[PATCH] e100: Render e100 NAPI state machine
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>
diff --git a/drivers/net/e100.c b/drivers/net/e100.c
index 0f2837e..2c8c14e 100644
--- a/drivers/net/e100.c
+++ b/drivers/net/e100.c
@@ -269,6 +269,12 @@
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,
@@ -510,7 +516,7 @@
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;
@@ -1204,7 +1210,9 @@
}
}
- 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)
@@ -1298,7 +1306,8 @@
/* 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);
}
@@ -1416,12 +1425,18 @@
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;
}
}
@@ -1438,6 +1453,13 @@
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) {
@@ -1472,7 +1494,7 @@
/* 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;
@@ -1483,6 +1505,10 @@
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);
@@ -1515,20 +1541,45 @@
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)
@@ -1536,6 +1587,8 @@
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) {
@@ -1549,7 +1602,6 @@
}
nic->rx_to_use = nic->rx_to_clean = NULL;
- nic->ru_running = 0;
}
static int e100_rx_alloc_list(struct nic *nic)
@@ -1558,6 +1610,7 @@
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;
@@ -1573,6 +1626,7 @@
}
nic->rx_to_use = nic->rx_to_clean = nic->rxs;
+ nic->ru_running = RU_SUSPENDED;
return 0;
}
@@ -1594,7 +1648,7 @@
/* 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);
@@ -1684,7 +1738,7 @@
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)))
@@ -1759,7 +1813,7 @@
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;
@@ -2233,6 +2287,7 @@
e100_get_defaults(nic);
+ /* locks must be initialized before calling hw_reset */
spin_lock_init(&nic->cb_lock);
spin_lock_init(&nic->cmd_lock);
@@ -2348,7 +2403,8 @@
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))