NTB: Split ntb_hw_intel and ntb_transport drivers

Change ntb_hw_intel to use the new NTB hardware abstraction layer.

Split ntb_transport into its own driver.  Change it to use the new NTB
hardware abstraction layer.

Signed-off-by: Allen Hubbe <[email protected]>
Signed-off-by: Jon Mason <[email protected]>

Author: Allen Hubbe

Documentation/ntb.txt

@@ -26,7 +26,33 @@ as ntb hardware, or hardware drivers, are inserted and removed.  The
 registration uses the Linux Device framework, so it should feel familiar to
 anyone who has written a pci driver.
 
+### NTB Transport Client (ntb\_transport) and NTB Netdev (ntb\_netdev)
+
+The primary client for NTB is the Transport client, used in tandem with NTB
+Netdev.  These drivers function together to create a logical link to the peer,
+across the ntb, to exchange packets of network data.  The Transport client
+establishes a logical link to the peer, and creates queue pairs to exchange
+messages and data.  The NTB Netdev then creates an ethernet device using a
+Transport queue pair.  Network data is copied between socket buffers and the
+Transport queue pair buffer.  The Transport client may be used for other things
+besides Netdev, however no other applications have yet been written.
+
 ## NTB Hardware Drivers
 
 NTB hardware drivers should register devices with the NTB core driver.  After
 registering, clients probe and remove functions will be called.
+
+### NTB Intel Hardware Driver (ntb\_hw\_intel)
+
+The Intel hardware driver supports NTB on Xeon and Atom CPUs.
+
+Module Parameters:
+
+* b2b\_mw\_idx - If the peer ntb is to be accessed via a memory window, then use
+	this memory window to access the peer ntb.  A value of zero or positive
+	starts from the first mw idx, and a negative value starts from the last
+	mw idx.  Both sides MUST set the same value here!  The default value is
+	`-1`.
+* b2b\_mw\_share - If the peer ntb is to be accessed via a memory window, and if
+	the memory window is large enough, still allow the client to use the
+	second half of the memory window for address translation to the peer.

MAINTAINERS

@@ -7007,6 +7007,14 @@ F:	drivers/net/ntb_netdev.c
 F:	include/linux/ntb.h
 F:	include/linux/ntb_transport.h
 
+NTB INTEL DRIVER
+M:	Jon Mason <[email protected]>
+M:	Dave Jiang <[email protected]>
+S:	Supported
+W:	https://github.com/jonmason/ntb/wiki
+T:	git git://github.com/jonmason/ntb.git
+F:	drivers/ntb/hw/intel/
+
 NTFS FILESYSTEM
 M:	Anton Altaparmakov <[email protected]>
 L:	[email protected]

drivers/net/ntb_netdev.c

@@ -5,6 +5,7 @@
  *   GPL LICENSE SUMMARY
  *
  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of version 2 of the GNU General Public License as
@@ -13,6 +14,7 @@
  *   BSD LICENSE
  *
  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
  *
  *   Redistribution and use in source and binary forms, with or without
  *   modification, are permitted provided that the following conditions
@@ -40,7 +42,7 @@
  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * Intel PCIe NTB Network Linux driver
+ * PCIe NTB Network Linux driver
  *
  * Contact Information:
  * Jon Mason <[email protected]>
@@ -49,6 +51,7 @@
 #include <linux/ethtool.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/ntb.h>
 #include <linux/ntb_transport.h>
 
 #define NTB_NETDEV_VER	"0.7"
@@ -70,26 +73,19 @@ struct ntb_netdev {
 
 static LIST_HEAD(dev_list);
 
-static void ntb_netdev_event_handler(void *data, int status)
+static void ntb_netdev_event_handler(void *data, int link_is_up)
 {
 	struct net_device *ndev = data;
 	struct ntb_netdev *dev = netdev_priv(ndev);
 
-	netdev_dbg(ndev, "Event %x, Link %x\n", status,
+	netdev_dbg(ndev, "Event %x, Link %x\n", link_is_up,
 		   ntb_transport_link_query(dev->qp));
 
-	switch (status) {
-	case NTB_LINK_DOWN:
+	if (link_is_up) {
+		if (ntb_transport_link_query(dev->qp))
+			netif_carrier_on(ndev);
+	} else {
 		netif_carrier_off(ndev);
-		break;
-	case NTB_LINK_UP:
-		if (!ntb_transport_link_query(dev->qp))
-			return;
-
-		netif_carrier_on(ndev);
-		break;
-	default:
-		netdev_warn(ndev, "Unsupported event type %d\n", status);
 	}
 }
 
@@ -160,8 +156,6 @@ static netdev_tx_t ntb_netdev_start_xmit(struct sk_buff *skb,
 	struct ntb_netdev *dev = netdev_priv(ndev);
 	int rc;
 
-	netdev_dbg(ndev, "%s: skb len %d\n", __func__, skb->len);
-
 	rc = ntb_transport_tx_enqueue(dev->qp, skb, skb->data, skb->len);
 	if (rc)
 		goto err;
@@ -322,20 +316,26 @@ static const struct ntb_queue_handlers ntb_netdev_handlers = {
 	.event_handler = ntb_netdev_event_handler,
 };
 
-static int ntb_netdev_probe(struct pci_dev *pdev)
+static int ntb_netdev_probe(struct device *client_dev)
 {
+	struct ntb_dev *ntb;
 	struct net_device *ndev;
+	struct pci_dev *pdev;
 	struct ntb_netdev *dev;
 	int rc;
 
-	ndev = alloc_etherdev(sizeof(struct ntb_netdev));
+	ntb = dev_ntb(client_dev->parent);
+	pdev = ntb->pdev;
+	if (!pdev)
+		return -ENODEV;
+
+	ndev = alloc_etherdev(sizeof(*dev));
 	if (!ndev)
 		return -ENOMEM;
 
 	dev = netdev_priv(ndev);
 	dev->ndev = ndev;
 	dev->pdev = pdev;
-	BUG_ON(!dev->pdev);
 	ndev->features = NETIF_F_HIGHDMA;
 
 	ndev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
@@ -349,7 +349,8 @@ static int ntb_netdev_probe(struct pci_dev *pdev)
 	ndev->netdev_ops = &ntb_netdev_ops;
 	ndev->ethtool_ops = &ntb_ethtool_ops;
 
-	dev->qp = ntb_transport_create_queue(ndev, pdev, &ntb_netdev_handlers);
+	dev->qp = ntb_transport_create_queue(ndev, client_dev,
+					     &ntb_netdev_handlers);
 	if (!dev->qp) {
 		rc = -EIO;
 		goto err;
@@ -372,12 +373,17 @@ static int ntb_netdev_probe(struct pci_dev *pdev)
 	return rc;
 }
 
-static void ntb_netdev_remove(struct pci_dev *pdev)
+static void ntb_netdev_remove(struct device *client_dev)
 {
+	struct ntb_dev *ntb;
 	struct net_device *ndev;
+	struct pci_dev *pdev;
 	struct ntb_netdev *dev;
 	bool found = false;
 
+	ntb = dev_ntb(client_dev->parent);
+	pdev = ntb->pdev;
+
 	list_for_each_entry(dev, &dev_list, list) {
 		if (dev->pdev == pdev) {
 			found = true;
@@ -396,7 +402,7 @@ static void ntb_netdev_remove(struct pci_dev *pdev)
 	free_netdev(ndev);
 }
 
-static struct ntb_client ntb_netdev_client = {
+static struct ntb_transport_client ntb_netdev_client = {
 	.driver.name = KBUILD_MODNAME,
 	.driver.owner = THIS_MODULE,
 	.probe = ntb_netdev_probe,
@@ -407,7 +413,7 @@ static int __init ntb_netdev_init_module(void)
 {
 	int rc;
 
-	rc = ntb_register_client_dev(KBUILD_MODNAME);
+	rc = ntb_transport_register_client_dev(KBUILD_MODNAME);
 	if (rc)
 		return rc;
 	return ntb_transport_register_client(&ntb_netdev_client);
@@ -417,6 +423,6 @@ module_init(ntb_netdev_init_module);
 static void __exit ntb_netdev_exit_module(void)
 {
 	ntb_transport_unregister_client(&ntb_netdev_client);
-	ntb_unregister_client_dev(KBUILD_MODNAME);
+	ntb_transport_unregister_client_dev(KBUILD_MODNAME);
 }
 module_exit(ntb_netdev_exit_module);

drivers/ntb/Kconfig

@@ -1,13 +1,26 @@
-config NTB
-       tristate "Intel Non-Transparent Bridge support"
-       depends on PCI
-       depends on X86
-       help
-        The PCI-E Non-transparent bridge hardware is a point-to-point PCI-E bus
-        connecting 2 systems.  When configured, writes to the device's PCI
-        mapped memory will be mirrored to a buffer on the remote system.  The
-        ntb Linux driver uses this point-to-point communication as a method to
-        transfer data from one system to the other.
-
-        If unsure, say N.
+menuconfig NTB
+	tristate "Non-Transparent Bridge support"
+	depends on PCI
+	help
+	 The PCI-E Non-transparent bridge hardware is a point-to-point PCI-E bus
+	 connecting 2 systems.  When configured, writes to the device's PCI
+	 mapped memory will be mirrored to a buffer on the remote system.  The
+	 ntb Linux driver uses this point-to-point communication as a method to
+	 transfer data from one system to the other.
 
+	 If unsure, say N.
+
+if NTB
+
+source "drivers/ntb/hw/Kconfig"
+
+config NTB_TRANSPORT
+	tristate "NTB Transport Client"
+	help
+	 This is a transport driver that enables connected systems to exchange
+	 messages over the ntb hardware.  The transport exposes a queue pair api
+	 to client drivers.
+
+	 If unsure, say N.
+
+endif # NTB

drivers/ntb/Makefile

@@ -1,4 +1,2 @@
-obj-$(CONFIG_NTB) += ntb.o
-obj-$(CONFIG_NTB) += ntb_hw_intel.o
-
-ntb_hw_intel-objs := hw/intel/ntb_hw_intel.o ntb_transport.o
+obj-$(CONFIG_NTB) += ntb.o hw/
+obj-$(CONFIG_NTB_TRANSPORT) += ntb_transport.o

drivers/ntb/hw/Kconfig

@@ -0,0 +1 @@
+source "drivers/ntb/hw/intel/Kconfig"

drivers/ntb/hw/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_NTB_INTEL)	+= intel/

drivers/ntb/hw/intel/Kconfig

@@ -0,0 +1,7 @@
+config NTB_INTEL
+	tristate "Intel Non-Transparent Bridge support"
+	depends on X86_64
+	help
+	 This driver supports Intel NTB on capable Xeon and Atom hardware.
+
+	 If unsure, say N.

drivers/ntb/hw/intel/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_NTB_INTEL) += ntb_hw_intel.o