interconnect: Allow inter-provider pairs to be configured

This patch adds support for a new boolean 'inter_set' field in struct
icc_provider. Setting it to 'true' enables calling '->set' for
inter-provider node pairs. All existing users of the interconnect
framework allocate this structure with kzalloc, and are therefore
unaffected by this change.

This makes it easier for hierarchies like exynos-bus, where every bus
is probed separately and registers a separate interconnect provider, to
model constraints between buses.

Signed-off-by: Artur Świgoń <a.swigon@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200521122841.8867-4-s.nawrocki@samsung.com
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 8b4d50d59e16dc0d3af8c142827c1cc942ccbeb1..609e206bf598e2d85d6c30d2fc6005dc0e839b19 100644 (file)
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -263,23 +263,22 @@ static int aggregate_requests(struct icc_node *node)
 static int apply_constraints(struct icc_path *path)
 {
        struct icc_node *next, *prev = NULL;
+       struct icc_provider *p;
        int ret = -EINVAL;
        int i;
 
        for (i = 0; i < path->num_nodes; i++) {
                next = path->reqs[i].node;
+               p = next->provider;
 
-               /*
-                * Both endpoints should be valid master-slave pairs of the
-                * same interconnect provider that will be configured.
-                */
-               if (!prev || next->provider != prev->provider) {
+               /* both endpoints should be valid master-slave pairs */
+               if (!prev || (p != prev->provider && !p->inter_set)) {
                        prev = next;
                        continue;
                }
 
                /* set the constraints */
-               ret = next->provider->set(prev, next);
+               ret = p->set(prev, next);
                if (ret)
                        goto out;
 

diff --git a/include/linux/interconnect-provider.h b/include/linux/interconnect-provider.h
index c92be2a90fa0b484102468a56f137111b5b814fe..38701925ab91ea54ee88a478a1865b1adb2795e7 100644 (file)
--- a/include/linux/interconnect-provider.h
+++ b/include/linux/interconnect-provider.h
@@ -41,6 +41,7 @@ struct icc_node *of_icc_xlate_onecell(struct of_phandle_args *spec,
  * @xlate: provider-specific callback for mapping nodes from phandle arguments
  * @dev: the device this interconnect provider belongs to
  * @users: count of active users
+ * @inter_set: whether inter-provider pairs will be configured with @set
  * @data: pointer to private data
  */
 struct icc_provider {
@@ -53,6 +54,7 @@ struct icc_provider {
        struct icc_node* (*xlate)(struct of_phandle_args *spec, void *data);
        struct device           *dev;
        int                     users;
+       bool                    inter_set;
        void                    *data;
 };