[RFC,11/17] venet: add scatter-gather support

Message ID	20090331184344.28333.53834.stgit@dev.haskins.net (mailing list archive)
State	Not Applicable
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n2VIhtuS031902 for <patchwork-kvm@patchwork.kernel.org>; Tue, 31 Mar 2009 18:43:57 GMT From: Gregory Haskins <ghaskins@novell.com> Subject: [RFC PATCH 11/17] venet: add scatter-gather support To: linux-kernel@vger.kernel.org Cc: agraf@suse.de, pmullaney@novell.com, pmorreale@novell.com, anthony@codemonkey.ws, rusty@rustcorp.com.au, netdev@vger.kernel.org, kvm@vger.kernel.org Date: Tue, 31 Mar 2009 14:43:44 -0400 Message-ID: <20090331184344.28333.53834.stgit@dev.haskins.net> In-Reply-To: <20090331184057.28333.77287.stgit@dev.haskins.net> References: <20090331184057.28333.77287.stgit@dev.haskins.net> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org Precedence: bulk

diff --git a/drivers/net/vbus-enet.c b/drivers/net/vbus-enet.c index e698b3f..8e96c9c 100644 --- a/drivers/net/vbus-enet.c +++ b/drivers/net/vbus-enet.c @@ -42,6 +42,8 @@ static int rx_ringlen = 256; module_param(rx_ringlen, int, 0444); static int tx_ringlen = 256; module_param(tx_ringlen, int, 0444); +static int sg_enabled = 1; +module_param(sg_enabled, int, 0444); #undef PDEBUG /* undef it, just in case */ #ifdef VBUS_ENET_DEBUG @@ -64,8 +66,17 @@ struct vbus_enet_priv { struct vbus_enet_queue rxq; struct vbus_enet_queue txq; struct tasklet_struct txtask; + struct { + int sg:1; + int tso:1; + int ufo:1; + int tso6:1; + int ecn:1; + } flags; }; +static void vbus_enet_tx_reap(struct vbus_enet_priv *priv, int force); + static struct vbus_enet_priv * napi_to_priv(struct napi_struct *napi) { @@ -199,6 +210,93 @@ rx_teardown(struct vbus_enet_priv *priv) } } +static int +tx_setup(struct vbus_enet_priv *priv) +{ + struct ioq *ioq = priv->txq.queue; + struct ioq_iterator iter; + int i; + int ret; + + if (!priv->flags.sg) + /* + * There is nothing to do for a ring that is not using + * scatter-gather + */ + return 0; + + ret = ioq_iter_init(ioq, &iter, ioq_idxtype_valid, 0); + BUG_ON(ret < 0); + + ret = ioq_iter_seek(&iter, ioq_seek_set, 0, 0); + BUG_ON(ret < 0); + + /* + * Now populate each descriptor with an empty SG descriptor + */ + for (i = 0; i < tx_ringlen; i++) { + struct venet_sg *vsg; + size_t iovlen = sizeof(struct venet_iov) * (MAX_SKB_FRAGS-1); + size_t len = sizeof(*vsg) + iovlen; + + vsg = kzalloc(len, GFP_KERNEL); + if (!vsg) + return -ENOMEM; + + iter.desc->cookie = (u64)vsg; + iter.desc->len = len; + iter.desc->ptr = (u64)__pa(vsg); + + ret = ioq_iter_seek(&iter, ioq_seek_next, 0, 0); + BUG_ON(ret < 0); + } + + return 0; +} + +static void +tx_teardown(struct vbus_enet_priv *priv) +{ + struct ioq *ioq = priv->txq.queue; + struct ioq_iterator iter; + int ret; + + /* forcefully free all outstanding transmissions */ + vbus_enet_tx_reap(priv, 1); + + if (!priv->flags.sg) + /* + * There is nothing else to do for a ring that is not using + * scatter-gather + */ + return; + + ret = ioq_iter_init(ioq, &iter, ioq_idxtype_valid, 0); + BUG_ON(ret < 0); + + /* seek to position 0 */ + ret = ioq_iter_seek(&iter, ioq_seek_set, 0, 0); + BUG_ON(ret < 0); + + /* + * free each valid descriptor + */ + while (iter.desc->cookie) { + struct venet_sg *vsg = (struct venet_sg *)iter.desc->cookie; + + iter.desc->valid = 0; + wmb(); + + iter.desc->ptr = 0; + iter.desc->cookie = 0; + + ret = ioq_iter_seek(&iter, ioq_seek_next, 0, 0); + BUG_ON(ret < 0); + + kfree(vsg); + } +} + /* * Open and close */ @@ -403,14 +501,67 @@ vbus_enet_tx_start(struct sk_buff *skb, struct net_device *dev) BUG_ON(ret < 0); BUG_ON(iter.desc->sown); - /* - * We simply put the skb right onto the ring. We will get an interrupt - * later when the data has been consumed and we can reap the pointers - * at that time - */ - iter.desc->cookie = (u64)skb; - iter.desc->len = (u64)skb->len; - iter.desc->ptr = (u64)__pa(skb->data); + if (priv->flags.sg) { + struct venet_sg *vsg = (struct venet_sg *)iter.desc->cookie; + struct scatterlist sgl[MAX_SKB_FRAGS+1]; + struct scatterlist *sg; + int count, maxcount = ARRAY_SIZE(sgl); + + sg_init_table(sgl, maxcount); + + memset(vsg, 0, sizeof(*vsg)); + + vsg->cookie = (u64)skb; + vsg->len = skb->len; + + if (skb->ip_summed == CHECKSUM_PARTIAL) { + vsg->flags |= VENET_SG_FLAG_NEEDS_CSUM; + vsg->csum.start = skb->csum_start - skb_headroom(skb); + vsg->csum.offset = skb->csum_offset; + } + + if (skb_is_gso(skb)) { + struct skb_shared_info *sinfo = skb_shinfo(skb); + + vsg->flags |= VENET_SG_FLAG_GSO; + + vsg->gso.hdrlen = skb_transport_header(skb) - skb->data; + vsg->gso.size = sinfo->gso_size; + if (sinfo->gso_type & SKB_GSO_TCPV4) + vsg->gso.type = VENET_GSO_TYPE_TCPV4; + else if (sinfo->gso_type & SKB_GSO_TCPV6) + vsg->gso.type = VENET_GSO_TYPE_TCPV6; + else if (sinfo->gso_type & SKB_GSO_UDP) + vsg->gso.type = VENET_GSO_TYPE_UDP; + else + panic("Virtual-Ethernet: unknown GSO type " \ + "0x%x\n", sinfo->gso_type); + + if (sinfo->gso_type & SKB_GSO_TCP_ECN) + vsg->flags |= VENET_SG_FLAG_ECN; + } + + count = skb_to_sgvec(skb, sgl, 0, skb->len); + + BUG_ON(count > maxcount); + + for (sg = &sgl[0]; sg; sg = sg_next(sg)) { + struct venet_iov *iov = &vsg->iov[vsg->count++]; + + iov->len = sg->length; + iov->ptr = (u64)sg_phys(sg); + } + + } else { + /* + * non scatter-gather mode: simply put the skb right onto the + * ring. + */ + iter.desc->cookie = (u64)skb; + iter.desc->len = (u64)skb->len; + iter.desc->ptr = (u64)__pa(skb->data); + } + iter.desc->valid = 1; priv->stats.tx_packets++; @@ -466,7 +617,17 @@ vbus_enet_tx_reap(struct vbus_enet_priv *priv, int force) * owned by the south-side */ while (iter.desc->valid && (!iter.desc->sown || force)) { - struct sk_buff *skb = (struct sk_buff *)iter.desc->cookie; + struct sk_buff *skb; + + if (priv->flags.sg) { + struct venet_sg *vsg; + + vsg = (struct venet_sg *)iter.desc->cookie; + skb = (struct sk_buff *)vsg->cookie; + + } else { + skb = (struct sk_buff *)iter.desc->cookie; + } PDEBUG("%lld: completed sending %d bytes\n", priv->vdev->id, skb->len); @@ -567,6 +728,47 @@ tx_isr(struct ioq_notifier *notifier) tasklet_schedule(&priv->txtask); } +static int +vbus_enet_negcap(struct vbus_enet_priv *priv) +{ + int ret; + struct venet_capabilities caps; + + memset(&caps, 0, sizeof(caps)); + + if (sg_enabled) { + caps.gid = VENET_CAP_GROUP_SG; + caps.bits |= (VENET_CAP_SG|VENET_CAP_TSO4|VENET_CAP_TSO6 + |VENET_CAP_ECN|VENET_CAP_UFO); + } + + ret = devcall(priv, VENET_FUNC_NEGCAP, &caps, sizeof(caps)); + if (ret < 0) + return ret; + + if (caps.bits & VENET_CAP_SG) { + priv->flags.sg = true; + + if (caps.bits & VENET_CAP_TSO4) + priv->flags.tso = true; + if (caps.bits & VENET_CAP_TSO6) + priv->flags.tso6 = true; + if (caps.bits & VENET_CAP_UFO) + priv->flags.ufo = true; + if (caps.bits & VENET_CAP_ECN) + priv->flags.ecn = true; + + printk(KERN_INFO "VBUSENET %lld: " \ + "Detected GSO features %s%s%s%s\n", priv->vdev->id, + priv->flags.tso ? "t" : "-", + priv->flags.tso6 ? "T" : "-", + priv->flags.ufo ? "u" : "-", + priv->flags.ecn ? "e" : "-"); + } + + return 0; +} + static struct net_device_ops vbus_enet_netdev_ops = { .ndo_open = vbus_enet_open, .ndo_stop = vbus_enet_stop, @@ -606,12 +808,21 @@ vbus_enet_probe(struct vbus_device_proxy *vdev) priv->dev = dev; priv->vdev = vdev; + ret = vbus_enet_negcap(priv); + if (ret < 0) { + printk(KERN_INFO "VENET: Error negotiating capabilities for " \ + "%lld\n", + priv->vdev->id); + goto out_free; + } + tasklet_init(&priv->txtask, deferred_tx_isr, (unsigned long)priv); queue_init(priv, &priv->rxq, VENET_QUEUE_RX, rx_ringlen, rx_isr); queue_init(priv, &priv->txq, VENET_QUEUE_TX, tx_ringlen, tx_isr); rx_setup(priv); + tx_setup(priv); ioq_notify_enable(priv->rxq.queue, 0); /* enable interrupts */ ioq_notify_enable(priv->txq.queue, 0); @@ -633,6 +844,22 @@ vbus_enet_probe(struct vbus_device_proxy *vdev) dev->features |= NETIF_F_HIGHDMA; + if (priv->flags.sg) { + dev->features |= NETIF_F_SG|NETIF_F_HW_CSUM|NETIF_F_FRAGLIST; + + if (priv->flags.tso) + dev->features |= NETIF_F_TSO; + + if (priv->flags.ufo) + dev->features |= NETIF_F_UFO; + + if (priv->flags.tso6) + dev->features |= NETIF_F_TSO6; + + if (priv->flags.ecn) + dev->features |= NETIF_F_TSO_ECN; + } + ret = register_netdev(dev); if (ret < 0) { printk(KERN_INFO "VENET: error %i registering device \"%s\"\n", @@ -660,9 +887,9 @@ vbus_enet_remove(struct vbus_device_proxy *vdev) napi_disable(&priv->napi); rx_teardown(priv); - vbus_enet_tx_reap(priv, 1); - ioq_put(priv->rxq.queue); + + tx_teardown(priv); ioq_put(priv->txq.queue); dev->ops->close(dev, 0); diff --git a/include/linux/venet.h b/include/linux/venet.h index ef6b199..1c96b90 100644 --- a/include/linux/venet.h +++ b/include/linux/venet.h @@ -35,8 +35,43 @@ struct venet_capabilities { __u32 bits; }; -/* CAPABILITIES-GROUP 0 */ -/* #define VENET_CAP_FOO 0 (No capabilities defined yet, for now) */ +#define VENET_CAP_GROUP_SG 0 + +/* CAPABILITIES-GROUP SG */ +#define VENET_CAP_SG (1 << 0) +#define VENET_CAP_TSO4 (1 << 1) +#define VENET_CAP_TSO6 (1 << 2) +#define VENET_CAP_ECN (1 << 3) +#define VENET_CAP_UFO (1 << 4) + +struct venet_iov { + __u32 len; + __u64 ptr; +}; + +#define VENET_SG_FLAG_NEEDS_CSUM (1 << 0) +#define VENET_SG_FLAG_GSO (1 << 1) +#define VENET_SG_FLAG_ECN (1 << 2) + +struct venet_sg { + __u64 cookie; + __u32 flags; + __u32 len; /* total length of all iovs */ + struct { + __u16 start; /* csum starting position */ + __u16 offset; /* offset to place csum */ + } csum; + struct { +#define VENET_GSO_TYPE_TCPV4 0 /* IPv4 TCP (TSO) */ +#define VENET_GSO_TYPE_UDP 1 /* IPv4 UDP (UFO) */ +#define VENET_GSO_TYPE_TCPV6 2 /* IPv6 TCP */ + __u8 type; + __u16 hdrlen; + __u16 size; + } gso; + __u32 count; /* nr of iovs */ + struct venet_iov iov[1]; +}; #define VENET_FUNC_LINKUP 0 #define VENET_FUNC_LINKDOWN 1

[RFC,11/17] venet: add scatter-gather support

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