svn commit: r276485 - in head/sys: conf dev/cxgbe modules/cxgbe/if_cxgbe

Luigi Rizzo rizzo at iet.unipi.it
Tue Jan 6 20:05:13 UTC 2015


On Thu, Jan 1, 2015 at 12:19 AM, Navdeep Parhar <np at freebsd.org> wrote:

> Author: np
> Date: Wed Dec 31 23:19:16 2014
> New Revision: 276485
> URL: https://svnweb.freebsd.org/changeset/base/276485
>
> Log:
>   cxgbe(4): major tx rework.
>

​FYI, this commit has some unnamed unions (eg. in t4_mp_ring.c)
which prevent the kernel from compiling with our stock gcc
and its standard kernel build flags (specifically -std=...).

Adding the following in the kernel config

makeoptions COPTFLAGS="-fms-extensions"

seems to do the job

I know it is unavoidable that we'll end up with gcc not working,
​but maybe we can still avoid unnamed unions.

cheers
luigi
​

​


>
>   a) Front load as much work as possible in if_transmit, before any driver
>   lock or software queue has to get involved.
>
>   b) Replace buf_ring with a brand new mp_ring (multiproducer ring).  This
>   is specifically for the tx multiqueue model where one of the if_transmit
>   producer threads becomes the consumer and other producers carry on as
>   usual.  mp_ring is implemented as standalone code and it should be
>   possible to use it in any driver with tx multiqueue.  It also has:
>   - the ability to enqueue/dequeue multiple items.  This might become
>     significant if packet batching is ever implemented.
>   - an abdication mechanism to allow a thread to give up writing tx
>     descriptors and have another if_transmit thread take over.  A thread
>     that's writing tx descriptors can end up doing so for an unbounded
>     time period if a) there are other if_transmit threads continuously
>     feeding the sofware queue, and b) the chip keeps up with whatever the
>     thread is throwing at it.
>   - accurate statistics about interesting events even when the stats come
>     at the expense of additional branches/conditional code.
>
>   The NIC txq lock is uncontested on the fast path at this point.  I've
>   left it there for synchronization with the control events (interface
>   up/down, modload/unload).
>
>   c) Add support for "type 1" coalescing work request in the normal NIC tx
>   path.  This work request is optimized for frames with a single item in
>   the DMA gather list.  These are very common when forwarding packets.
>   Note that netmap tx in cxgbe already uses these "type 1" work requests.
>
>   d) Do not request automatic cidx updates every 32 descriptors.  Instead,
>   request updates via bits in individual work requests (still every 32
>   descriptors approximately).  Also, request an automatic final update
>   when the queue idles after activity.  This means NIC tx reclaim is still
>   performed lazily but it will catch up quickly as soon as the queue
>   idles.  This seems to be the best middle ground and I'll probably do
>   something similar for netmap tx as well.
>
>   e) Implement a faster tx path for WRQs (used by TOE tx and control
>   queues, _not_ by the normal NIC tx).  Allow work requests to be written
>   directly to the hardware descriptor ring if room is available.  I will
>   convert t4_tom and iw_cxgbe modules to this faster style gradually.
>
>   MFC after:    2 months
>
> Added:
>   head/sys/dev/cxgbe/t4_mp_ring.c   (contents, props changed)
>   head/sys/dev/cxgbe/t4_mp_ring.h   (contents, props changed)
> Modified:
>   head/sys/conf/files
>   head/sys/dev/cxgbe/adapter.h
>   head/sys/dev/cxgbe/t4_l2t.c
>   head/sys/dev/cxgbe/t4_main.c
>   head/sys/dev/cxgbe/t4_sge.c
>   head/sys/modules/cxgbe/if_cxgbe/Makefile
>
> Modified: head/sys/conf/files
>
> ==============================================================================
> --- head/sys/conf/files Wed Dec 31 22:52:43 2014        (r276484)
> +++ head/sys/conf/files Wed Dec 31 23:19:16 2014        (r276485)
> @@ -1142,6 +1142,8 @@ dev/cxgb/sys/uipc_mvec.c  optional cxgb p
>         compile-with "${NORMAL_C} -I$S/dev/cxgb"
>  dev/cxgb/cxgb_t3fw.c           optional cxgb cxgb_t3fw \
>         compile-with "${NORMAL_C} -I$S/dev/cxgb"
> +dev/cxgbe/t4_mp_ring.c         optional cxgbe pci \
> +       compile-with "${NORMAL_C} -I$S/dev/cxgbe"
>  dev/cxgbe/t4_main.c            optional cxgbe pci \
>         compile-with "${NORMAL_C} -I$S/dev/cxgbe"
>  dev/cxgbe/t4_netmap.c          optional cxgbe pci \
>
> Modified: head/sys/dev/cxgbe/adapter.h
>
> ==============================================================================
> --- head/sys/dev/cxgbe/adapter.h        Wed Dec 31 22:52:43 2014
> (r276484)
> +++ head/sys/dev/cxgbe/adapter.h        Wed Dec 31 23:19:16 2014
> (r276485)
> @@ -152,7 +152,8 @@ enum {
>         CL_METADATA_SIZE = CACHE_LINE_SIZE,
>
>         SGE_MAX_WR_NDESC = SGE_MAX_WR_LEN / EQ_ESIZE, /* max WR size in
> desc */
> -       TX_SGL_SEGS = 36,
> +       TX_SGL_SEGS = 39,
> +       TX_SGL_SEGS_TSO = 38,
>         TX_WR_FLITS = SGE_MAX_WR_LEN / 8
>  };
>
> @@ -273,6 +274,7 @@ struct port_info {
>         struct timeval last_refreshed;
>         struct port_stats stats;
>         u_int tnl_cong_drops;
> +       u_int tx_parse_error;
>
>         eventhandler_tag vlan_c;
>
> @@ -308,23 +310,9 @@ struct tx_desc {
>         __be64 flit[8];
>  };
>
> -struct tx_map {
> -       struct mbuf *m;
> -       bus_dmamap_t map;
> -};
> -
> -/* DMA maps used for tx */
> -struct tx_maps {
> -       struct tx_map *maps;
> -       uint32_t map_total;     /* # of DMA maps */
> -       uint32_t map_pidx;      /* next map to be used */
> -       uint32_t map_cidx;      /* reclaimed up to this index */
> -       uint32_t map_avail;     /* # of available maps */
> -};
> -
>  struct tx_sdesc {
> +       struct mbuf *m;         /* m_nextpkt linked chain of frames */
>         uint8_t desc_used;      /* # of hardware descriptors used by the
> WR */
> -       uint8_t credits;        /* NIC txq: # of frames sent out in the WR
> */
>  };
>
>
> @@ -378,16 +366,12 @@ struct sge_iq {
>  enum {
>         EQ_CTRL         = 1,
>         EQ_ETH          = 2,
> -#ifdef TCP_OFFLOAD
>         EQ_OFLD         = 3,
> -#endif
>
>         /* eq flags */
> -       EQ_TYPEMASK     = 7,            /* 3 lsbits hold the type */
> -       EQ_ALLOCATED    = (1 << 3),     /* firmware resources allocated */
> -       EQ_DOOMED       = (1 << 4),     /* about to be destroyed */
> -       EQ_CRFLUSHED    = (1 << 5),     /* expecting an update from SGE */
> -       EQ_STALLED      = (1 << 6),     /* out of hw descriptors or
> dmamaps */
> +       EQ_TYPEMASK     = 0x3,          /* 2 lsbits hold the type (see
> above) */
> +       EQ_ALLOCATED    = (1 << 2),     /* firmware resources allocated */
> +       EQ_ENABLED      = (1 << 3),     /* open for business */
>  };
>
>  /* Listed in order of preference.  Update t4_sysctls too if you change
> these */
> @@ -402,32 +386,25 @@ enum {DOORBELL_UDB, DOORBELL_WCWR, DOORB
>  struct sge_eq {
>         unsigned int flags;     /* MUST be first */
>         unsigned int cntxt_id;  /* SGE context id for the eq */
> -       bus_dma_tag_t desc_tag;
> -       bus_dmamap_t desc_map;
> -       char lockname[16];
>         struct mtx eq_lock;
>
>         struct tx_desc *desc;   /* KVA of descriptor ring */
> -       bus_addr_t ba;          /* bus address of descriptor ring */
> -       struct sge_qstat *spg;  /* status page, for convenience */
>         uint16_t doorbells;
>         volatile uint32_t *udb; /* KVA of doorbell (lies within BAR2) */
>         u_int udb_qid;          /* relative qid within the doorbell page */
> -       uint16_t cap;           /* max # of desc, for convenience */
> -       uint16_t avail;         /* available descriptors, for convenience
> */
> -       uint16_t qsize;         /* size (# of entries) of the queue */
> +       uint16_t sidx;          /* index of the entry with the status page
> */
>         uint16_t cidx;          /* consumer idx (desc idx) */
>         uint16_t pidx;          /* producer idx (desc idx) */
> -       uint16_t pending;       /* # of descriptors used since last
> doorbell */
> +       uint16_t equeqidx;      /* EQUEQ last requested at this pidx */
> +       uint16_t dbidx;         /* pidx of the most recent doorbell */
>         uint16_t iqid;          /* iq that gets egr_update for the eq */
>         uint8_t tx_chan;        /* tx channel used by the eq */
> -       struct task tx_task;
> -       struct callout tx_callout;
> +       volatile u_int equiq;   /* EQUIQ outstanding */
>
> -       /* stats */
> -
> -       uint32_t egr_update;    /* # of SGE_EGR_UPDATE notifications for
> eq */
> -       uint32_t unstalled;     /* recovered from stall */
> +       bus_dma_tag_t desc_tag;
> +       bus_dmamap_t desc_map;
> +       bus_addr_t ba;          /* bus address of descriptor ring */
> +       char lockname[16];
>  };
>
>  struct sw_zone_info {
> @@ -499,18 +476,19 @@ struct sge_fl {
>         struct cluster_layout cll_alt;  /* alternate refill zone, layout */
>  };
>
> +struct mp_ring;
> +
>  /* txq: SGE egress queue + what's needed for Ethernet NIC */
>  struct sge_txq {
>         struct sge_eq eq;       /* MUST be first */
>
>         struct ifnet *ifp;      /* the interface this txq belongs to */
> -       bus_dma_tag_t tx_tag;   /* tag for transmit buffers */
> -       struct buf_ring *br;    /* tx buffer ring */
> +       struct mp_ring *r;      /* tx software ring */
>         struct tx_sdesc *sdesc; /* KVA of software descriptor ring */
> -       struct mbuf *m;         /* held up due to temporary resource
> shortage */
> -
> -       struct tx_maps txmaps;
> +       struct sglist *gl;
> +       __be32 cpl_ctrl0;       /* for convenience */
>
> +       struct task tx_reclaim_task;
>         /* stats for common events first */
>
>         uint64_t txcsum;        /* # of times hardware assisted with
> checksum */
> @@ -519,13 +497,12 @@ struct sge_txq {
>         uint64_t imm_wrs;       /* # of work requests with immediate data
> */
>         uint64_t sgl_wrs;       /* # of work requests with direct SGL */
>         uint64_t txpkt_wrs;     /* # of txpkt work requests (not
> coalesced) */
> -       uint64_t txpkts_wrs;    /* # of coalesced tx work requests */
> -       uint64_t txpkts_pkts;   /* # of frames in coalesced tx work
> requests */
> +       uint64_t txpkts0_wrs;   /* # of type0 coalesced tx work requests */
> +       uint64_t txpkts1_wrs;   /* # of type1 coalesced tx work requests */
> +       uint64_t txpkts0_pkts;  /* # of frames in type0 coalesced tx WRs */
> +       uint64_t txpkts1_pkts;  /* # of frames in type1 coalesced tx WRs */
>
>         /* stats for not-that-common events */
> -
> -       uint32_t no_dmamap;     /* no DMA map to load the mbuf */
> -       uint32_t no_desc;       /* out of hardware descriptors */
>  } __aligned(CACHE_LINE_SIZE);
>
>  /* rxq: SGE ingress queue + SGE free list + miscellaneous items */
> @@ -574,7 +551,13 @@ struct wrqe {
>         STAILQ_ENTRY(wrqe) link;
>         struct sge_wrq *wrq;
>         int wr_len;
> -       uint64_t wr[] __aligned(16);
> +       char wr[] __aligned(16);
> +};
> +
> +struct wrq_cookie {
> +       TAILQ_ENTRY(wrq_cookie) link;
> +       int ndesc;
> +       int pidx;
>  };
>
>  /*
> @@ -585,17 +568,32 @@ struct sge_wrq {
>         struct sge_eq eq;       /* MUST be first */
>
>         struct adapter *adapter;
> +       struct task wrq_tx_task;
> +
> +       /* Tx desc reserved but WR not "committed" yet. */
> +       TAILQ_HEAD(wrq_incomplete_wrs , wrq_cookie) incomplete_wrs;
>
> -       /* List of WRs held up due to lack of tx descriptors */
> +       /* List of WRs ready to go out as soon as descriptors are
> available. */
>         STAILQ_HEAD(, wrqe) wr_list;
> +       u_int nwr_pending;
> +       u_int ndesc_needed;
>
>         /* stats for common events first */
>
> -       uint64_t tx_wrs;        /* # of tx work requests */
> +       uint64_t tx_wrs_direct; /* # of WRs written directly to desc ring.
> */
> +       uint64_t tx_wrs_ss;     /* # of WRs copied from scratch space. */
> +       uint64_t tx_wrs_copied; /* # of WRs queued and copied to desc
> ring. */
>
>         /* stats for not-that-common events */
>
> -       uint32_t no_desc;       /* out of hardware descriptors */
> +       /*
> +        * Scratch space for work requests that wrap around after reaching
> the
> +        * status page, and some infomation about the last WR that used it.
> +        */
> +       uint16_t ss_pidx;
> +       uint16_t ss_len;
> +       uint8_t ss[SGE_MAX_WR_LEN];
> +
>  } __aligned(CACHE_LINE_SIZE);
>
>
> @@ -744,7 +742,7 @@ struct adapter {
>         struct sge sge;
>         int lro_timeout;
>
> -       struct taskqueue *tq[NCHAN];    /* taskqueues that flush data out
> */
> +       struct taskqueue *tq[NCHAN];    /* General purpose taskqueues */
>         struct port_info *port[MAX_NPORTS];
>         uint8_t chan_map[NCHAN];
>
> @@ -978,12 +976,11 @@ static inline int
>  tx_resume_threshold(struct sge_eq *eq)
>  {
>
> -       return (eq->qsize / 4);
> +       /* not quite the same as qsize / 4, but this will do. */
> +       return (eq->sidx / 4);
>  }
>
>  /* t4_main.c */
> -void t4_tx_task(void *, int);
> -void t4_tx_callout(void *);
>  int t4_os_find_pci_capability(struct adapter *, int);
>  int t4_os_pci_save_state(struct adapter *);
>  int t4_os_pci_restore_state(struct adapter *);
> @@ -1024,16 +1021,15 @@ int t4_setup_adapter_queues(struct adapt
>  int t4_teardown_adapter_queues(struct adapter *);
>  int t4_setup_port_queues(struct port_info *);
>  int t4_teardown_port_queues(struct port_info *);
> -int t4_alloc_tx_maps(struct tx_maps *, bus_dma_tag_t, int, int);
> -void t4_free_tx_maps(struct tx_maps *, bus_dma_tag_t);
>  void t4_intr_all(void *);
>  void t4_intr(void *);
>  void t4_intr_err(void *);
>  void t4_intr_evt(void *);
>  void t4_wrq_tx_locked(struct adapter *, struct sge_wrq *, struct wrqe *);
> -int t4_eth_tx(struct ifnet *, struct sge_txq *, struct mbuf *);
>  void t4_update_fl_bufsize(struct ifnet *);
> -int can_resume_tx(struct sge_eq *);
> +int parse_pkt(struct mbuf **);
> +void *start_wrq_wr(struct sge_wrq *, int, struct wrq_cookie *);
> +void commit_wrq_wr(struct sge_wrq *, void *, struct wrq_cookie *);
>
>  /* t4_tracer.c */
>  struct t4_tracer;
>
> Modified: head/sys/dev/cxgbe/t4_l2t.c
>
> ==============================================================================
> --- head/sys/dev/cxgbe/t4_l2t.c Wed Dec 31 22:52:43 2014        (r276484)
> +++ head/sys/dev/cxgbe/t4_l2t.c Wed Dec 31 23:19:16 2014        (r276485)
> @@ -113,16 +113,15 @@ found:
>  int
>  t4_write_l2e(struct adapter *sc, struct l2t_entry *e, int sync)
>  {
> -       struct wrqe *wr;
> +       struct wrq_cookie cookie;
>         struct cpl_l2t_write_req *req;
>         int idx = e->idx + sc->vres.l2t.start;
>
>         mtx_assert(&e->lock, MA_OWNED);
>
> -       wr = alloc_wrqe(sizeof(*req), &sc->sge.mgmtq);
> -       if (wr == NULL)
> +       req = start_wrq_wr(&sc->sge.mgmtq, howmany(sizeof(*req), 16),
> &cookie);
> +       if (req == NULL)
>                 return (ENOMEM);
> -       req = wrtod(wr);
>
>         INIT_TP_WR(req, 0);
>         OPCODE_TID(req) = htonl(MK_OPCODE_TID(CPL_L2T_WRITE_REQ, idx |
> @@ -132,7 +131,7 @@ t4_write_l2e(struct adapter *sc, struct
>         req->vlan = htons(e->vlan);
>         memcpy(req->dst_mac, e->dmac, sizeof(req->dst_mac));
>
> -       t4_wrq_tx(sc, wr);
> +       commit_wrq_wr(&sc->sge.mgmtq, req, &cookie);
>
>         if (sync && e->state != L2T_STATE_SWITCHING)
>                 e->state = L2T_STATE_SYNC_WRITE;
>
> Modified: head/sys/dev/cxgbe/t4_main.c
>
> ==============================================================================
> --- head/sys/dev/cxgbe/t4_main.c        Wed Dec 31 22:52:43 2014
> (r276484)
> +++ head/sys/dev/cxgbe/t4_main.c        Wed Dec 31 23:19:16 2014
> (r276485)
> @@ -66,6 +66,7 @@ __FBSDID("$FreeBSD$");
>  #include "common/t4_regs_values.h"
>  #include "t4_ioctl.h"
>  #include "t4_l2t.h"
> +#include "t4_mp_ring.h"
>
>  /* T4 bus driver interface */
>  static int t4_probe(device_t);
> @@ -378,7 +379,8 @@ static void build_medialist(struct port_
>  static int cxgbe_init_synchronized(struct port_info *);
>  static int cxgbe_uninit_synchronized(struct port_info *);
>  static int setup_intr_handlers(struct adapter *);
> -static void quiesce_eq(struct adapter *, struct sge_eq *);
> +static void quiesce_txq(struct adapter *, struct sge_txq *);
> +static void quiesce_wrq(struct adapter *, struct sge_wrq *);
>  static void quiesce_iq(struct adapter *, struct sge_iq *);
>  static void quiesce_fl(struct adapter *, struct sge_fl *);
>  static int t4_alloc_irq(struct adapter *, struct irq *, int rid,
> @@ -434,7 +436,6 @@ static int sysctl_tx_rate(SYSCTL_HANDLER
>  static int sysctl_ulprx_la(SYSCTL_HANDLER_ARGS);
>  static int sysctl_wcwr_stats(SYSCTL_HANDLER_ARGS);
>  #endif
> -static inline void txq_start(struct ifnet *, struct sge_txq *);
>  static uint32_t fconf_to_mode(uint32_t);
>  static uint32_t mode_to_fconf(uint32_t);
>  static uint32_t fspec_to_fconf(struct t4_filter_specification *);
> @@ -1429,67 +1430,36 @@ cxgbe_transmit(struct ifnet *ifp, struct
>  {
>         struct port_info *pi = ifp->if_softc;
>         struct adapter *sc = pi->adapter;
> -       struct sge_txq *txq = &sc->sge.txq[pi->first_txq];
> -       struct buf_ring *br;
> +       struct sge_txq *txq;
> +       void *items[1];
>         int rc;
>
>         M_ASSERTPKTHDR(m);
> +       MPASS(m->m_nextpkt == NULL);    /* not quite ready for this yet */
>
>         if (__predict_false(pi->link_cfg.link_ok == 0)) {
>                 m_freem(m);
>                 return (ENETDOWN);
>         }
>
> -       /* check if flowid is set */
> -       if (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE)
> -               txq += ((m->m_pkthdr.flowid % (pi->ntxq -
> pi->rsrv_noflowq))
> -                   + pi->rsrv_noflowq);
> -       br = txq->br;
> -
> -       if (TXQ_TRYLOCK(txq) == 0) {
> -               struct sge_eq *eq = &txq->eq;
> -
> -               /*
> -                * It is possible that t4_eth_tx finishes up and releases
> the
> -                * lock between the TRYLOCK above and the drbr_enqueue
> here.  We
> -                * need to make sure that this mbuf doesn't just sit there
> in
> -                * the drbr.
> -                */
> -
> -               rc = drbr_enqueue(ifp, br, m);
> -               if (rc == 0 && callout_pending(&eq->tx_callout) == 0 &&
> -                   !(eq->flags & EQ_DOOMED))
> -                       callout_reset(&eq->tx_callout, 1, t4_tx_callout,
> eq);
> +       rc = parse_pkt(&m);
> +       if (__predict_false(rc != 0)) {
> +               MPASS(m == NULL);                       /* was freed
> already */
> +               atomic_add_int(&pi->tx_parse_error, 1); /* rare, atomic is
> ok */
>                 return (rc);
>         }
>
> -       /*
> -        * txq->m is the mbuf that is held up due to a temporary shortage
> of
> -        * resources and it should be put on the wire first.  Then what's
> in
> -        * drbr and finally the mbuf that was just passed in to us.
> -        *
> -        * Return code should indicate the fate of the mbuf that was
> passed in
> -        * this time.
> -        */
> -
> -       TXQ_LOCK_ASSERT_OWNED(txq);
> -       if (drbr_needs_enqueue(ifp, br) || txq->m) {
> -
> -               /* Queued for transmission. */
> -
> -               rc = drbr_enqueue(ifp, br, m);
> -               m = txq->m ? txq->m : drbr_dequeue(ifp, br);
> -               (void) t4_eth_tx(ifp, txq, m);
> -               TXQ_UNLOCK(txq);
> -               return (rc);
> -       }
> +       /* Select a txq. */
> +       txq = &sc->sge.txq[pi->first_txq];
> +       if (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE)
> +               txq += ((m->m_pkthdr.flowid % (pi->ntxq -
> pi->rsrv_noflowq)) +
> +                   pi->rsrv_noflowq);
>
> -       /* Direct transmission. */
> -       rc = t4_eth_tx(ifp, txq, m);
> -       if (rc != 0 && txq->m)
> -               rc = 0; /* held, will be transmitted soon (hopefully) */
> +       items[0] = m;
> +       rc = mp_ring_enqueue(txq->r, items, 1, 4096);
> +       if (__predict_false(rc != 0))
> +               m_freem(m);
>
> -       TXQ_UNLOCK(txq);
>         return (rc);
>  }
>
> @@ -1499,17 +1469,17 @@ cxgbe_qflush(struct ifnet *ifp)
>         struct port_info *pi = ifp->if_softc;
>         struct sge_txq *txq;
>         int i;
> -       struct mbuf *m;
>
>         /* queues do not exist if !PORT_INIT_DONE. */
>         if (pi->flags & PORT_INIT_DONE) {
>                 for_each_txq(pi, i, txq) {
>                         TXQ_LOCK(txq);
> -                       m_freem(txq->m);
> -                       txq->m = NULL;
> -                       while ((m = buf_ring_dequeue_sc(txq->br)) != NULL)
> -                               m_freem(m);
> +                       txq->eq.flags &= ~EQ_ENABLED;
>                         TXQ_UNLOCK(txq);
> +                       while (!mp_ring_is_idle(txq->r)) {
> +                               mp_ring_check_drainage(txq->r, 0);
> +                               pause("qflush", 1);
> +                       }
>                 }
>         }
>         if_qflush(ifp);
> @@ -1564,7 +1534,7 @@ cxgbe_get_counter(struct ifnet *ifp, ift
>                         struct sge_txq *txq;
>
>                         for_each_txq(pi, i, txq)
> -                               drops += txq->br->br_drops;
> +                               drops += counter_u64_fetch(txq->r->drops);
>                 }
>
>                 return (drops);
> @@ -3236,7 +3206,8 @@ cxgbe_init_synchronized(struct port_info
>  {
>         struct adapter *sc = pi->adapter;
>         struct ifnet *ifp = pi->ifp;
> -       int rc = 0;
> +       int rc = 0, i;
> +       struct sge_txq *txq;
>
>         ASSERT_SYNCHRONIZED_OP(sc);
>
> @@ -3265,6 +3236,17 @@ cxgbe_init_synchronized(struct port_info
>         }
>
>         /*
> +        * Can't fail from this point onwards.  Review
> cxgbe_uninit_synchronized
> +        * if this changes.
> +        */
> +
> +       for_each_txq(pi, i, txq) {
> +               TXQ_LOCK(txq);
> +               txq->eq.flags |= EQ_ENABLED;
> +               TXQ_UNLOCK(txq);
> +       }
> +
> +       /*
>          * The first iq of the first port to come up is used for tracing.
>          */
>         if (sc->traceq < 0) {
> @@ -3297,7 +3279,8 @@ cxgbe_uninit_synchronized(struct port_in
>  {
>         struct adapter *sc = pi->adapter;
>         struct ifnet *ifp = pi->ifp;
> -       int rc;
> +       int rc, i;
> +       struct sge_txq *txq;
>
>         ASSERT_SYNCHRONIZED_OP(sc);
>
> @@ -3314,6 +3297,12 @@ cxgbe_uninit_synchronized(struct port_in
>                 return (rc);
>         }
>
> +       for_each_txq(pi, i, txq) {
> +               TXQ_LOCK(txq);
> +               txq->eq.flags &= ~EQ_ENABLED;
> +               TXQ_UNLOCK(txq);
> +       }
> +
>         clrbit(&sc->open_device_map, pi->port_id);
>         PORT_LOCK(pi);
>         ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
> @@ -3543,15 +3532,17 @@ port_full_uninit(struct port_info *pi)
>
>         if (pi->flags & PORT_INIT_DONE) {
>
> -               /* Need to quiesce queues.  XXX: ctrl queues? */
> +               /* Need to quiesce queues.  */
> +
> +               quiesce_wrq(sc, &sc->sge.ctrlq[pi->port_id]);
>
>                 for_each_txq(pi, i, txq) {
> -                       quiesce_eq(sc, &txq->eq);
> +                       quiesce_txq(sc, txq);
>                 }
>
>  #ifdef TCP_OFFLOAD
>                 for_each_ofld_txq(pi, i, ofld_txq) {
> -                       quiesce_eq(sc, &ofld_txq->eq);
> +                       quiesce_wrq(sc, ofld_txq);
>                 }
>  #endif
>
> @@ -3576,23 +3567,39 @@ port_full_uninit(struct port_info *pi)
>  }
>
>  static void
> -quiesce_eq(struct adapter *sc, struct sge_eq *eq)
> +quiesce_txq(struct adapter *sc, struct sge_txq *txq)
>  {
> -       EQ_LOCK(eq);
> -       eq->flags |= EQ_DOOMED;
> +       struct sge_eq *eq = &txq->eq;
> +       struct sge_qstat *spg = (void *)&eq->desc[eq->sidx];
>
> -       /*
> -        * Wait for the response to a credit flush if one's
> -        * pending.
> -        */
> -       while (eq->flags & EQ_CRFLUSHED)
> -               mtx_sleep(eq, &eq->eq_lock, 0, "crflush", 0);
> -       EQ_UNLOCK(eq);
> +       (void) sc;      /* unused */
>
> -       callout_drain(&eq->tx_callout); /* XXX: iffy */
> -       pause("callout", 10);           /* Still iffy */
> +#ifdef INVARIANTS
> +       TXQ_LOCK(txq);
> +       MPASS((eq->flags & EQ_ENABLED) == 0);
> +       TXQ_UNLOCK(txq);
> +#endif
>
> -       taskqueue_drain(sc->tq[eq->tx_chan], &eq->tx_task);
> +       /* Wait for the mp_ring to empty. */
> +       while (!mp_ring_is_idle(txq->r)) {
> +               mp_ring_check_drainage(txq->r, 0);
> +               pause("rquiesce", 1);
> +       }
> +
> +       /* Then wait for the hardware to finish. */
> +       while (spg->cidx != htobe16(eq->pidx))
> +               pause("equiesce", 1);
> +
> +       /* Finally, wait for the driver to reclaim all descriptors. */
> +       while (eq->cidx != eq->pidx)
> +               pause("dquiesce", 1);
> +}
> +
> +static void
> +quiesce_wrq(struct adapter *sc, struct sge_wrq *wrq)
> +{
> +
> +       /* XXXTX */
>  }
>
>  static void
> @@ -4892,6 +4899,9 @@ cxgbe_sysctls(struct port_info *pi)
>         oid = SYSCTL_ADD_NODE(ctx, children, OID_AUTO, "stats", CTLFLAG_RD,
>             NULL, "port statistics");
>         children = SYSCTL_CHILDREN(oid);
> +       SYSCTL_ADD_UINT(ctx, children, OID_AUTO, "tx_parse_error",
> CTLFLAG_RD,
> +           &pi->tx_parse_error, 0,
> +           "# of tx packets with invalid length or # of segments");
>
>  #define SYSCTL_ADD_T4_REG64(pi, name, desc, reg) \
>         SYSCTL_ADD_OID(ctx, children, OID_AUTO, name, \
> @@ -6947,74 +6957,6 @@ sysctl_wcwr_stats(SYSCTL_HANDLER_ARGS)
>  }
>  #endif
>
> -static inline void
> -txq_start(struct ifnet *ifp, struct sge_txq *txq)
> -{
> -       struct buf_ring *br;
> -       struct mbuf *m;
> -
> -       TXQ_LOCK_ASSERT_OWNED(txq);
> -
> -       br = txq->br;
> -       m = txq->m ? txq->m : drbr_dequeue(ifp, br);
> -       if (m)
> -               t4_eth_tx(ifp, txq, m);
> -}
> -
> -void
> -t4_tx_callout(void *arg)
> -{
> -       struct sge_eq *eq = arg;
> -       struct adapter *sc;
> -
> -       if (EQ_TRYLOCK(eq) == 0)
> -               goto reschedule;
> -
> -       if (eq->flags & EQ_STALLED && !can_resume_tx(eq)) {
> -               EQ_UNLOCK(eq);
> -reschedule:
> -               if (__predict_true(!(eq->flags && EQ_DOOMED)))
> -                       callout_schedule(&eq->tx_callout, 1);
> -               return;
> -       }
> -
> -       EQ_LOCK_ASSERT_OWNED(eq);
> -
> -       if (__predict_true((eq->flags & EQ_DOOMED) == 0)) {
> -
> -               if ((eq->flags & EQ_TYPEMASK) == EQ_ETH) {
> -                       struct sge_txq *txq = arg;
> -                       struct port_info *pi = txq->ifp->if_softc;
> -
> -                       sc = pi->adapter;
> -               } else {
> -                       struct sge_wrq *wrq = arg;
> -
> -                       sc = wrq->adapter;
> -               }
> -
> -               taskqueue_enqueue(sc->tq[eq->tx_chan], &eq->tx_task);
> -       }
> -
> -       EQ_UNLOCK(eq);
> -}
> -
> -void
> -t4_tx_task(void *arg, int count)
> -{
> -       struct sge_eq *eq = arg;
> -
> -       EQ_LOCK(eq);
> -       if ((eq->flags & EQ_TYPEMASK) == EQ_ETH) {
> -               struct sge_txq *txq = arg;
> -               txq_start(txq->ifp, txq);
> -       } else {
> -               struct sge_wrq *wrq = arg;
> -               t4_wrq_tx_locked(wrq->adapter, wrq, NULL);
> -       }
> -       EQ_UNLOCK(eq);
> -}
> -
>  static uint32_t
>  fconf_to_mode(uint32_t fconf)
>  {
> @@ -7452,9 +7394,9 @@ static int
>  set_filter_wr(struct adapter *sc, int fidx)
>  {
>         struct filter_entry *f = &sc->tids.ftid_tab[fidx];
> -       struct wrqe *wr;
>         struct fw_filter_wr *fwr;
>         unsigned int ftid;
> +       struct wrq_cookie cookie;
>
>         ASSERT_SYNCHRONIZED_OP(sc);
>
> @@ -7473,12 +7415,10 @@ set_filter_wr(struct adapter *sc, int fi
>
>         ftid = sc->tids.ftid_base + fidx;
>
> -       wr = alloc_wrqe(sizeof(*fwr), &sc->sge.mgmtq);
> -       if (wr == NULL)
> +       fwr = start_wrq_wr(&sc->sge.mgmtq, howmany(sizeof(*fwr), 16),
> &cookie);
> +       if (fwr == NULL)
>                 return (ENOMEM);
> -
> -       fwr = wrtod(wr);
> -       bzero(fwr, sizeof (*fwr));
> +       bzero(fwr, sizeof(*fwr));
>
>         fwr->op_pkd = htobe32(V_FW_WR_OP(FW_FILTER_WR));
>         fwr->len16_pkd = htobe32(FW_LEN16(*fwr));
> @@ -7547,7 +7487,7 @@ set_filter_wr(struct adapter *sc, int fi
>         f->pending = 1;
>         sc->tids.ftids_in_use++;
>
> -       t4_wrq_tx(sc, wr);
> +       commit_wrq_wr(&sc->sge.mgmtq, fwr, &cookie);
>         return (0);
>  }
>
> @@ -7555,22 +7495,21 @@ static int
>  del_filter_wr(struct adapter *sc, int fidx)
>  {
>         struct filter_entry *f = &sc->tids.ftid_tab[fidx];
> -       struct wrqe *wr;
>         struct fw_filter_wr *fwr;
>         unsigned int ftid;
> +       struct wrq_cookie cookie;
>
>         ftid = sc->tids.ftid_base + fidx;
>
> -       wr = alloc_wrqe(sizeof(*fwr), &sc->sge.mgmtq);
> -       if (wr == NULL)
> +       fwr = start_wrq_wr(&sc->sge.mgmtq, howmany(sizeof(*fwr), 16),
> &cookie);
> +       if (fwr == NULL)
>                 return (ENOMEM);
> -       fwr = wrtod(wr);
>         bzero(fwr, sizeof (*fwr));
>
>         t4_mk_filtdelwr(ftid, fwr, sc->sge.fwq.abs_id);
>
>         f->pending = 1;
> -       t4_wrq_tx(sc, wr);
> +       commit_wrq_wr(&sc->sge.mgmtq, fwr, &cookie);
>         return (0);
>  }
>
> @@ -8170,6 +8109,7 @@ t4_ioctl(struct cdev *dev, unsigned long
>
>                 /* MAC stats */
>                 t4_clr_port_stats(sc, pi->tx_chan);
> +               pi->tx_parse_error = 0;
>
>                 if (pi->flags & PORT_INIT_DONE) {
>                         struct sge_rxq *rxq;
> @@ -8192,24 +8132,24 @@ t4_ioctl(struct cdev *dev, unsigned long
>                                 txq->imm_wrs = 0;
>                                 txq->sgl_wrs = 0;
>                                 txq->txpkt_wrs = 0;
> -                               txq->txpkts_wrs = 0;
> -                               txq->txpkts_pkts = 0;
> -                               txq->br->br_drops = 0;
> -                               txq->no_dmamap = 0;
> -                               txq->no_desc = 0;
> +                               txq->txpkts0_wrs = 0;
> +                               txq->txpkts1_wrs = 0;
> +                               txq->txpkts0_pkts = 0;
> +                               txq->txpkts1_pkts = 0;
> +                               mp_ring_reset_stats(txq->r);
>                         }
>
>  #ifdef TCP_OFFLOAD
>                         /* nothing to clear for each ofld_rxq */
>
>                         for_each_ofld_txq(pi, i, wrq) {
> -                               wrq->tx_wrs = 0;
> -                               wrq->no_desc = 0;
> +                               wrq->tx_wrs_direct = 0;
> +                               wrq->tx_wrs_copied = 0;
>                         }
>  #endif
>                         wrq = &sc->sge.ctrlq[pi->port_id];
> -                       wrq->tx_wrs = 0;
> -                       wrq->no_desc = 0;
> +                       wrq->tx_wrs_direct = 0;
> +                       wrq->tx_wrs_copied = 0;
>                 }
>                 break;
>         }
>
> Added: head/sys/dev/cxgbe/t4_mp_ring.c
>
> ==============================================================================
> --- /dev/null   00:00:00 1970   (empty, because file is newly added)
> +++ head/sys/dev/cxgbe/t4_mp_ring.c     Wed Dec 31 23:19:16 2014
> (r276485)
> @@ -0,0 +1,364 @@
> +/*-
> + * Copyright (c) 2014 Chelsio Communications, Inc.
> + * All rights reserved.
> + * Written by: Navdeep Parhar <np at FreeBSD.org>
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
> PURPOSE
> + * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
> STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
> WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + */
> +
> +#include <sys/cdefs.h>
> +__FBSDID("$FreeBSD$");
> +
> +#include <sys/types.h>
> +#include <sys/param.h>
> +#include <sys/systm.h>
> +#include <sys/counter.h>
> +#include <sys/lock.h>
> +#include <sys/malloc.h>
> +#include <machine/cpu.h>
> +
> +#include "t4_mp_ring.h"
> +
> +union ring_state {
> +       struct {
> +               uint16_t pidx_head;
> +               uint16_t pidx_tail;
> +               uint16_t cidx;
> +               uint16_t flags;
> +       };
> +       uint64_t state;
> +};
> +
> +enum {
> +       IDLE = 0,       /* consumer ran to completion, nothing more to do.
> */
> +       BUSY,           /* consumer is running already, or will be
> shortly. */
> +       STALLED,        /* consumer stopped due to lack of resources. */
> +       ABDICATED,      /* consumer stopped even though there was work to
> be
> +                          done because it wants another thread to take
> over. */
> +};
> +
> +static inline uint16_t
> +space_available(struct mp_ring *r, union ring_state s)
> +{
> +       uint16_t x = r->size - 1;
> +
> +       if (s.cidx == s.pidx_head)
> +               return (x);
> +       else if (s.cidx > s.pidx_head)
> +               return (s.cidx - s.pidx_head - 1);
> +       else
> +               return (x - s.pidx_head + s.cidx);
> +}
> +
> +static inline uint16_t
> +increment_idx(struct mp_ring *r, uint16_t idx, uint16_t n)
> +{
> +       int x = r->size - idx;
> +
> +       MPASS(x > 0);
> +       return (x > n ? idx + n : n - x);
> +}
> +
> +/* Consumer is about to update the ring's state to s */
> +static inline uint16_t
> +state_to_flags(union ring_state s, int abdicate)
> +{
> +
> +       if (s.cidx == s.pidx_tail)
> +               return (IDLE);
> +       else if (abdicate && s.pidx_tail != s.pidx_head)
> +               return (ABDICATED);
> +
> +       return (BUSY);
> +}
> +
> +/*
> + * Caller passes in a state, with a guarantee that there is work to do
> and that
> + * all items up to the pidx_tail in the state are visible.
> + */
> +static void
> +drain_ring(struct mp_ring *r, union ring_state os, uint16_t prev, int
> budget)
> +{
> +       union ring_state ns;
> +       int n, pending, total;
> +       uint16_t cidx = os.cidx;
> +       uint16_t pidx = os.pidx_tail;
> +
> +       MPASS(os.flags == BUSY);
> +       MPASS(cidx != pidx);
> +
> +       if (prev == IDLE)
> +               counter_u64_add(r->starts, 1);
> +       pending = 0;
> +       total = 0;
> +
> +       while (cidx != pidx) {
> +
> +               /* Items from cidx to pidx are available for consumption.
> */
> +               n = r->drain(r, cidx, pidx);
> +               if (n == 0) {
> +                       critical_enter();
> +                       do {
> +                               os.state = ns.state = r->state;
> +                               ns.cidx = cidx;
> +                               ns.flags = STALLED;
> +                       } while (atomic_cmpset_64(&r->state, os.state,
> +                           ns.state) == 0);
> +                       critical_exit();
> +                       if (prev != STALLED)
> +                               counter_u64_add(r->stalls, 1);
> +                       else if (total > 0) {
> +                               counter_u64_add(r->restarts, 1);
> +                               counter_u64_add(r->stalls, 1);
> +                       }
> +                       break;
> +               }
> +               cidx = increment_idx(r, cidx, n);
> +               pending += n;
> +               total += n;
> +
> +               /*
> +                * We update the cidx only if we've caught up with the
> pidx, the
> +                * real cidx is getting too far ahead of the one visible to
> +                * everyone else, or we have exceeded our budget.
> +                */
> +               if (cidx != pidx && pending < 64 && total < budget)
> +                       continue;
> +               critical_enter();
> +               do {
> +                       os.state = ns.state = r->state;
> +                       ns.cidx = cidx;
> +                       ns.flags = state_to_flags(ns, total >= budget);
> +               } while (atomic_cmpset_acq_64(&r->state, os.state,
> ns.state) == 0);
> +               critical_exit();
> +
> +               if (ns.flags == ABDICATED)
> +                       counter_u64_add(r->abdications, 1);
> +               if (ns.flags != BUSY) {
> +                       /* Wrong loop exit if we're going to stall. */
> +                       MPASS(ns.flags != STALLED);
> +                       if (prev == STALLED) {
> +                               MPASS(total > 0);
> +                               counter_u64_add(r->restarts, 1);
> +                       }
> +                       break;
> +               }
> +
> +               /*
> +                * The acquire style atomic above guarantees visibility of
> items
> +                * associated with any pidx change that we notice here.
> +                */
> +               pidx = ns.pidx_tail;
> +               pending = 0;
> +       }
> +}
> +
> +int
> +mp_ring_alloc(struct mp_ring **pr, int size, void *cookie, ring_drain_t
> drain,
> +    ring_can_drain_t can_drain, struct malloc_type *mt, int flags)
> +{
> +       struct mp_ring *r;
> +
> +       /* All idx are 16b so size can be 65536 at most */
> +       if (pr == NULL || size < 2 || size > 65536 || drain == NULL ||
> +           can_drain == NULL)
> +               return (EINVAL);
> +       *pr = NULL;
> +       flags &= M_NOWAIT | M_WAITOK;
> +       MPASS(flags != 0);
> +
> +       r = malloc(__offsetof(struct mp_ring, items[size]), mt, flags |
> M_ZERO);
> +       if (r == NULL)
> +               return (ENOMEM);
> +       r->size = size;
> +       r->cookie = cookie;
> +       r->mt = mt;
> +       r->drain = drain;
> +       r->can_drain = can_drain;
> +       r->enqueues = counter_u64_alloc(flags);
> +       r->drops = counter_u64_alloc(flags);
> +       r->starts = counter_u64_alloc(flags);
> +       r->stalls = counter_u64_alloc(flags);
> +       r->restarts = counter_u64_alloc(flags);
> +       r->abdications = counter_u64_alloc(flags);
> +       if (r->enqueues == NULL || r->drops == NULL || r->starts == NULL ||
> +           r->stalls == NULL || r->restarts == NULL ||
> +           r->abdications == NULL) {
> +               mp_ring_free(r);
> +               return (ENOMEM);
> +       }
> +
> +       *pr = r;
> +       return (0);
> +}
> +
> +void
> +
> +mp_ring_free(struct mp_ring *r)
> +{
> +
> +       if (r == NULL)
> +               return;
> +
> +       if (r->enqueues != NULL)
> +               counter_u64_free(r->enqueues);
> +       if (r->drops != NULL)
> +               counter_u64_free(r->drops);
> +       if (r->starts != NULL)
> +               counter_u64_free(r->starts);
> +       if (r->stalls != NULL)
> +               counter_u64_free(r->stalls);
> +       if (r->restarts != NULL)
> +               counter_u64_free(r->restarts);
> +       if (r->abdications != NULL)
> +               counter_u64_free(r->abdications);
> +
> +       free(r, r->mt);
> +}
> +
> +/*
> + * Enqueue n items and maybe drain the ring for some time.
> + *
> + * Returns an errno.
> + */
> +int
> +mp_ring_enqueue(struct mp_ring *r, void **items, int n, int budget)
> +{
> +       union ring_state os, ns;
> +       uint16_t pidx_start, pidx_stop;
> +       int i;
> +
> +       MPASS(items != NULL);
> +       MPASS(n > 0);
> +
>
> *** DIFF OUTPUT TRUNCATED AT 1000 LINES ***
>
>


-- 
-----------------------------------------+-------------------------------
 Prof. Luigi RIZZO, rizzo at iet.unipi.it  . Dip. di Ing. dell'Informazione
 http://www.iet.unipi.it/~luigi/        . Universita` di Pisa
 TEL      +39-050-2211611               . via Diotisalvi 2
 Mobile   +39-338-6809875               . 56122 PISA (Italy)
-----------------------------------------+-------------------------------


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