From b37cccf031bdcaba2f461cdb5a2b93ebbd0af03c Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Sat, 5 Jul 2014 15:14:40 +0100 Subject: [PATCH] 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: Robert Coerver Tested-by: Robert Coerver Signed-off-by: Maciej W. Rozycki Signed-off-by: David S. Miller --- drivers/net/fddi/defxx.c | 84 +++++++++++++++++++++++++++------------- 1 file changed, 58 insertions(+), 26 deletions(-) diff --git a/drivers/net/fddi/defxx.c b/drivers/net/fddi/defxx.c index 4c5a2fe67dfb..ed23288d1c55 100644 --- a/drivers/net/fddi/defxx.c +++ b/drivers/net/fddi/defxx.c @@ -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); + 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_map_single(bp->bus_dev, newskb->data, - PI_RCV_DATA_K_SIZE_MAX, - DMA_FROM_DEVICE); + (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 -- 2.20.1