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Commit b37cccf0 authored by Maciej W. Rozycki's avatar Maciej W. Rozycki Committed by David S. Miller
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defxx: Handle DMA mapping errors 



This adds error handling for DMA mapping requests; I think there isn't
much else to say about it.

A good side-effect is the mapping in the transmit path is now made with
the board lock released.  Also if DMA mapping fails for a newly
allocated receive buffer, then data from the old buffer will be copied
out (as is presently done for small frames only whose size does not
exceed SKBUFF_RX_COPYBREAK) and the original buffer returned, with its
mapping unchanged, to the DMA descriptor ring.

Reported-by: default avatarRobert Coerver <Robert.Coerver@ll.mit.edu>
Tested-by: default avatarRobert Coerver <Robert.Coerver@ll.mit.edu>
Signed-off-by: default avatarMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a630be70

drivers/net/fddi/defxx.c

+58 −26
Original line number Diff line number Diff line
@@ -2923,21 +2923,35 @@ static int dfx_rcv_init(DFX_board_t *bp, int get_buffers) 
	for (i = 0; i < (int)(bp->rcv_bufs_to_post); i++)

		for (j = 0; (i + j) < (int)PI_RCV_DATA_K_NUM_ENTRIES; j += bp->rcv_bufs_to_post)

		{

			struct sk_buff *newskb = __netdev_alloc_skb(bp->dev, NEW_SKB_SIZE, GFP_NOIO);

			struct sk_buff *newskb;

			dma_addr_t dma_addr;



			newskb = __netdev_alloc_skb(bp->dev, NEW_SKB_SIZE,

						    GFP_NOIO);

			if (!newskb)

				return -ENOMEM;

			bp->descr_block_virt->rcv_data[i+j].long_0 = (u32) (PI_RCV_DESCR_M_SOP |

				((PI_RCV_DATA_K_SIZE_MAX / PI_ALIGN_K_RCV_DATA_BUFF) << PI_RCV_DESCR_V_SEG_LEN));

			/*

			 * align to 128 bytes for compatibility with

			 * the old EISA boards.

			 */



			my_skb_align(newskb, 128);

			bp->descr_block_virt->rcv_data[i + j].long_1 =

				(u32)dma_map_single(bp->bus_dev, newskb->data,

			dma_addr = dma_map_single(bp->bus_dev,

						  newskb->data,

						  PI_RCV_DATA_K_SIZE_MAX,

						  DMA_FROM_DEVICE);

			if (dma_mapping_error(bp->bus_dev, dma_addr)) {

				dev_kfree_skb(newskb);

				return -ENOMEM;

			}

			bp->descr_block_virt->rcv_data[i + j].long_0 =

				(u32)(PI_RCV_DESCR_M_SOP |

				      ((PI_RCV_DATA_K_SIZE_MAX /

					PI_ALIGN_K_RCV_DATA_BUFF) <<

				       PI_RCV_DESCR_V_SEG_LEN));

			bp->descr_block_virt->rcv_data[i + j].long_1 =

				(u32)dma_addr;



			/*

			 * p_rcv_buff_va is only used inside the

			 * kernel so we put the skb pointer here.
@@ -3004,7 +3018,7 @@ static void dfx_rcv_queue_process( 
	PI_TYPE_2_CONSUMER	*p_type_2_cons;		/* ptr to rcv/xmt consumer block register */

	char				*p_buff;			/* ptr to start of packet receive buffer (FMC descriptor) */

	u32					descr, pkt_len;		/* FMC descriptor field and packet length */

	struct sk_buff		*skb;				/* pointer to a sk_buff to hold incoming packet data */

	struct sk_buff		*skb = NULL;			/* pointer to a sk_buff to hold incoming packet data */



	/* Service all consumed LLC receive frames */
@@ -3042,15 +3056,30 @@ static void dfx_rcv_queue_process( 
				bp->rcv_length_errors++;

			else{

#ifdef DYNAMIC_BUFFERS

				struct sk_buff *newskb = NULL;



				if (pkt_len > SKBUFF_RX_COPYBREAK) {

					struct sk_buff *newskb;

					dma_addr_t new_dma_addr;



					newskb = netdev_alloc_skb(bp->dev,

								  NEW_SKB_SIZE);

					if (newskb){

						my_skb_align(newskb, 128);

						new_dma_addr = dma_map_single(

								bp->bus_dev,

								newskb->data,

								PI_RCV_DATA_K_SIZE_MAX,

								DMA_FROM_DEVICE);

						if (dma_mapping_error(

								bp->bus_dev,

								new_dma_addr)) {

							dev_kfree_skb(newskb);

							newskb = NULL;

						}

					}

					if (newskb) {

						rx_in_place = 1;



						my_skb_align(newskb, 128);

						skb = (struct sk_buff *)bp->p_rcv_buff_va[entry];

						dma_unmap_single(bp->bus_dev,

							bp->descr_block_virt->rcv_data[entry].long_1,
@@ -3058,14 +3087,10 @@ static void dfx_rcv_queue_process( 
							DMA_FROM_DEVICE);

						skb_reserve(skb, RCV_BUFF_K_PADDING);

						bp->p_rcv_buff_va[entry] = (char *)newskb;

						bp->descr_block_virt->rcv_data[entry].long_1 =

							(u32)dma_map_single(bp->bus_dev,

								newskb->data,

								PI_RCV_DATA_K_SIZE_MAX,

								DMA_FROM_DEVICE);

					} else

						skb = NULL;

				} else

						bp->descr_block_virt->rcv_data[entry].long_1 = (u32)new_dma_addr;

					}

				}

				if (!newskb)

#endif

					/* Alloc new buffer to pass up,

					 * add room for PRH. */
@@ -3185,6 +3210,7 @@ static netdev_tx_t dfx_xmt_queue_pkt(struct sk_buff *skb, 
	u8			prod;				/* local transmit producer index */

	PI_XMT_DESCR		*p_xmt_descr;		/* ptr to transmit descriptor block entry */

	XMT_DRIVER_DESCR	*p_xmt_drv_descr;	/* ptr to transmit driver descriptor */

	dma_addr_t		dma_addr;

	unsigned long		flags;



	netif_stop_queue(dev);
@@ -3232,6 +3258,20 @@ static netdev_tx_t dfx_xmt_queue_pkt(struct sk_buff *skb, 
			}

		}



	/* Write the three PRH bytes immediately before the FC byte */



	skb_push(skb, 3);

	skb->data[0] = DFX_PRH0_BYTE;	/* these byte values are defined */

	skb->data[1] = DFX_PRH1_BYTE;	/* in the Motorola FDDI MAC chip */

	skb->data[2] = DFX_PRH2_BYTE;	/* specification */



	dma_addr = dma_map_single(bp->bus_dev, skb->data, skb->len,

				  DMA_TO_DEVICE);

	if (dma_mapping_error(bp->bus_dev, dma_addr)) {

		skb_pull(skb, 3);

		return NETDEV_TX_BUSY;

	}



	spin_lock_irqsave(&bp->lock, flags);



	/* Get the current producer and the next free xmt data descriptor */
@@ -3252,13 +3292,6 @@ static netdev_tx_t dfx_xmt_queue_pkt(struct sk_buff *skb, 


	p_xmt_drv_descr = &(bp->xmt_drv_descr_blk[prod++]);	/* also bump producer index */



	/* Write the three PRH bytes immediately before the FC byte */



	skb_push(skb,3);

	skb->data[0] = DFX_PRH0_BYTE;	/* these byte values are defined */

	skb->data[1] = DFX_PRH1_BYTE;	/* in the Motorola FDDI MAC chip */

	skb->data[2] = DFX_PRH2_BYTE;	/* specification */



	/*

	 * Write the descriptor with buffer info and bump producer

	 *
@@ -3287,8 +3320,7 @@ static netdev_tx_t dfx_xmt_queue_pkt(struct sk_buff *skb, 
	 */



	p_xmt_descr->long_0	= (u32) (PI_XMT_DESCR_M_SOP | PI_XMT_DESCR_M_EOP | ((skb->len) << PI_XMT_DESCR_V_SEG_LEN));

	p_xmt_descr->long_1 = (u32)dma_map_single(bp->bus_dev, skb->data,

						  skb->len, DMA_TO_DEVICE);

	p_xmt_descr->long_1 = (u32)dma_addr;



	/*

	 * Verify that descriptor is actually available