iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ntb_transport: fix qp count bug

Browse Source 
commit cb827ee6ccc3e480f0d9c0e8e53eef55be5b0414 upstream.

In cases where there are more mw's than spads/2-2, the mw count gets
reduced to match the limitation. ntb_transport also tries to ensure that
there are fewer qps than mws but uses the full mw count instead of
the reduced one. When this happens, the math in
'ntb_transport_setup_qp_mw' will get confused and result in a kernel
paging request bug.

This patch fixes the bug by reducing qp_count to the reduced mw count
instead of the full mw 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>
This commit is contained in:
Logan Gunthorpe 2017-06-05 14:00:52 -06:00 committed by Greg Kroah-Hartman
parent 4ec0b2c2d2
commit 1aac8ffd61
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/ntb/ntb_transport.c
View File

@ -1065,8 +1065,8 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
qp_count = ilog2(qp_bitmap);
if (max_num_clients && max_num_clients < qp_count)
qp_count = max_num_clients;
else if (mw_count < qp_count)
qp_count = mw_count;
else if (nt->mw_count < qp_count)
qp_count = nt->mw_count;
qp_bitmap &= BIT_ULL(qp_count) - 1;