1 /* winbond-840.c: A Linux PCI network adapter device driver. */
2 /*
3 	Written 1998-2001 by Donald Becker.
4 
5 	This software may be used and distributed according to the terms of
6 	the GNU General Public License (GPL), incorporated herein by reference.
7 	Drivers based on or derived from this code fall under the GPL and must
8 	retain the authorship, copyright and license notice.  This file is not
9 	a complete program and may only be used when the entire operating
10 	system is licensed under the GPL.
11 
12 	The author may be reached as becker@scyld.com, or C/O
13 	Scyld Computing Corporation
14 	410 Severn Ave., Suite 210
15 	Annapolis MD 21403
16 
17 	Support and updates available at
18 	http://www.scyld.com/network/drivers.html
19 
20 	Do not remove the copyright information.
21 	Do not change the version information unless an improvement has been made.
22 	Merely removing my name, as Compex has done in the past, does not count
23 	as an improvement.
24 
25 	Changelog:
26 	* ported to 2.4
27 		???
28 	* spin lock update, memory barriers, new style dma mappings
29 		limit each tx buffer to < 1024 bytes
30 		remove DescIntr from Rx descriptors (that's an Tx flag)
31 		remove next pointer from Tx descriptors
32 		synchronize tx_q_bytes
33 		software reset in tx_timeout
34 			Copyright (C) 2000 Manfred Spraul
35 	* further cleanups
36 		power management.
37 		support for big endian descriptors
38 			Copyright (C) 2001 Manfred Spraul
39   	* ethtool support (jgarzik)
40 	* Replace some MII-related magic numbers with constants (jgarzik)
41 
42 	TODO:
43 	* enable pci_power_off
44 	* Wake-On-LAN
45 */
46 
47 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
48 
49 #define DRV_NAME	"winbond-840"
50 
51 /* Automatically extracted configuration info:
52 probe-func: winbond840_probe
53 config-in: tristate 'Winbond W89c840 Ethernet support' CONFIG_WINBOND_840
54 
55 c-help-name: Winbond W89c840 PCI Ethernet support
56 c-help-symbol: CONFIG_WINBOND_840
57 c-help: This driver is for the Winbond W89c840 chip.  It also works with
58 c-help: the TX9882 chip on the Compex RL100-ATX board.
59 c-help: More specific information and updates are available from
60 c-help: http://www.scyld.com/network/drivers.html
61 */
62 
63 /* The user-configurable values.
64    These may be modified when a driver module is loaded.*/
65 
66 static int debug = 1;			/* 1 normal messages, 0 quiet .. 7 verbose. */
67 static int max_interrupt_work = 20;
68 /* Maximum number of multicast addresses to filter (vs. Rx-all-multicast).
69    The '840 uses a 64 element hash table based on the Ethernet CRC.  */
70 static int multicast_filter_limit = 32;
71 
72 /* Set the copy breakpoint for the copy-only-tiny-frames scheme.
73    Setting to > 1518 effectively disables this feature. */
74 static int rx_copybreak;
75 
76 /* Used to pass the media type, etc.
77    Both 'options[]' and 'full_duplex[]' should exist for driver
78    interoperability.
79    The media type is usually passed in 'options[]'.
80 */
81 #define MAX_UNITS 8		/* More are supported, limit only on options */
82 static int options[MAX_UNITS] = {-1, -1, -1, -1, -1, -1, -1, -1};
83 static int full_duplex[MAX_UNITS] = {-1, -1, -1, -1, -1, -1, -1, -1};
84 
85 /* Operational parameters that are set at compile time. */
86 
87 /* Keep the ring sizes a power of two for compile efficiency.
88    The compiler will convert <unsigned>'%'<2^N> into a bit mask.
89    Making the Tx ring too large decreases the effectiveness of channel
90    bonding and packet priority.
91    There are no ill effects from too-large receive rings. */
92 #define TX_QUEUE_LEN	10		/* Limit ring entries actually used.  */
93 #define TX_QUEUE_LEN_RESTART	5
94 
95 #define TX_BUFLIMIT	(1024-128)
96 
97 /* The presumed FIFO size for working around the Tx-FIFO-overflow bug.
98    To avoid overflowing we don't queue again until we have room for a
99    full-size packet.
100  */
101 #define TX_FIFO_SIZE (2048)
102 #define TX_BUG_FIFO_LIMIT (TX_FIFO_SIZE-1514-16)
103 
104 
105 /* Operational parameters that usually are not changed. */
106 /* Time in jiffies before concluding the transmitter is hung. */
107 #define TX_TIMEOUT  (2*HZ)
108 
109 /* Include files, designed to support most kernel versions 2.0.0 and later. */
110 #include <linux/module.h>
111 #include <linux/kernel.h>
112 #include <linux/string.h>
113 #include <linux/timer.h>
114 #include <linux/errno.h>
115 #include <linux/ioport.h>
116 #include <linux/interrupt.h>
117 #include <linux/pci.h>
118 #include <linux/dma-mapping.h>
119 #include <linux/netdevice.h>
120 #include <linux/etherdevice.h>
121 #include <linux/skbuff.h>
122 #include <linux/init.h>
123 #include <linux/delay.h>
124 #include <linux/ethtool.h>
125 #include <linux/mii.h>
126 #include <linux/rtnetlink.h>
127 #include <linux/crc32.h>
128 #include <linux/bitops.h>
129 #include <linux/uaccess.h>
130 #include <asm/processor.h>		/* Processor type for cache alignment. */
131 #include <asm/io.h>
132 #include <asm/irq.h>
133 
134 #include "tulip.h"
135 
136 #undef PKT_BUF_SZ			/* tulip.h also defines this */
137 #define PKT_BUF_SZ		1536	/* Size of each temporary Rx buffer.*/
138 
139 MODULE_AUTHOR("Donald Becker <becker@scyld.com>");
140 MODULE_DESCRIPTION("Winbond W89c840 Ethernet driver");
141 MODULE_LICENSE("GPL");
142 
143 module_param(max_interrupt_work, int, 0);
144 module_param(debug, int, 0);
145 module_param(rx_copybreak, int, 0);
146 module_param(multicast_filter_limit, int, 0);
147 module_param_array(options, int, NULL, 0);
148 module_param_array(full_duplex, int, NULL, 0);
149 MODULE_PARM_DESC(max_interrupt_work, "winbond-840 maximum events handled per interrupt");
150 MODULE_PARM_DESC(debug, "winbond-840 debug level (0-6)");
151 MODULE_PARM_DESC(rx_copybreak, "winbond-840 copy breakpoint for copy-only-tiny-frames");
152 MODULE_PARM_DESC(multicast_filter_limit, "winbond-840 maximum number of filtered multicast addresses");
153 MODULE_PARM_DESC(options, "winbond-840: Bits 0-3: media type, bit 17: full duplex");
154 MODULE_PARM_DESC(full_duplex, "winbond-840 full duplex setting(s) (1)");
155 
156 /*
157 				Theory of Operation
158 
159 I. Board Compatibility
160 
161 This driver is for the Winbond w89c840 chip.
162 
163 II. Board-specific settings
164 
165 None.
166 
167 III. Driver operation
168 
169 This chip is very similar to the Digital 21*4* "Tulip" family.  The first
170 twelve registers and the descriptor format are nearly identical.  Read a
171 Tulip manual for operational details.
172 
173 A significant difference is that the multicast filter and station address are
174 stored in registers rather than loaded through a pseudo-transmit packet.
175 
176 Unlike the Tulip, transmit buffers are limited to 1KB.  To transmit a
177 full-sized packet we must use both data buffers in a descriptor.  Thus the
178 driver uses ring mode where descriptors are implicitly sequential in memory,
179 rather than using the second descriptor address as a chain pointer to
180 subsequent descriptors.
181 
182 IV. Notes
183 
184 If you are going to almost clone a Tulip, why not go all the way and avoid
185 the need for a new driver?
186 
187 IVb. References
188 
189 http://www.scyld.com/expert/100mbps.html
190 http://www.scyld.com/expert/NWay.html
191 http://www.winbond.com.tw/
192 
193 IVc. Errata
194 
195 A horrible bug exists in the transmit FIFO.  Apparently the chip doesn't
196 correctly detect a full FIFO, and queuing more than 2048 bytes may result in
197 silent data corruption.
198 
199 Test with 'ping -s 10000' on a fast computer.
200 
201 */
202 
203 
204 
205 /*
206   PCI probe table.
207 */
208 enum chip_capability_flags {
209 	CanHaveMII=1, HasBrokenTx=2, AlwaysFDX=4, FDXOnNoMII=8,
210 };
211 
212 static const struct pci_device_id w840_pci_tbl[] = {
213 	{ 0x1050, 0x0840, PCI_ANY_ID, 0x8153,     0, 0, 0 },
214 	{ 0x1050, 0x0840, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 1 },
215 	{ 0x11f6, 0x2011, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 2 },
216 	{ }
217 };
218 MODULE_DEVICE_TABLE(pci, w840_pci_tbl);
219 
220 enum {
221 	netdev_res_size		= 128,	/* size of PCI BAR resource */
222 };
223 
224 struct pci_id_info {
225         const char *name;
226         int drv_flags;		/* Driver use, intended as capability flags. */
227 };
228 
229 static const struct pci_id_info pci_id_tbl[] = {
230 	{ 				/* Sometime a Level-One switch card. */
231 	  "Winbond W89c840",	CanHaveMII | HasBrokenTx | FDXOnNoMII},
232 	{ "Winbond W89c840",	CanHaveMII | HasBrokenTx},
233 	{ "Compex RL100-ATX",	CanHaveMII | HasBrokenTx},
234 	{ }	/* terminate list. */
235 };
236 
237 /* This driver was written to use PCI memory space, however some x86 systems
238    work only with I/O space accesses. See CONFIG_TULIP_MMIO in .config
239 */
240 
241 /* Offsets to the Command and Status Registers, "CSRs".
242    While similar to the Tulip, these registers are longword aligned.
243    Note: It's not useful to define symbolic names for every register bit in
244    the device.  The name can only partially document the semantics and make
245    the driver longer and more difficult to read.
246 */
247 enum w840_offsets {
248 	PCIBusCfg=0x00, TxStartDemand=0x04, RxStartDemand=0x08,
249 	RxRingPtr=0x0C, TxRingPtr=0x10,
250 	IntrStatus=0x14, NetworkConfig=0x18, IntrEnable=0x1C,
251 	RxMissed=0x20, EECtrl=0x24, MIICtrl=0x24, BootRom=0x28, GPTimer=0x2C,
252 	CurRxDescAddr=0x30, CurRxBufAddr=0x34,			/* Debug use */
253 	MulticastFilter0=0x38, MulticastFilter1=0x3C, StationAddr=0x40,
254 	CurTxDescAddr=0x4C, CurTxBufAddr=0x50,
255 };
256 
257 /* Bits in the NetworkConfig register. */
258 enum rx_mode_bits {
259 	AcceptErr=0x80,
260 	RxAcceptBroadcast=0x20, AcceptMulticast=0x10,
261 	RxAcceptAllPhys=0x08, AcceptMyPhys=0x02,
262 };
263 
264 enum mii_reg_bits {
265 	MDIO_ShiftClk=0x10000, MDIO_DataIn=0x80000, MDIO_DataOut=0x20000,
266 	MDIO_EnbOutput=0x40000, MDIO_EnbIn = 0x00000,
267 };
268 
269 /* The Tulip Rx and Tx buffer descriptors. */
270 struct w840_rx_desc {
271 	s32 status;
272 	s32 length;
273 	u32 buffer1;
274 	u32 buffer2;
275 };
276 
277 struct w840_tx_desc {
278 	s32 status;
279 	s32 length;
280 	u32 buffer1, buffer2;
281 };
282 
283 #define MII_CNT		1 /* winbond only supports one MII */
284 struct netdev_private {
285 	struct w840_rx_desc *rx_ring;
286 	dma_addr_t	rx_addr[RX_RING_SIZE];
287 	struct w840_tx_desc *tx_ring;
288 	dma_addr_t	tx_addr[TX_RING_SIZE];
289 	dma_addr_t ring_dma_addr;
290 	/* The addresses of receive-in-place skbuffs. */
291 	struct sk_buff* rx_skbuff[RX_RING_SIZE];
292 	/* The saved address of a sent-in-place packet/buffer, for later free(). */
293 	struct sk_buff* tx_skbuff[TX_RING_SIZE];
294 	struct net_device_stats stats;
295 	struct timer_list timer;	/* Media monitoring timer. */
296 	/* Frequently used values: keep some adjacent for cache effect. */
297 	spinlock_t lock;
298 	int chip_id, drv_flags;
299 	struct pci_dev *pci_dev;
300 	int csr6;
301 	struct w840_rx_desc *rx_head_desc;
302 	unsigned int cur_rx, dirty_rx;		/* Producer/consumer ring indices */
303 	unsigned int rx_buf_sz;				/* Based on MTU+slack. */
304 	unsigned int cur_tx, dirty_tx;
305 	unsigned int tx_q_bytes;
306 	unsigned int tx_full;				/* The Tx queue is full. */
307 	/* MII transceiver section. */
308 	int mii_cnt;						/* MII device addresses. */
309 	unsigned char phys[MII_CNT];		/* MII device addresses, but only the first is used */
310 	u32 mii;
311 	struct mii_if_info mii_if;
312 	void __iomem *base_addr;
313 };
314 
315 static int  eeprom_read(void __iomem *ioaddr, int location);
316 static int  mdio_read(struct net_device *dev, int phy_id, int location);
317 static void mdio_write(struct net_device *dev, int phy_id, int location, int value);
318 static int  netdev_open(struct net_device *dev);
319 static int  update_link(struct net_device *dev);
320 static void netdev_timer(struct timer_list *t);
321 static void init_rxtx_rings(struct net_device *dev);
322 static void free_rxtx_rings(struct netdev_private *np);
323 static void init_registers(struct net_device *dev);
324 static void tx_timeout(struct net_device *dev, unsigned int txqueue);
325 static int alloc_ringdesc(struct net_device *dev);
326 static void free_ringdesc(struct netdev_private *np);
327 static netdev_tx_t start_tx(struct sk_buff *skb, struct net_device *dev);
328 static irqreturn_t intr_handler(int irq, void *dev_instance);
329 static void netdev_error(struct net_device *dev, int intr_status);
330 static int  netdev_rx(struct net_device *dev);
331 static u32 __set_rx_mode(struct net_device *dev);
332 static void set_rx_mode(struct net_device *dev);
333 static struct net_device_stats *get_stats(struct net_device *dev);
334 static int netdev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
335 static const struct ethtool_ops netdev_ethtool_ops;
336 static int  netdev_close(struct net_device *dev);
337 
338 static const struct net_device_ops netdev_ops = {
339 	.ndo_open		= netdev_open,
340 	.ndo_stop		= netdev_close,
341 	.ndo_start_xmit		= start_tx,
342 	.ndo_get_stats		= get_stats,
343 	.ndo_set_rx_mode	= set_rx_mode,
344 	.ndo_do_ioctl		= netdev_ioctl,
345 	.ndo_tx_timeout		= tx_timeout,
346 	.ndo_set_mac_address	= eth_mac_addr,
347 	.ndo_validate_addr	= eth_validate_addr,
348 };
349 
350 static int w840_probe1(struct pci_dev *pdev, const struct pci_device_id *ent)
351 {
352 	struct net_device *dev;
353 	struct netdev_private *np;
354 	static int find_cnt;
355 	int chip_idx = ent->driver_data;
356 	int irq;
357 	int i, option = find_cnt < MAX_UNITS ? options[find_cnt] : 0;
358 	void __iomem *ioaddr;
359 
360 	i = pci_enable_device(pdev);
361 	if (i) return i;
362 
363 	pci_set_master(pdev);
364 
365 	irq = pdev->irq;
366 
367 	if (dma_set_mask(&pdev->dev, DMA_BIT_MASK(32))) {
368 		pr_warn("Device %s disabled due to DMA limitations\n",
369 			pci_name(pdev));
370 		return -EIO;
371 	}
372 	dev = alloc_etherdev(sizeof(*np));
373 	if (!dev)
374 		return -ENOMEM;
375 	SET_NETDEV_DEV(dev, &pdev->dev);
376 
377 	if (pci_request_regions(pdev, DRV_NAME))
378 		goto err_out_netdev;
379 
380 	ioaddr = pci_iomap(pdev, TULIP_BAR, netdev_res_size);
381 	if (!ioaddr)
382 		goto err_out_free_res;
383 
384 	for (i = 0; i < 3; i++)
385 		((__le16 *)dev->dev_addr)[i] = cpu_to_le16(eeprom_read(ioaddr, i));
386 
387 	/* Reset the chip to erase previous misconfiguration.
388 	   No hold time required! */
389 	iowrite32(0x00000001, ioaddr + PCIBusCfg);
390 
391 	np = netdev_priv(dev);
392 	np->pci_dev = pdev;
393 	np->chip_id = chip_idx;
394 	np->drv_flags = pci_id_tbl[chip_idx].drv_flags;
395 	spin_lock_init(&np->lock);
396 	np->mii_if.dev = dev;
397 	np->mii_if.mdio_read = mdio_read;
398 	np->mii_if.mdio_write = mdio_write;
399 	np->base_addr = ioaddr;
400 
401 	pci_set_drvdata(pdev, dev);
402 
403 	if (dev->mem_start)
404 		option = dev->mem_start;
405 
406 	/* The lower four bits are the media type. */
407 	if (option > 0) {
408 		if (option & 0x200)
409 			np->mii_if.full_duplex = 1;
410 		if (option & 15)
411 			dev_info(&dev->dev,
412 				 "ignoring user supplied media type %d",
413 				 option & 15);
414 	}
415 	if (find_cnt < MAX_UNITS  &&  full_duplex[find_cnt] > 0)
416 		np->mii_if.full_duplex = 1;
417 
418 	if (np->mii_if.full_duplex)
419 		np->mii_if.force_media = 1;
420 
421 	/* The chip-specific entries in the device structure. */
422 	dev->netdev_ops = &netdev_ops;
423 	dev->ethtool_ops = &netdev_ethtool_ops;
424 	dev->watchdog_timeo = TX_TIMEOUT;
425 
426 	i = register_netdev(dev);
427 	if (i)
428 		goto err_out_cleardev;
429 
430 	dev_info(&dev->dev, "%s at %p, %pM, IRQ %d\n",
431 		 pci_id_tbl[chip_idx].name, ioaddr, dev->dev_addr, irq);
432 
433 	if (np->drv_flags & CanHaveMII) {
434 		int phy, phy_idx = 0;
435 		for (phy = 1; phy < 32 && phy_idx < MII_CNT; phy++) {
436 			int mii_status = mdio_read(dev, phy, MII_BMSR);
437 			if (mii_status != 0xffff  &&  mii_status != 0x0000) {
438 				np->phys[phy_idx++] = phy;
439 				np->mii_if.advertising = mdio_read(dev, phy, MII_ADVERTISE);
440 				np->mii = (mdio_read(dev, phy, MII_PHYSID1) << 16)+
441 						mdio_read(dev, phy, MII_PHYSID2);
442 				dev_info(&dev->dev,
443 					 "MII PHY %08xh found at address %d, status 0x%04x advertising %04x\n",
444 					 np->mii, phy, mii_status,
445 					 np->mii_if.advertising);
446 			}
447 		}
448 		np->mii_cnt = phy_idx;
449 		np->mii_if.phy_id = np->phys[0];
450 		if (phy_idx == 0) {
451 			dev_warn(&dev->dev,
452 				 "MII PHY not found -- this device may not operate correctly\n");
453 		}
454 	}
455 
456 	find_cnt++;
457 	return 0;
458 
459 err_out_cleardev:
460 	pci_iounmap(pdev, ioaddr);
461 err_out_free_res:
462 	pci_release_regions(pdev);
463 err_out_netdev:
464 	free_netdev (dev);
465 	return -ENODEV;
466 }
467 
468 
469 /* Read the EEPROM and MII Management Data I/O (MDIO) interfaces.  These are
470    often serial bit streams generated by the host processor.
471    The example below is for the common 93c46 EEPROM, 64 16 bit words. */
472 
473 /* Delay between EEPROM clock transitions.
474    No extra delay is needed with 33Mhz PCI, but future 66Mhz access may need
475    a delay.  Note that pre-2.0.34 kernels had a cache-alignment bug that
476    made udelay() unreliable.
477    The old method of using an ISA access as a delay, __SLOW_DOWN_IO__, is
478    deprecated.
479 */
480 #define eeprom_delay(ee_addr)	ioread32(ee_addr)
481 
482 enum EEPROM_Ctrl_Bits {
483 	EE_ShiftClk=0x02, EE_Write0=0x801, EE_Write1=0x805,
484 	EE_ChipSelect=0x801, EE_DataIn=0x08,
485 };
486 
487 /* The EEPROM commands include the alway-set leading bit. */
488 enum EEPROM_Cmds {
489 	EE_WriteCmd=(5 << 6), EE_ReadCmd=(6 << 6), EE_EraseCmd=(7 << 6),
490 };
491 
492 static int eeprom_read(void __iomem *addr, int location)
493 {
494 	int i;
495 	int retval = 0;
496 	void __iomem *ee_addr = addr + EECtrl;
497 	int read_cmd = location | EE_ReadCmd;
498 	iowrite32(EE_ChipSelect, ee_addr);
499 
500 	/* Shift the read command bits out. */
501 	for (i = 10; i >= 0; i--) {
502 		short dataval = (read_cmd & (1 << i)) ? EE_Write1 : EE_Write0;
503 		iowrite32(dataval, ee_addr);
504 		eeprom_delay(ee_addr);
505 		iowrite32(dataval | EE_ShiftClk, ee_addr);
506 		eeprom_delay(ee_addr);
507 	}
508 	iowrite32(EE_ChipSelect, ee_addr);
509 	eeprom_delay(ee_addr);
510 
511 	for (i = 16; i > 0; i--) {
512 		iowrite32(EE_ChipSelect | EE_ShiftClk, ee_addr);
513 		eeprom_delay(ee_addr);
514 		retval = (retval << 1) | ((ioread32(ee_addr) & EE_DataIn) ? 1 : 0);
515 		iowrite32(EE_ChipSelect, ee_addr);
516 		eeprom_delay(ee_addr);
517 	}
518 
519 	/* Terminate the EEPROM access. */
520 	iowrite32(0, ee_addr);
521 	return retval;
522 }
523 
524 /*  MII transceiver control section.
525 	Read and write the MII registers using software-generated serial
526 	MDIO protocol.  See the MII specifications or DP83840A data sheet
527 	for details.
528 
529 	The maximum data clock rate is 2.5 Mhz.  The minimum timing is usually
530 	met by back-to-back 33Mhz PCI cycles. */
531 #define mdio_delay(mdio_addr) ioread32(mdio_addr)
532 
533 /* Set iff a MII transceiver on any interface requires mdio preamble.
534    This only set with older transceivers, so the extra
535    code size of a per-interface flag is not worthwhile. */
536 static char mii_preamble_required = 1;
537 
538 #define MDIO_WRITE0 (MDIO_EnbOutput)
539 #define MDIO_WRITE1 (MDIO_DataOut | MDIO_EnbOutput)
540 
541 /* Generate the preamble required for initial synchronization and
542    a few older transceivers. */
543 static void mdio_sync(void __iomem *mdio_addr)
544 {
545 	int bits = 32;
546 
547 	/* Establish sync by sending at least 32 logic ones. */
548 	while (--bits >= 0) {
549 		iowrite32(MDIO_WRITE1, mdio_addr);
550 		mdio_delay(mdio_addr);
551 		iowrite32(MDIO_WRITE1 | MDIO_ShiftClk, mdio_addr);
552 		mdio_delay(mdio_addr);
553 	}
554 }
555 
556 static int mdio_read(struct net_device *dev, int phy_id, int location)
557 {
558 	struct netdev_private *np = netdev_priv(dev);
559 	void __iomem *mdio_addr = np->base_addr + MIICtrl;
560 	int mii_cmd = (0xf6 << 10) | (phy_id << 5) | location;
561 	int i, retval = 0;
562 
563 	if (mii_preamble_required)
564 		mdio_sync(mdio_addr);
565 
566 	/* Shift the read command bits out. */
567 	for (i = 15; i >= 0; i--) {
568 		int dataval = (mii_cmd & (1 << i)) ? MDIO_WRITE1 : MDIO_WRITE0;
569 
570 		iowrite32(dataval, mdio_addr);
571 		mdio_delay(mdio_addr);
572 		iowrite32(dataval | MDIO_ShiftClk, mdio_addr);
573 		mdio_delay(mdio_addr);
574 	}
575 	/* Read the two transition, 16 data, and wire-idle bits. */
576 	for (i = 20; i > 0; i--) {
577 		iowrite32(MDIO_EnbIn, mdio_addr);
578 		mdio_delay(mdio_addr);
579 		retval = (retval << 1) | ((ioread32(mdio_addr) & MDIO_DataIn) ? 1 : 0);
580 		iowrite32(MDIO_EnbIn | MDIO_ShiftClk, mdio_addr);
581 		mdio_delay(mdio_addr);
582 	}
583 	return (retval>>1) & 0xffff;
584 }
585 
586 static void mdio_write(struct net_device *dev, int phy_id, int location, int value)
587 {
588 	struct netdev_private *np = netdev_priv(dev);
589 	void __iomem *mdio_addr = np->base_addr + MIICtrl;
590 	int mii_cmd = (0x5002 << 16) | (phy_id << 23) | (location<<18) | value;
591 	int i;
592 
593 	if (location == 4  &&  phy_id == np->phys[0])
594 		np->mii_if.advertising = value;
595 
596 	if (mii_preamble_required)
597 		mdio_sync(mdio_addr);
598 
599 	/* Shift the command bits out. */
600 	for (i = 31; i >= 0; i--) {
601 		int dataval = (mii_cmd & (1 << i)) ? MDIO_WRITE1 : MDIO_WRITE0;
602 
603 		iowrite32(dataval, mdio_addr);
604 		mdio_delay(mdio_addr);
605 		iowrite32(dataval | MDIO_ShiftClk, mdio_addr);
606 		mdio_delay(mdio_addr);
607 	}
608 	/* Clear out extra bits. */
609 	for (i = 2; i > 0; i--) {
610 		iowrite32(MDIO_EnbIn, mdio_addr);
611 		mdio_delay(mdio_addr);
612 		iowrite32(MDIO_EnbIn | MDIO_ShiftClk, mdio_addr);
613 		mdio_delay(mdio_addr);
614 	}
615 }
616 
617 
618 static int netdev_open(struct net_device *dev)
619 {
620 	struct netdev_private *np = netdev_priv(dev);
621 	void __iomem *ioaddr = np->base_addr;
622 	const int irq = np->pci_dev->irq;
623 	int i;
624 
625 	iowrite32(0x00000001, ioaddr + PCIBusCfg);		/* Reset */
626 
627 	netif_device_detach(dev);
628 	i = request_irq(irq, intr_handler, IRQF_SHARED, dev->name, dev);
629 	if (i)
630 		goto out_err;
631 
632 	if (debug > 1)
633 		netdev_dbg(dev, "%s() irq %d\n", __func__, irq);
634 
635 	i = alloc_ringdesc(dev);
636 	if (i)
637 		goto out_err;
638 
639 	spin_lock_irq(&np->lock);
640 	netif_device_attach(dev);
641 	init_registers(dev);
642 	spin_unlock_irq(&np->lock);
643 
644 	netif_start_queue(dev);
645 	if (debug > 2)
646 		netdev_dbg(dev, "Done %s()\n", __func__);
647 
648 	/* Set the timer to check for link beat. */
649 	timer_setup(&np->timer, netdev_timer, 0);
650 	np->timer.expires = jiffies + 1*HZ;
651 	add_timer(&np->timer);
652 	return 0;
653 out_err:
654 	netif_device_attach(dev);
655 	return i;
656 }
657 
658 #define MII_DAVICOM_DM9101	0x0181b800
659 
660 static int update_link(struct net_device *dev)
661 {
662 	struct netdev_private *np = netdev_priv(dev);
663 	int duplex, fasteth, result, mii_reg;
664 
665 	/* BSMR */
666 	mii_reg = mdio_read(dev, np->phys[0], MII_BMSR);
667 
668 	if (mii_reg == 0xffff)
669 		return np->csr6;
670 	/* reread: the link status bit is sticky */
671 	mii_reg = mdio_read(dev, np->phys[0], MII_BMSR);
672 	if (!(mii_reg & 0x4)) {
673 		if (netif_carrier_ok(dev)) {
674 			if (debug)
675 				dev_info(&dev->dev,
676 					 "MII #%d reports no link. Disabling watchdog\n",
677 					 np->phys[0]);
678 			netif_carrier_off(dev);
679 		}
680 		return np->csr6;
681 	}
682 	if (!netif_carrier_ok(dev)) {
683 		if (debug)
684 			dev_info(&dev->dev,
685 				 "MII #%d link is back. Enabling watchdog\n",
686 				 np->phys[0]);
687 		netif_carrier_on(dev);
688 	}
689 
690 	if ((np->mii & ~0xf) == MII_DAVICOM_DM9101) {
691 		/* If the link partner doesn't support autonegotiation
692 		 * the MII detects it's abilities with the "parallel detection".
693 		 * Some MIIs update the LPA register to the result of the parallel
694 		 * detection, some don't.
695 		 * The Davicom PHY [at least 0181b800] doesn't.
696 		 * Instead bit 9 and 13 of the BMCR are updated to the result
697 		 * of the negotiation..
698 		 */
699 		mii_reg = mdio_read(dev, np->phys[0], MII_BMCR);
700 		duplex = mii_reg & BMCR_FULLDPLX;
701 		fasteth = mii_reg & BMCR_SPEED100;
702 	} else {
703 		int negotiated;
704 		mii_reg	= mdio_read(dev, np->phys[0], MII_LPA);
705 		negotiated = mii_reg & np->mii_if.advertising;
706 
707 		duplex = (negotiated & LPA_100FULL) || ((negotiated & 0x02C0) == LPA_10FULL);
708 		fasteth = negotiated & 0x380;
709 	}
710 	duplex |= np->mii_if.force_media;
711 	/* remove fastether and fullduplex */
712 	result = np->csr6 & ~0x20000200;
713 	if (duplex)
714 		result |= 0x200;
715 	if (fasteth)
716 		result |= 0x20000000;
717 	if (result != np->csr6 && debug)
718 		dev_info(&dev->dev,
719 			 "Setting %dMBit-%s-duplex based on MII#%d\n",
720 			 fasteth ? 100 : 10, duplex ? "full" : "half",
721 			 np->phys[0]);
722 	return result;
723 }
724 
725 #define RXTX_TIMEOUT	2000
726 static inline void update_csr6(struct net_device *dev, int new)
727 {
728 	struct netdev_private *np = netdev_priv(dev);
729 	void __iomem *ioaddr = np->base_addr;
730 	int limit = RXTX_TIMEOUT;
731 
732 	if (!netif_device_present(dev))
733 		new = 0;
734 	if (new==np->csr6)
735 		return;
736 	/* stop both Tx and Rx processes */
737 	iowrite32(np->csr6 & ~0x2002, ioaddr + NetworkConfig);
738 	/* wait until they have really stopped */
739 	for (;;) {
740 		int csr5 = ioread32(ioaddr + IntrStatus);
741 		int t;
742 
743 		t = (csr5 >> 17) & 0x07;
744 		if (t==0||t==1) {
745 			/* rx stopped */
746 			t = (csr5 >> 20) & 0x07;
747 			if (t==0||t==1)
748 				break;
749 		}
750 
751 		limit--;
752 		if(!limit) {
753 			dev_info(&dev->dev,
754 				 "couldn't stop rxtx, IntrStatus %xh\n", csr5);
755 			break;
756 		}
757 		udelay(1);
758 	}
759 	np->csr6 = new;
760 	/* and restart them with the new configuration */
761 	iowrite32(np->csr6, ioaddr + NetworkConfig);
762 	if (new & 0x200)
763 		np->mii_if.full_duplex = 1;
764 }
765 
766 static void netdev_timer(struct timer_list *t)
767 {
768 	struct netdev_private *np = from_timer(np, t, timer);
769 	struct net_device *dev = pci_get_drvdata(np->pci_dev);
770 	void __iomem *ioaddr = np->base_addr;
771 
772 	if (debug > 2)
773 		netdev_dbg(dev, "Media selection timer tick, status %08x config %08x\n",
774 			   ioread32(ioaddr + IntrStatus),
775 			   ioread32(ioaddr + NetworkConfig));
776 	spin_lock_irq(&np->lock);
777 	update_csr6(dev, update_link(dev));
778 	spin_unlock_irq(&np->lock);
779 	np->timer.expires = jiffies + 10*HZ;
780 	add_timer(&np->timer);
781 }
782 
783 static void init_rxtx_rings(struct net_device *dev)
784 {
785 	struct netdev_private *np = netdev_priv(dev);
786 	int i;
787 
788 	np->rx_head_desc = &np->rx_ring[0];
789 	np->tx_ring = (struct w840_tx_desc*)&np->rx_ring[RX_RING_SIZE];
790 
791 	/* Initial all Rx descriptors. */
792 	for (i = 0; i < RX_RING_SIZE; i++) {
793 		np->rx_ring[i].length = np->rx_buf_sz;
794 		np->rx_ring[i].status = 0;
795 		np->rx_skbuff[i] = NULL;
796 	}
797 	/* Mark the last entry as wrapping the ring. */
798 	np->rx_ring[i-1].length |= DescEndRing;
799 
800 	/* Fill in the Rx buffers.  Handle allocation failure gracefully. */
801 	for (i = 0; i < RX_RING_SIZE; i++) {
802 		struct sk_buff *skb = netdev_alloc_skb(dev, np->rx_buf_sz);
803 		np->rx_skbuff[i] = skb;
804 		if (skb == NULL)
805 			break;
806 		np->rx_addr[i] = dma_map_single(&np->pci_dev->dev, skb->data,
807 						np->rx_buf_sz,
808 						DMA_FROM_DEVICE);
809 
810 		np->rx_ring[i].buffer1 = np->rx_addr[i];
811 		np->rx_ring[i].status = DescOwned;
812 	}
813 
814 	np->cur_rx = 0;
815 	np->dirty_rx = (unsigned int)(i - RX_RING_SIZE);
816 
817 	/* Initialize the Tx descriptors */
818 	for (i = 0; i < TX_RING_SIZE; i++) {
819 		np->tx_skbuff[i] = NULL;
820 		np->tx_ring[i].status = 0;
821 	}
822 	np->tx_full = 0;
823 	np->tx_q_bytes = np->dirty_tx = np->cur_tx = 0;
824 
825 	iowrite32(np->ring_dma_addr, np->base_addr + RxRingPtr);
826 	iowrite32(np->ring_dma_addr+sizeof(struct w840_rx_desc)*RX_RING_SIZE,
827 		np->base_addr + TxRingPtr);
828 
829 }
830 
831 static void free_rxtx_rings(struct netdev_private* np)
832 {
833 	int i;
834 	/* Free all the skbuffs in the Rx queue. */
835 	for (i = 0; i < RX_RING_SIZE; i++) {
836 		np->rx_ring[i].status = 0;
837 		if (np->rx_skbuff[i]) {
838 			dma_unmap_single(&np->pci_dev->dev, np->rx_addr[i],
839 					 np->rx_skbuff[i]->len,
840 					 DMA_FROM_DEVICE);
841 			dev_kfree_skb(np->rx_skbuff[i]);
842 		}
843 		np->rx_skbuff[i] = NULL;
844 	}
845 	for (i = 0; i < TX_RING_SIZE; i++) {
846 		if (np->tx_skbuff[i]) {
847 			dma_unmap_single(&np->pci_dev->dev, np->tx_addr[i],
848 					 np->tx_skbuff[i]->len, DMA_TO_DEVICE);
849 			dev_kfree_skb(np->tx_skbuff[i]);
850 		}
851 		np->tx_skbuff[i] = NULL;
852 	}
853 }
854 
855 static void init_registers(struct net_device *dev)
856 {
857 	struct netdev_private *np = netdev_priv(dev);
858 	void __iomem *ioaddr = np->base_addr;
859 	int i;
860 
861 	for (i = 0; i < 6; i++)
862 		iowrite8(dev->dev_addr[i], ioaddr + StationAddr + i);
863 
864 	/* Initialize other registers. */
865 #ifdef __BIG_ENDIAN
866 	i = (1<<20);	/* Big-endian descriptors */
867 #else
868 	i = 0;
869 #endif
870 	i |= (0x04<<2);		/* skip length 4 u32 */
871 	i |= 0x02;		/* give Rx priority */
872 
873 	/* Configure the PCI bus bursts and FIFO thresholds.
874 	   486: Set 8 longword cache alignment, 8 longword burst.
875 	   586: Set 16 longword cache alignment, no burst limit.
876 	   Cache alignment bits 15:14	     Burst length 13:8
877 		0000	<not allowed> 		0000 align to cache	0800 8 longwords
878 		4000	8  longwords		0100 1 longword		1000 16 longwords
879 		8000	16 longwords		0200 2 longwords	2000 32 longwords
880 		C000	32  longwords		0400 4 longwords */
881 
882 #if defined (__i386__) && !defined(MODULE)
883 	/* When not a module we can work around broken '486 PCI boards. */
884 	if (boot_cpu_data.x86 <= 4) {
885 		i |= 0x4800;
886 		dev_info(&dev->dev,
887 			 "This is a 386/486 PCI system, setting cache alignment to 8 longwords\n");
888 	} else {
889 		i |= 0xE000;
890 	}
891 #elif defined(__powerpc__) || defined(__i386__) || defined(__alpha__) || defined(__ia64__) || defined(__x86_64__)
892 	i |= 0xE000;
893 #elif defined(CONFIG_SPARC) || defined (CONFIG_PARISC) || defined(CONFIG_ARM)
894 	i |= 0x4800;
895 #else
896 	dev_warn(&dev->dev, "unknown CPU architecture, using default csr0 setting\n");
897 	i |= 0x4800;
898 #endif
899 	iowrite32(i, ioaddr + PCIBusCfg);
900 
901 	np->csr6 = 0;
902 	/* 128 byte Tx threshold;
903 		Transmit on; Receive on; */
904 	update_csr6(dev, 0x00022002 | update_link(dev) | __set_rx_mode(dev));
905 
906 	/* Clear and Enable interrupts by setting the interrupt mask. */
907 	iowrite32(0x1A0F5, ioaddr + IntrStatus);
908 	iowrite32(0x1A0F5, ioaddr + IntrEnable);
909 
910 	iowrite32(0, ioaddr + RxStartDemand);
911 }
912 
913 static void tx_timeout(struct net_device *dev, unsigned int txqueue)
914 {
915 	struct netdev_private *np = netdev_priv(dev);
916 	void __iomem *ioaddr = np->base_addr;
917 	const int irq = np->pci_dev->irq;
918 
919 	dev_warn(&dev->dev, "Transmit timed out, status %08x, resetting...\n",
920 		 ioread32(ioaddr + IntrStatus));
921 
922 	{
923 		int i;
924 		printk(KERN_DEBUG "  Rx ring %p: ", np->rx_ring);
925 		for (i = 0; i < RX_RING_SIZE; i++)
926 			printk(KERN_CONT " %08x", (unsigned int)np->rx_ring[i].status);
927 		printk(KERN_CONT "\n");
928 		printk(KERN_DEBUG "  Tx ring %p: ", np->tx_ring);
929 		for (i = 0; i < TX_RING_SIZE; i++)
930 			printk(KERN_CONT " %08x", np->tx_ring[i].status);
931 		printk(KERN_CONT "\n");
932 	}
933 	printk(KERN_DEBUG "Tx cur %d Tx dirty %d Tx Full %d, q bytes %d\n",
934 	       np->cur_tx, np->dirty_tx, np->tx_full, np->tx_q_bytes);
935 	printk(KERN_DEBUG "Tx Descriptor addr %xh\n", ioread32(ioaddr+0x4C));
936 
937 	disable_irq(irq);
938 	spin_lock_irq(&np->lock);
939 	/*
940 	 * Under high load dirty_tx and the internal tx descriptor pointer
941 	 * come out of sync, thus perform a software reset and reinitialize
942 	 * everything.
943 	 */
944 
945 	iowrite32(1, np->base_addr+PCIBusCfg);
946 	udelay(1);
947 
948 	free_rxtx_rings(np);
949 	init_rxtx_rings(dev);
950 	init_registers(dev);
951 	spin_unlock_irq(&np->lock);
952 	enable_irq(irq);
953 
954 	netif_wake_queue(dev);
955 	netif_trans_update(dev); /* prevent tx timeout */
956 	np->stats.tx_errors++;
957 }
958 
959 /* Initialize the Rx and Tx rings, along with various 'dev' bits. */
960 static int alloc_ringdesc(struct net_device *dev)
961 {
962 	struct netdev_private *np = netdev_priv(dev);
963 
964 	np->rx_buf_sz = (dev->mtu <= 1500 ? PKT_BUF_SZ : dev->mtu + 32);
965 
966 	np->rx_ring = dma_alloc_coherent(&np->pci_dev->dev,
967 					 sizeof(struct w840_rx_desc) * RX_RING_SIZE +
968 					 sizeof(struct w840_tx_desc) * TX_RING_SIZE,
969 					 &np->ring_dma_addr, GFP_KERNEL);
970 	if(!np->rx_ring)
971 		return -ENOMEM;
972 	init_rxtx_rings(dev);
973 	return 0;
974 }
975 
976 static void free_ringdesc(struct netdev_private *np)
977 {
978 	dma_free_coherent(&np->pci_dev->dev,
979 			  sizeof(struct w840_rx_desc) * RX_RING_SIZE +
980 			  sizeof(struct w840_tx_desc) * TX_RING_SIZE,
981 			  np->rx_ring, np->ring_dma_addr);
982 
983 }
984 
985 static netdev_tx_t start_tx(struct sk_buff *skb, struct net_device *dev)
986 {
987 	struct netdev_private *np = netdev_priv(dev);
988 	unsigned entry;
989 
990 	/* Caution: the write order is important here, set the field
991 	   with the "ownership" bits last. */
992 
993 	/* Calculate the next Tx descriptor entry. */
994 	entry = np->cur_tx % TX_RING_SIZE;
995 
996 	np->tx_addr[entry] = dma_map_single(&np->pci_dev->dev, skb->data,
997 					    skb->len, DMA_TO_DEVICE);
998 	np->tx_skbuff[entry] = skb;
999 
1000 	np->tx_ring[entry].buffer1 = np->tx_addr[entry];
1001 	if (skb->len < TX_BUFLIMIT) {
1002 		np->tx_ring[entry].length = DescWholePkt | skb->len;
1003 	} else {
1004 		int len = skb->len - TX_BUFLIMIT;
1005 
1006 		np->tx_ring[entry].buffer2 = np->tx_addr[entry]+TX_BUFLIMIT;
1007 		np->tx_ring[entry].length = DescWholePkt | (len << 11) | TX_BUFLIMIT;
1008 	}
1009 	if(entry == TX_RING_SIZE-1)
1010 		np->tx_ring[entry].length |= DescEndRing;
1011 
1012 	/* Now acquire the irq spinlock.
1013 	 * The difficult race is the ordering between
1014 	 * increasing np->cur_tx and setting DescOwned:
1015 	 * - if np->cur_tx is increased first the interrupt
1016 	 *   handler could consider the packet as transmitted
1017 	 *   since DescOwned is cleared.
1018 	 * - If DescOwned is set first the NIC could report the
1019 	 *   packet as sent, but the interrupt handler would ignore it
1020 	 *   since the np->cur_tx was not yet increased.
1021 	 */
1022 	spin_lock_irq(&np->lock);
1023 	np->cur_tx++;
1024 
1025 	wmb(); /* flush length, buffer1, buffer2 */
1026 	np->tx_ring[entry].status = DescOwned;
1027 	wmb(); /* flush status and kick the hardware */
1028 	iowrite32(0, np->base_addr + TxStartDemand);
1029 	np->tx_q_bytes += skb->len;
1030 	/* Work around horrible bug in the chip by marking the queue as full
1031 	   when we do not have FIFO room for a maximum sized packet. */
1032 	if (np->cur_tx - np->dirty_tx > TX_QUEUE_LEN ||
1033 		((np->drv_flags & HasBrokenTx) && np->tx_q_bytes > TX_BUG_FIFO_LIMIT)) {
1034 		netif_stop_queue(dev);
1035 		wmb();
1036 		np->tx_full = 1;
1037 	}
1038 	spin_unlock_irq(&np->lock);
1039 
1040 	if (debug > 4) {
1041 		netdev_dbg(dev, "Transmit frame #%d queued in slot %d\n",
1042 			   np->cur_tx, entry);
1043 	}
1044 	return NETDEV_TX_OK;
1045 }
1046 
1047 static void netdev_tx_done(struct net_device *dev)
1048 {
1049 	struct netdev_private *np = netdev_priv(dev);
1050 	for (; np->cur_tx - np->dirty_tx > 0; np->dirty_tx++) {
1051 		int entry = np->dirty_tx % TX_RING_SIZE;
1052 		int tx_status = np->tx_ring[entry].status;
1053 
1054 		if (tx_status < 0)
1055 			break;
1056 		if (tx_status & 0x8000) { 	/* There was an error, log it. */
1057 #ifndef final_version
1058 			if (debug > 1)
1059 				netdev_dbg(dev, "Transmit error, Tx status %08x\n",
1060 					   tx_status);
1061 #endif
1062 			np->stats.tx_errors++;
1063 			if (tx_status & 0x0104) np->stats.tx_aborted_errors++;
1064 			if (tx_status & 0x0C80) np->stats.tx_carrier_errors++;
1065 			if (tx_status & 0x0200) np->stats.tx_window_errors++;
1066 			if (tx_status & 0x0002) np->stats.tx_fifo_errors++;
1067 			if ((tx_status & 0x0080) && np->mii_if.full_duplex == 0)
1068 				np->stats.tx_heartbeat_errors++;
1069 		} else {
1070 #ifndef final_version
1071 			if (debug > 3)
1072 				netdev_dbg(dev, "Transmit slot %d ok, Tx status %08x\n",
1073 					   entry, tx_status);
1074 #endif
1075 			np->stats.tx_bytes += np->tx_skbuff[entry]->len;
1076 			np->stats.collisions += (tx_status >> 3) & 15;
1077 			np->stats.tx_packets++;
1078 		}
1079 		/* Free the original skb. */
1080 		dma_unmap_single(&np->pci_dev->dev, np->tx_addr[entry],
1081 				 np->tx_skbuff[entry]->len, DMA_TO_DEVICE);
1082 		np->tx_q_bytes -= np->tx_skbuff[entry]->len;
1083 		dev_kfree_skb_irq(np->tx_skbuff[entry]);
1084 		np->tx_skbuff[entry] = NULL;
1085 	}
1086 	if (np->tx_full &&
1087 		np->cur_tx - np->dirty_tx < TX_QUEUE_LEN_RESTART &&
1088 		np->tx_q_bytes < TX_BUG_FIFO_LIMIT) {
1089 		/* The ring is no longer full, clear tbusy. */
1090 		np->tx_full = 0;
1091 		wmb();
1092 		netif_wake_queue(dev);
1093 	}
1094 }
1095 
1096 /* The interrupt handler does all of the Rx thread work and cleans up
1097    after the Tx thread. */
1098 static irqreturn_t intr_handler(int irq, void *dev_instance)
1099 {
1100 	struct net_device *dev = (struct net_device *)dev_instance;
1101 	struct netdev_private *np = netdev_priv(dev);
1102 	void __iomem *ioaddr = np->base_addr;
1103 	int work_limit = max_interrupt_work;
1104 	int handled = 0;
1105 
1106 	if (!netif_device_present(dev))
1107 		return IRQ_NONE;
1108 	do {
1109 		u32 intr_status = ioread32(ioaddr + IntrStatus);
1110 
1111 		/* Acknowledge all of the current interrupt sources ASAP. */
1112 		iowrite32(intr_status & 0x001ffff, ioaddr + IntrStatus);
1113 
1114 		if (debug > 4)
1115 			netdev_dbg(dev, "Interrupt, status %04x\n", intr_status);
1116 
1117 		if ((intr_status & (NormalIntr|AbnormalIntr)) == 0)
1118 			break;
1119 
1120 		handled = 1;
1121 
1122 		if (intr_status & (RxIntr | RxNoBuf))
1123 			netdev_rx(dev);
1124 		if (intr_status & RxNoBuf)
1125 			iowrite32(0, ioaddr + RxStartDemand);
1126 
1127 		if (intr_status & (TxNoBuf | TxIntr) &&
1128 			np->cur_tx != np->dirty_tx) {
1129 			spin_lock(&np->lock);
1130 			netdev_tx_done(dev);
1131 			spin_unlock(&np->lock);
1132 		}
1133 
1134 		/* Abnormal error summary/uncommon events handlers. */
1135 		if (intr_status & (AbnormalIntr | TxFIFOUnderflow | SystemError |
1136 						   TimerInt | TxDied))
1137 			netdev_error(dev, intr_status);
1138 
1139 		if (--work_limit < 0) {
1140 			dev_warn(&dev->dev,
1141 				 "Too much work at interrupt, status=0x%04x\n",
1142 				 intr_status);
1143 			/* Set the timer to re-enable the other interrupts after
1144 			   10*82usec ticks. */
1145 			spin_lock(&np->lock);
1146 			if (netif_device_present(dev)) {
1147 				iowrite32(AbnormalIntr | TimerInt, ioaddr + IntrEnable);
1148 				iowrite32(10, ioaddr + GPTimer);
1149 			}
1150 			spin_unlock(&np->lock);
1151 			break;
1152 		}
1153 	} while (1);
1154 
1155 	if (debug > 3)
1156 		netdev_dbg(dev, "exiting interrupt, status=%#4.4x\n",
1157 			   ioread32(ioaddr + IntrStatus));
1158 	return IRQ_RETVAL(handled);
1159 }
1160 
1161 /* This routine is logically part of the interrupt handler, but separated
1162    for clarity and better register allocation. */
1163 static int netdev_rx(struct net_device *dev)
1164 {
1165 	struct netdev_private *np = netdev_priv(dev);
1166 	int entry = np->cur_rx % RX_RING_SIZE;
1167 	int work_limit = np->dirty_rx + RX_RING_SIZE - np->cur_rx;
1168 
1169 	if (debug > 4) {
1170 		netdev_dbg(dev, " In netdev_rx(), entry %d status %04x\n",
1171 			   entry, np->rx_ring[entry].status);
1172 	}
1173 
1174 	/* If EOP is set on the next entry, it's a new packet. Send it up. */
1175 	while (--work_limit >= 0) {
1176 		struct w840_rx_desc *desc = np->rx_head_desc;
1177 		s32 status = desc->status;
1178 
1179 		if (debug > 4)
1180 			netdev_dbg(dev, "  netdev_rx() status was %08x\n",
1181 				   status);
1182 		if (status < 0)
1183 			break;
1184 		if ((status & 0x38008300) != 0x0300) {
1185 			if ((status & 0x38000300) != 0x0300) {
1186 				/* Ingore earlier buffers. */
1187 				if ((status & 0xffff) != 0x7fff) {
1188 					dev_warn(&dev->dev,
1189 						 "Oversized Ethernet frame spanned multiple buffers, entry %#x status %04x!\n",
1190 						 np->cur_rx, status);
1191 					np->stats.rx_length_errors++;
1192 				}
1193 			} else if (status & 0x8000) {
1194 				/* There was a fatal error. */
1195 				if (debug > 2)
1196 					netdev_dbg(dev, "Receive error, Rx status %08x\n",
1197 						   status);
1198 				np->stats.rx_errors++; /* end of a packet.*/
1199 				if (status & 0x0890) np->stats.rx_length_errors++;
1200 				if (status & 0x004C) np->stats.rx_frame_errors++;
1201 				if (status & 0x0002) np->stats.rx_crc_errors++;
1202 			}
1203 		} else {
1204 			struct sk_buff *skb;
1205 			/* Omit the four octet CRC from the length. */
1206 			int pkt_len = ((status >> 16) & 0x7ff) - 4;
1207 
1208 #ifndef final_version
1209 			if (debug > 4)
1210 				netdev_dbg(dev, "  netdev_rx() normal Rx pkt length %d status %x\n",
1211 					   pkt_len, status);
1212 #endif
1213 			/* Check if the packet is long enough to accept without copying
1214 			   to a minimally-sized skbuff. */
1215 			if (pkt_len < rx_copybreak &&
1216 			    (skb = netdev_alloc_skb(dev, pkt_len + 2)) != NULL) {
1217 				skb_reserve(skb, 2);	/* 16 byte align the IP header */
1218 				dma_sync_single_for_cpu(&np->pci_dev->dev,
1219 							np->rx_addr[entry],
1220 							np->rx_skbuff[entry]->len,
1221 							DMA_FROM_DEVICE);
1222 				skb_copy_to_linear_data(skb, np->rx_skbuff[entry]->data, pkt_len);
1223 				skb_put(skb, pkt_len);
1224 				dma_sync_single_for_device(&np->pci_dev->dev,
1225 							   np->rx_addr[entry],
1226 							   np->rx_skbuff[entry]->len,
1227 							   DMA_FROM_DEVICE);
1228 			} else {
1229 				dma_unmap_single(&np->pci_dev->dev,
1230 						 np->rx_addr[entry],
1231 						 np->rx_skbuff[entry]->len,
1232 						 DMA_FROM_DEVICE);
1233 				skb_put(skb = np->rx_skbuff[entry], pkt_len);
1234 				np->rx_skbuff[entry] = NULL;
1235 			}
1236 #ifndef final_version				/* Remove after testing. */
1237 			/* You will want this info for the initial debug. */
1238 			if (debug > 5)
1239 				netdev_dbg(dev, "  Rx data %pM %pM %02x%02x %pI4\n",
1240 					   &skb->data[0], &skb->data[6],
1241 					   skb->data[12], skb->data[13],
1242 					   &skb->data[14]);
1243 #endif
1244 			skb->protocol = eth_type_trans(skb, dev);
1245 			netif_rx(skb);
1246 			np->stats.rx_packets++;
1247 			np->stats.rx_bytes += pkt_len;
1248 		}
1249 		entry = (++np->cur_rx) % RX_RING_SIZE;
1250 		np->rx_head_desc = &np->rx_ring[entry];
1251 	}
1252 
1253 	/* Refill the Rx ring buffers. */
1254 	for (; np->cur_rx - np->dirty_rx > 0; np->dirty_rx++) {
1255 		struct sk_buff *skb;
1256 		entry = np->dirty_rx % RX_RING_SIZE;
1257 		if (np->rx_skbuff[entry] == NULL) {
1258 			skb = netdev_alloc_skb(dev, np->rx_buf_sz);
1259 			np->rx_skbuff[entry] = skb;
1260 			if (skb == NULL)
1261 				break;			/* Better luck next round. */
1262 			np->rx_addr[entry] = dma_map_single(&np->pci_dev->dev,
1263 							    skb->data,
1264 							    np->rx_buf_sz,
1265 							    DMA_FROM_DEVICE);
1266 			np->rx_ring[entry].buffer1 = np->rx_addr[entry];
1267 		}
1268 		wmb();
1269 		np->rx_ring[entry].status = DescOwned;
1270 	}
1271 
1272 	return 0;
1273 }
1274 
1275 static void netdev_error(struct net_device *dev, int intr_status)
1276 {
1277 	struct netdev_private *np = netdev_priv(dev);
1278 	void __iomem *ioaddr = np->base_addr;
1279 
1280 	if (debug > 2)
1281 		netdev_dbg(dev, "Abnormal event, %08x\n", intr_status);
1282 	if (intr_status == 0xffffffff)
1283 		return;
1284 	spin_lock(&np->lock);
1285 	if (intr_status & TxFIFOUnderflow) {
1286 		int new;
1287 		/* Bump up the Tx threshold */
1288 #if 0
1289 		/* This causes lots of dropped packets,
1290 		 * and under high load even tx_timeouts
1291 		 */
1292 		new = np->csr6 + 0x4000;
1293 #else
1294 		new = (np->csr6 >> 14)&0x7f;
1295 		if (new < 64)
1296 			new *= 2;
1297 		 else
1298 		 	new = 127; /* load full packet before starting */
1299 		new = (np->csr6 & ~(0x7F << 14)) | (new<<14);
1300 #endif
1301 		netdev_dbg(dev, "Tx underflow, new csr6 %08x\n", new);
1302 		update_csr6(dev, new);
1303 	}
1304 	if (intr_status & RxDied) {		/* Missed a Rx frame. */
1305 		np->stats.rx_errors++;
1306 	}
1307 	if (intr_status & TimerInt) {
1308 		/* Re-enable other interrupts. */
1309 		if (netif_device_present(dev))
1310 			iowrite32(0x1A0F5, ioaddr + IntrEnable);
1311 	}
1312 	np->stats.rx_missed_errors += ioread32(ioaddr + RxMissed) & 0xffff;
1313 	iowrite32(0, ioaddr + RxStartDemand);
1314 	spin_unlock(&np->lock);
1315 }
1316 
1317 static struct net_device_stats *get_stats(struct net_device *dev)
1318 {
1319 	struct netdev_private *np = netdev_priv(dev);
1320 	void __iomem *ioaddr = np->base_addr;
1321 
1322 	/* The chip only need report frame silently dropped. */
1323 	spin_lock_irq(&np->lock);
1324 	if (netif_running(dev) && netif_device_present(dev))
1325 		np->stats.rx_missed_errors += ioread32(ioaddr + RxMissed) & 0xffff;
1326 	spin_unlock_irq(&np->lock);
1327 
1328 	return &np->stats;
1329 }
1330 
1331 
1332 static u32 __set_rx_mode(struct net_device *dev)
1333 {
1334 	struct netdev_private *np = netdev_priv(dev);
1335 	void __iomem *ioaddr = np->base_addr;
1336 	u32 mc_filter[2];			/* Multicast hash filter */
1337 	u32 rx_mode;
1338 
1339 	if (dev->flags & IFF_PROMISC) {			/* Set promiscuous. */
1340 		memset(mc_filter, 0xff, sizeof(mc_filter));
1341 		rx_mode = RxAcceptBroadcast | AcceptMulticast | RxAcceptAllPhys
1342 			| AcceptMyPhys;
1343 	} else if ((netdev_mc_count(dev) > multicast_filter_limit) ||
1344 		   (dev->flags & IFF_ALLMULTI)) {
1345 		/* Too many to match, or accept all multicasts. */
1346 		memset(mc_filter, 0xff, sizeof(mc_filter));
1347 		rx_mode = RxAcceptBroadcast | AcceptMulticast | AcceptMyPhys;
1348 	} else {
1349 		struct netdev_hw_addr *ha;
1350 
1351 		memset(mc_filter, 0, sizeof(mc_filter));
1352 		netdev_for_each_mc_addr(ha, dev) {
1353 			int filbit;
1354 
1355 			filbit = (ether_crc(ETH_ALEN, ha->addr) >> 26) ^ 0x3F;
1356 			filbit &= 0x3f;
1357 			mc_filter[filbit >> 5] |= 1 << (filbit & 31);
1358 		}
1359 		rx_mode = RxAcceptBroadcast | AcceptMulticast | AcceptMyPhys;
1360 	}
1361 	iowrite32(mc_filter[0], ioaddr + MulticastFilter0);
1362 	iowrite32(mc_filter[1], ioaddr + MulticastFilter1);
1363 	return rx_mode;
1364 }
1365 
1366 static void set_rx_mode(struct net_device *dev)
1367 {
1368 	struct netdev_private *np = netdev_priv(dev);
1369 	u32 rx_mode = __set_rx_mode(dev);
1370 	spin_lock_irq(&np->lock);
1371 	update_csr6(dev, (np->csr6 & ~0x00F8) | rx_mode);
1372 	spin_unlock_irq(&np->lock);
1373 }
1374 
1375 static void netdev_get_drvinfo (struct net_device *dev, struct ethtool_drvinfo *info)
1376 {
1377 	struct netdev_private *np = netdev_priv(dev);
1378 
1379 	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
1380 	strlcpy(info->bus_info, pci_name(np->pci_dev), sizeof(info->bus_info));
1381 }
1382 
1383 static int netdev_get_link_ksettings(struct net_device *dev,
1384 				     struct ethtool_link_ksettings *cmd)
1385 {
1386 	struct netdev_private *np = netdev_priv(dev);
1387 
1388 	spin_lock_irq(&np->lock);
1389 	mii_ethtool_get_link_ksettings(&np->mii_if, cmd);
1390 	spin_unlock_irq(&np->lock);
1391 
1392 	return 0;
1393 }
1394 
1395 static int netdev_set_link_ksettings(struct net_device *dev,
1396 				     const struct ethtool_link_ksettings *cmd)
1397 {
1398 	struct netdev_private *np = netdev_priv(dev);
1399 	int rc;
1400 
1401 	spin_lock_irq(&np->lock);
1402 	rc = mii_ethtool_set_link_ksettings(&np->mii_if, cmd);
1403 	spin_unlock_irq(&np->lock);
1404 
1405 	return rc;
1406 }
1407 
1408 static int netdev_nway_reset(struct net_device *dev)
1409 {
1410 	struct netdev_private *np = netdev_priv(dev);
1411 	return mii_nway_restart(&np->mii_if);
1412 }
1413 
1414 static u32 netdev_get_link(struct net_device *dev)
1415 {
1416 	struct netdev_private *np = netdev_priv(dev);
1417 	return mii_link_ok(&np->mii_if);
1418 }
1419 
1420 static u32 netdev_get_msglevel(struct net_device *dev)
1421 {
1422 	return debug;
1423 }
1424 
1425 static void netdev_set_msglevel(struct net_device *dev, u32 value)
1426 {
1427 	debug = value;
1428 }
1429 
1430 static const struct ethtool_ops netdev_ethtool_ops = {
1431 	.get_drvinfo		= netdev_get_drvinfo,
1432 	.nway_reset		= netdev_nway_reset,
1433 	.get_link		= netdev_get_link,
1434 	.get_msglevel		= netdev_get_msglevel,
1435 	.set_msglevel		= netdev_set_msglevel,
1436 	.get_link_ksettings	= netdev_get_link_ksettings,
1437 	.set_link_ksettings	= netdev_set_link_ksettings,
1438 };
1439 
1440 static int netdev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
1441 {
1442 	struct mii_ioctl_data *data = if_mii(rq);
1443 	struct netdev_private *np = netdev_priv(dev);
1444 
1445 	switch(cmd) {
1446 	case SIOCGMIIPHY:		/* Get address of MII PHY in use. */
1447 		data->phy_id = ((struct netdev_private *)netdev_priv(dev))->phys[0] & 0x1f;
1448 		fallthrough;
1449 
1450 	case SIOCGMIIREG:		/* Read MII PHY register. */
1451 		spin_lock_irq(&np->lock);
1452 		data->val_out = mdio_read(dev, data->phy_id & 0x1f, data->reg_num & 0x1f);
1453 		spin_unlock_irq(&np->lock);
1454 		return 0;
1455 
1456 	case SIOCSMIIREG:		/* Write MII PHY register. */
1457 		spin_lock_irq(&np->lock);
1458 		mdio_write(dev, data->phy_id & 0x1f, data->reg_num & 0x1f, data->val_in);
1459 		spin_unlock_irq(&np->lock);
1460 		return 0;
1461 	default:
1462 		return -EOPNOTSUPP;
1463 	}
1464 }
1465 
1466 static int netdev_close(struct net_device *dev)
1467 {
1468 	struct netdev_private *np = netdev_priv(dev);
1469 	void __iomem *ioaddr = np->base_addr;
1470 
1471 	netif_stop_queue(dev);
1472 
1473 	if (debug > 1) {
1474 		netdev_dbg(dev, "Shutting down ethercard, status was %08x Config %08x\n",
1475 			   ioread32(ioaddr + IntrStatus),
1476 			   ioread32(ioaddr + NetworkConfig));
1477 		netdev_dbg(dev, "Queue pointers were Tx %d / %d,  Rx %d / %d\n",
1478 			   np->cur_tx, np->dirty_tx,
1479 			   np->cur_rx, np->dirty_rx);
1480 	}
1481 
1482  	/* Stop the chip's Tx and Rx processes. */
1483 	spin_lock_irq(&np->lock);
1484 	netif_device_detach(dev);
1485 	update_csr6(dev, 0);
1486 	iowrite32(0x0000, ioaddr + IntrEnable);
1487 	spin_unlock_irq(&np->lock);
1488 
1489 	free_irq(np->pci_dev->irq, dev);
1490 	wmb();
1491 	netif_device_attach(dev);
1492 
1493 	if (ioread32(ioaddr + NetworkConfig) != 0xffffffff)
1494 		np->stats.rx_missed_errors += ioread32(ioaddr + RxMissed) & 0xffff;
1495 
1496 #ifdef __i386__
1497 	if (debug > 2) {
1498 		int i;
1499 
1500 		printk(KERN_DEBUG"  Tx ring at %p:\n", np->tx_ring);
1501 		for (i = 0; i < TX_RING_SIZE; i++)
1502 			printk(KERN_DEBUG " #%d desc. %04x %04x %08x\n",
1503 			       i, np->tx_ring[i].length,
1504 			       np->tx_ring[i].status, np->tx_ring[i].buffer1);
1505 		printk(KERN_DEBUG "  Rx ring %p:\n", np->rx_ring);
1506 		for (i = 0; i < RX_RING_SIZE; i++) {
1507 			printk(KERN_DEBUG " #%d desc. %04x %04x %08x\n",
1508 			       i, np->rx_ring[i].length,
1509 			       np->rx_ring[i].status, np->rx_ring[i].buffer1);
1510 		}
1511 	}
1512 #endif /* __i386__ debugging only */
1513 
1514 	del_timer_sync(&np->timer);
1515 
1516 	free_rxtx_rings(np);
1517 	free_ringdesc(np);
1518 
1519 	return 0;
1520 }
1521 
1522 static void w840_remove1(struct pci_dev *pdev)
1523 {
1524 	struct net_device *dev = pci_get_drvdata(pdev);
1525 
1526 	if (dev) {
1527 		struct netdev_private *np = netdev_priv(dev);
1528 		unregister_netdev(dev);
1529 		pci_release_regions(pdev);
1530 		pci_iounmap(pdev, np->base_addr);
1531 		free_netdev(dev);
1532 	}
1533 }
1534 
1535 /*
1536  * suspend/resume synchronization:
1537  * - open, close, do_ioctl:
1538  * 	rtnl_lock, & netif_device_detach after the rtnl_unlock.
1539  * - get_stats:
1540  * 	spin_lock_irq(np->lock), doesn't touch hw if not present
1541  * - start_xmit:
1542  * 	synchronize_irq + netif_tx_disable;
1543  * - tx_timeout:
1544  * 	netif_device_detach + netif_tx_disable;
1545  * - set_multicast_list
1546  * 	netif_device_detach + netif_tx_disable;
1547  * - interrupt handler
1548  * 	doesn't touch hw if not present, synchronize_irq waits for
1549  * 	running instances of the interrupt handler.
1550  *
1551  * Disabling hw requires clearing csr6 & IntrEnable.
1552  * update_csr6 & all function that write IntrEnable check netif_device_present
1553  * before settings any bits.
1554  *
1555  * Detach must occur under spin_unlock_irq(), interrupts from a detached
1556  * device would cause an irq storm.
1557  */
1558 static int __maybe_unused w840_suspend(struct device *dev_d)
1559 {
1560 	struct net_device *dev = dev_get_drvdata(dev_d);
1561 	struct netdev_private *np = netdev_priv(dev);
1562 	void __iomem *ioaddr = np->base_addr;
1563 
1564 	rtnl_lock();
1565 	if (netif_running (dev)) {
1566 		del_timer_sync(&np->timer);
1567 
1568 		spin_lock_irq(&np->lock);
1569 		netif_device_detach(dev);
1570 		update_csr6(dev, 0);
1571 		iowrite32(0, ioaddr + IntrEnable);
1572 		spin_unlock_irq(&np->lock);
1573 
1574 		synchronize_irq(np->pci_dev->irq);
1575 		netif_tx_disable(dev);
1576 
1577 		np->stats.rx_missed_errors += ioread32(ioaddr + RxMissed) & 0xffff;
1578 
1579 		/* no more hardware accesses behind this line. */
1580 
1581 		BUG_ON(np->csr6 || ioread32(ioaddr + IntrEnable));
1582 
1583 		/* pci_power_off(pdev, -1); */
1584 
1585 		free_rxtx_rings(np);
1586 	} else {
1587 		netif_device_detach(dev);
1588 	}
1589 	rtnl_unlock();
1590 	return 0;
1591 }
1592 
1593 static int __maybe_unused w840_resume(struct device *dev_d)
1594 {
1595 	struct net_device *dev = dev_get_drvdata(dev_d);
1596 	struct netdev_private *np = netdev_priv(dev);
1597 
1598 	rtnl_lock();
1599 	if (netif_device_present(dev))
1600 		goto out; /* device not suspended */
1601 	if (netif_running(dev)) {
1602 		spin_lock_irq(&np->lock);
1603 		iowrite32(1, np->base_addr+PCIBusCfg);
1604 		ioread32(np->base_addr+PCIBusCfg);
1605 		udelay(1);
1606 		netif_device_attach(dev);
1607 		init_rxtx_rings(dev);
1608 		init_registers(dev);
1609 		spin_unlock_irq(&np->lock);
1610 
1611 		netif_wake_queue(dev);
1612 
1613 		mod_timer(&np->timer, jiffies + 1*HZ);
1614 	} else {
1615 		netif_device_attach(dev);
1616 	}
1617 out:
1618 	rtnl_unlock();
1619 	return 0;
1620 }
1621 
1622 static SIMPLE_DEV_PM_OPS(w840_pm_ops, w840_suspend, w840_resume);
1623 
1624 static struct pci_driver w840_driver = {
1625 	.name		= DRV_NAME,
1626 	.id_table	= w840_pci_tbl,
1627 	.probe		= w840_probe1,
1628 	.remove		= w840_remove1,
1629 	.driver.pm	= &w840_pm_ops,
1630 };
1631 
1632 static int __init w840_init(void)
1633 {
1634 	return pci_register_driver(&w840_driver);
1635 }
1636 
1637 static void __exit w840_exit(void)
1638 {
1639 	pci_unregister_driver(&w840_driver);
1640 }
1641 
1642 module_init(w840_init);
1643 module_exit(w840_exit);
1644