LXR linux/arch/x86/kernel/cpu/scattered.c

   1/*
   2 *      Routines to identify additional cpu features that are scattered in
   3 *      cpuid space.
   4 */
   5#include <linux/cpu.h>
   6
   7#include <asm/memtype.h>
   8#include <asm/apic.h>
   9#include <asm/processor.h>
  10
  11#include "cpu.h"
  12
  13struct cpuid_bit {
  14        u16 feature;
  15        u8 reg;
  16        u8 bit;
  17        u32 level;
  18        u32 sub_leaf;
  19};
  20
  21/*
  22 * Please keep the leaf sorted by cpuid_bit.level for faster search.
  23 * X86_FEATURE_MBA is supported by both Intel and AMD. But the CPUID
  24 * levels are different and there is a separate entry for each.
  25 */
  26static const struct cpuid_bit cpuid_bits[] = {
  27        { X86_FEATURE_APERFMPERF,       CPUID_ECX,  0, 0x00000006, 0 },
  28        { X86_FEATURE_EPB,              CPUID_ECX,  3, 0x00000006, 0 },
  29        { X86_FEATURE_CQM_LLC,          CPUID_EDX,  1, 0x0000000f, 0 },
  30        { X86_FEATURE_CQM_OCCUP_LLC,    CPUID_EDX,  0, 0x0000000f, 1 },
  31        { X86_FEATURE_CQM_MBM_TOTAL,    CPUID_EDX,  1, 0x0000000f, 1 },
  32        { X86_FEATURE_CQM_MBM_LOCAL,    CPUID_EDX,  2, 0x0000000f, 1 },
  33        { X86_FEATURE_CAT_L3,           CPUID_EBX,  1, 0x00000010, 0 },
  34        { X86_FEATURE_CAT_L2,           CPUID_EBX,  2, 0x00000010, 0 },
  35        { X86_FEATURE_CDP_L3,           CPUID_ECX,  2, 0x00000010, 1 },
  36        { X86_FEATURE_CDP_L2,           CPUID_ECX,  2, 0x00000010, 2 },
  37        { X86_FEATURE_MBA,              CPUID_EBX,  3, 0x00000010, 0 },
  38        { X86_FEATURE_PER_THREAD_MBA,   CPUID_ECX,  0, 0x00000010, 3 },
  39        { X86_FEATURE_SGX1,             CPUID_EAX,  0, 0x00000012, 0 },
  40        { X86_FEATURE_SGX2,             CPUID_EAX,  1, 0x00000012, 0 },
  41        { X86_FEATURE_HW_PSTATE,        CPUID_EDX,  7, 0x80000007, 0 },
  42        { X86_FEATURE_CPB,              CPUID_EDX,  9, 0x80000007, 0 },
  43        { X86_FEATURE_PROC_FEEDBACK,    CPUID_EDX, 11, 0x80000007, 0 },
  44        { X86_FEATURE_MBA,              CPUID_EBX,  6, 0x80000008, 0 },
  45        { 0, 0, 0, 0, 0 }
  46};
  47
  48void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
  49{
  50        u32 max_level;
  51        u32 regs[4];
  52        const struct cpuid_bit *cb;
  53
  54        for (cb = cpuid_bits; cb->feature; cb++) {
  55
  56                /* Verify that the level is valid */
  57                max_level = cpuid_eax(cb->level & 0xffff0000);
  58                if (max_level < cb->level ||
  59                    max_level > (cb->level | 0xffff))
  60                        continue;
  61
  62                cpuid_count(cb->level, cb->sub_leaf, &regs[CPUID_EAX],
  63                            &regs[CPUID_EBX], &regs[CPUID_ECX],
  64                            &regs[CPUID_EDX]);
  65
  66                if (regs[cb->reg] & (1 << cb->bit))
  67                        set_cpu_cap(c, cb->feature);
  68        }
  69}
  70