1 files changed, 18 insertions, 104 deletions

diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c
index cfb54e01d758..9d27016c899e 100644
--- a/drivers/rapidio/devices/rio_mport_cdev.c
+++ b/drivers/rapidio/devices/rio_mport_cdev.c
@@ -212,7 +212,6 @@ struct mport_cdev_priv {
 #ifdef CONFIG_RAPIDIO_DMA_ENGINE
 	struct dma_chan		*dmach;
 	struct list_head	async_list;
-	struct list_head	pend_list;
 	spinlock_t              req_lock;
 	struct mutex		dma_lock;
 	struct kref		dma_ref;
@@ -258,8 +257,6 @@ static DECLARE_WAIT_QUEUE_HEAD(mport_cdev_wait);
 static struct class *dev_class;
 static dev_t dev_number;
 
-static struct workqueue_struct *dma_wq;
-
 static void mport_release_mapping(struct kref *ref);
 
 static int rio_mport_maint_rd(struct mport_cdev_priv *priv, void __user *arg,
@@ -539,6 +536,7 @@ static int maint_comptag_set(struct mport_cdev_priv *priv, void __user *arg)
 #ifdef CONFIG_RAPIDIO_DMA_ENGINE
 
 struct mport_dma_req {
+	struct kref refcount;
 	struct list_head node;
 	struct file *filp;
 	struct mport_cdev_priv *priv;
@@ -554,11 +552,6 @@ struct mport_dma_req {
 	struct completion req_comp;
 };
 
-struct mport_faf_work {
-	struct work_struct work;
-	struct mport_dma_req *req;
-};
-
 static void mport_release_def_dma(struct kref *dma_ref)
 {
 	struct mport_dev *md =
@@ -578,8 +571,10 @@ static void mport_release_dma(struct kref *dma_ref)
 	complete(&priv->comp);
 }
 
-static void dma_req_free(struct mport_dma_req *req)
+static void dma_req_free(struct kref *ref)
 {
+	struct mport_dma_req *req = container_of(ref, struct mport_dma_req,
+			refcount);
 	struct mport_cdev_priv *priv = req->priv;
 	unsigned int i;
 
@@ -611,30 +606,7 @@ static void dma_xfer_callback(void *param)
 	req->status = dma_async_is_tx_complete(priv->dmach, req->cookie,
 					       NULL, NULL);
 	complete(&req->req_comp);
-}
-
-static void dma_faf_cleanup(struct work_struct *_work)
-{
-	struct mport_faf_work *work = container_of(_work,
-						struct mport_faf_work, work);
-	struct mport_dma_req *req = work->req;
-
-	dma_req_free(req);
-	kfree(work);
-}
-
-static void dma_faf_callback(void *param)
-{
-	struct mport_dma_req *req = (struct mport_dma_req *)param;
-	struct mport_faf_work *work;
-
-	work = kmalloc(sizeof(*work), GFP_ATOMIC);
-	if (!work)
-		return;
-
-	INIT_WORK(&work->work, dma_faf_cleanup);
-	work->req = req;
-	queue_work(dma_wq, &work->work);
+	kref_put(&req->refcount, dma_req_free);
 }
 
 /*
@@ -765,16 +737,14 @@ static int do_dma_request(struct mport_dma_req *req,
 		goto err_out;
 	}
 
-	if (sync == RIO_TRANSFER_FAF)
-		tx->callback = dma_faf_callback;
-	else
-		tx->callback = dma_xfer_callback;
+	tx->callback = dma_xfer_callback;
 	tx->callback_param = req;
 
 	req->dmach = chan;
 	req->sync = sync;
 	req->status = DMA_IN_PROGRESS;
 	init_completion(&req->req_comp);
+	kref_get(&req->refcount);
 
 	cookie = dmaengine_submit(tx);
 	req->cookie = cookie;
@@ -785,6 +755,7 @@ static int do_dma_request(struct mport_dma_req *req,
 	if (dma_submit_error(cookie)) {
 		rmcd_error("submit err=%d (addr:0x%llx len:0x%llx)",
 			   cookie, xfer->rio_addr, xfer->length);
+		kref_put(&req->refcount, dma_req_free);
 		ret = -EIO;
 		goto err_out;
 	}
@@ -860,6 +831,8 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode,
 	if (!req)
 		return -ENOMEM;
 
+	kref_init(&req->refcount);
+
 	ret = get_dma_channel(priv);
 	if (ret) {
 		kfree(req);
@@ -968,42 +941,20 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode,
 	ret = do_dma_request(req, xfer, sync, nents);
 
 	if (ret >= 0) {
-		if (sync == RIO_TRANSFER_SYNC)
-			goto sync_out;
-		return ret; /* return ASYNC cookie */
-	}
-
-	if (ret == -ETIMEDOUT || ret == -EINTR) {
-		/*
-		 * This can happen only in case of SYNC transfer.
-		 * Do not free unfinished request structure immediately.
-		 * Place it into pending list and deal with it later
-		 */
-		spin_lock(&priv->req_lock);
-		list_add_tail(&req->node, &priv->pend_list);
-		spin_unlock(&priv->req_lock);
-		return ret;
+		if (sync == RIO_TRANSFER_ASYNC)
+			return ret; /* return ASYNC cookie */
+	} else {
+		rmcd_debug(DMA, "do_dma_request failed with err=%d", ret);
 	}
 
-
-	rmcd_debug(DMA, "do_dma_request failed with err=%d", ret);
-sync_out:
-	dma_unmap_sg(chan->device->dev, req->sgt.sgl, req->sgt.nents, dir);
-	sg_free_table(&req->sgt);
 err_pg:
-	if (page_list) {
+	if (!req->page_list) {
 		for (i = 0; i < nr_pages; i++)
 			put_page(page_list[i]);
 		kfree(page_list);
 	}
 err_req:
-	if (req->map) {
-		mutex_lock(&md->buf_mutex);
-		kref_put(&req->map->ref, mport_release_mapping);
-		mutex_unlock(&md->buf_mutex);
-	}
-	put_dma_channel(priv);
-	kfree(req);
+	kref_put(&req->refcount, dma_req_free);
 	return ret;
 }
 
@@ -1121,7 +1072,7 @@ static int rio_mport_wait_for_async_dma(struct file *filp, void __user *arg)
 		ret = 0;
 
 	if (req->status != DMA_IN_PROGRESS && req->status != DMA_PAUSED)
-		dma_req_free(req);
+		kref_put(&req->refcount, dma_req_free);
 
 	return ret;
 
@@ -1966,7 +1917,6 @@ static int mport_cdev_open(struct inode *inode, struct file *filp)
 
 #ifdef CONFIG_RAPIDIO_DMA_ENGINE
 	INIT_LIST_HEAD(&priv->async_list);
-	INIT_LIST_HEAD(&priv->pend_list);
 	spin_lock_init(&priv->req_lock);
 	mutex_init(&priv->dma_lock);
 #endif
@@ -2006,8 +1956,6 @@ static void mport_cdev_release_dma(struct file *filp)
 
 	md = priv->md;
 
-	flush_workqueue(dma_wq);
-
 	spin_lock(&priv->req_lock);
 	if (!list_empty(&priv->async_list)) {
 		rmcd_debug(EXIT, "async list not empty filp=%p %s(%d)",
@@ -2023,20 +1971,7 @@ static void mport_cdev_release_dma(struct file *filp)
 				   req->filp, req->cookie,
 				   completion_done(&req->req_comp)?"yes":"no");
 			list_del(&req->node);
-			dma_req_free(req);
-		}
-	}
-
-	if (!list_empty(&priv->pend_list)) {
-		rmcd_debug(EXIT, "Free pending DMA requests for filp=%p %s(%d)",
-			   filp, current->comm, task_pid_nr(current));
-		list_for_each_entry_safe(req,
-					 req_next, &priv->pend_list, node) {
-			rmcd_debug(EXIT, "free req->filp=%p cookie=%d compl=%s",
-				   req->filp, req->cookie,
-				   completion_done(&req->req_comp)?"yes":"no");
-			list_del(&req->node);
-			dma_req_free(req);
+			kref_put(&req->refcount, dma_req_free);
 		}
 	}
 
@@ -2048,15 +1983,6 @@ static void mport_cdev_release_dma(struct file *filp)
 			current->comm, task_pid_nr(current), wret);
 	}
 
-	spin_lock(&priv->req_lock);
-
-	if (!list_empty(&priv->pend_list)) {
-		rmcd_debug(EXIT, "ATTN: pending DMA requests, filp=%p %s(%d)",
-			   filp, current->comm, task_pid_nr(current));
-	}
-
-	spin_unlock(&priv->req_lock);
-
 	if (priv->dmach != priv->md->dma_chan) {
 		rmcd_debug(EXIT, "Release DMA channel for filp=%p %s(%d)",
 			   filp, current->comm, task_pid_nr(current));
@@ -2573,8 +2499,6 @@ static void mport_cdev_remove(struct mport_dev *md)
 	cdev_device_del(&md->cdev, &md->dev);
 	mport_cdev_kill_fasync(md);
 
-	flush_workqueue(dma_wq);
-
 	/* TODO: do we need to give clients some time to close file
 	 * descriptors? Simple wait for XX, or kref?
 	 */
@@ -2691,17 +2615,8 @@ static int __init mport_init(void)
 		goto err_cli;
 	}
 
-	dma_wq = create_singlethread_workqueue("dma_wq");
-	if (!dma_wq) {
-		rmcd_error("failed to create DMA work queue");
-		ret = -ENOMEM;
-		goto err_wq;
-	}
-
 	return 0;
 
-err_wq:
-	class_interface_unregister(&rio_mport_interface);
 err_cli:
 	unregister_chrdev_region(dev_number, RIO_MAX_MPORTS);
 err_chr:
@@ -2717,7 +2632,6 @@ static void __exit mport_exit(void)
 	class_interface_unregister(&rio_mport_interface);
 	class_destroy(dev_class);
 	unregister_chrdev_region(dev_number, RIO_MAX_MPORTS);
-	destroy_workqueue(dma_wq);
 }
 
 module_init(mport_init);