[PATCH v6 7/9] nvmet: pci-epf: Use dmaengine_prep_config_single_safe() API

From: Frank Li <[email protected]>

Use the new dmaengine_prep_config_single_safe() API to combine the
configuration and descriptor preparation into a single call.

Since dmaengine_prep_config_single_safe() performs the configuration and
preparation atomically and the mutex can be removed.

Tested-by: Niklas Cassel <[email protected]>
Acked-by: Manivannan Sadhasivam <[email protected]>
Signed-off-by: Frank Li <[email protected]>
---
change in v6
- remove local unused variable lock (sashika AI)
---
 drivers/nvme/target/pci-epf.c | 21 ++++-----------------
 1 file changed, 4 insertions(+), 17 deletions(-)

diff --git a/drivers/nvme/target/pci-epf.c b/drivers/nvme/target/pci-epf.c
index 2afe8f4d0e461..f917d6ec278b7 100644
--- a/drivers/nvme/target/pci-epf.c
+++ b/drivers/nvme/target/pci-epf.c
@@ -368,18 +368,15 @@ static int nvmet_pci_epf_dma_transfer(struct nvmet_pci_epf *nvme_epf,
 	struct dma_chan *chan;
 	dma_cookie_t cookie;
 	dma_addr_t dma_addr;
-	struct mutex *lock;
 	int ret;
 
 	switch (dir) {
 	case DMA_FROM_DEVICE:
-		lock = &nvme_epf->dma_rx_lock;
 		chan = nvme_epf->dma_rx_chan;
 		sconf.direction = DMA_DEV_TO_MEM;
 		sconf.src_addr = seg->pci_addr;
 		break;
 	case DMA_TO_DEVICE:
-		lock = &nvme_epf->dma_tx_lock;
 		chan = nvme_epf->dma_tx_chan;
 		sconf.direction = DMA_MEM_TO_DEV;
 		sconf.dst_addr = seg->pci_addr;
@@ -388,22 +385,15 @@ static int nvmet_pci_epf_dma_transfer(struct nvmet_pci_epf *nvme_epf,
 		return -EINVAL;
 	}
 
-	mutex_lock(lock);
-
 	dma_dev = dmaengine_get_dma_device(chan);
 	dma_addr = dma_map_single(dma_dev, seg->buf, seg->length, dir);
 	ret = dma_mapping_error(dma_dev, dma_addr);
 	if (ret)
-		goto unlock;
-
-	ret = dmaengine_slave_config(chan, &sconf);
-	if (ret) {
-		dev_err(dev, "Failed to configure DMA channel\n");
-		goto unmap;
-	}
+		return ret;
 
-	desc = dmaengine_prep_slave_single(chan, dma_addr, seg->length,
-					   sconf.direction, DMA_CTRL_ACK);
+	desc = dmaengine_prep_config_single_safe(chan, dma_addr, seg->length,
+						 sconf.direction,
+						 DMA_CTRL_ACK, &sconf);
 	if (!desc) {
 		dev_err(dev, "Failed to prepare DMA\n");
 		ret = -EIO;
@@ -426,9 +416,6 @@ static int nvmet_pci_epf_dma_transfer(struct nvmet_pci_epf *nvme_epf,
 unmap:
 	dma_unmap_single(dma_dev, dma_addr, seg->length, dir);
 
-unlock:
-	mutex_unlock(lock);
-
 	return ret;
 }
 

-- 
2.43.0