arch/x86/kernel/paravirt_patch_32.c

   1 #include <asm/paravirt.h>
   2
   3 DEF_NATIVE(pv_irq_ops, irq_disable, "cli");
   4 DEF_NATIVE(pv_irq_ops, irq_enable, "sti");
   5 DEF_NATIVE(pv_irq_ops, restore_fl, "push %eax; popf");
   6 DEF_NATIVE(pv_irq_ops, save_fl, "pushf; pop %eax");
   7 DEF_NATIVE(pv_cpu_ops, iret, "iret");
   8 DEF_NATIVE(pv_mmu_ops, read_cr2, "mov %cr2, %eax");
   9 DEF_NATIVE(pv_mmu_ops, write_cr3, "mov %eax, %cr3");
  10 DEF_NATIVE(pv_mmu_ops, read_cr3, "mov %cr3, %eax");
  11
  12 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
  13 DEF_NATIVE(pv_lock_ops, queued_spin_unlock, "movb $0, (%eax)");
  14 DEF_NATIVE(pv_lock_ops, vcpu_is_preempted, "xor %eax, %eax");
  15 #endif
  16
  17 unsigned paravirt_patch_ident_32(void *insnbuf, unsigned len)
  18 {
  19         /* arg in %eax, return in %eax */
  20         return 0;
  21 }
  22
  23 unsigned paravirt_patch_ident_64(void *insnbuf, unsigned len)
  24 {
  25         /* arg in %edx:%eax, return in %edx:%eax */
  26         return 0;
  27 }
  28
  29 extern bool pv_is_native_spin_unlock(void);
  30 extern bool pv_is_native_vcpu_is_preempted(void);
  31
  32 unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
  33                       unsigned long addr, unsigned len)
  34 {
  35         const unsigned char *start, *end;
  36         unsigned ret;
  37
  38 #define PATCH_SITE(ops, x)                                      \
  39                 case PARAVIRT_PATCH(ops.x):                     \
  40                         start = start_##ops##_##x;              \
  41                         end = end_##ops##_##x;                  \
  42                         goto patch_site
  43         switch (type) {
  44                 PATCH_SITE(pv_irq_ops, irq_disable);
  45                 PATCH_SITE(pv_irq_ops, irq_enable);
  46                 PATCH_SITE(pv_irq_ops, restore_fl);
  47                 PATCH_SITE(pv_irq_ops, save_fl);
  48                 PATCH_SITE(pv_cpu_ops, iret);
  49                 PATCH_SITE(pv_mmu_ops, read_cr2);
  50                 PATCH_SITE(pv_mmu_ops, read_cr3);
  51                 PATCH_SITE(pv_mmu_ops, write_cr3);
  52 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
  53                 case PARAVIRT_PATCH(pv_lock_ops.queued_spin_unlock):
  54                         if (pv_is_native_spin_unlock()) {
  55                                 start = start_pv_lock_ops_queued_spin_unlock;
  56                                 end   = end_pv_lock_ops_queued_spin_unlock;
  57                                 goto patch_site;
  58                         }
  59                         goto patch_default;
  60
  61                 case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):
  62                         if (pv_is_native_vcpu_is_preempted()) {
  63                                 start = start_pv_lock_ops_vcpu_is_preempted;
  64                                 end   = end_pv_lock_ops_vcpu_is_preempted;
  65                                 goto patch_site;
  66                         }
  67                         goto patch_default;
  68 #endif
  69
  70         default:
  71 patch_default: __maybe_unused
  72                 ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
  73                 break;
  74
  75 patch_site:
  76                 ret = paravirt_patch_insns(ibuf, len, start, end);
  77                 break;
  78         }
  79 #undef PATCH_SITE
  80         return ret;
  81 }