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From:   Cai Huoqing <caihuoqing@baidu.com>
To:     <caihuoqing@baidu.com>
CC:     Lijun Ou <oulijun@huawei.com>, Weihang Li <liweihang@huawei.com>,
        "Doug Ledford" <dledford@redhat.com>,
        Jason Gunthorpe <jgg@ziepe.ca>, <linux-rdma@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: [PATCH] RDMA/hns: Use dma_alloc_coherent() instead of kmalloc/dma_map_single()
Date:   Sun, 26 Sep 2021 14:11:15 +0800
Message-ID: <20210926061116.282-1-caihuoqing@baidu.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Replacing kmalloc/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 <caihuoqing@baidu.com>
---
 drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
index 5b9953105752..380445f98a49 100644
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
@@ -1165,32 +1165,22 @@ static int hns_roce_alloc_cmq_desc(struct hns_roce_dev *hr_dev,
 {
 	int size = ring->desc_num * sizeof(struct hns_roce_cmq_desc);
 
-	ring->desc = kzalloc(size, GFP_KERNEL);
+	ring->desc = dma_alloc_coherent(hr_dev->dev, size,
+					&ring->desc_dma_addr, GFP_KERNEL);
 	if (!ring->desc)
 		return -ENOMEM;
 
-	ring->desc_dma_addr = dma_map_single(hr_dev->dev, ring->desc, size,
-					     DMA_BIDIRECTIONAL);
-	if (dma_mapping_error(hr_dev->dev, ring->desc_dma_addr)) {
-		ring->desc_dma_addr = 0;
-		kfree(ring->desc);
-		ring->desc = NULL;
-
-		return -ENOMEM;
-	}
-
 	return 0;
 }
 
 static void hns_roce_free_cmq_desc(struct hns_roce_dev *hr_dev,
 				   struct hns_roce_v2_cmq_ring *ring)
 {
-	dma_unmap_single(hr_dev->dev, ring->desc_dma_addr,
-			 ring->desc_num * sizeof(struct hns_roce_cmq_desc),
-			 DMA_BIDIRECTIONAL);
+	dma_free_coherent(hr_dev->dev,
+			  ring->desc_num * sizeof(struct hns_roce_cmq_desc),
+			  ring->desc, ring->desc_dma_addr);
 
 	ring->desc_dma_addr = 0;
-	kfree(ring->desc);
 }
 
 static int init_csq(struct hns_roce_dev *hr_dev,
-- 
2.25.1