[PATCH net-next v3 7/7] bnxt_en: add support for device memory tcp

[Taehee Yoo <ap420073@gmail.com>]

Currently, bnxt_en driver satisfies the requirements of Device memory
TCP, which is tcp-data-split.
So, it implements Device memory TCP for bnxt_en driver.

From now on, the aggregation ring handles netmem_ref instead of page
regardless of the on/off of netmem.
So, for the aggregation ring, memory will be handled with the netmem
page_pool API instead of generic page_pool API.

If Devmem is enabled, netmem_ref is used as-is and if Devmem is not
enabled, netmem_ref will be converted to page and that is used.

Driver recognizes whether the devmem is set or unset based on the
mp_params.mp_priv is not NULL.
Only if devmem is set, it passes PP_FLAG_ALLOW_UNREADABLE_NETMEM.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v3:
 - Patch added

 drivers/net/ethernet/broadcom/Kconfig     |  1 +
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 98 +++++++++++++++--------
 drivers/net/ethernet/broadcom/bnxt/bnxt.h |  2 +-
 3 files changed, 66 insertions(+), 35 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/Kconfig b/drivers/net/ethernet/broadcom/Kconfig
index 75ca3ddda1f5..f37ff12d4746 100644
--- a/drivers/net/ethernet/broadcom/Kconfig
+++ b/drivers/net/ethernet/broadcom/Kconfig
@@ -211,6 +211,7 @@ config BNXT
 	select FW_LOADER
 	select LIBCRC32C
 	select NET_DEVLINK
+	select NET_DEVMEM
 	select PAGE_POOL
 	select DIMLIB
 	select AUXILIARY_BUS
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 872b15842b11..64e07d247f97 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -55,6 +55,7 @@
 #include <net/page_pool/helpers.h>
 #include <linux/align.h>
 #include <net/netdev_queues.h>
+#include <net/netdev_rx_queue.h>
 
 #include "bnxt_hsi.h"
 #include "bnxt.h"
@@ -863,6 +864,22 @@ static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int budget)
 		bnapi->events &= ~BNXT_TX_CMP_EVENT;
 }
 
+static netmem_ref __bnxt_alloc_rx_netmem(struct bnxt *bp, dma_addr_t *mapping,
+					 struct bnxt_rx_ring_info *rxr,
+					 unsigned int *offset,
+					 gfp_t gfp)
+{
+	netmem_ref netmem;
+
+	netmem = page_pool_alloc_netmem(rxr->page_pool, GFP_ATOMIC);
+	if (!netmem)
+		return 0;
+	*offset = 0;
+
+	*mapping = page_pool_get_dma_addr_netmem(netmem) + *offset;
+	return netmem;
+}
+
 static struct page *__bnxt_alloc_rx_page(struct bnxt *bp, dma_addr_t *mapping,
 					 struct bnxt_rx_ring_info *rxr,
 					 unsigned int *offset,
@@ -972,21 +989,21 @@ static inline u16 bnxt_find_next_agg_idx(struct bnxt_rx_ring_info *rxr, u16 idx)
 	return next;
 }
 
-static inline int bnxt_alloc_rx_page(struct bnxt *bp,
-				     struct bnxt_rx_ring_info *rxr,
-				     u16 prod, gfp_t gfp)
+static inline int bnxt_alloc_rx_netmem(struct bnxt *bp,
+				       struct bnxt_rx_ring_info *rxr,
+				       u16 prod, gfp_t gfp)
 {
 	struct rx_bd *rxbd =
 		&rxr->rx_agg_desc_ring[RX_AGG_RING(bp, prod)][RX_IDX(prod)];
 	struct bnxt_sw_rx_agg_bd *rx_agg_buf;
-	struct page *page;
+	netmem_ref netmem;
 	dma_addr_t mapping;
 	u16 sw_prod = rxr->rx_sw_agg_prod;
 	unsigned int offset = 0;
 
-	page = __bnxt_alloc_rx_page(bp, &mapping, rxr, &offset, gfp);
+	netmem = __bnxt_alloc_rx_netmem(bp, &mapping, rxr, &offset, gfp);
 
-	if (!page)
+	if (!netmem)
 		return -ENOMEM;
 
 	if (unlikely(test_bit(sw_prod, rxr->rx_agg_bmap)))
@@ -996,7 +1013,7 @@ static inline int bnxt_alloc_rx_page(struct bnxt *bp,
 	rx_agg_buf = &rxr->rx_agg_ring[sw_prod];
 	rxr->rx_sw_agg_prod = RING_RX_AGG(bp, NEXT_RX_AGG(sw_prod));
 
-	rx_agg_buf->page = page;
+	rx_agg_buf->netmem = netmem;
 	rx_agg_buf->offset = offset;
 	rx_agg_buf->mapping = mapping;
 	rxbd->rx_bd_haddr = cpu_to_le64(mapping);
@@ -1044,7 +1061,7 @@ static void bnxt_reuse_rx_agg_bufs(struct bnxt_cp_ring_info *cpr, u16 idx,
 		struct rx_agg_cmp *agg;
 		struct bnxt_sw_rx_agg_bd *cons_rx_buf, *prod_rx_buf;
 		struct rx_bd *prod_bd;
-		struct page *page;
+		netmem_ref netmem;
 
 		if (p5_tpa)
 			agg = bnxt_get_tpa_agg_p5(bp, rxr, idx, start + i);
@@ -1061,11 +1078,11 @@ static void bnxt_reuse_rx_agg_bufs(struct bnxt_cp_ring_info *cpr, u16 idx,
 		cons_rx_buf = &rxr->rx_agg_ring[cons];
 
 		/* It is possible for sw_prod to be equal to cons, so
-		 * set cons_rx_buf->page to NULL first.
+		 * set cons_rx_buf->netmem to 0 first.
 		 */
-		page = cons_rx_buf->page;
-		cons_rx_buf->page = NULL;
-		prod_rx_buf->page = page;
+		netmem = cons_rx_buf->netmem;
+		cons_rx_buf->netmem = 0;
+		prod_rx_buf->netmem = netmem;
 		prod_rx_buf->offset = cons_rx_buf->offset;
 
 		prod_rx_buf->mapping = cons_rx_buf->mapping;
@@ -1192,6 +1209,7 @@ static struct sk_buff *bnxt_rx_skb(struct bnxt *bp,
 
 static u32 __bnxt_rx_agg_pages(struct bnxt *bp,
 			       struct bnxt_cp_ring_info *cpr,
+			       struct sk_buff *skb,
 			       struct skb_shared_info *shinfo,
 			       u16 idx, u32 agg_bufs, bool tpa,
 			       struct xdp_buff *xdp)
@@ -1211,7 +1229,7 @@ static u32 __bnxt_rx_agg_pages(struct bnxt *bp,
 		u16 cons, frag_len;
 		struct rx_agg_cmp *agg;
 		struct bnxt_sw_rx_agg_bd *cons_rx_buf;
-		struct page *page;
+		netmem_ref netmem;
 		dma_addr_t mapping;
 
 		if (p5_tpa)
@@ -1223,9 +1241,15 @@ static u32 __bnxt_rx_agg_pages(struct bnxt *bp,
 			    RX_AGG_CMP_LEN) >> RX_AGG_CMP_LEN_SHIFT;
 
 		cons_rx_buf = &rxr->rx_agg_ring[cons];
-		skb_frag_fill_page_desc(frag, cons_rx_buf->page,
-					cons_rx_buf->offset, frag_len);
-		shinfo->nr_frags = i + 1;
+		if (skb) {
+			skb_add_rx_frag_netmem(skb, i, cons_rx_buf->netmem,
+					       cons_rx_buf->offset, frag_len,
+					       BNXT_RX_PAGE_SIZE);
+		} else {
+			skb_frag_fill_page_desc(frag, netmem_to_page(cons_rx_buf->netmem),
+						cons_rx_buf->offset, frag_len);
+			shinfo->nr_frags = i + 1;
+		}
 		__clear_bit(cons, rxr->rx_agg_bmap);
 
 		/* It is possible for bnxt_alloc_rx_page() to allocate
@@ -1233,15 +1257,15 @@ static u32 __bnxt_rx_agg_pages(struct bnxt *bp,
 		 * need to clear the cons entry now.
 		 */
 		mapping = cons_rx_buf->mapping;
-		page = cons_rx_buf->page;
-		cons_rx_buf->page = NULL;
+		netmem = cons_rx_buf->netmem;
+		cons_rx_buf->netmem = 0;
 
-		if (xdp && page_is_pfmemalloc(page))
+		if (xdp && page_is_pfmemalloc(netmem_to_page(netmem)))
 			xdp_buff_set_frag_pfmemalloc(xdp);
 
-		if (bnxt_alloc_rx_page(bp, rxr, prod, GFP_ATOMIC) != 0) {
+		if (bnxt_alloc_rx_netmem(bp, rxr, prod, GFP_ATOMIC) != 0) {
 			--shinfo->nr_frags;
-			cons_rx_buf->page = page;
+			cons_rx_buf->netmem = netmem;
 
 			/* Update prod since possibly some pages have been
 			 * allocated already.
@@ -1269,7 +1293,7 @@ static struct sk_buff *bnxt_rx_agg_pages_skb(struct bnxt *bp,
 	struct skb_shared_info *shinfo = skb_shinfo(skb);
 	u32 total_frag_len = 0;
 
-	total_frag_len = __bnxt_rx_agg_pages(bp, cpr, shinfo, idx,
+	total_frag_len = __bnxt_rx_agg_pages(bp, cpr, skb, shinfo, idx,
 					     agg_bufs, tpa, NULL);
 	if (!total_frag_len) {
 		skb_mark_for_recycle(skb);
@@ -1277,9 +1301,6 @@ static struct sk_buff *bnxt_rx_agg_pages_skb(struct bnxt *bp,
 		return NULL;
 	}
 
-	skb->data_len += total_frag_len;
-	skb->len += total_frag_len;
-	skb->truesize += BNXT_RX_PAGE_SIZE * agg_bufs;
 	return skb;
 }
 
@@ -1294,7 +1315,7 @@ static u32 bnxt_rx_agg_pages_xdp(struct bnxt *bp,
 	if (!xdp_buff_has_frags(xdp))
 		shinfo->nr_frags = 0;
 
-	total_frag_len = __bnxt_rx_agg_pages(bp, cpr, shinfo,
+	total_frag_len = __bnxt_rx_agg_pages(bp, cpr, NULL, shinfo,
 					     idx, agg_bufs, tpa, xdp);
 	if (total_frag_len) {
 		xdp_buff_set_frags_flag(xdp);
@@ -3342,15 +3363,15 @@ static void bnxt_free_one_rx_agg_ring(struct bnxt *bp, struct bnxt_rx_ring_info
 
 	for (i = 0; i < max_idx; i++) {
 		struct bnxt_sw_rx_agg_bd *rx_agg_buf = &rxr->rx_agg_ring[i];
-		struct page *page = rx_agg_buf->page;
+		netmem_ref netmem = rx_agg_buf->netmem;
 
-		if (!page)
+		if (!netmem)
 			continue;
 
-		rx_agg_buf->page = NULL;
+		rx_agg_buf->netmem = 0;
 		__clear_bit(i, rxr->rx_agg_bmap);
 
-		page_pool_recycle_direct(rxr->page_pool, page);
+		page_pool_put_full_netmem(rxr->page_pool, netmem, true);
 	}
 }
 
@@ -3608,9 +3629,11 @@ static void bnxt_free_rx_rings(struct bnxt *bp)
 
 static int bnxt_alloc_rx_page_pool(struct bnxt *bp,
 				   struct bnxt_rx_ring_info *rxr,
+				   int queue_idx,
 				   int numa_node)
 {
 	struct page_pool_params pp = { 0 };
+	struct netdev_rx_queue *rxq;
 
 	pp.pool_size = bp->rx_agg_ring_size;
 	if (BNXT_RX_PAGE_MODE(bp))
@@ -3621,8 +3644,15 @@ static int bnxt_alloc_rx_page_pool(struct bnxt *bp,
 	pp.dev = &bp->pdev->dev;
 	pp.dma_dir = bp->rx_dir;
 	pp.max_len = PAGE_SIZE;
-	pp.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV;
+	pp.order = 0;
+
+	rxq = __netif_get_rx_queue(bp->dev, queue_idx);
+	if (rxq->mp_params.mp_priv)
+		pp.flags = PP_FLAG_DMA_MAP | PP_FLAG_ALLOW_UNREADABLE_NETMEM;
+	else
+		pp.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV;
 
+	pp.queue_idx = queue_idx;
 	rxr->page_pool = page_pool_create(&pp);
 	if (IS_ERR(rxr->page_pool)) {
 		int err = PTR_ERR(rxr->page_pool);
@@ -3655,7 +3685,7 @@ static int bnxt_alloc_rx_rings(struct bnxt *bp)
 		cpu_node = cpu_to_node(cpu);
 		netdev_dbg(bp->dev, "Allocating page pool for rx_ring[%d] on numa_node: %d\n",
 			   i, cpu_node);
-		rc = bnxt_alloc_rx_page_pool(bp, rxr, cpu_node);
+		rc = bnxt_alloc_rx_page_pool(bp, rxr, i, cpu_node);
 		if (rc)
 			return rc;
 
@@ -4154,7 +4184,7 @@ static void bnxt_alloc_one_rx_ring_page(struct bnxt *bp,
 
 	prod = rxr->rx_agg_prod;
 	for (i = 0; i < bp->rx_agg_ring_size; i++) {
-		if (bnxt_alloc_rx_page(bp, rxr, prod, GFP_KERNEL)) {
+		if (bnxt_alloc_rx_netmem(bp, rxr, prod, GFP_KERNEL)) {
 			netdev_warn(bp->dev, "init'ed rx ring %d with %d/%d pages only\n",
 				    ring_nr, i, bp->rx_ring_size);
 			break;
@@ -15063,7 +15093,7 @@ static int bnxt_queue_mem_alloc(struct net_device *dev, void *qmem, int idx)
 	clone->rx_sw_agg_prod = 0;
 	clone->rx_next_cons = 0;
 
-	rc = bnxt_alloc_rx_page_pool(bp, clone, rxr->page_pool->p.nid);
+	rc = bnxt_alloc_rx_page_pool(bp, clone, idx, rxr->page_pool->p.nid);
 	if (rc)
 		return rc;
 
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 48f390519c35..3cf57a3c7664 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -895,7 +895,7 @@ struct bnxt_sw_rx_bd {
 };
 
 struct bnxt_sw_rx_agg_bd {
-	struct page		*page;
+	netmem_ref		netmem;
 	unsigned int		offset;
 	dma_addr_t		mapping;
 };
-- 
2.34.1