Commit 568a3fa2 authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by David S. Miller
Browse files

net: mvneta: introduce page pool API for sw buffer manager



Use the page_pool api for allocations and DMA handling instead of
__dev_alloc_page()/dma_map_page() and free_page()/dma_unmap_page().
Pages are unmapped using page_pool_release_page before packets
go into the network stack.

The page_pool API offers buffer recycling capabilities for XDP but
allocates one page per packet, unless the driver splits and manages
the allocated page.
This is a preliminary patch to add XDP support to mvneta driver

Signed-off-by: default avatarIlias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ff519e2a
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+1 −0
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ config MVNETA
	depends on ARCH_MVEBU || COMPILE_TEST
	select MVMDIO
	select PHYLINK
	select PAGE_POOL
	---help---
	  This driver supports the network interface units in the
	  Marvell ARMADA XP, ARMADA 370, ARMADA 38x and
+64 −19
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/tso.h>
#include <net/page_pool.h>

/* Registers */
#define MVNETA_RXQ_CONFIG_REG(q)                (0x1400 + ((q) << 2))
@@ -603,6 +604,10 @@ struct mvneta_rx_queue {
	u32 pkts_coal;
	u32 time_coal;

	/* page_pool */
	struct page_pool *page_pool;
	struct xdp_rxq_info xdp_rxq;

	/* Virtual address of the RX buffer */
	void  **buf_virt_addr;

@@ -1812,23 +1817,21 @@ static int mvneta_rx_refill(struct mvneta_port *pp,
			    struct mvneta_rx_queue *rxq,
			    gfp_t gfp_mask)
{
	enum dma_data_direction dma_dir;
	dma_addr_t phys_addr;
	struct page *page;

	page = __dev_alloc_page(gfp_mask);
	page = page_pool_alloc_pages(rxq->page_pool,
				     gfp_mask | __GFP_NOWARN);
	if (!page)
		return -ENOMEM;

	/* map page for use */
	phys_addr = dma_map_page(pp->dev->dev.parent, page, 0, PAGE_SIZE,
				 DMA_FROM_DEVICE);
	if (unlikely(dma_mapping_error(pp->dev->dev.parent, phys_addr))) {
		__free_page(page);
		return -ENOMEM;
	}

	phys_addr += pp->rx_offset_correction;
	phys_addr = page_pool_get_dma_addr(page) + pp->rx_offset_correction;
	dma_dir = page_pool_get_dma_dir(rxq->page_pool);
	dma_sync_single_for_device(pp->dev->dev.parent, phys_addr,
				   PAGE_SIZE, dma_dir);
	mvneta_rx_desc_fill(rx_desc, phys_addr, page, rxq);

	return 0;
}

@@ -1894,10 +1897,12 @@ static void mvneta_rxq_drop_pkts(struct mvneta_port *pp,
		if (!data || !(rx_desc->buf_phys_addr))
			continue;

		dma_unmap_page(pp->dev->dev.parent, rx_desc->buf_phys_addr,
			       PAGE_SIZE, DMA_FROM_DEVICE);
		__free_page(data);
		page_pool_put_page(rxq->page_pool, data, false);
	}
	if (xdp_rxq_info_is_reg(&rxq->xdp_rxq))
		xdp_rxq_info_unreg(&rxq->xdp_rxq);
	page_pool_destroy(rxq->page_pool);
	rxq->page_pool = NULL;
}

static void
@@ -2029,8 +2034,7 @@ static int mvneta_rx_swbm(struct napi_struct *napi,
				skb_add_rx_frag(rxq->skb, frag_num, page,
						frag_offset, frag_size,
						PAGE_SIZE);
				dma_unmap_page(dev->dev.parent, phys_addr,
					       PAGE_SIZE, DMA_FROM_DEVICE);
				page_pool_release_page(rxq->page_pool, page);
				rxq->left_size -= frag_size;
			}
		} else {
@@ -2060,9 +2064,7 @@ static int mvneta_rx_swbm(struct napi_struct *napi,
						frag_offset, frag_size,
						PAGE_SIZE);

				dma_unmap_page(dev->dev.parent, phys_addr,
					       PAGE_SIZE, DMA_FROM_DEVICE);

				page_pool_release_page(rxq->page_pool, page);
				rxq->left_size -= frag_size;
			}
		} /* Middle or Last descriptor */
@@ -2831,11 +2833,54 @@ static int mvneta_poll(struct napi_struct *napi, int budget)
	return rx_done;
}

static int mvneta_create_page_pool(struct mvneta_port *pp,
				   struct mvneta_rx_queue *rxq, int size)
{
	struct page_pool_params pp_params = {
		.order = 0,
		.flags = PP_FLAG_DMA_MAP,
		.pool_size = size,
		.nid = cpu_to_node(0),
		.dev = pp->dev->dev.parent,
		.dma_dir = DMA_FROM_DEVICE,
	};
	int err;

	rxq->page_pool = page_pool_create(&pp_params);
	if (IS_ERR(rxq->page_pool)) {
		err = PTR_ERR(rxq->page_pool);
		rxq->page_pool = NULL;
		return err;
	}

	err = xdp_rxq_info_reg(&rxq->xdp_rxq, pp->dev, rxq->id);
	if (err < 0)
		goto err_free_pp;

	err = xdp_rxq_info_reg_mem_model(&rxq->xdp_rxq, MEM_TYPE_PAGE_POOL,
					 rxq->page_pool);
	if (err)
		goto err_unregister_rxq;

	return 0;

err_unregister_rxq:
	xdp_rxq_info_unreg(&rxq->xdp_rxq);
err_free_pp:
	page_pool_destroy(rxq->page_pool);
	rxq->page_pool = NULL;
	return err;
}

/* Handle rxq fill: allocates rxq skbs; called when initializing a port */
static int mvneta_rxq_fill(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
			   int num)
{
	int i;
	int i, err;

	err = mvneta_create_page_pool(pp, rxq, num);
	if (err < 0)
		return err;

	for (i = 0; i < num; i++) {
		memset(rxq->descs + i, 0, sizeof(struct mvneta_rx_desc));