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2 //
3 // @APPLE_OSREFERENCE_LICENSE_HEADER_START@
4 //
5 // This file contains Original Code and/or Modifications of Original Code
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8 // compliance with the License. The rights granted to you under the License
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11 // circumvent, violate, or enable the circumvention or violation of, any
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16 //
17 // The Original Code and all software distributed under the License are
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19 // EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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25 // @APPLE_OSREFERENCE_LICENSE_HEADER_END@
26
27 #include <kern/cpc.h>
28 #include <stdbool.h>
29 #include <kern/assert.h>
30 #include <kern/debug.h>
31 #include <os/atomic.h>
32 #include <os/atomic_private.h>
33
34 #if __arm64__
35 #include <arm64/cpc_arm64.h>
36 #endif // __arm64__
37
38 #pragma mark - Ownership
39
40 #if CONFIG_CPU_COUNTERS
41 static const char * _Atomic _cpc_hw_owners[CPC_HW_COUNT] = { NULL };
42 #endif // CONFIG_CPU_COUNTERS
43
44 __result_use_check bool
cpc_hw_acquire(cpc_hw_t hw,const char * owner_name)45 cpc_hw_acquire(cpc_hw_t hw, const char *owner_name)
46 {
47 #if CONFIG_CPU_COUNTERS
48 assert3u(hw, <, CPC_HW_COUNT);
49 extern int kpc_get_force_all_ctrs(void);
50 if (hw == CPC_HW_CPMU && kpc_get_force_all_ctrs()) {
51 return false;
52 }
53 return os_atomic_cmpxchg(&_cpc_hw_owners[hw], NULL, owner_name, acq_rel);
54 #else // CONFIG_CPU_COUNTERS
55 #pragma unused(hw, owner_name)
56 return false;
57 #endif // !CONFIG_CPU_COUNTERS
58 }
59
60 bool
cpc_hw_in_use(cpc_hw_t hw)61 cpc_hw_in_use(cpc_hw_t hw)
62 {
63 #if CONFIG_CPU_COUNTERS
64 assert3u(hw, <, CPC_HW_COUNT);
65 return os_atomic_load(&_cpc_hw_owners[hw], acquire) != NULL;
66 #else // CONFIG_CPU_COUNTERS
67 #pragma unused(hw)
68 return false;
69 #endif // !CONFIG_CPU_COUNTERS
70 }
71
72 void
cpc_hw_release(cpc_hw_t hw,const char * owner_name)73 cpc_hw_release(cpc_hw_t hw, const char *owner_name)
74 {
75 #if CONFIG_CPU_COUNTERS
76 assert3u(hw, <, CPC_HW_COUNT);
77 if (!os_atomic_cmpxchg(&_cpc_hw_owners[hw], owner_name, NULL, acq_rel)) {
78 panic("CPC: unpaired HW release: %s on %u", owner_name, hw);
79 }
80 #else // CONFIG_CPU_COUNTERS
81 #pragma unused(hw, owner_name)
82 #endif // !CONFIG_CPU_COUNTERS
83 }
84
85 bool
cpc_is_secure(void)86 cpc_is_secure(void)
87 {
88 #if CONFIG_CPU_COUNTERS
89 #if __arm64__
90 cpc_event_policy_t policy = cpc_get_event_policy();
91 return policy == CPC_EVPOL_RESTRICT_TO_KNOWN || policy == CPC_EVPOL_DENY_ALL;
92 #else // __arm64__
93 return false;
94 #endif // !__arm64__
95 #else // CONFIG_CPU_COUNTERS
96 return true;
97 #endif // !CONFIG_CPU_COUNTERS
98 }
99
100 #if CPC_INSECURE
101
102 void
cpc_change_security(bool enforce_security)103 cpc_change_security(bool enforce_security)
104 {
105 #if CONFIG_CPU_COUNTERS
106 #if __arm64__
107 cpc_set_event_policy(enforce_security ? CPC_EVPOL_RESTRICT_TO_KNOWN : CPC_EVPOL_DEFAULT);
108 extern bool kpc_allows_counting_system;
109 kpc_allows_counting_system = !enforce_security;
110 #else // __arm64__
111 #pragma unused(enforce_security)
112 // Intel has no event policy or other security features.
113 #endif // !__arm64__
114 #else // CONFIG_CPU_COUNTERS
115 #pragma unused(enforce_security)
116 #endif // !CONFIG_CPU_COUNTERS
117 }
118
119 #endif // CPC_INSECURE
120