On Tue, 2014-09-23 at 16:46 +0200, Antonios Motakis wrote:
> This patch allows to set an eventfd for a patform device's interrupt,
> and also to trigger the interrupt eventfd from userspace for testing.
>
> Signed-off-by: Antonios Motakis <[email protected]>
> ---
> drivers/vfio/platform/vfio_platform_irq.c | 89
> ++++++++++++++++++++++++++-
> drivers/vfio/platform/vfio_platform_private.h | 2 +
> 2 files changed, 89 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vfio/platform/vfio_platform_irq.c
> b/drivers/vfio/platform/vfio_platform_irq.c
> index 007b386..25a7825 100644
> --- a/drivers/vfio/platform/vfio_platform_irq.c
> +++ b/drivers/vfio/platform/vfio_platform_irq.c
> @@ -45,11 +45,91 @@ static int vfio_platform_set_irq_unmask(struct
> vfio_platform_device *vdev,
> return -EINVAL;
> }
>
> +static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
> +{
> + struct vfio_platform_irq *irq_ctx = dev_id;
> +
> + eventfd_signal(irq_ctx->trigger, 1);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int vfio_set_trigger(struct vfio_platform_device *vdev,
> + int index, int fd)
> +{
> + struct vfio_platform_irq *irq = &vdev->irqs[index];
> + struct eventfd_ctx *trigger;
> + int ret;
> +
> + if (irq->trigger) {
> + free_irq(irq->hwirq, irq);
> + kfree(irq->name);
> + eventfd_ctx_put(irq->trigger);
> + irq->trigger = NULL;
> + }
> +
> + if (fd < 0) /* Disable only */
> + return 0;
> +
> + irq->name = kasprintf(GFP_KERNEL, "vfio-irq[%d](%s)",
> + irq->hwirq, vdev->name);
> + if (!irq->name)
> + return -ENOMEM;
> +
> + trigger = eventfd_ctx_fdget(fd);
> + if (IS_ERR(trigger)) {
> + kfree(irq->name);
> + return PTR_ERR(trigger);
> + }
> +
> + irq->trigger = trigger;
> +
> + ret = request_irq(irq->hwirq, vfio_irq_handler, 0, irq->name, irq);
> + if (ret) {
> + kfree(irq->name);
> + eventfd_ctx_put(trigger);
> + irq->trigger = NULL;
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev,
> unsigned index, unsigned start,
> unsigned count, uint32_t flags, void *data)
> {
> - return -EINVAL;
> + struct vfio_platform_irq *irq = &vdev->irqs[index];
> + uint8_t irq_bitmap;
Minor nit here and also present in the next patch, I believe when we
have DATA_BOOL, it's defined to be a u8 array, where each byte is a
bool, not each bit. So it's not actually a bitmap. The PCI code
handles any non-zero byte as true, not just bit0. Thanks,
Alex
> + int32_t fd;
> +
> + switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
> + case VFIO_IRQ_SET_DATA_NONE:
> + if (count == 0)
> + return vfio_set_trigger(vdev, index, -1);
> +
> + vfio_irq_handler(irq->hwirq, irq);
> + return 0;
> +
> + case VFIO_IRQ_SET_DATA_BOOL:
> + if (copy_from_user(&irq_bitmap, data, sizeof(uint8_t)))
> + return -EFAULT;
> +
> + if (irq_bitmap == 0x1) {
> + vfio_irq_handler(irq->hwirq, irq);
> + return 0;
> + }
> +
> + return -EINVAL;
> +
> + case VFIO_IRQ_SET_DATA_EVENTFD:
> + if (copy_from_user(&fd, data, sizeof(int32_t)))
> + return -EFAULT;
> +
> + return vfio_set_trigger(vdev, index, fd);
> + }
> +
> + return -EFAULT;
> }
>
> int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
> @@ -95,7 +175,7 @@ int vfio_platform_irq_init(struct vfio_platform_device
> *vdev)
> if (hwirq < 0)
> goto err;
>
> - vdev->irqs[i].flags = 0;
> + vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD;
> vdev->irqs[i].count = 1;
> vdev->irqs[i].hwirq = hwirq;
> }
> @@ -110,6 +190,11 @@ err:
>
> void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev)
> {
> + int i;
> +
> + for (i = 0; i < vdev->num_irqs; i++)
> + vfio_set_trigger(vdev, i, -1);
> +
> vdev->num_irqs = 0;
> kfree(vdev->irqs);
> }
> diff --git a/drivers/vfio/platform/vfio_platform_private.h
> b/drivers/vfio/platform/vfio_platform_private.h
> index 4201b94..765b371 100644
> --- a/drivers/vfio/platform/vfio_platform_private.h
> +++ b/drivers/vfio/platform/vfio_platform_private.h
> @@ -28,6 +28,8 @@ struct vfio_platform_irq {
> u32 flags;
> u32 count;
> int hwirq;
> + char *name;
> + struct eventfd_ctx *trigger;
> };
>
> struct vfio_platform_region {
--
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