[PATCH V4 1/2] dmaengine: sprd: Optimize the sprd_dma_prep_dma_memcpy()

From: Baolin Wang
Date: Wed May 23 2018 - 04:40:58 EST


From: Eric Long <eric.long@xxxxxxxxxxxxxx>

This is one preparation patch, we can use default DMA configuration to
implement the device_prep_dma_memcpy() interface instead of issuing
sprd_dma_config().

We will implement one new sprd_dma_config() function with introducing
device_prep_slave_sg() interface in following patch. So we can remove
the obsolete sprd_dma_config() firstly.

Signed-off-by: Eric Long <eric.long@xxxxxxxxxxxxxx>
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
---
Changes since v3:
- No updates.

Changes since v2:
- Change logic to make code more readable.

Changes since v1:
- No updates.
---
drivers/dma/sprd-dma.c | 167 +++++++++++-------------------------------------
1 file changed, 39 insertions(+), 128 deletions(-)

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index e715d07..924ada4 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -552,147 +552,58 @@ static void sprd_dma_issue_pending(struct dma_chan *chan)
spin_unlock_irqrestore(&schan->vc.lock, flags);
}

-static int sprd_dma_config(struct dma_chan *chan, struct sprd_dma_desc *sdesc,
- dma_addr_t dest, dma_addr_t src, size_t len)
-{
- struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
- struct sprd_dma_chn_hw *hw = &sdesc->chn_hw;
- u32 datawidth, src_step, des_step, fragment_len;
- u32 block_len, req_mode, irq_mode, transcation_len;
- u32 fix_mode = 0, fix_en = 0;
-
- if (IS_ALIGNED(len, 4)) {
- datawidth = SPRD_DMA_DATAWIDTH_4_BYTES;
- src_step = SPRD_DMA_WORD_STEP;
- des_step = SPRD_DMA_WORD_STEP;
- } else if (IS_ALIGNED(len, 2)) {
- datawidth = SPRD_DMA_DATAWIDTH_2_BYTES;
- src_step = SPRD_DMA_SHORT_STEP;
- des_step = SPRD_DMA_SHORT_STEP;
- } else {
- datawidth = SPRD_DMA_DATAWIDTH_1_BYTE;
- src_step = SPRD_DMA_BYTE_STEP;
- des_step = SPRD_DMA_BYTE_STEP;
- }
-
- fragment_len = SPRD_DMA_MEMCPY_MIN_SIZE;
- if (len <= SPRD_DMA_BLK_LEN_MASK) {
- block_len = len;
- transcation_len = 0;
- req_mode = SPRD_DMA_BLK_REQ;
- irq_mode = SPRD_DMA_BLK_INT;
- } else {
- block_len = SPRD_DMA_MEMCPY_MIN_SIZE;
- transcation_len = len;
- req_mode = SPRD_DMA_TRANS_REQ;
- irq_mode = SPRD_DMA_TRANS_INT;
- }
-
- hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE_OFFSET;
- hw->wrap_ptr = (u32)((src >> SPRD_DMA_HIGH_ADDR_OFFSET) &
- SPRD_DMA_HIGH_ADDR_MASK);
- hw->wrap_to = (u32)((dest >> SPRD_DMA_HIGH_ADDR_OFFSET) &
- SPRD_DMA_HIGH_ADDR_MASK);
-
- hw->src_addr = (u32)(src & SPRD_DMA_LOW_ADDR_MASK);
- hw->des_addr = (u32)(dest & SPRD_DMA_LOW_ADDR_MASK);
-
- if ((src_step != 0 && des_step != 0) || (src_step | des_step) == 0) {
- fix_en = 0;
- } else {
- fix_en = 1;
- if (src_step)
- fix_mode = 1;
- else
- fix_mode = 0;
- }
-
- hw->frg_len = datawidth << SPRD_DMA_SRC_DATAWIDTH_OFFSET |
- datawidth << SPRD_DMA_DES_DATAWIDTH_OFFSET |
- req_mode << SPRD_DMA_REQ_MODE_OFFSET |
- fix_mode << SPRD_DMA_FIX_SEL_OFFSET |
- fix_en << SPRD_DMA_FIX_EN_OFFSET |
- (fragment_len & SPRD_DMA_FRG_LEN_MASK);
- hw->blk_len = block_len & SPRD_DMA_BLK_LEN_MASK;
-
- hw->intc = SPRD_DMA_CFG_ERR_INT_EN;
-
- switch (irq_mode) {
- case SPRD_DMA_NO_INT:
- break;
-
- case SPRD_DMA_FRAG_INT:
- hw->intc |= SPRD_DMA_FRAG_INT_EN;
- break;
-
- case SPRD_DMA_BLK_INT:
- hw->intc |= SPRD_DMA_BLK_INT_EN;
- break;
-
- case SPRD_DMA_BLK_FRAG_INT:
- hw->intc |= SPRD_DMA_BLK_INT_EN | SPRD_DMA_FRAG_INT_EN;
- break;
-
- case SPRD_DMA_TRANS_INT:
- hw->intc |= SPRD_DMA_TRANS_INT_EN;
- break;
-
- case SPRD_DMA_TRANS_FRAG_INT:
- hw->intc |= SPRD_DMA_TRANS_INT_EN | SPRD_DMA_FRAG_INT_EN;
- break;
-
- case SPRD_DMA_TRANS_BLK_INT:
- hw->intc |= SPRD_DMA_TRANS_INT_EN | SPRD_DMA_BLK_INT_EN;
- break;
-
- case SPRD_DMA_LIST_INT:
- hw->intc |= SPRD_DMA_LIST_INT_EN;
- break;
-
- case SPRD_DMA_CFGERR_INT:
- hw->intc |= SPRD_DMA_CFG_ERR_INT_EN;
- break;
-
- default:
- dev_err(sdev->dma_dev.dev, "invalid irq mode\n");
- return -EINVAL;
- }
-
- if (transcation_len == 0)
- hw->trsc_len = block_len & SPRD_DMA_TRSC_LEN_MASK;
- else
- hw->trsc_len = transcation_len & SPRD_DMA_TRSC_LEN_MASK;
-
- hw->trsf_step = (des_step & SPRD_DMA_TRSF_STEP_MASK) <<
- SPRD_DMA_DEST_TRSF_STEP_OFFSET |
- (src_step & SPRD_DMA_TRSF_STEP_MASK) <<
- SPRD_DMA_SRC_TRSF_STEP_OFFSET;
-
- hw->frg_step = 0;
- hw->src_blk_step = 0;
- hw->des_blk_step = 0;
- hw->src_blk_step = 0;
- return 0;
-}
-
static struct dma_async_tx_descriptor *
sprd_dma_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
size_t len, unsigned long flags)
{
struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
struct sprd_dma_desc *sdesc;
- int ret;
+ struct sprd_dma_chn_hw *hw;
+ enum sprd_dma_datawidth datawidth;
+ u32 step, temp;

sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
if (!sdesc)
return NULL;

- ret = sprd_dma_config(chan, sdesc, dest, src, len);
- if (ret) {
- kfree(sdesc);
- return NULL;
+ hw = &sdesc->chn_hw;
+
+ hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE_OFFSET;
+ hw->intc = SPRD_DMA_TRANS_INT | SPRD_DMA_CFG_ERR_INT_EN;
+ hw->src_addr = src & SPRD_DMA_LOW_ADDR_MASK;
+ hw->des_addr = dest & SPRD_DMA_LOW_ADDR_MASK;
+ hw->wrap_ptr = (src >> SPRD_DMA_HIGH_ADDR_OFFSET) &
+ SPRD_DMA_HIGH_ADDR_MASK;
+ hw->wrap_to = (dest >> SPRD_DMA_HIGH_ADDR_OFFSET) &
+ SPRD_DMA_HIGH_ADDR_MASK;
+
+ if (IS_ALIGNED(len, 8)) {
+ datawidth = SPRD_DMA_DATAWIDTH_8_BYTES;
+ step = SPRD_DMA_DWORD_STEP;
+ } else if (IS_ALIGNED(len, 4)) {
+ datawidth = SPRD_DMA_DATAWIDTH_4_BYTES;
+ step = SPRD_DMA_WORD_STEP;
+ } else if (IS_ALIGNED(len, 2)) {
+ datawidth = SPRD_DMA_DATAWIDTH_2_BYTES;
+ step = SPRD_DMA_SHORT_STEP;
+ } else {
+ datawidth = SPRD_DMA_DATAWIDTH_1_BYTE;
+ step = SPRD_DMA_BYTE_STEP;
}

+ temp = datawidth << SPRD_DMA_SRC_DATAWIDTH_OFFSET;
+ temp |= datawidth << SPRD_DMA_DES_DATAWIDTH_OFFSET;
+ temp |= SPRD_DMA_TRANS_REQ << SPRD_DMA_REQ_MODE_OFFSET;
+ temp |= len & SPRD_DMA_FRG_LEN_MASK;
+ hw->frg_len = temp;
+
+ hw->blk_len = len & SPRD_DMA_BLK_LEN_MASK;
+ hw->trsc_len = len & SPRD_DMA_TRSC_LEN_MASK;
+
+ temp = (step & SPRD_DMA_TRSF_STEP_MASK) << SPRD_DMA_DEST_TRSF_STEP_OFFSET;
+ temp |= (step & SPRD_DMA_TRSF_STEP_MASK) << SPRD_DMA_SRC_TRSF_STEP_OFFSET;
+ hw->trsf_step = temp;
+
return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
}

--
1.7.9.5