powerpc/perf: Trace imc events detection and cpuhotplug

Patch detects trace-imc events, does memory initilizations for each online
cpu, and registers cpuhotplug call-backs.

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 975837d85a80f4fe7de3238d7cecb4d561f31ab5..3cc5e1934f0c9a869b59e62098174f89c4ddebe4 100644 (file)
--- a/arch/powerpc/perf/imc-pmu.c
+++ b/arch/powerpc/perf/imc-pmu.c
@@ -43,6 +43,11 @@ static DEFINE_PER_CPU(u64 *, thread_imc_mem);
 static struct imc_pmu *thread_imc_pmu;
 static int thread_imc_mem_size;
 
+/* Trace IMC data structures */
+static DEFINE_PER_CPU(u64 *, trace_imc_mem);
+static struct imc_pmu_ref *trace_imc_refc;
+static int trace_imc_mem_size;
+
 static struct imc_pmu *imc_event_to_pmu(struct perf_event *event)
 {
        return container_of(event->pmu, struct imc_pmu, pmu);
@@ -1055,6 +1060,59 @@ static void thread_imc_event_del(struct perf_event *event, int flags)
        imc_event_update(event);
 }
 
+/*
+ * Allocate a page of memory for each cpu, and load LDBAR with 0.
+ */
+static int trace_imc_mem_alloc(int cpu_id, int size)
+{
+       u64 *local_mem = per_cpu(trace_imc_mem, cpu_id);
+       int phys_id = cpu_to_node(cpu_id), rc = 0;
+       int core_id = (cpu_id / threads_per_core);
+
+       if (!local_mem) {
+               local_mem = page_address(alloc_pages_node(phys_id,
+                                       GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE |
+                                       __GFP_NOWARN, get_order(size)));
+               if (!local_mem)
+                       return -ENOMEM;
+               per_cpu(trace_imc_mem, cpu_id) = local_mem;
+
+               /* Initialise the counters for trace mode */
+               rc = opal_imc_counters_init(OPAL_IMC_COUNTERS_TRACE, __pa((void *)local_mem),
+                                           get_hard_smp_processor_id(cpu_id));
+               if (rc) {
+                       pr_info("IMC:opal init failed for trace imc\n");
+                       return rc;
+               }
+       }
+
+       /* Init the mutex, if not already */
+       trace_imc_refc[core_id].id = core_id;
+       mutex_init(&trace_imc_refc[core_id].lock);
+
+       mtspr(SPRN_LDBAR, 0);
+       return 0;
+}
+
+static int ppc_trace_imc_cpu_online(unsigned int cpu)
+{
+       return trace_imc_mem_alloc(cpu, trace_imc_mem_size);
+}
+
+static int ppc_trace_imc_cpu_offline(unsigned int cpu)
+{
+       mtspr(SPRN_LDBAR, 0);
+       return 0;
+}
+
+static int trace_imc_cpu_init(void)
+{
+       return cpuhp_setup_state(CPUHP_AP_PERF_POWERPC_TRACE_IMC_ONLINE,
+                         "perf/powerpc/imc_trace:online",
+                         ppc_trace_imc_cpu_online,
+                         ppc_trace_imc_cpu_offline);
+}
+
 /* update_pmu_ops : Populate the appropriate operations for "pmu" */
 static int update_pmu_ops(struct imc_pmu *pmu)
 {
@@ -1177,6 +1235,18 @@ static void cleanup_all_thread_imc_memory(void)
        }
 }
 
+static void cleanup_all_trace_imc_memory(void)
+{
+       int i, order = get_order(trace_imc_mem_size);
+
+       for_each_online_cpu(i) {
+               if (per_cpu(trace_imc_mem, i))
+                       free_pages((u64)per_cpu(trace_imc_mem, i), order);
+
+       }
+       kfree(trace_imc_refc);
+}
+
 /* Function to free the attr_groups which are dynamically allocated */
 static void imc_common_mem_free(struct imc_pmu *pmu_ptr)
 {
@@ -1218,6 +1288,11 @@ static void imc_common_cpuhp_mem_free(struct imc_pmu *pmu_ptr)
                cpuhp_remove_state(CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE);
                cleanup_all_thread_imc_memory();
        }
+
+       if (pmu_ptr->domain == IMC_DOMAIN_TRACE) {
+               cpuhp_remove_state(CPUHP_AP_PERF_POWERPC_TRACE_IMC_ONLINE);
+               cleanup_all_trace_imc_memory();
+       }
 }
 
 /*
@@ -1300,6 +1375,27 @@ static int imc_mem_init(struct imc_pmu *pmu_ptr, struct device_node *parent,
 
                thread_imc_pmu = pmu_ptr;
                break;
+       case IMC_DOMAIN_TRACE:
+               /* Update the pmu name */
+               pmu_ptr->pmu.name = kasprintf(GFP_KERNEL, "%s%s", s, "_imc");
+               if (!pmu_ptr->pmu.name)
+                       return -ENOMEM;
+
+               nr_cores = DIV_ROUND_UP(num_possible_cpus(), threads_per_core);
+               trace_imc_refc = kcalloc(nr_cores, sizeof(struct imc_pmu_ref),
+                                                               GFP_KERNEL);
+               if (!trace_imc_refc)
+                       return -ENOMEM;
+
+               trace_imc_mem_size = pmu_ptr->counter_mem_size;
+               for_each_online_cpu(cpu) {
+                       res = trace_imc_mem_alloc(cpu, trace_imc_mem_size);
+                       if (res) {
+                               cleanup_all_trace_imc_memory();
+                               goto err;
+                       }
+               }
+               break;
        default:
                return -EINVAL;
        }
@@ -1372,6 +1468,14 @@ int init_imc_pmu(struct device_node *parent, struct imc_pmu *pmu_ptr, int pmu_id
                        goto err_free_mem;
                }
 
+               break;
+       case IMC_DOMAIN_TRACE:
+               ret = trace_imc_cpu_init();
+               if (ret) {
+                       cleanup_all_trace_imc_memory();
+                       goto err_free_mem;
+               }
+
                break;
        default:
                return  -EINVAL;        /* Unknown domain */

diff --git a/arch/powerpc/platforms/powernv/opal-imc.c b/arch/powerpc/platforms/powernv/opal-imc.c
index 3d27f02695e41fc5942cf978478d25dcbea46f8b..3e497b91d2100697a890784e774a20504d6c6e1b 100644 (file)
--- a/arch/powerpc/platforms/powernv/opal-imc.c
+++ b/arch/powerpc/platforms/powernv/opal-imc.c
@@ -284,6 +284,9 @@ static int opal_imc_counters_probe(struct platform_device *pdev)
                case IMC_TYPE_THREAD:
                        domain = IMC_DOMAIN_THREAD;
                        break;
+               case IMC_TYPE_TRACE:
+                       domain = IMC_DOMAIN_TRACE;
+                       break;
                default:
                        pr_warn("IMC Unknown Device type \n");
                        domain = -1;

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index e78281d07b70b39ac80de10bf8ef8c6f1cdd3605..c3413d9b8348aec062c44ef821053f125e136ff2 100644 (file)
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -170,6 +170,7 @@ enum cpuhp_state {
        CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE,
        CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE,
        CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
+       CPUHP_AP_PERF_POWERPC_TRACE_IMC_ONLINE,
        CPUHP_AP_WATCHDOG_ONLINE,
        CPUHP_AP_WORKQUEUE_ONLINE,
        CPUHP_AP_RCUTREE_ONLINE,