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