On 8/21/25 3:59 PM, Vinicius Costa Gomes wrote:
> When a Function Level Reset (FLR) happens, terminate the pending
> descriptors that were issued by in-kernel users and disable the
> interrupts associated with those. They will be re-enabled after FLR
> finishes.
>
> idxd_wq_flush_desc() is declared on idxd.h because it's going to be
> used in by the DMA backend in a future patch.
>
> Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
> drivers/dma/idxd/device.c | 20 ++++++++++++++++++++
> drivers/dma/idxd/idxd.h | 1 +
> drivers/dma/idxd/irq.c | 16 ++++++++++++++++
> 3 files changed, 37 insertions(+)
>
> diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
> index 02bda8868e24..c62808e30417 100644
> --- a/drivers/dma/idxd/device.c
> +++ b/drivers/dma/idxd/device.c
> @@ -1319,6 +1319,11 @@ void idxd_wq_free_irq(struct idxd_wq *wq)
>
> free_irq(ie->vector, ie);
> idxd_flush_pending_descs(ie);
> +
> + /* The interrupt might have been already released by FLR */
> + if (ie->int_handle == INVALID_INT_HANDLE)
> + return;
> +
> if (idxd->request_int_handles)
> idxd_device_release_int_handle(idxd, ie->int_handle, IDXD_IRQ_MSIX);
> idxd_device_clear_perm_entry(idxd, ie);
> @@ -1327,6 +1332,21 @@ void idxd_wq_free_irq(struct idxd_wq *wq)
> ie->pasid = IOMMU_PASID_INVALID;
> }
>
> +void idxd_wq_flush_descs(struct idxd_wq *wq)
> +{
> + struct idxd_irq_entry *ie = &wq->ie;
> + struct idxd_device *idxd = wq->idxd;
> +
> + if (wq->state != IDXD_WQ_ENABLED || wq->type != IDXD_WQT_KERNEL)
> + return;
> +
> + idxd_flush_pending_descs(ie);
> + if (idxd->request_int_handles)
> + idxd_device_release_int_handle(idxd, ie->int_handle, IDXD_IRQ_MSIX);
> + idxd_device_clear_perm_entry(idxd, ie);
> + ie->int_handle = INVALID_INT_HANDLE;
> +}
> +
> int idxd_wq_request_irq(struct idxd_wq *wq)
> {
> struct idxd_device *idxd = wq->idxd;
> diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
> index 74e6695881e6..fb7f570e002b 100644
> --- a/drivers/dma/idxd/idxd.h
> +++ b/drivers/dma/idxd/idxd.h
> @@ -784,6 +784,7 @@ void idxd_wq_quiesce(struct idxd_wq *wq);
> int idxd_wq_init_percpu_ref(struct idxd_wq *wq);
> void idxd_wq_free_irq(struct idxd_wq *wq);
> int idxd_wq_request_irq(struct idxd_wq *wq);
> +void idxd_wq_flush_descs(struct idxd_wq *wq);
>
> /* submission */
> int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc);
> diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c
> index 1107db3ce0a3..8d0eaf5029fa 100644
> --- a/drivers/dma/idxd/irq.c
> +++ b/drivers/dma/idxd/irq.c
> @@ -397,6 +397,17 @@ static void idxd_device_flr(struct work_struct *work)
> dev_err(&idxd->pdev->dev, "FLR failed\n");
> }
>
> +static void idxd_wqs_flush_descs(struct idxd_device *idxd)
> +{
> + int i;
> +
> + for (i = 0; i < idxd->max_wqs; i++) {
> + struct idxd_wq *wq = idxd->wqs[i];
> +
> + idxd_wq_flush_descs(wq);
> + }
> +}
> +
> static irqreturn_t idxd_halt(struct idxd_device *idxd)
> {
> union gensts_reg gensts;
> @@ -415,6 +426,11 @@ static irqreturn_t idxd_halt(struct idxd_device *idxd)
> } else if (gensts.reset_type == IDXD_DEVICE_RESET_FLR) {
> idxd->state = IDXD_DEV_HALTED;
> idxd_mask_error_interrupts(idxd);
> + /* Flush all pending descriptors, and disable
> + * interrupts, they will be re-enabled when FLR
> + * concludes.
> + */
> + idxd_wqs_flush_descs(idxd);
> dev_dbg(&idxd->pdev->dev,
> "idxd halted, doing FLR. After FLR, configs are restored\n");
> INIT_WORK(&idxd->work, idxd_device_flr);
>