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; + 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 { -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
