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net: ll_temac: fix checksum offload logic
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The current checksum offload code does not work and this corrects
that functionality. It also updates the interrupt coallescing
initialization so than there are fewer interrupts and performance
is increased.

Signed-off-by: Brian Hill <brian.hill@xilinx.com>
Signed-off-by: John Linn <john.linn@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Brian Hill authored and David S. Miller committed May 27, 2010
1 parent 755fae0 commit 23ecc4b
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Showing 2 changed files with 63 additions and 24 deletions.
5 changes: 5 additions & 0 deletions drivers/net/ll_temac.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -295,6 +295,10 @@ This option defaults to enabled (set) */

#define MULTICAST_CAM_TABLE_NUM 4

/* TEMAC Synthesis features */
#define TEMAC_FEATURE_RX_CSUM (1 << 0)
#define TEMAC_FEATURE_TX_CSUM (1 << 1)

/* TX/RX CURDESC_PTR points to first descriptor */
/* TX/RX TAILDESC_PTR points to last descriptor in linked list */

Expand Down Expand Up @@ -353,6 +357,7 @@ struct temac_local {
struct mutex indirect_mutex;
u32 options; /* Current options word */
int last_link;
unsigned int temac_features;

/* Buffer descriptors */
struct cdmac_bd *tx_bd_v;
Expand Down
82 changes: 58 additions & 24 deletions drivers/net/ll_temac_main.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -245,7 +245,7 @@ static int temac_dma_bd_init(struct net_device *ndev)
CHNL_CTRL_IRQ_COAL_EN);
/* 0x10220483 */
/* 0x00100483 */
lp->dma_out(lp, RX_CHNL_CTRL, 0xff010000 |
lp->dma_out(lp, RX_CHNL_CTRL, 0xff070000 |
CHNL_CTRL_IRQ_EN |
CHNL_CTRL_IRQ_DLY_EN |
CHNL_CTRL_IRQ_COAL_EN |
Expand Down Expand Up @@ -574,6 +574,10 @@ static void temac_start_xmit_done(struct net_device *ndev)
if (cur_p->app4)
dev_kfree_skb_irq((struct sk_buff *)cur_p->app4);
cur_p->app0 = 0;
cur_p->app1 = 0;
cur_p->app2 = 0;
cur_p->app3 = 0;
cur_p->app4 = 0;

ndev->stats.tx_packets++;
ndev->stats.tx_bytes += cur_p->len;
Expand All @@ -589,6 +593,29 @@ static void temac_start_xmit_done(struct net_device *ndev)
netif_wake_queue(ndev);
}

static inline int temac_check_tx_bd_space(struct temac_local *lp, int num_frag)
{
struct cdmac_bd *cur_p;
int tail;

tail = lp->tx_bd_tail;
cur_p = &lp->tx_bd_v[tail];

do {
if (cur_p->app0)
return NETDEV_TX_BUSY;

tail++;
if (tail >= TX_BD_NUM)
tail = 0;

cur_p = &lp->tx_bd_v[tail];
num_frag--;
} while (num_frag >= 0);

return 0;
}

static int temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
struct temac_local *lp = netdev_priv(ndev);
Expand All @@ -603,7 +630,7 @@ static int temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
start_p = lp->tx_bd_p + sizeof(*lp->tx_bd_v) * lp->tx_bd_tail;
cur_p = &lp->tx_bd_v[lp->tx_bd_tail];

if (cur_p->app0 & STS_CTRL_APP0_CMPLT) {
if (temac_check_tx_bd_space(lp, num_frag)) {
if (!netif_queue_stopped(ndev)) {
netif_stop_queue(ndev);
return NETDEV_TX_BUSY;
Expand All @@ -613,29 +640,14 @@ static int temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)

cur_p->app0 = 0;
if (skb->ip_summed == CHECKSUM_PARTIAL) {
const struct iphdr *ip = ip_hdr(skb);
int length = 0, start = 0, insert = 0;

switch (ip->protocol) {
case IPPROTO_TCP:
start = sizeof(struct iphdr) + ETH_HLEN;
insert = sizeof(struct iphdr) + ETH_HLEN + 16;
length = ip->tot_len - sizeof(struct iphdr);
break;
case IPPROTO_UDP:
start = sizeof(struct iphdr) + ETH_HLEN;
insert = sizeof(struct iphdr) + ETH_HLEN + 6;
length = ip->tot_len - sizeof(struct iphdr);
break;
default:
break;
}
cur_p->app1 = ((start << 16) | insert);
cur_p->app2 = csum_tcpudp_magic(ip->saddr, ip->daddr,
length, ip->protocol, 0);
skb->data[insert] = 0;
skb->data[insert + 1] = 0;
unsigned int csum_start_off = skb_transport_offset(skb);
unsigned int csum_index_off = csum_start_off + skb->csum_offset;

cur_p->app0 |= 1; /* TX Checksum Enabled */
cur_p->app1 = (csum_start_off << 16) | csum_index_off;
cur_p->app2 = 0; /* initial checksum seed */
}

cur_p->app0 |= STS_CTRL_APP0_SOP;
cur_p->len = skb_headlen(skb);
cur_p->phys = dma_map_single(ndev->dev.parent, skb->data, skb->len,
Expand Down Expand Up @@ -699,6 +711,15 @@ static void ll_temac_recv(struct net_device *ndev)
skb->protocol = eth_type_trans(skb, ndev);
skb->ip_summed = CHECKSUM_NONE;

/* if we're doing rx csum offload, set it up */
if (((lp->temac_features & TEMAC_FEATURE_RX_CSUM) != 0) &&
(skb->protocol == __constant_htons(ETH_P_IP)) &&
(skb->len > 64)) {

skb->csum = cur_p->app3 & 0xFFFF;
skb->ip_summed = CHECKSUM_COMPLETE;
}

netif_rx(skb);

ndev->stats.rx_packets++;
Expand Down Expand Up @@ -883,6 +904,7 @@ temac_of_probe(struct of_device *op, const struct of_device_id *match)
struct temac_local *lp;
struct net_device *ndev;
const void *addr;
__be32 *p;
int size, rc = 0;

/* Init network device structure */
Expand Down Expand Up @@ -926,6 +948,18 @@ temac_of_probe(struct of_device *op, const struct of_device_id *match)
goto nodev;
}

/* Setup checksum offload, but default to off if not specified */
lp->temac_features = 0;
p = (__be32 *)of_get_property(op->dev.of_node, "xlnx,txcsum", NULL);
if (p && be32_to_cpu(*p)) {
lp->temac_features |= TEMAC_FEATURE_TX_CSUM;
/* Can checksum TCP/UDP over IPv4. */
ndev->features |= NETIF_F_IP_CSUM;
}
p = (__be32 *)of_get_property(op->dev.of_node, "xlnx,rxcsum", NULL);
if (p && be32_to_cpu(*p))
lp->temac_features |= TEMAC_FEATURE_RX_CSUM;

/* Find the DMA node, map the DMA registers, and decode the DMA IRQs */
np = of_parse_phandle(op->node, "llink-connected", 0);
if (!np) {
Expand Down

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