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Message-ID: <Pine.LNX.4.64.0803120121580.7717@unm84.unminc.com>
Date: Wed, 12 Mar 2008 01:31:58 -0700
From: Dhananjay Phadke <dhananjay@...xen.com>
To: <netdev@...r.kernel.org>
CC: Jeff Garzik <jeff@...zik.org>
Subject: [PATCH 3/4] netxen: remove low level tx lock
o eliminate tx lock in netxen adapter struct, instead pound on netdev
tx lock appropriately.
o remove old "concurrent transmit" code that unnecessarily drops and
reacquires tx lock in hard_xmit_frame(), this is already serialized
the netdev xmit lock.
o reduce scope of tx lock in tx cleanup. tx cleanup operates on
different section of the ring than transmitting cpus and is
guarded by producer and consumer indices. This fixes a race
caused by rx softirq preemption on realtime kernels.
Signed-off-by: Dhananjay Phadke <dhananjay@...xen.com>
---
drivers/net/netxen/netxen_nic.h | 14 +----
drivers/net/netxen/netxen_nic_ethtool.c | 2 -
drivers/net/netxen/netxen_nic_init.c | 89 ++++++-----------------------
drivers/net/netxen/netxen_nic_main.c | 95 +++++++-----------------------
4 files changed, 43 insertions(+), 157 deletions(-)
diff --git a/drivers/net/netxen/netxen_nic.h b/drivers/net/netxen/netxen_nic.h
index 8b6546c..070421b 100644
--- a/drivers/net/netxen/netxen_nic.h
+++ b/drivers/net/netxen/netxen_nic.h
@@ -85,7 +85,7 @@
(sizeof(struct netxen_cmd_buffer) * adapter->max_tx_desc_count)
#define RCV_BUFFSIZE \
(sizeof(struct netxen_rx_buffer) * rcv_desc->max_rx_desc_count)
-#define find_diff_among(a,b,range) ((a)<=(b)?((b)-(a)):((b)+(range)-(a)))
+#define find_diff_among(a,b,range) ((a)<(b)?((b)-(a)):((b)+(range)-(a)))
#define NETXEN_NETDEV_STATUS 0x1
#define NETXEN_RCV_PRODUCER_OFFSET 0
@@ -204,7 +204,7 @@ enum {
? RCV_DESC_LRO : \
(RCV_DESC_NORMAL)))
-#define MAX_CMD_DESCRIPTORS 1024
+#define MAX_CMD_DESCRIPTORS 4096
#define MAX_RCV_DESCRIPTORS 16384
#define MAX_CMD_DESCRIPTORS_HOST (MAX_CMD_DESCRIPTORS / 4)
#define MAX_RCV_DESCRIPTORS_1G (MAX_RCV_DESCRIPTORS / 4)
@@ -824,9 +824,7 @@ struct netxen_adapter_stats {
u64 uphcong;
u64 upmcong;
u64 updunno;
- u64 skbfreed;
u64 txdropped;
- u64 txnullskb;
u64 csummed;
u64 no_rcv;
u64 rxbytes;
@@ -888,8 +886,6 @@ struct netxen_adapter {
int mtu;
int portnum;
- spinlock_t tx_lock;
- spinlock_t lock;
struct work_struct watchdog_task;
struct timer_list watchdog_timer;
struct work_struct tx_timeout_task;
@@ -898,16 +894,12 @@ struct netxen_adapter {
u32 cmd_producer;
__le32 *cmd_consumer;
-
u32 last_cmd_consumer;
+
u32 max_tx_desc_count;
u32 max_rx_desc_count;
u32 max_jumbo_rx_desc_count;
u32 max_lro_rx_desc_count;
- /* Num of instances active on cmd buffer ring */
- u32 proc_cmd_buf_counter;
-
- u32 num_threads, total_threads; /*Use to keep track of xmit threads */
u32 flags;
u32 irq;
diff --git a/drivers/net/netxen/netxen_nic_ethtool.c b/drivers/net/netxen/netxen_nic_ethtool.c
index 7a876f4..d324ea3 100644
--- a/drivers/net/netxen/netxen_nic_ethtool.c
+++ b/drivers/net/netxen/netxen_nic_ethtool.c
@@ -70,9 +70,7 @@ static const struct netxen_nic_stats netxen_nic_gstrings_stats[] = {
{"uphcong", NETXEN_NIC_STAT(stats.uphcong)},
{"upmcong", NETXEN_NIC_STAT(stats.upmcong)},
{"updunno", NETXEN_NIC_STAT(stats.updunno)},
- {"skb_freed", NETXEN_NIC_STAT(stats.skbfreed)},
{"tx_dropped", NETXEN_NIC_STAT(stats.txdropped)},
- {"tx_null_skb", NETXEN_NIC_STAT(stats.txnullskb)},
{"csummed", NETXEN_NIC_STAT(stats.csummed)},
{"no_rcv", NETXEN_NIC_STAT(stats.no_rcv)},
{"rx_bytes", NETXEN_NIC_STAT(stats.rxbytes)},
diff --git a/drivers/net/netxen/netxen_nic_init.c b/drivers/net/netxen/netxen_nic_init.c
index 64fc18d..fe64618 100644
--- a/drivers/net/netxen/netxen_nic_init.c
+++ b/drivers/net/netxen/netxen_nic_init.c
@@ -1197,96 +1197,50 @@ u32 netxen_process_rcv_ring(struct netxen_adapter *adapter, int ctxid, int max)
/* Process Command status ring */
int netxen_process_cmd_ring(struct netxen_adapter *adapter)
{
- u32 last_consumer;
- u32 consumer;
- int count1 = 0;
- int count2 = 0;
+ u32 last_consumer, consumer;
+ int count = 0, i;
struct netxen_cmd_buffer *buffer;
- struct pci_dev *pdev;
+ struct pci_dev *pdev = adapter->pdev;
+ struct net_device *netdev = adapter->netdev;
struct netxen_skb_frag *frag;
- u32 i;
- int done;
+ int done = 0;
- spin_lock(&adapter->tx_lock);
last_consumer = adapter->last_cmd_consumer;
- DPRINTK(INFO, "procesing xmit complete\n");
- /* we assume in this case that there is only one port and that is
- * port #1...changes need to be done in firmware to indicate port
- * number as part of the descriptor. This way we will be able to get
- * the netdev which is associated with that device.
- */
-
consumer = le32_to_cpu(*(adapter->cmd_consumer));
- if (last_consumer == consumer) { /* Ring is empty */
- DPRINTK(INFO, "last_consumer %d == consumer %d\n",
- last_consumer, consumer);
- spin_unlock(&adapter->tx_lock);
- return 1;
- }
-
- adapter->proc_cmd_buf_counter++;
- /*
- * Not needed - does not seem to be used anywhere.
- * adapter->cmd_consumer = consumer;
- */
- spin_unlock(&adapter->tx_lock);
- while ((last_consumer != consumer) && (count1 < MAX_STATUS_HANDLE)) {
+ while (last_consumer != consumer) {
buffer = &adapter->cmd_buf_arr[last_consumer];
- pdev = adapter->pdev;
if (buffer->skb) {
frag = &buffer->frag_array[0];
pci_unmap_single(pdev, frag->dma, frag->length,
PCI_DMA_TODEVICE);
frag->dma = 0ULL;
for (i = 1; i < buffer->frag_count; i++) {
- DPRINTK(INFO, "getting fragment no %d\n", i);
frag++; /* Get the next frag */
pci_unmap_page(pdev, frag->dma, frag->length,
PCI_DMA_TODEVICE);
frag->dma = 0ULL;
}
- adapter->stats.skbfreed++;
+ adapter->stats.xmitfinished++;
dev_kfree_skb_any(buffer->skb);
buffer->skb = NULL;
- } else if (adapter->proc_cmd_buf_counter == 1) {
- adapter->stats.txnullskb++;
- }
- if (unlikely(netif_queue_stopped(adapter->netdev)
- && netif_carrier_ok(adapter->netdev))
- && ((jiffies - adapter->netdev->trans_start) >
- adapter->netdev->watchdog_timeo)) {
- SCHEDULE_WORK(&adapter->tx_timeout_task);
}
last_consumer = get_next_index(last_consumer,
adapter->max_tx_desc_count);
- count1++;
+ if (++count >= MAX_STATUS_HANDLE)
+ break;
}
- count2 = 0;
- spin_lock(&adapter->tx_lock);
- if ((--adapter->proc_cmd_buf_counter) == 0) {
+ if (count) {
adapter->last_cmd_consumer = last_consumer;
- while ((adapter->last_cmd_consumer != consumer)
- && (count2 < MAX_STATUS_HANDLE)) {
- buffer =
- &adapter->cmd_buf_arr[adapter->last_cmd_consumer];
- count2++;
- if (buffer->skb)
- break;
- else
- adapter->last_cmd_consumer =
- get_next_index(adapter->last_cmd_consumer,
- adapter->max_tx_desc_count);
- }
- }
- if (count1 || count2) {
- if (netif_queue_stopped(adapter->netdev)
- && (adapter->flags & NETXEN_NETDEV_STATUS)) {
- netif_wake_queue(adapter->netdev);
- adapter->flags &= ~NETXEN_NETDEV_STATUS;
+ smp_mb();
+ if (netif_queue_stopped(netdev) && netif_running(netdev)) {
+ netif_tx_lock(netdev);
+ netif_wake_queue(netdev);
+ smp_mb();
+ netif_tx_unlock(netdev);
}
}
/*
@@ -1302,16 +1256,9 @@ int netxen_process_cmd_ring(struct netxen_adapter *adapter)
* There is still a possible race condition and the host could miss an
* interrupt. The card has to take care of this.
*/
- if (adapter->last_cmd_consumer == consumer &&
- (((adapter->cmd_producer + 1) %
- adapter->max_tx_desc_count) == adapter->last_cmd_consumer)) {
- consumer = le32_to_cpu(*(adapter->cmd_consumer));
- }
- done = (adapter->last_cmd_consumer == consumer);
+ consumer = le32_to_cpu(*(adapter->cmd_consumer));
+ done = (last_consumer == consumer);
- spin_unlock(&adapter->tx_lock);
- DPRINTK(INFO, "last consumer is %d in %s\n", last_consumer,
- __FUNCTION__);
return (done);
}
diff --git a/drivers/net/netxen/netxen_nic_main.c b/drivers/net/netxen/netxen_nic_main.c
index 9595520..dc4d593 100644
--- a/drivers/net/netxen/netxen_nic_main.c
+++ b/drivers/net/netxen/netxen_nic_main.c
@@ -317,7 +317,6 @@ netxen_nic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
adapter->ahw.pdev = pdev;
adapter->ahw.pci_func = pci_func_id;
- spin_lock_init(&adapter->tx_lock);
/* remap phys address */
mem_base = pci_resource_start(pdev, 0); /* 0 is for BAR 0 */
@@ -533,7 +532,6 @@ netxen_nic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
adapter->watchdog_timer.data = (unsigned long)adapter;
INIT_WORK(&adapter->watchdog_task, netxen_watchdog_task);
adapter->ahw.pdev = pdev;
- adapter->proc_cmd_buf_counter = 0;
adapter->ahw.revision_id = pdev->revision;
/* make sure Window == 1 */
@@ -952,41 +950,17 @@ static int netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
struct netxen_skb_frag *buffrag;
unsigned int i;
- u32 producer = 0;
+ u32 producer, consumer;
u32 saved_producer = 0;
struct cmd_desc_type0 *hwdesc;
int k;
struct netxen_cmd_buffer *pbuf = NULL;
- static int dropped_packet = 0;
int frag_count;
- u32 local_producer = 0;
- u32 max_tx_desc_count = 0;
- u32 last_cmd_consumer = 0;
int no_of_desc;
+ u32 num_txd = adapter->max_tx_desc_count;
- adapter->stats.xmitcalled++;
frag_count = skb_shinfo(skb)->nr_frags + 1;
- if (unlikely(skb->len <= 0)) {
- dev_kfree_skb_any(skb);
- adapter->stats.badskblen++;
- return NETDEV_TX_OK;
- }
-
- if (frag_count > MAX_BUFFERS_PER_CMD) {
- printk("%s: %s netxen_nic_xmit_frame: frag_count (%d) "
- "too large, can handle only %d frags\n",
- netxen_nic_driver_name, netdev->name,
- frag_count, MAX_BUFFERS_PER_CMD);
- adapter->stats.txdropped++;
- if ((++dropped_packet & 0xff) == 0xff)
- printk("%s: %s droppped packets = %d\n",
- netxen_nic_driver_name, netdev->name,
- dropped_packet);
-
- return NETDEV_TX_OK;
- }
-
/* There 4 fragments per descriptor */
no_of_desc = (frag_count + 3) >> 2;
if (netdev->features & NETIF_F_TSO) {
@@ -1001,27 +975,16 @@ static int netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
}
}
- spin_lock_bh(&adapter->tx_lock);
- if (adapter->total_threads >= MAX_XMIT_PRODUCERS) {
- goto out_requeue;
+ producer = adapter->cmd_producer;
+ smp_mb();
+ consumer = adapter->last_cmd_consumer;
+ if ((no_of_desc+2) > find_diff_among(producer, consumer, num_txd)) {
+ netif_stop_queue(netdev);
+ smp_mb();
+ return NETDEV_TX_BUSY;
}
- local_producer = adapter->cmd_producer;
- k = adapter->cmd_producer;
- max_tx_desc_count = adapter->max_tx_desc_count;
- last_cmd_consumer = adapter->last_cmd_consumer;
- if ((k + no_of_desc) >=
- ((last_cmd_consumer <= k) ? last_cmd_consumer + max_tx_desc_count :
- last_cmd_consumer)) {
- goto out_requeue;
- }
- k = get_index_range(k, max_tx_desc_count, no_of_desc);
- adapter->cmd_producer = k;
- adapter->total_threads++;
- adapter->num_threads++;
- spin_unlock_bh(&adapter->tx_lock);
/* Copy the descriptors into the hardware */
- producer = local_producer;
saved_producer = producer;
hwdesc = &hw->cmd_desc_head[producer];
memset(hwdesc, 0, sizeof(struct cmd_desc_type0));
@@ -1061,8 +1024,7 @@ static int netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
/* move to next desc. if there is a need */
if ((i & 0x3) == 0) {
k = 0;
- producer = get_next_index(producer,
- adapter->max_tx_desc_count);
+ producer = get_next_index(producer, num_txd);
hwdesc = &hw->cmd_desc_head[producer];
memset(hwdesc, 0, sizeof(struct cmd_desc_type0));
pbuf = &adapter->cmd_buf_arr[producer];
@@ -1080,7 +1042,6 @@ static int netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
buffrag->dma = temp_dma;
buffrag->length = temp_len;
- DPRINTK(INFO, "for loop. i=%d k=%d\n", i, k);
switch (k) {
case 0:
hwdesc->buffer1_length = cpu_to_le16(temp_len);
@@ -1101,7 +1062,7 @@ static int netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
}
frag++;
}
- producer = get_next_index(producer, adapter->max_tx_desc_count);
+ producer = get_next_index(producer, num_txd);
/* might change opcode to TX_TCP_LSO */
netxen_tso_check(adapter, &hw->cmd_desc_head[saved_producer], skb);
@@ -1128,7 +1089,7 @@ static int netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
/* copy the first 64 bytes */
memcpy(((void *)hwdesc) + 2,
(void *)(skb->data), first_hdr_len);
- producer = get_next_index(producer, max_tx_desc_count);
+ producer = get_next_index(producer, num_txd);
if (more_hdr) {
hwdesc = &hw->cmd_desc_head[producer];
@@ -1141,35 +1102,19 @@ static int netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
hwdesc,
(hdr_len -
first_hdr_len));
- producer = get_next_index(producer, max_tx_desc_count);
+ producer = get_next_index(producer, num_txd);
}
}
- spin_lock_bh(&adapter->tx_lock);
+ adapter->cmd_producer = producer;
adapter->stats.txbytes += skb->len;
- /* Code to update the adapter considering how many producer threads
- are currently working */
- if ((--adapter->num_threads) == 0) {
- /* This is the last thread */
- u32 crb_producer = adapter->cmd_producer;
- netxen_nic_update_cmd_producer(adapter, crb_producer);
- wmb();
- adapter->total_threads = 0;
- }
+ netxen_nic_update_cmd_producer(adapter, adapter->cmd_producer);
- adapter->stats.xmitfinished++;
+ adapter->stats.xmitcalled++;
netdev->trans_start = jiffies;
- spin_unlock_bh(&adapter->tx_lock);
return NETDEV_TX_OK;
-
-out_requeue:
- netif_stop_queue(netdev);
- adapter->flags |= NETXEN_NETDEV_STATUS;
-
- spin_unlock_bh(&adapter->tx_lock);
- return NETDEV_TX_BUSY;
}
static void netxen_watchdog(unsigned long v)
@@ -1194,9 +1139,13 @@ static void netxen_tx_timeout_task(struct work_struct *work)
printk(KERN_ERR "%s %s: transmit timeout, resetting.\n",
netxen_nic_driver_name, adapter->netdev->name);
- netxen_nic_close(adapter->netdev);
- netxen_nic_open(adapter->netdev);
+ netxen_nic_disable_int(adapter);
+ napi_disable(&adapter->napi);
+
adapter->netdev->trans_start = jiffies;
+
+ napi_enable(&adapter->napi);
+ netxen_nic_enable_int(adapter);
netif_wake_queue(adapter->netdev);
}
--
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