interconnect: Add support for path tags

Consumers may have use cases with different bandwidth requirements based
on the system or driver state. The consumer driver can append a specific
tag to the path and pass this information to the interconnect platform
driver to do the aggregation based on this state.

Introduce icc_set_tag() function that will allow the consumers to append
an optional tag to each path. The aggregation of these tagged paths is
platform specific.

Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

4 files changed, 31 insertions, 4 deletions

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 871eb4bc4efc..251354bb7fdc 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -29,6 +29,7 @@ static struct dentry *icc_debugfs_dir;
  * @req_node: entry in list of requests for the particular @node
  * @node: the interconnect node to which this constraint applies
  * @dev: reference to the device that sets the constraints
+ * @tag: path tag (optional)
  * @avg_bw: an integer describing the average bandwidth in kBps
  * @peak_bw: an integer describing the peak bandwidth in kBps
  */
@@ -36,6 +37,7 @@ struct icc_req {
         struct hlist_node req_node;
         struct icc_node *node;
         struct device *dev;
+        u32 tag;
         u32 avg_bw;
         u32 peak_bw;
 };
@@ -204,7 +206,7 @@ static int aggregate_requests(struct icc_node *node)
         node->peak_bw = 0;
 
         hlist_for_each_entry(r, &node->req_list, req_node)
-                p->aggregate(node, r->avg_bw, r->peak_bw,
+                p->aggregate(node, r->tag, r->avg_bw, r->peak_bw,
                              &node->avg_bw, &node->peak_bw);
 
         return 0;
@@ -386,6 +388,26 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
 EXPORT_SYMBOL_GPL(of_icc_get);
 
 /**
+ * icc_set_tag() - set an optional tag on a path
+ * @path: the path we want to tag
+ * @tag: the tag value
+ *
+ * This function allows consumers to append a tag to the requests associated
+ * with a path, so that a different aggregation could be done based on this tag.
+ */
+void icc_set_tag(struct icc_path *path, u32 tag)
+{
+        int i;
+
+        if (!path)
+                return;
+
+        for (i = 0; i < path->num_nodes; i++)
+                path->reqs[i].tag = tag;
+}
+EXPORT_SYMBOL_GPL(icc_set_tag);
+
+/**
  * icc_set_bw() - set bandwidth constraints on an interconnect path
  * @path: reference to the path returned by icc_get()
  * @avg_bw: average bandwidth in kilobytes per second
diff --git a/drivers/interconnect/qcom/sdm845.c b/drivers/interconnect/qcom/sdm845.c
index 4915b78da673..fb526004c82e 100644
--- a/drivers/interconnect/qcom/sdm845.c
+++ b/drivers/interconnect/qcom/sdm845.c
@@ -626,7 +626,7 @@ static void bcm_aggregate(struct qcom_icc_bcm *bcm)
         bcm->dirty = false;
 }
 
-static int qcom_icc_aggregate(struct icc_node *node, u32 avg_bw,
+static int qcom_icc_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
                               u32 peak_bw, u32 *agg_avg, u32 *agg_peak)
 {
         size_t i;
diff --git a/include/linux/interconnect-provider.h b/include/linux/interconnect-provider.h
index 63caccadc2db..4ee19fd41568 100644
--- a/include/linux/interconnect-provider.h
+++ b/include/linux/interconnect-provider.h
@@ -45,8 +45,8 @@ struct icc_provider {
         struct list_head        provider_list;
         struct list_head        nodes;
         int (*set)(struct icc_node *src, struct icc_node *dst);
-        int (*aggregate)(struct icc_node *node, u32 avg_bw, u32 peak_bw,
-                         u32 *agg_avg, u32 *agg_peak);
+        int (*aggregate)(struct icc_node *node, u32 tag, u32 avg_bw,
+                         u32 peak_bw, u32 *agg_avg, u32 *agg_peak);
         struct icc_node* (*xlate)(struct of_phandle_args *spec, void *data);
         struct device           *dev;
         int                     users;
diff --git a/include/linux/interconnect.h b/include/linux/interconnect.h
index dc25864755ba..d70a914cba11 100644
--- a/include/linux/interconnect.h
+++ b/include/linux/interconnect.h
@@ -30,6 +30,7 @@ struct icc_path *icc_get(struct device *dev, const int src_id,
 struct icc_path *of_icc_get(struct device *dev, const char *name);
 void icc_put(struct icc_path *path);
 int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw);
+void icc_set_tag(struct icc_path *path, u32 tag);
 
 #else
 
@@ -54,6 +55,10 @@ static inline int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
         return 0;
 }
 
+static inline void icc_set_tag(struct icc_path *path, u32 tag)
+{
+}
+
 #endif /* CONFIG_INTERCONNECT */
 
 #endif /* __LINUX_INTERCONNECT_H */