acpi_pad: build only on X86
[linux-2.6/linux-acpi-2.6.git] / arch / x86 / kernel / cpu / addon_cpuid_features.c
blobc965e5212714ee66cfe04e847544e213f44a7b2d
1 /*
2 * Routines to indentify additional cpu features that are scattered in
3 * cpuid space.
4 */
5 #include <linux/cpu.h>
7 #include <asm/pat.h>
8 #include <asm/processor.h>
10 #include <asm/apic.h>
12 struct cpuid_bit {
13 u16 feature;
14 u8 reg;
15 u8 bit;
16 u32 level;
19 enum cpuid_regs {
20 CR_EAX = 0,
21 CR_ECX,
22 CR_EDX,
23 CR_EBX
26 void __cpuinit init_scattered_cpuid_features(struct cpuinfo_x86 *c)
28 u32 max_level;
29 u32 regs[4];
30 const struct cpuid_bit *cb;
32 static const struct cpuid_bit __cpuinitconst cpuid_bits[] = {
33 { X86_FEATURE_IDA, CR_EAX, 1, 0x00000006 },
34 { X86_FEATURE_ARAT, CR_EAX, 2, 0x00000006 },
35 { 0, 0, 0, 0 }
38 for (cb = cpuid_bits; cb->feature; cb++) {
40 /* Verify that the level is valid */
41 max_level = cpuid_eax(cb->level & 0xffff0000);
42 if (max_level < cb->level ||
43 max_level > (cb->level | 0xffff))
44 continue;
46 cpuid(cb->level, &regs[CR_EAX], &regs[CR_EBX],
47 &regs[CR_ECX], &regs[CR_EDX]);
49 if (regs[cb->reg] & (1 << cb->bit))
50 set_cpu_cap(c, cb->feature);
54 /* leaf 0xb SMT level */
55 #define SMT_LEVEL 0
57 /* leaf 0xb sub-leaf types */
58 #define INVALID_TYPE 0
59 #define SMT_TYPE 1
60 #define CORE_TYPE 2
62 #define LEAFB_SUBTYPE(ecx) (((ecx) >> 8) & 0xff)
63 #define BITS_SHIFT_NEXT_LEVEL(eax) ((eax) & 0x1f)
64 #define LEVEL_MAX_SIBLINGS(ebx) ((ebx) & 0xffff)
67 * Check for extended topology enumeration cpuid leaf 0xb and if it
68 * exists, use it for populating initial_apicid and cpu topology
69 * detection.
71 void __cpuinit detect_extended_topology(struct cpuinfo_x86 *c)
73 #ifdef CONFIG_SMP
74 unsigned int eax, ebx, ecx, edx, sub_index;
75 unsigned int ht_mask_width, core_plus_mask_width;
76 unsigned int core_select_mask, core_level_siblings;
78 if (c->cpuid_level < 0xb)
79 return;
81 cpuid_count(0xb, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
84 * check if the cpuid leaf 0xb is actually implemented.
86 if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE))
87 return;
89 set_cpu_cap(c, X86_FEATURE_XTOPOLOGY);
92 * initial apic id, which also represents 32-bit extended x2apic id.
94 c->initial_apicid = edx;
97 * Populate HT related information from sub-leaf level 0.
99 core_level_siblings = smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
100 core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
102 sub_index = 1;
103 do {
104 cpuid_count(0xb, sub_index, &eax, &ebx, &ecx, &edx);
107 * Check for the Core type in the implemented sub leaves.
109 if (LEAFB_SUBTYPE(ecx) == CORE_TYPE) {
110 core_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
111 core_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
112 break;
115 sub_index++;
116 } while (LEAFB_SUBTYPE(ecx) != INVALID_TYPE);
118 core_select_mask = (~(-1 << core_plus_mask_width)) >> ht_mask_width;
120 c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, ht_mask_width)
121 & core_select_mask;
122 c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, core_plus_mask_width);
124 * Reinit the apicid, now that we have extended initial_apicid.
126 c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
128 c->x86_max_cores = (core_level_siblings / smp_num_siblings);
131 printk(KERN_INFO "CPU: Physical Processor ID: %d\n",
132 c->phys_proc_id);
133 if (c->x86_max_cores > 1)
134 printk(KERN_INFO "CPU: Processor Core ID: %d\n",
135 c->cpu_core_id);
136 return;
137 #endif