Kernel/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-01-18 02:46:06 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

dmaengine: pl330: Add IOMMU support to slave tranfers

Browse Source 
Wire up dma_map_resource() for slave transfers, so that we can let the
PL330 use IOMMU-backed DMA mapping ops on systems with an appropriate
IOMMU and RAM above 4GB, to avoid CPU bounce buffering.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Robin Murphy 2017-05-19 15:06:44 +01:00 committed by Vinod Koul
parent 2ea659a9ef
commit 4d6d74e220
1 changed files with 66 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

75
drivers/dma/pl330.c
View File

@ -443,7 +443,10 @@ struct dma_pl330_chan {
/* For D-to-M and M-to-D channels */
int burst_sz; /* the peripheral fifo width */
int burst_len; /* the number of burst */
dma_addr_t fifo_addr;
phys_addr_t fifo_addr;
/* DMA-mapped view of the FIFO; may differ if an IOMMU is present */
dma_addr_t fifo_dma;
enum dma_data_direction dir;
/* for cyclic capability */
bool cyclic;
@ -2120,11 +2123,60 @@ static int pl330_alloc_chan_resources(struct dma_chan *chan)
return 1;
}
/*
* We need the data direction between the DMAC (the dma-mapping "device") and
* the FIFO (the dmaengine "dev"), from the FIFO's point of view. Confusing!
*/
static enum dma_data_direction
pl330_dma_slave_map_dir(enum dma_transfer_direction dir)
{
switch (dir) {
case DMA_MEM_TO_DEV:
return DMA_FROM_DEVICE;
case DMA_DEV_TO_MEM:
return DMA_TO_DEVICE;
case DMA_DEV_TO_DEV:
return DMA_BIDIRECTIONAL;
default:
return DMA_NONE;
}
}
static void pl330_unprep_slave_fifo(struct dma_pl330_chan *pch)
{
if (pch->dir != DMA_NONE)
dma_unmap_resource(pch->chan.device->dev, pch->fifo_dma,
1 << pch->burst_sz, pch->dir, 0);
pch->dir = DMA_NONE;
}
static bool pl330_prep_slave_fifo(struct dma_pl330_chan *pch,
enum dma_transfer_direction dir)
{
struct device *dev = pch->chan.device->dev;
enum dma_data_direction dma_dir = pl330_dma_slave_map_dir(dir);
/* Already mapped for this config? */
if (pch->dir == dma_dir)
return true;
pl330_unprep_slave_fifo(pch);
pch->fifo_dma = dma_map_resource(dev, pch->fifo_addr,
1 << pch->burst_sz, dma_dir, 0);
if (dma_mapping_error(dev, pch->fifo_dma))
return false;
pch->dir = dma_dir;
return true;
}
static int pl330_config(struct dma_chan *chan,
struct dma_slave_config *slave_config)
{
struct dma_pl330_chan *pch = to_pchan(chan);
pl330_unprep_slave_fifo(pch);
if (slave_config->direction == DMA_MEM_TO_DEV) {
if (slave_config->dst_addr)
pch->fifo_addr = slave_config->dst_addr;
@ -2235,6 +2287,7 @@ static void pl330_free_chan_resources(struct dma_chan *chan)
spin_unlock_irqrestore(&pl330->lock, flags);
pm_runtime_mark_last_busy(pch->dmac->ddma.dev);
pm_runtime_put_autosuspend(pch->dmac->ddma.dev);
pl330_unprep_slave_fifo(pch);
}
static int pl330_get_current_xferred_count(struct dma_pl330_chan *pch,
@ -2564,6 +2617,9 @@ static struct dma_async_tx_descriptor *pl330_prep_dma_cyclic(
return NULL;
}
if (!pl330_prep_slave_fifo(pch, direction))
return NULL;
for (i = 0; i < len / period_len; i++) {
desc = pl330_get_desc(pch);
if (!desc) {
@ -2593,12 +2649,12 @@ static struct dma_async_tx_descriptor *pl330_prep_dma_cyclic(
desc->rqcfg.src_inc = 1;
desc->rqcfg.dst_inc = 0;
src = dma_addr;
dst = pch->fifo_addr;
dst = pch->fifo_dma;
break;
case DMA_DEV_TO_MEM:
desc->rqcfg.src_inc = 0;
desc->rqcfg.dst_inc = 1;
src = pch->fifo_addr;
src = pch->fifo_dma;
dst = dma_addr;
break;
default:
@ -2711,12 +2767,12 @@ pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
struct dma_pl330_chan *pch = to_pchan(chan);
struct scatterlist *sg;
int i;
dma_addr_t addr;
if (unlikely(!pch || !sgl || !sg_len))
return NULL;
addr = pch->fifo_addr;
if (!pl330_prep_slave_fifo(pch, direction))
return NULL;
first = NULL;
@ -2742,13 +2798,13 @@ pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
if (direction == DMA_MEM_TO_DEV) {
desc->rqcfg.src_inc = 1;
desc->rqcfg.dst_inc = 0;
fill_px(&desc->px,
addr, sg_dma_address(sg), sg_dma_len(sg));
fill_px(&desc->px, pch->fifo_dma, sg_dma_address(sg),
sg_dma_len(sg));
} else {
desc->rqcfg.src_inc = 0;
desc->rqcfg.dst_inc = 1;
fill_px(&desc->px,
sg_dma_address(sg), addr, sg_dma_len(sg));
fill_px(&desc->px, sg_dma_address(sg), pch->fifo_dma,
sg_dma_len(sg));
}
desc->rqcfg.brst_size = pch->burst_sz;
@ -2906,6 +2962,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
pch->thread = NULL;
pch->chan.device = pd;
pch->dmac = pl330;
pch->dir = DMA_NONE;
/* Add the channel to the DMAC list */
list_add_tail(&pch->chan.device_node, &pd->channels);