1 #ifndef __ARM_CPUERRATA_H__
2 #define __ARM_CPUERRATA_H__
3
4 #include <asm/cpufeature.h>
5 #include <asm/alternative.h>
6
7 void check_local_cpu_errata(void);
8 void enable_errata_workarounds(void);
9
10 #define CHECK_WORKAROUND_HELPER(erratum, feature, arch) \
11 static inline bool check_workaround_##erratum(void) \
12 { \
13 if ( !IS_ENABLED(arch) ) \
14 return false; \
15 else \
16 { \
17 register_t ret; \
18 \
19 asm_inline volatile ( \
20 ALTERNATIVE("mov %0, #0", \
21 "mov %0, #1", feature) \
22 : "=r" (ret) ); \
23 \
24 return unlikely(ret); \
25 } \
26 }
27
28 CHECK_WORKAROUND_HELPER(766422, ARM32_WORKAROUND_766422, CONFIG_ARM_32)
29 CHECK_WORKAROUND_HELPER(834220, ARM64_WORKAROUND_834220, CONFIG_ARM_64)
30 CHECK_WORKAROUND_HELPER(ssbd, ARM_SSBD, CONFIG_ARM_SSBD)
31 CHECK_WORKAROUND_HELPER(858921, ARM_WORKAROUND_858921,
32 CONFIG_ARM_ERRATUM_858921)
33
34 #undef CHECK_WORKAROUND_HELPER
35
36 enum ssbd_state
37 {
38 ARM_SSBD_UNKNOWN,
39 ARM_SSBD_FORCE_DISABLE,
40 ARM_SSBD_RUNTIME,
41 ARM_SSBD_FORCE_ENABLE,
42 ARM_SSBD_MITIGATED,
43 };
44
45 #ifdef CONFIG_ARM_SSBD
46
47 #include <asm/current.h>
48
49 extern enum ssbd_state ssbd_state;
50
get_ssbd_state(void)51 static inline enum ssbd_state get_ssbd_state(void)
52 {
53 return ssbd_state;
54 }
55
56 DECLARE_PER_CPU(register_t, ssbd_callback_required);
57
cpu_require_ssbd_mitigation(void)58 static inline bool cpu_require_ssbd_mitigation(void)
59 {
60 return this_cpu(ssbd_callback_required);
61 }
62
63 #else
64
cpu_require_ssbd_mitigation(void)65 static inline bool cpu_require_ssbd_mitigation(void)
66 {
67 return false;
68 }
69
get_ssbd_state(void)70 static inline enum ssbd_state get_ssbd_state(void)
71 {
72 return ARM_SSBD_UNKNOWN;
73 }
74
75 #endif
76
77 #endif /* __ARM_CPUERRATA_H__ */
78 /*
79 * Local variables:
80 * mode: C
81 * c-file-style: "BSD"
82 * c-basic-offset: 4
83 * indent-tabs-mode: nil
84 * End:
85 */
86