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v0.9.3
src/net/netdevice.c
498 строк
12 KB
Michael Brown
Force a netdevice poll in net_tx() before attempting to transmit
04 окт 2007, 17:57
04 окт 2007, 17:57
9ac0377
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/* * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>. * * 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 any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <stdint.h> #include <stdlib.h> #include <stdio.h> #include <byteswap.h> #include <string.h> #include <errno.h> #include <gpxe/if_ether.h> #include <gpxe/iobuf.h> #include <gpxe/tables.h> #include <gpxe/process.h> #include <gpxe/init.h> #include <gpxe/device.h> #include <gpxe/netdevice.h> /** @file * * Network device management * */ /** Registered network-layer protocols */ static struct net_protocol net_protocols[0] __table_start ( struct net_protocol, net_protocols ); static struct net_protocol net_protocols_end[0] __table_end ( struct net_protocol, net_protocols ); /** List of network devices */ struct list_head net_devices = LIST_HEAD_INIT ( net_devices ); /** * Transmit raw packet via network device * * @v netdev Network device * @v iobuf I/O buffer * @ret rc Return status code * * Transmits the packet via the specified network device. This * function takes ownership of the I/O buffer. */ int netdev_tx ( struct net_device *netdev, struct io_buffer *iobuf ) { int rc; DBGC ( netdev, "NETDEV %p transmitting %p (%p+%zx)\n", netdev, iobuf, iobuf->data, iob_len ( iobuf ) ); list_add_tail ( &iobuf->list, &netdev->tx_queue ); if ( ! ( netdev->state & NETDEV_OPEN ) ) { rc = -ENETUNREACH; goto err; } if ( ( rc = netdev->op->transmit ( netdev, iobuf ) ) != 0 ) goto err; return 0; err: netdev_tx_complete_err ( netdev, iobuf, rc ); return rc; } /** * Complete network transmission * * @v netdev Network device * @v iobuf I/O buffer * @v rc Packet status code * * The packet must currently be in the network device's TX queue. */ void netdev_tx_complete_err ( struct net_device *netdev, struct io_buffer *iobuf, int rc ) { /* Update statistics counter */ if ( rc == 0 ) { netdev->stats.tx_ok++; DBGC ( netdev, "NETDEV %p transmission %p complete\n", netdev, iobuf ); } else { netdev->stats.tx_err++; DBGC ( netdev, "NETDEV %p transmission %p failed: %s\n", netdev, iobuf, strerror ( rc ) ); } /* Catch data corruption as early as possible */ assert ( iobuf->list.next != NULL ); assert ( iobuf->list.prev != NULL ); /* Dequeue and free I/O buffer */ list_del ( &iobuf->list ); free_iob ( iobuf ); } /** * Complete network transmission * * @v netdev Network device * @v rc Packet status code * * Completes the oldest outstanding packet in the TX queue. */ void netdev_tx_complete_next_err ( struct net_device *netdev, int rc ) { struct io_buffer *iobuf; list_for_each_entry ( iobuf, &netdev->tx_queue, list ) { netdev_tx_complete_err ( netdev, iobuf, rc ); return; } } /** * Flush device's transmit queue * * @v netdev Network device */ static void netdev_tx_flush ( struct net_device *netdev ) { /* Discard any packets in the TX queue */ while ( ! list_empty ( &netdev->tx_queue ) ) { netdev_tx_complete_next_err ( netdev, -ECANCELED ); } } /** * Add packet to receive queue * * @v netdev Network device * @v iobuf I/O buffer, or NULL * * The packet is added to the network device's RX queue. This * function takes ownership of the I/O buffer. */ void netdev_rx ( struct net_device *netdev, struct io_buffer *iobuf ) { DBGC ( netdev, "NETDEV %p received %p (%p+%zx)\n", netdev, iobuf, iobuf->data, iob_len ( iobuf ) ); /* Enqueue packet */ list_add_tail ( &iobuf->list, &netdev->rx_queue ); /* Update statistics counter */ netdev->stats.rx_ok++; } /** * Discard received packet * * @v netdev Network device * @v iobuf I/O buffer, or NULL * @v rc Packet status code * * The packet is discarded and an RX error is recorded. This function * takes ownership of the I/O buffer. @c iobuf may be NULL if, for * example, the net device wishes to report an error due to being * unable to allocate an I/O buffer. */ void netdev_rx_err ( struct net_device *netdev, struct io_buffer *iobuf, int rc ) { DBGC ( netdev, "NETDEV %p failed to receive %p: %s\n", netdev, iobuf, strerror ( rc ) ); /* Discard packet */ free_iob ( iobuf ); /* Update statistics counter */ netdev->stats.rx_err++; } /** * Poll for completed and received packets on network device * * @v netdev Network device * * Polls the network device for completed transmissions and received * packets. Any received packets will be added to the RX packet queue * via netdev_rx(). */ void netdev_poll ( struct net_device *netdev ) { if ( netdev->state & NETDEV_OPEN ) netdev->op->poll ( netdev ); } /** * Remove packet from device's receive queue * * @v netdev Network device * @ret iobuf I/O buffer, or NULL * * Removes the first packet from the device's RX queue and returns it. * Ownership of the packet is transferred to the caller. */ struct io_buffer * netdev_rx_dequeue ( struct net_device *netdev ) { struct io_buffer *iobuf; list_for_each_entry ( iobuf, &netdev->rx_queue, list ) { list_del ( &iobuf->list ); return iobuf; } return NULL; } /** * Flush device's receive queue * * @v netdev Network device */ static void netdev_rx_flush ( struct net_device *netdev ) { struct io_buffer *iobuf; /* Discard any packets in the RX queue */ while ( ( iobuf = netdev_rx_dequeue ( netdev ) ) ) { netdev_rx_err ( netdev, iobuf, -ECANCELED ); } } /** * Free network device * * @v refcnt Network device reference counter */ static void free_netdev ( struct refcnt *refcnt ) { struct net_device *netdev = container_of ( refcnt, struct net_device, refcnt ); netdev_tx_flush ( netdev ); netdev_rx_flush ( netdev ); free ( netdev ); } /** * Allocate network device * * @v priv_size Size of private data area (net_device::priv) * @ret netdev Network device, or NULL * * Allocates space for a network device and its private data area. */ struct net_device * alloc_netdev ( size_t priv_size ) { struct net_device *netdev; size_t total_len; total_len = ( sizeof ( *netdev ) + priv_size ); netdev = zalloc ( total_len ); if ( netdev ) { netdev->refcnt.free = free_netdev; INIT_LIST_HEAD ( &netdev->tx_queue ); INIT_LIST_HEAD ( &netdev->rx_queue ); netdev->priv = ( ( ( void * ) netdev ) + sizeof ( *netdev ) ); } return netdev; } /** * Register network device * * @v netdev Network device * @ret rc Return status code * * Gives the network device a name and adds it to the list of network * devices. */ int register_netdev ( struct net_device *netdev ) { static unsigned int ifindex = 0; /* Create device name */ snprintf ( netdev->name, sizeof ( netdev->name ), "net%d", ifindex++ ); /* Add to device list */ netdev_get ( netdev ); list_add_tail ( &netdev->list, &net_devices ); DBGC ( netdev, "NETDEV %p registered as %s (phys %s hwaddr %s)\n", netdev, netdev->name, netdev->dev->name, netdev_hwaddr ( netdev ) ); return 0; } /** * Open network device * * @v netdev Network device * @ret rc Return status code */ int netdev_open ( struct net_device *netdev ) { int rc; /* Do nothing if device is already open */ if ( netdev->state & NETDEV_OPEN ) return 0; DBGC ( netdev, "NETDEV %p opening\n", netdev ); /* Open the device */ if ( ( rc = netdev->op->open ( netdev ) ) != 0 ) return rc; /* Mark as opened */ netdev->state |= NETDEV_OPEN; return 0; } /** * Close network device * * @v netdev Network device */ void netdev_close ( struct net_device *netdev ) { /* Do nothing if device is already closed */ if ( ! ( netdev->state & NETDEV_OPEN ) ) return; DBGC ( netdev, "NETDEV %p closing\n", netdev ); /* Close the device */ netdev->op->close ( netdev ); /* Flush TX and RX queues */ netdev_tx_flush ( netdev ); netdev_rx_flush ( netdev ); /* Mark as closed */ netdev->state &= ~NETDEV_OPEN; } /** * Unregister network device * * @v netdev Network device * * Removes the network device from the list of network devices. */ void unregister_netdev ( struct net_device *netdev ) { /* Ensure device is closed */ netdev_close ( netdev ); /* Remove from device list */ list_del ( &netdev->list ); netdev_put ( netdev ); DBGC ( netdev, "NETDEV %p unregistered\n", netdev ); } /** Enable or disable interrupts * * @v netdev Network device * @v enable Interrupts should be enabled */ void netdev_irq ( struct net_device *netdev, int enable ) { netdev->op->irq ( netdev, enable ); } /** * Get network device by name * * @v name Network device name * @ret netdev Network device, or NULL */ struct net_device * find_netdev ( const char *name ) { struct net_device *netdev; list_for_each_entry ( netdev, &net_devices, list ) { if ( strcmp ( netdev->name, name ) == 0 ) return netdev; } return NULL; } /** * Get network device by PCI bus:dev.fn address * * @v bus_type Bus type * @v location Bus location * @ret netdev Network device, or NULL */ struct net_device * find_netdev_by_location ( unsigned int bus_type, unsigned int location ) { struct net_device *netdev; list_for_each_entry ( netdev, &net_devices, list ) { if ( ( netdev->dev->desc.bus_type == bus_type ) && ( netdev->dev->desc.location == location ) ) return netdev; } return NULL; } /** * Transmit network-layer packet * * @v iobuf I/O buffer * @v netdev Network device * @v net_protocol Network-layer protocol * @v ll_dest Destination link-layer address * @ret rc Return status code * * Prepends link-layer headers to the I/O buffer and transmits the * packet via the specified network device. This function takes * ownership of the I/O buffer. */ int net_tx ( struct io_buffer *iobuf, struct net_device *netdev, struct net_protocol *net_protocol, const void *ll_dest ) { /* Force a poll on the netdevice to (potentially) clear any * backed-up TX completions. This is needed on some network * devices to avoid excessive losses due to small TX ring * sizes. */ netdev_poll ( netdev ); return netdev->ll_protocol->tx ( iobuf, netdev, net_protocol, ll_dest ); } /** * Process received network-layer packet * * @v iobuf I/O buffer * @v netdev Network device * @v net_proto Network-layer protocol, in network-byte order * @v ll_source Source link-layer address * @ret rc Return status code */ int net_rx ( struct io_buffer *iobuf, struct net_device *netdev, uint16_t net_proto, const void *ll_source ) { struct net_protocol *net_protocol; /* Hand off to network-layer protocol, if any */ for ( net_protocol = net_protocols ; net_protocol < net_protocols_end ; net_protocol++ ) { if ( net_protocol->net_proto == net_proto ) { return net_protocol->rx ( iobuf, netdev, ll_source ); } } free_iob ( iobuf ); return 0; } /** * Single-step the network stack * * @v process Network stack process * * This polls all interfaces for received packets, and processes * packets from the RX queue. */ static void net_step ( struct process *process __unused ) { struct net_device *netdev; struct io_buffer *iobuf; /* Poll and process each network device */ list_for_each_entry ( netdev, &net_devices, list ) { /* Poll for new packets */ netdev_poll ( netdev ); /* Process at most one received packet. Give priority * to getting packets out of the NIC over processing * the received packets, because we advertise a window * that assumes that we can receive packets from the * NIC faster than they arrive. */ if ( ( iobuf = netdev_rx_dequeue ( netdev ) ) ) { DBGC ( netdev, "NETDEV %p processing %p (%p+%zx)\n", netdev, iobuf, iobuf->data, iob_len ( iobuf ) ); netdev->ll_protocol->rx ( iobuf, netdev ); } } } /** Networking stack process */ struct process net_process __permanent_process = { .step = net_step, };