arch/x86/kernel/cpu/addon_cpuid_features.c

   1 /*
   2  *      Routines to indentify additional cpu features that are scattered in
   3  *      cpuid space.
   4  */
   5 #include <linux/cpu.h>
   6
   7 #include <asm/pat.h>
   8 #include <asm/processor.h>
   9
  10 #include <asm/apic.h>
  11
  12 struct cpuid_bit {
  13         u16 feature;
  14         u8 reg;
  15         u8 bit;
  16         u32 level;
  17 };
  18
  19 enum cpuid_regs {
  20         CR_EAX = 0,
  21         CR_ECX,
  22         CR_EDX,
  23         CR_EBX
  24 };
  25
  26 void __cpuinit init_scattered_cpuid_features(struct cpuinfo_x86 *c)
  27 {
  28         u32 max_level;
  29         u32 regs[4];
  30         const struct cpuid_bit *cb;
  31
  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                 { X86_FEATURE_APERFMPERF,       CR_ECX, 0, 0x00000006 },
  36                 { X86_FEATURE_CPB,              CR_EDX, 9, 0x80000007 },
  37                 { X86_FEATURE_NPT,              CR_EDX, 0, 0x8000000a },
  38                 { X86_FEATURE_LBRV,             CR_EDX, 1, 0x8000000a },
  39                 { X86_FEATURE_SVML,             CR_EDX, 2, 0x8000000a },
  40                 { X86_FEATURE_NRIPS,            CR_EDX, 3, 0x8000000a },
  41                 { 0, 0, 0, 0 }
  42         };
  43
  44         for (cb = cpuid_bits; cb->feature; cb++) {
  45
  46                 /* Verify that the level is valid */
  47                 max_level = cpuid_eax(cb->level & 0xffff0000);
  48                 if (max_level < cb->level ||
  49                     max_level > (cb->level | 0xffff))
  50                         continue;
  51
  52                 cpuid(cb->level, &regs[CR_EAX], &regs[CR_EBX],
  53                         &regs[CR_ECX], &regs[CR_EDX]);
  54
  55                 if (regs[cb->reg] & (1 << cb->bit))
  56                         set_cpu_cap(c, cb->feature);
  57         }
  58 }
  59
  60 /* leaf 0xb SMT level */
  61 #define SMT_LEVEL       0
  62
  63 /* leaf 0xb sub-leaf types */
  64 #define INVALID_TYPE    0
  65 #define SMT_TYPE        1
  66 #define CORE_TYPE       2
  67
  68 #define LEAFB_SUBTYPE(ecx)              (((ecx) >> 8) & 0xff)
  69 #define BITS_SHIFT_NEXT_LEVEL(eax)      ((eax) & 0x1f)
  70 #define LEVEL_MAX_SIBLINGS(ebx)         ((ebx) & 0xffff)
  71
  72 /*
  73  * Check for extended topology enumeration cpuid leaf 0xb and if it
  74  * exists, use it for populating initial_apicid and cpu topology
  75  * detection.
  76  */
  77 void __cpuinit detect_extended_topology(struct cpuinfo_x86 *c)
  78 {
  79 #ifdef CONFIG_SMP
  80         unsigned int eax, ebx, ecx, edx, sub_index;
  81         unsigned int ht_mask_width, core_plus_mask_width;
  82         unsigned int core_select_mask, core_level_siblings;
  83         static bool printed;
  84
  85         if (c->cpuid_level < 0xb)
  86                 return;
  87
  88         cpuid_count(0xb, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
  89
  90         /*
  91          * check if the cpuid leaf 0xb is actually implemented.
  92          */
  93         if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE))
  94                 return;
  95
  96         set_cpu_cap(c, X86_FEATURE_XTOPOLOGY);
  97
  98         /*
  99          * initial apic id, which also represents 32-bit extended x2apic id.
 100          */
 101         c->initial_apicid = edx;
 102
 103         /*
 104          * Populate HT related information from sub-leaf level 0.
 105          */
 106         core_level_siblings = smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
 107         core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
 108
 109         sub_index = 1;
 110         do {
 111                 cpuid_count(0xb, sub_index, &eax, &ebx, &ecx, &edx);
 112
 113                 /*
 114                  * Check for the Core type in the implemented sub leaves.
 115                  */
 116                 if (LEAFB_SUBTYPE(ecx) == CORE_TYPE) {
 117                         core_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
 118                         core_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
 119                         break;
 120                 }
 121
 122                 sub_index++;
 123         } while (LEAFB_SUBTYPE(ecx) != INVALID_TYPE);
 124
 125         core_select_mask = (~(-1 << core_plus_mask_width)) >> ht_mask_width;
 126
 127         c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, ht_mask_width)
 128                                                  & core_select_mask;
 129         c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, core_plus_mask_width);
 130         /*
 131          * Reinit the apicid, now that we have extended initial_apicid.
 132          */
 133         c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
 134
 135         c->x86_max_cores = (core_level_siblings / smp_num_siblings);
 136
 137         if (!printed) {
 138                 printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",
 139                        c->phys_proc_id);
 140                 if (c->x86_max_cores > 1)
 141                         printk(KERN_INFO  "CPU: Processor Core ID: %d\n",
 142                                c->cpu_core_id);
 143                 printed = 1;
 144         }
 145         return;
 146 #endif
 147 }