crypto: octeontx2 - Use dma_alloc_coherent() instead of kzalloc/dma_map_single()

Commit Message

Cai,Huoqing Oct. 10, 2021, 4 p.m. UTC

Replacing kzalloc/kfree/dma_map_single/dma_unmap_single()
with dma_alloc_coherent/dma_free_coherent() helps to reduce
code size, and simplify the code, and coherent DMA will not
clear the cache every time.

Signed-off-by: Cai Huoqing <[e-mail]>
---
 drivers/crypto/marvell/octeontx2/otx2_cptpf_ucode.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

Comments

Christoph Hellwig Oct. 11, 2021, 8:38 a.m. UTC | #1

On Mon, Oct 11, 2021 at 12:00:04AM +0800, Cai Huoqing wrote:
> Replacing kzalloc/kfree/dma_map_single/dma_unmap_single()
> with dma_alloc_coherent/dma_free_coherent() helps to reduce
> code size, and simplify the code, and coherent DMA will not
> clear the cache every time.

As just explained in another patch like this please qualify the
savings as we have actual results that shows the reverse of your claims.

Patch

diff --git a/drivers/crypto/marvell/octeontx2/otx2_cptpf_ucode.c b/drivers/crypto/marvell/octeontx2/otx2_cptpf_ucode.c
index dff34b3ec09e..60d62ce049a6 100644
--- a/drivers/crypto/marvell/octeontx2/otx2_cptpf_ucode.c
+++ b/drivers/crypto/marvell/octeontx2/otx2_cptpf_ucode.c
@@ -1449,18 +1449,11 @@  int otx2_cpt_discover_eng_capabilities(struct otx2_cptpf_dev *cptpf)
 	compl_rlen = ALIGN(sizeof(union otx2_cpt_res_s), OTX2_CPT_DMA_MINALIGN);
 	len = compl_rlen + LOADFVC_RLEN;
 
-	result = kzalloc(len, GFP_KERNEL);
+	result = dma_alloc_coherent(&pdev->dev, len, &rptr_baddr, GFP_KERNEL);
 	if (!result) {
 		ret = -ENOMEM;
 		goto lf_cleanup;
 	}
-	rptr_baddr = dma_map_single(&pdev->dev, (void *)result, len,
-				    DMA_BIDIRECTIONAL);
-	if (dma_mapping_error(&pdev->dev, rptr_baddr)) {
-		dev_err(&pdev->dev, "DMA mapping failed\n");
-		ret = -EFAULT;
-		goto free_result;
-	}
 	rptr = (u8 *)result + compl_rlen;
 
 	/* Fill in the command */
@@ -1489,11 +1482,9 @@  int otx2_cpt_discover_eng_capabilities(struct otx2_cptpf_dev *cptpf)
 
 		cptpf->eng_caps[etype].u = be64_to_cpup(rptr);
 	}
-	dma_unmap_single(&pdev->dev, rptr_baddr, len, DMA_BIDIRECTIONAL);
+	dma_free_coherent(&pdev->dev, len, (void *)result, rptr_baddr);
 	cptpf->is_eng_caps_discovered = true;
 
-free_result:
-	kfree(result);
 lf_cleanup:
 	otx2_cptlf_shutdown(&cptpf->lfs);
 delete_grps: