From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa1.dell-outbound.iphmx.com (esa1.dell-outbound.iphmx.com. [68.232.153.90]) by gmr-mx.google.com with ESMTPS id i9si881735ywc.0.2016.12.03.16.06.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 03 Dec 2016 16:06:01 -0800 (PST) From: "Allen Hubbe" Subject: RE: [PATCH 06/22] NTB: Slightly alter link state NTB API Date: Sat, 3 Dec 2016 19:05:42 -0500 Message-ID: <004101d24dc2$27bbf7f0$7733e7d0$@dell.com> MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit Content-Language: en-us To: 'Serge Semin' , jdmason@kudzu.us, dave.jiang@intel.com, Xiangliang.Yu@amd.com Cc: Sergey.Semin@t-platforms.ru, linux-ntb@googlegroups.com, linux-kernel@vger.kernel.org List-ID: From: Serge Semin > Some minor changes of link state NTB API. Particularly link_is_up() > method from now shall return a bitfield of link states for all accessible > port indexes. Looks good. I plan to ack. See comment on ntb_link_enable. > > Signed-off-by: Serge Semin > > --- > include/linux/ntb.h | 31 ++++++++++++++++--------------- > 1 file changed, 16 insertions(+), 15 deletions(-) > > diff --git a/include/linux/ntb.h b/include/linux/ntb.h > index fc9d034..a59a155 100644 > --- a/include/linux/ntb.h > +++ b/include/linux/ntb.h > @@ -221,7 +221,7 @@ struct ntb_dev_ops { > int (*peer_port_number)(struct ntb_dev *ntb, int pidx); > int (*peer_port_idx)(struct ntb_dev *ntb, int port); > > - int (*link_is_up)(struct ntb_dev *ntb, > + u64 (*link_is_up)(struct ntb_dev *ntb, > enum ntb_speed *speed, enum ntb_width *width); > int (*link_enable)(struct ntb_dev *ntb, > enum ntb_speed max_speed, enum ntb_width max_width); > @@ -567,25 +567,26 @@ static inline int ntb_peer_port_idx(struct ntb_dev *ntb, int port) > * state once after every link event. It is safe to query the link state in > * the context of the link event callback. > * > - * Return: One if the link is up, zero if the link is down, otherwise a > - * negative value indicating the error number. > + * Return: bitfield of indexed ports link state: bit is set/cleared if the > + * link is up/down respectively, otherwise a negative value indicating > + * an error number. > */ > -static inline int ntb_link_is_up(struct ntb_dev *ntb, > +static inline u64 ntb_link_is_up(struct ntb_dev *ntb, > enum ntb_speed *speed, enum ntb_width *width) > { > return ntb->ops->link_is_up(ntb, speed, width); > } > > /** > - * ntb_link_enable() - enable the link on the secondary side of the ntb > + * ntb_link_enable() - enable the link of the ntb Maybe: enable the local port ntb connection. The description that follows is good for B2B topology, but the description including "link training" might not be accurate for multi-port devices. > * @ntb: NTB device context. > * @max_speed: The maximum link speed expressed as PCIe generation number. > * @max_width: The maximum link width expressed as the number of PCIe lanes. > * > - * Enable the link on the secondary side of the ntb. This can only be done > - * from the primary side of the ntb in primary or b2b topology. The ntb device > - * should train the link to its maximum speed and width, or the requested speed > - * and width, whichever is smaller, if supported. > + * Enable the NTB/PCIe link on the local or remote (for bridge-to-bridge > + * topology) side of the bridge. The ntb device should train the link to its > + * maximum speed and width, or the requested speed and width, whichever is > + * smaller, if supported. > * > * Return: Zero on success, otherwise an error number. > */ > @@ -597,14 +598,14 @@ static inline int ntb_link_enable(struct ntb_dev *ntb, > } > > /** > - * ntb_link_disable() - disable the link on the secondary side of the ntb > + * ntb_link_disable() - disable the link of the ntb > * @ntb: NTB device context. > * > - * Disable the link on the secondary side of the ntb. This can only be > - * done from the primary side of the ntb in primary or b2b topology. The ntb > - * device should disable the link. Returning from this call must indicate that > - * a barrier has passed, though with no more writes may pass in either > - * direction across the link, except if this call returns an error number. > + * Disable the link on the local or remote (for b2b topology) of the ntb. > + * The ntb device should disable the link. Returning from this call must > + * indicate that a barrier has passed, though with no more writes may pass in > + * either direction across the link, except if this call returns an error > + * number. > * > * Return: Zero on success, otherwise an error number. > */ > -- > 2.6.6