From: Dave Jiang
> Adding support on the tx 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 | 110 ++++++++++++++++++++++++++++++++-----------
> 1 file changed, 83 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
> index 2ef9d913..01da764 100644
> --- a/drivers/ntb/ntb_transport.c
> +++ b/drivers/ntb/ntb_transport.c
> @@ -102,6 +102,9 @@ struct ntb_queue_entry {
> void *buf;
> unsigned int len;
> unsigned int flags;
> + int retries;
> + int errors;
> + unsigned int tx_index;
>
> struct ntb_transport_qp *qp;
> union {
> @@ -258,6 +261,9 @@ enum {
> static void ntb_transport_rxc_db(unsigned long data);
> static const struct ntb_ctx_ops ntb_transport_ops;
> 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_transport_bus_match(struct device *dev,
> struct device_driver *drv)
> @@ -1439,12 +1445,39 @@ static void ntb_transport_rxc_db(unsigned long data)
> }
> }
>
> -static void ntb_tx_copy_callback(void *data)
> +static void ntb_tx_copy_callback(void *data,
> + const struct dmaengine_result *res)
> {
> struct ntb_queue_entry *entry = data;
> struct ntb_transport_qp *qp = entry->qp;
> struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
>
> + /* 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:
> + {
> + void __iomem *offset =
> + qp->tx_mw + qp->tx_max_frame *
> + entry->tx_index;
> +
> + /* resubmit via CPU */
> + ntb_memcpy_tx(entry, offset);
> + qp->tx_memcpy++;
> + return;
> + }
> +
> + case DMA_TRANS_NOERROR:
> + default:
> + break;
> + }
> + }
> +
> iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
>
> ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
> @@ -1479,40 +1512,25 @@ static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void
> __iomem *offset)
> /* Ensure that the data is fully copied out before setting the flags */
> wmb();
>
> - ntb_tx_copy_callback(entry);
> + ntb_tx_copy_callback(entry, NULL);
> }
>
> -static void ntb_async_tx(struct ntb_transport_qp *qp,
> - struct ntb_queue_entry *entry)
> +static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
> + struct ntb_queue_entry *entry)
> {
> - struct ntb_payload_header __iomem *hdr;
> struct dma_async_tx_descriptor *txd;
> struct dma_chan *chan = qp->tx_dma_chan;
> struct dma_device *device;
> + size_t len = entry->len;
> + void *buf = entry->buf;
> size_t dest_off, buff_off;
> struct dmaengine_unmap_data *unmap;
> dma_addr_t dest;
> dma_cookie_t cookie;
> - void __iomem *offset;
> - size_t len = entry->len;
> - void *buf = entry->buf;
> int retries = 0;
>
> - offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
> - hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
> - entry->tx_hdr = hdr;
> -
> - iowrite32(entry->len, &hdr->len);
> - iowrite32((u32)qp->tx_pkts, &hdr->ver);
> -
> - if (!chan)
> - goto err;
> -
> - if (len < copy_bytes)
> - goto err;
> -
> device = chan->device;
> - dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index;
> + dest = qp->tx_mw_phys + qp->tx_max_frame * entry->tx_index;
> buff_off = (size_t)buf & ~PAGE_MASK;
> dest_off = (size_t)dest & ~PAGE_MASK;
>
> @@ -1532,8 +1550,9 @@ static void ntb_async_tx(struct ntb_transport_qp *qp,
> unmap->to_cnt = 1;
>
> for (retries = 0; retries < DMA_RETRIES; retries++) {
> - txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0],
> - len, DMA_PREP_INTERRUPT);
> + txd = device->device_prep_dma_memcpy(chan, dest,
> + unmap->addr[0], len,
> + DMA_PREP_INTERRUPT);
> if (txd)
> break;
>
> @@ -1546,7 +1565,7 @@ static void ntb_async_tx(struct ntb_transport_qp *qp,
> goto err_get_unmap;
> }
>
> - txd->callback = ntb_tx_copy_callback;
> + txd->callback_result = ntb_tx_copy_callback;
> txd->callback_param = entry;
> dma_set_unmap(txd, unmap);
>
> @@ -1557,14 +1576,48 @@ static void ntb_async_tx(struct ntb_transport_qp *qp,
> dmaengine_unmap_put(unmap);
>
> dma_async_issue_pending(chan);
> - qp->tx_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_tx(struct ntb_transport_qp *qp,
> + struct ntb_queue_entry *entry)
> +{
> + struct ntb_payload_header __iomem *hdr;
> + struct dma_chan *chan = qp->tx_dma_chan;
> + void __iomem *offset;
> + int res;
> +
> + entry->tx_index = qp->tx_index;
> + offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
> + hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
> + entry->tx_hdr = hdr;
> +
> + iowrite32(entry->len, &hdr->len);
> + iowrite32((u32)qp->tx_pkts, &hdr->ver);
> +
> + if (!chan)
> + goto err;
> +
> + if (entry->len < copy_bytes)
> + goto err;
> +
> + res = ntb_async_tx_submit(qp, entry);
> + if (res < 0)
> + goto err;
> +
> + if (!entry->retries)
> + qp->tx_async++;
> +
> + return;
> +
> +err:
> ntb_memcpy_tx(entry, offset);
> qp->tx_memcpy++;
> }
> @@ -1940,6 +1993,9 @@ int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb,
> void *data,
> entry->buf = data;
> entry->len = len;
> entry->flags = 0;
> + entry->errors = 0;
> + entry->retries = 0;
> + entry->tx_index = 0;
>
> rc = ntb_process_tx(qp, entry);
> if (rc)
--
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