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