Coresight: Introduce a new struct coresight_path

Introduce a new strcuture, 'struct coresight_path', to store the data that
utilized by the devices in the path. The coresight_path will be built/released
by coresight_build_path/coresight_release_path functions.

Signed-off-by: Jie Gan <quic_jiegan@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250303032931.2500935-5-quic_jiegan@quicinc.com

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 44ad407817c140b660784d7b705fb8cf586071d4..b34b5e4776c4db424d3a3bf2404cfda6b0d2f219 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -670,7 +670,7 @@ static void coresight_drop_device(struct coresight_device *csdev)
 static int _coresight_build_path(struct coresight_device *csdev,
                                 struct coresight_device *source,
                                 struct coresight_device *sink,
-                                struct list_head *path)
+                                struct coresight_path *path)
 {
        int i, ret;
        bool found = false;
@@ -723,25 +723,25 @@ out:
                return -ENOMEM;
 
        node->csdev = csdev;
-       list_add(&node->link, path);
+       list_add(&node->link, &path->path_list);
 
        return 0;
 }
 
-struct list_head *coresight_build_path(struct coresight_device *source,
+struct coresight_path *coresight_build_path(struct coresight_device *source,
                                       struct coresight_device *sink)
 {
-       struct list_head *path;
+       struct coresight_path *path;
        int rc;
 
        if (!sink)
                return ERR_PTR(-EINVAL);
 
-       path = kzalloc(sizeof(struct list_head), GFP_KERNEL);
+       path = kzalloc(sizeof(struct coresight_path), GFP_KERNEL);
        if (!path)
                return ERR_PTR(-ENOMEM);
 
-       INIT_LIST_HEAD(path);
+       INIT_LIST_HEAD(&path->path_list);
 
        rc = _coresight_build_path(source, source, sink, path);
        if (rc) {
@@ -759,12 +759,12 @@ struct list_head *coresight_build_path(struct coresight_device *source,
  * Go through all the elements of a path and 1) removed it from the list and
  * 2) free the memory allocated for each node.
  */
-void coresight_release_path(struct list_head *path)
+void coresight_release_path(struct coresight_path *path)
 {
        struct coresight_device *csdev;
        struct coresight_node *nd, *next;
 
-       list_for_each_entry_safe(nd, next, path, link) {
+       list_for_each_entry_safe(nd, next, &path->path_list, link) {
                csdev = nd->csdev;
 
                coresight_drop_device(csdev);

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index ad6a8f4b70b6fc37d9340bcdd4e0569a38fe1c36..b0426792f08a4f0a29e43c3d203cd227352b9dc3 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -136,13 +136,13 @@ static const struct attribute_group *etm_pmu_attr_groups[] = {
        NULL,
 };
 
-static inline struct list_head **
+static inline struct coresight_path **
 etm_event_cpu_path_ptr(struct etm_event_data *data, int cpu)
 {
        return per_cpu_ptr(data->path, cpu);
 }
 
-static inline struct list_head *
+static inline struct coresight_path *
 etm_event_cpu_path(struct etm_event_data *data, int cpu)
 {
        return *etm_event_cpu_path_ptr(data, cpu);
@@ -197,6 +197,7 @@ static void free_sink_buffer(struct etm_event_data *event_data)
        int cpu;
        cpumask_t *mask = &event_data->mask;
        struct coresight_device *sink;
+       struct coresight_path *path;
 
        if (!event_data->snk_config)
                return;
@@ -205,7 +206,8 @@ static void free_sink_buffer(struct etm_event_data *event_data)
                return;
 
        cpu = cpumask_first(mask);
-       sink = coresight_get_sink(etm_event_cpu_path(event_data, cpu));
+       path = etm_event_cpu_path(event_data, cpu);
+       sink = coresight_get_sink(&path->path_list);
        sink_ops(sink)->free_buffer(event_data->snk_config);
 }
 
@@ -226,11 +228,11 @@ static void free_event_data(struct work_struct *work)
                cscfg_deactivate_config(event_data->cfg_hash);
 
        for_each_cpu(cpu, mask) {
-               struct list_head **ppath;
+               struct coresight_path **ppath;
 
                ppath = etm_event_cpu_path_ptr(event_data, cpu);
                if (!(IS_ERR_OR_NULL(*ppath))) {
-                       struct coresight_device *sink = coresight_get_sink(*ppath);
+                       struct coresight_device *sink = coresight_get_sink(&((*ppath)->path_list));
 
                        /*
                         * Mark perf event as done for trace id allocator, but don't call
@@ -276,7 +278,7 @@ static void *alloc_event_data(int cpu)
         * unused memory when dealing with single CPU trace scenarios is small
         * compared to the cost of searching through an optimized array.
         */
-       event_data->path = alloc_percpu(struct list_head *);
+       event_data->path = alloc_percpu(struct coresight_path *);
 
        if (!event_data->path) {
                kfree(event_data);
@@ -352,7 +354,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
         * CPUs, we can handle it and fail the session.
         */
        for_each_cpu(cpu, mask) {
-               struct list_head *path;
+               struct coresight_path *path;
                struct coresight_device *csdev;
 
                csdev = per_cpu(csdev_src, cpu);
@@ -458,7 +460,7 @@ static void etm_event_start(struct perf_event *event, int flags)
        struct etm_ctxt *ctxt = this_cpu_ptr(&etm_ctxt);
        struct perf_output_handle *handle = &ctxt->handle;
        struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);
-       struct list_head *path;
+       struct coresight_path *path;
        u64 hw_id;
        u8 trace_id;
 
@@ -494,12 +496,12 @@ static void etm_event_start(struct perf_event *event, int flags)
 
        path = etm_event_cpu_path(event_data, cpu);
        /* We need a sink, no need to continue without one */
-       sink = coresight_get_sink(path);
+       sink = coresight_get_sink(&path->path_list);
        if (WARN_ON_ONCE(!sink))
                goto fail_end_stop;
 
        /* Nothing will happen without a path */
-       if (coresight_enable_path(path, CS_MODE_PERF, handle))
+       if (coresight_enable_path(&path->path_list, CS_MODE_PERF, handle))
                goto fail_end_stop;
 
        /* Finally enable the tracer */
@@ -534,7 +536,7 @@ out:
        return;
 
 fail_disable_path:
-       coresight_disable_path(path);
+       coresight_disable_path(&path->path_list);
 fail_end_stop:
        /*
         * Check if the handle is still associated with the event,
@@ -558,7 +560,7 @@ static void etm_event_stop(struct perf_event *event, int mode)
        struct etm_ctxt *ctxt = this_cpu_ptr(&etm_ctxt);
        struct perf_output_handle *handle = &ctxt->handle;
        struct etm_event_data *event_data;
-       struct list_head *path;
+       struct coresight_path *path;
 
        /*
         * If we still have access to the event_data via handle,
@@ -599,7 +601,7 @@ static void etm_event_stop(struct perf_event *event, int mode)
        if (!path)
                return;
 
-       sink = coresight_get_sink(path);
+       sink = coresight_get_sink(&path->path_list);
        if (!sink)
                return;
 
@@ -643,7 +645,7 @@ static void etm_event_stop(struct perf_event *event, int mode)
        }
 
        /* Disabling the path make its elements available to other sessions */
-       coresight_disable_path(path);
+       coresight_disable_path(&path->path_list);
 }
 
 static int etm_event_add(struct perf_event *event, int mode)

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.h b/drivers/hwtracing/coresight/coresight-etm-perf.h
index 744531158d6ba4d75ca82a30c98bdb9db0331e34..5febbcdb8696b0c0b937e681ff007cfff6814f6a 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-etm-perf.h
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.h
@@ -59,7 +59,7 @@ struct etm_event_data {
        cpumask_t aux_hwid_done;
        void *snk_config;
        u32 cfg_hash;
-       struct list_head * __percpu *path;
+       struct coresight_path * __percpu *path;
 };
 
 int etm_perf_symlink(struct coresight_device *csdev, bool link);

diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index 76403530f33e0c50184cede7aaf1929471890188..27b7dc348d4af56f3d9a4d2bc0382748b96a9d8d 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -139,9 +139,9 @@ struct coresight_device *coresight_get_sink(struct list_head *path);
 struct coresight_device *coresight_get_sink_by_id(u32 id);
 struct coresight_device *
 coresight_find_default_sink(struct coresight_device *csdev);
-struct list_head *coresight_build_path(struct coresight_device *csdev,
-                                      struct coresight_device *sink);
-void coresight_release_path(struct list_head *path);
+struct coresight_path *coresight_build_path(struct coresight_device *csdev,
+                                           struct coresight_device *sink);
+void coresight_release_path(struct coresight_path *path);
 int coresight_add_sysfs_link(struct coresight_sysfs_link *info);
 void coresight_remove_sysfs_link(struct coresight_sysfs_link *info);
 int coresight_create_conns_sysfs_group(struct coresight_device *csdev);

diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c
index a01c9e54e2edbbcab6cdf5c3cde1d0247aad0836..cb4c39732d26fdd414783ba359588f62955dec54 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-sysfs.c
@@ -22,7 +22,7 @@ static DEFINE_IDR(path_idr);
  * When operating Coresight drivers from the sysFS interface, only a single
  * path can exist from a tracer (associated to a CPU) to a sink.
  */
-static DEFINE_PER_CPU(struct list_head *, tracer_path);
+static DEFINE_PER_CPU(struct coresight_path *, tracer_path);
 
 ssize_t coresight_simple_show_pair(struct device *_dev,
                              struct device_attribute *attr, char *buf)
@@ -167,7 +167,7 @@ int coresight_enable_sysfs(struct coresight_device *csdev)
 {
        int cpu, ret = 0;
        struct coresight_device *sink;
-       struct list_head *path;
+       struct coresight_path *path;
        enum coresight_dev_subtype_source subtype;
        u32 hash;
 
@@ -209,7 +209,7 @@ int coresight_enable_sysfs(struct coresight_device *csdev)
                goto out;
        }
 
-       ret = coresight_enable_path(path, CS_MODE_SYSFS, NULL);
+       ret = coresight_enable_path(&path->path_list, CS_MODE_SYSFS, NULL);
        if (ret)
                goto err_path;
 
@@ -251,7 +251,7 @@ out:
        return ret;
 
 err_source:
-       coresight_disable_path(path);
+       coresight_disable_path(&path->path_list);
 
 err_path:
        coresight_release_path(path);
@@ -262,7 +262,7 @@ EXPORT_SYMBOL_GPL(coresight_enable_sysfs);
 void coresight_disable_sysfs(struct coresight_device *csdev)
 {
        int cpu, ret;
-       struct list_head *path = NULL;
+       struct coresight_path *path = NULL;
        u32 hash;
 
        mutex_lock(&coresight_mutex);
@@ -297,7 +297,7 @@ void coresight_disable_sysfs(struct coresight_device *csdev)
                break;
        }
 
-       coresight_disable_path(path);
+       coresight_disable_path(&path->path_list);
        coresight_release_path(path);
 
 out:

diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 1396bda77f3fa9c4afed2f5f77b141f135d96c4f..509e1f256412fc42c732b80f784374200771c78c 100644 (file)
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -329,6 +329,16 @@ static struct coresight_dev_list (var) = {                         \
 
 #define to_coresight_device(d) container_of(d, struct coresight_device, dev)
 
+/**
+ * struct coresight_path - data needed by enable/disable path
+ * @path_list:              path from source to sink.
+ * @trace_id:          trace_id of the whole path.
+ */
+struct coresight_path {
+       struct list_head        path_list;
+       u8                      trace_id;
+};
+
 enum cs_mode {
        CS_MODE_DISABLED,
        CS_MODE_SYSFS,