memstick: use fully asynchronous request processing

Instead of using a separate thread to pump requests from block layer queue
to memstick, do so inline, utilizing the callback design of the memstick.

[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/memstick/core/memstick.c

@@ -249,8 +249,11 @@ EXPORT_SYMBOL(memstick_next_req);
  */
 void memstick_new_req(struct memstick_host *host)
 {
-	host->retries = cmd_retries;
-	host->request(host);
+	if (host->card) {
+		host->retries = cmd_retries;
+		INIT_COMPLETION(host->card->mrq_complete);
+		host->request(host);
+	}
 }
 EXPORT_SYMBOL(memstick_new_req);
 

drivers/memstick/host/jmb38x_ms.c

@@ -50,6 +50,7 @@ struct jmb38x_ms_host {
 	struct jmb38x_ms        *chip;
 	void __iomem            *addr;
 	spinlock_t              lock;
+	struct tasklet_struct   notify;
 	int                     id;
 	char                    host_id[32];
 	int                     irq;
@@ -590,25 +591,35 @@ static void jmb38x_ms_abort(unsigned long data)
 	spin_unlock_irqrestore(&host->lock, flags);
 }
 
-static void jmb38x_ms_request(struct memstick_host *msh)
+static void jmb38x_ms_req_tasklet(unsigned long data)
 {
+	struct memstick_host *msh = (struct memstick_host *)data;
 	struct jmb38x_ms_host *host = memstick_priv(msh);
 	unsigned long flags;
 	int rc;
 
 	spin_lock_irqsave(&host->lock, flags);
-	if (host->req) {
-		spin_unlock_irqrestore(&host->lock, flags);
-		BUG();
-		return;
+	if (!host->req) {
+		do {
+			rc = memstick_next_req(msh, &host->req);
+			dev_dbg(&host->chip->pdev->dev, "tasklet req %d\n", rc);
+		} while (!rc && jmb38x_ms_issue_cmd(msh));
 	}
-
-	do {
-		rc = memstick_next_req(msh, &host->req);
-	} while (!rc && jmb38x_ms_issue_cmd(msh));
 	spin_unlock_irqrestore(&host->lock, flags);
 }
 
+static void jmb38x_ms_dummy_submit(struct memstick_host *msh)
+{
+	return;
+}
+
+static void jmb38x_ms_submit_req(struct memstick_host *msh)
+{
+	struct jmb38x_ms_host *host = memstick_priv(msh);
+
+	tasklet_schedule(&host->notify);
+}
+
 static int jmb38x_ms_reset(struct jmb38x_ms_host *host)
 {
 	int cnt;
@@ -816,7 +827,9 @@ static struct memstick_host *jmb38x_ms_alloc_host(struct jmb38x_ms *jm, int cnt)
 		 host->id);
 	host->irq = jm->pdev->irq;
 	host->timeout_jiffies = msecs_to_jiffies(1000);
-	msh->request = jmb38x_ms_request;
+
+	tasklet_init(&host->notify, jmb38x_ms_req_tasklet, (unsigned long)msh);
+	msh->request = jmb38x_ms_submit_req;
 	msh->set_param = jmb38x_ms_set_param;
 
 	msh->caps = MEMSTICK_CAP_PAR4 | MEMSTICK_CAP_PAR8;
@@ -928,6 +941,8 @@ static void jmb38x_ms_remove(struct pci_dev *dev)
 
 		host = memstick_priv(jm->hosts[cnt]);
 
+		jm->hosts[cnt]->request = jmb38x_ms_dummy_submit;
+		tasklet_kill(&host->notify);
 		writel(0, host->addr + INT_SIGNAL_ENABLE);
 		writel(0, host->addr + INT_STATUS_ENABLE);
 		mmiowb();

drivers/memstick/host/tifm_ms.c

@@ -71,6 +71,7 @@ struct tifm_ms {
 	struct tifm_dev         *dev;
 	struct timer_list       timer;
 	struct memstick_request *req;
+	struct tasklet_struct   notify;
 	unsigned int            mode_mask;
 	unsigned int            block_pos;
 	unsigned long           timeout_jiffies;
@@ -455,40 +456,45 @@ static void tifm_ms_card_event(struct tifm_dev *sock)
 	return;
 }
 
-static void tifm_ms_request(struct memstick_host *msh)
+static void tifm_ms_req_tasklet(unsigned long data)
 {
+	struct memstick_host *msh = (struct memstick_host *)data;
 	struct tifm_ms *host = memstick_priv(msh);
 	struct tifm_dev *sock = host->dev;
 	unsigned long flags;
 	int rc;
 
 	spin_lock_irqsave(&sock->lock, flags);
-	if (host->req) {
-		printk(KERN_ERR "%s : unfinished request detected\n",
-		       sock->dev.bus_id);
-		spin_unlock_irqrestore(&sock->lock, flags);
-		tifm_eject(host->dev);
-		return;
-	}
+	if (!host->req) {
+		if (host->eject) {
+			do {
+				rc = memstick_next_req(msh, &host->req);
+				if (!rc)
+					host->req->error = -ETIME;
+			} while (!rc);
+			spin_unlock_irqrestore(&sock->lock, flags);
+			return;
+		}
 
-	if (host->eject) {
 		do {
 			rc = memstick_next_req(msh, &host->req);
-			if (!rc)
-				host->req->error = -ETIME;
-		} while (!rc);
-		spin_unlock_irqrestore(&sock->lock, flags);
-		return;
+		} while (!rc && tifm_ms_issue_cmd(host));
 	}
-
-	do {
-		rc = memstick_next_req(msh, &host->req);
-	} while (!rc && tifm_ms_issue_cmd(host));
-
 	spin_unlock_irqrestore(&sock->lock, flags);
+}
+
+static void tifm_ms_dummy_submit(struct memstick_host *msh)
+{
 	return;
 }
 
+static void tifm_ms_submit_req(struct memstick_host *msh)
+{
+	struct tifm_ms *host = memstick_priv(msh);
+
+	tasklet_schedule(&host->notify);
+}
+
 static int tifm_ms_set_param(struct memstick_host *msh,
 			     enum memstick_param param,
 			     int value)
@@ -569,8 +575,9 @@ static int tifm_ms_probe(struct tifm_dev *sock)
 	host->timeout_jiffies = msecs_to_jiffies(1000);
 
 	setup_timer(&host->timer, tifm_ms_abort, (unsigned long)host);
+	tasklet_init(&host->notify, tifm_ms_req_tasklet, (unsigned long)msh);
 
-	msh->request = tifm_ms_request;
+	msh->request = tifm_ms_submit_req;
 	msh->set_param = tifm_ms_set_param;
 	sock->card_event = tifm_ms_card_event;
 	sock->data_event = tifm_ms_data_event;
@@ -592,6 +599,8 @@ static void tifm_ms_remove(struct tifm_dev *sock)
 	int rc = 0;
 	unsigned long flags;
 
+	msh->request = tifm_ms_dummy_submit;
+	tasklet_kill(&host->notify);
 	spin_lock_irqsave(&sock->lock, flags);
 	host->eject = 1;
 	if (host->req) {