[RFC PATCH v4 10/10] VFIO_PLATFORM: Support for maskable and automasked interrupts

Antonios Motakis
2014-02-08T17:34:24Z

Adds support to mask interrupts, and also for automasked interrupts.
Level sensitive interrupts are exposed as automasked interrupts and
are masked and disabled automatically when they fire.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Tested-by: Alvise Rigo <a.rigo@virtualopensystems.com>
---
drivers/vfio/platform/vfio_platform_irq.c | 117 ++++++++++++++++++++++++--
drivers/vfio/platform/vfio_platform_private.h | 2 +
2 files changed, 113 insertions(+), 6 deletions(-)

diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
index 433edc1..e38982f 100644
--- a/drivers/vfio/platform/vfio_platform_irq.c
+++ b/drivers/vfio/platform/vfio_platform_irq.c
@@ -52,9 +52,16 @@ int vfio_platform_irq_init(struct vfio_platform_device *vdev)
struct vfio_platform_irq irq;
int hwirq = platform_get_irq(vdev->pdev, i);

- irq.flags = VFIO_IRQ_INFO_EVENTFD;
+ spin_lock_init(&irq.lock);
+
+ irq.flags = VFIO_IRQ_INFO_EVENTFD | VFIO_IRQ_INFO_MASKABLE;
+
+ if (irq_get_trigger_type(hwirq) & IRQ_TYPE_LEVEL_MASK)
+ irq.flags |= VFIO_IRQ_INFO_AUTOMASKED;
+
irq.count = 1;
irq.hwirq = hwirq;
+ irq.masked = false;

vdev->irq[i] = irq;
}
@@ -66,19 +73,39 @@ void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev)
{
int i;

- for (i = 0; i < vdev->num_irqs; i++)
+ for (i = 0; i < vdev->num_irqs; i++) {
vfio_set_trigger(vdev, i, -1);

+ if (vdev->irq[i].masked)
+ enable_irq(vdev->irq[i].hwirq);
+ }
+
kfree(vdev->irq);
}

static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
{
- struct eventfd_ctx *trigger = 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;
+
+ if (irq_ctx->flags & VFIO_IRQ_INFO_AUTOMASKED) {
+ disable_irq_nosync(irq_ctx->hwirq);
+ irq_ctx->masked = true;
+ }
+ }

- eventfd_signal(trigger, 1);
+ spin_unlock_irqrestore(&irq_ctx->lock, flags);

- return IRQ_HANDLED;
+ if (ret == IRQ_HANDLED)
+ eventfd_signal(irq_ctx->trigger, 1);
+
+ return ret;
}

static int vfio_set_trigger(struct vfio_platform_device *vdev,
@@ -159,6 +186,82 @@ static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev,
return -EFAULT;
}

+static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev,
+ unsigned index, unsigned start,
+ unsigned count, uint32_t flags, void *data)
+{
+ uint8_t arr;
+
+ if (start != 0 || count != 1)
+ return -EINVAL;
+
+ switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
+ case VFIO_IRQ_SET_DATA_BOOL:
+ if (copy_from_user(&arr, data, sizeof(uint8_t)))
+ return -EFAULT;
+
+ if (arr != 0x1)
+ return -EINVAL;
+
+ case VFIO_IRQ_SET_DATA_NONE:
+
+ spin_lock_irq(&vdev->irq[index].lock);
+
+ if (vdev->irq[index].masked) {
+ enable_irq(vdev->irq[index].hwirq);
+ vdev->irq[index].masked = false;
+ }
+
+ spin_unlock_irq(&vdev->irq[index].lock);
+
+ return 0;
+
+ case VFIO_IRQ_SET_DATA_EVENTFD: /* XXX not implemented yet */
+ default:
+ return -ENOTTY;
+ }
+
+ return 0;
+}
+
+static int vfio_platform_set_irq_mask(struct vfio_platform_device *vdev,
+ unsigned index, unsigned start,
+ unsigned count, uint32_t flags, void *data)
+{
+ uint8_t arr;
+
+ if (start != 0 || count != 1)
+ return -EINVAL;
+
+ switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
+ case VFIO_IRQ_SET_DATA_BOOL:
+ if (copy_from_user(&arr, data, sizeof(uint8_t)))
+ return -EFAULT;
+
+ if (arr != 0x1)
+ return -EINVAL;
+
+ case VFIO_IRQ_SET_DATA_NONE:
+
+ spin_lock_irq(&vdev->irq[index].lock);
+
+ if (!vdev->irq[index].masked) {
+ disable_irq(vdev->irq[index].hwirq);
+ vdev->irq[index].masked = true;
+ }
+
+ spin_unlock_irq(&vdev->irq[index].lock);
+
+ return 0;
+
+ case VFIO_IRQ_SET_DATA_EVENTFD: /* XXX not implemented yet */
+ default:
+ return -ENOTTY;
+ }
+
+ return 0;
+}
+
int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
uint32_t flags, unsigned index, unsigned start,
unsigned count, void *data)
@@ -169,8 +272,10 @@ int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,

switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
case VFIO_IRQ_SET_ACTION_MASK:
+ func = vfio_platform_set_irq_mask;
+ break;
case VFIO_IRQ_SET_ACTION_UNMASK:
- /* XXX not implemented */
+ func = vfio_platform_set_irq_unmask;
break;
case VFIO_IRQ_SET_ACTION_TRIGGER:
func = vfio_platform_set_irq_trigger;
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index befef01..5721313 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -21,6 +21,8 @@ struct vfio_platform_irq {
u32 count;
int hwirq;
char *name;
+ bool masked;
+ spinlock_t lock;
};

struct vfio_platform_region {
--
1.8.3.2