uio: uio_dmem_genirq: Use non-atomic bit operations in irq config and handling

This finishes the port of the irq configuration and handling from
"uio_pdrv_genirq" to "uio_dmem_genirq". It changes the atomic
bit-manipulation routines to their non-atomic counterparts as we are
already guarding the code by spinlock.

Split out from commit 34cb27528398 ("UIO: Fix concurrency issue").

Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Link: https://lore.kernel.org/r/20220930224100.816175-4-rafaelmendsr@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/uio/uio_dmem_genirq.c b/drivers/uio/uio_dmem_genirq.c
index 792c3e9c9ce536b5e98e3368d8894c827ceca8f7..5313307c2754a8c66ee013687acd7e4bf893aed0 100644 (file)
--- 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;
@@ -111,7 +116,7 @@ static irqreturn_t uio_dmem_genirq_handler(int irq, struct uio_info *dev_info)
         */
 
        spin_lock(&priv->lock);
-       if (!test_and_set_bit(0, &priv->flags))
+       if (!__test_and_set_bit(UIO_IRQ_DISABLED, &priv->flags))
                disable_irq_nosync(irq);
        spin_unlock(&priv->lock);
 
@@ -133,10 +138,10 @@ static int uio_dmem_genirq_irqcontrol(struct uio_info *dev_info, s32 irq_on)
 
        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))
+               if (!__test_and_set_bit(UIO_IRQ_DISABLED, &priv->flags))
                        disable_irq_nosync(dev_info->irq);
        }
        spin_unlock_irqrestore(&priv->lock, flags);