Current driver dynamically allocates an skb and maps it as DMA rx buffer.
A following patch introduces XDP functionality, so we need a
different allocation scheme. Buffers are allocated dynamically and
mapped into hardware. During the Rx operation the driver uses
build_skb() to produce the necessary buffers for the network stack
Signed-off-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>
---
drivers/net/ethernet/socionext/netsec.c | 238 +++++++++++++++++---------------
1 file changed, 129 insertions(+), 109 deletions(-)
diff --git a/drivers/net/ethernet/socionext/netsec.c
b/drivers/net/ethernet/socionext/netsec.c
index 7aa5ebb..8f788a1 100644
--- a/drivers/net/ethernet/socionext/netsec.c
+++ b/drivers/net/ethernet/socionext/netsec.c
@@ -296,6 +296,11 @@ struct netsec_rx_pkt_info {
bool err_flag;
};
+static void netsec_rx_fill(struct netsec_priv *priv, u16 from, u16 num);
+
+static void *netsec_alloc_rx_data(struct netsec_priv *priv,
+ dma_addr_t *dma_addr, u16 *len);
+
static void netsec_write(struct netsec_priv *priv, u32 reg_addr, u32 val)
{
writel(val, priv->ioaddr + reg_addr);
@@ -556,34 +561,10 @@ static const struct ethtool_ops netsec_ethtool_ops = {
/************* NETDEV_OPS FOLLOW *************/
-static struct sk_buff *netsec_alloc_skb(struct netsec_priv *priv,
- struct netsec_desc *desc)
-{
- struct sk_buff *skb;
-
- if (device_get_dma_attr(priv->dev) == DEV_DMA_COHERENT) {
- skb = netdev_alloc_skb_ip_align(priv->ndev, desc->len);
- } else {
- desc->len = L1_CACHE_ALIGN(desc->len);
- skb = netdev_alloc_skb(priv->ndev, desc->len);
- }
- if (!skb)
- return NULL;
-
- desc->addr = skb->data;
- desc->dma_addr = dma_map_single(priv->dev, desc->addr, desc->len,
- DMA_FROM_DEVICE);
- if (dma_mapping_error(priv->dev, desc->dma_addr)) {
- dev_kfree_skb_any(skb);
- return NULL;
- }
- return skb;
-}
static void netsec_set_rx_de(struct netsec_priv *priv,
struct netsec_desc_ring *dring, u16 idx,
- const struct netsec_desc *desc,
- struct sk_buff *skb)
+ const struct netsec_desc *desc)
{
struct netsec_de *de = dring->vaddr + DESC_SZ * idx;
u32 attr = (1 << NETSEC_RX_PKT_OWN_FIELD) |
@@ -602,59 +583,6 @@ static void netsec_set_rx_de(struct netsec_priv *priv,
dring->desc[idx].dma_addr = desc->dma_addr;
dring->desc[idx].addr = desc->addr;
dring->desc[idx].len = desc->len;
- dring->desc[idx].skb = skb;
-}
-
-static struct sk_buff *netsec_get_rx_de(struct netsec_priv *priv,
- struct netsec_desc_ring *dring,
- u16 idx,
- struct netsec_rx_pkt_info *rxpi,
- struct netsec_desc *desc, u16 *len)
-{
- struct netsec_de de = {};
-
- memcpy(&de, dring->vaddr + DESC_SZ * idx, DESC_SZ);
-
- *len = de.buf_len_info >> 16;
-
- rxpi->err_flag = (de.attr >> NETSEC_RX_PKT_ER_FIELD) & 1;
- rxpi->rx_cksum_result = (de.attr >> NETSEC_RX_PKT_CO_FIELD) & 3;
- rxpi->err_code = (de.attr >> NETSEC_RX_PKT_ERR_FIELD) &
- NETSEC_RX_PKT_ERR_MASK;
- *desc = dring->desc[idx];
- return desc->skb;
-}
-
-static struct sk_buff *netsec_get_rx_pkt_data(struct netsec_priv *priv,
- struct netsec_rx_pkt_info *rxpi,
- struct netsec_desc *desc,
- u16 *len)
-{
- struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_RX];
- struct sk_buff *tmp_skb, *skb = NULL;
- struct netsec_desc td;
- int tail;
-
- *rxpi = (struct netsec_rx_pkt_info){};
-
- td.len = priv->ndev->mtu + 22;
-
- tmp_skb = netsec_alloc_skb(priv, &td);
-
- tail = dring->tail;
-
- if (!tmp_skb) {
- netsec_set_rx_de(priv, dring, tail, &dring->desc[tail],
- dring->desc[tail].skb);
- } else {
- skb = netsec_get_rx_de(priv, dring, tail, rxpi, desc, len);
- netsec_set_rx_de(priv, dring, tail, &td, tmp_skb);
- }
-
- /* move tail ahead */
- dring->tail = (dring->tail + 1) % DESC_NUM;
-
- return skb;
}
static int netsec_clean_tx_dring(struct netsec_priv *priv, int budget)
@@ -721,19 +649,28 @@ static int netsec_process_tx(struct netsec_priv *priv,
int budget)
return done;
}
+static void netsec_adv_desc(u16 *idx)
+{
+ *idx = *idx + 1;
+ if (unlikely(*idx >= DESC_NUM))
+ *idx = 0;
+}
+
static int netsec_process_rx(struct netsec_priv *priv, int budget)
{
struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_RX];
struct net_device *ndev = priv->ndev;
- struct netsec_rx_pkt_info rx_info;
- int done = 0;
- struct netsec_desc desc;
struct sk_buff *skb;
- u16 len;
+ int done = 0;
while (done < budget) {
u16 idx = dring->tail;
struct netsec_de *de = dring->vaddr + (DESC_SZ * idx);
+ struct netsec_desc *desc = &dring->desc[idx];
+ struct netsec_rx_pkt_info rpi;
+ u16 pkt_len, desc_len;
+ dma_addr_t dma_handle;
+ void *buf_addr;
if (de->attr & (1U << NETSEC_RX_PKT_OWN_FIELD))
break;
@@ -744,28 +681,62 @@ static int netsec_process_rx(struct netsec_priv *priv,
int budget)
*/
dma_rmb();
done++;
- skb = netsec_get_rx_pkt_data(priv, &rx_info, &desc, &len);
- if (unlikely(!skb) || rx_info.err_flag) {
+
+ pkt_len = de->buf_len_info >> 16;
+ rpi.err_code = (de->attr >> NETSEC_RX_PKT_ERR_FIELD) &
+ NETSEC_RX_PKT_ERR_MASK;
+ rpi.err_flag = (de->attr >> NETSEC_RX_PKT_ER_FIELD) & 1;
+ if (rpi.err_flag) {
netif_err(priv, drv, priv->ndev,
- "%s: rx fail err(%d)\n",
- __func__, rx_info.err_code);
+ "%s: rx fail err(%d)\n", __func__,
+ rpi.err_code);
ndev->stats.rx_dropped++;
+ netsec_adv_desc(&dring->tail);
+ /* reuse buffer page frag */
+ netsec_rx_fill(priv, idx, 1);
continue;
}
+ rpi.rx_cksum_result = (de->attr >> NETSEC_RX_PKT_CO_FIELD) & 3;
- dma_unmap_single(priv->dev, desc.dma_addr, desc.len,
- DMA_FROM_DEVICE);
- skb_put(skb, len);
+ buf_addr = netsec_alloc_rx_data(priv, &dma_handle, &desc_len);
+ if (unlikely(!buf_addr))
+ break;
+
+ dma_sync_single_for_cpu(priv->dev, desc->dma_addr, pkt_len,
+ DMA_FROM_DEVICE);
+ prefetch(desc->addr);
+
+ skb = build_skb(desc->addr, desc->len);
+ if (unlikely(!skb)) {
+ dma_unmap_single(priv->dev, dma_handle, desc_len,
+ DMA_TO_DEVICE);
+ skb_free_frag(buf_addr);
+ netif_err(priv, drv, priv->ndev,
+ "rx failed to alloc skb\n");
+ break;
+ }
+ dma_unmap_single_attrs(priv->dev, desc->dma_addr, desc->len,
+ DMA_TO_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
+
+ /* Update the descriptor with fresh buffers */
+ desc->len = desc_len;
+ desc->dma_addr = dma_handle;
+ desc->addr = buf_addr;
+
+ skb_put(skb, pkt_len);
skb->protocol = eth_type_trans(skb, priv->ndev);
if (priv->rx_cksum_offload_flag &&
- rx_info.rx_cksum_result == NETSEC_RX_CKSUM_OK)
+ rpi.rx_cksum_result == NETSEC_RX_CKSUM_OK)
skb->ip_summed = CHECKSUM_UNNECESSARY;
if (napi_gro_receive(&priv->napi, skb) != GRO_DROP) {
ndev->stats.rx_packets++;
- ndev->stats.rx_bytes += len;
+ ndev->stats.rx_bytes += pkt_len;
}
+
+ netsec_rx_fill(priv, idx, 1);
+ netsec_adv_desc(&dring->tail);
}
return done;
@@ -928,7 +899,10 @@ static void netsec_uninit_pkt_dring(struct netsec_priv
*priv, int id)
dma_unmap_single(priv->dev, desc->dma_addr, desc->len,
id == NETSEC_RING_RX ? DMA_FROM_DEVICE :
DMA_TO_DEVICE);
- dev_kfree_skb(desc->skb);
+ if (id == NETSEC_RING_RX)
+ skb_free_frag(desc->addr);
+ else if (id == NETSEC_RING_TX)
+ dev_kfree_skb(desc->skb);
}
memset(dring->desc, 0, sizeof(struct netsec_desc) * DESC_NUM);
@@ -953,50 +927,96 @@ static void netsec_free_dring(struct netsec_priv *priv,
int id)
dring->desc = NULL;
}
+static void *netsec_alloc_rx_data(struct netsec_priv *priv,
+ dma_addr_t *dma_handle, u16 *desc_len)
+{
+ size_t len = priv->ndev->mtu + ETH_HLEN + 2 * VLAN_HLEN + NET_SKB_PAD +
+ NET_IP_ALIGN;
+ dma_addr_t mapping;
+ void *buf;
+
+ len += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ len = SKB_DATA_ALIGN(len);
+
+ buf = napi_alloc_frag(len);
+ if (!buf)
+ return NULL;
+
+ mapping = dma_map_single(priv->dev, buf, len, DMA_FROM_DEVICE);
+ if (unlikely(dma_mapping_error(priv->dev, mapping)))
+ goto err_out;
+
+ *dma_handle = mapping;
+ *desc_len = len;
+
+ return buf;
+
+err_out:
+ skb_free_frag(buf);
+ return NULL;
+}
+
+static void netsec_rx_fill(struct netsec_priv *priv, u16 from, u16 num)
+{
+ struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_RX];
+ u16 idx = from;
+
+ while (num) {
+ netsec_set_rx_de(priv, dring, idx, &dring->desc[idx]);
+ idx++;
+ if (idx >= DESC_NUM)
+ idx = 0;
+ num--;
+ }
+}
+
static int netsec_alloc_dring(struct netsec_priv *priv, enum ring_id id)
{
struct netsec_desc_ring *dring = &priv->desc_ring[id];
- int ret = 0;
dring->vaddr = dma_zalloc_coherent(priv->dev, DESC_SZ * DESC_NUM,
&dring->desc_dma, GFP_KERNEL);
- if (!dring->vaddr) {
- ret = -ENOMEM;
+ if (!dring->vaddr)
goto err;
- }
dring->desc = kcalloc(DESC_NUM, sizeof(*dring->desc), GFP_KERNEL);
- if (!dring->desc) {
- ret = -ENOMEM;
+ if (!dring->desc)
goto err;
- }
return 0;
err:
netsec_free_dring(priv, id);
- return ret;
+ return -ENOMEM;
}
static int netsec_setup_rx_dring(struct netsec_priv *priv)
{
struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_RX];
- struct netsec_desc desc;
- struct sk_buff *skb;
- int n;
+ int i;
- desc.len = priv->ndev->mtu + 22;
+ for (i = 0; i < DESC_NUM; i++) {
+ struct netsec_desc *desc = &dring->desc[i];
+ dma_addr_t dma_handle;
+ void *buf;
+ u16 len;
- for (n = 0; n < DESC_NUM; n++) {
- skb = netsec_alloc_skb(priv, &desc);
- if (!skb) {
+ buf = netsec_alloc_rx_data(priv, &dma_handle, &len);
+ if (!buf) {
netsec_uninit_pkt_dring(priv, NETSEC_RING_RX);
- return -ENOMEM;
+ goto err_out;
}
- netsec_set_rx_de(priv, dring, n, &desc, skb);
+ desc->dma_addr = dma_handle;
+ desc->addr = buf;
+ desc->len = len;
}
+ netsec_rx_fill(priv, 0, DESC_NUM);
+
return 0;
+
+err_out:
+ return -ENOMEM;
}
static int netsec_netdev_load_ucode_region(struct netsec_priv *priv, u32 reg,
--
2.7.4
