diff options
Diffstat (limited to 'drivers/dma/xilinx/zynqmp_dma.c')
| -rw-r--r-- | drivers/dma/xilinx/zynqmp_dma.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c index 9c845c07b107..643aae9679ee 100644 --- a/drivers/dma/xilinx/zynqmp_dma.c +++ b/drivers/dma/xilinx/zynqmp_dma.c @@ -846,6 +846,98 @@ static struct dma_async_tx_descriptor *zynqmp_dma_prep_memcpy( } /** + * zynqmp_dma_prep_slave_sg - prepare descriptors for a memory sg transaction + * @dchan: DMA channel + * @dst_sg: Destination scatter list + * @dst_sg_len: Number of entries in destination scatter list + * @src_sg: Source scatter list + * @src_sg_len: Number of entries in source scatter list + * @flags: transfer ack flags + * + * Return: Async transaction descriptor on success and NULL on failure + */ +static struct dma_async_tx_descriptor *zynqmp_dma_prep_sg( + struct dma_chan *dchan, struct scatterlist *dst_sg, + unsigned int dst_sg_len, struct scatterlist *src_sg, + unsigned int src_sg_len, unsigned long flags) +{ + struct zynqmp_dma_desc_sw *new, *first = NULL; + struct zynqmp_dma_chan *chan = to_chan(dchan); + void *desc = NULL, *prev = NULL; + size_t len, dst_avail, src_avail; + dma_addr_t dma_dst, dma_src; + u32 desc_cnt = 0, i; + struct scatterlist *sg; + + for_each_sg(src_sg, sg, src_sg_len, i) + desc_cnt += DIV_ROUND_UP(sg_dma_len(sg), + ZYNQMP_DMA_MAX_TRANS_LEN); + + spin_lock_bh(&chan->lock); + if (desc_cnt > chan->desc_free_cnt) { + spin_unlock_bh(&chan->lock); + dev_dbg(chan->dev, "chan %p descs are not available\n", chan); + return NULL; + } + chan->desc_free_cnt = chan->desc_free_cnt - desc_cnt; + spin_unlock_bh(&chan->lock); + + dst_avail = sg_dma_len(dst_sg); + src_avail = sg_dma_len(src_sg); + + /* Run until we are out of scatterlist entries */ + while (true) { + /* Allocate and populate the descriptor */ + new = zynqmp_dma_get_descriptor(chan); + desc = (struct zynqmp_dma_desc_ll *)new->src_v; + len = min_t(size_t, src_avail, dst_avail); + len = min_t(size_t, len, ZYNQMP_DMA_MAX_TRANS_LEN); + if (len == 0) + goto fetch; + dma_dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - + dst_avail; + dma_src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - + src_avail; + + zynqmp_dma_config_sg_ll_desc(chan, desc, dma_src, dma_dst, + len, prev); + prev = desc; + dst_avail -= len; + src_avail -= len; + + if (!first) + first = new; + else + list_add_tail(&new->node, &first->tx_list); +fetch: + /* Fetch the next dst scatterlist entry */ + if (dst_avail == 0) { + if (dst_sg_len == 0) + break; + dst_sg = sg_next(dst_sg); + if (dst_sg == NULL) + break; + dst_sg_len--; + dst_avail = sg_dma_len(dst_sg); + } + /* Fetch the next src scatterlist entry */ + if (src_avail == 0) { + if (src_sg_len == 0) + break; + src_sg = sg_next(src_sg); + if (src_sg == NULL) + break; + src_sg_len--; + src_avail = sg_dma_len(src_sg); + } + } + + zynqmp_dma_desc_config_eod(chan, desc); + first->async_tx.flags = flags; + return &first->async_tx; +} + +/** * zynqmp_dma_chan_remove - Channel remove function * @chan: ZynqMP DMA channel pointer */ @@ -1044,9 +1136,11 @@ static int zynqmp_dma_probe(struct platform_device *pdev) INIT_LIST_HEAD(&zdev->common.channels); dma_set_mask(&pdev->dev, DMA_BIT_MASK(44)); + dma_cap_set(DMA_SG, zdev->common.cap_mask); dma_cap_set(DMA_MEMCPY, zdev->common.cap_mask); p = &zdev->common; + p->device_prep_dma_sg = zynqmp_dma_prep_sg; p->device_prep_dma_memcpy = zynqmp_dma_prep_memcpy; p->device_terminate_all = zynqmp_dma_device_terminate_all; p->device_issue_pending = zynqmp_dma_issue_pending; |