Merge tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...
[linux-2.6-block.git] / arch / x86 / kernel / cpu / topology.c
CommitLineData
1d67953f 1/*
2decb194
PA
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.
1d67953f 5 */
1d67953f 6
2decb194
PA
7#include <linux/cpu.h>
8#include <asm/apic.h>
8d4a4300 9#include <asm/pat.h>
1d67953f
VP
10#include <asm/processor.h>
11
bbb65d2d
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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 */
148f9bb8 29void detect_extended_topology(struct cpuinfo_x86 *c)
bbb65d2d 30{
3e5095d1 31#ifdef CONFIG_SMP
bbb65d2d
SS
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;
2eaad1fd 35 static bool printed;
bbb65d2d
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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
cb8cc442 79 c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, ht_mask_width)
bbb65d2d 80 & core_select_mask;
cb8cc442 81 c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, core_plus_mask_width);
345077cd
SS
82 /*
83 * Reinit the apicid, now that we have extended initial_apicid.
84 */
cb8cc442 85 c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
d4c9a9f3 86
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87 c->x86_max_cores = (core_level_siblings / smp_num_siblings);
88
2eaad1fd 89 if (!printed) {
1b74dde7 90 pr_info("CPU: Physical Processor ID: %d\n",
2eaad1fd
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91 c->phys_proc_id);
92 if (c->x86_max_cores > 1)
1b74dde7 93 pr_info("CPU: Processor Core ID: %d\n",
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94 c->cpu_core_id);
95 printed = 1;
96 }
bbb65d2d 97 return;
11c231a9 98#endif
bbb65d2d 99}