RDMA/hns: Optimize hns buffer allocation flow

When the value of nbufs is 1, the buffer is in direct mode, which may cause
confusion. So optimizes current codes to make it easier to maintain and
understand.

Link: https://lore.kernel.org/r/1586779091-51410-3-git-send-email-liweihang@huawei.com
Signed-off-by: Xi Wang <wangxi11@huawei.com>
Signed-off-by: Lang Cheng <chenglang@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 47 insertions, 56 deletions

diff --git a/drivers/infiniband/hw/hns/hns_roce_alloc.c b/drivers/infiniband/hw/hns/hns_roce_alloc.c
index da574c26e063..e04e7596d979 100644
--- a/drivers/infiniband/hw/hns/hns_roce_alloc.c
+++ b/drivers/infiniband/hw/hns/hns_roce_alloc.c
@@ -157,84 +157,78 @@ void hns_roce_bitmap_cleanup(struct hns_roce_bitmap *bitmap)
 	kfree(bitmap->table);
 }
 
-void hns_roce_buf_free(struct hns_roce_dev *hr_dev, u32 size,
-		       struct hns_roce_buf *buf)
+void hns_roce_buf_free(struct hns_roce_dev *hr_dev, struct hns_roce_buf *buf)
 {
-	int i;
 	struct device *dev = hr_dev->dev;
+	u32 size = buf->size;
+	int i;
+
+	if (size == 0)
+		return;
+
+	buf->size = 0;
 
-	if (buf->nbufs == 1) {
+	if (hns_roce_buf_is_direct(buf)) {
 		dma_free_coherent(dev, size, buf->direct.buf, buf->direct.map);
 	} else {
-		for (i = 0; i < buf->nbufs; ++i)
+		for (i = 0; i < buf->npages; ++i)
 			if (buf->page_list[i].buf)
 				dma_free_coherent(dev, 1 << buf->page_shift,
 						  buf->page_list[i].buf,
 						  buf->page_list[i].map);
 		kfree(buf->page_list);
+		buf->page_list = NULL;
 	}
 }
 
 int hns_roce_buf_alloc(struct hns_roce_dev *hr_dev, u32 size, u32 max_direct,
 		       struct hns_roce_buf *buf, u32 page_shift)
 {
-	int i = 0;
-	dma_addr_t t;
+	struct hns_roce_buf_list *buf_list;
 	struct device *dev = hr_dev->dev;
-	u32 page_size = 1 << page_shift;
-	u32 order;
+	u32 page_size;
+	int i;
+
+	/* The minimum shift of the page accessed by hw is PAGE_ADDR_SHIFT */
+	buf->page_shift = max_t(int, PAGE_ADDR_SHIFT, page_shift);
 
-	/* SQ/RQ buf lease than one page, SQ + RQ = 8K */
+	page_size = 1 << buf->page_shift;
+	buf->npages = DIV_ROUND_UP(size, page_size);
+
+	/* required size is not bigger than one trunk size */
 	if (size <= max_direct) {
-		buf->nbufs = 1;
-		/* Npages calculated by page_size */
-		order = get_order(size);
-		if (order <= page_shift - PAGE_SHIFT)
-			order = 0;
-		else
-			order -= page_shift - PAGE_SHIFT;
-		buf->npages = 1 << order;
-		buf->page_shift = page_shift;
-		/* MTT PA must be recorded in 4k alignment, t is 4k aligned */
-		buf->direct.buf = dma_alloc_coherent(dev, size, &t,
+		buf->page_list = NULL;
+		buf->direct.buf = dma_alloc_coherent(dev, size,
+						     &buf->direct.map,
 						     GFP_KERNEL);
 		if (!buf->direct.buf)
 			return -ENOMEM;
-
-		buf->direct.map = t;
-
-		while (t & ((1 << buf->page_shift) - 1)) {
-			--buf->page_shift;
-			buf->npages *= 2;
-		}
 	} else {
-		buf->nbufs = (size + page_size - 1) / page_size;
-		buf->npages = buf->nbufs;
-		buf->page_shift = page_shift;
-		buf->page_list = kcalloc(buf->nbufs, sizeof(*buf->page_list),
-					 GFP_KERNEL);
-
-		if (!buf->page_list)
+		buf_list = kcalloc(buf->npages, sizeof(*buf_list), GFP_KERNEL);
+		if (!buf_list)
 			return -ENOMEM;
 
-		for (i = 0; i < buf->nbufs; ++i) {
-			buf->page_list[i].buf = dma_alloc_coherent(dev,
-								   page_size,
-								   &t,
-								   GFP_KERNEL);
-
-			if (!buf->page_list[i].buf)
-				goto err_free;
+		for (i = 0; i < buf->npages; i++) {
+			buf_list[i].buf = dma_alloc_coherent(dev, page_size,
+							     &buf_list[i].map,
+							     GFP_KERNEL);
+			if (!buf_list[i].buf)
+				break;
+		}
 
-			buf->page_list[i].map = t;
+		if (i != buf->npages && i > 0) {
+			while (i-- > 0)
+				dma_free_coherent(dev, page_size,
+						  buf_list[i].buf,
+						  buf_list[i].map);
+			kfree(buf_list);
+			return -ENOMEM;
 		}
+		buf->page_list = buf_list;
 	}
+	buf->size = size;
 
 	return 0;
-
-err_free:
-	hns_roce_buf_free(hr_dev, size, buf);
-	return -ENOMEM;
 }
 
 int hns_roce_get_kmem_bufs(struct hns_roce_dev *hr_dev, dma_addr_t *bufs,
@@ -246,18 +240,14 @@ int hns_roce_get_kmem_bufs(struct hns_roce_dev *hr_dev, dma_addr_t *bufs,
 	end = start + buf_cnt;
 	if (end > buf->npages) {
 		dev_err(hr_dev->dev,
-			"invalid kmem region,offset %d,buf_cnt %d,total %d!\n",
+			"Failed to check kmem bufs, end %d + %d total %d!\n",
 			start, buf_cnt, buf->npages);
 		return -EINVAL;
 	}
 
 	total = 0;
 	for (i = start; i < end; i++)
-		if (buf->nbufs == 1)
-			bufs[total++] = buf->direct.map +
-					((dma_addr_t)i << buf->page_shift);
-		else
-			bufs[total++] = buf->page_list[i].map;
+		bufs[total++] = hns_roce_buf_page(buf, i);
 
 	return total;
 }
@@ -271,8 +261,9 @@ int hns_roce_get_umem_bufs(struct hns_roce_dev *hr_dev, dma_addr_t *bufs,
 	int idx = 0;
 	u64 addr;
 
-	if (page_shift < PAGE_SHIFT) {
-		dev_err(hr_dev->dev, "invalid page shift %d!\n", page_shift);
+	if (page_shift < PAGE_ADDR_SHIFT) {
+		dev_err(hr_dev->dev, "Failed to check umem page shift %d!\n",
+			page_shift);
 		return -EINVAL;
 	}