[PATCH net-next 4/6] net: mvneta: Allocate page for the descriptor

From: Gregory CLEMENT
Date: Fri Jul 06 2018 - 09:21:10 EST


Instead of trying to allocate the exact amount of memory for each
descriptor use a page for each of them, it allows to simplify the
allocation management and increase the performance of the driver.

Based on the work of Yelena Krivosheev <yelena@xxxxxxxxxxx>
Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>
---
drivers/net/ethernet/marvell/mvneta.c | 66 ++++++++++--------------
drivers/net/ethernet/marvell/mvneta_bm.h | 3 --
2 files changed, 26 insertions(+), 43 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 2c575c6732ce..12739fb60732 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -1791,47 +1791,30 @@ static void mvneta_txq_done(struct mvneta_port *pp,
}
}

-void *mvneta_frag_alloc(unsigned int frag_size)
-{
- if (likely(frag_size <= PAGE_SIZE))
- return netdev_alloc_frag(frag_size);
- else
- return kmalloc(frag_size, GFP_ATOMIC);
-}
-EXPORT_SYMBOL_GPL(mvneta_frag_alloc);
-
-void mvneta_frag_free(unsigned int frag_size, void *data)
-{
- if (likely(frag_size <= PAGE_SIZE))
- skb_free_frag(data);
- else
- kfree(data);
-}
-EXPORT_SYMBOL_GPL(mvneta_frag_free);
-
/* Refill processing for SW buffer management */
-static int mvneta_rx_refill(struct mvneta_port *pp,
- struct mvneta_rx_desc *rx_desc,
- struct mvneta_rx_queue *rxq)
-
+/* Allocate page per descriptor */
+static inline int mvneta_rx_refill(struct mvneta_port *pp,
+ struct mvneta_rx_desc *rx_desc,
+ struct mvneta_rx_queue *rxq,
+ gfp_t gfp_mask)
{
dma_addr_t phys_addr;
- void *data;
+ struct page *page;

- data = mvneta_frag_alloc(pp->frag_size);
- if (!data)
+ page = __dev_alloc_page(gfp_mask);
+ if (!page)
return -ENOMEM;

- phys_addr = dma_map_single(pp->dev->dev.parent, data,
- MVNETA_RX_BUF_SIZE(pp->pkt_size),
- DMA_FROM_DEVICE);
+ /* 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))) {
- mvneta_frag_free(pp->frag_size, data);
+ __free_page(page);
return -ENOMEM;
}

phys_addr += pp->rx_offset_correction;
- mvneta_rx_desc_fill(rx_desc, phys_addr, data, rxq);
+ mvneta_rx_desc_fill(rx_desc, phys_addr, page, rxq);
return 0;
}

@@ -1897,7 +1880,7 @@ static void mvneta_rxq_drop_pkts(struct mvneta_port *pp,

dma_unmap_single(pp->dev->dev.parent, rx_desc->buf_phys_addr,
MVNETA_RX_BUF_SIZE(pp->pkt_size), DMA_FROM_DEVICE);
- mvneta_frag_free(pp->frag_size, data);
+ __free_page(data);
}
}

@@ -1924,6 +1907,7 @@ static int mvneta_rx_swbm(struct mvneta_port *pp, int rx_todo,
struct mvneta_rx_desc *rx_desc = mvneta_rxq_next_desc_get(rxq);
struct sk_buff *skb;
unsigned char *data;
+ struct page *page;
dma_addr_t phys_addr;
u32 rx_status, frag_size;
int rx_bytes, err, index;
@@ -1932,7 +1916,10 @@ static int mvneta_rx_swbm(struct mvneta_port *pp, int rx_todo,
rx_status = rx_desc->status;
rx_bytes = rx_desc->data_size - (ETH_FCS_LEN + MVNETA_MH_SIZE);
index = rx_desc - rxq->descs;
- data = rxq->buf_virt_addr[index];
+ page = (struct page *)rxq->buf_virt_addr[index];
+ data = page_address(page);
+ /* Prefetch header */
+ prefetch(data);
phys_addr = rx_desc->buf_phys_addr - pp->rx_offset_correction;

if (!mvneta_rxq_desc_is_first_last(rx_status) ||
@@ -1975,7 +1962,7 @@ static int mvneta_rx_swbm(struct mvneta_port *pp, int rx_todo,
}

/* Refill processing */
- err = mvneta_rx_refill(pp, rx_desc, rxq);
+ err = mvneta_rx_refill(pp, rx_desc, rxq, GFP_KERNEL);
if (err) {
netdev_err(dev, "Linux processing - Can't refill\n");
rxq->refill_err++;
@@ -2767,9 +2754,11 @@ static int mvneta_rxq_fill(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,

for (i = 0; i < num; i++) {
memset(rxq->descs + i, 0, sizeof(struct mvneta_rx_desc));
- if (mvneta_rx_refill(pp, rxq->descs + i, rxq) != 0) {
- netdev_err(pp->dev, "%s:rxq %d, %d of %d buffs filled\n",
- __func__, rxq->id, i, num);
+ if (mvneta_rx_refill(pp, rxq->descs + i, rxq,
+ GFP_KERNEL) != 0) {
+ netdev_err(pp->dev,
+ "%s:rxq %d, %d of %d buffs filled\n",
+ __func__, rxq->id, i, num);
break;
}
}
@@ -3183,8 +3172,6 @@ static int mvneta_change_mtu(struct net_device *dev, int mtu)
mvneta_bm_update_mtu(pp, mtu);

pp->pkt_size = MVNETA_RX_PKT_SIZE(dev->mtu);
- pp->frag_size = SKB_DATA_ALIGN(MVNETA_RX_BUF_SIZE(pp->pkt_size)) +
- SKB_DATA_ALIGN(sizeof(struct skb_shared_info));

ret = mvneta_setup_rxqs(pp);
if (ret) {
@@ -3672,8 +3659,7 @@ static int mvneta_open(struct net_device *dev)
int ret;

pp->pkt_size = MVNETA_RX_PKT_SIZE(pp->dev->mtu);
- pp->frag_size = SKB_DATA_ALIGN(MVNETA_RX_BUF_SIZE(pp->pkt_size)) +
- SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ pp->frag_size = PAGE_SIZE;

ret = mvneta_setup_rxqs(pp);
if (ret)
diff --git a/drivers/net/ethernet/marvell/mvneta_bm.h b/drivers/net/ethernet/marvell/mvneta_bm.h
index 9358626e51ec..c8425d35c049 100644
--- a/drivers/net/ethernet/marvell/mvneta_bm.h
+++ b/drivers/net/ethernet/marvell/mvneta_bm.h
@@ -130,9 +130,6 @@ struct mvneta_bm_pool {
};

/* Declarations and definitions */
-void *mvneta_frag_alloc(unsigned int frag_size);
-void mvneta_frag_free(unsigned int frag_size, void *data);
-
#if IS_ENABLED(CONFIG_MVNETA_BM)
struct mvneta_bm *mvneta_bm_get(struct device_node *node);
void mvneta_bm_put(struct mvneta_bm *priv);
--
2.17.1