[RFC 02/17] VFIO: platform: single handler using function pointer

Eric Auger
2015-07-02T13:18:18Z

A single handler now is registered whatever the use case: automasked
or not. A function pointer is set according to the wished behavior
and the handler calls this function.

The irq lock is taken/released in the root handler. eventfd_signal can
be called in regions not allowed to sleep.

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

---

v4: creation
---
drivers/vfio/platform/vfio_platform_irq.c | 21 +++++++++++++++------
drivers/vfio/platform/vfio_platform_private.h | 1 +
2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
index 132bb3f..8eb65c1 100644
--- a/drivers/vfio/platform/vfio_platform_irq.c
+++ b/drivers/vfio/platform/vfio_platform_irq.c
@@ -147,11 +147,8 @@ static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev,
static irqreturn_t vfio_automasked_irq_handler(int irq, void *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;

@@ -160,8 +157,6 @@ static irqreturn_t vfio_automasked_irq_handler(int irq, void *dev_id)
irq_ctx->masked = true;
}

- spin_unlock_irqrestore(&irq_ctx->lock, flags);
-
if (ret == IRQ_HANDLED)
eventfd_signal(irq_ctx->trigger, 1);

@@ -177,6 +172,19 @@ static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
return IRQ_HANDLED;
}

+static irqreturn_t vfio_handler(int irq, void *dev_id)
+{
+ struct vfio_platform_irq *irq_ctx = dev_id;
+ unsigned long flags;
+ irqreturn_t ret;
+
+ spin_lock_irqsave(&irq_ctx->lock, flags);
+ ret = irq_ctx->handler(irq, dev_id);
+ spin_unlock_irqrestore(&irq_ctx->lock, flags);
+
+ return ret;
+}
+
static int vfio_set_trigger(struct vfio_platform_device *vdev, int index,
int fd, irq_handler_t handler)
{
@@ -206,9 +214,10 @@ static int vfio_set_trigger(struct vfio_platform_device *vdev, int index,
}

irq->trigger = trigger;
+ irq->handler = handler;

irq_set_status_flags(irq->hwirq, IRQ_NOAUTOEN);
- ret = request_irq(irq->hwirq, handler, 0, irq->name, irq);
+ ret = request_irq(irq->hwirq, vfio_handler, 0, irq->name, irq);
if (ret) {
kfree(irq->name);
eventfd_ctx_put(trigger);
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index 1c9b3d5..413f575 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -37,6 +37,7 @@ struct vfio_platform_irq {
spinlock_t lock;
struct virqfd *unmask;
struct virqfd *mask;
+ irqreturn_t (*handler)(int irq, void *dev_id);
};

struct vfio_platform_region {
--
1.9.1