blob: dc136703566f3fb97cc77fde581a373a8688c909 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Check for extended topology enumeration cpuid leaf 0xb and if it
* exists, use it for populating initial_apicid and cpu topology
* detection.
*/
#include <linux/cpu.h>
#include <asm/apic.h>
#include <asm/memtype.h>
#include <asm/processor.h>
#include "cpu.h"
/* leaf 0xb SMT level */
#define SMT_LEVEL 0
/* extended topology sub-leaf types */
#define INVALID_TYPE 0
#define SMT_TYPE 1
#define CORE_TYPE 2
#define DIE_TYPE 5
#define LEAFB_SUBTYPE(ecx) (((ecx) >> 8) & 0xff)
#define BITS_SHIFT_NEXT_LEVEL(eax) ((eax) & 0x1f)
#define LEVEL_MAX_SIBLINGS(ebx) ((ebx) & 0xffff)
unsigned int __max_die_per_package __read_mostly = 1;
EXPORT_SYMBOL(__max_die_per_package);
#ifdef CONFIG_SMP
/*
* Check if given CPUID extended topology "leaf" is implemented
*/
static int check_extended_topology_leaf(int leaf)
{
unsigned int eax, ebx, ecx, edx;
cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE))
return -1;
return 0;
}
/*
* Return best CPUID Extended Topology Leaf supported
*/
static int detect_extended_topology_leaf(struct cpuinfo_x86 *c)
{
if (c->cpuid_level >= 0x1f) {
if (check_extended_topology_leaf(0x1f) == 0)
return 0x1f;
}
if (c->cpuid_level >= 0xb) {
if (check_extended_topology_leaf(0xb) == 0)
return 0xb;
}
return -1;
}
#endif
int detect_extended_topology_early(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_SMP
unsigned int eax, ebx, ecx, edx;
int leaf;
leaf = detect_extended_topology_leaf(c);
if (leaf < 0)
return -1;
set_cpu_cap(c, X86_FEATURE_XTOPOLOGY);
cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
/*
* initial apic id, which also represents 32-bit extended x2apic id.
*/
c->topo.initial_apicid = edx;
smp_num_siblings = max_t(int, smp_num_siblings, LEVEL_MAX_SIBLINGS(ebx));
#endif
return 0;
}
/*
* Check for extended topology enumeration cpuid leaf, and if it
* exists, use it for populating initial_apicid and cpu topology
* detection.
*/
int detect_extended_topology(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_SMP
unsigned int eax, ebx, ecx, edx, sub_index;
unsigned int ht_mask_width, core_plus_mask_width, die_plus_mask_width;
unsigned int core_select_mask, core_level_siblings;
unsigned int die_select_mask, die_level_siblings;
unsigned int pkg_mask_width;
bool die_level_present = false;
int leaf;
leaf = detect_extended_topology_leaf(c);
if (leaf < 0)
return -1;
/*
* Populate HT related information from sub-leaf level 0.
*/
cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
c->topo.initial_apicid = edx;
core_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
smp_num_siblings = max_t(int, smp_num_siblings, LEVEL_MAX_SIBLINGS(ebx));
core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
die_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
pkg_mask_width = die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
sub_index = 1;
while (true) {
cpuid_count(leaf, sub_index, &eax, &ebx, &ecx, &edx);
/*
* Check for the Core type in the implemented sub leaves.
*/
if (LEAFB_SUBTYPE(ecx) == CORE_TYPE) {
core_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
core_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
die_level_siblings = core_level_siblings;
die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
}
if (LEAFB_SUBTYPE(ecx) == DIE_TYPE) {
die_level_present = true;
die_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
}
if (LEAFB_SUBTYPE(ecx) != INVALID_TYPE)
pkg_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
else
break;
sub_index++;
}
core_select_mask = (~(-1 << pkg_mask_width)) >> ht_mask_width;
die_select_mask = (~(-1 << die_plus_mask_width)) >>
core_plus_mask_width;
c->topo.core_id = apic->phys_pkg_id(c->topo.initial_apicid,
ht_mask_width) & core_select_mask;
if (die_level_present) {
c->topo.die_id = apic->phys_pkg_id(c->topo.initial_apicid,
core_plus_mask_width) & die_select_mask;
}
c->topo.pkg_id = apic->phys_pkg_id(c->topo.initial_apicid, pkg_mask_width);
/*
* Reinit the apicid, now that we have extended initial_apicid.
*/
c->topo.apicid = apic->phys_pkg_id(c->topo.initial_apicid, 0);
c->x86_max_cores = (core_level_siblings / smp_num_siblings);
__max_die_per_package = (die_level_siblings / core_level_siblings);
#endif
return 0;
}