tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
net: introduce generic switch devices support
The goal of this is to provide a possibility to support various switch
chips. Drivers should implement relevant ndos to do so. Now there is
only one ndo defined:
- for getting physical switch id is in place.
Note that user can use random port netdevice to access the switch.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Reviewed-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
authored by
Jiri Pirko
and committed by
David S. Miller
007f790c
02637fce
+161
+59
Documentation/networking/switchdev.txt
+59
Documentation/networking/switchdev.txt
···
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Switch (and switch-ish) device drivers HOWTO
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===========================
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Please note that the word "switch" is here used in very generic meaning.
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This include devices supporting L2/L3 but also various flow offloading chips,
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including switches embedded into SR-IOV NICs.
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Lets describe a topology a bit. Imagine the following example:
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+----------------------------+ +---------------+
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| SOME switch chip | | CPU |
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+----------------------------+ +---------------+
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port1 port2 port3 port4 MNGMNT | PCI-E |
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| | | | | +---------------+
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PHY PHY | | | | NIC0 NIC1
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| | | | | |
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| | +- PCI-E -+ | |
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| +------- MII -------+ |
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+------------- MII ------------+
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+
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In this example, there are two independent lines between the switch silicon
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and CPU. NIC0 and NIC1 drivers are not aware of a switch presence. They are
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separate from the switch driver. SOME switch chip is by managed by a driver
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via PCI-E device MNGMNT. Note that MNGMNT device, NIC0 and NIC1 may be
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connected to some other type of bus.
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Now, for the previous example show the representation in kernel:
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+----------------------------+ +---------------+
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| SOME switch chip | | CPU |
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+----------------------------+ +---------------+
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sw0p0 sw0p1 sw0p2 sw0p3 MNGMNT | PCI-E |
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| | | | | +---------------+
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PHY PHY | | | | eth0 eth1
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| | | | | |
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| | +- PCI-E -+ | |
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| +------- MII -------+ |
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+------------- MII ------------+
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Lets call the example switch driver for SOME switch chip "SOMEswitch". This
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driver takes care of PCI-E device MNGMNT. There is a netdevice instance sw0pX
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created for each port of a switch. These netdevices are instances
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of "SOMEswitch" driver. sw0pX netdevices serve as a "representation"
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of the switch chip. eth0 and eth1 are instances of some other existing driver.
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The only difference of the switch-port netdevice from the ordinary netdevice
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is that is implements couple more NDOs:
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ndo_switch_parent_id_get - This returns the same ID for two port netdevices
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of the same physical switch chip. This is
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mandatory to be implemented by all switch drivers
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and serves the caller for recognition of a port
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netdevice.
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ndo_switch_parent_* - Functions that serve for a manipulation of the switch
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chip itself (it can be though of as a "parent" of the
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port, therefore the name). They are not port-specific.
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Caller might use arbitrary port netdevice of the same
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switch and it will make no difference.
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ndo_switch_port_* - Functions that serve for a port-specific manipulation.
+7
MAINTAINERS
+7
MAINTAINERS
···
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F: arch/*/kernel/pci-swiotlb.c
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F: include/linux/swiotlb.h
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SWITCHDEV
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M: Jiri Pirko <jiri@resnulli.us>
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L: netdev@vger.kernel.org
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S: Supported
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F: net/switchdev/
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F: include/net/switchdev.h
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SYNOPSYS ARC ARCHITECTURE
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M: Vineet Gupta <vgupta@synopsys.com>
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S: Supported
+10
include/linux/netdevice.h
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include/linux/netdevice.h
···
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* performing GSO on a packet. The device returns true if it is
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* able to GSO the packet, false otherwise. If the return value is
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* false the stack will do software GSO.
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*
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* int (*ndo_switch_parent_id_get)(struct net_device *dev,
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* struct netdev_phys_item_id *psid);
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* Called to get an ID of the switch chip this port is part of.
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* If driver implements this, it indicates that it represents a port
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* of a switch chip.
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*/
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struct net_device_ops {
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int (*ndo_init)(struct net_device *dev);
···
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int (*ndo_get_lock_subclass)(struct net_device *dev);
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bool (*ndo_gso_check) (struct sk_buff *skb,
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struct net_device *dev);
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#ifdef CONFIG_NET_SWITCHDEV
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int (*ndo_switch_parent_id_get)(struct net_device *dev,
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struct netdev_phys_item_id *psid);
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#endif
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};
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/**
+30
include/net/switchdev.h
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include/net/switchdev.h
···
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/*
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* include/net/switchdev.h - Switch device API
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* Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#ifndef _LINUX_SWITCHDEV_H_
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#define _LINUX_SWITCHDEV_H_
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#include <linux/netdevice.h>
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#ifdef CONFIG_NET_SWITCHDEV
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int netdev_switch_parent_id_get(struct net_device *dev,
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struct netdev_phys_item_id *psid);
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#else
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static inline int netdev_switch_parent_id_get(struct net_device *dev,
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struct netdev_phys_item_id *psid)
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{
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return -EOPNOTSUPP;
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}
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#endif
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#endif /* _LINUX_SWITCHDEV_H_ */
+1
net/Kconfig
+1
net/Kconfig
+3
net/Makefile
+3
net/Makefile
+13
net/switchdev/Kconfig
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net/switchdev/Kconfig
···
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#
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# Configuration for Switch device support
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#
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config NET_SWITCHDEV
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boolean "Switch (and switch-ish) device support (EXPERIMENTAL)"
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depends on INET
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---help---
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This module provides glue between core networking code and device
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drivers in order to support hardware switch chips in very generic
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meaning of the word "switch". This include devices supporting L2/L3 but
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also various flow offloading chips, including switches embedded into
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SR-IOV NICs.
+5
net/switchdev/Makefile
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net/switchdev/Makefile
+33
net/switchdev/switchdev.c
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net/switchdev/switchdev.c
···
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/*
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* net/switchdev/switchdev.c - Switch device API
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* Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/netdevice.h>
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#include <net/switchdev.h>
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/**
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* netdev_switch_parent_id_get - Get ID of a switch
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* @dev: port device
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* @psid: switch ID
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*
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* Get ID of a switch this port is part of.
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*/
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int netdev_switch_parent_id_get(struct net_device *dev,
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struct netdev_phys_item_id *psid)
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{
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const struct net_device_ops *ops = dev->netdev_ops;
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if (!ops->ndo_switch_parent_id_get)
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return -EOPNOTSUPP;
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return ops->ndo_switch_parent_id_get(dev, psid);
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}
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EXPORT_SYMBOL(netdev_switch_parent_id_get);