From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752620AbdLIABb (ORCPT ); Fri, 8 Dec 2017 19:01:31 -0500 Received: from ale.deltatee.com ([207.54.116.67]:47352 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750941AbdLIAB2 (ORCPT ); Fri, 8 Dec 2017 19:01:28 -0500 From: Logan Gunthorpe To: linux-ntb@googlegroups.com, linux-kernel@vger.kernel.org Cc: Logan Gunthorpe , Jon Mason , Dave Jiang , Allen Hubbe Date: Fri, 8 Dec 2017 17:01:05 -0700 Message-Id: <20171209000106.18259-2-logang@deltatee.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20171209000106.18259-1-logang@deltatee.com> References: <20171209000106.18259-1-logang@deltatee.com> X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-ntb@googlegroups.com, linux-kernel@vger.kernel.org, logang@deltatee.com, jdmason@kudzu.us, dave.jiang@intel.com, Allen.Hubbe@emc.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH] ntb_transport: fix qp count bug X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Cc: Jon Mason Cc: Dave Jiang Cc: Allen Hubbe --- drivers/ntb/ntb_transport.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index 02ca45fdd892..0a778d2cab94 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -1128,8 +1128,8 @@ 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; -- 2.11.0