diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/ntb/ntb_transport.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index 7a765d3230d8..e07b056af3be 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -88,6 +88,10 @@ static unsigned int copy_bytes = 1024; module_param(copy_bytes, uint, 0644); MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA"); +static bool use_dma; +module_param(use_dma, bool, 0644); +MODULE_PARM_DESC(use_dma, "Use DMA engine to perform large data copy"); + static struct dentry *nt_debugfs_dir; struct ntb_queue_entry { @@ -1589,10 +1593,15 @@ ntb_transport_create_queue(void *data, struct device *client_dev, dma_cap_zero(dma_mask); dma_cap_set(DMA_MEMCPY, dma_mask); - qp->dma_chan = dma_request_channel(dma_mask, ntb_dma_filter_fn, - (void *)(unsigned long)node); - if (!qp->dma_chan) - dev_info(&pdev->dev, "Unable to allocate DMA channel, using CPU instead\n"); + if (use_dma) { + qp->dma_chan = dma_request_channel(dma_mask, ntb_dma_filter_fn, + (void *)(unsigned long)node); + if (!qp->dma_chan) + dev_info(&pdev->dev, "Unable to allocate DMA channel\n"); + } else { + qp->dma_chan = NULL; + } + dev_dbg(&pdev->dev, "Using %s memcpy\n", qp->dma_chan ? "DMA" : "CPU"); for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) { entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node); |