#include <linux/mm.h>
#include <linux/init.h>
#include <linux/perf_event.h>
+#include <linux/percpu-defs.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/workqueue.h>
static struct pmu etm_pmu;
static bool etm_perf_up;
-/**
- * struct etm_event_data - Coresight specifics associated to an event
- * @work: Handle to free allocated memory outside IRQ context.
- * @mask: Hold the CPU(s) this event was set for.
- * @snk_config: The sink configuration.
- * @path: An array of path, each slot for one CPU.
- */
-struct etm_event_data {
- struct work_struct work;
- cpumask_t mask;
- void *snk_config;
- struct list_head **path;
-};
-
static DEFINE_PER_CPU(struct perf_output_handle, ctx_handle);
static DEFINE_PER_CPU(struct coresight_device *, csdev_src);
NULL,
};
+static inline struct list_head **
+etm_event_cpu_path_ptr(struct etm_event_data *data, int cpu)
+{
+ return per_cpu_ptr(data->path, cpu);
+}
+
+static inline struct list_head *
+etm_event_cpu_path(struct etm_event_data *data, int cpu)
+{
+ return *etm_event_cpu_path_ptr(data, cpu);
+}
+
static void etm_event_read(struct perf_event *event) {}
static int etm_addr_filters_alloc(struct perf_event *event)
event_data = container_of(work, struct etm_event_data, work);
mask = &event_data->mask;
- /*
- * First deal with the sink configuration. See comment in
- * etm_setup_aux() about why we take the first available path.
- */
- if (event_data->snk_config) {
+
+ /* Free the sink buffers, if there are any */
+ if (event_data->snk_config && !WARN_ON(cpumask_empty(mask))) {
cpu = cpumask_first(mask);
- sink = coresight_get_sink(event_data->path[cpu]);
+ sink = coresight_get_sink(etm_event_cpu_path(event_data, cpu));
if (sink_ops(sink)->free_buffer)
sink_ops(sink)->free_buffer(event_data->snk_config);
}
for_each_cpu(cpu, mask) {
- if (!(IS_ERR_OR_NULL(event_data->path[cpu])))
- coresight_release_path(event_data->path[cpu]);
+ struct list_head **ppath;
+
+ ppath = etm_event_cpu_path_ptr(event_data, cpu);
+ if (!(IS_ERR_OR_NULL(*ppath)))
+ coresight_release_path(*ppath);
+ *ppath = NULL;
}
- kfree(event_data->path);
+ free_percpu(event_data->path);
kfree(event_data);
}
static void *alloc_event_data(int cpu)
{
- int size;
cpumask_t *mask;
struct etm_event_data *event_data;
if (!event_data)
return NULL;
- /* Make sure nothing disappears under us */
- get_online_cpus();
- size = num_online_cpus();
mask = &event_data->mask;
if (cpu != -1)
cpumask_set_cpu(cpu, mask);
else
- cpumask_copy(mask, cpu_online_mask);
- put_online_cpus();
+ cpumask_copy(mask, cpu_present_mask);
/*
* Each CPU has a single path between source and destination. As such
* unused memory when dealing with single CPU trace scenarios is small
* compared to the cost of searching through an optimized array.
*/
- event_data->path = kcalloc(size,
- sizeof(struct list_head *), GFP_KERNEL);
+ event_data->path = alloc_percpu(struct list_head *);
+
if (!event_data->path) {
kfree(event_data);
return NULL;
* on the cmd line. As such the "enable_sink" flag in sysFS is reset.
*/
sink = coresight_get_enabled_sink(true);
- if (!sink)
+ if (!sink || !sink_ops(sink)->alloc_buffer)
goto err;
mask = &event_data->mask;
- /* Setup the path for each CPU in a trace session */
+ /*
+ * Setup the path for each CPU in a trace session. We try to build
+ * trace path for each CPU in the mask. If we don't find an ETM
+ * for the CPU or fail to build a path, we clear the CPU from the
+ * mask and continue with the rest. If ever we try to trace on those
+ * CPUs, we can handle it and fail the session.
+ */
for_each_cpu(cpu, mask) {
+ struct list_head *path;
struct coresight_device *csdev;
csdev = per_cpu(csdev_src, cpu);
- if (!csdev)
- goto err;
+ /*
+ * If there is no ETM associated with this CPU clear it from
+ * the mask and continue with the rest. If ever we try to trace
+ * on this CPU, we handle it accordingly.
+ */
+ if (!csdev) {
+ cpumask_clear_cpu(cpu, mask);
+ continue;
+ }
/*
* Building a path doesn't enable it, it simply builds a
* list of devices from source to sink that can be
* referenced later when the path is actually needed.
*/
- event_data->path[cpu] = coresight_build_path(csdev, sink);
- if (IS_ERR(event_data->path[cpu]))
- goto err;
+ path = coresight_build_path(csdev, sink);
+ if (IS_ERR(path)) {
+ cpumask_clear_cpu(cpu, mask);
+ continue;
+ }
+
+ *etm_event_cpu_path_ptr(event_data, cpu) = path;
}
- if (!sink_ops(sink)->alloc_buffer)
+ /* If we don't have any CPUs ready for tracing, abort */
+ cpu = cpumask_first(mask);
+ if (cpu >= nr_cpu_ids)
goto err;
- cpu = cpumask_first(mask);
- /* Get the AUX specific data from the sink buffer */
+ /* Allocate the sink buffer for this session */
event_data->snk_config =
sink_ops(sink)->alloc_buffer(sink, cpu, pages,
nr_pages, overwrite);
struct etm_event_data *event_data;
struct perf_output_handle *handle = this_cpu_ptr(&ctx_handle);
struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);
+ struct list_head *path;
if (!csdev)
goto fail;
if (!event_data)
goto fail;
+ path = etm_event_cpu_path(event_data, cpu);
/* We need a sink, no need to continue without one */
- sink = coresight_get_sink(event_data->path[cpu]);
+ sink = coresight_get_sink(path);
if (WARN_ON_ONCE(!sink || !sink_ops(sink)->set_buffer))
goto fail_end_stop;
goto fail_end_stop;
/* Nothing will happen without a path */
- if (coresight_enable_path(event_data->path[cpu], CS_MODE_PERF))
+ if (coresight_enable_path(path, CS_MODE_PERF))
goto fail_end_stop;
/* Tell the perf core the event is alive */
/* Finally enable the tracer */
if (source_ops(csdev)->enable(csdev, event, CS_MODE_PERF))
- goto fail_end_stop;
+ goto fail_disable_path;
out:
return;
+fail_disable_path:
+ coresight_disable_path(path);
fail_end_stop:
perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
perf_aux_output_end(handle, 0);
struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);
struct perf_output_handle *handle = this_cpu_ptr(&ctx_handle);
struct etm_event_data *event_data = perf_get_aux(handle);
+ struct list_head *path;
if (event->hw.state == PERF_HES_STOPPED)
return;
if (!csdev)
return;
- sink = coresight_get_sink(event_data->path[cpu]);
+ path = etm_event_cpu_path(event_data, cpu);
+ if (!path)
+ return;
+
+ sink = coresight_get_sink(path);
if (!sink)
return;
if (!sink_ops(sink)->update_buffer)
return;
- sink_ops(sink)->update_buffer(sink, handle,
+ size = sink_ops(sink)->update_buffer(sink, handle,
event_data->snk_config);
-
- if (!sink_ops(sink)->reset_buffer)
- return;
-
- size = sink_ops(sink)->reset_buffer(sink, handle,
- event_data->snk_config);
-
perf_aux_output_end(handle, size);
}
/* Disabling the path make its elements available to other sessions */
- coresight_disable_path(event_data->path[cpu]);
+ coresight_disable_path(path);
}
static int etm_event_add(struct perf_event *event, int mode)
projects / linux-2.6-microblaze.git / blobdiff