powerpc/perf: Trace imc PMU functions

Add PMU functions to support trace-imc.

Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c
index 3cc5e1934f0c9a869b59e62098174f89c4ddebe4..31fa753e2eb2c943a87acd5a498b9a0be369a09e 100644 (file)
--- a/arch/powerpc/perf/imc-pmu.c
+++ b/arch/powerpc/perf/imc-pmu.c
@@ -53,7 +53,7 @@ static struct imc_pmu *imc_event_to_pmu(struct perf_event *event)
        return container_of(event->pmu, struct imc_pmu, pmu);
 }
 
-PMU_FORMAT_ATTR(event, "config:0-40");
+PMU_FORMAT_ATTR(event, "config:0-61");
 PMU_FORMAT_ATTR(offset, "config:0-31");
 PMU_FORMAT_ATTR(rvalue, "config:32");
 PMU_FORMAT_ATTR(mode, "config:33-40");
@@ -70,6 +70,25 @@ static struct attribute_group imc_format_group = {
        .attrs = imc_format_attrs,
 };
 
+/* Format attribute for imc trace-mode */
+PMU_FORMAT_ATTR(cpmc_reserved, "config:0-19");
+PMU_FORMAT_ATTR(cpmc_event, "config:20-27");
+PMU_FORMAT_ATTR(cpmc_samplesel, "config:28-29");
+PMU_FORMAT_ATTR(cpmc_load, "config:30-61");
+static struct attribute *trace_imc_format_attrs[] = {
+       &format_attr_event.attr,
+       &format_attr_cpmc_reserved.attr,
+       &format_attr_cpmc_event.attr,
+       &format_attr_cpmc_samplesel.attr,
+       &format_attr_cpmc_load.attr,
+       NULL,
+};
+
+static struct attribute_group trace_imc_format_group = {
+.name = "format",
+.attrs = trace_imc_format_attrs,
+};
+
 /* Get the cpumask printed to a buffer "buf" */
 static ssize_t imc_pmu_cpumask_get_attr(struct device *dev,
                                        struct device_attribute *attr,
@@ -1113,6 +1132,182 @@ static int trace_imc_cpu_init(void)
                          ppc_trace_imc_cpu_offline);
 }
 
+static u64 get_trace_imc_event_base_addr(void)
+{
+       return (u64)per_cpu(trace_imc_mem, smp_processor_id());
+}
+
+/*
+ * Function to parse trace-imc data obtained
+ * and to prepare the perf sample.
+ */
+static int trace_imc_prepare_sample(struct trace_imc_data *mem,
+                                   struct perf_sample_data *data,
+                                   u64 *prev_tb,
+                                   struct perf_event_header *header,
+                                   struct perf_event *event)
+{
+       /* Sanity checks for a valid record */
+       if (be64_to_cpu(READ_ONCE(mem->tb1)) > *prev_tb)
+               *prev_tb = be64_to_cpu(READ_ONCE(mem->tb1));
+       else
+               return -EINVAL;
+
+       if ((be64_to_cpu(READ_ONCE(mem->tb1)) & IMC_TRACE_RECORD_TB1_MASK) !=
+                        be64_to_cpu(READ_ONCE(mem->tb2)))
+               return -EINVAL;
+
+       /* Prepare perf sample */
+       data->ip =  be64_to_cpu(READ_ONCE(mem->ip));
+       data->period = event->hw.last_period;
+
+       header->type = PERF_RECORD_SAMPLE;
+       header->size = sizeof(*header) + event->header_size;
+       header->misc = 0;
+
+       if (is_kernel_addr(data->ip))
+               header->misc |= PERF_RECORD_MISC_KERNEL;
+       else
+               header->misc |= PERF_RECORD_MISC_USER;
+
+       perf_event_header__init_id(header, data, event);
+
+       return 0;
+}
+
+static void dump_trace_imc_data(struct perf_event *event)
+{
+       struct trace_imc_data *mem;
+       int i, ret;
+       u64 prev_tb = 0;
+
+       mem = (struct trace_imc_data *)get_trace_imc_event_base_addr();
+       for (i = 0; i < (trace_imc_mem_size / sizeof(struct trace_imc_data));
+               i++, mem++) {
+               struct perf_sample_data data;
+               struct perf_event_header header;
+
+               ret = trace_imc_prepare_sample(mem, &data, &prev_tb, &header, event);
+               if (ret) /* Exit, if not a valid record */
+                       break;
+               else {
+                       /* If this is a valid record, create the sample */
+                       struct perf_output_handle handle;
+
+                       if (perf_output_begin(&handle, event, header.size))
+                               return;
+
+                       perf_output_sample(&handle, &header, &data, event);
+                       perf_output_end(&handle);
+               }
+       }
+}
+
+static int trace_imc_event_add(struct perf_event *event, int flags)
+{
+       int core_id = smp_processor_id() / threads_per_core;
+       struct imc_pmu_ref *ref = NULL;
+       u64 local_mem, ldbar_value;
+
+       /* Set trace-imc bit in ldbar and load ldbar with per-thread memory address */
+       local_mem = get_trace_imc_event_base_addr();
+       ldbar_value = ((u64)local_mem & THREAD_IMC_LDBAR_MASK) | TRACE_IMC_ENABLE;
+
+       if (core_imc_refc)
+               ref = &core_imc_refc[core_id];
+       if (!ref) {
+               /* If core-imc is not enabled, use trace-imc reference count */
+               if (trace_imc_refc)
+                       ref = &trace_imc_refc[core_id];
+               if (!ref)
+                       return -EINVAL;
+       }
+       mtspr(SPRN_LDBAR, ldbar_value);
+       mutex_lock(&ref->lock);
+       if (ref->refc == 0) {
+               if (opal_imc_counters_start(OPAL_IMC_COUNTERS_TRACE,
+                               get_hard_smp_processor_id(smp_processor_id()))) {
+                       mutex_unlock(&ref->lock);
+                       pr_err("trace-imc: Unable to start the counters for core %d\n", core_id);
+                       mtspr(SPRN_LDBAR, 0);
+                       return -EINVAL;
+               }
+       }
+       ++ref->refc;
+       mutex_unlock(&ref->lock);
+
+       return 0;
+}
+
+static void trace_imc_event_read(struct perf_event *event)
+{
+       return;
+}
+
+static void trace_imc_event_stop(struct perf_event *event, int flags)
+{
+       u64 local_mem = get_trace_imc_event_base_addr();
+       dump_trace_imc_data(event);
+       memset((void *)local_mem, 0, sizeof(u64));
+}
+
+static void trace_imc_event_start(struct perf_event *event, int flags)
+{
+       return;
+}
+
+static void trace_imc_event_del(struct perf_event *event, int flags)
+{
+       int core_id = smp_processor_id() / threads_per_core;
+       struct imc_pmu_ref *ref = NULL;
+
+       if (core_imc_refc)
+               ref = &core_imc_refc[core_id];
+       if (!ref) {
+               /* If core-imc is not enabled, use trace-imc reference count */
+               if (trace_imc_refc)
+                       ref = &trace_imc_refc[core_id];
+               if (!ref)
+                       return;
+       }
+       mtspr(SPRN_LDBAR, 0);
+       mutex_lock(&ref->lock);
+       ref->refc--;
+       if (ref->refc == 0) {
+               if (opal_imc_counters_stop(OPAL_IMC_COUNTERS_TRACE,
+                               get_hard_smp_processor_id(smp_processor_id()))) {
+                       mutex_unlock(&ref->lock);
+                       pr_err("trace-imc: Unable to stop the counters for core %d\n", core_id);
+                       return;
+               }
+       } else if (ref->refc < 0) {
+               ref->refc = 0;
+       }
+       mutex_unlock(&ref->lock);
+       trace_imc_event_stop(event, flags);
+}
+
+static int trace_imc_event_init(struct perf_event *event)
+{
+       struct task_struct *target;
+
+       if (event->attr.type != event->pmu->type)
+               return -ENOENT;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EACCES;
+
+       /* Return if this is a couting event */
+       if (event->attr.sample_period == 0)
+               return -ENOENT;
+
+       event->hw.idx = -1;
+       target = event->hw.target;
+
+       event->pmu->task_ctx_nr = perf_hw_context;
+       return 0;
+}
+
 /* update_pmu_ops : Populate the appropriate operations for "pmu" */
 static int update_pmu_ops(struct imc_pmu *pmu)
 {
@@ -1143,6 +1338,14 @@ static int update_pmu_ops(struct imc_pmu *pmu)
                pmu->pmu.cancel_txn = thread_imc_pmu_cancel_txn;
                pmu->pmu.commit_txn = thread_imc_pmu_commit_txn;
                break;
+       case IMC_DOMAIN_TRACE:
+               pmu->pmu.event_init = trace_imc_event_init;
+               pmu->pmu.add = trace_imc_event_add;
+               pmu->pmu.del = trace_imc_event_del;
+               pmu->pmu.start = trace_imc_event_start;
+               pmu->pmu.stop = trace_imc_event_stop;
+               pmu->pmu.read = trace_imc_event_read;
+               pmu->attr_groups[IMC_FORMAT_ATTR] = &trace_imc_format_group;
        default:
                break;
        }