On Tue, 29 Sep 2020 12:03:37 +0300
Diana Craciun <diana.craciun@xxxxxxxxxxx> wrote:
> This patch allows to set an eventfd for fsl-mc device interrupts
> and also to trigger the interrupt eventfd from userspace for testing.
>
> All fsl-mc device interrupts are MSIs. The MSIs are allocated from
> the MSI domain only once per DPRC and used by all the DPAA2 objects.
> The interrupts are managed by the DPRC in a pool of interrupts. Each
> device requests interrupts from this pool. The pool is allocated
> when the first virtual device is setting the interrupts.
> The pool of interrupts is protected by a lock.
>
> The DPRC has an interrupt of its own which indicates if the DPRC
> contents have changed. However, currently, the contents of a DPRC
> assigned to the guest cannot be changed at runtime, so this interrupt
> is not configured.
>
> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@xxxxxxx>
> Signed-off-by: Diana Craciun <diana.craciun@xxxxxxxxxxx>
> ---
> drivers/vfio/fsl-mc/vfio_fsl_mc.c | 24 +++-
> drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c | 161 +++++++++++++++++++++-
> drivers/vfio/fsl-mc/vfio_fsl_mc_private.h | 10 ++
> 3 files changed, 193 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> index 2919e2d0041b..82157837f37a 100644
> --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> @@ -155,12 +155,34 @@ static int vfio_fsl_mc_open(void *device_data)
> static void vfio_fsl_mc_release(void *device_data)
> {
> struct vfio_fsl_mc_device *vdev = device_data;
> + int ret;
>
> mutex_lock(&vdev->reflck->lock);
>
> - if (!(--vdev->refcnt))
> + if (!(--vdev->refcnt)) {
> + struct fsl_mc_device *mc_dev = vdev->mc_dev;
> + struct device *cont_dev = fsl_mc_cont_dev(&mc_dev->dev);
> + struct fsl_mc_device *mc_cont = to_fsl_mc_device(cont_dev);
> +
> vfio_fsl_mc_regions_cleanup(vdev);
>
> + /* reset the device before cleaning up the interrupts */
> + ret = dprc_reset_container(mc_cont->mc_io, 0,
> + mc_cont->mc_handle,
> + mc_cont->obj_desc.id,
> + DPRC_RESET_OPTION_NON_RECURSIVE);
> +
> + if (ret) {
> + dev_warn(&mc_cont->dev, "VFIO_FLS_MC: reset device has failed (%d)\n",
> + ret);
> + WARN_ON(1);
> + }
> +
> + vfio_fsl_mc_irqs_cleanup(vdev);
> +
> + fsl_mc_cleanup_irq_pool(mc_cont);
> + }
> +
> mutex_unlock(&vdev->reflck->lock);
>
> module_put(THIS_MODULE);
> diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c b/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c
> index 5232f208e361..992ee18f1f6f 100644
> --- a/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c
> +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c
> @@ -13,12 +13,150 @@
> #include "linux/fsl/mc.h"
> #include "vfio_fsl_mc_private.h"
>
> +int vfio_fsl_mc_irqs_allocate(struct vfio_fsl_mc_device *vdev)
> +{
> + struct fsl_mc_device *mc_dev = vdev->mc_dev;
> + struct vfio_fsl_mc_irq *mc_irq;
> + int irq_count;
> + int ret, i;
> +
> + /* Device does not support any interrupt */
> + if (mc_dev->obj_desc.irq_count == 0)
> + return 0;
> +
> + /* interrupts were already allocated for this device */
> + if (vdev->mc_irqs)
> + return 0;
> +
> + irq_count = mc_dev->obj_desc.irq_count;
> +
> + mc_irq = kcalloc(irq_count, sizeof(*mc_irq), GFP_KERNEL);
> + if (!mc_irq)
> + return -ENOMEM;
> +
> + /* Allocate IRQs */
> + ret = fsl_mc_allocate_irqs(mc_dev);
> + if (ret) {
> + kfree(mc_irq);
> + return ret;
> + }
> +
> + for (i = 0; i < irq_count; i++) {
> + mc_irq[i].count = 1;
> + mc_irq[i].flags = VFIO_IRQ_INFO_EVENTFD;
> + }
> +
> + vdev->mc_irqs = mc_irq;
> +
> + return 0;
> +}
> +
> +static irqreturn_t vfio_fsl_mc_irq_handler(int irq_num, void *arg)
> +{
> + struct vfio_fsl_mc_irq *mc_irq = (struct vfio_fsl_mc_irq *)arg;
> +
> + eventfd_signal(mc_irq->trigger, 1);
> + return IRQ_HANDLED;
> +}
> +
> +static int vfio_set_trigger(struct vfio_fsl_mc_device *vdev,
> + int index, int fd)
> +{
> + struct vfio_fsl_mc_irq *irq = &vdev->mc_irqs[index];
> + struct eventfd_ctx *trigger;
> + int hwirq;
> + int ret;
> +
> + hwirq = vdev->mc_dev->irqs[index]->msi_desc->irq;
> + if (irq->trigger) {
> + free_irq(hwirq, irq);
> + kfree(irq->name);
> + eventfd_ctx_put(irq->trigger);
> + irq->trigger = NULL;
> + }
> +
> + if (fd < 0) /* Disable only */
> + return 0;
> +
> + irq->name = kasprintf(GFP_KERNEL, "vfio-irq[%d](%s)",
> + hwirq, dev_name(&vdev->mc_dev->dev));
> + if (!irq->name)
> + return -ENOMEM;
> +
> + trigger = eventfd_ctx_fdget(fd);
> + if (IS_ERR(trigger)) {
> + kfree(irq->name);
> + return PTR_ERR(trigger);
> + }
> +
> + irq->trigger = trigger;
> +
> + ret = request_irq(hwirq, vfio_fsl_mc_irq_handler, 0,
> + irq->name, irq);
> + if (ret) {
> + kfree(irq->name);
> + eventfd_ctx_put(trigger);
> + irq->trigger = NULL;
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> static int vfio_fsl_mc_set_irq_trigger(struct vfio_fsl_mc_device *vdev,
> unsigned int index, unsigned int start,
> unsigned int count, u32 flags,
> void *data)
> {
> - return -EINVAL;
> + struct fsl_mc_device *mc_dev = vdev->mc_dev;
> + int ret, hwirq;
> + struct vfio_fsl_mc_irq *irq;
> + struct device *cont_dev = fsl_mc_cont_dev(&mc_dev->dev);
> + struct fsl_mc_device *mc_cont = to_fsl_mc_device(cont_dev);
> +
> + if (start != 0 || count != 1)
> + return -EINVAL;
> +
> + mutex_lock(&vdev->reflck->lock);
> + ret = fsl_mc_populate_irq_pool(mc_cont,
> + FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS);
> + if (ret)
> + goto unlock;
> +
> + ret = vfio_fsl_mc_irqs_allocate(vdev);
> + if (ret)
> + goto unlock;
> + mutex_unlock(&vdev->reflck->lock);
> +
> + if (!count && (flags & VFIO_IRQ_SET_DATA_NONE))
> + return vfio_set_trigger(vdev, index, -1);
> +
> + if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
> + s32 fd = *(s32 *)data;
> +
> + return vfio_set_trigger(vdev, index, fd);
> + }
> +
> + hwirq = vdev->mc_dev->irqs[index]->msi_desc->irq;
> +
> + irq = &vdev->mc_irqs[index];
> +
> + if (flags & VFIO_IRQ_SET_DATA_NONE) {
> + vfio_fsl_mc_irq_handler(hwirq, irq);
> +
> + } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
> + u8 trigger = *(u8 *)data;
> +
> + if (trigger)
> + vfio_fsl_mc_irq_handler(hwirq, irq);
> + }
> +
> + return 0;
> +
> +unlock:
> + mutex_unlock(&vdev->reflck->lock);
> + return ret;
> +
> }
>
> int vfio_fsl_mc_set_irqs_ioctl(struct vfio_fsl_mc_device *vdev,
> @@ -32,3 +170,24 @@ int vfio_fsl_mc_set_irqs_ioctl(struct vfio_fsl_mc_device *vdev,
> else
> return -EINVAL;
> }
> +
> +/* Free All IRQs for the given MC object */
> +void vfio_fsl_mc_irqs_cleanup(struct vfio_fsl_mc_device *vdev)
> +{
> + struct fsl_mc_device *mc_dev = vdev->mc_dev;
> + int irq_count = mc_dev->obj_desc.irq_count;
> + int i;
> +
> + /* Device does not support any interrupt or the interrupts
> + * were not configured
> + */
> + if (mc_dev->obj_desc.irq_count == 0 || !vdev->mc_irqs)
Nit, the former test seems unnecessary, the latter test covers both
cases. Comment style also switched here. Thanks,
Alex
> + return;
> +
> + for (i = 0; i < irq_count; i++)
> + vfio_set_trigger(vdev, i, -1);
> +
> + fsl_mc_free_irqs(mc_dev);
> + kfree(vdev->mc_irqs);
> + vdev->mc_irqs = NULL;
> +}
> diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
> index 2c3f625a3240..7aa49b9ba60d 100644
> --- a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
> +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
> @@ -15,6 +15,13 @@
> #define VFIO_FSL_MC_INDEX_TO_OFFSET(index) \
> ((u64)(index) << VFIO_FSL_MC_OFFSET_SHIFT)
>
> +struct vfio_fsl_mc_irq {
> + u32 flags;
> + u32 count;
> + struct eventfd_ctx *trigger;
> + char *name;
> +};
> +
> struct vfio_fsl_mc_reflck {
> struct kref kref;
> struct mutex lock;
> @@ -34,6 +41,7 @@ struct vfio_fsl_mc_device {
> struct vfio_fsl_mc_region *regions;
> struct vfio_fsl_mc_reflck *reflck;
> struct mutex igate;
> + struct vfio_fsl_mc_irq *mc_irqs;
> };
>
> extern int vfio_fsl_mc_set_irqs_ioctl(struct vfio_fsl_mc_device *vdev,
> @@ -41,4 +49,6 @@ extern int vfio_fsl_mc_set_irqs_ioctl(struct vfio_fsl_mc_device *vdev,
> unsigned int start, unsigned int count,
> void *data);
>
> +void vfio_fsl_mc_irqs_cleanup(struct vfio_fsl_mc_device *vdev);
> +
> #endif /* VFIO_FSL_MC_PRIVATE_H */
