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fsldma: implement support for scatterlist to scatterlist copy
Now that the DMAEngine API has support for scatterlist to scatterlist copy, implement support for the Freescale DMA controller. Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Ira Snyder
Dan Williams
parent
a86ee03ce6
commit
c14330417e
@ -38,6 +38,8 @@
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#include <asm/fsldma.h>
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#include "fsldma.h"
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static const char msg_ld_oom[] = "No free memory for link descriptor\n";
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static void dma_init(struct fsldma_chan *chan)
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{
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/* Reset the channel */
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@ -499,7 +501,7 @@ fsl_dma_prep_interrupt(struct dma_chan *dchan, unsigned long flags)
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new = fsl_dma_alloc_descriptor(chan);
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if (!new) {
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dev_err(chan->dev, "No free memory for link descriptor\n");
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dev_err(chan->dev, msg_ld_oom);
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return NULL;
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}
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@ -536,8 +538,7 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy(
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/* Allocate the link descriptor from DMA pool */
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new = fsl_dma_alloc_descriptor(chan);
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if (!new) {
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dev_err(chan->dev,
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"No free memory for link descriptor\n");
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dev_err(chan->dev, msg_ld_oom);
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goto fail;
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}
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#ifdef FSL_DMA_LD_DEBUG
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@ -583,6 +584,125 @@ fail:
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return NULL;
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}
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static struct dma_async_tx_descriptor *fsl_dma_prep_sg(struct dma_chan *dchan,
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struct scatterlist *dst_sg, unsigned int dst_nents,
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struct scatterlist *src_sg, unsigned int src_nents,
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unsigned long flags)
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{
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struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL;
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struct fsldma_chan *chan = to_fsl_chan(dchan);
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size_t dst_avail, src_avail;
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dma_addr_t dst, src;
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size_t len;
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/* basic sanity checks */
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if (dst_nents == 0 || src_nents == 0)
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return NULL;
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if (dst_sg == NULL || src_sg == NULL)
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return NULL;
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/*
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* TODO: should we check that both scatterlists have the same
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* TODO: number of bytes in total? Is that really an error?
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*/
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/* get prepared for the loop */
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dst_avail = sg_dma_len(dst_sg);
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src_avail = sg_dma_len(src_sg);
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/* run until we are out of scatterlist entries */
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while (true) {
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/* create the largest transaction possible */
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len = min_t(size_t, src_avail, dst_avail);
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len = min_t(size_t, len, FSL_DMA_BCR_MAX_CNT);
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if (len == 0)
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goto fetch;
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dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
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src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
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/* allocate and populate the descriptor */
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new = fsl_dma_alloc_descriptor(chan);
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if (!new) {
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dev_err(chan->dev, msg_ld_oom);
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goto fail;
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}
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#ifdef FSL_DMA_LD_DEBUG
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dev_dbg(chan->dev, "new link desc alloc %p\n", new);
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#endif
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set_desc_cnt(chan, &new->hw, len);
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set_desc_src(chan, &new->hw, src);
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set_desc_dst(chan, &new->hw, dst);
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if (!first)
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first = new;
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else
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set_desc_next(chan, &prev->hw, new->async_tx.phys);
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new->async_tx.cookie = 0;
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async_tx_ack(&new->async_tx);
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prev = new;
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/* Insert the link descriptor to the LD ring */
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list_add_tail(&new->node, &first->tx_list);
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/* update metadata */
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dst_avail -= len;
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src_avail -= len;
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fetch:
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/* fetch the next dst scatterlist entry */
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if (dst_avail == 0) {
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/* no more entries: we're done */
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if (dst_nents == 0)
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break;
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/* fetch the next entry: if there are no more: done */
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dst_sg = sg_next(dst_sg);
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if (dst_sg == NULL)
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break;
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dst_nents--;
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dst_avail = sg_dma_len(dst_sg);
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}
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/* fetch the next src scatterlist entry */
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if (src_avail == 0) {
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/* no more entries: we're done */
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if (src_nents == 0)
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break;
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/* fetch the next entry: if there are no more: done */
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src_sg = sg_next(src_sg);
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if (src_sg == NULL)
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break;
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src_nents--;
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src_avail = sg_dma_len(src_sg);
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}
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}
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new->async_tx.flags = flags; /* client is in control of this ack */
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new->async_tx.cookie = -EBUSY;
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/* Set End-of-link to the last link descriptor of new list */
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set_ld_eol(chan, new);
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return &first->async_tx;
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fail:
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if (!first)
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return NULL;
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fsldma_free_desc_list_reverse(chan, &first->tx_list);
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return NULL;
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}
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/**
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* fsl_dma_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
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* @chan: DMA channel
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@ -1327,11 +1447,13 @@ static int __devinit fsldma_of_probe(struct platform_device *op,
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dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
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dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask);
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dma_cap_set(DMA_SG, fdev->common.cap_mask);
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dma_cap_set(DMA_SLAVE, fdev->common.cap_mask);
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fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources;
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fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
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fdev->common.device_prep_dma_interrupt = fsl_dma_prep_interrupt;
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fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy;
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fdev->common.device_prep_dma_sg = fsl_dma_prep_sg;
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fdev->common.device_tx_status = fsl_tx_status;
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fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
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fdev->common.device_prep_slave_sg = fsl_dma_prep_slave_sg;
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