1 files changed, 29 insertions, 25 deletions

diff --git a/drivers/uio/uio_pdrv_genirq.c b/drivers/uio/uio_pdrv_genirq.c
index c122bca669b6..4eb8eaf71be8 100644
--- a/drivers/uio/uio_pdrv_genirq.c
+++ b/drivers/uio/uio_pdrv_genirq.c
@@ -37,6 +37,11 @@ struct uio_pdrv_genirq_platdata {
 	struct platform_device *pdev;
 };
 
+/* Bits in uio_pdrv_genirq_platdata.flags */
+enum {
+	UIO_IRQ_DISABLED = 0,
+};
+
 static int uio_pdrv_genirq_open(struct uio_info *info, struct inode *inode)
 {
 	struct uio_pdrv_genirq_platdata *priv = info->priv;
@@ -63,8 +68,10 @@ static irqreturn_t uio_pdrv_genirq_handler(int irq, struct uio_info *dev_info)
 	 * remember the state so we can allow user space to enable it later.
 	 */
 
-	if (!test_and_set_bit(0, &priv->flags))
+	spin_lock(&priv->lock);
+	if (!__test_and_set_bit(UIO_IRQ_DISABLED, &priv->flags))
 		disable_irq_nosync(irq);
+	spin_unlock(&priv->lock);
 
 	return IRQ_HANDLED;
 }
@@ -78,16 +85,17 @@ static int uio_pdrv_genirq_irqcontrol(struct uio_info *dev_info, s32 irq_on)
 	 * in the interrupt controller, but keep track of the
 	 * state to prevent per-irq depth damage.
 	 *
-	 * Serialize this operation to support multiple tasks.
+	 * Serialize this operation to support multiple tasks and concurrency
+	 * with irq handler on SMP systems.
 	 */
 
 	spin_lock_irqsave(&priv->lock, flags);
 	if (irq_on) {
-		if (test_and_clear_bit(0, &priv->flags))
+		if (__test_and_clear_bit(UIO_IRQ_DISABLED, &priv->flags))
 			enable_irq(dev_info->irq);
 	} else {
-		if (!test_and_set_bit(0, &priv->flags))
-			disable_irq(dev_info->irq);
+		if (!__test_and_set_bit(UIO_IRQ_DISABLED, &priv->flags))
+			disable_irq_nosync(dev_info->irq);
 	}
 	spin_unlock_irqrestore(&priv->lock, flags);
 
@@ -103,24 +111,16 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev)
 	int i;
 
 	if (pdev->dev.of_node) {
-		int irq;
-
 		/* alloc uioinfo for one device */
 		uioinfo = kzalloc(sizeof(*uioinfo), GFP_KERNEL);
 		if (!uioinfo) {
 			ret = -ENOMEM;
 			dev_err(&pdev->dev, "unable to kmalloc\n");
-			goto bad2;
+			return ret;
 		}
 		uioinfo->name = pdev->dev.of_node->name;
 		uioinfo->version = "devicetree";
-
 		/* Multiple IRQs are not supported */
-		irq = platform_get_irq(pdev, 0);
-		if (irq == -ENXIO)
-			uioinfo->irq = UIO_IRQ_NONE;
-		else
-			uioinfo->irq = irq;
 	}
 
 	if (!uioinfo || !uioinfo->name || !uioinfo->version) {
@@ -148,12 +148,15 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev)
 
 	if (!uioinfo->irq) {
 		ret = platform_get_irq(pdev, 0);
-		if (ret < 0) {
+		uioinfo->irq = ret;
+		if (ret == -ENXIO && pdev->dev.of_node)
+			uioinfo->irq = UIO_IRQ_NONE;
+		else if (ret < 0) {
 			dev_err(&pdev->dev, "failed to get IRQ\n");
-			goto bad0;
+			goto bad1;
 		}
-		uioinfo->irq = ret;
 	}
+
 	uiomem = &uioinfo->mem[0];
 
 	for (i = 0; i < pdev->num_resources; ++i) {
@@ -206,19 +209,19 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev)
 	ret = uio_register_device(&pdev->dev, priv->uioinfo);
 	if (ret) {
 		dev_err(&pdev->dev, "unable to register uio device\n");
-		goto bad1;
+		goto bad2;
 	}
 
 	platform_set_drvdata(pdev, priv);
 	return 0;
+ bad2:
+	pm_runtime_disable(&pdev->dev);
  bad1:
 	kfree(priv);
-	pm_runtime_disable(&pdev->dev);
  bad0:
 	/* kfree uioinfo for OF */
 	if (pdev->dev.of_node)
 		kfree(uioinfo);
- bad2:
 	return ret;
 }
 
@@ -263,12 +266,13 @@ static const struct dev_pm_ops uio_pdrv_genirq_dev_pm_ops = {
 };
 
 #ifdef CONFIG_OF
-static const struct of_device_id uio_of_genirq_match[] = {
-	{ /* empty for now */ },
+static struct of_device_id uio_of_genirq_match[] = {
+	{ /* This is filled with module_parm */ },
+	{ /* Sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, uio_of_genirq_match);
-#else
-# define uio_of_genirq_match NULL
+module_param_string(of_id, uio_of_genirq_match[0].compatible, 128, 0);
+MODULE_PARM_DESC(of_id, "Openfirmware id of the device to be handled by uio");
 #endif
 
 static struct platform_driver uio_pdrv_genirq = {
@@ -278,7 +282,7 @@ static struct platform_driver uio_pdrv_genirq = {
 		.name = DRIVER_NAME,
 		.owner = THIS_MODULE,
 		.pm = &uio_pdrv_genirq_dev_pm_ops,
-		.of_match_table = uio_of_genirq_match,
+		.of_match_table = of_match_ptr(uio_of_genirq_match),
 	},
 };