Commit 6d7c8e1b authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
  ...
parents 1b3618b6 bf44fe46

Documentation/ntb.txt

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+127 −0
Original line number Diff line number Diff line 
# 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

+11 −1
Original line number Diff line number Diff line
@@ -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 <jdmason@kudzu.us>

M:	Dave Jiang <dave.jiang@intel.com>

M:	Allen Hubbe <Allen.Hubbe@emc.com>

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 <jdmason@kudzu.us>

M:	Dave Jiang <dave.jiang@intel.com>

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 <anton@tuxera.com>

drivers/net/Kconfig

+2 −2
Original line number Diff line number Diff line
@@ -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

+32 −26
Original line number Diff line number Diff line
@@ -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 <jon.mason@intel.com>
@@ -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:

		netif_carrier_off(ndev);

		break;

	case NTB_LINK_UP:

		if (!ntb_transport_link_query(dev->qp))

			return;



	if (link_is_up) {

		if (ntb_transport_link_query(dev->qp))

			netif_carrier_on(ndev);

		break;

	default:

		netdev_warn(ndev, "Unsupported event type %d\n", status);

	} else {

		netif_carrier_off(ndev);

	}

}
@@ -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 @@ err: 
	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

+27 −12
Original line number Diff line number Diff line 
config NTB

       tristate "Intel Non-Transparent Bridge support"

menuconfig NTB

	tristate "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
@@ -11,3 +10,19 @@ config NTB 


	 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

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