1 #ifdef CONFIG_CPU_SUP_INTEL
7 LBR_FORMAT_EIP_FLAGS
= 0x03,
11 * We only support LBR implementations that have FREEZE_LBRS_ON_PMI
12 * otherwise it becomes near impossible to get a reliable stack.
15 #define X86_DEBUGCTL_LBR (1 << 0)
16 #define X86_DEBUGCTL_FREEZE_LBRS_ON_PMI (1 << 11)
18 static void __intel_pmu_lbr_enable(void)
22 rdmsrl(MSR_IA32_DEBUGCTLMSR
, debugctl
);
23 debugctl
|= (X86_DEBUGCTL_LBR
| X86_DEBUGCTL_FREEZE_LBRS_ON_PMI
);
24 wrmsrl(MSR_IA32_DEBUGCTLMSR
, debugctl
);
27 static void __intel_pmu_lbr_disable(void)
31 rdmsrl(MSR_IA32_DEBUGCTLMSR
, debugctl
);
32 debugctl
&= ~(X86_DEBUGCTL_LBR
| X86_DEBUGCTL_FREEZE_LBRS_ON_PMI
);
33 wrmsrl(MSR_IA32_DEBUGCTLMSR
, debugctl
);
36 static void intel_pmu_lbr_reset_32(void)
40 for (i
= 0; i
< x86_pmu
.lbr_nr
; i
++)
41 wrmsrl(x86_pmu
.lbr_from
+ i
, 0);
44 static void intel_pmu_lbr_reset_64(void)
48 for (i
= 0; i
< x86_pmu
.lbr_nr
; i
++) {
49 wrmsrl(x86_pmu
.lbr_from
+ i
, 0);
50 wrmsrl(x86_pmu
.lbr_to
+ i
, 0);
54 static void intel_pmu_lbr_reset(void)
59 if (x86_pmu
.intel_cap
.lbr_format
== LBR_FORMAT_32
)
60 intel_pmu_lbr_reset_32();
62 intel_pmu_lbr_reset_64();
65 static void intel_pmu_lbr_enable(struct perf_event
*event
)
67 struct cpu_hw_events
*cpuc
= &__get_cpu_var(cpu_hw_events
);
72 WARN_ON_ONCE(cpuc
->enabled
);
75 * Reset the LBR stack if this is the first LBR user or
76 * we changed task context so as to avoid data leaks.
79 if (!cpuc
->lbr_users
||
80 (event
->ctx
->task
&& cpuc
->lbr_context
!= event
->ctx
)) {
81 intel_pmu_lbr_reset();
82 cpuc
->lbr_context
= event
->ctx
;
88 static void intel_pmu_lbr_disable(struct perf_event
*event
)
90 struct cpu_hw_events
*cpuc
= &__get_cpu_var(cpu_hw_events
);
96 BUG_ON(cpuc
->lbr_users
< 0);
98 if (cpuc
->enabled
&& !cpuc
->lbr_users
)
99 __intel_pmu_lbr_disable();
102 static void intel_pmu_lbr_enable_all(void)
104 struct cpu_hw_events
*cpuc
= &__get_cpu_var(cpu_hw_events
);
107 __intel_pmu_lbr_enable();
110 static void intel_pmu_lbr_disable_all(void)
112 struct cpu_hw_events
*cpuc
= &__get_cpu_var(cpu_hw_events
);
115 __intel_pmu_lbr_disable();
118 static inline u64
intel_pmu_lbr_tos(void)
122 rdmsrl(x86_pmu
.lbr_tos
, tos
);
127 static void intel_pmu_lbr_read_32(struct cpu_hw_events
*cpuc
)
129 unsigned long mask
= x86_pmu
.lbr_nr
- 1;
130 u64 tos
= intel_pmu_lbr_tos();
133 for (i
= 0; i
< x86_pmu
.lbr_nr
; i
++, tos
--) {
134 unsigned long lbr_idx
= (tos
- i
) & mask
;
143 rdmsrl(x86_pmu
.lbr_from
+ lbr_idx
, msr_lastbranch
.lbr
);
145 cpuc
->lbr_entries
[i
].from
= msr_lastbranch
.from
;
146 cpuc
->lbr_entries
[i
].to
= msr_lastbranch
.to
;
147 cpuc
->lbr_entries
[i
].flags
= 0;
149 cpuc
->lbr_stack
.nr
= i
;
152 #define LBR_FROM_FLAG_MISPRED (1ULL << 63)
155 * Due to lack of segmentation in Linux the effective address (offset)
156 * is the same as the linear address, allowing us to merge the LIP and EIP
159 static void intel_pmu_lbr_read_64(struct cpu_hw_events
*cpuc
)
161 unsigned long mask
= x86_pmu
.lbr_nr
- 1;
162 int lbr_format
= x86_pmu
.intel_cap
.lbr_format
;
163 u64 tos
= intel_pmu_lbr_tos();
166 for (i
= 0; i
< x86_pmu
.lbr_nr
; i
++, tos
--) {
167 unsigned long lbr_idx
= (tos
- i
) & mask
;
168 u64 from
, to
, flags
= 0;
170 rdmsrl(x86_pmu
.lbr_from
+ lbr_idx
, from
);
171 rdmsrl(x86_pmu
.lbr_to
+ lbr_idx
, to
);
173 if (lbr_format
== LBR_FORMAT_EIP_FLAGS
) {
174 flags
= !!(from
& LBR_FROM_FLAG_MISPRED
);
175 from
= (u64
)((((s64
)from
) << 1) >> 1);
178 cpuc
->lbr_entries
[i
].from
= from
;
179 cpuc
->lbr_entries
[i
].to
= to
;
180 cpuc
->lbr_entries
[i
].flags
= flags
;
182 cpuc
->lbr_stack
.nr
= i
;
185 static void intel_pmu_lbr_read(void)
187 struct cpu_hw_events
*cpuc
= &__get_cpu_var(cpu_hw_events
);
189 if (!cpuc
->lbr_users
)
192 if (x86_pmu
.intel_cap
.lbr_format
== LBR_FORMAT_32
)
193 intel_pmu_lbr_read_32(cpuc
);
195 intel_pmu_lbr_read_64(cpuc
);
198 static void intel_pmu_lbr_init_core(void)
201 x86_pmu
.lbr_tos
= 0x01c9;
202 x86_pmu
.lbr_from
= 0x40;
203 x86_pmu
.lbr_to
= 0x60;
206 static void intel_pmu_lbr_init_nhm(void)
209 x86_pmu
.lbr_tos
= 0x01c9;
210 x86_pmu
.lbr_from
= 0x680;
211 x86_pmu
.lbr_to
= 0x6c0;
214 static void intel_pmu_lbr_init_atom(void)
217 x86_pmu
.lbr_tos
= 0x01c9;
218 x86_pmu
.lbr_from
= 0x40;
219 x86_pmu
.lbr_to
= 0x60;
222 #endif /* CONFIG_CPU_SUP_INTEL */