This patch series aim to improve the bcm63xx_enet driver by integrating the
latest networking features, i.e. batched rx processing, BQL, build_skb, etc.
The newer enetsw SoCs are found to be able to do unaligned rx DMA by adding
NET_IP_ALIGN padding which, combined with these patches, improved packet
processing performance by ~50% on BCM6328.
Older non-enetsw SoCs still benefit mainly from rx batching. Performance
improvement of ~30% is observed on BCM6333.
The BCM63xx SoCs are designed for routers. As such, having BQL is beneficial
as well as trivial to add.
v2:
* Add xmit_more support and rx loop improvisation patches.
* Moved BQL netdev_reset_queue() to bcm_enet_stop()/bcm_enetsw_stop()
functions as suggested by Florian Fainelli.
* Improved commit messages.
Sieng Piaw Liew (6):
bcm63xx_enet: batch process rx path
bcm63xx_enet: add BQL support
bcm63xx_enet: add xmit_more support
bcm63xx_enet: alloc rx skb with NET_IP_ALIGN
bcm63xx_enet: convert to build_skb
bcm63xx_enet: improve rx loop
drivers/net/ethernet/broadcom/bcm63xx_enet.c | 184 ++++++++++---------
drivers/net/ethernet/broadcom/bcm63xx_enet.h | 14 +-
2 files changed, 103 insertions(+), 95 deletions(-)
--
2.17.1
Add Byte Queue Limits support to reduce/remove bufferbloat in
bcm63xx_enet.
Signed-off-by: Sieng Piaw Liew <[email protected]>
---
drivers/net/ethernet/broadcom/bcm63xx_enet.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/net/ethernet/broadcom/bcm63xx_enet.c b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
index b82b7805c36a..90f8214b4d22 100644
--- a/drivers/net/ethernet/broadcom/bcm63xx_enet.c
+++ b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
@@ -417,9 +417,11 @@ static int bcm_enet_receive_queue(struct net_device *dev, int budget)
static int bcm_enet_tx_reclaim(struct net_device *dev, int force)
{
struct bcm_enet_priv *priv;
+ unsigned int bytes;
int released;
priv = netdev_priv(dev);
+ bytes = 0;
released = 0;
while (priv->tx_desc_count < priv->tx_ring_size) {
@@ -456,10 +458,13 @@ static int bcm_enet_tx_reclaim(struct net_device *dev, int force)
if (desc->len_stat & DMADESC_UNDER_MASK)
dev->stats.tx_errors++;
+ bytes += skb->len;
dev_kfree_skb(skb);
released++;
}
+ netdev_completed_queue(dev, released, bytes);
+
if (netif_queue_stopped(dev) && released)
netif_wake_queue(dev);
@@ -626,6 +631,8 @@ bcm_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
desc->len_stat = len_stat;
wmb();
+ netdev_sent_queue(dev, skb->len);
+
/* kick tx dma */
enet_dmac_writel(priv, priv->dma_chan_en_mask,
ENETDMAC_CHANCFG, priv->tx_chan);
@@ -1169,6 +1176,7 @@ static int bcm_enet_stop(struct net_device *dev)
kdev = &priv->pdev->dev;
netif_stop_queue(dev);
+ netdev_reset_queue(dev);
napi_disable(&priv->napi);
if (priv->has_phy)
phy_stop(dev->phydev);
@@ -2338,6 +2346,7 @@ static int bcm_enetsw_stop(struct net_device *dev)
del_timer_sync(&priv->swphy_poll);
netif_stop_queue(dev);
+ netdev_reset_queue(dev);
napi_disable(&priv->napi);
del_timer_sync(&priv->rx_timeout);
--
2.17.1
Use existing rx processed count to track against budget, thereby making
budget decrement operation redundant.
rx_desc_count can be calculated outside the rx loop, making the loop a
bit smaller.
Signed-off-by: Sieng Piaw Liew <[email protected]>
---
drivers/net/ethernet/broadcom/bcm63xx_enet.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bcm63xx_enet.c b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
index 8c2e97311a2c..5ff0d39be2b2 100644
--- a/drivers/net/ethernet/broadcom/bcm63xx_enet.c
+++ b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
@@ -339,7 +339,6 @@ static int bcm_enet_receive_queue(struct net_device *dev, int budget)
priv->rx_curr_desc++;
if (priv->rx_curr_desc == priv->rx_ring_size)
priv->rx_curr_desc = 0;
- priv->rx_desc_count--;
/* if the packet does not have start of packet _and_
* end of packet flag set, then just recycle it */
@@ -404,9 +403,10 @@ static int bcm_enet_receive_queue(struct net_device *dev, int budget)
dev->stats.rx_bytes += len;
list_add_tail(&skb->list, &rx_list);
- } while (--budget > 0);
+ } while (processed < budget);
netif_receive_skb_list(&rx_list);
+ priv->rx_desc_count -= processed;
if (processed || !priv->rx_desc_count) {
bcm_enet_refill_rx(dev, true);
--
2.17.1
We can increase the efficiency of rx path by using buffers to receive
packets then build SKBs around them just before passing into the network
stack. In contrast, preallocating SKBs too early reduces CPU cache
efficiency.
Check if we're in NAPI context when refilling RX. Normally we're almost
always running in NAPI context. Dispatch to napi_alloc_frag directly
instead of relying on netdev_alloc_frag which does the same but
with the overhead of local_bh_disable/enable.
Tested on BCM6328 320 MHz and iperf3 -M 512 to measure packet/sec
performance. Included netif_receive_skb_list and NET_IP_ALIGN
optimizations.
Before:
[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-10.00 sec 49.9 MBytes 41.9 Mbits/sec 197 sender
[ 4] 0.00-10.00 sec 49.3 MBytes 41.3 Mbits/sec receiver
After:
[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-30.00 sec 171 MBytes 47.8 Mbits/sec 272 sender
[ 4] 0.00-30.00 sec 170 MBytes 47.6 Mbits/sec receiver
Signed-off-by: Sieng Piaw Liew <[email protected]>
---
drivers/net/ethernet/broadcom/bcm63xx_enet.c | 157 +++++++++----------
drivers/net/ethernet/broadcom/bcm63xx_enet.h | 14 +-
2 files changed, 80 insertions(+), 91 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bcm63xx_enet.c b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
index 51976ed87d2d..8c2e97311a2c 100644
--- a/drivers/net/ethernet/broadcom/bcm63xx_enet.c
+++ b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
@@ -220,7 +220,7 @@ static void bcm_enet_mdio_write_mii(struct net_device *dev, int mii_id,
/*
* refill rx queue
*/
-static int bcm_enet_refill_rx(struct net_device *dev)
+static int bcm_enet_refill_rx(struct net_device *dev, bool napi_mode)
{
struct bcm_enet_priv *priv;
@@ -228,29 +228,29 @@ static int bcm_enet_refill_rx(struct net_device *dev)
while (priv->rx_desc_count < priv->rx_ring_size) {
struct bcm_enet_desc *desc;
- struct sk_buff *skb;
- dma_addr_t p;
int desc_idx;
u32 len_stat;
desc_idx = priv->rx_dirty_desc;
desc = &priv->rx_desc_cpu[desc_idx];
- if (!priv->rx_skb[desc_idx]) {
- if (priv->enet_is_sw)
- skb = netdev_alloc_skb_ip_align(dev, priv->rx_skb_size);
+ if (!priv->rx_buf[desc_idx]) {
+ void *buf;
+
+ if (likely(napi_mode))
+ buf = napi_alloc_frag(priv->rx_frag_size);
else
- skb = netdev_alloc_skb(dev, priv->rx_skb_size);
- if (!skb)
+ buf = netdev_alloc_frag(priv->rx_frag_size);
+ if (unlikely(!buf))
break;
- priv->rx_skb[desc_idx] = skb;
- p = dma_map_single(&priv->pdev->dev, skb->data,
- priv->rx_skb_size,
- DMA_FROM_DEVICE);
- desc->address = p;
+ priv->rx_buf[desc_idx] = buf;
+ desc->address = dma_map_single(&priv->pdev->dev,
+ buf + priv->rx_buf_offset,
+ priv->rx_buf_size,
+ DMA_FROM_DEVICE);
}
- len_stat = priv->rx_skb_size << DMADESC_LENGTH_SHIFT;
+ len_stat = priv->rx_buf_size << DMADESC_LENGTH_SHIFT;
len_stat |= DMADESC_OWNER_MASK;
if (priv->rx_dirty_desc == priv->rx_ring_size - 1) {
len_stat |= (DMADESC_WRAP_MASK >> priv->dma_desc_shift);
@@ -290,7 +290,7 @@ static void bcm_enet_refill_rx_timer(struct timer_list *t)
struct net_device *dev = priv->net_dev;
spin_lock(&priv->rx_lock);
- bcm_enet_refill_rx(dev);
+ bcm_enet_refill_rx(dev, false);
spin_unlock(&priv->rx_lock);
}
@@ -320,6 +320,7 @@ static int bcm_enet_receive_queue(struct net_device *dev, int budget)
int desc_idx;
u32 len_stat;
unsigned int len;
+ void *buf;
desc_idx = priv->rx_curr_desc;
desc = &priv->rx_desc_cpu[desc_idx];
@@ -365,16 +366,14 @@ static int bcm_enet_receive_queue(struct net_device *dev, int budget)
}
/* valid packet */
- skb = priv->rx_skb[desc_idx];
+ buf = priv->rx_buf[desc_idx];
len = (len_stat & DMADESC_LENGTH_MASK) >> DMADESC_LENGTH_SHIFT;
/* don't include FCS */
len -= 4;
if (len < copybreak) {
- struct sk_buff *nskb;
-
- nskb = napi_alloc_skb(&priv->napi, len);
- if (!nskb) {
+ skb = napi_alloc_skb(&priv->napi, len);
+ if (unlikely(!skb)) {
/* forget packet, just rearm desc */
dev->stats.rx_dropped++;
continue;
@@ -382,14 +381,21 @@ static int bcm_enet_receive_queue(struct net_device *dev, int budget)
dma_sync_single_for_cpu(kdev, desc->address,
len, DMA_FROM_DEVICE);
- memcpy(nskb->data, skb->data, len);
+ memcpy(skb->data, buf + priv->rx_buf_offset, len);
dma_sync_single_for_device(kdev, desc->address,
len, DMA_FROM_DEVICE);
- skb = nskb;
} else {
- dma_unmap_single(&priv->pdev->dev, desc->address,
- priv->rx_skb_size, DMA_FROM_DEVICE);
- priv->rx_skb[desc_idx] = NULL;
+ dma_unmap_single(kdev, desc->address,
+ priv->rx_buf_size, DMA_FROM_DEVICE);
+ priv->rx_buf[desc_idx] = NULL;
+
+ skb = build_skb(buf, priv->rx_frag_size);
+ if (unlikely(!skb)) {
+ skb_free_frag(buf);
+ dev->stats.rx_dropped++;
+ continue;
+ }
+ skb_reserve(skb, priv->rx_buf_offset);
}
skb_put(skb, len);
@@ -403,7 +409,7 @@ static int bcm_enet_receive_queue(struct net_device *dev, int budget)
netif_receive_skb_list(&rx_list);
if (processed || !priv->rx_desc_count) {
- bcm_enet_refill_rx(dev);
+ bcm_enet_refill_rx(dev, true);
/* kick rx dma */
enet_dmac_writel(priv, priv->dma_chan_en_mask,
@@ -862,6 +868,24 @@ static void bcm_enet_adjust_link(struct net_device *dev)
priv->pause_tx ? "tx" : "off");
}
+static void bcm_enet_free_rx_buf_ring(struct device *kdev, struct bcm_enet_priv *priv)
+{
+ int i;
+
+ for (i = 0; i < priv->rx_ring_size; i++) {
+ struct bcm_enet_desc *desc;
+
+ if (!priv->rx_buf[i])
+ continue;
+
+ desc = &priv->rx_desc_cpu[i];
+ dma_unmap_single(kdev, desc->address, priv->rx_buf_size,
+ DMA_FROM_DEVICE);
+ skb_free_frag(priv->rx_buf[i]);
+ }
+ kfree(priv->rx_buf);
+}
+
/*
* open callback, allocate dma rings & buffers and start rx operation
*/
@@ -971,10 +995,10 @@ static int bcm_enet_open(struct net_device *dev)
priv->tx_curr_desc = 0;
spin_lock_init(&priv->tx_lock);
- /* init & fill rx ring with skbs */
- priv->rx_skb = kcalloc(priv->rx_ring_size, sizeof(struct sk_buff *),
+ /* init & fill rx ring with buffers */
+ priv->rx_buf = kcalloc(priv->rx_ring_size, sizeof(void *),
GFP_KERNEL);
- if (!priv->rx_skb) {
+ if (!priv->rx_buf) {
ret = -ENOMEM;
goto out_free_tx_skb;
}
@@ -991,7 +1015,7 @@ static int bcm_enet_open(struct net_device *dev)
enet_dmac_writel(priv, ENETDMA_BUFALLOC_FORCE_MASK | 0,
ENETDMAC_BUFALLOC, priv->rx_chan);
- if (bcm_enet_refill_rx(dev)) {
+ if (bcm_enet_refill_rx(dev, false)) {
dev_err(kdev, "cannot allocate rx skb queue\n");
ret = -ENOMEM;
goto out;
@@ -1086,18 +1110,7 @@ static int bcm_enet_open(struct net_device *dev)
return 0;
out:
- for (i = 0; i < priv->rx_ring_size; i++) {
- struct bcm_enet_desc *desc;
-
- if (!priv->rx_skb[i])
- continue;
-
- desc = &priv->rx_desc_cpu[i];
- dma_unmap_single(kdev, desc->address, priv->rx_skb_size,
- DMA_FROM_DEVICE);
- kfree_skb(priv->rx_skb[i]);
- }
- kfree(priv->rx_skb);
+ bcm_enet_free_rx_buf_ring(kdev, priv);
out_free_tx_skb:
kfree(priv->tx_skb);
@@ -1176,7 +1189,6 @@ static int bcm_enet_stop(struct net_device *dev)
{
struct bcm_enet_priv *priv;
struct device *kdev;
- int i;
priv = netdev_priv(dev);
kdev = &priv->pdev->dev;
@@ -1204,21 +1216,10 @@ static int bcm_enet_stop(struct net_device *dev)
/* force reclaim of all tx buffers */
bcm_enet_tx_reclaim(dev, 1);
- /* free the rx skb ring */
- for (i = 0; i < priv->rx_ring_size; i++) {
- struct bcm_enet_desc *desc;
-
- if (!priv->rx_skb[i])
- continue;
-
- desc = &priv->rx_desc_cpu[i];
- dma_unmap_single(kdev, desc->address, priv->rx_skb_size,
- DMA_FROM_DEVICE);
- kfree_skb(priv->rx_skb[i]);
- }
+ /* free the rx buffer ring */
+ bcm_enet_free_rx_buf_ring(kdev, priv);
/* free remaining allocated memory */
- kfree(priv->rx_skb);
kfree(priv->tx_skb);
dma_free_coherent(kdev, priv->rx_desc_alloc_size,
priv->rx_desc_cpu, priv->rx_desc_dma);
@@ -1640,9 +1641,12 @@ static int bcm_enet_change_mtu(struct net_device *dev, int new_mtu)
* align rx buffer size to dma burst len, account FCS since
* it's appended
*/
- priv->rx_skb_size = ALIGN(actual_mtu + ETH_FCS_LEN,
+ priv->rx_buf_size = ALIGN(actual_mtu + ETH_FCS_LEN,
priv->dma_maxburst * 4);
+ priv->rx_frag_size = SKB_DATA_ALIGN(priv->rx_buf_offset + priv->rx_buf_size)
+ + SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
dev->mtu = new_mtu;
return 0;
}
@@ -1727,6 +1731,7 @@ static int bcm_enet_probe(struct platform_device *pdev)
priv->enet_is_sw = false;
priv->dma_maxburst = BCMENET_DMA_MAXBURST;
+ priv->rx_buf_offset = NET_SKB_PAD;
ret = bcm_enet_change_mtu(dev, dev->mtu);
if (ret)
@@ -2154,10 +2159,10 @@ static int bcm_enetsw_open(struct net_device *dev)
priv->tx_curr_desc = 0;
spin_lock_init(&priv->tx_lock);
- /* init & fill rx ring with skbs */
- priv->rx_skb = kcalloc(priv->rx_ring_size, sizeof(struct sk_buff *),
+ /* init & fill rx ring with buffers */
+ priv->rx_buf = kcalloc(priv->rx_ring_size, sizeof(void *),
GFP_KERNEL);
- if (!priv->rx_skb) {
+ if (!priv->rx_buf) {
dev_err(kdev, "cannot allocate rx skb queue\n");
ret = -ENOMEM;
goto out_free_tx_skb;
@@ -2205,7 +2210,7 @@ static int bcm_enetsw_open(struct net_device *dev)
enet_dma_writel(priv, ENETDMA_BUFALLOC_FORCE_MASK | 0,
ENETDMA_BUFALLOC_REG(priv->rx_chan));
- if (bcm_enet_refill_rx(dev)) {
+ if (bcm_enet_refill_rx(dev, false)) {
dev_err(kdev, "cannot allocate rx skb queue\n");
ret = -ENOMEM;
goto out;
@@ -2305,18 +2310,7 @@ static int bcm_enetsw_open(struct net_device *dev)
return 0;
out:
- for (i = 0; i < priv->rx_ring_size; i++) {
- struct bcm_enet_desc *desc;
-
- if (!priv->rx_skb[i])
- continue;
-
- desc = &priv->rx_desc_cpu[i];
- dma_unmap_single(kdev, desc->address, priv->rx_skb_size,
- DMA_FROM_DEVICE);
- kfree_skb(priv->rx_skb[i]);
- }
- kfree(priv->rx_skb);
+ bcm_enet_free_rx_buf_ring(kdev, priv);
out_free_tx_skb:
kfree(priv->tx_skb);
@@ -2345,7 +2339,6 @@ static int bcm_enetsw_stop(struct net_device *dev)
{
struct bcm_enet_priv *priv;
struct device *kdev;
- int i;
priv = netdev_priv(dev);
kdev = &priv->pdev->dev;
@@ -2367,21 +2360,10 @@ static int bcm_enetsw_stop(struct net_device *dev)
/* force reclaim of all tx buffers */
bcm_enet_tx_reclaim(dev, 1);
- /* free the rx skb ring */
- for (i = 0; i < priv->rx_ring_size; i++) {
- struct bcm_enet_desc *desc;
-
- if (!priv->rx_skb[i])
- continue;
-
- desc = &priv->rx_desc_cpu[i];
- dma_unmap_single(kdev, desc->address, priv->rx_skb_size,
- DMA_FROM_DEVICE);
- kfree_skb(priv->rx_skb[i]);
- }
+ /* free the rx buffer ring */
+ bcm_enet_free_rx_buf_ring(kdev, priv);
/* free remaining allocated memory */
- kfree(priv->rx_skb);
kfree(priv->tx_skb);
dma_free_coherent(kdev, priv->rx_desc_alloc_size,
priv->rx_desc_cpu, priv->rx_desc_dma);
@@ -2678,6 +2660,7 @@ static int bcm_enetsw_probe(struct platform_device *pdev)
priv->rx_ring_size = BCMENET_DEF_RX_DESC;
priv->tx_ring_size = BCMENET_DEF_TX_DESC;
priv->dma_maxburst = BCMENETSW_DMA_MAXBURST;
+ priv->rx_buf_offset = NET_SKB_PAD + NET_IP_ALIGN;
pd = dev_get_platdata(&pdev->dev);
if (pd) {
diff --git a/drivers/net/ethernet/broadcom/bcm63xx_enet.h b/drivers/net/ethernet/broadcom/bcm63xx_enet.h
index 1d3c917eb830..78f1830fb3cb 100644
--- a/drivers/net/ethernet/broadcom/bcm63xx_enet.h
+++ b/drivers/net/ethernet/broadcom/bcm63xx_enet.h
@@ -230,11 +230,17 @@ struct bcm_enet_priv {
/* next dirty rx descriptor to refill */
int rx_dirty_desc;
- /* size of allocated rx skbs */
- unsigned int rx_skb_size;
+ /* size of allocated rx buffers */
+ unsigned int rx_buf_size;
- /* list of skb given to hw for rx */
- struct sk_buff **rx_skb;
+ /* allocated rx buffer offset */
+ unsigned int rx_buf_offset;
+
+ /* size of allocated rx frag */
+ unsigned int rx_frag_size;
+
+ /* list of buffer given to hw for rx */
+ void **rx_buf;
/* used when rx skb allocation failed, so we defer rx queue
* refill */
--
2.17.1
On Thu, 24 Dec 2020 22:24:15 +0800 Sieng Piaw Liew wrote:
> This patch series aim to improve the bcm63xx_enet driver by integrating the
> latest networking features, i.e. batched rx processing, BQL, build_skb, etc.
>
> The newer enetsw SoCs are found to be able to do unaligned rx DMA by adding
> NET_IP_ALIGN padding which, combined with these patches, improved packet
> processing performance by ~50% on BCM6328.
>
> Older non-enetsw SoCs still benefit mainly from rx batching. Performance
> improvement of ~30% is observed on BCM6333.
>
> The BCM63xx SoCs are designed for routers. As such, having BQL is beneficial
> as well as trivial to add.
Hopefully we can get some reviews now, but for inclusion in the tree
you'll need to repost once net-next opens (should happen in the next
few days):
http://vger.kernel.org/~davem/net-next.html
On 12/24/2020 6:24 AM, Sieng Piaw Liew wrote:
> Add Byte Queue Limits support to reduce/remove bufferbloat in
> bcm63xx_enet.
>
> Signed-off-by: Sieng Piaw Liew <[email protected]>
Acked-by: Florian Fainelli <[email protected]>
--
Florian
On 12/24/2020 6:24 AM, Sieng Piaw Liew wrote:
> Use existing rx processed count to track against budget, thereby making
> budget decrement operation redundant.
>
> rx_desc_count can be calculated outside the rx loop, making the loop a
> bit smaller.
>
> Signed-off-by: Sieng Piaw Liew <[email protected]>
Acked-by: Florian Fainelli <[email protected]>
--
Florian
On 12/24/2020 6:24 AM, Sieng Piaw Liew wrote:
> We can increase the efficiency of rx path by using buffers to receive
> packets then build SKBs around them just before passing into the network
> stack. In contrast, preallocating SKBs too early reduces CPU cache
> efficiency.
>
> Check if we're in NAPI context when refilling RX. Normally we're almost
> always running in NAPI context. Dispatch to napi_alloc_frag directly
> instead of relying on netdev_alloc_frag which does the same but
> with the overhead of local_bh_disable/enable.
>
> Tested on BCM6328 320 MHz and iperf3 -M 512 to measure packet/sec
> performance. Included netif_receive_skb_list and NET_IP_ALIGN
> optimizations.
>
> Before:
> [ ID] Interval Transfer Bandwidth Retr
> [ 4] 0.00-10.00 sec 49.9 MBytes 41.9 Mbits/sec 197 sender
> [ 4] 0.00-10.00 sec 49.3 MBytes 41.3 Mbits/sec receiver
>
> After:
> [ ID] Interval Transfer Bandwidth Retr
> [ 4] 0.00-30.00 sec 171 MBytes 47.8 Mbits/sec 272 sender
> [ 4] 0.00-30.00 sec 170 MBytes 47.6 Mbits/sec receiver
This looks good, however there are a few nits and suggestions below:
[snip]
> @@ -862,6 +868,24 @@ static void bcm_enet_adjust_link(struct net_device *dev)
> priv->pause_tx ? "tx" : "off");
> }
>
> +static void bcm_enet_free_rx_buf_ring(struct device *kdev, struct bcm_enet_priv *priv)
> +{
> + int i;
> +
> + for (i = 0; i < priv->rx_ring_size; i++) {
> + struct bcm_enet_desc *desc;
> +
> + if (!priv->rx_buf[i])
> + continue;
> +
> + desc = &priv->rx_desc_cpu[i];
> + dma_unmap_single(kdev, desc->address, priv->rx_buf_size,
> + DMA_FROM_DEVICE);
> + skb_free_frag(priv->rx_buf[i]);
> + }
> + kfree(priv->rx_buf);
> +}
This is a good helper to introduced, however I would introduce it as a
preliminary patch that way it becomes clear when you are doing the
sk_buff to buf substitution in the next patch.
[snip]
> @@ -1640,9 +1641,12 @@ static int bcm_enet_change_mtu(struct net_device *dev, int new_mtu)
> * align rx buffer size to dma burst len, account FCS since
> * it's appended
> */
> - priv->rx_skb_size = ALIGN(actual_mtu + ETH_FCS_LEN,
> + priv->rx_buf_size = ALIGN(actual_mtu + ETH_FCS_LEN,
> priv->dma_maxburst * 4);
>
> + priv->rx_frag_size = SKB_DATA_ALIGN(priv->rx_buf_offset + priv->rx_buf_size)
> + + SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
The alignment of the second line is a bit off and you should aim for the
+ operator to be on the preceding line, and have SKB_DATA_ALIGN() start
on the opening parenthesis of the preceding line.
--
Florian