From: Matthew Wilcox <willy@infradead.org>
Date: Mon, 18 Feb 2019 21:56:39 +0000 (-0500)
Subject: rpmsg: Convert endpoints to XArray
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f38c34301fce4e0a0145a49b236262a6695d9b54;p=users%2Fwilly%2Fxarray.git

rpmsg: Convert endpoints to XArray

Signed-off-by: Matthew Wilcox <willy@infradead.org>
---

diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
index 5d3685bd76a2..9e6994f61669 100644
--- a/drivers/rpmsg/virtio_rpmsg_bus.c
+++ b/drivers/rpmsg/virtio_rpmsg_bus.c
@@ -43,8 +43,7 @@
  * @tx_lock:	protects svq, sbufs and sleepers, to allow concurrent senders.
  *		sending a message might require waking up a dozing remote
  *		processor, which involves sleeping, hence the mutex.
- * @endpoints:	idr of local endpoints, allows fast retrieval
- * @endpoints_lock: lock of the endpoints set
+ * @endpoints:	local endpoints, allows fast retrieval
  * @sendq:	wait queue of sending contexts waiting for a tx buffers
  * @sleepers:	number of senders that are waiting for a tx buffer
  * @ns_ept:	the bus's name service endpoint
@@ -62,8 +61,7 @@ struct virtproc_info {
 	int last_sbuf;
 	dma_addr_t bufs_dma;
 	struct mutex tx_lock;
-	struct idr endpoints;
-	struct mutex endpoints_lock;
+	struct xarray endpoints;
 	wait_queue_head_t sendq;
 	atomic_t sleepers;
 	struct rpmsg_endpoint *ns_ept;
@@ -234,9 +232,9 @@ static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp,
 						 rpmsg_rx_cb_t cb,
 						 void *priv, u32 addr)
 {
-	int id_min, id_max, id;
 	struct rpmsg_endpoint *ept;
 	struct device *dev = rpdev ? &rpdev->dev : &vrp->vdev->dev;
+	int err;
 
 	ept = kzalloc(sizeof(*ept), GFP_KERNEL);
 	if (!ept)
@@ -250,33 +248,23 @@ static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp,
 	ept->priv = priv;
 	ept->ops = &virtio_endpoint_ops;
 
-	/* do we need to allocate a local address ? */
+	/* bind the endpoint to an rpmsg address (and allocate one if needed) */
 	if (addr == RPMSG_ADDR_ANY) {
-		id_min = RPMSG_RESERVED_ADDRESSES;
-		id_max = 0;
+		err = xa_alloc(&vrp->endpoints, &ept->addr, ept,
+				XA_LIMIT(RPMSG_RESERVED_ADDRESSES, INT_MAX),
+				GFP_KERNEL);
 	} else {
-		id_min = addr;
-		id_max = addr + 1;
+		ept->addr = addr;
+		err = xa_insert(&vrp->endpoints, addr, ept, GFP_KERNEL);
 	}
 
-	mutex_lock(&vrp->endpoints_lock);
-
-	/* bind the endpoint to an rpmsg address (and allocate one if needed) */
-	id = idr_alloc(&vrp->endpoints, ept, id_min, id_max, GFP_KERNEL);
-	if (id < 0) {
-		dev_err(dev, "idr_alloc failed: %d\n", id);
-		goto free_ept;
+	if (err < 0) {
+		dev_err(dev, "address busy: %d\n", err);
+		kref_put(&ept->refcount, __ept_release);
+		ept = NULL;
 	}
-	ept->addr = id;
-
-	mutex_unlock(&vrp->endpoints_lock);
 
 	return ept;
-
-free_ept:
-	mutex_unlock(&vrp->endpoints_lock);
-	kref_put(&ept->refcount, __ept_release);
-	return NULL;
 }
 
 static struct rpmsg_endpoint *virtio_rpmsg_create_ept(struct rpmsg_device *rpdev,
@@ -303,9 +291,7 @@ static void
 __rpmsg_destroy_ept(struct virtproc_info *vrp, struct rpmsg_endpoint *ept)
 {
 	/* make sure new inbound messages can't find this ept anymore */
-	mutex_lock(&vrp->endpoints_lock);
-	idr_remove(&vrp->endpoints, ept->addr);
-	mutex_unlock(&vrp->endpoints_lock);
+	xa_erase(&vrp->endpoints, ept->addr);
 
 	/* make sure in-flight inbound messages won't invoke cb anymore */
 	mutex_lock(&ept->cb_lock);
@@ -724,15 +710,13 @@ static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,
 	}
 
 	/* use the dst addr to fetch the callback of the appropriate user */
-	mutex_lock(&vrp->endpoints_lock);
-
-	ept = idr_find(&vrp->endpoints, msg->dst);
+	xa_lock(&vrp->endpoints);
+	ept = xa_load(&vrp->endpoints, msg->dst);
 
 	/* let's make sure no one deallocates ept while we use it */
 	if (ept)
 		kref_get(&ept->refcount);
-
-	mutex_unlock(&vrp->endpoints_lock);
+	xa_unlock(&vrp->endpoints);
 
 	if (ept) {
 		/* make sure ept->cb doesn't go away while we use it */
@@ -884,8 +868,7 @@ static int rpmsg_probe(struct virtio_device *vdev)
 
 	vrp->vdev = vdev;
 
-	idr_init(&vrp->endpoints);
-	mutex_init(&vrp->endpoints_lock);
+	xa_init_flags(&vrp->endpoints, XA_FLAGS_ALLOC);
 	mutex_init(&vrp->tx_lock);
 	init_waitqueue_head(&vrp->sendq);
 
@@ -1011,8 +994,6 @@ static void rpmsg_remove(struct virtio_device *vdev)
 	if (vrp->ns_ept)
 		__rpmsg_destroy_ept(vrp, vrp->ns_ept);
 
-	idr_destroy(&vrp->endpoints);
-
 	vdev->config->del_vqs(vrp->vdev);
 
 	dma_free_coherent(vdev->dev.parent, total_buf_space,