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path: root/drivers/uio/uio_dmem_genirq.c
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Diffstat (limited to 'drivers/uio/uio_dmem_genirq.c')
-rw-r--r--drivers/uio/uio_dmem_genirq.c22
1 files changed, 14 insertions, 8 deletions
diff --git a/drivers/uio/uio_dmem_genirq.c b/drivers/uio/uio_dmem_genirq.c
index 1106f3376404..5313307c2754 100644
--- a/drivers/uio/uio_dmem_genirq.c
+++ b/drivers/uio/uio_dmem_genirq.c
@@ -41,6 +41,11 @@ struct uio_dmem_genirq_platdata {
unsigned int refcnt;
};
+/* Bits in uio_dmem_genirq_platdata.flags */
+enum {
+ UIO_IRQ_DISABLED = 0,
+};
+
static int uio_dmem_genirq_open(struct uio_info *info, struct inode *inode)
{
struct uio_dmem_genirq_platdata *priv = info->priv;
@@ -110,8 +115,10 @@ static irqreturn_t uio_dmem_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;
}
@@ -125,20 +132,19 @@ static int uio_dmem_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);
- spin_unlock_irqrestore(&priv->lock, flags);
} else {
- if (!test_and_set_bit(0, &priv->flags)) {
- spin_unlock_irqrestore(&priv->lock, 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);
return 0;
}