From 51aaa54eb9e9f01878aa5d62277fd156e458dfe1 Mon Sep 17 00:00:00 2001 From: Joachim Fenkes Date: Fri, 2 Nov 2007 15:41:49 +0200 Subject: IB/ehca: Fix static rate calculation The IPD (inter-packet delay) formula was a little off and assumed a fixed physical link rate; fix the formula and query the actual physical link rate, now that we can get it. Also, refactor the calculation into a common function ehca_calc_ipd() and use that instead of duplicating code. Signed-off-by: Joachim Fenkes Signed-off-by: Roland Dreier --- drivers/infiniband/hw/ehca/ehca_av.c | 48 +++++++++++++++++++++++++++++------- 1 file changed, 39 insertions(+), 9 deletions(-) (limited to 'drivers/infiniband/hw/ehca/ehca_av.c') diff --git a/drivers/infiniband/hw/ehca/ehca_av.c b/drivers/infiniband/hw/ehca/ehca_av.c index 97d108634c5..453eb995c1d 100644 --- a/drivers/infiniband/hw/ehca/ehca_av.c +++ b/drivers/infiniband/hw/ehca/ehca_av.c @@ -50,6 +50,38 @@ static struct kmem_cache *av_cache; +int ehca_calc_ipd(struct ehca_shca *shca, int port, + enum ib_rate path_rate, u32 *ipd) +{ + int path = ib_rate_to_mult(path_rate); + int link, ret; + struct ib_port_attr pa; + + if (path_rate == IB_RATE_PORT_CURRENT) { + *ipd = 0; + return 0; + } + + if (unlikely(path < 0)) { + ehca_err(&shca->ib_device, "Invalid static rate! path_rate=%x", + path_rate); + return -EINVAL; + } + + ret = ehca_query_port(&shca->ib_device, port, &pa); + if (unlikely(ret < 0)) { + ehca_err(&shca->ib_device, "Failed to query port ret=%i", ret); + return ret; + } + + link = ib_width_enum_to_int(pa.active_width) * pa.active_speed; + + /* IPD = round((link / path) - 1) */ + *ipd = ((link + (path >> 1)) / path) - 1; + + return 0; +} + struct ib_ah *ehca_create_ah(struct ib_pd *pd, struct ib_ah_attr *ah_attr) { int ret; @@ -69,15 +101,13 @@ struct ib_ah *ehca_create_ah(struct ib_pd *pd, struct ib_ah_attr *ah_attr) av->av.slid_path_bits = ah_attr->src_path_bits; if (ehca_static_rate < 0) { - int ah_mult = ib_rate_to_mult(ah_attr->static_rate); - int ehca_mult = - ib_rate_to_mult(shca->sport[ah_attr->port_num].rate ); - - if (ah_mult >= ehca_mult) - av->av.ipd = 0; - else - av->av.ipd = (ah_mult > 0) ? - ((ehca_mult - 1) / ah_mult) : 0; + u32 ipd; + if (ehca_calc_ipd(shca, ah_attr->port_num, + ah_attr->static_rate, &ipd)) { + ret = -EINVAL; + goto create_ah_exit1; + } + av->av.ipd = ipd; } else av->av.ipd = ehca_static_rate; -- cgit v1.2.3