[RFC v5 06/13] VFIO: platform: add vfio_external_{mask|is_active|set_automasked}

From: Eric Auger
Date: Thu Mar 19 2015 - 11:02:28 EST


Introduces 3 new external functions aimed at doining some actions
on VFIO platform devices:
- mask a VFIO IRQ
- get the active status of a VFIO IRQ (active at interrupt
controller level or masked by the level-sensitive automasking).
- change the automasked property and the VFIO handler

Note there is no way to discriminate between user-space
masking and automasked handler masking. As a consequence, is_active
will return true in case the IRQ was masked by the user-space.

Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>

---

V4: creation
---
drivers/vfio/platform/vfio_platform_irq.c | 43 +++++++++++++++++++++++++++++++
include/linux/vfio.h | 14 ++++++++++
2 files changed, 57 insertions(+)

diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
index 8eb65c1..49994cb 100644
--- a/drivers/vfio/platform/vfio_platform_irq.c
+++ b/drivers/vfio/platform/vfio_platform_irq.c
@@ -231,6 +231,49 @@ static int vfio_set_trigger(struct vfio_platform_device *vdev, int index,
return 0;
}

+void vfio_external_mask(struct vfio_platform_device *vdev, int index)
+{
+ vfio_platform_mask(&vdev->irqs[index]);
+}
+EXPORT_SYMBOL_GPL(vfio_external_mask);
+
+bool vfio_external_is_active(struct vfio_platform_device *vdev, int index)
+{
+ unsigned long flags;
+ struct vfio_platform_irq *irq = &vdev->irqs[index];
+ bool active, masked, outstanding;
+ int ret;
+
+ spin_lock_irqsave(&irq->lock, flags);
+
+ ret = irq_get_irqchip_state(irq->hwirq, IRQCHIP_STATE_ACTIVE, &active);
+ BUG_ON(ret);
+ masked = irq->masked;
+ outstanding = active || masked;
+
+ spin_unlock_irqrestore(&irq->lock, flags);
+ return outstanding;
+}
+EXPORT_SYMBOL_GPL(vfio_external_is_active);
+
+void vfio_external_set_automasked(struct vfio_platform_device *vdev,
+ int index, bool automasked)
+{
+ unsigned long flags;
+ struct vfio_platform_irq *irq = &vdev->irqs[index];
+
+ spin_lock_irqsave(&irq->lock, flags);
+ if (automasked) {
+ irq->flags |= VFIO_IRQ_INFO_AUTOMASKED;
+ irq->handler = vfio_automasked_irq_handler;
+ } else {
+ irq->flags &= ~VFIO_IRQ_INFO_AUTOMASKED;
+ irq->handler = vfio_irq_handler;
+ }
+ spin_unlock_irqrestore(&irq->lock, flags);
+}
+EXPORT_SYMBOL_GPL(vfio_external_set_automasked);
+
static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev,
unsigned index, unsigned start,
unsigned count, uint32_t flags,
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index b18c38f..7aa6330 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -105,6 +105,20 @@ extern struct vfio_device *vfio_device_get_external_user(struct file *filep);
extern void vfio_device_put_external_user(struct vfio_device *vdev);
extern struct device *vfio_external_base_device(struct vfio_device *vdev);

+struct vfio_platform_device;
+extern void vfio_external_mask(struct vfio_platform_device *vdev, int index);
+/*
+ * returns whether the VFIO IRQ is active:
+ * true if not yet deactivated at interrupt controller level or if
+ * automasked (level sensitive IRQ). Unfortunately there is no way to
+ * discriminate between handler auto-masking and user-space masking
+ */
+extern bool vfio_external_is_active(struct vfio_platform_device *vdev,
+ int index);
+
+extern void vfio_external_set_automasked(struct vfio_platform_device *vdev,
+ int index, bool automasked);
+
struct pci_dev;
#ifdef CONFIG_EEH
extern void vfio_spapr_pci_eeh_open(struct pci_dev *pdev);
--
1.9.1

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