Merge tag 'ntb-4.2' of git://github.com/jonmason/ntb

Pull NTB updates from Jon Mason:
 "This includes a pretty significant reworking of the NTB core code, but
  has already produced some significant performance improvements.

  An abstraction layer was added to allow the hardware and clients to be
  easily added.  This required rewriting the NTB transport layer for
  this abstraction layer.  This modification will allow future "high
  performance" NTB clients.

  In addition to this change, a number of performance modifications were
  added.  These changes include NUMA enablement, using CPU memcpy
  instead of asyncdma, and modification of NTB layer MTU size"

* tag 'ntb-4.2' of git://github.com/jonmason/ntb: (22 commits)
  NTB: Add split BAR output for debugfs stats
  NTB: Change WARN_ON_ONCE to pr_warn_once on unsafe
  NTB: Print driver name and version in module init
  NTB: Increase transport MTU to 64k from 16k
  NTB: Rename Intel code names to platform names
  NTB: Default to CPU memcpy for performance
  NTB: Improve performance with write combining
  NTB: Use NUMA memory in Intel driver
  NTB: Use NUMA memory and DMA chan in transport
  NTB: Rate limit ntb_qp_link_work
  NTB: Add tool test client
  NTB: Add ping pong test client
  NTB: Add parameters for Intel SNB B2B addresses
  NTB: Reset transport QP link stats on down
  NTB: Do not advance transport RX on link down
  NTB: Differentiate transport link down messages
  NTB: Check the device ID to set errata flags
  NTB: Enable link for Intel root port mode in probe
  NTB: Read peer info from local SPAD in transport
  NTB: Split ntb_hw_intel and ntb_transport drivers
  ...

Documentation/ntb.txt

@@ -0,0 +1,127 @@
+# NTB Drivers
+
+NTB (Non-Transparent Bridge) is a type of PCI-Express bridge chip that connects
+the separate memory systems of two computers to the same PCI-Express fabric.
+Existing NTB hardware supports a common feature set, including scratchpad
+registers, doorbell registers, and memory translation windows.  Scratchpad
+registers are read-and-writable registers that are accessible from either side
+of the device, so that peers can exchange a small amount of information at a
+fixed address.  Doorbell registers provide a way for peers to send interrupt
+events.  Memory windows allow translated read and write access to the peer
+memory.
+
+## NTB Core Driver (ntb)
+
+The NTB core driver defines an api wrapping the common feature set, and allows
+clients interested in NTB features to discover NTB the devices supported by
+hardware drivers.  The term "client" is used here to mean an upper layer
+component making use of the NTB api.  The term "driver," or "hardware driver,"
+is used here to mean a driver for a specific vendor and model of NTB hardware.
+
+## NTB Client Drivers
+
+NTB client drivers should register with the NTB core driver.  After
+registering, the client probe and remove functions will be called appropriately
+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 Ping Pong Test Client (ntb\_pingpong)
+
+The Ping Pong test client serves as a demonstration to exercise the doorbell
+and scratchpad registers of NTB hardware, and as an example simple NTB client.
+Ping Pong enables the link when started, waits for the NTB link to come up, and
+then proceeds to read and write the doorbell scratchpad registers of the NTB.
+The peers interrupt each other using a bit mask of doorbell bits, which is
+shifted by one in each round, to test the behavior of multiple doorbell bits
+and interrupt vectors.  The Ping Pong driver also reads the first local
+scratchpad, and writes the value plus one to the first peer scratchpad, each
+round before writing the peer doorbell register.
+
+Module Parameters:
+
+* unsafe - Some hardware has known issues with scratchpad and doorbell
+	registers.  By default, Ping Pong will not attempt to exercise such
+	hardware.  You may override this behavior at your own risk by setting
+	unsafe=1.
+* delay\_ms - Specify the delay between receiving a doorbell
+	interrupt event and setting the peer doorbell register for the next
+	round.
+* init\_db - Specify the doorbell bits to start new series of rounds.  A new
+	series begins once all the doorbell bits have been shifted out of
+	range.
+* dyndbg - It is suggested to specify dyndbg=+p when loading this module, and
+	then to observe debugging output on the console.
+
+### NTB Tool Test Client (ntb\_tool)
+
+The Tool test client serves for debugging, primarily, ntb hardware and drivers.
+The Tool provides access through debugfs for reading, setting, and clearing the
+NTB doorbell, and reading and writing scratchpads.
+
+The Tool does not currently have any module parameters.
+
+Debugfs Files:
+
+* *debugfs*/ntb\_tool/*hw*/ - A directory in debugfs will be created for each
+	NTB device probed by the tool.  This directory is shortened to *hw*
+	below.
+* *hw*/db - This file is used to read, set, and clear the local doorbell.  Not
+	all operations may be supported by all hardware.  To read the doorbell,
+	read the file.  To set the doorbell, write `s` followed by the bits to
+	set (eg: `echo 's 0x0101' > db`).  To clear the doorbell, write `c`
+	followed by the bits to clear.
+* *hw*/mask - This file is used to read, set, and clear the local doorbell mask.
+	See *db* for details.
+* *hw*/peer\_db - This file is used to read, set, and clear the peer doorbell.
+	See *db* for details.
+* *hw*/peer\_mask - This file is used to read, set, and clear the peer doorbell
+	mask.  See *db* for details.
+* *hw*/spad - This file is used to read and write local scratchpads.  To read
+	the values of all scratchpads, read the file.  To write values, write a
+	series of pairs of scratchpad number and value
+	(eg: `echo '4 0x123 7 0xabc' > spad`
+	# to set scratchpads `4` and `7` to `0x123` and `0xabc`, respectively).
+* *hw*/peer\_spad - This file is used to read and write peer scratchpads.  See
+	*spad* for details.
+
+## 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.
+* xeon\_b2b\_usd\_bar2\_addr64 - If using B2B topology on Xeon hardware, use
+	this 64 bit address on the bus between the NTB devices for the window
+	at BAR2, on the upstream side of the link.
+* xeon\_b2b\_usd\_bar4\_addr64 - See *xeon\_b2b\_bar2\_addr64*.
+* xeon\_b2b\_usd\_bar4\_addr32 - See *xeon\_b2b\_bar2\_addr64*.
+* xeon\_b2b\_usd\_bar5\_addr32 - See *xeon\_b2b\_bar2\_addr64*.
+* xeon\_b2b\_dsd\_bar2\_addr64 - See *xeon\_b2b\_bar2\_addr64*.
+* xeon\_b2b\_dsd\_bar4\_addr64 - See *xeon\_b2b\_bar2\_addr64*.
+* xeon\_b2b\_dsd\_bar4\_addr32 - See *xeon\_b2b\_bar2\_addr64*.
+* xeon\_b2b\_dsd\_bar5\_addr32 - See *xeon\_b2b\_bar2\_addr64*.

MAINTAINERS

@@ -7212,15 +7212,25 @@ F:	drivers/power/bq27x00_battery.c
 F:	drivers/power/isp1704_charger.c
 F:	drivers/power/rx51_battery.c
 
-NTB DRIVER
+NTB DRIVER CORE
 M:	Jon Mason <[email protected]>
 M:	Dave Jiang <[email protected]>
+M:	Allen Hubbe <[email protected]>
 S:	Supported
 W:	https://github.com/jonmason/ntb/wiki
 T:	git git://github.com/jonmason/ntb.git
 F:	drivers/ntb/
 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]>

drivers/net/Kconfig

@@ -217,8 +217,8 @@ config NET_POLL_CONTROLLER
 	def_bool NETPOLL
 
 config NTB_NETDEV
-	tristate "Virtual Ethernet over NTB"
-	depends on NTB
+	tristate "Virtual Ethernet over NTB Transport"
+	depends on NTB_TRANSPORT
 
 config RIONET
 	tristate "RapidIO Ethernet over messaging driver support"

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]>
@@ -50,6 +52,7 @@
 #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,
@@ -407,16 +413,16 @@ 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_register_client(&ntb_netdev_client);
+	return ntb_transport_register_client(&ntb_netdev_client);
 }
 module_init(ntb_netdev_init_module);
 
 static void __exit ntb_netdev_exit_module(void)
 {
-	ntb_unregister_client(&ntb_netdev_client);
-	ntb_unregister_client_dev(KBUILD_MODNAME);
+	ntb_transport_unregister_client(&ntb_netdev_client);
+	ntb_transport_unregister_client_dev(KBUILD_MODNAME);
 }
 module_exit(ntb_netdev_exit_module);

drivers/ntb/Kconfig

@@ -1,13 +1,28 @@
-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"
+
+source "drivers/ntb/test/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

@@ -1,3 +1,2 @@
-obj-$(CONFIG_NTB) += ntb.o
-
-ntb-objs := ntb_hw.o ntb_transport.o
+obj-$(CONFIG_NTB) += ntb.o hw/ test/
+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