/drivers/net/via-rhine.c
C | 2340 lines | 1627 code | 364 blank | 349 comment | 215 complexity | d2370140a7af1e17aa0ce392c3d01dc8 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
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- /* via-rhine.c: A Linux Ethernet device driver for VIA Rhine family chips. */
- /*
- Written 1998-2001 by Donald Becker.
- Current Maintainer: Roger Luethi <rl@hellgate.ch>
- This software may be used and distributed according to the terms of
- the GNU General Public License (GPL), incorporated herein by reference.
- Drivers based on or derived from this code fall under the GPL and must
- retain the authorship, copyright and license notice. This file is not
- a complete program and may only be used when the entire operating
- system is licensed under the GPL.
- This driver is designed for the VIA VT86C100A Rhine-I.
- It also works with the Rhine-II (6102) and Rhine-III (6105/6105L/6105LOM
- and management NIC 6105M).
- The author may be reached as becker@scyld.com, or C/O
- Scyld Computing Corporation
- 410 Severn Ave., Suite 210
- Annapolis MD 21403
- This driver contains some changes from the original Donald Becker
- version. He may or may not be interested in bug reports on this
- code. You can find his versions at:
- http://www.scyld.com/network/via-rhine.html
- [link no longer provides useful info -jgarzik]
- */
- #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
- #define DRV_NAME "via-rhine"
- #define DRV_VERSION "1.5.0"
- #define DRV_RELDATE "2010-10-09"
- /* A few user-configurable values.
- These may be modified when a driver module is loaded. */
- #define DEBUG
- static int debug = 1; /* 1 normal messages, 0 quiet .. 7 verbose. */
- static int max_interrupt_work = 20;
- /* Set the copy breakpoint for the copy-only-tiny-frames scheme.
- Setting to > 1518 effectively disables this feature. */
- #if defined(__alpha__) || defined(__arm__) || defined(__hppa__) || \
- defined(CONFIG_SPARC) || defined(__ia64__) || \
- defined(__sh__) || defined(__mips__)
- static int rx_copybreak = 1518;
- #else
- static int rx_copybreak;
- #endif
- /* Work-around for broken BIOSes: they are unable to get the chip back out of
- power state D3 so PXE booting fails. bootparam(7): via-rhine.avoid_D3=1 */
- static int avoid_D3;
- /*
- * In case you are looking for 'options[]' or 'full_duplex[]', they
- * are gone. Use ethtool(8) instead.
- */
- /* Maximum number of multicast addresses to filter (vs. rx-all-multicast).
- The Rhine has a 64 element 8390-like hash table. */
- static const int multicast_filter_limit = 32;
- /* Operational parameters that are set at compile time. */
- /* Keep the ring sizes a power of two for compile efficiency.
- The compiler will convert <unsigned>'%'<2^N> into a bit mask.
- Making the Tx ring too large decreases the effectiveness of channel
- bonding and packet priority.
- There are no ill effects from too-large receive rings. */
- #define TX_RING_SIZE 16
- #define TX_QUEUE_LEN 10 /* Limit ring entries actually used. */
- #define RX_RING_SIZE 64
- /* Operational parameters that usually are not changed. */
- /* Time in jiffies before concluding the transmitter is hung. */
- #define TX_TIMEOUT (2*HZ)
- #define PKT_BUF_SZ 1536 /* Size of each temporary Rx buffer.*/
- #include <linux/module.h>
- #include <linux/moduleparam.h>
- #include <linux/kernel.h>
- #include <linux/string.h>
- #include <linux/timer.h>
- #include <linux/errno.h>
- #include <linux/ioport.h>
- #include <linux/interrupt.h>
- #include <linux/pci.h>
- #include <linux/dma-mapping.h>
- #include <linux/netdevice.h>
- #include <linux/etherdevice.h>
- #include <linux/skbuff.h>
- #include <linux/init.h>
- #include <linux/delay.h>
- #include <linux/mii.h>
- #include <linux/ethtool.h>
- #include <linux/crc32.h>
- #include <linux/if_vlan.h>
- #include <linux/bitops.h>
- #include <linux/workqueue.h>
- #include <asm/processor.h> /* Processor type for cache alignment. */
- #include <asm/io.h>
- #include <asm/irq.h>
- #include <asm/uaccess.h>
- #include <linux/dmi.h>
- /* These identify the driver base version and may not be removed. */
- static const char version[] __devinitconst =
- "v1.10-LK" DRV_VERSION " " DRV_RELDATE " Written by Donald Becker";
- /* This driver was written to use PCI memory space. Some early versions
- of the Rhine may only work correctly with I/O space accesses. */
- #ifdef CONFIG_VIA_RHINE_MMIO
- #define USE_MMIO
- #else
- #endif
- MODULE_AUTHOR("Donald Becker <becker@scyld.com>");
- MODULE_DESCRIPTION("VIA Rhine PCI Fast Ethernet driver");
- MODULE_LICENSE("GPL");
- module_param(max_interrupt_work, int, 0);
- module_param(debug, int, 0);
- module_param(rx_copybreak, int, 0);
- module_param(avoid_D3, bool, 0);
- MODULE_PARM_DESC(max_interrupt_work, "VIA Rhine maximum events handled per interrupt");
- MODULE_PARM_DESC(debug, "VIA Rhine debug level (0-7)");
- MODULE_PARM_DESC(rx_copybreak, "VIA Rhine copy breakpoint for copy-only-tiny-frames");
- MODULE_PARM_DESC(avoid_D3, "Avoid power state D3 (work-around for broken BIOSes)");
- #define MCAM_SIZE 32
- #define VCAM_SIZE 32
- /*
- Theory of Operation
- I. Board Compatibility
- This driver is designed for the VIA 86c100A Rhine-II PCI Fast Ethernet
- controller.
- II. Board-specific settings
- Boards with this chip are functional only in a bus-master PCI slot.
- Many operational settings are loaded from the EEPROM to the Config word at
- offset 0x78. For most of these settings, this driver assumes that they are
- correct.
- If this driver is compiled to use PCI memory space operations the EEPROM
- must be configured to enable memory ops.
- III. Driver operation
- IIIa. Ring buffers
- This driver uses two statically allocated fixed-size descriptor lists
- formed into rings by a branch from the final descriptor to the beginning of
- the list. The ring sizes are set at compile time by RX/TX_RING_SIZE.
- IIIb/c. Transmit/Receive Structure
- This driver attempts to use a zero-copy receive and transmit scheme.
- Alas, all data buffers are required to start on a 32 bit boundary, so
- the driver must often copy transmit packets into bounce buffers.
- The driver allocates full frame size skbuffs for the Rx ring buffers at
- open() time and passes the skb->data field to the chip as receive data
- buffers. When an incoming frame is less than RX_COPYBREAK bytes long,
- a fresh skbuff is allocated and the frame is copied to the new skbuff.
- When the incoming frame is larger, the skbuff is passed directly up the
- protocol stack. Buffers consumed this way are replaced by newly allocated
- skbuffs in the last phase of rhine_rx().
- The RX_COPYBREAK value is chosen to trade-off the memory wasted by
- using a full-sized skbuff for small frames vs. the copying costs of larger
- frames. New boards are typically used in generously configured machines
- and the underfilled buffers have negligible impact compared to the benefit of
- a single allocation size, so the default value of zero results in never
- copying packets. When copying is done, the cost is usually mitigated by using
- a combined copy/checksum routine. Copying also preloads the cache, which is
- most useful with small frames.
- Since the VIA chips are only able to transfer data to buffers on 32 bit
- boundaries, the IP header at offset 14 in an ethernet frame isn't
- longword aligned for further processing. Copying these unaligned buffers
- has the beneficial effect of 16-byte aligning the IP header.
- IIId. Synchronization
- The driver runs as two independent, single-threaded flows of control. One
- is the send-packet routine, which enforces single-threaded use by the
- netdev_priv(dev)->lock spinlock. The other thread is the interrupt handler,
- which is single threaded by the hardware and interrupt handling software.
- The send packet thread has partial control over the Tx ring. It locks the
- netdev_priv(dev)->lock whenever it's queuing a Tx packet. If the next slot in
- the ring is not available it stops the transmit queue by
- calling netif_stop_queue.
- The interrupt handler has exclusive control over the Rx ring and records stats
- from the Tx ring. After reaping the stats, it marks the Tx queue entry as
- empty by incrementing the dirty_tx mark. If at least half of the entries in
- the Rx ring are available the transmit queue is woken up if it was stopped.
- IV. Notes
- IVb. References
- Preliminary VT86C100A manual from http://www.via.com.tw/
- http://www.scyld.com/expert/100mbps.html
- http://www.scyld.com/expert/NWay.html
- ftp://ftp.via.com.tw/public/lan/Products/NIC/VT86C100A/Datasheet/VT86C100A03.pdf
- ftp://ftp.via.com.tw/public/lan/Products/NIC/VT6102/Datasheet/VT6102_021.PDF
- IVc. Errata
- The VT86C100A manual is not reliable information.
- The 3043 chip does not handle unaligned transmit or receive buffers, resulting
- in significant performance degradation for bounce buffer copies on transmit
- and unaligned IP headers on receive.
- The chip does not pad to minimum transmit length.
- */
- /* This table drives the PCI probe routines. It's mostly boilerplate in all
- of the drivers, and will likely be provided by some future kernel.
- Note the matching code -- the first table entry matchs all 56** cards but
- second only the 1234 card.
- */
- enum rhine_revs {
- VT86C100A = 0x00,
- VTunknown0 = 0x20,
- VT6102 = 0x40,
- VT8231 = 0x50, /* Integrated MAC */
- VT8233 = 0x60, /* Integrated MAC */
-