> Author: np
> Date: Mon Oct 22 23:06:23 2018
> New Revision: 339626
> URL: https://svnweb.freebsd.org/changeset/base/339626
>
> Log:
> cxgbe(4): Use automatic cidx updates with ofld and ctrl queues.
>
> The bits that explicitly request cidx updates do not work reliably with
> all possible WRs that can be sent over the queue. The F_FW_WR_EQUIQ
> requests that still remain may also have to be replaced with explicit
> credit flush WRs in the future.
>
> MFC after: 2 days
Please note in your RFA to re@ your reasons for requesting early
merge to a frozen stable branch. I see good reason for this to
be approved as it would be good to get this in the next snapshot,
but it usually would be rejected if there is not a reason given.
(There is a normal 3 day minimum on MFC after to a frozen branch)
Thanks,
Rod <RE
> Sponsored by: Chelsio Communications
>
> Modified:
> head/sys/dev/cxgbe/t4_sge.c
>
> Modified: head/sys/dev/cxgbe/t4_sge.c
> ==============================================================================
> --- head/sys/dev/cxgbe/t4_sge.c Mon Oct 22 22:24:32 2018
> (r339625)
> +++ head/sys/dev/cxgbe/t4_sge.c Mon Oct 22 23:06:23 2018
> (r339626)
> @@ -2089,12 +2089,13 @@ drain_wrq_wr_list(struct adapter *sc, struct sge_wrq *
>
> if (available < eq->sidx / 4 &&
> atomic_cmpset_int(&eq->equiq, 0, 1)) {
> + /*
> + * XXX: This is not 100% reliable with some
> + * types of WRs. But this is a very unusual
> + * situation for an ofld/ctrl queue anyway.
> + */
> dst->equiq_to_len16 |= htobe32(F_FW_WR_EQUIQ |
> F_FW_WR_EQUEQ);
> - eq->equeqidx = eq->pidx;
> - } else if (IDXDIFF(eq->pidx, eq->equeqidx, eq->sidx) >= 32) {
> - dst->equiq_to_len16 |= htobe32(F_FW_WR_EQUEQ);
> - eq->equeqidx = eq->pidx;
> }
>
> dbdiff += n;
> @@ -2644,12 +2645,13 @@ commit_wrq_wr(struct sge_wrq *wrq, void *w, struct wrq
> available = IDXDIFF(eq->cidx, eq->pidx, eq->sidx) - 1;
> if (available < eq->sidx / 4 &&
> atomic_cmpset_int(&eq->equiq, 0, 1)) {
> + /*
> + * XXX: This is not 100% reliable with some
> + * types of WRs. But this is a very unusual
> + * situation for an ofld/ctrl queue anyway.
> + */
> dst->equiq_to_len16 |= htobe32(F_FW_WR_EQUIQ |
> F_FW_WR_EQUEQ);
> - eq->equeqidx = pidx;
> - } else if (IDXDIFF(eq->pidx, eq->equeqidx, eq->sidx) >=
> 32) {
> - dst->equiq_to_len16 |= htobe32(F_FW_WR_EQUEQ);
> - eq->equeqidx = pidx;
> }
>
> ring_eq_db(wrq->adapter, eq, ndesc);
> @@ -3584,6 +3586,23 @@ free_nm_txq(struct vi_info *vi, struct sge_nm_txq *nm_
> }
> #endif
>
> +/*
> + * Returns a reasonable automatic cidx flush threshold for a given queue
> size.
> + */
> +static u_int
> +qsize_to_fthresh(int qsize)
> +{
> + u_int fthresh;
> +
> + while (!powerof2(qsize))
> + qsize++;
> + fthresh = ilog2(qsize);
> + if (fthresh > X_CIDXFLUSHTHRESH_128)
> + fthresh = X_CIDXFLUSHTHRESH_128;
> +
> + return (fthresh);
> +}
> +
> static int
> ctrl_eq_alloc(struct adapter *sc, struct sge_eq *eq)
> {
> @@ -3607,7 +3626,7 @@ ctrl_eq_alloc(struct adapter *sc, struct sge_eq *eq)
> c.dcaen_to_eqsize =
> htobe32(V_FW_EQ_CTRL_CMD_FBMIN(X_FETCHBURSTMIN_64B) |
> V_FW_EQ_CTRL_CMD_FBMAX(X_FETCHBURSTMAX_512B) |
> - V_FW_EQ_CTRL_CMD_CIDXFTHRESH(X_CIDXFLUSHTHRESH_32) |
> + V_FW_EQ_CTRL_CMD_CIDXFTHRESH(qsize_to_fthresh(qsize)) |
> V_FW_EQ_CTRL_CMD_EQSIZE(qsize));
> c.eqaddr = htobe64(eq->ba);
>
> @@ -3689,12 +3708,13 @@ ofld_eq_alloc(struct adapter *sc, struct vi_info *vi,
> c.alloc_to_len16 = htonl(F_FW_EQ_OFLD_CMD_ALLOC |
> F_FW_EQ_OFLD_CMD_EQSTART | FW_LEN16(c));
> c.fetchszm_to_iqid =
> - htonl(V_FW_EQ_OFLD_CMD_HOSTFCMODE(X_HOSTFCMODE_NONE) |
> + htonl(V_FW_EQ_OFLD_CMD_HOSTFCMODE(X_HOSTFCMODE_STATUS_PAGE) |
> V_FW_EQ_OFLD_CMD_PCIECHN(eq->tx_chan) |
> F_FW_EQ_OFLD_CMD_FETCHRO | V_FW_EQ_OFLD_CMD_IQID(eq->iqid));
> c.dcaen_to_eqsize =
> htobe32(V_FW_EQ_OFLD_CMD_FBMIN(X_FETCHBURSTMIN_64B) |
> V_FW_EQ_OFLD_CMD_FBMAX(X_FETCHBURSTMAX_512B) |
> + V_FW_EQ_OFLD_CMD_CIDXFTHRESH(qsize_to_fthresh(qsize)) |
> V_FW_EQ_OFLD_CMD_EQSIZE(qsize));
> c.eqaddr = htobe64(eq->ba);
>
> @@ -3732,8 +3752,9 @@ alloc_eq(struct adapter *sc, struct vi_info *vi, struc
> if (rc)
> return (rc);
>
> - eq->pidx = eq->cidx = 0;
> - eq->equeqidx = eq->dbidx = 0;
> + eq->pidx = eq->cidx = eq->dbidx = 0;
> + /* Note that equeqidx is not used with sge_wrq (OFLD/CTRL) queues. */
> + eq->equeqidx = 0;
> eq->doorbells = sc->doorbells;
>
> switch (eq->flags & EQ_TYPEMASK) {
>
>
--
Rod Grimes rgri...@freebsd.org
_______________________________________________
svn-src-all@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
