From: Dave Jiang
> Adding support on the rx DMA path to allow recovery of errors when
> DMA responds with error status and abort all the subsequent ops.
>
> Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
> Cc: Allen Hubbe <Allen.Hubbe@xxxxxxx>
> Cc: Jon Mason <jdmason@xxxxxxxx>
> Cc: linux-ntb@xxxxxxxxxxxxxxxx
Acked-by: Allen Hubbe <Allen.Hubbe@xxxxxxx>
> ---
> drivers/ntb/ntb_transport.c | 83 +++++++++++++++++++++++++++++++++++--------
> 1 file changed, 67 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
> index 01da764..d825712 100644
> --- a/drivers/ntb/ntb_transport.c
> +++ b/drivers/ntb/ntb_transport.c
> @@ -105,13 +105,13 @@ struct ntb_queue_entry {
> int retries;
> int errors;
> unsigned int tx_index;
> + unsigned int rx_index;
>
> struct ntb_transport_qp *qp;
> union {
> struct ntb_payload_header __iomem *tx_hdr;
> struct ntb_payload_header *rx_hdr;
> };
> - unsigned int index;
> };
>
> struct ntb_rx_info {
> @@ -264,6 +264,9 @@ static struct ntb_client ntb_transport_client;
> static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
> struct ntb_queue_entry *entry);
> static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset);
> +static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset);
> +static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset);
> +
>
> static int ntb_transport_bus_match(struct device *dev,
> struct device_driver *drv)
> @@ -1207,7 +1210,7 @@ static void ntb_complete_rxc(struct ntb_transport_qp *qp)
> break;
>
> entry->rx_hdr->flags = 0;
> - iowrite32(entry->index, &qp->rx_info->entry);
> + iowrite32(entry->rx_index, &qp->rx_info->entry);
>
> cb_data = entry->cb_data;
> len = entry->len;
> @@ -1225,10 +1228,36 @@ static void ntb_complete_rxc(struct ntb_transport_qp *qp)
> spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
> }
>
> -static void ntb_rx_copy_callback(void *data)
> +static void ntb_rx_copy_callback(void *data,
> + const struct dmaengine_result *res)
> {
> struct ntb_queue_entry *entry = data;
>
> + /* we need to check DMA results if we are using DMA */
> + if (res) {
> + enum dmaengine_tx_result dma_err = res->result;
> +
> + switch (dma_err) {
> + case DMA_TRANS_READ_FAILED:
> + case DMA_TRANS_WRITE_FAILED:
> + entry->errors++;
> + case DMA_TRANS_ABORTED:
> + {
> + struct ntb_transport_qp *qp = entry->qp;
> + void *offset = qp->rx_buff + qp->rx_max_frame *
> + qp->rx_index;
> +
> + ntb_memcpy_rx(entry, offset);
> + qp->rx_memcpy++;
> + return;
> + }
> +
> + case DMA_TRANS_NOERROR:
> + default:
> + break;
> + }
> + }
> +
> entry->flags |= DESC_DONE_FLAG;
>
> ntb_complete_rxc(entry->qp);
> @@ -1244,10 +1273,10 @@ static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void
> *offset)
> /* Ensure that the data is fully copied out before clearing the flag */
> wmb();
>
> - ntb_rx_copy_callback(entry);
> + ntb_rx_copy_callback(entry, NULL);
> }
>
> -static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
> +static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
> {
> struct dma_async_tx_descriptor *txd;
> struct ntb_transport_qp *qp = entry->qp;
> @@ -1260,13 +1289,6 @@ static void ntb_async_rx(struct ntb_queue_entry *entry, void
> *offset)
> int retries = 0;
>
> len = entry->len;
> -
> - if (!chan)
> - goto err;
> -
> - if (len < copy_bytes)
> - goto err;
> -
> device = chan->device;
> pay_off = (size_t)offset & ~PAGE_MASK;
> buff_off = (size_t)buf & ~PAGE_MASK;
> @@ -1294,7 +1316,8 @@ static void ntb_async_rx(struct ntb_queue_entry *entry, void
> *offset)
> unmap->from_cnt = 1;
>
> for (retries = 0; retries < DMA_RETRIES; retries++) {
> - txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
> + txd = device->device_prep_dma_memcpy(chan,
> + unmap->addr[1],
> unmap->addr[0], len,
> DMA_PREP_INTERRUPT);
> if (txd)
> @@ -1309,7 +1332,7 @@ static void ntb_async_rx(struct ntb_queue_entry *entry, void
> *offset)
> goto err_get_unmap;
> }
>
> - txd->callback = ntb_rx_copy_callback;
> + txd->callback_result = ntb_rx_copy_callback;
> txd->callback_param = entry;
> dma_set_unmap(txd, unmap);
>
> @@ -1323,13 +1346,38 @@ static void ntb_async_rx(struct ntb_queue_entry *entry, void
> *offset)
>
> qp->rx_async++;
>
> - return;
> + return 0;
>
> err_set_unmap:
> dmaengine_unmap_put(unmap);
> err_get_unmap:
> dmaengine_unmap_put(unmap);
> err:
> + return -ENXIO;
> +}
> +
> +static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
> +{
> + struct ntb_transport_qp *qp = entry->qp;
> + struct dma_chan *chan = qp->rx_dma_chan;
> + int res;
> +
> + if (!chan)
> + goto err;
> +
> + if (entry->len < copy_bytes)
> + goto err;
> +
> + res = ntb_async_rx_submit(entry, offset);
> + if (res < 0)
> + goto err;
> +
> + if (!entry->retries)
> + qp->rx_async++;
> +
> + return;
> +
> +err:
> ntb_memcpy_rx(entry, offset);
> qp->rx_memcpy++;
> }
> @@ -1375,7 +1423,7 @@ static int ntb_process_rxc(struct ntb_transport_qp *qp)
> }
>
> entry->rx_hdr = hdr;
> - entry->index = qp->rx_index;
> + entry->rx_index = qp->rx_index;
>
> if (hdr->len > entry->len) {
> dev_dbg(&qp->ndev->pdev->dev,
> @@ -1951,6 +1999,9 @@ int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb,
> void *data,
> entry->buf = data;
> entry->len = len;
> entry->flags = 0;
> + entry->retries = 0;
> + entry->errors = 0;
> + entry->rx_index = 0;
>
> ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
>
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