On 05-08-21, 15:10, Arnd Bergmann wrote:
> I hope this can still be simplified by working out better which state
> transitions are needed exactly. In particular, I would expect that we
> can get away with not sending a VIRTIO_GPIO_MSG_IRQ_TYPE
> for 'mask' state changes at all, but use that only for forcing 'enabled'
> state changes.
Something like this ?
struct vgpio_irq_line {
u8 type;
bool masked;
bool update_pending;
bool queued;
struct virtio_gpio_irq_request ireq ____cacheline_aligned;
struct virtio_gpio_irq_response ires ____cacheline_aligned;
};
static void virtio_gpio_irq_disable(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct virtio_gpio *vgpio = gpiochip_get_data(gc);
struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq];
irq_line->masked = true;
irq_line->update_pending = true;
}
static void virtio_gpio_irq_enable(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct virtio_gpio *vgpio = gpiochip_get_data(gc);
struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq];
irq_line->masked = false;
irq_line->update_pending = true;
/* Queue the buffer unconditionally on enable */
virtio_gpio_irq_prepare(vgpio, d->hwirq);
}
static void virtio_gpio_irq_mask(struct irq_data *d)
{
/* Nothing to do here */
}
static void virtio_gpio_irq_unmask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct virtio_gpio *vgpio = gpiochip_get_data(gc);
/* Queue the buffer unconditionally on unmask */
virtio_gpio_irq_prepare(vgpio, d->hwirq);
}
static int virtio_gpio_irq_set_type(struct irq_data *d, unsigned int type)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct virtio_gpio *vgpio = gpiochip_get_data(gc);
struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq];
switch (type) {
case IRQ_TYPE_NONE:
type = VIRTIO_GPIO_IRQ_TYPE_NONE;
break;
case IRQ_TYPE_EDGE_RISING:
type = VIRTIO_GPIO_IRQ_TYPE_EDGE_RISING;
break;
case IRQ_TYPE_EDGE_FALLING:
type = VIRTIO_GPIO_IRQ_TYPE_EDGE_FALLING;
break;
case IRQ_TYPE_EDGE_BOTH:
type = VIRTIO_GPIO_IRQ_TYPE_EDGE_BOTH;
break;
case IRQ_TYPE_LEVEL_LOW:
type = VIRTIO_GPIO_IRQ_TYPE_LEVEL_LOW;
break;
case IRQ_TYPE_LEVEL_HIGH:
type = VIRTIO_GPIO_IRQ_TYPE_LEVEL_HIGH;
break;
default:
dev_err(&vgpio->vdev->dev, "unsupported irq type: %u\n", type);
return -EINVAL;
}
irq_line->type = type;
irq_line->update_pending = true;
return 0;
}
static void update_irq_type(struct virtio_gpio *vgpio, u16 gpio, u8 type)
{
virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_IRQ_TYPE, gpio, type, NULL);
}
static void virtio_gpio_irq_bus_lock(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct virtio_gpio *vgpio = gpiochip_get_data(gc);
mutex_lock(&vgpio->irq_lock);
}
static void virtio_gpio_irq_bus_sync_unlock(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct virtio_gpio *vgpio = gpiochip_get_data(gc);
struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq];
u8 type = irq_line->masked ? VIRTIO_GPIO_IRQ_TYPE_NONE : irq_line->type;
if (irq_line->update_pending) {
irq_line->update_pending = false;
update_irq_type(vgpio, d->hwirq, type);
}
mutex_unlock(&vgpio->irq_lock);
}
static struct irq_chip vgpio_irq_chip = {
.name = "virtio-gpio",
.irq_enable = virtio_gpio_irq_enable,
.irq_disable = virtio_gpio_irq_disable,
.irq_mask = virtio_gpio_irq_mask,
.irq_unmask = virtio_gpio_irq_unmask,
.irq_set_type = virtio_gpio_irq_set_type,
/* These are required to implement irqchip for slow busses */
.irq_bus_lock = virtio_gpio_irq_bus_lock,
.irq_bus_sync_unlock = virtio_gpio_irq_bus_sync_unlock,
};
> One part that I think is missing though is remembering the case
> when an eventq message came in after an interrupt got masked
> when the message was already armed. In this case, the
> virtio_gpio_event_vq() function would not call the irq handler,
> but the subsequent "unmask" callback would need to arrange
> having it called.
I will come back to this.
--
viresh
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