From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-x242.google.com (mail-qt0-x242.google.com. [2607:f8b0:400d:c0d::242]) by gmr-mx.google.com with ESMTPS id b187si1554743ywd.1.2017.08.01.11.11.39 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 01 Aug 2017 11:11:39 -0700 (PDT) Received: by mail-qt0-x242.google.com with SMTP id u19so2373138qtc.0 for ; Tue, 01 Aug 2017 11:11:39 -0700 (PDT) Return-Path: Date: Tue, 1 Aug 2017 14:11:36 -0400 From: Jon Mason Subject: Re: [PATCH v3 07/16] ntb: add check and comment for link up to mw_count() and mw_get_align() Message-ID: <20170801181136.GD4186@kudzu.us> References: <20170725205753.4735-1-logang@deltatee.com> <20170725205753.4735-8-logang@deltatee.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170725205753.4735-8-logang@deltatee.com> To: Logan Gunthorpe Cc: linux-ntb@googlegroups.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Dave Jiang , Allen Hubbe , Bjorn Helgaas , Greg Kroah-Hartman , Kurt Schwemmer , Stephen Bates , Serge Semin List-ID: On Tue, Jul 25, 2017 at 02:57:44PM -0600, Logan Gunthorpe wrote: > 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 Similar to the last one, I think this is also a bug fix. I'll pull it out, etc. :) Thanks, Jon > --- > 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 > > -- > You received this message because you are subscribed to the Google Groups "linux-ntb" group. > To unsubscribe from this group and stop receiving emails from it, send an email to linux-ntb+unsubscribe@googlegroups.com. > To post to this group, send email to linux-ntb@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/linux-ntb/20170725205753.4735-8-logang%40deltatee.com. > For more options, visit https://groups.google.com/d/optout.