Merge branch 'linus' into x86/cpu, to pick up fixes
[cascardo/linux.git] / drivers / hwtracing / coresight / coresight.c
index 2ea5961..d08d1ab 100644 (file)
@@ -43,7 +43,15 @@ struct coresight_node {
  * 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 *, sysfs_path);
+static DEFINE_PER_CPU(struct list_head *, tracer_path);
+
+/*
+ * As of this writing only a single STM can be found in CS topologies.  Since
+ * there is no way to know if we'll ever see more and what kind of
+ * configuration they will enact, for the time being only define a single path
+ * for STM.
+ */
+static struct list_head *stm_path;
 
 static int coresight_id_match(struct device *dev, void *data)
 {
@@ -257,15 +265,27 @@ static void coresight_disable_source(struct coresight_device *csdev)
 
 void coresight_disable_path(struct list_head *path)
 {
+       u32 type;
        struct coresight_node *nd;
        struct coresight_device *csdev, *parent, *child;
 
        list_for_each_entry(nd, path, link) {
                csdev = nd->csdev;
+               type = csdev->type;
+
+               /*
+                * ETF devices are tricky... They can be a link or a sink,
+                * depending on how they are configured.  If an ETF has been
+                * "activated" it will be configured as a sink, otherwise
+                * go ahead with the link configuration.
+                */
+               if (type == CORESIGHT_DEV_TYPE_LINKSINK)
+                       type = (csdev == coresight_get_sink(path)) ?
+                                               CORESIGHT_DEV_TYPE_SINK :
+                                               CORESIGHT_DEV_TYPE_LINK;
 
-               switch (csdev->type) {
+               switch (type) {
                case CORESIGHT_DEV_TYPE_SINK:
-               case CORESIGHT_DEV_TYPE_LINKSINK:
                        coresight_disable_sink(csdev);
                        break;
                case CORESIGHT_DEV_TYPE_SOURCE:
@@ -286,15 +306,27 @@ int coresight_enable_path(struct list_head *path, u32 mode)
 {
 
        int ret = 0;
+       u32 type;
        struct coresight_node *nd;
        struct coresight_device *csdev, *parent, *child;
 
        list_for_each_entry_reverse(nd, path, link) {
                csdev = nd->csdev;
+               type = csdev->type;
 
-               switch (csdev->type) {
+               /*
+                * ETF devices are tricky... They can be a link or a sink,
+                * depending on how they are configured.  If an ETF has been
+                * "activated" it will be configured as a sink, otherwise
+                * go ahead with the link configuration.
+                */
+               if (type == CORESIGHT_DEV_TYPE_LINKSINK)
+                       type = (csdev == coresight_get_sink(path)) ?
+                                               CORESIGHT_DEV_TYPE_SINK :
+                                               CORESIGHT_DEV_TYPE_LINK;
+
+               switch (type) {
                case CORESIGHT_DEV_TYPE_SINK:
-               case CORESIGHT_DEV_TYPE_LINKSINK:
                        ret = coresight_enable_sink(csdev, mode);
                        if (ret)
                                goto err;
@@ -353,7 +385,6 @@ static int _coresight_build_path(struct coresight_device *csdev,
        int i;
        bool found = false;
        struct coresight_node *node;
-       struct coresight_connection *conn;
 
        /* An activated sink has been found.  Enqueue the element */
        if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
@@ -362,8 +393,9 @@ static int _coresight_build_path(struct coresight_device *csdev,
 
        /* Not a sink - recursively explore each port found on this element */
        for (i = 0; i < csdev->nr_outport; i++) {
-               conn = &csdev->conns[i];
-               if (_coresight_build_path(conn->child_dev, path) == 0) {
+               struct coresight_device *child_dev = csdev->conns[i].child_dev;
+
+               if (child_dev && _coresight_build_path(child_dev, path) == 0) {
                        found = true;
                        break;
                }
@@ -393,6 +425,7 @@ out:
 struct list_head *coresight_build_path(struct coresight_device *csdev)
 {
        struct list_head *path;
+       int rc;
 
        path = kzalloc(sizeof(struct list_head), GFP_KERNEL);
        if (!path)
@@ -400,9 +433,10 @@ struct list_head *coresight_build_path(struct coresight_device *csdev)
 
        INIT_LIST_HEAD(path);
 
-       if (_coresight_build_path(csdev, path)) {
+       rc = _coresight_build_path(csdev, path);
+       if (rc) {
                kfree(path);
-               path = NULL;
+               return ERR_PTR(rc);
        }
 
        return path;
@@ -432,24 +466,52 @@ void coresight_release_path(struct list_head *path)
        path = NULL;
 }
 
+/** coresight_validate_source - make sure a source has the right credentials
+ *  @csdev:    the device structure for a source.
+ *  @function: the function this was called from.
+ *
+ * Assumes the coresight_mutex is held.
+ */
+static int coresight_validate_source(struct coresight_device *csdev,
+                                    const char *function)
+{
+       u32 type, subtype;
+
+       type = csdev->type;
+       subtype = csdev->subtype.source_subtype;
+
+       if (type != CORESIGHT_DEV_TYPE_SOURCE) {
+               dev_err(&csdev->dev, "wrong device type in %s\n", function);
+               return -EINVAL;
+       }
+
+       if (subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_PROC &&
+           subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE) {
+               dev_err(&csdev->dev, "wrong device subtype in %s\n", function);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
 int coresight_enable(struct coresight_device *csdev)
 {
-       int ret = 0;
-       int cpu;
+       int cpu, ret = 0;
        struct list_head *path;
 
        mutex_lock(&coresight_mutex);
-       if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {
-               ret = -EINVAL;
-               dev_err(&csdev->dev, "wrong device type in %s\n", __func__);
+
+       ret = coresight_validate_source(csdev, __func__);
+       if (ret)
                goto out;
-       }
+
        if (csdev->enable)
                goto out;
 
        path = coresight_build_path(csdev);
-       if (!path) {
+       if (IS_ERR(path)) {
                pr_err("building path(s) failed\n");
+               ret = PTR_ERR(path);
                goto out;
        }
 
@@ -461,15 +523,25 @@ int coresight_enable(struct coresight_device *csdev)
        if (ret)
                goto err_source;
 
-       /*
-        * When working from sysFS it is important to keep track
-        * of the paths that were created so that they can be
-        * undone in 'coresight_disable()'.  Since there can only
-        * be a single session per tracer (when working from sysFS)
-        * a per-cpu variable will do just fine.
-        */
-       cpu = source_ops(csdev)->cpu_id(csdev);
-       per_cpu(sysfs_path, cpu) = path;
+       switch (csdev->subtype.source_subtype) {
+       case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
+               /*
+                * When working from sysFS it is important to keep track
+                * of the paths that were created so that they can be
+                * undone in 'coresight_disable()'.  Since there can only
+                * be a single session per tracer (when working from sysFS)
+                * a per-cpu variable will do just fine.
+                */
+               cpu = source_ops(csdev)->cpu_id(csdev);
+               per_cpu(tracer_path, cpu) = path;
+               break;
+       case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
+               stm_path = path;
+               break;
+       default:
+               /* We can't be here */
+               break;
+       }
 
 out:
        mutex_unlock(&coresight_mutex);
@@ -486,23 +558,36 @@ EXPORT_SYMBOL_GPL(coresight_enable);
 
 void coresight_disable(struct coresight_device *csdev)
 {
-       int cpu;
-       struct list_head *path;
+       int cpu, ret;
+       struct list_head *path = NULL;
 
        mutex_lock(&coresight_mutex);
-       if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {
-               dev_err(&csdev->dev, "wrong device type in %s\n", __func__);
+
+       ret = coresight_validate_source(csdev, __func__);
+       if (ret)
                goto out;
-       }
+
        if (!csdev->enable)
                goto out;
 
-       cpu = source_ops(csdev)->cpu_id(csdev);
-       path = per_cpu(sysfs_path, cpu);
+       switch (csdev->subtype.source_subtype) {
+       case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
+               cpu = source_ops(csdev)->cpu_id(csdev);
+               path = per_cpu(tracer_path, cpu);
+               per_cpu(tracer_path, cpu) = NULL;
+               break;
+       case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
+               path = stm_path;
+               stm_path = NULL;
+               break;
+       default:
+               /* We can't be here */
+               break;
+       }
+
        coresight_disable_source(csdev);
        coresight_disable_path(path);
        coresight_release_path(path);
-       per_cpu(sysfs_path, cpu) = NULL;
 
 out:
        mutex_unlock(&coresight_mutex);
@@ -514,7 +599,7 @@ static ssize_t enable_sink_show(struct device *dev,
 {
        struct coresight_device *csdev = to_coresight_device(dev);
 
-       return scnprintf(buf, PAGE_SIZE, "%u\n", (unsigned)csdev->activated);
+       return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->activated);
 }
 
 static ssize_t enable_sink_store(struct device *dev,
@@ -544,7 +629,7 @@ static ssize_t enable_source_show(struct device *dev,
 {
        struct coresight_device *csdev = to_coresight_device(dev);
 
-       return scnprintf(buf, PAGE_SIZE, "%u\n", (unsigned)csdev->enable);
+       return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->enable);
 }
 
 static ssize_t enable_source_store(struct device *dev,