mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

via-velocity: remove the bounce buffers 

Executive summary: the bounce buffers are in my way

- they use something like a 64 * 1500 bytes area of PCI
  consistent area
- they are not resized when the MTU changes
- they are used
  - to hand-pad undersized packets. skb_pad anyone ?
  - to linearize fragmented skbs whose fragment count
    goes beyond the 7 fragments hardware limit in order
    to claim scatter-gather support

Actually the SG code is commented out and I wonder if it
could not be implemented (ab-)using the large send feature
of the chipset since the latter should support some
multi-descriptor packet transmitting.

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Fixed-by: Séguier Régis <rseguier@e-teleport.net>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This commit is contained in:
Francois Romieu 2008-07-11 00:03:44 +02:00 committed by Jeff Garzik
parent 79d16385c7
commit 580a690208
2 changed files with 18 additions and 59 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

72
drivers/net/via-velocity.c
View File

@ -1104,7 +1104,6 @@ static int velocity_init_rings(struct velocity_info *vptr)
{
int i;
unsigned int psize;
unsigned int tsize;
dma_addr_t pool_dma;
u8 *pool;
@ -1133,19 +1132,6 @@ static int velocity_init_rings(struct velocity_info *vptr)
vptr->rd_pool_dma = pool_dma;
tsize = vptr->options.numtx * PKT_BUF_SZ * vptr->num_txq;
vptr->tx_bufs = pci_alloc_consistent(vptr->pdev, tsize,
&vptr->tx_bufs_dma);
if (vptr->tx_bufs == NULL) {
printk(KERN_ERR "%s: DMA memory allocation failed.\n",
vptr->dev->name);
pci_free_consistent(vptr->pdev, psize, pool, pool_dma);
return -ENOMEM;
}
memset(vptr->tx_bufs, 0, vptr->options.numtx * PKT_BUF_SZ * vptr->num_txq);
i = vptr->options.numrx * sizeof(struct rx_desc);
pool += i;
pool_dma += i;
@ -1169,16 +1155,10 @@ static int velocity_init_rings(struct velocity_info *vptr)
static void velocity_free_rings(struct velocity_info *vptr)
{
int size;
size = vptr->options.numrx * sizeof(struct rx_desc) +
vptr->options.numtx * sizeof(struct tx_desc) * vptr->num_txq;
const int size = vptr->options.numrx * sizeof(struct rx_desc) +
vptr->options.numtx * sizeof(struct tx_desc) * vptr->num_txq;
pci_free_consistent(vptr->pdev, size, vptr->rd_ring, vptr->rd_pool_dma);
size = vptr->options.numtx * PKT_BUF_SZ * vptr->num_txq;
pci_free_consistent(vptr->pdev, size, vptr->tx_bufs, vptr->tx_bufs_dma);
}
static inline void velocity_give_many_rx_descs(struct velocity_info *vptr)
@ -1313,10 +1293,8 @@ static void velocity_free_rd_ring(struct velocity_info *vptr)
static int velocity_init_td_ring(struct velocity_info *vptr)
{
int i, j;
dma_addr_t curr;
struct tx_desc *td;
struct velocity_td_info *td_info;
unsigned int j;
/* Init the TD ring entries */
for (j = 0; j < vptr->num_txq; j++) {
@ -1331,14 +1309,6 @@ static int velocity_init_td_ring(struct velocity_info *vptr)
return -ENOMEM;
}
for (i = 0; i < vptr->options.numtx; i++, curr += sizeof(struct tx_desc)) {
td = &(vptr->td_rings[j][i]);
td_info = &(vptr->td_infos[j][i]);
td_info->buf = vptr->tx_bufs +
(j * vptr->options.numtx + i) * PKT_BUF_SZ;
td_info->buf_dma = vptr->tx_bufs_dma +
(j * vptr->options.numtx + i) * PKT_BUF_SZ;
}
vptr->td_tail[j] = vptr->td_curr[j] = vptr->td_used[j] = 0;
}
return 0;
@ -1867,7 +1837,7 @@ static void velocity_free_tx_buf(struct velocity_info *vptr, struct velocity_td_
/*
* Don't unmap the pre-allocated tx_bufs
*/
if (tdinfo->skb_dma && (tdinfo->skb_dma[0] != tdinfo->buf_dma)) {
if (tdinfo->skb_dma) {
for (i = 0; i < tdinfo->nskb_dma; i++) {
#ifdef VELOCITY_ZERO_COPY_SUPPORT
@ -2063,9 +2033,19 @@ static int velocity_xmit(struct sk_buff *skb, struct net_device *dev)
struct tx_desc *td_ptr;
struct velocity_td_info *tdinfo;
unsigned long flags;
int index;
int pktlen = skb->len;
__le16 len = cpu_to_le16(pktlen);
__le16 len;
int index;
if (skb->len < ETH_ZLEN) {
if (skb_padto(skb, ETH_ZLEN))
goto out;
pktlen = ETH_ZLEN;
}
len = cpu_to_le16(pktlen);
#ifdef VELOCITY_ZERO_COPY_SUPPORT
if (skb_shinfo(skb)->nr_frags > 6 && __skb_linearize(skb)) {
@ -2083,23 +2063,6 @@ static int velocity_xmit(struct sk_buff *skb, struct net_device *dev)
td_ptr->tdesc1.TCR = TCR0_TIC;
td_ptr->td_buf[0].size &= ~TD_QUEUE;
/*
* Pad short frames.
*/
if (pktlen < ETH_ZLEN) {
/* Cannot occur until ZC support */
pktlen = ETH_ZLEN;
len = cpu_to_le16(ETH_ZLEN);
skb_copy_from_linear_data(skb, tdinfo->buf, skb->len);
memset(tdinfo->buf + skb->len, 0, ETH_ZLEN - skb->len);
tdinfo->skb = skb;
tdinfo->skb_dma[0] = tdinfo->buf_dma;
td_ptr->tdesc0.len = len;
td_ptr->td_buf[0].pa_low = cpu_to_le32(tdinfo->skb_dma[0]);
td_ptr->td_buf[0].pa_high = 0;
td_ptr->td_buf[0].size = len; /* queue is 0 anyway */
tdinfo->nskb_dma = 1;
} else
#ifdef VELOCITY_ZERO_COPY_SUPPORT
if (skb_shinfo(skb)->nr_frags > 0) {
int nfrags = skb_shinfo(skb)->nr_frags;
@ -2191,7 +2154,8 @@ static int velocity_xmit(struct sk_buff *skb, struct net_device *dev)
}
dev->trans_start = jiffies;
spin_unlock_irqrestore(&vptr->lock, flags);
return 0;
out:
return NETDEV_TX_OK;
}
/**

5
drivers/net/via-velocity.h
View File

@ -236,10 +236,8 @@ struct velocity_rd_info {
struct velocity_td_info {
struct sk_buff *skb;
u8 *buf;
int nskb_dma;
dma_addr_t skb_dma[7];
dma_addr_t buf_dma;
};
enum velocity_owner {
@ -1506,9 +1504,6 @@ struct velocity_info {
dma_addr_t rd_pool_dma;
dma_addr_t td_pool_dma[TX_QUEUE_NO];
dma_addr_t tx_bufs_dma;
u8 *tx_bufs;
struct vlan_group *vlgrp;
u8 ip_addr[4];
enum chip_type chip_id;