[PATCH] remoteproc: Add support for predefined notifyids

[Clement Leger <cleger@xxxxxxxxx>]

In order to support preallocated notify ids, if their value is
equal to FW_RSC_NOTIFY_ID_ANY, then do no allocate a notify id
dynamically but try to allocate the requested one. This is useful when
using custom ids to bind them to custom vendor resources. For instance,
it allow to assign a group of queues to a specific interrupti in order
to dispatch notifications.

Signed-off-by: Clement Leger <cleger@xxxxxxxxx>
---
 drivers/remoteproc/remoteproc_core.c | 27 +++++++++++++++++++--------
 include/linux/remoteproc.h           |  1 +
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 307df98347ba..b1485fcd0f11 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -351,14 +351,27 @@ int rproc_alloc_vring(struct rproc_vdev *rvdev, int i)
 	/*
 	 * Assign an rproc-wide unique index for this vring
 	 * TODO: assign a notifyid for rvdev updates as well
-	 * TODO: support predefined notifyids (via resource table)
 	 */
-	ret = idr_alloc(&rproc->notifyids, rvring, 0, 0, GFP_KERNEL);
-	if (ret < 0) {
-		dev_err(dev, "idr_alloc failed: %d\n", ret);
-		return ret;
+	if (rsc->vring[i].notifyid == FW_RSC_NOTIFY_ID_ANY) {
+		ret = idr_alloc(&rproc->notifyids, rvring, 0, 0, GFP_KERNEL);
+		if (ret < 0) {
+			dev_err(dev, "idr_alloc failed: %d\n", ret);
+			return ret;
+		}
+		notifyid = ret;
+
+		/* Let the rproc know the notifyid of this vring.*/
+		rsc->vring[i].notifyid = notifyid;
+	} else {
+		/* Reserve requested notify_id */
+		notifyid = rsc->vring[i].notifyid;
+		ret = idr_alloc(&rproc->notifyids, rvring, notifyid,
+				notifyid + 1, GFP_KERNEL);
+		if (ret < 0) {
+			dev_err(dev, "idr_alloc failed: %d\n", ret);
+			return ret;
+		}
 	}
-	notifyid = ret;
 
 	/* Potentially bump max_notifyid */
 	if (notifyid > rproc->max_notifyid)
@@ -366,8 +379,6 @@ int rproc_alloc_vring(struct rproc_vdev *rvdev, int i)
 
 	rvring->notifyid = notifyid;
 
-	/* Let the rproc know the notifyid of this vring.*/
-	rsc->vring[i].notifyid = notifyid;
 	return 0;
 }
 
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 16ad66683ad0..dcae3394243e 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -123,6 +123,7 @@ enum fw_resource_type {
 };
 
 #define FW_RSC_ADDR_ANY (-1)
+#define FW_RSC_NOTIFY_ID_ANY (-1)
 
 /**
  * struct fw_rsc_carveout - physically contiguous memory request
-- 
2.15.0.276.g89ea799