mirror of
				git://git.openwrt.org/openwrt/openwrt.git
				synced 2025-10-31 14:04:26 -04:00 
			
		
		
		
	
		
			
				
	
	
		
			67 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			67 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| From: Felix Fietkau <nbd@nbd.name>
 | |
| Date: Sun, 12 Apr 2015 10:13:28 +0200
 | |
| Subject: [PATCH] bgmac: set received skb headroom to NET_SKB_PAD
 | |
| 
 | |
| A packet buffer offset of 30 bytes is inefficient, because the first 2
 | |
| bytes end up in a different cacheline.
 | |
| 
 | |
| Signed-off-by: Felix Fietkau <nbd@nbd.name>
 | |
| ---
 | |
| 
 | |
| --- a/drivers/net/ethernet/broadcom/bgmac.c
 | |
| +++ b/drivers/net/ethernet/broadcom/bgmac.c
 | |
| @@ -346,13 +346,13 @@ static int bgmac_dma_rx_skb_for_slot(str
 | |
|  		return -ENOMEM;
 | |
|  
 | |
|  	/* Poison - if everything goes fine, hardware will overwrite it */
 | |
| -	rx = buf;
 | |
| +	rx = buf + BGMAC_RX_BUF_OFFSET;
 | |
|  	rx->len = cpu_to_le16(0xdead);
 | |
|  	rx->flags = cpu_to_le16(0xbeef);
 | |
|  
 | |
|  	/* Map skb for the DMA */
 | |
| -	dma_addr = dma_map_single(dma_dev, buf, BGMAC_RX_BUF_SIZE,
 | |
| -				  DMA_FROM_DEVICE);
 | |
| +	dma_addr = dma_map_single(dma_dev, buf + BGMAC_RX_BUF_OFFSET,
 | |
| +				  BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
 | |
|  	if (dma_mapping_error(dma_dev, dma_addr)) {
 | |
|  		bgmac_err(bgmac, "DMA mapping error\n");
 | |
|  		put_page(virt_to_head_page(buf));
 | |
| @@ -403,7 +403,7 @@ static int bgmac_dma_rx_read(struct bgma
 | |
|  	while (ring->start != ring->end) {
 | |
|  		struct device *dma_dev = bgmac->core->dma_dev;
 | |
|  		struct bgmac_slot_info *slot = &ring->slots[ring->start];
 | |
| -		struct bgmac_rx_header *rx = slot->buf;
 | |
| +		struct bgmac_rx_header *rx = slot->buf + BGMAC_RX_BUF_OFFSET;
 | |
|  		struct sk_buff *skb;
 | |
|  		void *buf = slot->buf;
 | |
|  		u16 len, flags;
 | |
| @@ -454,8 +454,10 @@ static int bgmac_dma_rx_read(struct bgma
 | |
|  					 BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
 | |
|  
 | |
|  			skb = build_skb(buf, BGMAC_RX_ALLOC_SIZE);
 | |
| -			skb_put(skb, BGMAC_RX_FRAME_OFFSET + len);
 | |
| -			skb_pull(skb, BGMAC_RX_FRAME_OFFSET);
 | |
| +			skb_put(skb, BGMAC_RX_FRAME_OFFSET +
 | |
| +				BGMAC_RX_BUF_OFFSET + len);
 | |
| +			skb_pull(skb, BGMAC_RX_FRAME_OFFSET +
 | |
| +				 BGMAC_RX_BUF_OFFSET);
 | |
|  
 | |
|  			skb_checksum_none_assert(skb);
 | |
|  			skb->protocol = eth_type_trans(skb, bgmac->net_dev);
 | |
| --- a/drivers/net/ethernet/broadcom/bgmac.h
 | |
| +++ b/drivers/net/ethernet/broadcom/bgmac.h
 | |
| @@ -360,9 +360,11 @@
 | |
|  
 | |
|  #define BGMAC_RX_HEADER_LEN			28		/* Last 24 bytes are unused. Well... */
 | |
|  #define BGMAC_RX_FRAME_OFFSET			30		/* There are 2 unused bytes between header and real data */
 | |
| +#define BGMAC_RX_BUF_OFFSET			(NET_SKB_PAD + NET_IP_ALIGN - \
 | |
| +						 BGMAC_RX_FRAME_OFFSET)
 | |
|  #define BGMAC_RX_MAX_FRAME_SIZE			1536		/* Copied from b44/tg3 */
 | |
|  #define BGMAC_RX_BUF_SIZE			(BGMAC_RX_FRAME_OFFSET + BGMAC_RX_MAX_FRAME_SIZE)
 | |
| -#define BGMAC_RX_ALLOC_SIZE			(SKB_DATA_ALIGN(BGMAC_RX_BUF_SIZE) + \
 | |
| +#define BGMAC_RX_ALLOC_SIZE			(SKB_DATA_ALIGN(BGMAC_RX_BUF_SIZE + BGMAC_RX_BUF_OFFSET) + \
 | |
|  						 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
 | |
|  
 | |
|  #define BGMAC_BFL_ENETROBO			0x0010		/* has ephy roboswitch spi */
 |