs for a specific topology,
* based on (contiguous) CPU index
*/
static inline void x86_topo_ids_from_idx(X86CPUTopoInfo *topo_info,
unsigned cpu_index,
X86CPUTopoIDs *topo_ids)
{
unsigned nr_dies = topo_info->dies_per_pkg;
unsigned nr_cores = topo_info->cores_per_die;
unsigned nr_threads = topo_info->threads_per_core;
topo_ids->pkg_id = cpu_index / (nr_dies * nr_cores * nr_threads);
topo_ids->die_id = cpu_index / (nr_cores * nr_threads) % nr_dies;
topo_ids->core_id = cpu_index / nr_threads % nr_cores;
topo_ids->smt_id = cpu_index % nr_threads;
}
/* Calculate thread/core/package IDs for a specific topology,
* based on APIC ID
*/
static inline void x86_topo_ids_from_apicid(apic_id_t apicid,
X86CPUTopoInfo *topo_info,
X86CPUTopoIDs *topo_ids)
{
topo_ids->smt_id = apicid &
~(0xFFFFFFFFUL << apicid_smt_width(topo_info));
topo_ids->core_id =
(apicid >> apicid_core_offset(topo_info)) &
~(0xFFFFFFFFUL << apicid_core_width(topo_info));
topo_ids->die_id =
(apicid >> apicid_die_offset(topo_info)) &
~(0xFFFFFFFFUL << apicid_die_width(topo_info));
topo_ids->pkg_id = apicid >> apicid_pkg_offset(topo_info);
}
/* Make APIC ID for the CPU 'cpu_index'
*
* 'cpu_index' is a sequential, contiguous ID for the CPU.
*/
static inline apic_id_t x86_apicid_from_cpu_idx(X86CPUTopoInfo *topo_info,
unsigned cpu_index)
{
X86CPUTopoIDs topo_ids;
x86_topo_ids_from_idx(topo_info, cpu_index, &topo_ids);
return x86_apicid_from_topo_ids(topo_info, &topo_ids);
}
#endif /* HW_I386_TOPOLOGY_H */
