On 08/27/2013 05:59 PM, Philip J. Kelleher wrote:
> diff -uprN -X linux-block-vanilla/Documentation/dontdiff
> linux-block-vanilla/drivers/block/rsxx/dma.c
> linux-block/drivers/block/rsxx/dma.c
> --- linux-block-vanilla/drivers/block/rsxx/dma.c 2013-08-12
> 15:22:18.612863489 -0500
> +++ linux-block/drivers/block/rsxx/dma.c 2013-08-12 15:23:22.158858765
> -0500
> @@ -433,6 +434,27 @@ static void rsxx_issue_dmas(struct rsxx_
> continue;
> }
>
> + if (dma->cmd == HW_CMD_BLK_WRITE)
> + dir = PCI_DMA_TODEVICE;
> + else
> + dir = PCI_DMA_FROMDEVICE;
> +
> + /*
> + * The function pci_map_page is placed here because we can
> + * only, by design, issue up to 255 commands to the hardware
> + * at one time per DMA channel. So the maximum amount of mapped
> + * memory would be 255 * 4 channels * 4096 Bytes which is less
> + * than 2GB, the limit of a x8 Non-HWWD PCIe slot. This way the
> + * pci_map_page function should never fail because of a
> + * lack of mappable memory.
> + */
> + dma->dma_addr = pci_map_page(ctrl->card->dev, dma->page,
> + dma->pg_off, dma->sub_page.cnt << 9, dir);
> + if (pci_dma_mapping_error(ctrl->card->dev, dma->dma_addr)) {
Do you also need to do a push_tracker here as well so you don't leak a tag?
Why is this error case handled different compared to the dma_fault case earlier
in this same function?
> + kmem_cache_free(rsxx_dma_pool, dma);
> + return;
> + }
> +
> set_tracker_dma(ctrl->trackers, tag, dma);
> hw_cmd_buf[ctrl->cmd.idx].command = dma->cmd;
> hw_cmd_buf[ctrl->cmd.idx].tag = tag;
-Brian
--
Brian King
Power Linux I/O
IBM Linux Technology Center
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
