From 91da11f870f00a3322b81c73042291d7f0be5a17 Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Tue, 7 Oct 2008 13:44:02 +0000 Subject: net: Distributed Switch Architecture protocol support Distributed Switch Architecture is a protocol for managing hardware switch chips. It consists of a set of MII management registers and commands to configure the switch, and an ethernet header format to signal which of the ports of the switch a packet was received from or is intended to be sent to. The switches that this driver supports are typically embedded in access points and routers, and a typical setup with a DSA switch looks something like this: +-----------+ +-----------+ | | RGMII | | | +-------+ +------ 1000baseT MDI ("WAN") | | | 6-port +------ 1000baseT MDI ("LAN1") | CPU | | ethernet +------ 1000baseT MDI ("LAN2") | |MIImgmt| switch +------ 1000baseT MDI ("LAN3") | +-------+ w/5 PHYs +------ 1000baseT MDI ("LAN4") | | | | +-----------+ +-----------+ The switch driver presents each port on the switch as a separate network interface to Linux, polls the switch to maintain software link state of those ports, forwards MII management interface accesses to those network interfaces (e.g. as done by ethtool) to the switch, and exposes the switch's hardware statistics counters via the appropriate Linux kernel interfaces. This initial patch supports the MII management interface register layout of the Marvell 88E6123, 88E6161 and 88E6165 switch chips, and supports the "Ethertype DSA" packet tagging format. (There is no officially registered ethertype for the Ethertype DSA packet format, so we just grab a random one. The ethertype to use is programmed into the switch, and the switch driver uses the value of ETH_P_EDSA for this, so this define can be changed at any time in the future if the one we chose is allocated to another protocol or if Ethertype DSA gets its own officially registered ethertype, and everything will continue to work.) Signed-off-by: Lennert Buytenhek Tested-by: Nicolas Pitre Tested-by: Byron Bradley Tested-by: Tim Ellis Tested-by: Peter van Valderen Tested-by: Dirk Teurlings Signed-off-by: David S. Miller --- net/dsa/dsa.c | 369 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 369 insertions(+) create mode 100644 net/dsa/dsa.c (limited to 'net/dsa/dsa.c') diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c new file mode 100644 index 000000000000..6cc5be2ec7f1 --- /dev/null +++ b/net/dsa/dsa.c @@ -0,0 +1,369 @@ +/* + * net/dsa/dsa.c - Hardware switch handling + * Copyright (c) 2008 Marvell Semiconductor + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include +#include +#include +#include +#include "dsa_priv.h" + +char dsa_driver_version[] = "0.1"; + + +/* switch driver registration ***********************************************/ +static DEFINE_MUTEX(dsa_switch_drivers_mutex); +static LIST_HEAD(dsa_switch_drivers); + +void register_switch_driver(struct dsa_switch_driver *drv) +{ + mutex_lock(&dsa_switch_drivers_mutex); + list_add_tail(&drv->list, &dsa_switch_drivers); + mutex_unlock(&dsa_switch_drivers_mutex); +} + +void unregister_switch_driver(struct dsa_switch_driver *drv) +{ + mutex_lock(&dsa_switch_drivers_mutex); + list_del_init(&drv->list); + mutex_unlock(&dsa_switch_drivers_mutex); +} + +static struct dsa_switch_driver * +dsa_switch_probe(struct mii_bus *bus, int sw_addr, char **_name) +{ + struct dsa_switch_driver *ret; + struct list_head *list; + char *name; + + ret = NULL; + name = NULL; + + mutex_lock(&dsa_switch_drivers_mutex); + list_for_each(list, &dsa_switch_drivers) { + struct dsa_switch_driver *drv; + + drv = list_entry(list, struct dsa_switch_driver, list); + + name = drv->probe(bus, sw_addr); + if (name != NULL) { + ret = drv; + break; + } + } + mutex_unlock(&dsa_switch_drivers_mutex); + + *_name = name; + + return ret; +} + + +/* basic switch operations **************************************************/ +static struct dsa_switch * +dsa_switch_setup(struct device *parent, struct dsa_platform_data *pd, + struct mii_bus *bus, struct net_device *dev) +{ + struct dsa_switch *ds; + int ret; + struct dsa_switch_driver *drv; + char *name; + int i; + + /* + * Probe for switch model. + */ + drv = dsa_switch_probe(bus, pd->sw_addr, &name); + if (drv == NULL) { + printk(KERN_ERR "%s: could not detect attached switch\n", + dev->name); + return ERR_PTR(-EINVAL); + } + printk(KERN_INFO "%s: detected a %s switch\n", dev->name, name); + + + /* + * Allocate and initialise switch state. + */ + ds = kzalloc(sizeof(*ds) + drv->priv_size, GFP_KERNEL); + if (ds == NULL) + return ERR_PTR(-ENOMEM); + + ds->pd = pd; + ds->master_netdev = dev; + ds->master_mii_bus = bus; + + ds->drv = drv; + ds->tag_protocol = drv->tag_protocol; + + + /* + * Validate supplied switch configuration. + */ + ds->cpu_port = -1; + for (i = 0; i < DSA_MAX_PORTS; i++) { + char *name; + + name = pd->port_names[i]; + if (name == NULL) + continue; + + if (!strcmp(name, "cpu")) { + if (ds->cpu_port != -1) { + printk(KERN_ERR "multiple cpu ports?!\n"); + ret = -EINVAL; + goto out; + } + ds->cpu_port = i; + } else { + ds->valid_port_mask |= 1 << i; + } + } + + if (ds->cpu_port == -1) { + printk(KERN_ERR "no cpu port?!\n"); + ret = -EINVAL; + goto out; + } + + + /* + * If we use a tagging format that doesn't have an ethertype + * field, make sure that all packets from this point on get + * sent to the tag format's receive function. (Which will + * discard received packets until we set ds->ports[] below.) + */ + wmb(); + dev->dsa_ptr = (void *)ds; + + + /* + * Do basic register setup. + */ + ret = drv->setup(ds); + if (ret < 0) + goto out; + + ret = drv->set_addr(ds, dev->dev_addr); + if (ret < 0) + goto out; + + ds->slave_mii_bus = mdiobus_alloc(); + if (ds->slave_mii_bus == NULL) { + ret = -ENOMEM; + goto out; + } + dsa_slave_mii_bus_init(ds); + + ret = mdiobus_register(ds->slave_mii_bus); + if (ret < 0) + goto out_free; + + + /* + * Create network devices for physical switch ports. + */ + wmb(); + for (i = 0; i < DSA_MAX_PORTS; i++) { + struct net_device *slave_dev; + + if (!(ds->valid_port_mask & (1 << i))) + continue; + + slave_dev = dsa_slave_create(ds, parent, i, pd->port_names[i]); + if (slave_dev == NULL) { + printk(KERN_ERR "%s: can't create dsa slave " + "device for port %d(%s)\n", + dev->name, i, pd->port_names[i]); + continue; + } + + ds->ports[i] = slave_dev; + } + + return ds; + +out_free: + mdiobus_free(ds->slave_mii_bus); +out: + dev->dsa_ptr = NULL; + kfree(ds); + return ERR_PTR(ret); +} + +static void dsa_switch_destroy(struct dsa_switch *ds) +{ +} + + +/* link polling *************************************************************/ +static void dsa_link_poll_work(struct work_struct *ugly) +{ + struct dsa_switch *ds; + + ds = container_of(ugly, struct dsa_switch, link_poll_work); + + ds->drv->poll_link(ds); + mod_timer(&ds->link_poll_timer, round_jiffies(jiffies + HZ)); +} + +static void dsa_link_poll_timer(unsigned long _ds) +{ + struct dsa_switch *ds = (void *)_ds; + + schedule_work(&ds->link_poll_work); +} + + +/* platform driver init and cleanup *****************************************/ +static int dev_is_class(struct device *dev, void *class) +{ + if (dev->class != NULL && !strcmp(dev->class->name, class)) + return 1; + + return 0; +} + +static struct device *dev_find_class(struct device *parent, char *class) +{ + if (dev_is_class(parent, class)) { + get_device(parent); + return parent; + } + + return device_find_child(parent, class, dev_is_class); +} + +static struct mii_bus *dev_to_mii_bus(struct device *dev) +{ + struct device *d; + + d = dev_find_class(dev, "mdio_bus"); + if (d != NULL) { + struct mii_bus *bus; + + bus = to_mii_bus(d); + put_device(d); + + return bus; + } + + return NULL; +} + +static struct net_device *dev_to_net_device(struct device *dev) +{ + struct device *d; + + d = dev_find_class(dev, "net"); + if (d != NULL) { + struct net_device *nd; + + nd = to_net_dev(d); + dev_hold(nd); + put_device(d); + + return nd; + } + + return NULL; +} + +static int dsa_probe(struct platform_device *pdev) +{ + static int dsa_version_printed; + struct dsa_platform_data *pd = pdev->dev.platform_data; + struct net_device *dev; + struct mii_bus *bus; + struct dsa_switch *ds; + + if (!dsa_version_printed++) + printk(KERN_NOTICE "Distributed Switch Architecture " + "driver version %s\n", dsa_driver_version); + + if (pd == NULL || pd->mii_bus == NULL || pd->netdev == NULL) + return -EINVAL; + + bus = dev_to_mii_bus(pd->mii_bus); + if (bus == NULL) + return -EINVAL; + + dev = dev_to_net_device(pd->netdev); + if (dev == NULL) + return -EINVAL; + + if (dev->dsa_ptr != NULL) { + dev_put(dev); + return -EEXIST; + } + + ds = dsa_switch_setup(&pdev->dev, pd, bus, dev); + if (IS_ERR(ds)) { + dev_put(dev); + return PTR_ERR(ds); + } + + if (ds->drv->poll_link != NULL) { + INIT_WORK(&ds->link_poll_work, dsa_link_poll_work); + init_timer(&ds->link_poll_timer); + ds->link_poll_timer.data = (unsigned long)ds; + ds->link_poll_timer.function = dsa_link_poll_timer; + ds->link_poll_timer.expires = round_jiffies(jiffies + HZ); + add_timer(&ds->link_poll_timer); + } + + platform_set_drvdata(pdev, ds); + + return 0; +} + +static int dsa_remove(struct platform_device *pdev) +{ + struct dsa_switch *ds = platform_get_drvdata(pdev); + + if (ds->drv->poll_link != NULL) + del_timer_sync(&ds->link_poll_timer); + + flush_scheduled_work(); + + dsa_switch_destroy(ds); + + return 0; +} + +static void dsa_shutdown(struct platform_device *pdev) +{ +} + +static struct platform_driver dsa_driver = { + .probe = dsa_probe, + .remove = dsa_remove, + .shutdown = dsa_shutdown, + .driver = { + .name = "dsa", + .owner = THIS_MODULE, + }, +}; + +static int __init dsa_init_module(void) +{ + return platform_driver_register(&dsa_driver); +} +module_init(dsa_init_module); + +static void __exit dsa_cleanup_module(void) +{ + platform_driver_unregister(&dsa_driver); +} +module_exit(dsa_cleanup_module); + +MODULE_AUTHOR("Lennert Buytenhek ") +MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:dsa"); -- cgit v1.2.3 From cf85d08fdf4548ee46657ccfb7f9949a85145db5 Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Tue, 7 Oct 2008 13:45:02 +0000 Subject: dsa: add support for original DSA tagging format Most of the DSA switches currently in the field do not support the Ethertype DSA tagging format that one of the previous patches added support for, but only the original DSA tagging format. The original DSA tagging format carries the same information as the Ethertype DSA tagging format, but with the difference that it does not have an ethertype field. In other words, when receiving a packet that is tagged with an original DSA tag, there is no way of telling in eth_type_trans() that this packet is in fact a DSA-tagged packet. This patch adds a hook into eth_type_trans() which is only compiled in if support for a switch chip that doesn't support Ethertype DSA is selected, and which checks whether there is a DSA switch driver instance attached to this network device which uses the old tag format. If so, it sets the protocol field to ETH_P_DSA without looking at the packet, so that the packet ends up in the right place. Signed-off-by: Lennert Buytenhek Tested-by: Nicolas Pitre Tested-by: Peter van Valderen Tested-by: Dirk Teurlings Signed-off-by: David S. Miller --- net/dsa/dsa.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'net/dsa/dsa.c') diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c index 6cc5be2ec7f1..f8c549281c30 100644 --- a/net/dsa/dsa.c +++ b/net/dsa/dsa.c @@ -202,6 +202,22 @@ static void dsa_switch_destroy(struct dsa_switch *ds) } +/* hooks for ethertype-less tagging formats *********************************/ +/* + * The original DSA tag format and some other tag formats have no + * ethertype, which means that we need to add a little hack to the + * networking receive path to make sure that received frames get + * the right ->protocol assigned to them when one of those tag + * formats is in use. + */ +bool dsa_uses_dsa_tags(void *dsa_ptr) +{ + struct dsa_switch *ds = dsa_ptr; + + return !!(ds->tag_protocol == htons(ETH_P_DSA)); +} + + /* link polling *************************************************************/ static void dsa_link_poll_work(struct work_struct *ugly) { -- cgit v1.2.3 From 396138f03f4521c55ecc3a5dd75d4c56e6323244 Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Tue, 7 Oct 2008 13:46:07 +0000 Subject: dsa: add support for Trailer tagging format This adds support for the Trailer switch tagging format. This is another tagging that doesn't explicitly mark tagged packets with a distinct ethertype, so that we need to add a similar hack in the receive path as for the Original DSA tagging format. Signed-off-by: Lennert Buytenhek Tested-by: Byron Bradley Tested-by: Tim Ellis Signed-off-by: David S. Miller --- net/dsa/dsa.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'net/dsa/dsa.c') diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c index f8c549281c30..33e99462023a 100644 --- a/net/dsa/dsa.c +++ b/net/dsa/dsa.c @@ -217,6 +217,13 @@ bool dsa_uses_dsa_tags(void *dsa_ptr) return !!(ds->tag_protocol == htons(ETH_P_DSA)); } +bool dsa_uses_trailer_tags(void *dsa_ptr) +{ + struct dsa_switch *ds = dsa_ptr; + + return !!(ds->tag_protocol == htons(ETH_P_TRAILER)); +} + /* link polling *************************************************************/ static void dsa_link_poll_work(struct work_struct *ugly) -- cgit v1.2.3