Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 22087d65 authored by Christian Lamparter's avatar Christian Lamparter Committed by David S. Miller
Browse files

net: emac: remove IBM_EMAC_RX_SKB_HEADROOM 



The EMAC driver had a custom IBM_EMAC_RX_SKB_HEADROOM
Kconfig option that reserved additional skb headroom for RX.
This patch removes the option and migrates the code
to use napi_alloc_skb() and netdev_alloc_skb_ip_align()
in its place.

Signed-off-by: default avatarChristian Lamparter <chunkeey@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a6e11f6b

drivers/net/ethernet/ibm/emac/Kconfig

+0 −12
Original line number Diff line number Diff line
@@ -28,18 +28,6 @@ config IBM_EMAC_RX_COPY_THRESHOLD 
	depends on IBM_EMAC

	default "256"



config IBM_EMAC_RX_SKB_HEADROOM

	int "Additional RX skb headroom (bytes)"

	depends on IBM_EMAC

	default "0"

	help

	  Additional receive skb headroom. Note, that driver

	  will always reserve at least 2 bytes to make IP header

	  aligned, so usually there is no need to add any additional

	  headroom.



	  If unsure, set to 0.



config IBM_EMAC_DEBUG

	bool "Debugging"

	depends on IBM_EMAC

drivers/net/ethernet/ibm/emac/core.c

+44 −20
Original line number Diff line number Diff line
@@ -1071,7 +1071,9 @@ static int emac_resize_rx_ring(struct emac_instance *dev, int new_mtu) 


	/* Second pass, allocate new skbs */

	for (i = 0; i < NUM_RX_BUFF; ++i) {

		struct sk_buff *skb = alloc_skb(rx_skb_size, GFP_ATOMIC);

		struct sk_buff *skb;



		skb = netdev_alloc_skb_ip_align(dev->ndev, rx_skb_size);

		if (!skb) {

			ret = -ENOMEM;

			goto oom;
@@ -1080,10 +1082,10 @@ static int emac_resize_rx_ring(struct emac_instance *dev, int new_mtu) 
		BUG_ON(!dev->rx_skb[i]);

		dev_kfree_skb(dev->rx_skb[i]);



		skb_reserve(skb, EMAC_RX_SKB_HEADROOM + 2);

		dev->rx_desc[i].data_ptr =

		    dma_map_single(&dev->ofdev->dev, skb->data - 2, rx_sync_size,

				   DMA_FROM_DEVICE) + 2;

		    dma_map_single(&dev->ofdev->dev, skb->data - NET_IP_ALIGN,

				   rx_sync_size, DMA_FROM_DEVICE)

				   + NET_IP_ALIGN;

		dev->rx_skb[i] = skb;

	}

 skip:
@@ -1174,20 +1176,18 @@ static void emac_clean_rx_ring(struct emac_instance *dev) 
	}

}



static inline int emac_alloc_rx_skb(struct emac_instance *dev, int slot,

				    gfp_t flags)

static int

__emac_prepare_rx_skb(struct sk_buff *skb, struct emac_instance *dev, int slot)

{

	struct sk_buff *skb = alloc_skb(dev->rx_skb_size, flags);

	if (unlikely(!skb))

		return -ENOMEM;



	dev->rx_skb[slot] = skb;

	dev->rx_desc[slot].data_len = 0;



	skb_reserve(skb, EMAC_RX_SKB_HEADROOM + 2);

	dev->rx_desc[slot].data_ptr =

	    dma_map_single(&dev->ofdev->dev, skb->data - 2, dev->rx_sync_size,

			   DMA_FROM_DEVICE) + 2;

	    dma_map_single(&dev->ofdev->dev, skb->data - NET_IP_ALIGN,

			   dev->rx_sync_size, DMA_FROM_DEVICE) + NET_IP_ALIGN;

	wmb();

	dev->rx_desc[slot].ctrl = MAL_RX_CTRL_EMPTY |

	    (slot == (NUM_RX_BUFF - 1) ? MAL_RX_CTRL_WRAP : 0);
@@ -1195,6 +1195,27 @@ static inline int emac_alloc_rx_skb(struct emac_instance *dev, int slot, 
	return 0;

}



static int

emac_alloc_rx_skb(struct emac_instance *dev, int slot)

{

	struct sk_buff *skb;



	skb = __netdev_alloc_skb_ip_align(dev->ndev, dev->rx_skb_size,

					  GFP_KERNEL);



	return __emac_prepare_rx_skb(skb, dev, slot);

}



static int

emac_alloc_rx_skb_napi(struct emac_instance *dev, int slot)

{

	struct sk_buff *skb;



	skb = napi_alloc_skb(&dev->mal->napi, dev->rx_skb_size);



	return __emac_prepare_rx_skb(skb, dev, slot);

}



static void emac_print_link_status(struct emac_instance *dev)

{

	if (netif_carrier_ok(dev->ndev))
@@ -1225,7 +1246,7 @@ static int emac_open(struct net_device *ndev) 


	/* Allocate RX ring */

	for (i = 0; i < NUM_RX_BUFF; ++i)

		if (emac_alloc_rx_skb(dev, i, GFP_KERNEL)) {

		if (emac_alloc_rx_skb(dev, i)) {

			printk(KERN_ERR "%s: failed to allocate RX ring\n",

			       ndev->name);

			goto oom;
@@ -1660,8 +1681,9 @@ static inline void emac_recycle_rx_skb(struct emac_instance *dev, int slot, 
	DBG2(dev, "recycle %d %d" NL, slot, len);



	if (len)

		dma_map_single(&dev->ofdev->dev, skb->data - 2,

			       EMAC_DMA_ALIGN(len + 2), DMA_FROM_DEVICE);

		dma_map_single(&dev->ofdev->dev, skb->data - NET_IP_ALIGN,

			       SKB_DATA_ALIGN(len + NET_IP_ALIGN),

			       DMA_FROM_DEVICE);



	dev->rx_desc[slot].data_len = 0;

	wmb();
@@ -1713,7 +1735,7 @@ static inline int emac_rx_sg_append(struct emac_instance *dev, int slot) 
		int len = dev->rx_desc[slot].data_len;

		int tot_len = dev->rx_sg_skb->len + len;



		if (unlikely(tot_len + 2 > dev->rx_skb_size)) {

		if (unlikely(tot_len + NET_IP_ALIGN > dev->rx_skb_size)) {

			++dev->estats.rx_dropped_mtu;

			dev_kfree_skb(dev->rx_sg_skb);

			dev->rx_sg_skb = NULL;
@@ -1769,16 +1791,18 @@ static int emac_poll_rx(void *param, int budget) 
		}



		if (len && len < EMAC_RX_COPY_THRESH) {

			struct sk_buff *copy_skb =

			    alloc_skb(len + EMAC_RX_SKB_HEADROOM + 2, GFP_ATOMIC);

			struct sk_buff *copy_skb;



			copy_skb = napi_alloc_skb(&dev->mal->napi, len);

			if (unlikely(!copy_skb))

				goto oom;



			skb_reserve(copy_skb, EMAC_RX_SKB_HEADROOM + 2);

			memcpy(copy_skb->data - 2, skb->data - 2, len + 2);

			memcpy(copy_skb->data - NET_IP_ALIGN,

			       skb->data - NET_IP_ALIGN,

			       len + NET_IP_ALIGN);

			emac_recycle_rx_skb(dev, slot, len);

			skb = copy_skb;

		} else if (unlikely(emac_alloc_rx_skb(dev, slot, GFP_ATOMIC)))

		} else if (unlikely(emac_alloc_rx_skb_napi(dev, slot)))

			goto oom;



		skb_put(skb, len);
@@ -1799,7 +1823,7 @@ static int emac_poll_rx(void *param, int budget) 
	sg:

		if (ctrl & MAL_RX_CTRL_FIRST) {

			BUG_ON(dev->rx_sg_skb);

			if (unlikely(emac_alloc_rx_skb(dev, slot, GFP_ATOMIC))) {

			if (unlikely(emac_alloc_rx_skb_napi(dev, slot))) {

				DBG(dev, "rx OOM %d" NL, slot);

				++dev->estats.rx_dropped_oom;

				emac_recycle_rx_skb(dev, slot, 0);

drivers/net/ethernet/ibm/emac/core.h

+3 −7
Original line number Diff line number Diff line
@@ -68,22 +68,18 @@ static inline int emac_rx_size(int mtu) 
		return mal_rx_size(ETH_DATA_LEN + EMAC_MTU_OVERHEAD);

}



#define EMAC_DMA_ALIGN(x)		ALIGN((x), dma_get_cache_alignment())



#define EMAC_RX_SKB_HEADROOM		\

	EMAC_DMA_ALIGN(CONFIG_IBM_EMAC_RX_SKB_HEADROOM)



/* Size of RX skb for the given MTU */

static inline int emac_rx_skb_size(int mtu)

{

	int size = max(mtu + EMAC_MTU_OVERHEAD, emac_rx_size(mtu));

	return EMAC_DMA_ALIGN(size + 2) + EMAC_RX_SKB_HEADROOM;



	return SKB_DATA_ALIGN(size + NET_IP_ALIGN) + NET_SKB_PAD;

}



/* RX DMA sync size */

static inline int emac_rx_sync_size(int mtu)

{

	return EMAC_DMA_ALIGN(emac_rx_size(mtu) + 2);

	return SKB_DATA_ALIGN(emac_rx_size(mtu) + NET_IP_ALIGN);

}



/* Driver statistcs is split into two parts to make it more cache friendly: