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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: Robert Coerver <Robert.Coerver@ll.mit.edu>
Tested-by: Robert Coerver <Robert.Coerver@ll.mit.edu>
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Maciej W. Rozycki 2014-07-05 15:14:40 +01:00 committed by David S. Miller
parent a630be7077
commit b37cccf031
1 changed files with 58 additions and 26 deletions
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84
drivers/net/fddi/defxx.c
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@ -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