diff options
| author | Logan Gunthorpe <logang@deltatee.com> | 2017-06-05 14:00:53 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-08-30 10:21:54 +0200 |
| commit | 471954c313c57e09839f1381bd4897283d8e6537 (patch) | |
| tree | 5ee9e8960771ca7294a4a49411a308be68e663df /drivers | |
| parent | 4743d1b37a38c36ce2b01741edd33bbaaea9a1b4 (diff) | |
ntb_transport: fix bug calculating num_qps_mw
commit 8e8496e0e9564b66165f5219a4e8ed20b0d3fc6b upstream.
A divide by zero error occurs if qp_count is less than mw_count because
num_qps_mw is calculated to be zero. The calculation appears to be
incorrect.
The requirement is for num_qps_mw to be set to qp_count / mw_count
with any remainder divided among the earlier mws.
For example, if mw_count is 5 and qp_count is 12 then mws 0 and 1
will have 3 qps per window and mws 2 through 4 will have 2 qps per window.
Thus, when mw_num < qp_count % mw_count, num_qps_mw is 1 higher
than when mw_num >= qp_count.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Fixes: e26a5843f7f5 ("NTB: Split ntb_hw_intel and ntb_transport drivers")
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/ntb/ntb_transport.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index c32bda90c562..18414dc17cd0 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -625,7 +625,7 @@ static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt, if (!mw->virt_addr) return -ENOMEM; - if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count) + if (mw_num < qp_count % mw_count) num_qps_mw = qp_count / mw_count + 1; else num_qps_mw = qp_count / mw_count; @@ -1002,7 +1002,7 @@ static int ntb_transport_init_queue(struct ntb_transport_ctx *nt, qp->event_handler = NULL; ntb_qp_link_down_reset(qp); - if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count) + if (mw_num < qp_count % mw_count) num_qps_mw = qp_count / mw_count + 1; else num_qps_mw = qp_count / mw_count; |