myri10ge: Convert from LRO to GRO
authorAndrew Gallatin <gallatin@myri.com>
Fri, 30 Nov 2012 08:31:58 +0000 (08:31 +0000)
committerDavid S. Miller <davem@davemloft.net>
Fri, 30 Nov 2012 18:44:04 +0000 (13:44 -0500)
Convert myri10ge from LRO to GRO, and simplify the driver by removing
various LRO-related code which is no longer needed including
ndo_fix_features op, custom skb building from frags, and LRO
header parsing.

Signed-off-by: Andrew Gallatin <gallatin@myri.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/myricom/Kconfig
drivers/net/ethernet/myricom/myri10ge/myri10ge.c

index 540f0c6..3932d08 100644 (file)
@@ -23,7 +23,6 @@ config MYRI10GE
        depends on PCI && INET
        select FW_LOADER
        select CRC32
-       select INET_LRO
        ---help---
          This driver supports Myricom Myri-10G Dual Protocol interface in
          Ethernet mode. If the eeprom on your board is not recent enough,
index 83516e3..84207c0 100644 (file)
@@ -50,7 +50,6 @@
 #include <linux/etherdevice.h>
 #include <linux/if_ether.h>
 #include <linux/if_vlan.h>
-#include <linux/inet_lro.h>
 #include <linux/dca.h>
 #include <linux/ip.h>
 #include <linux/inet.h>
@@ -96,8 +95,6 @@ MODULE_LICENSE("Dual BSD/GPL");
 
 #define MYRI10GE_EEPROM_STRINGS_SIZE 256
 #define MYRI10GE_MAX_SEND_DESC_TSO ((65536 / 2048) * 2)
-#define MYRI10GE_MAX_LRO_DESCRIPTORS 8
-#define MYRI10GE_LRO_MAX_PKTS 64
 
 #define MYRI10GE_NO_CONFIRM_DATA htonl(0xffffffff)
 #define MYRI10GE_NO_RESPONSE_RESULT 0xffffffff
@@ -165,8 +162,6 @@ struct myri10ge_rx_done {
        dma_addr_t bus;
        int cnt;
        int idx;
-       struct net_lro_mgr lro_mgr;
-       struct net_lro_desc lro_desc[MYRI10GE_MAX_LRO_DESCRIPTORS];
 };
 
 struct myri10ge_slice_netstats {
@@ -338,11 +333,6 @@ static int myri10ge_debug = -1;    /* defaults above */
 module_param(myri10ge_debug, int, 0);
 MODULE_PARM_DESC(myri10ge_debug, "Debug level (0=none,...,16=all)");
 
-static int myri10ge_lro_max_pkts = MYRI10GE_LRO_MAX_PKTS;
-module_param(myri10ge_lro_max_pkts, int, S_IRUGO);
-MODULE_PARM_DESC(myri10ge_lro_max_pkts,
-                "Number of LRO packets to be aggregated");
-
 static int myri10ge_fill_thresh = 256;
 module_param(myri10ge_fill_thresh, int, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(myri10ge_fill_thresh, "Number of empty rx slots allowed");
@@ -1197,36 +1187,6 @@ static inline void myri10ge_vlan_ip_csum(struct sk_buff *skb, __wsum hw_csum)
        }
 }
 
-static inline void
-myri10ge_rx_skb_build(struct sk_buff *skb, u8 * va,
-                     struct skb_frag_struct *rx_frags, int len, int hlen)
-{
-       struct skb_frag_struct *skb_frags;
-
-       skb->len = skb->data_len = len;
-       /* attach the page(s) */
-
-       skb_frags = skb_shinfo(skb)->frags;
-       while (len > 0) {
-               memcpy(skb_frags, rx_frags, sizeof(*skb_frags));
-               len -= skb_frag_size(rx_frags);
-               skb_frags++;
-               rx_frags++;
-               skb_shinfo(skb)->nr_frags++;
-       }
-
-       /* pskb_may_pull is not available in irq context, but
-        * skb_pull() (for ether_pad and eth_type_trans()) requires
-        * the beginning of the packet in skb_headlen(), move it
-        * manually */
-       skb_copy_to_linear_data(skb, va, hlen);
-       skb_shinfo(skb)->frags[0].page_offset += hlen;
-       skb_frag_size_sub(&skb_shinfo(skb)->frags[0], hlen);
-       skb->data_len -= hlen;
-       skb->tail += hlen;
-       skb_pull(skb, MXGEFW_PAD);
-}
-
 static void
 myri10ge_alloc_rx_pages(struct myri10ge_priv *mgp, struct myri10ge_rx_buf *rx,
                        int bytes, int watchdog)
@@ -1304,18 +1264,14 @@ myri10ge_unmap_rx_page(struct pci_dev *pdev,
        }
 }
 
-#define MYRI10GE_HLEN 64       /* The number of bytes to copy from a
-                                * page into an skb */
-
 static inline int
-myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum,
-                bool lro_enabled)
+myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum)
 {
        struct myri10ge_priv *mgp = ss->mgp;
        struct sk_buff *skb;
-       struct skb_frag_struct rx_frags[MYRI10GE_MAX_FRAGS_PER_FRAME];
+       struct skb_frag_struct *rx_frags;
        struct myri10ge_rx_buf *rx;
-       int i, idx, hlen, remainder, bytes;
+       int i, idx, remainder, bytes;
        struct pci_dev *pdev = mgp->pdev;
        struct net_device *dev = mgp->dev;
        u8 *va;
@@ -1332,67 +1288,47 @@ myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum,
        idx = rx->cnt & rx->mask;
        va = page_address(rx->info[idx].page) + rx->info[idx].page_offset;
        prefetch(va);
+
+       skb = napi_get_frags(&ss->napi);
+       if (unlikely(skb == NULL)) {
+               ss->stats.rx_dropped++;
+               for (i = 0, remainder = len; remainder > 0; i++) {
+                       myri10ge_unmap_rx_page(pdev, &rx->info[idx], bytes);
+                       put_page(rx->info[idx].page);
+                       rx->cnt++;
+                       idx = rx->cnt & rx->mask;
+                       remainder -= MYRI10GE_ALLOC_SIZE;
+               }
+               return 0;
+       }
+       rx_frags = skb_shinfo(skb)->frags;
        /* Fill skb_frag_struct(s) with data from our receive */
        for (i = 0, remainder = len; remainder > 0; i++) {
                myri10ge_unmap_rx_page(pdev, &rx->info[idx], bytes);
-               __skb_frag_set_page(&rx_frags[i], rx->info[idx].page);
-               rx_frags[i].page_offset = rx->info[idx].page_offset;
-               if (remainder < MYRI10GE_ALLOC_SIZE)
-                       skb_frag_size_set(&rx_frags[i], remainder);
-               else
-                       skb_frag_size_set(&rx_frags[i], MYRI10GE_ALLOC_SIZE);
+               skb_fill_page_desc(skb, i, rx->info[idx].page,
+                                  rx->info[idx].page_offset,
+                                  remainder < MYRI10GE_ALLOC_SIZE ?
+                                  remainder : MYRI10GE_ALLOC_SIZE);
                rx->cnt++;
                idx = rx->cnt & rx->mask;
                remainder -= MYRI10GE_ALLOC_SIZE;
        }
 
-       if (lro_enabled) {
-               rx_frags[0].page_offset += MXGEFW_PAD;
-               skb_frag_size_sub(&rx_frags[0], MXGEFW_PAD);
-               len -= MXGEFW_PAD;
-               lro_receive_frags(&ss->rx_done.lro_mgr, rx_frags,
-                                 /* opaque, will come back in get_frag_header */
-                                 len, len,
-                                 (void *)(__force unsigned long)csum, csum);
+       /* remove padding */
+       rx_frags[0].page_offset += MXGEFW_PAD;
+       rx_frags[0].size -= MXGEFW_PAD;
+       len -= MXGEFW_PAD;
 
-               return 1;
-       }
-
-       hlen = MYRI10GE_HLEN > len ? len : MYRI10GE_HLEN;
-
-       /* allocate an skb to attach the page(s) to. This is done
-        * after trying LRO, so as to avoid skb allocation overheads */
-
-       skb = netdev_alloc_skb(dev, MYRI10GE_HLEN + 16);
-       if (unlikely(skb == NULL)) {
-               ss->stats.rx_dropped++;
-               do {
-                       i--;
-                       __skb_frag_unref(&rx_frags[i]);
-               } while (i != 0);
-               return 0;
-       }
-
-       /* Attach the pages to the skb, and trim off any padding */
-       myri10ge_rx_skb_build(skb, va, rx_frags, len, hlen);
-       if (skb_frag_size(&skb_shinfo(skb)->frags[0]) <= 0) {
-               skb_frag_unref(skb, 0);
-               skb_shinfo(skb)->nr_frags = 0;
-       } else {
-               skb->truesize += bytes * skb_shinfo(skb)->nr_frags;
+       skb->len = len;
+       skb->data_len = len;
+       skb->truesize += len;
+       if (dev->features & NETIF_F_RXCSUM) {
+               skb->ip_summed = CHECKSUM_COMPLETE;
+               skb->csum = csum;
        }
-       skb->protocol = eth_type_trans(skb, dev);
        skb_record_rx_queue(skb, ss - &mgp->ss[0]);
 
-       if (dev->features & NETIF_F_RXCSUM) {
-               if ((skb->protocol == htons(ETH_P_IP)) ||
-                   (skb->protocol == htons(ETH_P_IPV6))) {
-                       skb->csum = csum;
-                       skb->ip_summed = CHECKSUM_COMPLETE;
-               } else
-                       myri10ge_vlan_ip_csum(skb, csum);
-       }
-       netif_receive_skb(skb);
+       napi_gro_frags(&ss->napi);
        return 1;
 }
 
@@ -1480,18 +1416,11 @@ myri10ge_clean_rx_done(struct myri10ge_slice_state *ss, int budget)
        u16 length;
        __wsum checksum;
 
-       /*
-        * Prevent compiler from generating more than one ->features memory
-        * access to avoid theoretical race condition with functions that
-        * change NETIF_F_LRO flag at runtime.
-        */
-       bool lro_enabled = !!(ACCESS_ONCE(mgp->dev->features) & NETIF_F_LRO);
-
        while (rx_done->entry[idx].length != 0 && work_done < budget) {
                length = ntohs(rx_done->entry[idx].length);
                rx_done->entry[idx].length = 0;
                checksum = csum_unfold(rx_done->entry[idx].checksum);
-               rx_ok = myri10ge_rx_done(ss, length, checksum, lro_enabled);
+               rx_ok = myri10ge_rx_done(ss, length, checksum);
                rx_packets += rx_ok;
                rx_bytes += rx_ok * (unsigned long)length;
                cnt++;
@@ -1503,9 +1432,6 @@ myri10ge_clean_rx_done(struct myri10ge_slice_state *ss, int budget)
        ss->stats.rx_packets += rx_packets;
        ss->stats.rx_bytes += rx_bytes;
 
-       if (lro_enabled)
-               lro_flush_all(&rx_done->lro_mgr);
-
        /* restock receive rings if needed */
        if (ss->rx_small.fill_cnt - ss->rx_small.cnt < myri10ge_fill_thresh)
                myri10ge_alloc_rx_pages(mgp, &ss->rx_small,
@@ -1779,7 +1705,6 @@ static const char myri10ge_gstrings_slice_stats[][ETH_GSTRING_LEN] = {
        "tx_pkt_start", "tx_pkt_done", "tx_req", "tx_done",
        "rx_small_cnt", "rx_big_cnt",
        "wake_queue", "stop_queue", "tx_linearized",
-       "LRO aggregated", "LRO flushed", "LRO avg aggr", "LRO no_desc",
 };
 
 #define MYRI10GE_NET_STATS_LEN      21
@@ -1880,14 +1805,6 @@ myri10ge_get_ethtool_stats(struct net_device *netdev,
                data[i++] = (unsigned int)ss->tx.wake_queue;
                data[i++] = (unsigned int)ss->tx.stop_queue;
                data[i++] = (unsigned int)ss->tx.linearized;
-               data[i++] = ss->rx_done.lro_mgr.stats.aggregated;
-               data[i++] = ss->rx_done.lro_mgr.stats.flushed;
-               if (ss->rx_done.lro_mgr.stats.flushed)
-                       data[i++] = ss->rx_done.lro_mgr.stats.aggregated /
-                           ss->rx_done.lro_mgr.stats.flushed;
-               else
-                       data[i++] = 0;
-               data[i++] = ss->rx_done.lro_mgr.stats.no_desc;
        }
 }
 
@@ -2271,67 +2188,6 @@ static void myri10ge_free_irq(struct myri10ge_priv *mgp)
                pci_disable_msix(pdev);
 }
 
-static int
-myri10ge_get_frag_header(struct skb_frag_struct *frag, void **mac_hdr,
-                        void **ip_hdr, void **tcpudp_hdr,
-                        u64 * hdr_flags, void *priv)
-{
-       struct ethhdr *eh;
-       struct vlan_ethhdr *veh;
-       struct iphdr *iph;
-       u8 *va = skb_frag_address(frag);
-       unsigned long ll_hlen;
-       /* passed opaque through lro_receive_frags() */
-       __wsum csum = (__force __wsum) (unsigned long)priv;
-
-       /* find the mac header, aborting if not IPv4 */
-
-       eh = (struct ethhdr *)va;
-       *mac_hdr = eh;
-       ll_hlen = ETH_HLEN;
-       if (eh->h_proto != htons(ETH_P_IP)) {
-               if (eh->h_proto == htons(ETH_P_8021Q)) {
-                       veh = (struct vlan_ethhdr *)va;
-                       if (veh->h_vlan_encapsulated_proto != htons(ETH_P_IP))
-                               return -1;
-
-                       ll_hlen += VLAN_HLEN;
-
-                       /*
-                        *  HW checksum starts ETH_HLEN bytes into
-                        *  frame, so we must subtract off the VLAN
-                        *  header's checksum before csum can be used
-                        */
-                       csum = csum_sub(csum, csum_partial(va + ETH_HLEN,
-                                                          VLAN_HLEN, 0));
-               } else {
-                       return -1;
-               }
-       }
-       *hdr_flags = LRO_IPV4;
-
-       iph = (struct iphdr *)(va + ll_hlen);
-       *ip_hdr = iph;
-       if (iph->protocol != IPPROTO_TCP)
-               return -1;
-       if (ip_is_fragment(iph))
-               return -1;
-       *hdr_flags |= LRO_TCP;
-       *tcpudp_hdr = (u8 *) (*ip_hdr) + (iph->ihl << 2);
-
-       /* verify the IP checksum */
-       if (unlikely(ip_fast_csum((u8 *) iph, iph->ihl)))
-               return -1;
-
-       /* verify the  checksum */
-       if (unlikely(csum_tcpudp_magic(iph->saddr, iph->daddr,
-                                      ntohs(iph->tot_len) - (iph->ihl << 2),
-                                      IPPROTO_TCP, csum)))
-               return -1;
-
-       return 0;
-}
-
 static int myri10ge_get_txrx(struct myri10ge_priv *mgp, int slice)
 {
        struct myri10ge_cmd cmd;
@@ -2402,7 +2258,6 @@ static int myri10ge_open(struct net_device *dev)
        struct myri10ge_cmd cmd;
        int i, status, big_pow2, slice;
        u8 *itable;
-       struct net_lro_mgr *lro_mgr;
 
        if (mgp->running != MYRI10GE_ETH_STOPPED)
                return -EBUSY;
@@ -2513,19 +2368,6 @@ static int myri10ge_open(struct net_device *dev)
                        goto abort_with_rings;
                }
 
-               lro_mgr = &ss->rx_done.lro_mgr;
-               lro_mgr->dev = dev;
-               lro_mgr->features = LRO_F_NAPI;
-               lro_mgr->ip_summed = CHECKSUM_COMPLETE;
-               lro_mgr->ip_summed_aggr = CHECKSUM_UNNECESSARY;
-               lro_mgr->max_desc = MYRI10GE_MAX_LRO_DESCRIPTORS;
-               lro_mgr->lro_arr = ss->rx_done.lro_desc;
-               lro_mgr->get_frag_header = myri10ge_get_frag_header;
-               lro_mgr->max_aggr = myri10ge_lro_max_pkts;
-               lro_mgr->frag_align_pad = 2;
-               if (lro_mgr->max_aggr > MAX_SKB_FRAGS)
-                       lro_mgr->max_aggr = MAX_SKB_FRAGS;
-
                /* must happen prior to any irq */
                napi_enable(&(ss)->napi);
        }
@@ -3143,15 +2985,6 @@ static int myri10ge_set_mac_address(struct net_device *dev, void *addr)
        return 0;
 }
 
-static netdev_features_t myri10ge_fix_features(struct net_device *dev,
-       netdev_features_t features)
-{
-       if (!(features & NETIF_F_RXCSUM))
-               features &= ~NETIF_F_LRO;
-
-       return features;
-}
-
 static int myri10ge_change_mtu(struct net_device *dev, int new_mtu)
 {
        struct myri10ge_priv *mgp = netdev_priv(dev);
@@ -3878,7 +3711,6 @@ static const struct net_device_ops myri10ge_netdev_ops = {
        .ndo_get_stats64        = myri10ge_get_stats,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_change_mtu         = myri10ge_change_mtu,
-       .ndo_fix_features       = myri10ge_fix_features,
        .ndo_set_rx_mode        = myri10ge_set_multicast_list,
        .ndo_set_mac_address    = myri10ge_set_mac_address,
 };
@@ -4018,7 +3850,7 @@ static int myri10ge_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
        netdev->netdev_ops = &myri10ge_netdev_ops;
        netdev->mtu = myri10ge_initial_mtu;
-       netdev->hw_features = mgp->features | NETIF_F_LRO | NETIF_F_RXCSUM;
+       netdev->hw_features = mgp->features | NETIF_F_RXCSUM;
        netdev->features = netdev->hw_features;
 
        if (dac_enabled)