[PATCH] dmfe.c transmission performance patch

From: Tobias Ringstrom (tori@tellus.mine.nu)
Date: Sun Nov 19 2000 - 15:59:26 EST


[Please help me test this patch (for linux-2.4.0-test10/11)!]

This is my tx performance patch for dmfe, excluding the locking fixes,
which will appear in a separate patch. I would like feedback from testing
and code inspection. New since the last patch is the line printed when a
new card is found. (device name, MAC address, IO, IRQ)

Possible future work:
* Zero-copy transmission
* Use "new" PCI support API

/Tobias

--- dmfe.c.orig Sun Nov 19 21:43:33 2000
+++ dmfe.c Sun Nov 19 21:44:57 2000
@@ -57,6 +57,10 @@
    Resource usage cleanups.
    Report driver version to user.
 
+ Tobias Ringström <zajbot@goteborg.utfors.se> :
+ Rewrote the transmit code to actually use the ring buffer,
+ and to generate a lot fewer interrupts.
+
    TODO
 
    Implement pci_driver::suspend() and pci_driver::resume()
@@ -68,7 +72,7 @@
 
  */
 
-#define DMFE_VERSION "1.30 (June 11, 2000)"
+#define DMFE_VERSION "1.30p1 (November 15, 2000)"
 
 #include <linux/module.h>
 
@@ -108,6 +112,7 @@
 #define TX_MAX_SEND_CNT 0x1 /* Maximum tx packet per time */
 #define TX_DESC_CNT 0x10 /* Allocated Tx descriptors */
 #define RX_DESC_CNT 0x10 /* Allocated Rx descriptors */
+#define TX_IRQ_THR 12
 #define DESC_ALL_CNT TX_DESC_CNT+RX_DESC_CNT
 #define TX_BUF_ALLOC 0x600
 #define RX_ALLOC_SIZE 0x620
@@ -198,8 +203,7 @@
         struct rx_desc *first_rx_desc;
         struct rx_desc *rx_insert_ptr;
         struct rx_desc *rx_ready_ptr; /* packet come pointer */
- u32 tx_packet_cnt; /* transmitted packet count */
- u32 tx_queue_cnt; /* wait to send packet count */
+ u32 tx_live_cnt; /* number of used/live tx slots */
         u32 rx_avail_cnt; /* available rx descriptor count */
         u32 interval_rx_cnt; /* rx packet count a callback time */
 
@@ -423,9 +427,17 @@
         for (i = 0; i < 64; i++)
                 ((u16 *) db->srom)[i] = read_srom_word(pci_iobase, i);
 
+ printk(KERN_INFO "%s: Davicom DM%04lx at 0x%lx,",
+ dev->name,
+ ent->driver_data >> 16,
+ pci_iobase);
+
         /* Set Node address */
- for (i = 0; i < 6; i++)
+ for (i = 0; i < 6; i++) {
                 dev->dev_addr[i] = db->srom[20 + i];
+ printk("%c%02x", i ? ':' : ' ', dev->dev_addr[i]);
+ }
+ printk(", IRQ %d\n", pci_irqline);
 
         return 0;
 
@@ -490,8 +502,6 @@
 
         /* system variable init */
         db->cr6_data = CR6_DEFAULT | dmfe_cr6_user_set;
- db->tx_packet_cnt = 0;
- db->tx_queue_cnt = 0;
         db->rx_avail_cnt = 0;
         db->link_failed = 0;
         db->wait_reset = 0;
@@ -595,46 +605,38 @@
 {
         struct dmfe_board_info *db = dev->priv;
         struct tx_desc *txptr;
+ static unsigned pkt_num = TX_IRQ_THR;
 
         DMFE_DBUG(0, "dmfe_start_xmit", 0);
-
- netif_stop_queue(dev);
-
- /* Too large packet check */
- if (skb->len > MAX_PACKET_SIZE) {
- printk(KERN_ERR "%s: oversized frame (%d bytes) for transmit.\n", dev->name, (u16) skb->len);
- dev_kfree_skb(skb);
- return 0;
- }
- /* No Tx resource check, it never happen nromally */
- if (db->tx_packet_cnt >= TX_FREE_DESC_CNT) {
- return 1;
- }
 
         /* transmit this packet */
         txptr = db->tx_insert_ptr;
         memcpy((char *) txptr->tx_buf_ptr, (char *) skb->data, skb->len);
- txptr->tdes1 = 0xe1000000 | skb->len;
+ if (--pkt_num == 0)
+ {
+ txptr->tdes1 = 0xe1000000 | skb->len;
+ pkt_num = TX_IRQ_THR;
+ }
+ else
+ txptr->tdes1 = 0x61000000 | skb->len;
+
+ /* Transmit Packet Process */
+ txptr->tdes0 = 0x80000000; /* set owner bit to DM910X */
+ outl(0x1, dev->base_addr + DCR1); /* Issue Tx polling comand */
+ dev->trans_start = jiffies; /* saved the time stamp */
 
         /* Point to next transmit free descriptor */
- db->tx_insert_ptr = (struct tx_desc *) txptr->next_tx_desc;
+ txptr = (struct tx_desc *)txptr->next_tx_desc;
 
- /* Transmit Packet Process */
- if (db->tx_packet_cnt < TX_MAX_SEND_CNT) {
- txptr->tdes0 = 0x80000000; /* set owner bit to DM910X */
- db->tx_packet_cnt++; /* Ready to send count */
- outl(0x1, dev->base_addr + DCR1); /* Issue Tx polling comand */
- } else {
- db->tx_queue_cnt++; /* queue the tx packet */
- outl(0x1, dev->base_addr + DCR1); /* Issue Tx polling comand */
- }
+ if (txptr->tdes0 & 0x80000000)
+ netif_stop_queue(dev);
 
- /* Tx resource check */
- if (db->tx_packet_cnt < TX_FREE_DESC_CNT)
- netif_wake_queue(dev);
+ db->tx_insert_ptr = txptr;
+ db->tx_live_cnt++;
 
         /* free this SKB */
         dev_kfree_skb(skb);
+
         return 0;
 }
 
@@ -713,12 +715,12 @@
                 outl(0, ioaddr + DCR7); /* disable all interrupt */
                 return;
         }
+
         /* Free the transmitted descriptor */
         txptr = db->tx_remove_ptr;
- while (db->tx_packet_cnt) {
+ while (db->tx_live_cnt > 0 && (txptr->tdes0 & 0x80000000) == 0)
+ {
                 /* printk("tdes0=%x\n", txptr->tdes0); */
- if (txptr->tdes0 & 0x80000000)
- break;
                 db->stats.tx_packets++;
                 
                 if ((txptr->tdes0 & TDES0_ERR_MASK) && (txptr->tdes0 != 0x7fffffff)) {
@@ -734,21 +736,12 @@
                                 db->stats.tx_errors++;
                 }
                 txptr = (struct tx_desc *) txptr->next_tx_desc;
- db->tx_packet_cnt--;
+ db->tx_live_cnt--;
         }
         /* Update TX remove pointer to next */
         db->tx_remove_ptr = (struct tx_desc *) txptr;
 
- /* Send the Tx packet in queue */
- if ((db->tx_packet_cnt < TX_MAX_SEND_CNT) && db->tx_queue_cnt) {
- txptr->tdes0 = 0x80000000; /* set owner bit to DM910X */
- db->tx_packet_cnt++; /* Ready to send count */
- outl(0x1, ioaddr + DCR1); /* Issue Tx polling command */
- dev->trans_start = jiffies; /* saved the time stamp */
- db->tx_queue_cnt--;
- }
- /* Resource available check */
- if (db->tx_packet_cnt < TX_FREE_DESC_CNT)
+ if ((db->tx_insert_ptr->tdes0 & 0x80000000) == 0)
                 netif_wake_queue(dev);
 
         /* Received the coming packet */
@@ -930,12 +923,14 @@
 
         db->interval_rx_cnt = 0;
 
- if (db->wait_reset | (db->tx_packet_cnt &&
- ((jiffies - dev->trans_start) > DMFE_TX_TIMEOUT)) | (db->rx_error_cnt > 3)) {
+ if (db->wait_reset ||
+ (db->tx_live_cnt > 0 &&
+ ((jiffies - dev->trans_start) > DMFE_TX_TIMEOUT)) ||
+ (db->rx_error_cnt > 3)) {
                 /*
                    printk("wait_reset %x, tx cnt %x, rx err %x, time %x\n", db->wait_reset, db->tx_packet_cnt, db->rx_error_cnt, jiffies-dev->trans_start);
                  */
- DMFE_DBUG(0, "Warn!! Warn!! Tx/Rx moniotr step1", db->tx_packet_cnt);
+ DMFE_DBUG(0, "Warn!! Warn!! Tx/Rx monitor step1", 0);
                 dmfe_dynamic_reset(dev);
                 db->timer.expires = DMFE_TIMER_WUT;
                 add_timer(&db->timer);
@@ -1022,8 +1017,7 @@
         dmfe_free_rxbuffer(db);
 
         /* system variable init */
- db->tx_packet_cnt = 0;
- db->tx_queue_cnt = 0;
+ db->tx_live_cnt = 0;
         db->rx_avail_cnt = 0;
         db->link_failed = 0;
         db->wait_reset = 0;
@@ -1182,7 +1176,7 @@
 }
 
 /* Send a setup frame for DM9102/DM9102A
- This setup frame initilize DM910X addres filter mode
+ This setup frame initilize DM910X address filter mode
  */
 static void send_filter_frame(struct net_device *dev, int mc_cnt)
 {
@@ -1198,6 +1192,12 @@
         txptr = db->tx_insert_ptr;
         suptr = (u32 *) txptr->tx_buf_ptr;
 
+ if (txptr->tdes0 & 0x80000000) {
+ printk(KERN_WARNING "%s: Too busy to send filter frame\n",
+ dev->name);
+ return;
+ }
+
         /* Node address */
         addrptr = (u16 *) dev->dev_addr;
         *suptr++ = addrptr[0];
@@ -1224,19 +1224,13 @@
         }
         /* prepare the setup frame */
         db->tx_insert_ptr = (struct tx_desc *) txptr->next_tx_desc;
+ db->tx_live_cnt++;
         txptr->tdes1 = 0x890000c0;
- /* Resource Check and Send the setup packet */
- if (!db->tx_packet_cnt) {
- /* Resource Empty */
- db->tx_packet_cnt++;
- txptr->tdes0 = 0x80000000;
- update_cr6(db->cr6_data | 0x2000, dev->base_addr);
- outl(0x1, dev->base_addr + DCR1); /* Issue Tx polling command */
- update_cr6(db->cr6_data, dev->base_addr);
- } else {
- /* Put into TX queue */
- db->tx_queue_cnt++;
- }
+ /* Send the setup packet */
+ txptr->tdes0 = 0x80000000;
+ update_cr6(db->cr6_data | 0x2000, dev->base_addr);
+ outl(0x1, dev->base_addr + DCR1); /* Issue Tx polling command */
+ update_cr6(db->cr6_data, dev->base_addr);
 }
 
 /*
@@ -1598,14 +1592,14 @@
                 break;
         }
 
+ printk (KERN_INFO
+ "Davicom DM91xx net driver, version " DMFE_VERSION "\n");
+
         rc = pci_register_driver(&dmfe_driver);
         if (rc < 0)
                 return rc;
- if (rc > 0) {
- printk (KERN_INFO "Davicom DM91xx net driver loaded, version "
- DMFE_VERSION "\n");
+ if (rc > 0)
                 return 0;
- }
         return -ENODEV;
 }
 

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This archive was generated by hypermail 2b29 : Thu Nov 23 2000 - 21:00:18 EST