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: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Lorenzo Bianconi 2019-10-19 10:13:22 +02:00 committed by David S. Miller
parent ff519e2acd
commit 568a3fa24a
2 changed files with 65 additions and 19 deletions

View File

@ -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

View File

@ -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));