/* PerfCntrGlobalStatus is read-only */
rdmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_STATUS, status);
- return status & amd_pmu_global_cntr_mask;
+ return status;
}
static inline void amd_pmu_ack_global_status(u64 status)
* clears the same bit in PerfCntrGlobalStatus
*/
- /* Only allow modifications to PerfCntrGlobalStatus.PerfCntrOvfl */
- status &= amd_pmu_global_cntr_mask;
wrmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR, status);
}
__x86_pmu_enable_event(hwc, ARCH_PERFMON_EVENTSEL_ENABLE);
}
-static void amd_pmu_v2_enable_all(int added)
+static __always_inline void amd_pmu_core_enable_all(void)
{
amd_pmu_set_global_ctl(amd_pmu_global_cntr_mask);
}
+static void amd_pmu_v2_enable_all(int added)
+{
+ amd_pmu_lbr_enable_all();
+ amd_pmu_core_enable_all();
+}
+
static void amd_pmu_disable_event(struct perf_event *event)
{
x86_pmu_disable_event(event);
amd_pmu_check_overflow();
}
-static void amd_pmu_v2_disable_all(void)
+static __always_inline void amd_pmu_core_disable_all(void)
{
- /* Disable all PMCs */
amd_pmu_set_global_ctl(0);
+}
+
+static void amd_pmu_v2_disable_all(void)
+{
+ amd_pmu_core_disable_all();
+ amd_pmu_lbr_disable_all();
amd_pmu_check_overflow();
}
pmu_enabled = cpuc->enabled;
cpuc->enabled = 0;
- /* Stop counting */
- amd_pmu_v2_disable_all();
+ /* Stop counting but do not disable LBR */
+ amd_pmu_core_disable_all();
status = amd_pmu_get_global_status();
if (!status)
goto done;
+ /* Read branch records before unfreezing */
+ if (status & GLOBAL_STATUS_LBRS_FROZEN) {
+ amd_pmu_lbr_read();
+ status &= ~GLOBAL_STATUS_LBRS_FROZEN;
+ }
+
for (idx = 0; idx < x86_pmu.num_counters; idx++) {
if (!test_bit(idx, cpuc->active_mask))
continue;
if (!x86_perf_event_set_period(event))
continue;
+ if (has_branch_stack(event))
+ data.br_stack = &cpuc->lbr_stack;
+
if (perf_event_overflow(event, &data, regs))
x86_pmu_stop(event, 0);
*/
WARN_ON(status > 0);
- /* Clear overflow bits */
+ /* Clear overflow and freeze bits */
amd_pmu_ack_global_status(~status);
/*
/* Resume counting only if PMU is active */
if (pmu_enabled)
- amd_pmu_v2_enable_all(0);
+ amd_pmu_core_enable_all();
return amd_pmu_adjust_nmi_window(handled);
}
}
/* LBR and BRS are mutually exclusive features */
- if (amd_pmu_lbr_init() && !amd_brs_init()) {
+ if (!amd_pmu_lbr_init()) {
+ /* LBR requires flushing on context switch */
+ x86_pmu.sched_task = amd_pmu_lbr_sched_task;
+ static_call_update(amd_pmu_branch_hw_config, amd_pmu_lbr_hw_config);
+ static_call_update(amd_pmu_branch_reset, amd_pmu_lbr_reset);
+ static_call_update(amd_pmu_branch_add, amd_pmu_lbr_add);
+ static_call_update(amd_pmu_branch_del, amd_pmu_lbr_del);
+ } else if (!amd_brs_init()) {
/*
* BRS requires special event constraints and flushing on ctxsw.
*/
#include "../perf_event.h"
+struct branch_entry {
+ union {
+ struct {
+ u64 ip:58;
+ u64 ip_sign_ext:5;
+ u64 mispredict:1;
+ } split;
+ u64 full;
+ } from;
+
+ union {
+ struct {
+ u64 ip:58;
+ u64 ip_sign_ext:3;
+ u64 reserved:1;
+ u64 spec:1;
+ u64 valid:1;
+ } split;
+ u64 full;
+ } to;
+};
+
+static __always_inline void amd_pmu_lbr_set_from(unsigned int idx, u64 val)
+{
+ wrmsrl(MSR_AMD_SAMP_BR_FROM + idx * 2, val);
+}
+
+static __always_inline void amd_pmu_lbr_set_to(unsigned int idx, u64 val)
+{
+ wrmsrl(MSR_AMD_SAMP_BR_FROM + idx * 2 + 1, val);
+}
+
+static __always_inline u64 amd_pmu_lbr_get_from(unsigned int idx)
+{
+ u64 val;
+
+ rdmsrl(MSR_AMD_SAMP_BR_FROM + idx * 2, val);
+
+ return val;
+}
+
+static __always_inline u64 amd_pmu_lbr_get_to(unsigned int idx)
+{
+ u64 val;
+
+ rdmsrl(MSR_AMD_SAMP_BR_FROM + idx * 2 + 1, val);
+
+ return val;
+}
+
+static __always_inline u64 sign_ext_branch_ip(u64 ip)
+{
+ u32 shift = 64 - boot_cpu_data.x86_virt_bits;
+
+ return (u64)(((s64)ip << shift) >> shift);
+}
+
+void amd_pmu_lbr_read(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ struct perf_branch_entry *br = cpuc->lbr_entries;
+ struct branch_entry entry;
+ int out = 0, i;
+
+ if (!cpuc->lbr_users)
+ return;
+
+ for (i = 0; i < x86_pmu.lbr_nr; i++) {
+ entry.from.full = amd_pmu_lbr_get_from(i);
+ entry.to.full = amd_pmu_lbr_get_to(i);
+
+ /* Check if a branch has been logged */
+ if (!entry.to.split.valid)
+ continue;
+
+ perf_clear_branch_entry_bitfields(br + out);
+
+ br[out].from = sign_ext_branch_ip(entry.from.split.ip);
+ br[out].to = sign_ext_branch_ip(entry.to.split.ip);
+ br[out].mispred = entry.from.split.mispredict;
+ br[out].predicted = !br[out].mispred;
+ out++;
+ }
+
+ cpuc->lbr_stack.nr = out;
+
+ /*
+ * Internal register renaming always ensures that LBR From[0] and
+ * LBR To[0] always represent the TOS
+ */
+ cpuc->lbr_stack.hw_idx = 0;
+}
+
+static int amd_pmu_lbr_setup_filter(struct perf_event *event)
+{
+ /* No LBR support */
+ if (!x86_pmu.lbr_nr)
+ return -EOPNOTSUPP;
+
+ return 0;
+}
+
+int amd_pmu_lbr_hw_config(struct perf_event *event)
+{
+ int ret = 0;
+
+ /* LBR is not recommended in counting mode */
+ if (!is_sampling_event(event))
+ return -EINVAL;
+
+ ret = amd_pmu_lbr_setup_filter(event);
+ if (!ret)
+ event->attach_state |= PERF_ATTACH_SCHED_CB;
+
+ return ret;
+}
+
+void amd_pmu_lbr_reset(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ int i;
+
+ if (!x86_pmu.lbr_nr)
+ return;
+
+ /* Reset all branch records individually */
+ for (i = 0; i < x86_pmu.lbr_nr; i++) {
+ amd_pmu_lbr_set_from(i, 0);
+ amd_pmu_lbr_set_to(i, 0);
+ }
+
+ cpuc->last_task_ctx = NULL;
+ cpuc->last_log_id = 0;
+}
+
+void amd_pmu_lbr_add(struct perf_event *event)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ if (!x86_pmu.lbr_nr)
+ return;
+
+ perf_sched_cb_inc(event->ctx->pmu);
+
+ if (!cpuc->lbr_users++ && !event->total_time_running)
+ amd_pmu_lbr_reset();
+}
+
+void amd_pmu_lbr_del(struct perf_event *event)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ if (!x86_pmu.lbr_nr)
+ return;
+
+ cpuc->lbr_users--;
+ WARN_ON_ONCE(cpuc->lbr_users < 0);
+ perf_sched_cb_dec(event->ctx->pmu);
+}
+
+void amd_pmu_lbr_sched_task(struct perf_event_context *ctx, bool sched_in)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ /*
+ * A context switch can flip the address space and LBR entries are
+ * not tagged with an identifier. Hence, branches cannot be resolved
+ * from the old address space and the LBR records should be wiped.
+ */
+ if (cpuc->lbr_users && sched_in)
+ amd_pmu_lbr_reset();
+}
+
+void amd_pmu_lbr_enable_all(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ u64 dbg_ctl, dbg_extn_cfg;
+
+ if (!cpuc->lbr_users || !x86_pmu.lbr_nr)
+ return;
+
+ rdmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl);
+ rdmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg);
+
+ wrmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI);
+ wrmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg | DBG_EXTN_CFG_LBRV2EN);
+}
+
+void amd_pmu_lbr_disable_all(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ u64 dbg_ctl, dbg_extn_cfg;
+
+ if (!cpuc->lbr_users || !x86_pmu.lbr_nr)
+ return;
+
+ rdmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg);
+ rdmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl);
+
+ wrmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg & ~DBG_EXTN_CFG_LBRV2EN);
+ wrmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl & ~DEBUGCTLMSR_FREEZE_LBRS_ON_PMI);
+}
+
__init int amd_pmu_lbr_init(void)
{
union cpuid_0x80000022_ebx ebx;
projects / kernel.git / commitdiff