summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/cpu/addon_cpuid_features.c
blob: 6882a735d9c0ad70b0c6386d11f53d5d50673d40 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
/*
 *	Routines to indentify additional cpu features that are scattered in
 *	cpuid space.
 */
#include <linux/cpu.h>

#include <asm/pat.h>
#include <asm/processor.h>

#include <asm/apic.h>

struct cpuid_bit {
	u16 feature;
	u8 reg;
	u8 bit;
	u32 level;
};

enum cpuid_regs {
	CR_EAX = 0,
	CR_ECX,
	CR_EDX,
	CR_EBX
};

void __cpuinit init_scattered_cpuid_features(struct cpuinfo_x86 *c)
{
	u32 max_level;
	u32 regs[4];
	const struct cpuid_bit *cb;

	static const struct cpuid_bit cpuid_bits[] = {
		{ X86_FEATURE_IDA, CR_EAX, 1, 0x00000006 },
		{ 0, 0, 0, 0 }
	};

	for (cb = cpuid_bits; cb->feature; cb++) {

		/* Verify that the level is valid */
		max_level = cpuid_eax(cb->level & 0xffff0000);
		if (max_level < cb->level ||
		    max_level > (cb->level | 0xffff))
			continue;

		cpuid(cb->level, &regs[CR_EAX], &regs[CR_EBX],
			&regs[CR_ECX], &regs[CR_EDX]);

		if (regs[cb->reg] & (1 << cb->bit))
			set_cpu_cap(c, cb->feature);
	}
}

/* leaf 0xb SMT level */
#define SMT_LEVEL	0

/* leaf 0xb sub-leaf types */
#define INVALID_TYPE	0
#define SMT_TYPE	1
#define CORE_TYPE	2

#define LEAFB_SUBTYPE(ecx)		(((ecx) >> 8) & 0xff)
#define BITS_SHIFT_NEXT_LEVEL(eax)	((eax) & 0x1f)
#define LEVEL_MAX_SIBLINGS(ebx)		((ebx) & 0xffff)

/*
 * Check for extended topology enumeration cpuid leaf 0xb and if it
 * exists, use it for populating initial_apicid and cpu topology
 * detection.
 */
void __cpuinit 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;
	unsigned int core_select_mask, core_level_siblings;

	if (c->cpuid_level < 0xb)
		return;

	cpuid_count(0xb, SMT_LEVEL, &eax, &ebx, &ecx, &edx);

	/*
	 * check if the cpuid leaf 0xb is actually implemented.
	 */
	if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE))
		return;

	set_cpu_cap(c, X86_FEATURE_XTOPOLOGY);

	/*
	 * initial apic id, which also represents 32-bit extended x2apic id.
	 */
	c->initial_apicid = edx;

	/*
	 * Populate HT related information from sub-leaf level 0.
	 */
	core_level_siblings = smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
	core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);

	sub_index = 1;
	do {
		cpuid_count(0xb, 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);
			break;
		}

		sub_index++;
	} while (LEAFB_SUBTYPE(ecx) != INVALID_TYPE);

	core_select_mask = (~(-1 << core_plus_mask_width)) >> ht_mask_width;

	c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, ht_mask_width)
						 & core_select_mask;
	c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, core_plus_mask_width);
	/*
	 * Reinit the apicid, now that we have extended initial_apicid.
	 */
	c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);

	c->x86_max_cores = (core_level_siblings / smp_num_siblings);


	printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",
	       c->phys_proc_id);
	if (c->x86_max_cores > 1)
		printk(KERN_INFO  "CPU: Processor Core ID: %d\n",
		       c->cpu_core_id);
	return;
#endif
}