Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752215AbdHCSXU (ORCPT ); Thu, 3 Aug 2017 14:23:20 -0400 Received: from ale.deltatee.com ([207.54.116.67]:41544 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751891AbdHCSUD (ORCPT ); Thu, 3 Aug 2017 14:20:03 -0400 From: Logan Gunthorpe To: linux-ntb@googlegroups.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jon Mason , Dave Jiang , Allen Hubbe , Bjorn Helgaas , Greg Kroah-Hartman , Kurt Schwemmer , Stephen Bates , Serge Semin , Logan Gunthorpe Date: Thu, 3 Aug 2017 12:19:45 -0600 Message-Id: <20170803181954.4154-7-logang@deltatee.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170803181954.4154-1-logang@deltatee.com> References: <20170803181954.4154-1-logang@deltatee.com> X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-ntb@googlegroups.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, jdmason@kudzu.us, dave.jiang@intel.com, Allen.Hubbe@emc.com, bhelgaas@google.com, gregkh@linuxfoundation.org, kurt.schwemmer@microsemi.com, sbates@raithlin.com, fancer.lancer@gmail.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v4 06/15] NTB: Add check and comment for link up to mw_count() and mw_get_align() X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +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 Content-Length: 2027 Lines: 50 Adds a comment and a check to ntb_mw_get_align() so that it always fails if the function is called before the link is up. Also adds a comment to ntb_mw_count() to note that it may return 0 if it is called before the link is up. This is to prevent accidental mis-use in clients that are testing on hardware that this doesn't matter for. Signed-off-by: Logan Gunthorpe Acked-by: Allen Hubbe --- include/linux/ntb.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/include/linux/ntb.h b/include/linux/ntb.h index 609e232c00da..47f2966cfd7f 100644 --- a/include/linux/ntb.h +++ b/include/linux/ntb.h @@ -730,7 +730,8 @@ static inline int ntb_link_disable(struct ntb_dev *ntb) * Hardware and topology may support a different number of memory windows. * Moreover different peer devices can support different number of memory * windows. Simply speaking this method returns the number of possible inbound - * memory windows to share with specified peer device. + * memory windows to share with specified peer device. Note: this may return + * zero if the link is not up yet. * * Return: the number of memory windows. */ @@ -751,7 +752,7 @@ static inline int ntb_mw_count(struct ntb_dev *ntb, int pidx) * Get the alignments of an inbound memory window with specified index. * NULL may be given for any output parameter if the value is not needed. * The alignment and size parameters may be used for allocation of proper - * shared memory. + * shared memory. Note: this must only be called when the link is up. * * Return: Zero on success, otherwise a negative error number. */ @@ -760,6 +761,9 @@ static inline int ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int widx, resource_size_t *size_align, resource_size_t *size_max) { + if (!(ntb_link_is_up(ntb, NULL, NULL) & (1 << pidx))) + return -ENOTCONN; + return ntb->ops->mw_get_align(ntb, pidx, widx, addr_align, size_align, size_max); } -- 2.11.0