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@xxxxxxxxxxxxxxxxxxxxxx>
---
drivers/vfio/platform/vfio_platform_irq.c | 120 ++++++++++++++++++++++++--
drivers/vfio/platform/vfio_platform_private.h | 2 +
2 files changed, 117 insertions(+), 5 deletions(-)
diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
index 25a7825..90fa25a 100644
--- a/drivers/vfio/platform/vfio_platform_irq.c
+++ b/drivers/vfio/platform/vfio_platform_irq.c
@@ -31,27 +31,129 @@
#include "vfio_platform_private.h"
+static void vfio_platform_mask(struct vfio_platform_irq *irq_ctx)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&irq_ctx->lock, flags);
+
+ if (!irq_ctx->masked) {
+ disable_irq(irq_ctx->hwirq);
+ irq_ctx->masked = true;
+ }
+
+ spin_unlock_irqrestore(&irq_ctx->lock, flags);
+}
+
static int vfio_platform_set_irq_mask(struct vfio_platform_device *vdev,
unsigned index, unsigned start,
unsigned count, uint32_t flags, void *data)
{
- return -EINVAL;
+ uint8_t irq_bitmap;
+
+ 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(&irq_bitmap, data, sizeof(uint8_t)))
+ return -EFAULT;
+
+ if (irq_bitmap != 0x1)
+ return -EINVAL;
+
+ /*
+ * The following fall through is both intentional and safe.
+ * VFIO_IRQ_SET_DATA_BOOL allows to handle an array of IRQs
+ * on the same index. For VFIO platform devices we always have
+ * one IRQ per index, so as soon as we check that the user
+ * provided bitmap only refers to one single IRQ, we can safely
+ * share the rest of the logic with VFIO_IRQ_SET_DATA_NONE.
+ */
+
+ case VFIO_IRQ_SET_DATA_NONE:
+ vfio_platform_mask(&vdev->irqs[index]);
+ return 0;
+
+ case VFIO_IRQ_SET_DATA_EVENTFD: /* XXX not implemented yet */
+ default:
+ return -ENOTTY;
+ }
+
+ return 0;
+}
+
+static void vfio_platform_unmask(struct vfio_platform_irq *irq_ctx)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&irq_ctx->lock, flags);
+
+ if (irq_ctx->masked) {
+ enable_irq(irq_ctx->hwirq);
+ irq_ctx->masked = false;
+ }
+
+ spin_unlock_irqrestore(&irq_ctx->lock, flags);
}
static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev,
unsigned index, unsigned start,
unsigned count, uint32_t flags, void *data)
{
- return -EINVAL;
+ uint8_t irq_bitmap;
+
+ 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(&irq_bitmap, data, sizeof(uint8_t)))
+ return -EFAULT;
+
+ if (irq_bitmap != 0x1)
+ return -EINVAL;
+
+ /*
+ * The following fall through is both intentional and safe,
+ * as in vfio_platform_set_irq_mask().
+ */
+
+ case VFIO_IRQ_SET_DATA_NONE:
+ vfio_platform_unmask(&vdev->irqs[index]);
+ return 0;
+
+ case VFIO_IRQ_SET_DATA_EVENTFD: /* XXX not implemented yet */
+ default:
+ return -ENOTTY;
+ }
+
+ return 0;
}
static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
{
struct vfio_platform_irq *irq_ctx = dev_id;
+ unsigned long flags;
+ int ret = IRQ_NONE;
- eventfd_signal(irq_ctx->trigger, 1);
+ spin_lock_irqsave(&irq_ctx->lock, flags);
- return IRQ_HANDLED;
+ 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;
+ }
+ }
+
+ spin_unlock_irqrestore(&irq_ctx->lock, flags);
+
+ if (ret == IRQ_HANDLED)
+ eventfd_signal(irq_ctx->trigger, 1);
+
+ return ret;
}
static int vfio_set_trigger(struct vfio_platform_device *vdev,
@@ -175,9 +277,17 @@ int vfio_platform_irq_init(struct vfio_platform_device *vdev)
if (hwirq < 0)
goto err;
- vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD;
+ spin_lock_init(&vdev->irqs[i].lock);
+
+ vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD
+ | VFIO_IRQ_INFO_MASKABLE;
+
+ if (irq_get_trigger_type(hwirq) & IRQ_TYPE_LEVEL_MASK)
+ vdev->irqs[i].flags |= VFIO_IRQ_INFO_AUTOMASKED;
+
vdev->irqs[i].count = 1;
vdev->irqs[i].hwirq = hwirq;
+ vdev->irqs[i].masked = false;
}
vdev->num_irqs = cnt;
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index 765b371..500e299 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -30,6 +30,8 @@ struct vfio_platform_irq {
int hwirq;
char *name;
struct eventfd_ctx *trigger;
+ bool masked;
+ spinlock_t lock;
};
struct vfio_platform_region {
--
1.8.3.2
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