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Groups > linux.kernel > #1540667

[PATCH v2 3/9] NTB: Alter link-state API to support multi-port devices

From Serge Semin <fancer.lancer@gmail.com>
Newsgroups linux.kernel
Subject [PATCH v2 3/9] NTB: Alter link-state API to support multi-port devices
Date 2016-12-12 22:20 +0100
Message-ID <sNGaR-Uq-3@gated-at.bofh.it> (permalink)
References <sIUet-2Xs-3@gated-at.bofh.it> <sNG1b-R8-9@gated-at.bofh.it>
Organization linux.* mail to news gateway

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Multi-port devices permit the NTB connections between multiple domains,
so a local device can have NTB link being up with one peer and being
down with another. NTB link-state API is appropriately altered to return
a bitfield of the link-states between the local device and possible peers.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>

---
 drivers/ntb/hw/amd/ntb_hw_amd.c     |  2 +-
 drivers/ntb/hw/intel/ntb_hw_intel.c |  2 +-
 include/linux/ntb.h                 | 31 ++++++++++++++++---------------
 3 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/drivers/ntb/hw/amd/ntb_hw_amd.c b/drivers/ntb/hw/amd/ntb_hw_amd.c
index 0b767ef..b6a4291 100644
--- a/drivers/ntb/hw/amd/ntb_hw_amd.c
+++ b/drivers/ntb/hw/amd/ntb_hw_amd.c
@@ -133,7 +133,7 @@ static int amd_link_is_up(struct amd_ntb_dev *ndev)
 	return 0;
 }
 
-static int amd_ntb_link_is_up(struct ntb_dev *ntb,
+static u64 amd_ntb_link_is_up(struct ntb_dev *ntb,
 			      enum ntb_speed *speed,
 			      enum ntb_width *width)
 {
diff --git a/drivers/ntb/hw/intel/ntb_hw_intel.c b/drivers/ntb/hw/intel/ntb_hw_intel.c
index 7e44dc3..f37b6fb 100644
--- a/drivers/ntb/hw/intel/ntb_hw_intel.c
+++ b/drivers/ntb/hw/intel/ntb_hw_intel.c
@@ -1078,7 +1078,7 @@ static int intel_ntb_peer_port_idx(struct ntb_dev *ntb, int port)
 	return 0;
 }
 
-static int intel_ntb_link_is_up(struct ntb_dev *ntb,
+static u64 intel_ntb_link_is_up(struct ntb_dev *ntb,
 				enum ntb_speed *speed,
 				enum ntb_width *width)
 {
diff --git a/include/linux/ntb.h b/include/linux/ntb.h
index 3216689..47ec611 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);
@@ -522,25 +522,26 @@ 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.
  */
-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 local port ntb connection
  * @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. If it's supported the ntb device should train
+ * the link to its maximum speed and width, or the requested speed and width,
+ * whichever is smaller. Some hardware doesn't support PCIe link training, so
+ * the last two arguments will be ignored then.
  *
  * Return: Zero on success, otherwise an error number.
  */
@@ -552,14 +553,14 @@ 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 local port ntb connection
  * @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

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Thread

[PATCH v2 0/9] NTB: Alter kernel API to support multi-port devices Serge Semin <fancer.lancer@gmail.com> - 2016-12-12 22:10 +0100
  [PATCH v2 2/9] NTB: Add indexed ports NTB API Serge Semin <fancer.lancer@gmail.com> - 2016-12-12 22:10 +0100
  [PATCH v2 7/9] NTB: Add new Memory Windows API documentation Serge Semin <fancer.lancer@gmail.com> - 2016-12-12 22:10 +0100
  [PATCH v2 3/9] NTB: Alter link-state API to support multi-port devices Serge Semin <fancer.lancer@gmail.com> - 2016-12-12 22:20 +0100
  [PATCH v2 8/9] NTB: Add PCIe Gen4 link speed Serge Semin <fancer.lancer@gmail.com> - 2016-12-12 22:20 +0100
  [PATCH v2 5/9] NTB: Alter Scratchpads API to support multi-ports devices Serge Semin <fancer.lancer@gmail.com> - 2016-12-12 22:20 +0100
  [PATCH v2 1/9] NTB: Make link-state API being declared first Serge Semin <fancer.lancer@gmail.com> - 2016-12-12 22:20 +0100
  [PATCH v2 4/9] NTB: Alter MW API to support multi-ports devices Serge Semin <fancer.lancer@gmail.com> - 2016-12-12 22:20 +0100
  [PATCH v3 8/9] NTB: Add PCIe Gen4 link speed Serge Semin <fancer.lancer@gmail.com> - 2016-12-14 01:00 +0100
  [PATCH v3 1/9] NTB: Make link-state API being declared first Serge Semin <fancer.lancer@gmail.com> - 2016-12-14 01:00 +0100
    RE: [PATCH v3 1/9] NTB: Make link-state API being declared first "Allen Hubbe" <Allen.Hubbe@dell.com> - 2016-12-14 08:10 +0100
  [PATCH v3 5/9] NTB: Alter Scratchpads API to support multi-ports devices Serge Semin <fancer.lancer@gmail.com> - 2016-12-14 01:00 +0100
    RE: [PATCH v3 5/9] NTB: Alter Scratchpads API to support multi-ports devices "Allen Hubbe" <Allen.Hubbe@dell.com> - 2016-12-14 08:10 +0100
  [PATCH v3 9/9] NTB: Add ntb.h comments Serge Semin <fancer.lancer@gmail.com> - 2016-12-14 01:00 +0100
    RE: [PATCH v3 9/9] NTB: Add ntb.h comments "Allen Hubbe" <Allen.Hubbe@dell.com> - 2016-12-14 08:20 +0100
    [PATCH v3 9/9] NTB: Add ntb.h comments Serge Semin <fancer.lancer@gmail.com> - 2016-12-14 08:20 +0100
      RE: [PATCH v3 9/9] NTB: Add ntb.h comments "Allen Hubbe" <Allen.Hubbe@dell.com> - 2016-12-14 08:20 +0100
      [PATCH v3 9/9] NTB: Add ntb.h comments Serge Semin <fancer.lancer@gmail.com> - 2016-12-20 11:00 +0100
  [PATCH v3 0/9] NTB: Alter kernel API to support multi-port devices Serge Semin <fancer.lancer@gmail.com> - 2016-12-14 01:00 +0100
    [PATCH v3 2/9] NTB: Add indexed ports NTB API Serge Semin <fancer.lancer@gmail.com> - 2016-12-14 01:00 +0100
      RE: [PATCH v3 2/9] NTB: Add indexed ports NTB API "Allen Hubbe" <Allen.Hubbe@dell.com> - 2016-12-14 08:10 +0100
    [PATCH v3 4/9] NTB: Alter MW API to support multi-ports devices Serge Semin <fancer.lancer@gmail.com> - 2016-12-14 01:00 +0100
      RE: [PATCH v3 4/9] NTB: Alter MW API to support multi-ports devices "Allen Hubbe" <Allen.Hubbe@dell.com> - 2016-12-14 08:10 +0100
    [PATCH v3 3/9] NTB: Alter link-state API to support multi-port devices Serge Semin <fancer.lancer@gmail.com> - 2016-12-14 01:00 +0100
    [PATCH v3 6/9] NTB: Add Messaging NTB API Serge Semin <fancer.lancer@gmail.com> - 2016-12-14 01:00 +0100
      [PATCH v3 6/9] NTB: Add Messaging NTB API Serge Semin <fancer.lancer@gmail.com> - 2016-12-20 10:50 +0100
    [PATCH v3 7/9] NTB: Add new Memory Windows API documentation Serge Semin <fancer.lancer@gmail.com> - 2016-12-14 01:00 +0100

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