net/mlx5e: Store DMA address inside struct page

Use page_pool_set_dma_addr() to store the DMA address of a page inside
struct page, in order to avoid passing struct mlx5e_dma_info to XDP
handlers. Previously, struct mlx5e_dma_info was used to pass both the
DMA address and the page, and it worked well for the single-fragment
case.

When XDP multi buffer is in use, and a fragmented xdp_frame has to be
transmitted, the driver needs to know the DMA addresses of fragments,
however, the array of fragments in struct skb_shared_info doesn't
contain them. In order to pass the DMA addresses, the driver puts them
into struct page itself, which is accessible from the array of fragments
in struct skb_shared_info. The existing XDP handlers are modified to
remove the dependency on struct mlx5e_dma_info.

Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/en.h

@@ -515,7 +515,7 @@ struct mlx5e_xdp_info {
 		} frame;
 		struct {
 			struct mlx5e_rq *rq;
-			struct mlx5e_dma_info di;
+			struct page *page;
 		} page;
 	};
 };

drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h

@@ -44,10 +44,8 @@ int mlx5e_napi_poll(struct napi_struct *napi, int budget);
 int mlx5e_poll_ico_cq(struct mlx5e_cq *cq);
 
 /* RX */
-void mlx5e_page_dma_unmap(struct mlx5e_rq *rq, struct mlx5e_dma_info *dma_info);
-void mlx5e_page_release_dynamic(struct mlx5e_rq *rq,
-				struct mlx5e_dma_info *dma_info,
-				bool recycle);
+void mlx5e_page_dma_unmap(struct mlx5e_rq *rq, struct page *page);
+void mlx5e_page_release_dynamic(struct mlx5e_rq *rq, struct page *page, bool recycle);
 INDIRECT_CALLABLE_DECLARE(bool mlx5e_post_rx_wqes(struct mlx5e_rq *rq));
 INDIRECT_CALLABLE_DECLARE(bool mlx5e_post_rx_mpwqes(struct mlx5e_rq *rq));
 int mlx5e_poll_rx_cq(struct mlx5e_cq *cq, int budget);

drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c

@@ -57,7 +57,7 @@ int mlx5e_xdp_max_mtu(struct mlx5e_params *params, struct mlx5e_xsk_param *xsk)
 
 static inline bool
 mlx5e_xmit_xdp_buff(struct mlx5e_xdpsq *sq, struct mlx5e_rq *rq,
-		    struct mlx5e_dma_info *di, struct xdp_buff *xdp)
+		    struct page *page, struct xdp_buff *xdp)
 {
 	struct mlx5e_xmit_data xdptxd;
 	struct mlx5e_xdp_info xdpi;
@@ -110,21 +110,21 @@ mlx5e_xmit_xdp_buff(struct mlx5e_xdpsq *sq, struct mlx5e_rq *rq,
 
 		xdpi.mode = MLX5E_XDP_XMIT_MODE_PAGE;
 
-		dma_addr = di->addr + (xdpf->data - (void *)xdpf);
+		dma_addr = page_pool_get_dma_addr(page) + (xdpf->data - (void *)xdpf);
 		dma_sync_single_for_device(sq->pdev, dma_addr, xdptxd.len,
 					   DMA_TO_DEVICE);
 
 		xdptxd.dma_addr = dma_addr;
 		xdpi.page.rq    = rq;
-		xdpi.page.di    = *di;
+		xdpi.page.page = page;
 	}
 
 	return INDIRECT_CALL_2(sq->xmit_xdp_frame, mlx5e_xmit_xdp_frame_mpwqe,
 			       mlx5e_xmit_xdp_frame, sq, &xdptxd, &xdpi, 0);
 }
 
 /* returns true if packet was consumed by xdp */
-bool mlx5e_xdp_handle(struct mlx5e_rq *rq, struct mlx5e_dma_info *di,
+bool mlx5e_xdp_handle(struct mlx5e_rq *rq, struct page *page,
 		      struct bpf_prog *prog, struct xdp_buff *xdp)
 {
 	u32 act;
@@ -135,7 +135,7 @@ bool mlx5e_xdp_handle(struct mlx5e_rq *rq, struct mlx5e_dma_info *di,
 	case XDP_PASS:
 		return false;
 	case XDP_TX:
-		if (unlikely(!mlx5e_xmit_xdp_buff(rq->xdpsq, rq, di, xdp)))
+		if (unlikely(!mlx5e_xmit_xdp_buff(rq->xdpsq, rq, page, xdp)))
 			goto xdp_abort;
 		__set_bit(MLX5E_RQ_FLAG_XDP_XMIT, rq->flags); /* non-atomic */
 		return true;
@@ -147,7 +147,7 @@ bool mlx5e_xdp_handle(struct mlx5e_rq *rq, struct mlx5e_dma_info *di,
 		__set_bit(MLX5E_RQ_FLAG_XDP_XMIT, rq->flags);
 		__set_bit(MLX5E_RQ_FLAG_XDP_REDIRECT, rq->flags);
 		if (xdp->rxq->mem.type != MEM_TYPE_XSK_BUFF_POOL)
-			mlx5e_page_dma_unmap(rq, di);
+			mlx5e_page_dma_unmap(rq, page);
 		rq->stats->xdp_redirect++;
 		return true;
 	default:
@@ -384,7 +384,7 @@ static void mlx5e_free_xdpsq_desc(struct mlx5e_xdpsq *sq,
 			break;
 		case MLX5E_XDP_XMIT_MODE_PAGE:
 			/* XDP_TX from the regular RQ */
-			mlx5e_page_release_dynamic(xdpi.page.rq, &xdpi.page.di, recycle);
+			mlx5e_page_release_dynamic(xdpi.page.rq, xdpi.page.page, recycle);
 			break;
 		case MLX5E_XDP_XMIT_MODE_XSK:
 			/* AF_XDP send */

drivers/net/ethernet/mellanox/mlx5/core/en/xdp.h

@@ -47,7 +47,7 @@
 
 struct mlx5e_xsk_param;
 int mlx5e_xdp_max_mtu(struct mlx5e_params *params, struct mlx5e_xsk_param *xsk);
-bool mlx5e_xdp_handle(struct mlx5e_rq *rq, struct mlx5e_dma_info *di,
+bool mlx5e_xdp_handle(struct mlx5e_rq *rq, struct page *page,
 		      struct bpf_prog *prog, struct xdp_buff *xdp);
 void mlx5e_xdp_mpwqe_complete(struct mlx5e_xdpsq *sq);
 bool mlx5e_poll_xdpsq_cq(struct mlx5e_cq *cq);

drivers/net/ethernet/mellanox/mlx5/core/en_main.c

@@ -780,7 +780,7 @@ static void mlx5e_free_rq(struct mlx5e_rq *rq)
 		 * entered, and it's safe to call mlx5e_page_release_dynamic
 		 * directly.
 		 */
-		mlx5e_page_release_dynamic(rq, dma_info, false);
+		mlx5e_page_release_dynamic(rq, dma_info->page, false);
 	}
 
 	xdp_rxq_info_unreg(&rq->xdp_rxq);

drivers/net/ethernet/mellanox/mlx5/core/en_rx.c

@@ -222,8 +222,7 @@ static inline u32 mlx5e_decompress_cqes_start(struct mlx5e_rq *rq,
 	return mlx5e_decompress_cqes_cont(rq, wq, 1, budget_rem) - 1;
 }
 
-static inline bool mlx5e_rx_cache_put(struct mlx5e_rq *rq,
-				      struct mlx5e_dma_info *dma_info)
+static inline bool mlx5e_rx_cache_put(struct mlx5e_rq *rq, struct page *page)
 {
 	struct mlx5e_page_cache *cache = &rq->page_cache;
 	u32 tail_next = (cache->tail + 1) & (MLX5E_CACHE_SIZE - 1);
@@ -234,12 +233,13 @@ static inline bool mlx5e_rx_cache_put(struct mlx5e_rq *rq,
 		return false;
 	}
 
-	if (!dev_page_is_reusable(dma_info->page)) {
+	if (!dev_page_is_reusable(page)) {
 		stats->cache_waive++;
 		return false;
 	}
 
-	cache->page_cache[cache->tail] = *dma_info;
+	cache->page_cache[cache->tail].page = page;
+	cache->page_cache[cache->tail].addr = page_pool_get_dma_addr(page);
 	cache->tail = tail_next;
 	return true;
 }
@@ -287,6 +287,7 @@ static inline int mlx5e_page_alloc_pool(struct mlx5e_rq *rq,
 		dma_info->page = NULL;
 		return -ENOMEM;
 	}
+	page_pool_set_dma_addr(dma_info->page, dma_info->addr);
 
 	return 0;
 }
@@ -300,26 +301,27 @@ static inline int mlx5e_page_alloc(struct mlx5e_rq *rq,
 		return mlx5e_page_alloc_pool(rq, dma_info);
 }
 
-void mlx5e_page_dma_unmap(struct mlx5e_rq *rq, struct mlx5e_dma_info *dma_info)
+void mlx5e_page_dma_unmap(struct mlx5e_rq *rq, struct page *page)
 {
-	dma_unmap_page_attrs(rq->pdev, dma_info->addr, PAGE_SIZE, rq->buff.map_dir,
+	dma_addr_t dma_addr = page_pool_get_dma_addr(page);
+
+	dma_unmap_page_attrs(rq->pdev, dma_addr, PAGE_SIZE, rq->buff.map_dir,
 			     DMA_ATTR_SKIP_CPU_SYNC);
+	page_pool_set_dma_addr(page, 0);
 }
 
-void mlx5e_page_release_dynamic(struct mlx5e_rq *rq,
-				struct mlx5e_dma_info *dma_info,
-				bool recycle)
+void mlx5e_page_release_dynamic(struct mlx5e_rq *rq, struct page *page, bool recycle)
 {
 	if (likely(recycle)) {
-		if (mlx5e_rx_cache_put(rq, dma_info))
+		if (mlx5e_rx_cache_put(rq, page))
 			return;
 
-		mlx5e_page_dma_unmap(rq, dma_info);
-		page_pool_recycle_direct(rq->page_pool, dma_info->page);
+		mlx5e_page_dma_unmap(rq, page);
+		page_pool_recycle_direct(rq->page_pool, page);
 	} else {
-		mlx5e_page_dma_unmap(rq, dma_info);
-		page_pool_release_page(rq->page_pool, dma_info->page);
-		put_page(dma_info->page);
+		mlx5e_page_dma_unmap(rq, page);
+		page_pool_release_page(rq->page_pool, page);
+		put_page(page);
 	}
 }
 
@@ -334,7 +336,7 @@ static inline void mlx5e_page_release(struct mlx5e_rq *rq,
 		 */
 		xsk_buff_free(dma_info->xsk);
 	else
-		mlx5e_page_release_dynamic(rq, dma_info, recycle);
+		mlx5e_page_release_dynamic(rq, dma_info->page, recycle);
 }
 
 static inline int mlx5e_get_rx_frag(struct mlx5e_rq *rq,
@@ -1544,7 +1546,7 @@ mlx5e_skb_from_cqe_linear(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe,
 
 		net_prefetchw(va); /* xdp_frame data area */
 		mlx5e_fill_xdp_buff(rq, va, rx_headroom, cqe_bcnt, &xdp);
-		if (mlx5e_xdp_handle(rq, di, prog, &xdp))
+		if (mlx5e_xdp_handle(rq, di->page, prog, &xdp))
 			return NULL; /* page/packet was consumed by XDP */
 
 		rx_headroom = xdp.data - xdp.data_hard_start;
@@ -1632,7 +1634,7 @@ mlx5e_skb_from_cqe_nonlinear(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe,
 	di = head_wi->di;
 
 	prog = rcu_dereference(rq->xdp_prog);
-	if (prog && mlx5e_xdp_handle(rq, di, prog, &xdp)) {
+	if (prog && mlx5e_xdp_handle(rq, di->page, prog, &xdp)) {
 		if (test_bit(MLX5E_RQ_FLAG_XDP_XMIT, rq->flags)) {
 			int i;
 
@@ -1934,7 +1936,7 @@ mlx5e_skb_from_cqe_mpwrq_linear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *wi,
 
 		net_prefetchw(va); /* xdp_frame data area */
 		mlx5e_fill_xdp_buff(rq, va, rx_headroom, cqe_bcnt, &xdp);
-		if (mlx5e_xdp_handle(rq, di, prog, &xdp)) {
+		if (mlx5e_xdp_handle(rq, di->page, prog, &xdp)) {
 			if (__test_and_clear_bit(MLX5E_RQ_FLAG_XDP_XMIT, rq->flags))
 				__set_bit(page_idx, wi->xdp_xmit_bitmap); /* non-atomic */
 			return NULL; /* page/packet was consumed by XDP */