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SubjectRe: [PATCH v3 03/10] VFIO: platform: single handler using function pointer
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On Mon, 2015-08-10 at 15:20 +0200, Eric Auger wrote:
> A single handler now is registered whatever the use case: automasked
> or not. A function pointer is set according to the wished behavior
> and the handler calls this function.
>
> The irq lock is taken/released in the root handler. eventfd_signal can
> be called in regions not allowed to sleep.
>
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>
> ---
>
> v4: creation
> ---
> drivers/vfio/platform/vfio_platform_irq.c | 21 +++++++++++++++------
> drivers/vfio/platform/vfio_platform_private.h | 1 +
> 2 files changed, 16 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
> index 40f057a..b31b1f0 100644
> --- a/drivers/vfio/platform/vfio_platform_irq.c
> +++ b/drivers/vfio/platform/vfio_platform_irq.c
> @@ -148,11 +148,8 @@ static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev,
> static irqreturn_t vfio_automasked_irq_handler(int irq, void *dev_id)
> {
> struct vfio_platform_irq *irq_ctx = dev_id;
> - unsigned long flags;
> int ret = IRQ_NONE;
>
> - spin_lock_irqsave(&irq_ctx->lock, flags);
> -
> if (!irq_ctx->masked) {
> ret = IRQ_HANDLED;
>
> @@ -161,8 +158,6 @@ static irqreturn_t vfio_automasked_irq_handler(int irq, void *dev_id)
> irq_ctx->masked = true;
> }
>
> - spin_unlock_irqrestore(&irq_ctx->lock, flags);
> -
> if (ret == IRQ_HANDLED)
> eventfd_signal(irq_ctx->trigger, 1);

Has this been run with lockdep to check whether this is safe to call
with spinlock_irqsave held?

>
> @@ -178,6 +173,19 @@ static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
> return IRQ_HANDLED;
> }
>
> +static irqreturn_t vfio_handler(int irq, void *dev_id)
> +{
> + struct vfio_platform_irq *irq_ctx = dev_id;
> + unsigned long flags;
> + irqreturn_t ret;
> +
> + spin_lock_irqsave(&irq_ctx->lock, flags);
> + ret = irq_ctx->handler(irq, dev_id);
> + spin_unlock_irqrestore(&irq_ctx->lock, flags);
> +
> + return ret;
> +}
> +
> static void vfio_platform_irq_bypass_stop(struct irq_bypass_producer *prod)
> {
> }
> @@ -229,9 +237,10 @@ static int vfio_set_trigger(struct vfio_platform_device *vdev, int index,
> }
>
> irq->trigger = trigger;
> + irq->handler = handler;
>
> irq_set_status_flags(irq->hwirq, IRQ_NOAUTOEN);
> - ret = request_irq(irq->hwirq, handler, 0, irq->name, irq);
> + ret = request_irq(irq->hwirq, vfio_handler, 0, irq->name, irq);
> if (ret) {
> kfree(irq->name);
> eventfd_ctx_put(trigger);
> diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
> index 8b4f814..f848a6b 100644
> --- a/drivers/vfio/platform/vfio_platform_private.h
> +++ b/drivers/vfio/platform/vfio_platform_private.h
> @@ -40,6 +40,7 @@ struct vfio_platform_irq {
> struct virqfd *mask;
> struct irq_bypass_producer producer;
> bool forwarded;
> + irqreturn_t (*handler)(int irq, void *dev_id);
> };
>
> struct vfio_platform_region {





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