Merge branch 'Fixes-for-SONIC-ethernet-driver'

Finn Thain says:

====================
Fixes for SONIC ethernet driver

Various SONIC driver problems have become apparent over the years,
including tx watchdog timeouts, lost packets and duplicated packets.

The problems are mostly caused by bugs in buffer handling, locking and
(re-)initialization code.

This patch series resolves these problems.

This series has been tested on National Semiconductor hardware (macsonic),
qemu-system-m68k (macsonic) and qemu-system-mips64el (jazzsonic).

The emulated dp8393x device used in QEMU also has bugs.
I have fixed the bugs that I know of in a series of patches at,
https://github.com/fthain/qemu/commits/sonic

Changed since v1:
 - Minor revisions as described in commit logs.
 - Deferred net-next patches.
Changed since v2:
 - Minor revisions as described in commit logs.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/natsemi/sonic.c

@@ -64,6 +64,8 @@ static int sonic_open(struct net_device *dev)
 
 	netif_dbg(lp, ifup, dev, "%s: initializing sonic driver\n", __func__);
 
+	spin_lock_init(&lp->lock);
+
 	for (i = 0; i < SONIC_NUM_RRS; i++) {
 		struct sk_buff *skb = netdev_alloc_skb(dev, SONIC_RBSIZE + 2);
 		if (skb == NULL) {
@@ -114,6 +116,24 @@ static int sonic_open(struct net_device *dev)
 	return 0;
 }
 
+/* Wait for the SONIC to become idle. */
+static void sonic_quiesce(struct net_device *dev, u16 mask)
+{
+	struct sonic_local * __maybe_unused lp = netdev_priv(dev);
+	int i;
+	u16 bits;
+
+	for (i = 0; i < 1000; ++i) {
+		bits = SONIC_READ(SONIC_CMD) & mask;
+		if (!bits)
+			return;
+		if (irqs_disabled() || in_interrupt())
+			udelay(20);
+		else
+			usleep_range(100, 200);
+	}
+	WARN_ONCE(1, "command deadline expired! 0x%04x\n", bits);
+}
 
 /*
  * Close the SONIC device
@@ -130,6 +150,9 @@ static int sonic_close(struct net_device *dev)
 	/*
 	 * stop the SONIC, disable interrupts
 	 */
+	SONIC_WRITE(SONIC_CMD, SONIC_CR_RXDIS);
+	sonic_quiesce(dev, SONIC_CR_ALL);
+
 	SONIC_WRITE(SONIC_IMR, 0);
 	SONIC_WRITE(SONIC_ISR, 0x7fff);
 	SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);
@@ -169,6 +192,9 @@ static void sonic_tx_timeout(struct net_device *dev)
 	 * put the Sonic into software-reset mode and
 	 * disable all interrupts before releasing DMA buffers
 	 */
+	SONIC_WRITE(SONIC_CMD, SONIC_CR_RXDIS);
+	sonic_quiesce(dev, SONIC_CR_ALL);
+
 	SONIC_WRITE(SONIC_IMR, 0);
 	SONIC_WRITE(SONIC_ISR, 0x7fff);
 	SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);
@@ -206,8 +232,6 @@ static void sonic_tx_timeout(struct net_device *dev)
  *   wake the tx queue
  * Concurrently with all of this, the SONIC is potentially writing to
  * the status flags of the TDs.
- * Until some mutual exclusion is added, this code will not work with SMP. However,
- * MIPS Jazz machines and m68k Macs were all uni-processor machines.
  */
 
 static int sonic_send_packet(struct sk_buff *skb, struct net_device *dev)
@@ -215,7 +239,8 @@ static int sonic_send_packet(struct sk_buff *skb, struct net_device *dev)
 	struct sonic_local *lp = netdev_priv(dev);
 	dma_addr_t laddr;
 	int length;
-	int entry = lp->next_tx;
+	int entry;
+	unsigned long flags;
 
 	netif_dbg(lp, tx_queued, dev, "%s: skb=%p\n", __func__, skb);
 
@@ -237,6 +262,10 @@ static int sonic_send_packet(struct sk_buff *skb, struct net_device *dev)
 		return NETDEV_TX_OK;
 	}
 
+	spin_lock_irqsave(&lp->lock, flags);
+
+	entry = lp->next_tx;
+
 	sonic_tda_put(dev, entry, SONIC_TD_STATUS, 0);       /* clear status */
 	sonic_tda_put(dev, entry, SONIC_TD_FRAG_COUNT, 1);   /* single fragment */
 	sonic_tda_put(dev, entry, SONIC_TD_PKTSIZE, length); /* length of packet */
@@ -246,10 +275,6 @@ static int sonic_send_packet(struct sk_buff *skb, struct net_device *dev)
 	sonic_tda_put(dev, entry, SONIC_TD_LINK,
 		sonic_tda_get(dev, entry, SONIC_TD_LINK) | SONIC_EOL);
 
-	/*
-	 * Must set tx_skb[entry] only after clearing status, and
-	 * before clearing EOL and before stopping queue
-	 */
 	wmb();
 	lp->tx_len[entry] = length;
 	lp->tx_laddr[entry] = laddr;
@@ -272,6 +297,8 @@ static int sonic_send_packet(struct sk_buff *skb, struct net_device *dev)
 
 	SONIC_WRITE(SONIC_CMD, SONIC_CR_TXP);
 
+	spin_unlock_irqrestore(&lp->lock, flags);
+
 	return NETDEV_TX_OK;
 }
 
@@ -284,15 +311,28 @@ static irqreturn_t sonic_interrupt(int irq, void *dev_id)
 	struct net_device *dev = dev_id;
 	struct sonic_local *lp = netdev_priv(dev);
 	int status;
+	unsigned long flags;
+
+	/* The lock has two purposes. Firstly, it synchronizes sonic_interrupt()
+	 * with sonic_send_packet() so that the two functions can share state.
+	 * Secondly, it makes sonic_interrupt() re-entrant, as that is required
+	 * by macsonic which must use two IRQs with different priority levels.
+	 */
+	spin_lock_irqsave(&lp->lock, flags);
+
+	status = SONIC_READ(SONIC_ISR) & SONIC_IMR_DEFAULT;
+	if (!status) {
+		spin_unlock_irqrestore(&lp->lock, flags);
 
-	if (!(status = SONIC_READ(SONIC_ISR) & SONIC_IMR_DEFAULT))
 		return IRQ_NONE;
+	}
 
 	do {
+		SONIC_WRITE(SONIC_ISR, status); /* clear the interrupt(s) */
+
 		if (status & SONIC_INT_PKTRX) {
 			netif_dbg(lp, intr, dev, "%s: packet rx\n", __func__);
 			sonic_rx(dev);	/* got packet(s) */
-			SONIC_WRITE(SONIC_ISR, SONIC_INT_PKTRX); /* clear the interrupt */
 		}
 
 		if (status & SONIC_INT_TXDN) {
@@ -300,11 +340,12 @@ static irqreturn_t sonic_interrupt(int irq, void *dev_id)
 			int td_status;
 			int freed_some = 0;
 
-			/* At this point, cur_tx is the index of a TD that is one of:
-			 *   unallocated/freed                          (status set   & tx_skb[entry] clear)
-			 *   allocated and sent                         (status set   & tx_skb[entry] set  )
-			 *   allocated and not yet sent                 (status clear & tx_skb[entry] set  )
-			 *   still being allocated by sonic_send_packet (status clear & tx_skb[entry] clear)
+			/* The state of a Transmit Descriptor may be inferred
+			 * from { tx_skb[entry], td_status } as follows.
+			 * { clear, clear } => the TD has never been used
+			 * { set,   clear } => the TD was handed to SONIC
+			 * { set,   set   } => the TD was handed back
+			 * { clear, set   } => the TD is available for re-use
 			 */
 
 			netif_dbg(lp, intr, dev, "%s: tx done\n", __func__);
@@ -313,18 +354,19 @@ static irqreturn_t sonic_interrupt(int irq, void *dev_id)
 				if ((td_status = sonic_tda_get(dev, entry, SONIC_TD_STATUS)) == 0)
 					break;
 
-				if (td_status & 0x0001) {
+				if (td_status & SONIC_TCR_PTX) {
 					lp->stats.tx_packets++;
 					lp->stats.tx_bytes += sonic_tda_get(dev, entry, SONIC_TD_PKTSIZE);
 				} else {
-					lp->stats.tx_errors++;
-					if (td_status & 0x0642)
+					if (td_status & (SONIC_TCR_EXD |
+					    SONIC_TCR_EXC | SONIC_TCR_BCM))
 						lp->stats.tx_aborted_errors++;
-					if (td_status & 0x0180)
+					if (td_status &
+					    (SONIC_TCR_NCRS | SONIC_TCR_CRLS))
 						lp->stats.tx_carrier_errors++;
-					if (td_status & 0x0020)
+					if (td_status & SONIC_TCR_OWC)
 						lp->stats.tx_window_errors++;
-					if (td_status & 0x0004)
+					if (td_status & SONIC_TCR_FU)
 						lp->stats.tx_fifo_errors++;
 				}
 
@@ -346,7 +388,6 @@ static irqreturn_t sonic_interrupt(int irq, void *dev_id)
 			if (freed_some || lp->tx_skb[entry] == NULL)
 				netif_wake_queue(dev);  /* The ring is no longer full */
 			lp->cur_tx = entry;
-			SONIC_WRITE(SONIC_ISR, SONIC_INT_TXDN); /* clear the interrupt */
 		}
 
 		/*
@@ -355,42 +396,37 @@ static irqreturn_t sonic_interrupt(int irq, void *dev_id)
 		if (status & SONIC_INT_RFO) {
 			netif_dbg(lp, rx_err, dev, "%s: rx fifo overrun\n",
 				  __func__);
-			lp->stats.rx_fifo_errors++;
-			SONIC_WRITE(SONIC_ISR, SONIC_INT_RFO); /* clear the interrupt */
 		}
 		if (status & SONIC_INT_RDE) {
 			netif_dbg(lp, rx_err, dev, "%s: rx descriptors exhausted\n",
 				  __func__);
-			lp->stats.rx_dropped++;
-			SONIC_WRITE(SONIC_ISR, SONIC_INT_RDE); /* clear the interrupt */
 		}
 		if (status & SONIC_INT_RBAE) {
 			netif_dbg(lp, rx_err, dev, "%s: rx buffer area exceeded\n",
 				  __func__);
-			lp->stats.rx_dropped++;
-			SONIC_WRITE(SONIC_ISR, SONIC_INT_RBAE); /* clear the interrupt */
 		}
 
 		/* counter overruns; all counters are 16bit wide */
-		if (status & SONIC_INT_FAE) {
+		if (status & SONIC_INT_FAE)
 			lp->stats.rx_frame_errors += 65536;
-			SONIC_WRITE(SONIC_ISR, SONIC_INT_FAE); /* clear the interrupt */
-		}
-		if (status & SONIC_INT_CRC) {
+		if (status & SONIC_INT_CRC)
 			lp->stats.rx_crc_errors += 65536;
-			SONIC_WRITE(SONIC_ISR, SONIC_INT_CRC); /* clear the interrupt */
-		}
-		if (status & SONIC_INT_MP) {
+		if (status & SONIC_INT_MP)
 			lp->stats.rx_missed_errors += 65536;
-			SONIC_WRITE(SONIC_ISR, SONIC_INT_MP); /* clear the interrupt */
-		}
 
 		/* transmit error */
 		if (status & SONIC_INT_TXER) {
-			if (SONIC_READ(SONIC_TCR) & SONIC_TCR_FU)
-				netif_dbg(lp, tx_err, dev, "%s: tx fifo underrun\n",
-					  __func__);
-			SONIC_WRITE(SONIC_ISR, SONIC_INT_TXER); /* clear the interrupt */
+			u16 tcr = SONIC_READ(SONIC_TCR);
+
+			netif_dbg(lp, tx_err, dev, "%s: TXER intr, TCR %04x\n",
+				  __func__, tcr);
+
+			if (tcr & (SONIC_TCR_EXD | SONIC_TCR_EXC |
+				   SONIC_TCR_FU | SONIC_TCR_BCM)) {
+				/* Aborted transmission. Try again. */
+				netif_stop_queue(dev);
+				SONIC_WRITE(SONIC_CMD, SONIC_CR_TXP);
+			}
 		}
 
 		/* bus retry */
@@ -400,107 +436,164 @@ static irqreturn_t sonic_interrupt(int irq, void *dev_id)
 			/* ... to help debug DMA problems causing endless interrupts. */
 			/* Bounce the eth interface to turn on the interrupt again. */
 			SONIC_WRITE(SONIC_IMR, 0);
-			SONIC_WRITE(SONIC_ISR, SONIC_INT_BR); /* clear the interrupt */
 		}
 
-		/* load CAM done */
-		if (status & SONIC_INT_LCD)
-			SONIC_WRITE(SONIC_ISR, SONIC_INT_LCD); /* clear the interrupt */
-	} while((status = SONIC_READ(SONIC_ISR) & SONIC_IMR_DEFAULT));
+		status = SONIC_READ(SONIC_ISR) & SONIC_IMR_DEFAULT;
+	} while (status);
+
+	spin_unlock_irqrestore(&lp->lock, flags);
+
 	return IRQ_HANDLED;
 }
 
+/* Return the array index corresponding to a given Receive Buffer pointer. */
+static int index_from_addr(struct sonic_local *lp, dma_addr_t addr,
+			   unsigned int last)
+{
+	unsigned int i = last;
+
+	do {
+		i = (i + 1) & SONIC_RRS_MASK;
+		if (addr == lp->rx_laddr[i])
+			return i;
+	} while (i != last);
+
+	return -ENOENT;
+}
+
+/* Allocate and map a new skb to be used as a receive buffer. */
+static bool sonic_alloc_rb(struct net_device *dev, struct sonic_local *lp,
+			   struct sk_buff **new_skb, dma_addr_t *new_addr)
+{
+	*new_skb = netdev_alloc_skb(dev, SONIC_RBSIZE + 2);
+	if (!*new_skb)
+		return false;
+
+	if (SONIC_BUS_SCALE(lp->dma_bitmode) == 2)
+		skb_reserve(*new_skb, 2);
+
+	*new_addr = dma_map_single(lp->device, skb_put(*new_skb, SONIC_RBSIZE),
+				   SONIC_RBSIZE, DMA_FROM_DEVICE);
+	if (!*new_addr) {
+		dev_kfree_skb(*new_skb);
+		*new_skb = NULL;
+		return false;
+	}
+
+	return true;
+}
+
+/* Place a new receive resource in the Receive Resource Area and update RWP. */
+static void sonic_update_rra(struct net_device *dev, struct sonic_local *lp,
+			     dma_addr_t old_addr, dma_addr_t new_addr)
+{
+	unsigned int entry = sonic_rr_entry(dev, SONIC_READ(SONIC_RWP));
+	unsigned int end = sonic_rr_entry(dev, SONIC_READ(SONIC_RRP));
+	u32 buf;
+
+	/* The resources in the range [RRP, RWP) belong to the SONIC. This loop
+	 * scans the other resources in the RRA, those in the range [RWP, RRP).
+	 */
+	do {
+		buf = (sonic_rra_get(dev, entry, SONIC_RR_BUFADR_H) << 16) |
+		      sonic_rra_get(dev, entry, SONIC_RR_BUFADR_L);
+
+		if (buf == old_addr)
+			break;
+
+		entry = (entry + 1) & SONIC_RRS_MASK;
+	} while (entry != end);
+
+	WARN_ONCE(buf != old_addr, "failed to find resource!\n");
+
+	sonic_rra_put(dev, entry, SONIC_RR_BUFADR_H, new_addr >> 16);
+	sonic_rra_put(dev, entry, SONIC_RR_BUFADR_L, new_addr & 0xffff);
+
+	entry = (entry + 1) & SONIC_RRS_MASK;
+
+	SONIC_WRITE(SONIC_RWP, sonic_rr_addr(dev, entry));
+}
+
 /*
  * We have a good packet(s), pass it/them up the network stack.
  */
 static void sonic_rx(struct net_device *dev)
 {
 	struct sonic_local *lp = netdev_priv(dev);
-	int status;
 	int entry = lp->cur_rx;
+	int prev_entry = lp->eol_rx;
+	bool rbe = false;
 
 	while (sonic_rda_get(dev, entry, SONIC_RD_IN_USE) == 0) {
-		struct sk_buff *used_skb;
+		u16 status = sonic_rda_get(dev, entry, SONIC_RD_STATUS);
+
+		/* If the RD has LPKT set, the chip has finished with the RB */
+		if ((status & SONIC_RCR_PRX) && (status & SONIC_RCR_LPKT)) {
 			struct sk_buff *new_skb;
 			dma_addr_t new_laddr;
-		u16 bufadr_l;
-		u16 bufadr_h;
-		int pkt_len;
+			u32 addr = (sonic_rda_get(dev, entry,
+						  SONIC_RD_PKTPTR_H) << 16) |
+				   sonic_rda_get(dev, entry, SONIC_RD_PKTPTR_L);
+			int i = index_from_addr(lp, addr, entry);
 
-		status = sonic_rda_get(dev, entry, SONIC_RD_STATUS);
-		if (status & SONIC_RCR_PRX) {
-			/* Malloc up new buffer. */
-			new_skb = netdev_alloc_skb(dev, SONIC_RBSIZE + 2);
-			if (new_skb == NULL) {
-				lp->stats.rx_dropped++;
+			if (i < 0) {
+				WARN_ONCE(1, "failed to find buffer!\n");
 				break;
 			}
-			/* provide 16 byte IP header alignment unless DMA requires otherwise */
-			if(SONIC_BUS_SCALE(lp->dma_bitmode) == 2)
-				skb_reserve(new_skb, 2);
 
-			new_laddr = dma_map_single(lp->device, skb_put(new_skb, SONIC_RBSIZE),
-		                               SONIC_RBSIZE, DMA_FROM_DEVICE);
-			if (!new_laddr) {
-				dev_kfree_skb(new_skb);
-				printk(KERN_ERR "%s: Failed to map rx buffer, dropping packet.\n", dev->name);
-				lp->stats.rx_dropped++;
-				break;
-			}
+			if (sonic_alloc_rb(dev, lp, &new_skb, &new_laddr)) {
+				struct sk_buff *used_skb = lp->rx_skb[i];
+				int pkt_len;
 
-			/* now we have a new skb to replace it, pass the used one up the stack */
-			dma_unmap_single(lp->device, lp->rx_laddr[entry], SONIC_RBSIZE, DMA_FROM_DEVICE);
-			used_skb = lp->rx_skb[entry];
-			pkt_len = sonic_rda_get(dev, entry, SONIC_RD_PKTLEN);
+				/* Pass the used buffer up the stack */
+				dma_unmap_single(lp->device, addr, SONIC_RBSIZE,
+						 DMA_FROM_DEVICE);
+
+				pkt_len = sonic_rda_get(dev, entry,
+							SONIC_RD_PKTLEN);
 				skb_trim(used_skb, pkt_len);
-			used_skb->protocol = eth_type_trans(used_skb, dev);
+				used_skb->protocol = eth_type_trans(used_skb,
+								    dev);
 				netif_rx(used_skb);
 				lp->stats.rx_packets++;
 				lp->stats.rx_bytes += pkt_len;
 
-			/* and insert the new skb */
-			lp->rx_laddr[entry] = new_laddr;
-			lp->rx_skb[entry] = new_skb;
-
-			bufadr_l = (unsigned long)new_laddr & 0xffff;
-			bufadr_h = (unsigned long)new_laddr >> 16;
-			sonic_rra_put(dev, entry, SONIC_RR_BUFADR_L, bufadr_l);
-			sonic_rra_put(dev, entry, SONIC_RR_BUFADR_H, bufadr_h);
+				lp->rx_skb[i] = new_skb;
+				lp->rx_laddr[i] = new_laddr;
 			} else {
-			/* This should only happen, if we enable accepting broken packets. */
-			lp->stats.rx_errors++;
-			if (status & SONIC_RCR_FAER)
-				lp->stats.rx_frame_errors++;
-			if (status & SONIC_RCR_CRCR)
-				lp->stats.rx_crc_errors++;
-		}
-		if (status & SONIC_RCR_LPKT) {
-			/*
-			 * this was the last packet out of the current receive buffer
-			 * give the buffer back to the SONIC
+				/* Failed to obtain a new buffer so re-use it */
+				new_laddr = addr;
+				lp->stats.rx_dropped++;
+			}
+			/* If RBE is already asserted when RWP advances then
+			 * it's safe to clear RBE after processing this packet.
 			 */
-			lp->cur_rwp += SIZEOF_SONIC_RR * SONIC_BUS_SCALE(lp->dma_bitmode);
-			if (lp->cur_rwp >= lp->rra_end) lp->cur_rwp = lp->rra_laddr & 0xffff;
-			SONIC_WRITE(SONIC_RWP, lp->cur_rwp);
-			if (SONIC_READ(SONIC_ISR) & SONIC_INT_RBE) {
-				netif_dbg(lp, rx_err, dev, "%s: rx buffer exhausted\n",
-					  __func__);
-				SONIC_WRITE(SONIC_ISR, SONIC_INT_RBE); /* clear the flag */
+			rbe = rbe || SONIC_READ(SONIC_ISR) & SONIC_INT_RBE;
+			sonic_update_rra(dev, lp, addr, new_laddr);
 		}
-		} else
-			printk(KERN_ERR "%s: rx desc without RCR_LPKT. Shouldn't happen !?\n",
-			     dev->name);
 		/*
 		 * give back the descriptor
 		 */
-		sonic_rda_put(dev, entry, SONIC_RD_LINK,
-			sonic_rda_get(dev, entry, SONIC_RD_LINK) | SONIC_EOL);
+		sonic_rda_put(dev, entry, SONIC_RD_STATUS, 0);
 		sonic_rda_put(dev, entry, SONIC_RD_IN_USE, 1);
-		sonic_rda_put(dev, lp->eol_rx, SONIC_RD_LINK,
-			sonic_rda_get(dev, lp->eol_rx, SONIC_RD_LINK) & ~SONIC_EOL);
-		lp->eol_rx = entry;
-		lp->cur_rx = entry = (entry + 1) & SONIC_RDS_MASK;
+
+		prev_entry = entry;
+		entry = (entry + 1) & SONIC_RDS_MASK;
+	}
+
+	lp->cur_rx = entry;
+
+	if (prev_entry != lp->eol_rx) {
+		/* Advance the EOL flag to put descriptors back into service */
+		sonic_rda_put(dev, prev_entry, SONIC_RD_LINK, SONIC_EOL |
+			      sonic_rda_get(dev, prev_entry, SONIC_RD_LINK));
+		sonic_rda_put(dev, lp->eol_rx, SONIC_RD_LINK, ~SONIC_EOL &
+			      sonic_rda_get(dev, lp->eol_rx, SONIC_RD_LINK));
+		lp->eol_rx = prev_entry;
 	}
+
+	if (rbe)
+		SONIC_WRITE(SONIC_ISR, SONIC_INT_RBE);
 	/*
 	 * If any worth-while packets have been received, netif_rx()
 	 * has done a mark_bh(NET_BH) for us and will work on them
@@ -550,6 +643,8 @@ static void sonic_multicast_list(struct net_device *dev)
 		    (netdev_mc_count(dev) > 15)) {
 			rcr |= SONIC_RCR_AMC;
 		} else {
+			unsigned long flags;
+
 			netif_dbg(lp, ifup, dev, "%s: mc_count %d\n", __func__,
 				  netdev_mc_count(dev));
 			sonic_set_cam_enable(dev, 1);  /* always enable our own address */
@@ -563,9 +658,14 @@ static void sonic_multicast_list(struct net_device *dev)
 				i++;
 			}
 			SONIC_WRITE(SONIC_CDC, 16);
-			/* issue Load CAM command */
 			SONIC_WRITE(SONIC_CDP, lp->cda_laddr & 0xffff);
+
+			/* LCAM and TXP commands can't be used simultaneously */
+			spin_lock_irqsave(&lp->lock, flags);
+			sonic_quiesce(dev, SONIC_CR_TXP);
 			SONIC_WRITE(SONIC_CMD, SONIC_CR_LCAM);
+			sonic_quiesce(dev, SONIC_CR_LCAM);
+			spin_unlock_irqrestore(&lp->lock, flags);
 		}
 	}
 
@@ -580,7 +680,6 @@ static void sonic_multicast_list(struct net_device *dev)
  */
 static int sonic_init(struct net_device *dev)
 {
-	unsigned int cmd;
 	struct sonic_local *lp = netdev_priv(dev);
 	int i;
 
@@ -592,12 +691,16 @@ static int sonic_init(struct net_device *dev)
 	SONIC_WRITE(SONIC_ISR, 0x7fff);
 	SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);
 
+	/* While in reset mode, clear CAM Enable register */
+	SONIC_WRITE(SONIC_CE, 0);
+
 	/*
 	 * clear software reset flag, disable receiver, clear and
 	 * enable interrupts, then completely initialize the SONIC
 	 */
 	SONIC_WRITE(SONIC_CMD, 0);
-	SONIC_WRITE(SONIC_CMD, SONIC_CR_RXDIS);
+	SONIC_WRITE(SONIC_CMD, SONIC_CR_RXDIS | SONIC_CR_STP);
+	sonic_quiesce(dev, SONIC_CR_ALL);
 
 	/*
 	 * initialize the receive resource area
@@ -615,15 +718,10 @@ static int sonic_init(struct net_device *dev)
 	}
 
 	/* initialize all RRA registers */
-	lp->rra_end = (lp->rra_laddr + SONIC_NUM_RRS * SIZEOF_SONIC_RR *
-					SONIC_BUS_SCALE(lp->dma_bitmode)) & 0xffff;
-	lp->cur_rwp = (lp->rra_laddr + (SONIC_NUM_RRS - 1) * SIZEOF_SONIC_RR *
-					SONIC_BUS_SCALE(lp->dma_bitmode)) & 0xffff;
-
-	SONIC_WRITE(SONIC_RSA, lp->rra_laddr & 0xffff);
-	SONIC_WRITE(SONIC_REA, lp->rra_end);
-	SONIC_WRITE(SONIC_RRP, lp->rra_laddr & 0xffff);
-	SONIC_WRITE(SONIC_RWP, lp->cur_rwp);
+	SONIC_WRITE(SONIC_RSA, sonic_rr_addr(dev, 0));
+	SONIC_WRITE(SONIC_REA, sonic_rr_addr(dev, SONIC_NUM_RRS));
+	SONIC_WRITE(SONIC_RRP, sonic_rr_addr(dev, 0));
+	SONIC_WRITE(SONIC_RWP, sonic_rr_addr(dev, SONIC_NUM_RRS - 1));
 	SONIC_WRITE(SONIC_URRA, lp->rra_laddr >> 16);
 	SONIC_WRITE(SONIC_EOBC, (SONIC_RBSIZE >> 1) - (lp->dma_bitmode ? 2 : 1));
 
@@ -631,14 +729,7 @@ static int sonic_init(struct net_device *dev)
 	netif_dbg(lp, ifup, dev, "%s: issuing RRRA command\n", __func__);
 
 	SONIC_WRITE(SONIC_CMD, SONIC_CR_RRRA);
-	i = 0;
-	while (i++ < 100) {
-		if (SONIC_READ(SONIC_CMD) & SONIC_CR_RRRA)
-			break;
-	}
-
-	netif_dbg(lp, ifup, dev, "%s: status=%x, i=%d\n", __func__,
-		  SONIC_READ(SONIC_CMD), i);
+	sonic_quiesce(dev, SONIC_CR_RRRA);
 
 	/*
 	 * Initialize the receive descriptors so that they
@@ -713,28 +804,17 @@ static int sonic_init(struct net_device *dev)
 	 * load the CAM
 	 */
 	SONIC_WRITE(SONIC_CMD, SONIC_CR_LCAM);
-
-	i = 0;
-	while (i++ < 100) {
-		if (SONIC_READ(SONIC_ISR) & SONIC_INT_LCD)
-			break;
-	}
-	netif_dbg(lp, ifup, dev, "%s: CMD=%x, ISR=%x, i=%d\n", __func__,
-		  SONIC_READ(SONIC_CMD), SONIC_READ(SONIC_ISR), i);
+	sonic_quiesce(dev, SONIC_CR_LCAM);
 
 	/*
 	 * enable receiver, disable loopback
 	 * and enable all interrupts
 	 */
-	SONIC_WRITE(SONIC_CMD, SONIC_CR_RXEN | SONIC_CR_STP);
 	SONIC_WRITE(SONIC_RCR, SONIC_RCR_DEFAULT);
 	SONIC_WRITE(SONIC_TCR, SONIC_TCR_DEFAULT);
 	SONIC_WRITE(SONIC_ISR, 0x7fff);
 	SONIC_WRITE(SONIC_IMR, SONIC_IMR_DEFAULT);
-
-	cmd = SONIC_READ(SONIC_CMD);
-	if ((cmd & SONIC_CR_RXEN) == 0 || (cmd & SONIC_CR_STP) == 0)
-		printk(KERN_ERR "sonic_init: failed, status=%x\n", cmd);
+	SONIC_WRITE(SONIC_CMD, SONIC_CR_RXEN);
 
 	netif_dbg(lp, ifup, dev, "%s: new status=%x\n", __func__,
 		  SONIC_READ(SONIC_CMD));

drivers/net/ethernet/natsemi/sonic.h

@@ -110,6 +110,9 @@
 #define SONIC_CR_TXP            0x0002
 #define SONIC_CR_HTX            0x0001
 
+#define SONIC_CR_ALL (SONIC_CR_LCAM | SONIC_CR_RRRA | \
+		      SONIC_CR_RXEN | SONIC_CR_TXP)
+
 /*
  * SONIC data configuration bits
  */
@@ -175,6 +178,7 @@
 #define SONIC_TCR_NCRS          0x0100
 #define SONIC_TCR_CRLS          0x0080
 #define SONIC_TCR_EXC           0x0040
+#define SONIC_TCR_OWC           0x0020
 #define SONIC_TCR_PMB           0x0008
 #define SONIC_TCR_FU            0x0004
 #define SONIC_TCR_BCM           0x0002
@@ -274,8 +278,9 @@
 #define SONIC_NUM_RDS   SONIC_NUM_RRS /* number of receive descriptors */
 #define SONIC_NUM_TDS   16            /* number of transmit descriptors */
 
-#define SONIC_RDS_MASK  (SONIC_NUM_RDS-1)
-#define SONIC_TDS_MASK  (SONIC_NUM_TDS-1)
+#define SONIC_RRS_MASK  (SONIC_NUM_RRS - 1)
+#define SONIC_RDS_MASK  (SONIC_NUM_RDS - 1)
+#define SONIC_TDS_MASK  (SONIC_NUM_TDS - 1)
 
 #define SONIC_RBSIZE	1520          /* size of one resource buffer */
 
@@ -312,8 +317,6 @@ struct sonic_local {
 	u32 rda_laddr;              /* logical DMA address of RDA */
 	dma_addr_t rx_laddr[SONIC_NUM_RRS]; /* logical DMA addresses of rx skbuffs */
 	dma_addr_t tx_laddr[SONIC_NUM_TDS]; /* logical DMA addresses of tx skbuffs */
-	unsigned int rra_end;
-	unsigned int cur_rwp;
 	unsigned int cur_rx;
 	unsigned int cur_tx;           /* first unacked transmit packet */
 	unsigned int eol_rx;
@@ -322,6 +325,7 @@ struct sonic_local {
 	int msg_enable;
 	struct device *device;         /* generic device */
 	struct net_device_stats stats;
+	spinlock_t lock;
 };
 
 #define TX_TIMEOUT (3 * HZ)
@@ -344,30 +348,30 @@ static void sonic_msg_init(struct net_device *dev);
    as far as we can tell. */
 /* OpenBSD calls this "SWO".  I'd like to think that sonic_buf_put()
    is a much better name. */
-static inline void sonic_buf_put(void* base, int bitmode,
+static inline void sonic_buf_put(u16 *base, int bitmode,
 				 int offset, __u16 val)
 {
 	if (bitmode)
 #ifdef __BIG_ENDIAN
-		((__u16 *) base + (offset*2))[1] = val;
+		__raw_writew(val, base + (offset * 2) + 1);
 #else
-		((__u16 *) base + (offset*2))[0] = val;
+		__raw_writew(val, base + (offset * 2) + 0);
 #endif
 	else
-	 	((__u16 *) base)[offset] = val;
+		__raw_writew(val, base + (offset * 1) + 0);
 }
 
-static inline __u16 sonic_buf_get(void* base, int bitmode,
+static inline __u16 sonic_buf_get(u16 *base, int bitmode,
 				  int offset)
 {
 	if (bitmode)
 #ifdef __BIG_ENDIAN
-		return ((volatile __u16 *) base + (offset*2))[1];
+		return __raw_readw(base + (offset * 2) + 1);
 #else
-		return ((volatile __u16 *) base + (offset*2))[0];
+		return __raw_readw(base + (offset * 2) + 0);
 #endif
 	else
-		return ((volatile __u16 *) base)[offset];
+		return __raw_readw(base + (offset * 1) + 0);
 }
 
 /* Inlines that you should actually use for reading/writing DMA buffers */
@@ -447,6 +451,22 @@ static inline __u16 sonic_rra_get(struct net_device* dev, int entry,
 			     (entry * SIZEOF_SONIC_RR) + offset);
 }
 
+static inline u16 sonic_rr_addr(struct net_device *dev, int entry)
+{
+	struct sonic_local *lp = netdev_priv(dev);
+
+	return lp->rra_laddr +
+	       entry * SIZEOF_SONIC_RR * SONIC_BUS_SCALE(lp->dma_bitmode);
+}
+
+static inline u16 sonic_rr_entry(struct net_device *dev, u16 addr)
+{
+	struct sonic_local *lp = netdev_priv(dev);
+
+	return (addr - (u16)lp->rra_laddr) / (SIZEOF_SONIC_RR *
+					      SONIC_BUS_SCALE(lp->dma_bitmode));
+}
+
 static const char version[] =
     "sonic.c:v0.92 20.9.98 tsbogend@alpha.franken.de\n";