GNU Linux-libre 4.14.266-gnu1
[releases.git] / arch / x86 / kernel / paravirt_patch_32.c
1 // SPDX-License-Identifier: GPL-2.0
2 #include <asm/paravirt.h>
3
4 DEF_NATIVE(pv_irq_ops, irq_disable, "cli");
5 DEF_NATIVE(pv_irq_ops, irq_enable, "sti");
6 DEF_NATIVE(pv_irq_ops, restore_fl, "push %eax; popf");
7 DEF_NATIVE(pv_irq_ops, save_fl, "pushf; pop %eax");
8 DEF_NATIVE(pv_cpu_ops, iret, "iret");
9 DEF_NATIVE(pv_mmu_ops, read_cr2, "mov %cr2, %eax");
10 DEF_NATIVE(pv_mmu_ops, write_cr3, "mov %eax, %cr3");
11 DEF_NATIVE(pv_mmu_ops, read_cr3, "mov %cr3, %eax");
12
13 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
14 DEF_NATIVE(pv_lock_ops, queued_spin_unlock, "movb $0, (%eax)");
15 DEF_NATIVE(pv_lock_ops, vcpu_is_preempted, "xor %eax, %eax");
16 #endif
17
18 unsigned paravirt_patch_ident_32(void *insnbuf, unsigned len)
19 {
20         /* arg in %eax, return in %eax */
21         return 0;
22 }
23
24 unsigned paravirt_patch_ident_64(void *insnbuf, unsigned len)
25 {
26         /* arg in %edx:%eax, return in %edx:%eax */
27         return 0;
28 }
29
30 extern bool pv_is_native_spin_unlock(void);
31 extern bool pv_is_native_vcpu_is_preempted(void);
32
33 unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
34                       unsigned long addr, unsigned len)
35 {
36         const unsigned char *start, *end;
37         unsigned ret;
38
39 #define PATCH_SITE(ops, x)                                      \
40                 case PARAVIRT_PATCH(ops.x):                     \
41                         start = start_##ops##_##x;              \
42                         end = end_##ops##_##x;                  \
43                         goto patch_site
44         switch (type) {
45                 PATCH_SITE(pv_irq_ops, irq_disable);
46                 PATCH_SITE(pv_irq_ops, irq_enable);
47                 PATCH_SITE(pv_irq_ops, restore_fl);
48                 PATCH_SITE(pv_irq_ops, save_fl);
49                 PATCH_SITE(pv_cpu_ops, iret);
50                 PATCH_SITE(pv_mmu_ops, read_cr2);
51                 PATCH_SITE(pv_mmu_ops, read_cr3);
52                 PATCH_SITE(pv_mmu_ops, write_cr3);
53 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
54                 case PARAVIRT_PATCH(pv_lock_ops.queued_spin_unlock):
55                         if (pv_is_native_spin_unlock()) {
56                                 start = start_pv_lock_ops_queued_spin_unlock;
57                                 end   = end_pv_lock_ops_queued_spin_unlock;
58                                 goto patch_site;
59                         }
60                         goto patch_default;
61
62                 case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):
63                         if (pv_is_native_vcpu_is_preempted()) {
64                                 start = start_pv_lock_ops_vcpu_is_preempted;
65                                 end   = end_pv_lock_ops_vcpu_is_preempted;
66                                 goto patch_site;
67                         }
68                         goto patch_default;
69 #endif
70
71         default:
72 patch_default: __maybe_unused
73                 ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
74                 break;
75
76 patch_site:
77                 ret = paravirt_patch_insns(ibuf, len, start, end);
78                 break;
79         }
80 #undef PATCH_SITE
81         return ret;
82 }