[PATCH 1/1] dmaengine: mxs-dma: switch from dma_coherent to dma_pool

Frank Li
2024-02-19T15:58:01Z

From: Han Xu <han.xu@nxp.com>

Using dma_pool to manage dma descriptor memory.

Signed-off-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
drivers/dma/mxs-dma.c | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
index cfb9962417ef6..a60bf7a22492d 100644
--- a/drivers/dma/mxs-dma.c
+++ b/drivers/dma/mxs-dma.c
@@ -24,6 +24,7 @@
#include <linux/of_dma.h>
#include <linux/list.h>
#include <linux/dma/mxs-dma.h>
+#include <linux/dmapool.h>

#include <asm/irq.h>

@@ -104,6 +105,7 @@ struct mxs_dma_ccw {

#define CCW_BLOCK_SIZE (4 * PAGE_SIZE)
#define NUM_CCW (int)(CCW_BLOCK_SIZE / sizeof(struct mxs_dma_ccw))
+#define CCW_BLOCK_ALGIN 32

struct mxs_dma_chan {
struct mxs_dma_engine *mxs_dma;
@@ -117,6 +119,7 @@ struct mxs_dma_chan {
enum dma_status status;
unsigned int flags;
bool reset;
+ struct dma_pool *ccw_pool;
#define MXS_DMA_SG_LOOP (1 << 0)
#define MXS_DMA_USE_SEMAPHORE (1 << 1)
};
@@ -398,9 +401,8 @@ static int mxs_dma_alloc_chan_resources(struct dma_chan *chan)
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
int ret;

- mxs_chan->ccw = dma_alloc_coherent(mxs_dma->dma_device.dev,
- CCW_BLOCK_SIZE,
- &mxs_chan->ccw_phys, GFP_KERNEL);
+ mxs_chan->ccw = dma_pool_zalloc(mxs_chan->ccw_pool, GFP_ATOMIC, &mxs_chan->ccw_phys);
+
if (!mxs_chan->ccw) {
ret = -ENOMEM;
goto err_alloc;
@@ -428,8 +430,7 @@ static int mxs_dma_alloc_chan_resources(struct dma_chan *chan)
err_clk:
free_irq(mxs_chan->chan_irq, mxs_dma);
err_irq:
- dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE,
- mxs_chan->ccw, mxs_chan->ccw_phys);
+ dma_pool_free(mxs_chan->ccw_pool, mxs_chan->ccw, mxs_chan->ccw_phys);
err_alloc:
return ret;
}
@@ -443,8 +444,7 @@ static void mxs_dma_free_chan_resources(struct dma_chan *chan)

free_irq(mxs_chan->chan_irq, mxs_dma);

- dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE,
- mxs_chan->ccw, mxs_chan->ccw_phys);
+ dma_pool_free(mxs_chan->ccw_pool, mxs_chan->ccw, mxs_chan->ccw_phys);

clk_disable_unprepare(mxs_dma->clk);
}
@@ -745,6 +745,7 @@ static int mxs_dma_probe(struct platform_device *pdev)
struct device_node *np = pdev->dev.of_node;
const struct mxs_dma_type *dma_type;
struct mxs_dma_engine *mxs_dma;
+ struct dma_pool *ccw_pool;
int ret, i;

mxs_dma = devm_kzalloc(&pdev->dev, sizeof(*mxs_dma), GFP_KERNEL);
@@ -797,6 +798,15 @@ static int mxs_dma_probe(struct platform_device *pdev)
mxs_dma->pdev = pdev;
mxs_dma->dma_device.dev = &pdev->dev;

+ ccw_pool = dma_pool_create("ccw_pool", mxs_dma->dma_device.dev, CCW_BLOCK_SIZE,
+ CCW_BLOCK_ALGIN, 0);
+
+ for (i = 0; i < MXS_DMA_CHANNELS; i++) {
+ struct mxs_dma_chan *mxs_chan = &mxs_dma->mxs_chans[i];
+
+ mxs_chan->ccw_pool = ccw_pool;
+ }
+
/* mxs_dma gets 65535 bytes maximum sg size */
dma_set_max_seg_size(mxs_dma->dma_device.dev, MAX_XFER_BYTES);

--
2.34.1