1/*
 2 * Check for extended topology enumeration cpuid leaf 0xb and if it
 3 * exists, use it for populating initial_apicid and cpu topology
 4 * detection.
 5 */
 6
 7#include <linux/cpu.h>
 8#include <asm/apic.h>
 9#include <asm/pat.h>
10#include <asm/processor.h>
11
12/* leaf 0xb SMT level */
13#define SMT_LEVEL	0
14
15/* leaf 0xb sub-leaf types */
16#define INVALID_TYPE	0
17#define SMT_TYPE	1
18#define CORE_TYPE	2
19
20#define LEAFB_SUBTYPE(ecx)		(((ecx) >> 8) & 0xff)
21#define BITS_SHIFT_NEXT_LEVEL(eax)	((eax) & 0x1f)
22#define LEVEL_MAX_SIBLINGS(ebx)		((ebx) & 0xffff)
23
24/*
25 * Check for extended topology enumeration cpuid leaf 0xb and if it
26 * exists, use it for populating initial_apicid and cpu topology
27 * detection.
28 */
29void __cpuinit detect_extended_topology(struct cpuinfo_x86 *c)
30{
31#ifdef CONFIG_SMP
32	unsigned int eax, ebx, ecx, edx, sub_index;
33	unsigned int ht_mask_width, core_plus_mask_width;
34	unsigned int core_select_mask, core_level_siblings;
35	static bool printed;
36
37	if (c->cpuid_level < 0xb)
38		return;
39
40	cpuid_count(0xb, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
41
42	/*
43	 * check if the cpuid leaf 0xb is actually implemented.
44	 */
45	if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE))
46		return;
47
48	set_cpu_cap(c, X86_FEATURE_XTOPOLOGY);
49
50	/*
51	 * initial apic id, which also represents 32-bit extended x2apic id.
52	 */
53	c->initial_apicid = edx;
54
55	/*
56	 * Populate HT related information from sub-leaf level 0.
57	 */
58	core_level_siblings = smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
59	core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
60
61	sub_index = 1;
62	do {
63		cpuid_count(0xb, sub_index, &eax, &ebx, &ecx, &edx);
64
65		/*
66		 * Check for the Core type in the implemented sub leaves.
67		 */
68		if (LEAFB_SUBTYPE(ecx) == CORE_TYPE) {
69			core_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
70			core_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
71			break;
72		}
73
74		sub_index++;
75	} while (LEAFB_SUBTYPE(ecx) != INVALID_TYPE);
76
77	core_select_mask = (~(-1 << core_plus_mask_width)) >> ht_mask_width;
78
79	c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, ht_mask_width)
80						 & core_select_mask;
81	c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, core_plus_mask_width);
82	/*
83	 * Reinit the apicid, now that we have extended initial_apicid.
84	 */
85	c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
86
87	c->x86_max_cores = (core_level_siblings / smp_num_siblings);
88
89	if (!printed) {
90		printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",
91		       c->phys_proc_id);
92		if (c->x86_max_cores > 1)
93			printk(KERN_INFO  "CPU: Processor Core ID: %d\n",
94			       c->cpu_core_id);
95		printed = 1;
96	}
97	return;
98#endif
99}

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Check for extended topology enumeration cpuid leaf 0xb and if it
  4 * exists, use it for populating initial_apicid and cpu topology
  5 * detection.
  6 */
  7
  8#include <linux/cpu.h>
  9#include <asm/apic.h>
 10#include <asm/pat.h>
 11#include <asm/processor.h>
 12
 13/* leaf 0xb SMT level */
 14#define SMT_LEVEL	0
 15
 16/* leaf 0xb sub-leaf types */
 17#define INVALID_TYPE	0
 18#define SMT_TYPE	1
 19#define CORE_TYPE	2
 20
 21#define LEAFB_SUBTYPE(ecx)		(((ecx) >> 8) & 0xff)
 22#define BITS_SHIFT_NEXT_LEVEL(eax)	((eax) & 0x1f)
 23#define LEVEL_MAX_SIBLINGS(ebx)		((ebx) & 0xffff)
 24
 25/*
 26 * Check for extended topology enumeration cpuid leaf 0xb and if it
 27 * exists, use it for populating initial_apicid and cpu topology
 28 * detection.
 29 */
 30void detect_extended_topology(struct cpuinfo_x86 *c)
 31{
 32#ifdef CONFIG_SMP
 33	unsigned int eax, ebx, ecx, edx, sub_index;
 34	unsigned int ht_mask_width, core_plus_mask_width;
 35	unsigned int core_select_mask, core_level_siblings;
 36	static bool printed;
 37
 38	if (c->cpuid_level < 0xb)
 39		return;
 40
 41	cpuid_count(0xb, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
 42
 43	/*
 44	 * check if the cpuid leaf 0xb is actually implemented.
 45	 */
 46	if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE))
 47		return;
 48
 49	set_cpu_cap(c, X86_FEATURE_XTOPOLOGY);
 50
 51	/*
 52	 * initial apic id, which also represents 32-bit extended x2apic id.
 53	 */
 54	c->initial_apicid = edx;
 55
 56	/*
 57	 * Populate HT related information from sub-leaf level 0.
 58	 */
 59	core_level_siblings = smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
 60	core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
 61
 62	sub_index = 1;
 63	do {
 64		cpuid_count(0xb, sub_index, &eax, &ebx, &ecx, &edx);
 65
 66		/*
 67		 * Check for the Core type in the implemented sub leaves.
 68		 */
 69		if (LEAFB_SUBTYPE(ecx) == CORE_TYPE) {
 70			core_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
 71			core_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
 72			break;
 73		}
 74
 75		sub_index++;
 76	} while (LEAFB_SUBTYPE(ecx) != INVALID_TYPE);
 77
 78	core_select_mask = (~(-1 << core_plus_mask_width)) >> ht_mask_width;
 79
 80	c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, ht_mask_width)
 81						 & core_select_mask;
 82	c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, core_plus_mask_width);
 83	/*
 84	 * Reinit the apicid, now that we have extended initial_apicid.
 85	 */
 86	c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
 87
 88	c->x86_max_cores = (core_level_siblings / smp_num_siblings);
 89
 90	if (!printed) {
 91		pr_info("CPU: Physical Processor ID: %d\n",
 92		       c->phys_proc_id);
 93		if (c->x86_max_cores > 1)
 94			pr_info("CPU: Processor Core ID: %d\n",
 95			       c->cpu_core_id);
 96		printed = 1;
 97	}
 98	return;
 99#endif
100}