From 2244d07bfa2097cb00600da91c715a8aa547917e Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Tue, 17 Aug 2010 08:59:14 +0000 Subject: [PATCH] net: simplify flags for tx timestamping This patch removes the abstraction introduced by the union skb_shared_tx in the shared skb data. The access of the different union elements at several places led to some confusion about accessing the shared tx_flags e.g. in skb_orphan_try(). http://marc.info/?l=linux-netdev&m=128084897415886&w=2 Signed-off-by: Oliver Hartkopp Signed-off-by: David S. Miller --- Documentation/networking/timestamping.txt | 22 +++++++++------- drivers/net/bfin_mac.c | 10 +++---- drivers/net/gianfar.c | 15 +++++------ drivers/net/igb/igb.h | 2 +- drivers/net/igb/igb_main.c | 11 ++++---- include/linux/skbuff.h | 44 +++++++++++-------------------- include/net/ip.h | 2 +- include/net/sock.h | 8 ++---- net/can/raw.c | 4 +-- net/core/dev.c | 6 ++--- net/core/skbuff.c | 2 +- net/ipv4/icmp.c | 4 +-- net/ipv4/ip_output.c | 6 ++--- net/ipv4/raw.c | 2 +- net/ipv4/udp.c | 4 +-- net/packet/af_packet.c | 4 +-- net/socket.c | 9 +++---- 17 files changed, 68 insertions(+), 87 deletions(-) diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt index e8c8f4f..98097d8 100644 --- a/Documentation/networking/timestamping.txt +++ b/Documentation/networking/timestamping.txt @@ -172,15 +172,19 @@ struct skb_shared_hwtstamps { }; Time stamps for outgoing packets are to be generated as follows: -- In hard_start_xmit(), check if skb_tx(skb)->hardware is set no-zero. - If yes, then the driver is expected to do hardware time stamping. +- In hard_start_xmit(), check if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) + is set no-zero. If yes, then the driver is expected to do hardware time + stamping. - If this is possible for the skb and requested, then declare - that the driver is doing the time stamping by setting the field - skb_tx(skb)->in_progress non-zero. You might want to keep a pointer - to the associated skb for the next step and not free the skb. A driver - not supporting hardware time stamping doesn't do that. A driver must - never touch sk_buff::tstamp! It is used to store software generated - time stamps by the network subsystem. + that the driver is doing the time stamping by setting the flag + SKBTX_IN_PROGRESS in skb_shinfo(skb)->tx_flags , e.g. with + + skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS; + + You might want to keep a pointer to the associated skb for the next step + and not free the skb. A driver not supporting hardware time stamping doesn't + do that. A driver must never touch sk_buff::tstamp! It is used to store + software generated time stamps by the network subsystem. - As soon as the driver has sent the packet and/or obtained a hardware time stamp for it, it passes the time stamp back by calling skb_hwtstamp_tx() with the original skb, the raw @@ -191,6 +195,6 @@ Time stamps for outgoing packets are to be generated as follows: this would occur at a later time in the processing pipeline than other software time stamping and therefore could lead to unexpected deltas between time stamps. -- If the driver did not call set skb_tx(skb)->in_progress, then +- If the driver did not set the SKBTX_IN_PROGRESS flag (see above), then dev_hard_start_xmit() checks whether software time stamping is wanted as fallback and potentially generates the time stamp. diff --git a/drivers/net/bfin_mac.c b/drivers/net/bfin_mac.c index 012613f..7a0e415 100644 --- a/drivers/net/bfin_mac.c +++ b/drivers/net/bfin_mac.c @@ -803,15 +803,14 @@ static void bfin_dump_hwtamp(char *s, ktime_t *hw, ktime_t *ts, struct timecompa static void bfin_tx_hwtstamp(struct net_device *netdev, struct sk_buff *skb) { struct bfin_mac_local *lp = netdev_priv(netdev); - union skb_shared_tx *shtx = skb_tx(skb); - if (shtx->hardware) { + if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) { int timeout_cnt = MAX_TIMEOUT_CNT; /* When doing time stamping, keep the connection to the socket * a while longer */ - shtx->in_progress = 1; + skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS; /* * The timestamping is done at the EMAC module's MII/RMII interface @@ -991,7 +990,6 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb, struct bfin_mac_local *lp = netdev_priv(dev); u16 *data; u32 data_align = (unsigned long)(skb->data) & 0x3; - union skb_shared_tx *shtx = skb_tx(skb); current_tx_ptr->skb = skb; @@ -1005,7 +1003,7 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb, * of this field are the length of the packet payload in bytes and the higher * 4 bits are the timestamping enable field. */ - if (shtx->hardware) + if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) *data |= 0x1000; current_tx_ptr->desc_a.start_addr = (u32)data; @@ -1015,7 +1013,7 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb, } else { *((u16 *)(current_tx_ptr->packet)) = (u16)(skb->len); /* enable timestamping for the sent packet */ - if (shtx->hardware) + if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) *((u16 *)(current_tx_ptr->packet)) |= 0x1000; memcpy((u8 *)(current_tx_ptr->packet + 2), skb->data, skb->len); diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c index 3d9f958..e6048d6 100644 --- a/drivers/net/gianfar.c +++ b/drivers/net/gianfar.c @@ -2048,7 +2048,6 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) u32 bufaddr; unsigned long flags; unsigned int nr_frags, nr_txbds, length; - union skb_shared_tx *shtx; /* * TOE=1 frames larger than 2500 bytes may see excess delays @@ -2069,10 +2068,10 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) txq = netdev_get_tx_queue(dev, rq); base = tx_queue->tx_bd_base; regs = tx_queue->grp->regs; - shtx = skb_tx(skb); /* check if time stamp should be generated */ - if (unlikely(shtx->hardware && priv->hwts_tx_en)) + if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP && + priv->hwts_tx_en)) do_tstamp = 1; /* make space for additional header when fcb is needed */ @@ -2174,7 +2173,7 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) /* Setup tx hardware time stamping if requested */ if (unlikely(do_tstamp)) { - shtx->in_progress = 1; + skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS; if (fcb == NULL) fcb = gfar_add_fcb(skb); fcb->ptp = 1; @@ -2446,7 +2445,6 @@ static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) int howmany = 0; u32 lstatus; size_t buflen; - union skb_shared_tx *shtx; rx_queue = priv->rx_queue[tx_queue->qindex]; bdp = tx_queue->dirty_tx; @@ -2461,8 +2459,7 @@ static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) * When time stamping, one additional TxBD must be freed. * Also, we need to dma_unmap_single() the TxPAL. */ - shtx = skb_tx(skb); - if (unlikely(shtx->in_progress)) + if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) nr_txbds = frags + 2; else nr_txbds = frags + 1; @@ -2476,7 +2473,7 @@ static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) (lstatus & BD_LENGTH_MASK)) break; - if (unlikely(shtx->in_progress)) { + if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) { next = next_txbd(bdp, base, tx_ring_size); buflen = next->length + GMAC_FCB_LEN; } else @@ -2485,7 +2482,7 @@ static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) dma_unmap_single(&priv->ofdev->dev, bdp->bufPtr, buflen, DMA_TO_DEVICE); - if (unlikely(shtx->in_progress)) { + if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) { struct skb_shared_hwtstamps shhwtstamps; u64 *ns = (u64*) (((u32)skb->data + 0x10) & ~0x7); memset(&shhwtstamps, 0, sizeof(shhwtstamps)); diff --git a/drivers/net/igb/igb.h b/drivers/net/igb/igb.h index 6e63d9a..44e0ff1 100644 --- a/drivers/net/igb/igb.h +++ b/drivers/net/igb/igb.h @@ -143,7 +143,7 @@ struct igb_buffer { u16 next_to_watch; unsigned int bytecount; u16 gso_segs; - union skb_shared_tx shtx; + u8 tx_flags; u8 mapped_as_page; }; /* RX */ diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c index 9b4e589..985e37c 100644 --- a/drivers/net/igb/igb_main.c +++ b/drivers/net/igb/igb_main.c @@ -3954,7 +3954,7 @@ static inline int igb_tx_map_adv(struct igb_ring *tx_ring, struct sk_buff *skb, } tx_ring->buffer_info[i].skb = skb; - tx_ring->buffer_info[i].shtx = skb_shinfo(skb)->tx_flags; + tx_ring->buffer_info[i].tx_flags = skb_shinfo(skb)->tx_flags; /* multiply data chunks by size of headers */ tx_ring->buffer_info[i].bytecount = ((gso_segs - 1) * hlen) + skb->len; tx_ring->buffer_info[i].gso_segs = gso_segs; @@ -4088,7 +4088,6 @@ netdev_tx_t igb_xmit_frame_ring_adv(struct sk_buff *skb, u32 tx_flags = 0; u16 first; u8 hdr_len = 0; - union skb_shared_tx *shtx = skb_tx(skb); /* need: 1 descriptor per page, * + 2 desc gap to keep tail from touching head, @@ -4100,8 +4099,8 @@ netdev_tx_t igb_xmit_frame_ring_adv(struct sk_buff *skb, return NETDEV_TX_BUSY; } - if (unlikely(shtx->hardware)) { - shtx->in_progress = 1; + if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) { + skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS; tx_flags |= IGB_TX_FLAGS_TSTAMP; } @@ -5319,7 +5318,7 @@ static void igb_tx_hwtstamp(struct igb_q_vector *q_vector, struct igb_buffer *bu u64 regval; /* if skb does not support hw timestamp or TX stamp not valid exit */ - if (likely(!buffer_info->shtx.hardware) || + if (likely(!(buffer_info->tx_flags & SKBTX_HW_TSTAMP)) || !(rd32(E1000_TSYNCTXCTL) & E1000_TSYNCTXCTL_VALID)) return; @@ -5500,7 +5499,7 @@ static void igb_rx_hwtstamp(struct igb_q_vector *q_vector, u32 staterr, * values must belong to this one here and therefore we don't need to * compare any of the additional attributes stored for it. * - * If nothing went wrong, then it should have a skb_shared_tx that we + * If nothing went wrong, then it should have a shared tx_flags that we * can turn into a skb_shared_hwtstamps. */ if (staterr & E1000_RXDADV_STAT_TSIP) { diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index d805038..f067c95 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -163,26 +163,19 @@ struct skb_shared_hwtstamps { ktime_t syststamp; }; -/** - * struct skb_shared_tx - instructions for time stamping of outgoing packets - * @hardware: generate hardware time stamp - * @software: generate software time stamp - * @in_progress: device driver is going to provide - * hardware time stamp - * @prevent_sk_orphan: make sk reference available on driver level - * @flags: all shared_tx flags - * - * These flags are attached to packets as part of the - * &skb_shared_info. Use skb_tx() to get a pointer. - */ -union skb_shared_tx { - struct { - __u8 hardware:1, - software:1, - in_progress:1, - prevent_sk_orphan:1; - }; - __u8 flags; +/* Definitions for tx_flags in struct skb_shared_info */ +enum { + /* generate hardware time stamp */ + SKBTX_HW_TSTAMP = 1 << 0, + + /* generate software time stamp */ + SKBTX_SW_TSTAMP = 1 << 1, + + /* device driver is going to provide hardware time stamp */ + SKBTX_IN_PROGRESS = 1 << 2, + + /* ensure the originating sk reference is available on driver level */ + SKBTX_DRV_NEEDS_SK_REF = 1 << 3, }; /* This data is invariant across clones and lives at @@ -195,7 +188,7 @@ struct skb_shared_info { unsigned short gso_segs; unsigned short gso_type; __be32 ip6_frag_id; - union skb_shared_tx tx_flags; + __u8 tx_flags; struct sk_buff *frag_list; struct skb_shared_hwtstamps hwtstamps; @@ -587,11 +580,6 @@ static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb) return &skb_shinfo(skb)->hwtstamps; } -static inline union skb_shared_tx *skb_tx(struct sk_buff *skb) -{ - return &skb_shinfo(skb)->tx_flags; -} - /** * skb_queue_empty - check if a queue is empty * @list: queue head @@ -1996,8 +1984,8 @@ extern void skb_tstamp_tx(struct sk_buff *orig_skb, static inline void sw_tx_timestamp(struct sk_buff *skb) { - union skb_shared_tx *shtx = skb_tx(skb); - if (shtx->software && !shtx->in_progress) + if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP && + !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) skb_tstamp_tx(skb, NULL); } diff --git a/include/net/ip.h b/include/net/ip.h index 890f972..7691aca 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -53,7 +53,7 @@ struct ipcm_cookie { __be32 addr; int oif; struct ip_options *opt; - union skb_shared_tx shtx; + __u8 tx_flags; }; #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) diff --git a/include/net/sock.h b/include/net/sock.h index ac53bfb..100e43b 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1669,17 +1669,13 @@ static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, /** * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped - * @msg: outgoing packet * @sk: socket sending this packet - * @shtx: filled with instructions for time stamping + * @tx_flags: filled with instructions for time stamping * * Currently only depends on SOCK_TIMESTAMPING* flags. Returns error code if * parameters are invalid. */ -extern int sock_tx_timestamp(struct msghdr *msg, - struct sock *sk, - union skb_shared_tx *shtx); - +extern int sock_tx_timestamp(struct sock *sk, __u8 *tx_flags); /** * sk_eat_skb - Release a skb if it is no longer needed diff --git a/net/can/raw.c b/net/can/raw.c index a10e3338..7d77e67 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -647,12 +647,12 @@ static int raw_sendmsg(struct kiocb *iocb, struct socket *sock, err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); if (err < 0) goto free_skb; - err = sock_tx_timestamp(msg, sk, skb_tx(skb)); + err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); if (err < 0) goto free_skb; /* to be able to check the received tx sock reference in raw_rcv() */ - skb_tx(skb)->prevent_sk_orphan = 1; + skb_shinfo(skb)->tx_flags |= SKBTX_DRV_NEEDS_SK_REF; skb->dev = dev; skb->sk = sk; diff --git a/net/core/dev.c b/net/core/dev.c index 586a11c..c1dc8a9 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1902,14 +1902,14 @@ static int dev_gso_segment(struct sk_buff *skb) /* * Try to orphan skb early, right before transmission by the device. - * We cannot orphan skb if tx timestamp is requested, since - * drivers need to call skb_tstamp_tx() to send the timestamp. + * We cannot orphan skb if tx timestamp is requested or the sk-reference + * is needed on driver level for other reasons, e.g. see net/can/raw.c */ static inline void skb_orphan_try(struct sk_buff *skb) { struct sock *sk = skb->sk; - if (sk && !skb_tx(skb)->flags) { + if (sk && !skb_shinfo(skb)->tx_flags) { /* skb_tx_hash() wont be able to get sk. * We copy sk_hash into skb->rxhash */ diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 3a2513f..99ef721 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3016,7 +3016,7 @@ void skb_tstamp_tx(struct sk_buff *orig_skb, } else { /* * no hardware time stamps available, - * so keep the skb_shared_tx and only + * so keep the shared tx_flags and only * store software time stamp */ skb->tstamp = ktime_get_real(); diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index a0d847c7..96bc7f9 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -379,7 +379,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) inet->tos = ip_hdr(skb)->tos; daddr = ipc.addr = rt->rt_src; ipc.opt = NULL; - ipc.shtx.flags = 0; + ipc.tx_flags = 0; if (icmp_param->replyopts.optlen) { ipc.opt = &icmp_param->replyopts; if (ipc.opt->srr) @@ -538,7 +538,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) inet_sk(sk)->tos = tos; ipc.addr = iph->saddr; ipc.opt = &icmp_param.replyopts; - ipc.shtx.flags = 0; + ipc.tx_flags = 0; { struct flowi fl = { diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 04b6989..e807492 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -953,7 +953,7 @@ alloc_new_skb: else /* only the initial fragment is time stamped */ - ipc->shtx.flags = 0; + ipc->tx_flags = 0; } if (skb == NULL) goto error; @@ -964,7 +964,7 @@ alloc_new_skb: skb->ip_summed = csummode; skb->csum = 0; skb_reserve(skb, hh_len); - *skb_tx(skb) = ipc->shtx; + skb_shinfo(skb)->tx_flags = ipc->tx_flags; /* * Find where to start putting bytes. @@ -1384,7 +1384,7 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar daddr = ipc.addr = rt->rt_src; ipc.opt = NULL; - ipc.shtx.flags = 0; + ipc.tx_flags = 0; if (replyopts.opt.optlen) { ipc.opt = &replyopts.opt; diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c index 009a7b2..1f85ef2 100644 --- a/net/ipv4/raw.c +++ b/net/ipv4/raw.c @@ -505,7 +505,7 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, ipc.addr = inet->inet_saddr; ipc.opt = NULL; - ipc.shtx.flags = 0; + ipc.tx_flags = 0; ipc.oif = sk->sk_bound_dev_if; if (msg->msg_controllen) { diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 32e0bef..86e757e 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -797,7 +797,7 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, return -EOPNOTSUPP; ipc.opt = NULL; - ipc.shtx.flags = 0; + ipc.tx_flags = 0; if (up->pending) { /* @@ -845,7 +845,7 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, ipc.addr = inet->inet_saddr; ipc.oif = sk->sk_bound_dev_if; - err = sock_tx_timestamp(msg, sk, &ipc.shtx); + err = sock_tx_timestamp(sk, &ipc.tx_flags); if (err) return err; if (msg->msg_controllen) { diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 9a17f28..3616f27b 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -488,7 +488,7 @@ retry: skb->dev = dev; skb->priority = sk->sk_priority; skb->mark = sk->sk_mark; - err = sock_tx_timestamp(msg, sk, skb_tx(skb)); + err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); if (err < 0) goto out_unlock; @@ -1209,7 +1209,7 @@ static int packet_snd(struct socket *sock, err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len); if (err) goto out_free; - err = sock_tx_timestamp(msg, sk, skb_tx(skb)); + err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); if (err < 0) goto out_free; diff --git a/net/socket.c b/net/socket.c index 2270b94..7848d12 100644 --- a/net/socket.c +++ b/net/socket.c @@ -535,14 +535,13 @@ void sock_release(struct socket *sock) } EXPORT_SYMBOL(sock_release); -int sock_tx_timestamp(struct msghdr *msg, struct sock *sk, - union skb_shared_tx *shtx) +int sock_tx_timestamp(struct sock *sk, __u8 *tx_flags) { - shtx->flags = 0; + *tx_flags = 0; if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE)) - shtx->hardware = 1; + *tx_flags |= SKBTX_HW_TSTAMP; if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE)) - shtx->software = 1; + *tx_flags |= SKBTX_SW_TSTAMP; return 0; } EXPORT_SYMBOL(sock_tx_timestamp); -- 2.7.4