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[PATCH] e100: Render e100 NAPI state machine
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Render e100 NAPI state machine to be similar to the non-NAPI one.

Signed-off-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Signed-off-by: Ganesh Venkatesan <ganesh.venkatesan@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>
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Malli Chilakala authored and Jeff Garzik committed May 13, 2005
1 parent 2acdb1e commit 1f53367
Showing 1 changed file with 71 additions and 15 deletions.
86 changes: 71 additions & 15 deletions drivers/net/e100.c
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Original file line number Diff line number Diff line change
Expand Up @@ -269,6 +269,12 @@ enum scb_status {
rus_mask = 0x3C,
};

enum ru_state {
RU_SUSPENDED = 0,
RU_RUNNING = 1,
RU_UNINITIALIZED = -1,
};

enum scb_stat_ack {
stat_ack_not_ours = 0x00,
stat_ack_sw_gen = 0x04,
Expand Down Expand Up @@ -510,7 +516,7 @@ struct nic {
struct rx *rx_to_use;
struct rx *rx_to_clean;
struct rfd blank_rfd;
int ru_running;
enum ru_state ru_running;

spinlock_t cb_lock ____cacheline_aligned;
spinlock_t cmd_lock;
Expand Down Expand Up @@ -1204,7 +1210,9 @@ static void e100_update_stats(struct nic *nic)
}
}

e100_exec_cmd(nic, cuc_dump_reset, 0);

if(e100_exec_cmd(nic, cuc_dump_reset, 0))
DPRINTK(TX_ERR, DEBUG, "exec cuc_dump_reset failed\n");
}

static void e100_adjust_adaptive_ifs(struct nic *nic, int speed, int duplex)
Expand Down Expand Up @@ -1298,7 +1306,8 @@ static int e100_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
/* SW workaround for ICH[x] 10Mbps/half duplex Tx hang.
Issue a NOP command followed by a 1us delay before
issuing the Tx command. */
e100_exec_cmd(nic, cuc_nop, 0);
if(e100_exec_cmd(nic, cuc_nop, 0))
DPRINTK(TX_ERR, DEBUG, "exec cuc_nop failed\n");
udelay(1);
}

Expand Down Expand Up @@ -1416,12 +1425,18 @@ static int e100_alloc_cbs(struct nic *nic)
return 0;
}

static inline void e100_start_receiver(struct nic *nic)
static inline void e100_start_receiver(struct nic *nic, struct rx *rx)
{
if(!nic->rxs) return;
if(RU_SUSPENDED != nic->ru_running) return;

/* handle init time starts */
if(!rx) rx = nic->rxs;

/* (Re)start RU if suspended or idle and RFA is non-NULL */
if(!nic->ru_running && nic->rx_to_clean->skb) {
e100_exec_cmd(nic, ruc_start, nic->rx_to_clean->dma_addr);
nic->ru_running = 1;
if(rx->skb) {
e100_exec_cmd(nic, ruc_start, rx->dma_addr);
nic->ru_running = RU_RUNNING;
}
}

Expand All @@ -1438,6 +1453,13 @@ static inline int e100_rx_alloc_skb(struct nic *nic, struct rx *rx)
rx->dma_addr = pci_map_single(nic->pdev, rx->skb->data,
RFD_BUF_LEN, PCI_DMA_BIDIRECTIONAL);

if(pci_dma_mapping_error(rx->dma_addr)) {
dev_kfree_skb_any(rx->skb);
rx->skb = 0;
rx->dma_addr = 0;
return -ENOMEM;
}

/* Link the RFD to end of RFA by linking previous RFD to
* this one, and clearing EL bit of previous. */
if(rx->prev->skb) {
Expand Down Expand Up @@ -1472,7 +1494,7 @@ static inline int e100_rx_indicate(struct nic *nic, struct rx *rx,

/* If data isn't ready, nothing to indicate */
if(unlikely(!(rfd_status & cb_complete)))
return -EAGAIN;
return -ENODATA;

/* Get actual data size */
actual_size = le16_to_cpu(rfd->actual_size) & 0x3FFF;
Expand All @@ -1483,6 +1505,10 @@ static inline int e100_rx_indicate(struct nic *nic, struct rx *rx,
pci_unmap_single(nic->pdev, rx->dma_addr,
RFD_BUF_LEN, PCI_DMA_FROMDEVICE);

/* this allows for a fast restart without re-enabling interrupts */
if(le16_to_cpu(rfd->command) & cb_el)
nic->ru_running = RU_SUSPENDED;

/* Pull off the RFD and put the actual data (minus eth hdr) */
skb_reserve(skb, sizeof(struct rfd));
skb_put(skb, actual_size);
Expand Down Expand Up @@ -1515,27 +1541,54 @@ static inline void e100_rx_clean(struct nic *nic, unsigned int *work_done,
unsigned int work_to_do)
{
struct rx *rx;
int restart_required = 0;
struct rx *rx_to_start = NULL;

/* are we already rnr? then pay attention!!! this ensures that
* the state machine progression never allows a start with a
* partially cleaned list, avoiding a race between hardware
* and rx_to_clean when in NAPI mode */
if(RU_SUSPENDED == nic->ru_running)
restart_required = 1;

/* Indicate newly arrived packets */
for(rx = nic->rx_to_clean; rx->skb; rx = nic->rx_to_clean = rx->next) {
if(e100_rx_indicate(nic, rx, work_done, work_to_do))
int err = e100_rx_indicate(nic, rx, work_done, work_to_do);
if(-EAGAIN == err) {
/* hit quota so have more work to do, restart once
* cleanup is complete */
restart_required = 0;
break;
} else if(-ENODATA == err)
break; /* No more to clean */
}

/* save our starting point as the place we'll restart the receiver */
if(restart_required)
rx_to_start = nic->rx_to_clean;

/* Alloc new skbs to refill list */
for(rx = nic->rx_to_use; !rx->skb; rx = nic->rx_to_use = rx->next) {
if(unlikely(e100_rx_alloc_skb(nic, rx)))
break; /* Better luck next time (see watchdog) */
}

e100_start_receiver(nic);
if(restart_required) {
// ack the rnr?
writeb(stat_ack_rnr, &nic->csr->scb.stat_ack);
e100_start_receiver(nic, rx_to_start);
if(work_done)
(*work_done)++;
}
}

static void e100_rx_clean_list(struct nic *nic)
{
struct rx *rx;
unsigned int i, count = nic->params.rfds.count;

nic->ru_running = RU_UNINITIALIZED;

if(nic->rxs) {
for(rx = nic->rxs, i = 0; i < count; rx++, i++) {
if(rx->skb) {
Expand All @@ -1549,7 +1602,6 @@ static void e100_rx_clean_list(struct nic *nic)
}

nic->rx_to_use = nic->rx_to_clean = NULL;
nic->ru_running = 0;
}

static int e100_rx_alloc_list(struct nic *nic)
Expand All @@ -1558,6 +1610,7 @@ static int e100_rx_alloc_list(struct nic *nic)
unsigned int i, count = nic->params.rfds.count;

nic->rx_to_use = nic->rx_to_clean = NULL;
nic->ru_running = RU_UNINITIALIZED;

if(!(nic->rxs = kmalloc(sizeof(struct rx) * count, GFP_ATOMIC)))
return -ENOMEM;
Expand All @@ -1573,6 +1626,7 @@ static int e100_rx_alloc_list(struct nic *nic)
}

nic->rx_to_use = nic->rx_to_clean = nic->rxs;
nic->ru_running = RU_SUSPENDED;

return 0;
}
Expand All @@ -1594,7 +1648,7 @@ static irqreturn_t e100_intr(int irq, void *dev_id, struct pt_regs *regs)

/* We hit Receive No Resource (RNR); restart RU after cleaning */
if(stat_ack & stat_ack_rnr)
nic->ru_running = 0;
nic->ru_running = RU_SUSPENDED;

e100_disable_irq(nic);
netif_rx_schedule(netdev);
Expand Down Expand Up @@ -1684,7 +1738,7 @@ static int e100_up(struct nic *nic)
if((err = e100_hw_init(nic)))
goto err_clean_cbs;
e100_set_multicast_list(nic->netdev);
e100_start_receiver(nic);
e100_start_receiver(nic, 0);
mod_timer(&nic->watchdog, jiffies);
if((err = request_irq(nic->pdev->irq, e100_intr, SA_SHIRQ,
nic->netdev->name, nic->netdev)))
Expand Down Expand Up @@ -1759,7 +1813,7 @@ static int e100_loopback_test(struct nic *nic, enum loopback loopback_mode)
mdio_write(nic->netdev, nic->mii.phy_id, MII_BMCR,
BMCR_LOOPBACK);

e100_start_receiver(nic);
e100_start_receiver(nic, 0);

if(!(skb = dev_alloc_skb(ETH_DATA_LEN))) {
err = -ENOMEM;
Expand Down Expand Up @@ -2233,6 +2287,7 @@ static int __devinit e100_probe(struct pci_dev *pdev,

e100_get_defaults(nic);

/* locks must be initialized before calling hw_reset */
spin_lock_init(&nic->cb_lock);
spin_lock_init(&nic->cmd_lock);

Expand Down Expand Up @@ -2348,7 +2403,8 @@ static int e100_resume(struct pci_dev *pdev)

pci_set_power_state(pdev, PCI_D0);
pci_restore_state(pdev);
e100_hw_init(nic);
if(e100_hw_init(nic))
DPRINTK(HW, ERR, "e100_hw_init failed\n");

netif_device_attach(netdev);
if(netif_running(netdev))
Expand Down

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