[PATCH 3/3 2.6.27 RESEND] cxgb3 - Add LRO support

From: Divy Le Ray
Date: Wed May 21 2008 - 21:57:49 EST


From: Divy Le Ray <divy@xxxxxxxxxxx>

Add LRO support.

Signed-off-by: Divy Le Ray <divy@xxxxxxxxxxx>
---

drivers/net/Kconfig | 1
drivers/net/cxgb3/adapter.h | 14 ++
drivers/net/cxgb3/common.h | 1
drivers/net/cxgb3/cxgb3_ioctl.h | 1
drivers/net/cxgb3/cxgb3_main.c | 19 +++
drivers/net/cxgb3/sge.c | 233 +++++++++++++++++++++++++++++++++++++--
drivers/net/cxgb3/t3_cpl.h | 11 ++
7 files changed, 268 insertions(+), 12 deletions(-)

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 9f6cc8a..daeb23d 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -2409,6 +2409,7 @@ config CHELSIO_T3
tristate "Chelsio Communications T3 10Gb Ethernet support"
depends on PCI
select FW_LOADER
+ select INET_LRO
help
This driver supports Chelsio T3-based gigabit and 10Gb Ethernet
adapters.
diff --git a/drivers/net/cxgb3/adapter.h b/drivers/net/cxgb3/adapter.h
index 263e4fa..2711404 100644
--- a/drivers/net/cxgb3/adapter.h
+++ b/drivers/net/cxgb3/adapter.h
@@ -42,6 +42,7 @@
#include <linux/cache.h>
#include <linux/mutex.h>
#include <linux/bitops.h>
+#include <linux/inet_lro.h>
#include "t3cdev.h"
#include <asm/io.h>

@@ -173,16 +174,29 @@ enum { /* per port SGE statistics */
SGE_PSTAT_TX_CSUM, /* # of TX checksum offloads */
SGE_PSTAT_VLANEX, /* # of VLAN tag extractions */
SGE_PSTAT_VLANINS, /* # of VLAN tag insertions */
+ SGE_PSTAT_LRO_AGGR, /* # of page chunks added to LRO sessions */
+ SGE_PSTAT_LRO_FLUSHED, /* # of flushed LRO sessions */
+ SGE_PSTAT_LRO_NO_DESC, /* # of overflown LRO sessions */

SGE_PSTAT_MAX /* must be last */
};

+#define T3_MAX_LRO_SES 8
+#define T3_MAX_LRO_MAX_PKTS 64
+
struct sge_qset { /* an SGE queue set */
struct adapter *adap;
struct napi_struct napi;
struct sge_rspq rspq;
struct sge_fl fl[SGE_RXQ_PER_SET];
struct sge_txq txq[SGE_TXQ_PER_SET];
+ struct net_lro_mgr lro_mgr;
+ struct net_lro_desc lro_desc[T3_MAX_LRO_SES];
+ struct skb_frag_struct *lro_frag_tbl;
+ int lro_nfrags;
+ int lro_enabled;
+ int lro_frag_len;
+ void *lro_va;
struct net_device *netdev;
unsigned long txq_stopped; /* which Tx queues are stopped */
struct timer_list tx_reclaim_timer; /* reclaims TX buffers */
diff --git a/drivers/net/cxgb3/common.h b/drivers/net/cxgb3/common.h
index 579bee4..d444f58 100644
--- a/drivers/net/cxgb3/common.h
+++ b/drivers/net/cxgb3/common.h
@@ -351,6 +351,7 @@ struct tp_params {

struct qset_params { /* SGE queue set parameters */
unsigned int polling; /* polling/interrupt service for rspq */
+ unsigned int lro; /* large receive offload */
unsigned int coalesce_usecs; /* irq coalescing timer */
unsigned int rspq_size; /* # of entries in response queue */
unsigned int fl_size; /* # of entries in regular free list */
diff --git a/drivers/net/cxgb3/cxgb3_ioctl.h b/drivers/net/cxgb3/cxgb3_ioctl.h
index 0a82fcd..68200a1 100644
--- a/drivers/net/cxgb3/cxgb3_ioctl.h
+++ b/drivers/net/cxgb3/cxgb3_ioctl.h
@@ -90,6 +90,7 @@ struct ch_qset_params {
int32_t fl_size[2];
int32_t intr_lat;
int32_t polling;
+ int32_t lro;
int32_t cong_thres;
};

diff --git a/drivers/net/cxgb3/cxgb3_main.c b/drivers/net/cxgb3/cxgb3_main.c
index 3a31272..5447f3e 100644
--- a/drivers/net/cxgb3/cxgb3_main.c
+++ b/drivers/net/cxgb3/cxgb3_main.c
@@ -1212,6 +1212,9 @@ static char stats_strings[][ETH_GSTRING_LEN] = {
"VLANinsertions ",
"TxCsumOffload ",
"RxCsumGood ",
+ "LroAggregated ",
+ "LroFlushed ",
+ "LroNoDesc ",
"RxDrops ",

"CheckTXEnToggled ",
@@ -1340,6 +1343,9 @@ static void get_stats(struct net_device *dev, struct ethtool_stats *stats,
*data++ = collect_sge_port_stats(adapter, pi, SGE_PSTAT_VLANINS);
*data++ = collect_sge_port_stats(adapter, pi, SGE_PSTAT_TX_CSUM);
*data++ = collect_sge_port_stats(adapter, pi, SGE_PSTAT_RX_CSUM_GOOD);
+ *data++ = collect_sge_port_stats(adapter, pi, SGE_PSTAT_LRO_AGGR);
+ *data++ = collect_sge_port_stats(adapter, pi, SGE_PSTAT_LRO_FLUSHED);
+ *data++ = collect_sge_port_stats(adapter, pi, SGE_PSTAT_LRO_NO_DESC);
*data++ = s->rx_cong_drops;

*data++ = s->num_toggled;
@@ -1558,6 +1564,13 @@ static int set_rx_csum(struct net_device *dev, u32 data)
struct port_info *p = netdev_priv(dev);

p->rx_csum_offload = data;
+ if (!data) {
+ struct adapter *adap = p->adapter;
+ int i;
+
+ for (i = p->first_qset; i < p->first_qset + p->nqsets; i++)
+ adap->sge.qs[i].lro_enabled = 0;
+ }
return 0;
}

@@ -1830,6 +1843,11 @@ static int cxgb_extension_ioctl(struct net_device *dev, void __user *useraddr)
}
}
}
+ if (t.lro >= 0) {
+ struct sge_qset *qs = &adapter->sge.qs[t.qset_idx];
+ q->lro = t.lro;
+ qs->lro_enabled = t.lro;
+ }
break;
}
case CHELSIO_GET_QSET_PARAMS:{
@@ -1849,6 +1867,7 @@ static int cxgb_extension_ioctl(struct net_device *dev, void __user *useraddr)
t.fl_size[0] = q->fl_size;
t.fl_size[1] = q->jumbo_size;
t.polling = q->polling;
+ t.lro = q->lro;
t.intr_lat = q->coalesce_usecs;
t.cong_thres = q->cong_thres;

diff --git a/drivers/net/cxgb3/sge.c b/drivers/net/cxgb3/sge.c
index 3e91be5..a96331c 100644
--- a/drivers/net/cxgb3/sge.c
+++ b/drivers/net/cxgb3/sge.c
@@ -584,6 +584,8 @@ static void t3_reset_qset(struct sge_qset *q)
memset(q->txq, 0, sizeof(struct sge_txq) * SGE_TXQ_PER_SET);
q->txq_stopped = 0;
memset(&q->tx_reclaim_timer, 0, sizeof(q->tx_reclaim_timer));
+ kfree(q->lro_frag_tbl);
+ q->lro_nfrags = q->lro_frag_len = 0;
}


@@ -796,7 +798,7 @@ recycle:
goto recycle;

if (!skb)
- newskb = alloc_skb(SGE_RX_PULL_LEN, GFP_ATOMIC);
+ newskb = alloc_skb(SGE_RX_PULL_LEN, GFP_ATOMIC);
if (unlikely(!newskb)) {
if (!drop_thres)
return NULL;
@@ -1868,9 +1870,10 @@ static void restart_tx(struct sge_qset *qs)
* if it was immediate data in a response.
*/
static void rx_eth(struct adapter *adap, struct sge_rspq *rq,
- struct sk_buff *skb, int pad)
+ struct sk_buff *skb, int pad, int lro)
{
struct cpl_rx_pkt *p = (struct cpl_rx_pkt *)(skb->data + pad);
+ struct sge_qset *qs = rspq_to_qset(rq);
struct port_info *pi;

skb_pull(skb, sizeof(*p) + pad);
@@ -1887,18 +1890,202 @@ static void rx_eth(struct adapter *adap, struct sge_rspq *rq,
if (unlikely(p->vlan_valid)) {
struct vlan_group *grp = pi->vlan_grp;

- rspq_to_qset(rq)->port_stats[SGE_PSTAT_VLANEX]++;
+ qs->port_stats[SGE_PSTAT_VLANEX]++;
if (likely(grp))
- __vlan_hwaccel_rx(skb, grp, ntohs(p->vlan),
- rq->polling);
+ if (lro)
+ lro_vlan_hwaccel_receive_skb(&qs->lro_mgr, skb,
+ grp,
+ ntohs(p->vlan),
+ p);
+ else
+ __vlan_hwaccel_rx(skb, grp, ntohs(p->vlan),
+ rq->polling);
else
dev_kfree_skb_any(skb);
- } else if (rq->polling)
- netif_receive_skb(skb);
- else
+ } else if (rq->polling) {
+ if (lro)
+ lro_receive_skb(&qs->lro_mgr, skb, p);
+ else
+ netif_receive_skb(skb);
+ } else
netif_rx(skb);
}

+static inline int is_eth_tcp(u32 rss)
+{
+ return G_HASHTYPE(ntohl(rss)) == RSS_HASH_4_TUPLE;
+}
+
+/**
+ * lro_frame_ok - check if an ingress packet is eligible for LRO
+ * @p: the CPL header of the packet
+ *
+ * Returns true if a received packet is eligible for LRO.
+ * The following conditions must be true:
+ * - packet is TCP/IP Ethernet II (checked elsewhere)
+ * - not an IP fragment
+ * - no IP options
+ * - TCP/IP checksums are correct
+ * - the packet is for this host
+ */
+static inline int lro_frame_ok(const struct cpl_rx_pkt *p)
+{
+ const struct ethhdr *eh = (struct ethhdr *)(p + 1);
+ const struct iphdr *ih = (struct iphdr *)(eh + 1);
+
+ return (*((u8 *)p + 1) & 0x90) == 0x10 && p->csum == htons(0xffff) &&
+ eh->h_proto == htons(ETH_P_IP) && ih->ihl == (sizeof(*ih) >> 2);
+}
+
+#define TCP_FLAG_MASK (TCP_FLAG_CWR | TCP_FLAG_ECE | TCP_FLAG_URG |\
+ TCP_FLAG_ACK | TCP_FLAG_PSH | TCP_FLAG_RST |\
+ TCP_FLAG_SYN | TCP_FLAG_FIN)
+#define TSTAMP_WORD ((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |\
+ (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)
+
+/**
+ * lro_segment_ok - check if a TCP segment is eligible for LRO
+ * @tcph: the TCP header of the packet
+ *
+ * Returns true if a TCP packet is eligible for LRO. This requires that
+ * the packet have only the ACK flag set and no TCP options besides
+ * time stamps.
+ */
+static inline int lro_segment_ok(const struct tcphdr *tcph)
+{
+ int optlen;
+
+ if (unlikely((tcp_flag_word(tcph) & TCP_FLAG_MASK) != TCP_FLAG_ACK))
+ return 0;
+
+ optlen = (tcph->doff << 2) - sizeof(*tcph);
+ if (optlen) {
+ const u32 *opt = (const u32 *)(tcph + 1);
+
+ if (optlen != TCPOLEN_TSTAMP_ALIGNED ||
+ *opt != htonl(TSTAMP_WORD) || !opt[2])
+ return 0;
+ }
+ return 1;
+}
+
+static int t3_get_lro_header(void **eh, void **iph, void **tcph,
+ u64 *hdr_flags, void *priv)
+{
+ const struct cpl_rx_pkt *cpl = priv;
+
+ if (!lro_frame_ok(cpl))
+ return -1;
+
+ *eh = (struct ethhdr *)(cpl + 1);
+ *iph = (struct iphdr *)((struct ethhdr *)*eh + 1);
+ *tcph = (struct tcphdr *)((struct iphdr *)*iph + 1);
+
+ if (!lro_segment_ok(*tcph))
+ return -1;
+
+ *hdr_flags = LRO_IPV4 | LRO_TCP;
+ return 0;
+}
+
+static int t3_get_skb_header(struct sk_buff *skb,
+ void **iph, void **tcph, u64 *hdr_flags,
+ void *priv)
+{
+ void *eh;
+
+ return t3_get_lro_header(&eh, iph, tcph, hdr_flags, priv);
+}
+
+static int t3_get_frag_header(struct skb_frag_struct *frag, void **eh,
+ void **iph, void **tcph, u64 *hdr_flags,
+ void *priv)
+{
+ return t3_get_lro_header(eh, iph, tcph, hdr_flags, priv);
+}
+
+/**
+ * lro_add_page - add a page chunk to an LRO session
+ * @adap: the adapter
+ * @qs: the associated queue set
+ * @fl: the free list containing the page chunk to add
+ * @len: packet length
+ * @complete: Indicates the last fragment of a frame
+ *
+ * Add a received packet contained in a page chunk to an existing LRO
+ * session.
+ */
+static void lro_add_page(struct adapter *adap, struct sge_qset *qs,
+ struct sge_fl *fl, int len, int complete)
+{
+ struct rx_sw_desc *sd = &fl->sdesc[fl->cidx];
+ struct cpl_rx_pkt *cpl;
+ struct skb_frag_struct *rx_frag = qs->lro_frag_tbl;
+ int nr_frags = qs->lro_nfrags, frag_len = qs->lro_frag_len;
+ int offset = 0;
+
+ if (!nr_frags) {
+ offset = 2 + sizeof(struct cpl_rx_pkt);
+ qs->lro_va = cpl = sd->pg_chunk.va + 2;
+ }
+
+ fl->credits--;
+
+ len -= offset;
+ pci_unmap_single(adap->pdev, pci_unmap_addr(sd, dma_addr),
+ fl->buf_size, PCI_DMA_FROMDEVICE);
+
+ rx_frag += nr_frags;
+ rx_frag->page = sd->pg_chunk.page;
+ rx_frag->page_offset = sd->pg_chunk.offset + offset;
+ rx_frag->size = len;
+ frag_len += len;
+ qs->lro_nfrags++;
+ qs->lro_frag_len = frag_len;
+
+ if (!complete)
+ return;
+
+ qs->lro_nfrags = qs->lro_frag_len = 0;
+ cpl = qs->lro_va;
+
+ if (unlikely(cpl->vlan_valid)) {
+ struct net_device *dev = qs->netdev;
+ struct port_info *pi = netdev_priv(dev);
+ struct vlan_group *grp = pi->vlan_grp;
+
+ if (likely(grp != NULL)) {
+ lro_vlan_hwaccel_receive_frags(&qs->lro_mgr,
+ qs->lro_frag_tbl,
+ frag_len, frag_len,
+ grp, ntohs(cpl->vlan),
+ cpl, 0);
+ return;
+ }
+ }
+ lro_receive_frags(&qs->lro_mgr, qs->lro_frag_tbl,
+ frag_len, frag_len, cpl, 0);
+}
+
+/**
+ * init_lro_mgr - initialize a LRO manager object
+ * @lro_mgr: the LRO manager object
+ */
+static void init_lro_mgr(struct sge_qset *qs, struct net_lro_mgr *lro_mgr)
+{
+ lro_mgr->dev = qs->netdev;
+ lro_mgr->features = LRO_F_NAPI;
+ lro_mgr->ip_summed = CHECKSUM_UNNECESSARY;
+ lro_mgr->ip_summed_aggr = CHECKSUM_UNNECESSARY;
+ lro_mgr->max_desc = T3_MAX_LRO_SES;
+ lro_mgr->lro_arr = qs->lro_desc;
+ lro_mgr->get_frag_header = t3_get_frag_header;
+ lro_mgr->get_skb_header = t3_get_skb_header;
+ lro_mgr->max_aggr = T3_MAX_LRO_MAX_PKTS;
+ if (lro_mgr->max_aggr > MAX_SKB_FRAGS)
+ lro_mgr->max_aggr = MAX_SKB_FRAGS;
+}
+
/**
* handle_rsp_cntrl_info - handles control information in a response
* @qs: the queue set corresponding to the response
@@ -2027,7 +2214,7 @@ static int process_responses(struct adapter *adap, struct sge_qset *qs,
q->next_holdoff = q->holdoff_tmr;

while (likely(budget_left && is_new_response(r, q))) {
- int packet_complete, eth, ethpad = 2;
+ int packet_complete, eth, ethpad = 2, lro = qs->lro_enabled;
struct sk_buff *skb = NULL;
u32 len, flags = ntohl(r->flags);
__be32 rss_hi = *(const __be32 *)r,
@@ -2059,6 +2246,9 @@ no_mem:
} else if ((len = ntohl(r->len_cq)) != 0) {
struct sge_fl *fl;

+ if (eth)
+ lro = qs->lro_enabled && is_eth_tcp(rss_hi);
+
fl = (len & F_RSPD_FLQ) ? &qs->fl[1] : &qs->fl[0];
if (fl->use_pages) {
void *addr = fl->sdesc[fl->cidx].pg_chunk.va;
@@ -2068,6 +2258,12 @@ no_mem:
prefetch(addr + L1_CACHE_BYTES);
#endif
__refill_fl(adap, fl);
+ if (lro > 0) {
+ lro_add_page(adap, qs, fl,
+ G_RSPD_LEN(len),
+ flags & F_RSPD_EOP);
+ goto next_fl;
+ }

skb = get_packet_pg(adap, fl, q,
G_RSPD_LEN(len),
@@ -2083,7 +2279,7 @@ no_mem:
q->rx_drops++;
} else if (unlikely(r->rss_hdr.opcode == CPL_TRACE_PKT))
__skb_pull(skb, 2);
-
+next_fl:
if (++fl->cidx == fl->size)
fl->cidx = 0;
} else
@@ -2113,7 +2309,7 @@ no_mem:

if (skb != NULL && packet_complete) {
if (eth)
- rx_eth(adap, q, skb, ethpad);
+ rx_eth(adap, q, skb, ethpad, lro);
else {
q->offload_pkts++;
/* Preserve the RSS info in csum & priority */
@@ -2125,12 +2321,17 @@ no_mem:
}

if (flags & F_RSPD_EOP)
- clear_rspq_bufstate(q);
+ clear_rspq_bufstate(q);
}
--budget_left;
}

deliver_partial_bundle(&adap->tdev, q, offload_skbs, ngathered);
+ lro_flush_all(&qs->lro_mgr);
+ qs->port_stats[SGE_PSTAT_LRO_AGGR] = qs->lro_mgr.stats.aggregated;
+ qs->port_stats[SGE_PSTAT_LRO_FLUSHED] = qs->lro_mgr.stats.flushed;
+ qs->port_stats[SGE_PSTAT_LRO_NO_DESC] = qs->lro_mgr.stats.no_desc;
+
if (sleeping)
check_ring_db(adap, qs, sleeping);

@@ -2674,6 +2875,7 @@ int t3_sge_alloc_qset(struct adapter *adapter, unsigned int id, int nports,
{
int i, avail, ret = -ENOMEM;
struct sge_qset *q = &adapter->sge.qs[id];
+ struct net_lro_mgr *lro_mgr = &q->lro_mgr;

init_qset_cntxt(q, id);
init_timer(&q->tx_reclaim_timer);
@@ -2754,6 +2956,10 @@ int t3_sge_alloc_qset(struct adapter *adapter, unsigned int id, int nports,
q->fl[0].order = FL0_PG_ORDER;
q->fl[1].order = FL1_PG_ORDER;

+ q->lro_frag_tbl = kcalloc(MAX_FRAME_SIZE / FL1_PG_CHUNK_SIZE + 1,
+ sizeof(struct skb_frag_struct),
+ GFP_KERNEL);
+ q->lro_nfrags = q->lro_frag_len = 0;
spin_lock_irq(&adapter->sge.reg_lock);

/* FL threshold comparison uses < */
@@ -2803,6 +3009,9 @@ int t3_sge_alloc_qset(struct adapter *adapter, unsigned int id, int nports,
q->adap = adapter;
q->netdev = dev;
t3_update_qset_coalesce(q, p);
+
+ init_lro_mgr(q, lro_mgr);
+
avail = refill_fl(adapter, &q->fl[0], q->fl[0].size,
GFP_KERNEL | __GFP_COMP);
if (!avail) {
diff --git a/drivers/net/cxgb3/t3_cpl.h b/drivers/net/cxgb3/t3_cpl.h
index b7a1a31..a666c5d 100644
--- a/drivers/net/cxgb3/t3_cpl.h
+++ b/drivers/net/cxgb3/t3_cpl.h
@@ -174,6 +174,13 @@ enum { /* TCP congestion control algorithms */
CONG_ALG_HIGHSPEED
};

+enum { /* RSS hash type */
+ RSS_HASH_NONE = 0,
+ RSS_HASH_2_TUPLE = 1,
+ RSS_HASH_4_TUPLE = 2,
+ RSS_HASH_TCPV6 = 3
+};
+
union opcode_tid {
__be32 opcode_tid;
__u8 opcode;
@@ -184,6 +191,10 @@ union opcode_tid {
#define G_OPCODE(x) (((x) >> S_OPCODE) & 0xFF)
#define G_TID(x) ((x) & 0xFFFFFF)

+#define S_HASHTYPE 22
+#define M_HASHTYPE 0x3
+#define G_HASHTYPE(x) (((x) >> S_HASHTYPE) & M_HASHTYPE)
+
/* tid is assumed to be 24-bits */
#define MK_OPCODE_TID(opcode, tid) (V_OPCODE(opcode) | (tid))

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