1 files changed, 136 insertions, 68 deletions

diff --git a/drivers/net/e100.c b/drivers/net/e100.c
index b87402bc830..51cf577035b 100644
--- a/drivers/net/e100.c
+++ b/drivers/net/e100.c
@@ -106,6 +106,13 @@
  *	the RFD, the RFD must be dma_sync'ed to maintain a consistent
  *	view from software and hardware.
  *
+ *	In order to keep updates to the RFD link field from colliding with
+ *	hardware writes to mark packets complete, we use the feature that
+ *	hardware will not write to a size 0 descriptor and mark the previous
+ *	packet as end-of-list (EL).   After updating the link, we remove EL
+ *	and only then restore the size such that hardware may use the
+ *	previous-to-end RFD.
+ *
  *	Under typical operation, the  receive unit (RU) is start once,
  *	and the controller happily fills RFDs as frames arrive.  If
  *	replacement RFDs cannot be allocated, or the RU goes non-active,
@@ -281,6 +288,7 @@ struct csr {
 };
 
 enum scb_status {
+	rus_no_res       = 0x08,
 	rus_ready        = 0x10,
 	rus_mask         = 0x3C,
 };
@@ -393,12 +401,12 @@ enum cb_command {
 };
 
 struct rfd {
-	u16 status;
-	u16 command;
-	u32 link;
-	u32 rbd;
-	u16 actual_size;
-	u16 size;
+	__le16 status;
+	__le16 command;
+	__le32 link;
+	__le32 rbd;
+	__le16 actual_size;
+	__le16 size;
 };
 
 struct rx {
@@ -453,19 +461,19 @@ struct config {
 
 #define E100_MAX_MULTICAST_ADDRS	64
 struct multi {
-	u16 count;
+	__le16 count;
 	u8 addr[E100_MAX_MULTICAST_ADDRS * ETH_ALEN + 2/*pad*/];
 };
 
 /* Important: keep total struct u32-aligned */
 #define UCODE_SIZE			134
 struct cb {
-	u16 status;
-	u16 command;
-	u32 link;
+	__le16 status;
+	__le16 command;
+	__le32 link;
 	union {
 		u8 iaaddr[ETH_ALEN];
-		u32 ucode[UCODE_SIZE];
+		__le32 ucode[UCODE_SIZE];
 		struct config config;
 		struct multi multi;
 		struct {
@@ -474,12 +482,12 @@ struct cb {
 			u8 threshold;
 			u8 tbd_count;
 			struct {
-				u32 buf_addr;
-				u16 size;
+				__le32 buf_addr;
+				__le16 size;
 				u16 eol;
 			} tbd;
 		} tcb;
-		u32 dump_buffer_addr;
+		__le32 dump_buffer_addr;
 	} u;
 	struct cb *next, *prev;
 	dma_addr_t dma_addr;
@@ -491,15 +499,15 @@ enum loopback {
 };
 
 struct stats {
-	u32 tx_good_frames, tx_max_collisions, tx_late_collisions,
+	__le32 tx_good_frames, tx_max_collisions, tx_late_collisions,
 		tx_underruns, tx_lost_crs, tx_deferred, tx_single_collisions,
 		tx_multiple_collisions, tx_total_collisions;
-	u32 rx_good_frames, rx_crc_errors, rx_alignment_errors,
+	__le32 rx_good_frames, rx_crc_errors, rx_alignment_errors,
 		rx_resource_errors, rx_overrun_errors, rx_cdt_errors,
 		rx_short_frame_errors;
-	u32 fc_xmt_pause, fc_rcv_pause, fc_rcv_unsupported;
-	u16 xmt_tco_frames, rcv_tco_frames;
-	u32 complete;
+	__le32 fc_xmt_pause, fc_rcv_pause, fc_rcv_unsupported;
+	__le16 xmt_tco_frames, rcv_tco_frames;
+	__le32 complete;
 };
 
 struct mem {
@@ -544,7 +552,7 @@ struct nic {
 	struct cb *cb_to_use;
 	struct cb *cb_to_send;
 	struct cb *cb_to_clean;
-	u16 tx_command;
+	__le16 tx_command;
 	/* End: frequently used values: keep adjacent for cache effect */
 
 	enum {
@@ -585,7 +593,7 @@ struct nic {
 
 	u16 leds;
 	u16 eeprom_wc;
-	u16 eeprom[256];
+	__le16 eeprom[256];
 	spinlock_t mdio_lock;
 };
 
@@ -663,7 +671,7 @@ static int e100_self_test(struct nic *nic)
 	return 0;
 }
 
-static void e100_eeprom_write(struct nic *nic, u16 addr_len, u16 addr, u16 data)
+static void e100_eeprom_write(struct nic *nic, u16 addr_len, u16 addr, __le16 data)
 {
 	u32 cmd_addr_data[3];
 	u8 ctrl;
@@ -672,7 +680,7 @@ static void e100_eeprom_write(struct nic *nic, u16 addr_len, u16 addr, u16 data)
 	/* Three cmds: write/erase enable, write data, write/erase disable */
 	cmd_addr_data[0] = op_ewen << (addr_len - 2);
 	cmd_addr_data[1] = (((op_write << addr_len) | addr) << 16) |
-		cpu_to_le16(data);
+		le16_to_cpu(data);
 	cmd_addr_data[2] = op_ewds << (addr_len - 2);
 
 	/* Bit-bang cmds to write word to eeprom */
@@ -701,7 +709,7 @@ static void e100_eeprom_write(struct nic *nic, u16 addr_len, u16 addr, u16 data)
 };
 
 /* General technique stolen from the eepro100 driver - very clever */
-static u16 e100_eeprom_read(struct nic *nic, u16 *addr_len, u16 addr)
+static __le16 e100_eeprom_read(struct nic *nic, u16 *addr_len, u16 addr)
 {
 	u32 cmd_addr_data;
 	u16 data = 0;
@@ -738,7 +746,7 @@ static u16 e100_eeprom_read(struct nic *nic, u16 *addr_len, u16 addr)
 	iowrite8(0, &nic->csr->eeprom_ctrl_lo);
 	e100_write_flush(nic); udelay(4);
 
-	return le16_to_cpu(data);
+	return cpu_to_le16(data);
 };
 
 /* Load entire EEPROM image into driver cache and validate checksum */
@@ -753,13 +761,12 @@ static int e100_eeprom_load(struct nic *nic)
 	for(addr = 0; addr < nic->eeprom_wc; addr++) {
 		nic->eeprom[addr] = e100_eeprom_read(nic, &addr_len, addr);
 		if(addr < nic->eeprom_wc - 1)
-			checksum += cpu_to_le16(nic->eeprom[addr]);
+			checksum += le16_to_cpu(nic->eeprom[addr]);
 	}
 
 	/* The checksum, stored in the last word, is calculated such that
 	 * the sum of words should be 0xBABA */
-	checksum = le16_to_cpu(0xBABA - checksum);
-	if(checksum != nic->eeprom[nic->eeprom_wc - 1]) {
+	if (cpu_to_le16(0xBABA - checksum) != nic->eeprom[nic->eeprom_wc - 1]) {
 		DPRINTK(PROBE, ERR, "EEPROM corrupted\n");
 		if (!eeprom_bad_csum_allow)
 			return -EAGAIN;
@@ -786,8 +793,8 @@ static int e100_eeprom_save(struct nic *nic, u16 start, u16 count)
 	/* The checksum, stored in the last word, is calculated such that
 	 * the sum of words should be 0xBABA */
 	for(addr = 0; addr < nic->eeprom_wc - 1; addr++)
-		checksum += cpu_to_le16(nic->eeprom[addr]);
-	nic->eeprom[nic->eeprom_wc - 1] = le16_to_cpu(0xBABA - checksum);
+		checksum += le16_to_cpu(nic->eeprom[addr]);
+	nic->eeprom[nic->eeprom_wc - 1] = cpu_to_le16(0xBABA - checksum);
 	e100_eeprom_write(nic, addr_len, nic->eeprom_wc - 1,
 		nic->eeprom[nic->eeprom_wc - 1]);
 
@@ -952,7 +959,7 @@ static void e100_get_defaults(struct nic *nic)
 		((nic->mac >= mac_82558_D101_A4) ? cb_cid : cb_i));
 
 	/* Template for a freshly allocated RFD */
-	nic->blank_rfd.command = cpu_to_le16(cb_el);
+	nic->blank_rfd.command = 0;
 	nic->blank_rfd.rbd = 0xFFFFFFFF;
 	nic->blank_rfd.size = cpu_to_le16(VLAN_ETH_FRAME_LEN);
 
@@ -1485,15 +1492,15 @@ static void e100_update_stats(struct nic *nic)
 	struct net_device *dev = nic->netdev;
 	struct net_device_stats *ns = &dev->stats;
 	struct stats *s = &nic->mem->stats;
-	u32 *complete = (nic->mac < mac_82558_D101_A4) ? &s->fc_xmt_pause :
-		(nic->mac < mac_82559_D101M) ? (u32 *)&s->xmt_tco_frames :
+	__le32 *complete = (nic->mac < mac_82558_D101_A4) ? &s->fc_xmt_pause :
+		(nic->mac < mac_82559_D101M) ? (__le32 *)&s->xmt_tco_frames :
 		&s->complete;
 
 	/* Device's stats reporting may take several microseconds to
 	 * complete, so where always waiting for results of the
 	 * previous command. */
 
-	if(*complete == le32_to_cpu(cuc_dump_reset_complete)) {
+	if(*complete == cpu_to_le32(cuc_dump_reset_complete)) {
 		*complete = 0;
 		nic->tx_frames = le32_to_cpu(s->tx_good_frames);
 		nic->tx_collisions = le32_to_cpu(s->tx_total_collisions);
@@ -1783,7 +1790,7 @@ static 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)) {
+	if (pci_dma_mapping_error(rx->dma_addr)) {
 		dev_kfree_skb_any(rx->skb);
 		rx->skb = NULL;
 		rx->dma_addr = 0;
@@ -1791,15 +1798,11 @@ static int e100_rx_alloc_skb(struct nic *nic, struct rx *rx)
 	}
 
 	/* Link the RFD to end of RFA by linking previous RFD to
-	 * this one, and clearing EL bit of previous.  */
-	if(rx->prev->skb) {
+	 * this one.  We are safe to touch the previous RFD because
+	 * it is protected by the before last buffer's el bit being set */
+	if (rx->prev->skb) {
 		struct rfd *prev_rfd = (struct rfd *)rx->prev->skb->data;
-		put_unaligned(cpu_to_le32(rx->dma_addr),
-			(u32 *)&prev_rfd->link);
-		wmb();
-		prev_rfd->command &= ~cpu_to_le16(cb_el);
-		pci_dma_sync_single_for_device(nic->pdev, rx->prev->dma_addr,
-			sizeof(struct rfd), PCI_DMA_TODEVICE);
+		put_unaligned(cpu_to_le32(rx->dma_addr), &prev_rfd->link);
 	}
 
 	return 0;
@@ -1824,8 +1827,19 @@ static int e100_rx_indicate(struct nic *nic, struct rx *rx,
 	DPRINTK(RX_STATUS, DEBUG, "status=0x%04X\n", rfd_status);
 
 	/* If data isn't ready, nothing to indicate */
-	if(unlikely(!(rfd_status & cb_complete)))
+	if (unlikely(!(rfd_status & cb_complete))) {
+		/* If the next buffer has the el bit, but we think the receiver
+		 * is still running, check to see if it really stopped while
+		 * we had interrupts off.
+		 * This allows for a fast restart without re-enabling
+		 * interrupts */
+		if ((le16_to_cpu(rfd->command) & cb_el) &&
+		    (RU_RUNNING == nic->ru_running))
+
+			if (readb(&nic->csr->scb.status) & rus_no_res)
+				nic->ru_running = RU_SUSPENDED;
 		return -ENODATA;
+	}
 
 	/* Get actual data size */
 	actual_size = le16_to_cpu(rfd->actual_size) & 0x3FFF;
@@ -1836,9 +1850,18 @@ static 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)
+	/* If this buffer has the el bit, but we think the receiver
+	 * is still running, check to see if it really stopped while
+	 * we had interrupts off.
+	 * This allows for a fast restart without re-enabling interrupts.
+	 * This can happen when the RU sees the size change but also sees
+	 * the el bit set. */
+	if ((le16_to_cpu(rfd->command) & cb_el) &&
+	    (RU_RUNNING == nic->ru_running)) {
+
+	    if (readb(&nic->csr->scb.status) & rus_no_res)
 		nic->ru_running = RU_SUSPENDED;
+	}
 
 	/* Pull off the RFD and put the actual data (minus eth hdr) */
 	skb_reserve(skb, sizeof(struct rfd));
@@ -1870,31 +1893,30 @@ static 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;
+	int restart_required = 0, err = 0;
+	struct rx *old_before_last_rx, *new_before_last_rx;
+	struct rfd *old_before_last_rfd, *new_before_last_rfd;
 
 	/* Indicate newly arrived packets */
 	for(rx = nic->rx_to_clean; rx->skb; rx = nic->rx_to_clean = rx->next) {
-		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;
+		err = e100_rx_indicate(nic, rx, work_done, work_to_do);
+		/* Hit quota or no more to clean */
+		if (-EAGAIN == err || -ENODATA == err)
 			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;
+
+	/* On EAGAIN, hit quota so have more work to do, restart once
+	 * cleanup is complete.
+	 * Else, 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 (-EAGAIN != err && RU_SUSPENDED == nic->ru_running)
+		restart_required = 1;
+
+	old_before_last_rx = nic->rx_to_use->prev->prev;
+	old_before_last_rfd = (struct rfd *)old_before_last_rx->skb->data;
 
 	/* Alloc new skbs to refill list */
 	for(rx = nic->rx_to_use; !rx->skb; rx = nic->rx_to_use = rx->next) {
@@ -1902,10 +1924,42 @@ static void e100_rx_clean(struct nic *nic, unsigned int *work_done,
 			break; /* Better luck next time (see watchdog) */
 	}
 
+	new_before_last_rx = nic->rx_to_use->prev->prev;
+	if (new_before_last_rx != old_before_last_rx) {
+		/* Set the el-bit on the buffer that is before the last buffer.
+		 * This lets us update the next pointer on the last buffer
+		 * without worrying about hardware touching it.
+		 * We set the size to 0 to prevent hardware from touching this
+		 * buffer.
+		 * When the hardware hits the before last buffer with el-bit
+		 * and size of 0, it will RNR interrupt, the RUS will go into
+		 * the No Resources state.  It will not complete nor write to
+		 * this buffer. */
+		new_before_last_rfd =
+			(struct rfd *)new_before_last_rx->skb->data;
+		new_before_last_rfd->size = 0;
+		new_before_last_rfd->command |= cpu_to_le16(cb_el);
+		pci_dma_sync_single_for_device(nic->pdev,
+			new_before_last_rx->dma_addr, sizeof(struct rfd),
+			PCI_DMA_TODEVICE);
+
+		/* Now that we have a new stopping point, we can clear the old
+		 * stopping point.  We must sync twice to get the proper
+		 * ordering on the hardware side of things. */
+		old_before_last_rfd->command &= ~cpu_to_le16(cb_el);
+		pci_dma_sync_single_for_device(nic->pdev,
+			old_before_last_rx->dma_addr, sizeof(struct rfd),
+			PCI_DMA_TODEVICE);
+		old_before_last_rfd->size = cpu_to_le16(VLAN_ETH_FRAME_LEN);
+		pci_dma_sync_single_for_device(nic->pdev,
+			old_before_last_rx->dma_addr, sizeof(struct rfd),
+			PCI_DMA_TODEVICE);
+	}
+
 	if(restart_required) {
 		// ack the rnr?
 		writeb(stat_ack_rnr, &nic->csr->scb.stat_ack);
-		e100_start_receiver(nic, rx_to_start);
+		e100_start_receiver(nic, nic->rx_to_clean);
 		if(work_done)
 			(*work_done)++;
 	}
@@ -1937,6 +1991,7 @@ static int e100_rx_alloc_list(struct nic *nic)
 {
 	struct rx *rx;
 	unsigned int i, count = nic->params.rfds.count;
+	struct rfd *before_last;
 
 	nic->rx_to_use = nic->rx_to_clean = NULL;
 	nic->ru_running = RU_UNINITIALIZED;
@@ -1952,6 +2007,19 @@ static int e100_rx_alloc_list(struct nic *nic)
 			return -ENOMEM;
 		}
 	}
+	/* Set the el-bit on the buffer that is before the last buffer.
+	 * This lets us update the next pointer on the last buffer without
+	 * worrying about hardware touching it.
+	 * We set the size to 0 to prevent hardware from touching this buffer.
+	 * When the hardware hits the before last buffer with el-bit and size
+	 * of 0, it will RNR interrupt, the RU will go into the No Resources
+	 * state.  It will not complete nor write to this buffer. */
+	rx = nic->rxs->prev->prev;
+	before_last = (struct rfd *)rx->skb->data;
+	before_last->command |= cpu_to_le16(cb_el);
+	before_last->size = 0;
+	pci_dma_sync_single_for_device(nic->pdev, rx->dma_addr,
+		sizeof(struct rfd), PCI_DMA_TODEVICE);
 
 	nic->rx_to_use = nic->rx_to_clean = nic->rxs;
 	nic->ru_running = RU_SUSPENDED;
@@ -2369,7 +2437,7 @@ static const char e100_gstrings_test[][ETH_GSTRING_LEN] = {
 	"Mac loopback     (offline)",
 	"Phy loopback     (offline)",
 };
-#define E100_TEST_LEN	sizeof(e100_gstrings_test) / ETH_GSTRING_LEN
+#define E100_TEST_LEN	ARRAY_SIZE(e100_gstrings_test)
 
 static void e100_diag_test(struct net_device *netdev,
 	struct ethtool_test *test, u64 *data)
@@ -2431,7 +2499,7 @@ static const char e100_gstrings_stats[][ETH_GSTRING_LEN] = {
 	"rx_flow_control_unsupported", "tx_tco_packets", "rx_tco_packets",
 };
 #define E100_NET_STATS_LEN	21
-#define E100_STATS_LEN	sizeof(e100_gstrings_stats) / ETH_GSTRING_LEN
+#define E100_STATS_LEN	ARRAY_SIZE(e100_gstrings_stats)
 
 static int e100_get_sset_count(struct net_device *netdev, int sset)
 {