[PATCH v2 1/8] VFIO: platform: Differentiate auto-masking from user masking

Eric Auger
2017-06-15T12:49:45Z

For direct EOI modality we will need to differentiate a userspace
masking from the IRQ handler auto-masking.

The level sensitive IRQ handler sets the automasked flag while
VFIO_DEVICE_SET_IRQS with VFIO_IRQ_SET_ACTION_MASK sets the
usermasked flag. VFIO_IRQ_SET_ACTION_UNMASK resets both flags.

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

---

v1 -> v2:
- rename maked into usermasked
- add is_masked() macro
- commit message reworded to better explain role of each flag
- change commit title
---
drivers/vfio/platform/vfio_platform_irq.c | 18 ++++++++++--------
drivers/vfio/platform/vfio_platform_private.h | 6 +++++-
2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
index 46d4750..6740dbe 100644
--- a/drivers/vfio/platform/vfio_platform_irq.c
+++ b/drivers/vfio/platform/vfio_platform_irq.c
@@ -29,9 +29,9 @@ static void vfio_platform_mask(struct vfio_platform_irq *irq_ctx)

spin_lock_irqsave(&irq_ctx->lock, flags);

- if (!irq_ctx->masked) {
+ if (!is_masked(irq_ctx)) {
disable_irq_nosync(irq_ctx->hwirq);
- irq_ctx->masked = true;
+ irq_ctx->usermasked = true;
}

spin_unlock_irqrestore(&irq_ctx->lock, flags);
@@ -89,9 +89,10 @@ static void vfio_platform_unmask(struct vfio_platform_irq *irq_ctx)

spin_lock_irqsave(&irq_ctx->lock, flags);

- if (irq_ctx->masked) {
+ if (is_masked(irq_ctx)) {
enable_irq(irq_ctx->hwirq);
- irq_ctx->masked = false;
+ irq_ctx->usermasked = false;
+ irq_ctx->automasked = false;
}

spin_unlock_irqrestore(&irq_ctx->lock, flags);
@@ -152,12 +153,12 @@ static irqreturn_t vfio_automasked_irq_handler(int irq, void *dev_id)

spin_lock_irqsave(&irq_ctx->lock, flags);

- if (!irq_ctx->masked) {
+ if (!is_masked(irq_ctx)) {
ret = IRQ_HANDLED;

/* automask maskable interrupts */
disable_irq_nosync(irq_ctx->hwirq);
- irq_ctx->masked = true;
+ irq_ctx->automasked = true;
}

spin_unlock_irqrestore(&irq_ctx->lock, flags);
@@ -217,7 +218,7 @@ static int vfio_set_trigger(struct vfio_platform_device *vdev, int index,
return ret;
}

- if (!irq->masked)
+ if (!irq->usermasked)
enable_irq(irq->hwirq);

return 0;
@@ -314,7 +315,8 @@ int vfio_platform_irq_init(struct vfio_platform_device *vdev)

vdev->irqs[i].count = 1;
vdev->irqs[i].hwirq = hwirq;
- vdev->irqs[i].masked = false;
+ vdev->irqs[i].usermasked = false;
+ vdev->irqs[i].automasked = false;
}

vdev->num_irqs = cnt;
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index 85ffe5d..e8db291 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -33,7 +33,8 @@ struct vfio_platform_irq {
int hwirq;
char *name;
struct eventfd_ctx *trigger;
- bool masked;
+ bool usermasked;
+ bool automasked;
spinlock_t lock;
struct virqfd *unmask;
struct virqfd *mask;
@@ -102,6 +103,9 @@ extern int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
extern void __vfio_platform_register_reset(struct vfio_platform_reset_node *n);
extern void vfio_platform_unregister_reset(const char *compat,
vfio_platform_reset_fn_t fn);
+
+#define is_masked(irq) ((irq)->usermasked || (irq)->automasked)
+
#define vfio_platform_register_reset(__compat, __reset) \
static struct vfio_platform_reset_node __reset ## _node = { \
.owner = THIS_MODULE, \
--
2.5.5