[ewg] [PATCH] IPoIB 4K MTU support
Shirley Ma
mashirle at us.ibm.com
Sun Apr 20 01:52:31 PDT 2008
Hello Roland,
I recreated IPoIB 4K MTU patch. Below patch is built against 2.6.25
kernel for 2.6.26 kernel submission. Please review and integrate it.
Please let me if any problem.
Thanks
Shirley
This patch enables IPoIB 4K MTU support by using two S/G buffers when
PAGE_SIZE is less than or equal to HCA IB MTU size. The first buffer is
for IPoIB header + GRH header. The second buffer is IPoIB payload, which
is 4K-4.
Signed-off-by: Shirley Ma <xma at us.ibm.com>
---
drivers/infiniband/ulp/ipoib/ipoib.h | 50 +++++++++++++-
drivers/infiniband/ulp/ipoib/ipoib_ib.c | 86 +++++++++++++----------
drivers/infiniband/ulp/ipoib/ipoib_main.c | 19 ++++--
drivers/infiniband/ulp/ipoib/ipoib_multicast.c | 3 +-
drivers/infiniband/ulp/ipoib/ipoib_verbs.c | 15 ++++-
drivers/infiniband/ulp/ipoib/ipoib_vlan.c | 1 +
6 files changed, 125 insertions(+), 49 deletions(-)
diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h
index 73b2b17..6a05ead 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib.h
+++ b/drivers/infiniband/ulp/ipoib/ipoib.h
@@ -56,11 +56,11 @@
/* constants */
enum {
- IPOIB_PACKET_SIZE = 2048,
- IPOIB_BUF_SIZE = IPOIB_PACKET_SIZE + IB_GRH_BYTES,
-
IPOIB_ENCAP_LEN = 4,
+ IPOIB_UD_HEAD_SIZE = IB_GRH_BYTES + IPOIB_ENCAP_LEN,
+ IPOIB_UD_RX_SG = 2, /* max buffer needed for 4K mtu */
+
IPOIB_CM_MTU = 0x10000 - 0x10, /* padding to align header to 16 */
IPOIB_CM_BUF_SIZE = IPOIB_CM_MTU + IPOIB_ENCAP_LEN,
IPOIB_CM_HEAD_SIZE = IPOIB_CM_BUF_SIZE % PAGE_SIZE,
@@ -139,7 +139,7 @@ struct ipoib_mcast {
struct ipoib_rx_buf {
struct sk_buff *skb;
- u64 mapping;
+ u64 mapping[IPOIB_UD_RX_SG];
};
struct ipoib_tx_buf {
@@ -294,6 +294,7 @@ struct ipoib_dev_priv {
unsigned int admin_mtu;
unsigned int mcast_mtu;
+ unsigned int max_ib_mtu;
struct ipoib_rx_buf *rx_ring;
@@ -305,6 +306,9 @@ struct ipoib_dev_priv {
struct ib_send_wr tx_wr;
unsigned tx_outstanding;
+ struct ib_recv_wr rx_wr;
+ struct ib_sge rx_sge[IPOIB_UD_RX_SG];
+
struct ib_wc ibwc[IPOIB_NUM_WC];
struct list_head dead_ahs;
@@ -366,6 +370,44 @@ struct ipoib_neigh {
struct list_head list;
};
+#define IPOIB_UD_MTU(ib_mtu) (ib_mtu - IPOIB_ENCAP_LEN)
+#define IPOIB_UD_BUF_SIZE(ib_mtu) (ib_mtu + IB_GRH_BYTES)
+
+static inline int ipoib_ud_need_sg(unsigned int ib_mtu)
+{
+ return (IPOIB_UD_BUF_SIZE(ib_mtu) > PAGE_SIZE) ? 1 : 0;
+}
+
+static inline void ipoib_ud_dma_unmap_rx(struct ipoib_dev_priv *priv,
+ u64 mapping[IPOIB_UD_RX_SG])
+{
+ if (ipoib_ud_need_sg(priv->max_ib_mtu)) {
+ ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_UD_HEAD_SIZE, DMA_FROM_DEVICE);
+ ib_dma_unmap_page(priv->ca, mapping[1], PAGE_SIZE, DMA_FROM_DEVICE);
+ } else
+ ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_UD_BUF_SIZE(priv->max_ib_mtu), DMA_FROM_DEVICE);
+}
+
+static inline void ipoib_ud_skb_put_frags(struct ipoib_dev_priv *priv,
+ struct sk_buff *skb,
+ unsigned int length)
+{
+ if (ipoib_ud_need_sg(priv->max_ib_mtu)) {
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[0];
+ /*
+ * There is only two buffers needed for max_payload = 4K,
+ * first buf size is IPOIB_UD_HEAD_SIZE
+ */
+ skb->tail += IPOIB_UD_HEAD_SIZE;
+ frag->size = length - IPOIB_UD_HEAD_SIZE;
+ skb->data_len += frag->size;
+ skb->truesize += frag->size;
+ skb->len += length;
+ } else
+ skb_put(skb, length);
+
+}
+
/*
* We stash a pointer to our private neighbour information after our
* hardware address in neigh->ha. The ALIGN() expression here makes
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
index 0205eb7..8b3f1b2 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
@@ -92,25 +92,18 @@ void ipoib_free_ah(struct kref *kref)
static int ipoib_ib_post_receive(struct net_device *dev, int id)
{
struct ipoib_dev_priv *priv = netdev_priv(dev);
- struct ib_sge list;
- struct ib_recv_wr param;
struct ib_recv_wr *bad_wr;
int ret;
- list.addr = priv->rx_ring[id].mapping;
- list.length = IPOIB_BUF_SIZE;
- list.lkey = priv->mr->lkey;
+ priv->rx_wr.wr_id = id | IPOIB_OP_RECV;
+ priv->rx_sge[0].addr = priv->rx_ring[id].mapping[0];
+ priv->rx_sge[1].addr = priv->rx_ring[id].mapping[1];
+
- param.next = NULL;
- param.wr_id = id | IPOIB_OP_RECV;
- param.sg_list = &list;
- param.num_sge = 1;
-
- ret = ib_post_recv(priv->qp, ¶m, &bad_wr);
+ ret = ib_post_recv(priv->qp, &priv->rx_wr, &bad_wr);
if (unlikely(ret)) {
ipoib_warn(priv, "receive failed for buf %d (%d)\n", id, ret);
- ib_dma_unmap_single(priv->ca, priv->rx_ring[id].mapping,
- IPOIB_BUF_SIZE, DMA_FROM_DEVICE);
+ ipoib_ud_dma_unmap_rx(priv, priv->rx_ring[id].mapping);
dev_kfree_skb_any(priv->rx_ring[id].skb);
priv->rx_ring[id].skb = NULL;
}
@@ -118,15 +111,22 @@ static int ipoib_ib_post_receive(struct net_device *dev, int id)
return ret;
}
-static int ipoib_alloc_rx_skb(struct net_device *dev, int id)
+static struct sk_buff *ipoib_alloc_rx_skb(struct net_device *dev,
+ int id,
+ u64 mapping[IPOIB_UD_RX_SG])
{
struct ipoib_dev_priv *priv = netdev_priv(dev);
struct sk_buff *skb;
- u64 addr;
+ int buf_size;
- skb = dev_alloc_skb(IPOIB_BUF_SIZE + 4);
- if (!skb)
- return -ENOMEM;
+ if (ipoib_ud_need_sg(priv->max_ib_mtu))
+ buf_size = IPOIB_UD_HEAD_SIZE;
+ else
+ buf_size = IPOIB_UD_BUF_SIZE(priv->max_ib_mtu);
+
+ skb = dev_alloc_skb(buf_size + 4);
+ if (unlikely(!skb))
+ return NULL;
/*
* IB will leave a 40 byte gap for a GRH and IPoIB adds a 4 byte
@@ -135,17 +135,31 @@ static int ipoib_alloc_rx_skb(struct net_device *dev, int id)
*/
skb_reserve(skb, 4);
- addr = ib_dma_map_single(priv->ca, skb->data, IPOIB_BUF_SIZE,
- DMA_FROM_DEVICE);
- if (unlikely(ib_dma_mapping_error(priv->ca, addr))) {
+ mapping[0] = ib_dma_map_single(priv->ca, skb->data, buf_size,
+ DMA_FROM_DEVICE);
+ if (unlikely(ib_dma_mapping_error(priv->ca, mapping[0]))) {
dev_kfree_skb_any(skb);
- return -EIO;
+ return NULL;
+ }
+ if (ipoib_ud_need_sg(priv->max_ib_mtu)) {
+ struct page *page = alloc_page(GFP_ATOMIC);
+ if (!page)
+ goto partial_error;
+ skb_fill_page_desc(skb, 0, page, 0, PAGE_SIZE);
+ mapping[1] = ib_dma_map_page(priv->ca,
+ skb_shinfo(skb)->frags[0].page,
+ 0, PAGE_SIZE, DMA_FROM_DEVICE);
+ if (unlikely(ib_dma_mapping_error(priv->ca, mapping[1])))
+ goto partial_error;
}
- priv->rx_ring[id].skb = skb;
- priv->rx_ring[id].mapping = addr;
+ priv->rx_ring[id].skb = skb;
+ return skb;
- return 0;
+partial_error:
+ ib_dma_unmap_single(priv->ca, mapping[0], buf_size, DMA_FROM_DEVICE);
+ dev_kfree_skb_any(skb);
+ return NULL;
}
static int ipoib_ib_post_receives(struct net_device *dev)
@@ -154,7 +168,7 @@ static int ipoib_ib_post_receives(struct net_device *dev)
int i;
for (i = 0; i < ipoib_recvq_size; ++i) {
- if (ipoib_alloc_rx_skb(dev, i)) {
+ if (!ipoib_alloc_rx_skb(dev, i, priv->rx_ring[i].mapping)) {
ipoib_warn(priv, "failed to allocate receive buffer %d\n", i);
return -ENOMEM;
}
@@ -172,7 +186,7 @@ static void ipoib_ib_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
struct ipoib_dev_priv *priv = netdev_priv(dev);
unsigned int wr_id = wc->wr_id & ~IPOIB_OP_RECV;
struct sk_buff *skb;
- u64 addr;
+ u64 mapping[IPOIB_UD_RX_SG];
ipoib_dbg_data(priv, "recv completion: id %d, status: %d\n",
wr_id, wc->status);
@@ -184,15 +198,13 @@ static void ipoib_ib_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
}
skb = priv->rx_ring[wr_id].skb;
- addr = priv->rx_ring[wr_id].mapping;
if (unlikely(wc->status != IB_WC_SUCCESS)) {
if (wc->status != IB_WC_WR_FLUSH_ERR)
ipoib_warn(priv, "failed recv event "
"(status=%d, wrid=%d vend_err %x)\n",
wc->status, wr_id, wc->vendor_err);
- ib_dma_unmap_single(priv->ca, addr,
- IPOIB_BUF_SIZE, DMA_FROM_DEVICE);
+ ipoib_ud_dma_unmap_rx(priv, priv->rx_ring[wr_id].mapping);
dev_kfree_skb_any(skb);
priv->rx_ring[wr_id].skb = NULL;
return;
@@ -209,7 +221,7 @@ static void ipoib_ib_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
* If we can't allocate a new RX buffer, dump
* this packet and reuse the old buffer.
*/
- if (unlikely(ipoib_alloc_rx_skb(dev, wr_id))) {
+ if (unlikely(!ipoib_alloc_rx_skb(dev, wr_id, mapping))) {
++dev->stats.rx_dropped;
goto repost;
}
@@ -217,9 +229,11 @@ static void ipoib_ib_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
ipoib_dbg_data(priv, "received %d bytes, SLID 0x%04x\n",
wc->byte_len, wc->slid);
- ib_dma_unmap_single(priv->ca, addr, IPOIB_BUF_SIZE, DMA_FROM_DEVICE);
+ ipoib_ud_dma_unmap_rx(priv, priv->rx_ring[wr_id].mapping);
+ ipoib_ud_skb_put_frags(priv, skb, wc->byte_len);
+ memcpy(priv->rx_ring[wr_id].mapping, mapping,
+ IPOIB_UD_RX_SG * sizeof *mapping);
- skb_put(skb, wc->byte_len);
skb_pull(skb, IB_GRH_BYTES);
skb->protocol = ((struct ipoib_header *) skb->data)->proto;
@@ -733,10 +747,8 @@ int ipoib_ib_dev_stop(struct net_device *dev, int flush)
rx_req = &priv->rx_ring[i];
if (!rx_req->skb)
continue;
- ib_dma_unmap_single(priv->ca,
- rx_req->mapping,
- IPOIB_BUF_SIZE,
- DMA_FROM_DEVICE);
+ ipoib_ud_dma_unmap_rx(priv,
+ priv->rx_ring[i].mapping);
dev_kfree_skb_any(rx_req->skb);
rx_req->skb = NULL;
}
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index bd07f02..ee4c45a 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -195,7 +195,7 @@ static int ipoib_change_mtu(struct net_device *dev, int new_mtu)
return 0;
}
- if (new_mtu > IPOIB_PACKET_SIZE - IPOIB_ENCAP_LEN)
+ if (new_mtu > IPOIB_UD_MTU(priv->max_ib_mtu))
return -EINVAL;
priv->admin_mtu = new_mtu;
@@ -971,10 +971,6 @@ static void ipoib_setup(struct net_device *dev)
NETIF_F_LLTX |
NETIF_F_HIGHDMA);
- /* MTU will be reset when mcast join happens */
- dev->mtu = IPOIB_PACKET_SIZE - IPOIB_ENCAP_LEN;
- priv->mcast_mtu = priv->admin_mtu = dev->mtu;
-
memcpy(dev->broadcast, ipv4_bcast_addr, INFINIBAND_ALEN);
netif_carrier_off(dev);
@@ -1107,6 +1103,7 @@ static struct net_device *ipoib_add_port(const char *format,
{
struct ipoib_dev_priv *priv;
struct ib_device_attr *device_attr;
+ struct ib_port_attr attr;
int result = -ENOMEM;
priv = ipoib_intf_alloc(format);
@@ -1115,6 +1112,18 @@ static struct net_device *ipoib_add_port(const char *format,
SET_NETDEV_DEV(priv->dev, hca->dma_device);
+ if (!ib_query_port(hca, port, &attr))
+ priv->max_ib_mtu = ib_mtu_enum_to_int(attr.max_mtu);
+ else {
+ printk(KERN_WARNING "%s: ib_query_port %d failed\n",
+ hca->name, port);
+ goto device_init_failed;
+ }
+
+ /* MTU will be reset when mcast join happens */
+ priv->dev->mtu = IPOIB_UD_MTU(priv->max_ib_mtu);
+ priv->mcast_mtu = priv->admin_mtu = priv->dev->mtu;
+
result = ib_query_pkey(hca, port, 0, &priv->pkey);
if (result) {
printk(KERN_WARNING "%s: ib_query_pkey port %d failed (ret = %d)\n",
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 31a53c5..b9faef2 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -567,8 +567,7 @@ void ipoib_mcast_join_task(struct work_struct *work)
return;
}
- priv->mcast_mtu = ib_mtu_enum_to_int(priv->broadcast->mcmember.mtu) -
- IPOIB_ENCAP_LEN;
+ priv->mcast_mtu = IPOIB_UD_MTU(ib_mtu_enum_to_int(priv->broadcast->mcmember.mtu));
if (!ipoib_cm_admin_enabled(dev))
dev->mtu = min(priv->mcast_mtu, priv->admin_mtu);
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_verbs.c b/drivers/infiniband/ulp/ipoib/ipoib_verbs.c
index 8a20e37..a7d4bcb 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_verbs.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_verbs.c
@@ -150,7 +150,7 @@ int ipoib_transport_dev_init(struct net_device *dev, struct ib_device *ca)
.max_send_wr = ipoib_sendq_size,
.max_recv_wr = ipoib_recvq_size,
.max_send_sge = 1,
- .max_recv_sge = 1
+ .max_recv_sge = IPOIB_UD_RX_SG
},
.sq_sig_type = IB_SIGNAL_ALL_WR,
.qp_type = IB_QPT_UD
@@ -215,6 +215,19 @@ int ipoib_transport_dev_init(struct net_device *dev, struct ib_device *ca)
priv->tx_wr.sg_list = priv->tx_sge;
priv->tx_wr.send_flags = IB_SEND_SIGNALED;
+ priv->rx_sge[0].lkey = priv->mr->lkey;
+ if (ipoib_ud_need_sg(priv->max_ib_mtu)) {
+ priv->rx_sge[0].length = IPOIB_UD_HEAD_SIZE;
+ priv->rx_sge[1].length = PAGE_SIZE;
+ priv->rx_sge[1].lkey = priv->mr->lkey;
+ priv->rx_wr.num_sge = IPOIB_UD_RX_SG;
+ } else {
+ priv->rx_sge[0].length = IPOIB_UD_BUF_SIZE(priv->max_ib_mtu);
+ priv->rx_wr.num_sge = 1;
+ }
+ priv->rx_wr.next = NULL;
+ priv->rx_wr.sg_list = priv->rx_sge;
+
return 0;
out_free_cq:
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
index 293f5b8..431fdea 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
@@ -89,6 +89,7 @@ int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey)
goto err;
}
+ priv->max_ib_mtu = ppriv->max_ib_mtu;
set_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags);
priv->pkey = pkey;
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