Enable client to resubmit already processed descriptors
in order to save descriptor creation time.
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mord...@st.com>
---
Version history:
v1:
* Initial
---
---
drivers/dma/stm32-dma.c | 84 +++++++++++++++++++++++++++++++------------------
1 file changed, 54 insertions(+), 30 deletions(-)
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index 1571f2f..fac44ed 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -836,34 +836,8 @@ static int stm32_dma_mdma_start(struct stm32_dma_chan
*chan,
{
struct stm32_dma_mdma *mchan = &chan->mchan;
struct stm32_dma_mdma_desc *m_desc = &sg_req->m_desc;
- struct dma_slave_config config;
int ret;
- /* Configure MDMA channel */
- memset(&config, 0, sizeof(config));
- if (mchan->dir == DMA_MEM_TO_DEV)
- config.dst_addr = mchan->sram_buf;
- else
- config.src_addr = mchan->sram_buf;
-
- ret = dmaengine_slave_config(mchan->chan, &config);
- if (ret < 0)
- goto error;
-
- /* Prepare MDMA descriptor */
- m_desc->desc = dmaengine_prep_slave_sg(mchan->chan, m_desc->sgt.sgl,
- m_desc->sgt.nents, mchan->dir,
- DMA_PREP_INTERRUPT);
- if (!m_desc->desc) {
- ret = -EINVAL;
- goto error;
- }
-
- if (mchan->dir != DMA_MEM_TO_DEV) {
- m_desc->desc->callback_result = stm32_mdma_chan_complete;
- m_desc->desc->callback_param = chan;
- }
-
ret = dma_submit_error(dmaengine_submit(m_desc->desc));
if (ret < 0) {
dev_err(chan2dev(chan), "MDMA submit failed\n");
@@ -1001,6 +975,7 @@ static void stm32_dma_start_transfer(struct stm32_dma_chan
*chan)
chan->next_sg++;
+ reg->dma_scr &= ~STM32_DMA_SCR_EN;
stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
stm32_dma_write(dmadev, STM32_DMA_SPAR(chan->id), reg->dma_spar);
stm32_dma_write(dmadev, STM32_DMA_SM0AR(chan->id), reg->dma_sm0ar);
@@ -1238,9 +1213,11 @@ static void stm32_dma_clear_reg(struct
stm32_dma_chan_reg *regs)
static int stm32_dma_mdma_prep_slave_sg(struct stm32_dma_chan *chan,
struct scatterlist *sgl, u32 sg_len,
- struct stm32_dma_desc *desc)
+ struct stm32_dma_desc *desc,
+ unsigned long flags)
{
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
+ struct stm32_dma_mdma *mchan = &chan->mchan;
struct scatterlist *sg, *m_sg;
dma_addr_t dma_buf;
u32 len, num_sgs, sram_period;
@@ -1256,12 +1233,13 @@ static int stm32_dma_mdma_prep_slave_sg(struct
stm32_dma_chan *chan,
for_each_sg(sgl, sg, sg_len, i) {
struct stm32_dma_mdma_desc *m_desc = &desc->sg_req[i].m_desc;
+ struct dma_slave_config config;
len = sg_dma_len(sg);
desc->sg_req[i].stm32_sgl_req = *sg;
num_sgs = 1;
- if (chan->mchan.dir == DMA_MEM_TO_DEV) {
+ if (mchan->dir == DMA_MEM_TO_DEV) {
if (len > chan->sram_size) {
dev_err(chan2dev(chan),
"max buf size = %d bytes\n",
@@ -1293,6 +1271,38 @@ static int stm32_dma_mdma_prep_slave_sg(struct
stm32_dma_chan *chan,
dma_buf += bytes;
len -= bytes;
}
+
+ /* Configure MDMA channel */
+ memset(&config, 0, sizeof(config));
+ if (mchan->dir == DMA_MEM_TO_DEV)
+ config.dst_addr = desc->dma_buf;
+ else
+ config.src_addr = desc->dma_buf;
+
+ ret = dmaengine_slave_config(mchan->chan, &config);
+ if (ret < 0)
+ goto err;
+
+ /* Prepare MDMA descriptor */
+ m_desc->desc = dmaengine_prep_slave_sg(mchan->chan,
+ m_desc->sgt.sgl,
+ m_desc->sgt.nents,
+ mchan->dir,
+ DMA_PREP_INTERRUPT);
+
+ if (!m_desc->desc) {
+ ret = -EINVAL;
+ goto err;
+ }
+
+ if (flags & DMA_CTRL_REUSE)
+ dmaengine_desc_set_reuse(m_desc->desc);
+
+ if (mchan->dir != DMA_MEM_TO_DEV) {
+ m_desc->desc->callback_result =
+ stm32_mdma_chan_complete;
+ m_desc->desc->callback_param = chan;
+ }
}
chan->mchan.sram_buf = desc->dma_buf;
@@ -1302,8 +1312,12 @@ static int stm32_dma_mdma_prep_slave_sg(struct
stm32_dma_chan *chan,
return 0;
err:
- for (j = 0; j < i; j++)
+ for (j = 0; j < i; j++) {
+ struct stm32_dma_mdma_desc *m_desc = &desc->sg_req[j].m_desc;
+
+ m_desc->desc = NULL;
sg_free_table(&desc->sg_req[j].m_desc.sgt);
+ }
free_alloc:
gen_pool_free(dmadev->sram_pool, (unsigned long)desc->dma_buf_cpu,
chan->sram_size);
@@ -1385,7 +1399,8 @@ static struct dma_async_tx_descriptor
*stm32_dma_prep_slave_sg(
struct scatterlist *s, *_sgl;
chan->mchan.dir = direction;
- ret = stm32_dma_mdma_prep_slave_sg(chan, sgl, sg_len, desc);
+ ret = stm32_dma_mdma_prep_slave_sg(chan, sgl, sg_len, desc,
+ flags);
if (ret < 0)
return NULL;
@@ -1791,6 +1806,14 @@ static void stm32_dma_desc_free(struct virt_dma_desc
*vdesc)
int i;
if (chan->use_mdma) {
+ struct stm32_dma_mdma_desc *m_desc;
+
+ for (i = 0; i < desc->num_sgs; i++) {
+ m_desc = &desc->sg_req[i].m_desc;
+ dmaengine_desc_free(m_desc->desc);
+ m_desc->desc = NULL;
+ }
+
for (i = 0; i < desc->num_sgs; i++)
sg_free_table(&desc->sg_req[i].m_desc.sgt);
@@ -1934,6 +1957,7 @@ static int stm32_dma_probe(struct platform_device *pdev)
dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
dd->max_burst = STM32_DMA_MAX_BURST;
+ dd->descriptor_reuse = true;
dd->dev = &pdev->dev;
INIT_LIST_HEAD(&dd->channels);
--
2.7.4
