1 /* 8390.c: A general NS8390 ethernet driver core for linux. */
2 /*
3 	Written 1992-94 by Donald Becker.
4 
5 	Copyright 1993 United States Government as represented by the
6 	Director, National Security Agency.
7 
8 	This software may be used and distributed according to the terms
9 	of the GNU General Public License, incorporated herein by reference.
10 
11 	The author may be reached as becker@scyld.com, or C/O
12 	Scyld Computing Corporation
13 	410 Severn Ave., Suite 210
14 	Annapolis MD 21403
15 
16 
17   This is the chip-specific code for many 8390-based ethernet adaptors.
18   This is not a complete driver, it must be combined with board-specific
19   code such as ne.c, wd.c, 3c503.c, etc.
20 
21   Seeing how at least eight drivers use this code, (not counting the
22   PCMCIA ones either) it is easy to break some card by what seems like
23   a simple innocent change. Please contact me or Donald if you think
24   you have found something that needs changing. -- PG
25 
26 
27   Changelog:
28 
29   Paul Gortmaker	: remove set_bit lock, other cleanups.
30   Paul Gortmaker	: add ei_get_8390_hdr() so we can pass skb's to
31 			  ei_block_input() for eth_io_copy_and_sum().
32   Paul Gortmaker	: exchange static int ei_pingpong for a #define,
33 			  also add better Tx error handling.
34   Paul Gortmaker	: rewrite Rx overrun handling as per NS specs.
35   Alexey Kuznetsov	: use the 8390's six bit hash multicast filter.
36   Paul Gortmaker	: tweak ANK's above multicast changes a bit.
37   Paul Gortmaker	: update packet statistics for v2.1.x
38   Alan Cox		: support arbitrary stupid port mappings on the
39 			  68K Macintosh. Support >16bit I/O spaces
40   Paul Gortmaker	: add kmod support for auto-loading of the 8390
41 			  module by all drivers that require it.
42   Alan Cox		: Spinlocking work, added 'BUG_83C690'
43   Paul Gortmaker	: Separate out Tx timeout code from Tx path.
44   Paul Gortmaker	: Remove old unused single Tx buffer code.
45   Hayato Fujiwara	: Add m32r support.
46   Paul Gortmaker	: use skb_padto() instead of stack scratch area
47 
48   Sources:
49   The National Semiconductor LAN Databook, and the 3Com 3c503 databook.
50 
51   */
52 
53 #include <linux/build_bug.h>
54 #include <linux/module.h>
55 #include <linux/kernel.h>
56 #include <linux/jiffies.h>
57 #include <linux/fs.h>
58 #include <linux/types.h>
59 #include <linux/string.h>
60 #include <linux/bitops.h>
61 #include <linux/uaccess.h>
62 #include <linux/io.h>
63 #include <asm/irq.h>
64 #include <linux/delay.h>
65 #include <linux/errno.h>
66 #include <linux/fcntl.h>
67 #include <linux/in.h>
68 #include <linux/interrupt.h>
69 #include <linux/init.h>
70 #include <linux/crc32.h>
71 
72 #include <linux/netdevice.h>
73 #include <linux/etherdevice.h>
74 
75 #define NS8390_CORE
76 #include "8390.h"
77 
78 #define BUG_83C690
79 
80 /* These are the operational function interfaces to board-specific
81    routines.
82 	void reset_8390(struct net_device *dev)
83 		Resets the board associated with DEV, including a hardware reset of
84 		the 8390.  This is only called when there is a transmit timeout, and
85 		it is always followed by 8390_init().
86 	void block_output(struct net_device *dev, int count, const unsigned char *buf,
87 					  int start_page)
88 		Write the COUNT bytes of BUF to the packet buffer at START_PAGE.  The
89 		"page" value uses the 8390's 256-byte pages.
90 	void get_8390_hdr(struct net_device *dev, struct e8390_hdr *hdr, int ring_page)
91 		Read the 4 byte, page aligned 8390 header. *If* there is a
92 		subsequent read, it will be of the rest of the packet.
93 	void block_input(struct net_device *dev, int count, struct sk_buff *skb, int ring_offset)
94 		Read COUNT bytes from the packet buffer into the skb data area. Start
95 		reading from RING_OFFSET, the address as the 8390 sees it.  This will always
96 		follow the read of the 8390 header.
97 */
98 #define ei_reset_8390 (ei_local->reset_8390)
99 #define ei_block_output (ei_local->block_output)
100 #define ei_block_input (ei_local->block_input)
101 #define ei_get_8390_hdr (ei_local->get_8390_hdr)
102 
103 /* Index to functions. */
104 static void ei_tx_intr(struct net_device *dev);
105 static void ei_tx_err(struct net_device *dev);
106 static void ei_receive(struct net_device *dev);
107 static void ei_rx_overrun(struct net_device *dev);
108 
109 /* Routines generic to NS8390-based boards. */
110 static void NS8390_trigger_send(struct net_device *dev, unsigned int length,
111 								int start_page);
112 static void do_set_multicast_list(struct net_device *dev);
113 static void __NS8390_init(struct net_device *dev, int startp);
114 
115 static unsigned version_printed;
116 static int msg_enable;
117 static const int default_msg_level = (NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_RX_ERR |
118 				     NETIF_MSG_TX_ERR);
119 module_param(msg_enable, int, 0444);
120 MODULE_PARM_DESC(msg_enable, "Debug message level (see linux/netdevice.h for bitmap)");
121 
122 /*
123  *	SMP and the 8390 setup.
124  *
125  *	The 8390 isn't exactly designed to be multithreaded on RX/TX. There is
126  *	a page register that controls bank and packet buffer access. We guard
127  *	this with ei_local->page_lock. Nobody should assume or set the page other
128  *	than zero when the lock is not held. Lock holders must restore page 0
129  *	before unlocking. Even pure readers must take the lock to protect in
130  *	page 0.
131  *
132  *	To make life difficult the chip can also be very slow. We therefore can't
133  *	just use spinlocks. For the longer lockups we disable the irq the device
134  *	sits on and hold the lock. We must hold the lock because there is a dual
135  *	processor case other than interrupts (get stats/set multicast list in
136  *	parallel with each other and transmit).
137  *
138  *	Note: in theory we can just disable the irq on the card _but_ there is
139  *	a latency on SMP irq delivery. So we can easily go "disable irq" "sync irqs"
140  *	enter lock, take the queued irq. So we waddle instead of flying.
141  *
142  *	Finally by special arrangement for the purpose of being generally
143  *	annoying the transmit function is called bh atomic. That places
144  *	restrictions on the user context callers as disable_irq won't save
145  *	them.
146  *
147  *	Additional explanation of problems with locking by Alan Cox:
148  *
149  *	"The author (me) didn't use spin_lock_irqsave because the slowness of the
150  *	card means that approach caused horrible problems like losing serial data
151  *	at 38400 baud on some chips. Remember many 8390 nics on PCI were ISA
152  *	chips with FPGA front ends.
153  *
154  *	Ok the logic behind the 8390 is very simple:
155  *
156  *	Things to know
157  *		- IRQ delivery is asynchronous to the PCI bus
158  *		- Blocking the local CPU IRQ via spin locks was too slow
159  *		- The chip has register windows needing locking work
160  *
161  *	So the path was once (I say once as people appear to have changed it
162  *	in the mean time and it now looks rather bogus if the changes to use
163  *	disable_irq_nosync_irqsave are disabling the local IRQ)
164  *
165  *
166  *		Take the page lock
167  *		Mask the IRQ on chip
168  *		Disable the IRQ (but not mask locally- someone seems to have
169  *			broken this with the lock validator stuff)
170  *			[This must be _nosync as the page lock may otherwise
171  *				deadlock us]
172  *		Drop the page lock and turn IRQs back on
173  *
174  *		At this point an existing IRQ may still be running but we can't
175  *		get a new one
176  *
177  *		Take the lock (so we know the IRQ has terminated) but don't mask
178  *	the IRQs on the processor
179  *		Set irqlock [for debug]
180  *
181  *		Transmit (slow as ****)
182  *
183  *		re-enable the IRQ
184  *
185  *
186  *	We have to use disable_irq because otherwise you will get delayed
187  *	interrupts on the APIC bus deadlocking the transmit path.
188  *
189  *	Quite hairy but the chip simply wasn't designed for SMP and you can't
190  *	even ACK an interrupt without risking corrupting other parallel
191  *	activities on the chip." [lkml, 25 Jul 2007]
192  */
193 
194 
195 
196 /**
197  * ei_open - Open/initialize the board.
198  * @dev: network device to initialize
199  *
200  * This routine goes all-out, setting everything
201  * up anew at each open, even though many of these registers should only
202  * need to be set once at boot.
203  */
204 static int __ei_open(struct net_device *dev)
205 {
206 	unsigned long flags;
207 	struct ei_device *ei_local = netdev_priv(dev);
208 
209 	if (dev->watchdog_timeo <= 0)
210 		dev->watchdog_timeo = TX_TIMEOUT;
211 
212 	/*
213 	 *	Grab the page lock so we own the register set, then call
214 	 *	the init function.
215 	 */
216 
217 	spin_lock_irqsave(&ei_local->page_lock, flags);
218 	__NS8390_init(dev, 1);
219 	/* Set the flag before we drop the lock, That way the IRQ arrives
220 	   after its set and we get no silly warnings */
221 	netif_start_queue(dev);
222 	spin_unlock_irqrestore(&ei_local->page_lock, flags);
223 	ei_local->irqlock = 0;
224 	return 0;
225 }
226 
227 /**
228  * ei_close - shut down network device
229  * @dev: network device to close
230  *
231  * Opposite of ei_open(). Only used when "ifconfig <devname> down" is done.
232  */
233 static int __ei_close(struct net_device *dev)
234 {
235 	struct ei_device *ei_local = netdev_priv(dev);
236 	unsigned long flags;
237 
238 	/*
239 	 *	Hold the page lock during close
240 	 */
241 
242 	spin_lock_irqsave(&ei_local->page_lock, flags);
243 	__NS8390_init(dev, 0);
244 	spin_unlock_irqrestore(&ei_local->page_lock, flags);
245 	netif_stop_queue(dev);
246 	return 0;
247 }
248 
249 /**
250  * ei_tx_timeout - handle transmit time out condition
251  * @dev: network device which has apparently fallen asleep
252  *
253  * Called by kernel when device never acknowledges a transmit has
254  * completed (or failed) - i.e. never posted a Tx related interrupt.
255  */
256 
257 static void __ei_tx_timeout(struct net_device *dev, unsigned int txqueue)
258 {
259 	unsigned long e8390_base = dev->base_addr;
260 	struct ei_device *ei_local = netdev_priv(dev);
261 	int txsr, isr, tickssofar = jiffies - dev_trans_start(dev);
262 	unsigned long flags;
263 
264 	dev->stats.tx_errors++;
265 
266 	spin_lock_irqsave(&ei_local->page_lock, flags);
267 	txsr = ei_inb(e8390_base+EN0_TSR);
268 	isr = ei_inb(e8390_base+EN0_ISR);
269 	spin_unlock_irqrestore(&ei_local->page_lock, flags);
270 
271 	netdev_dbg(dev, "Tx timed out, %s TSR=%#2x, ISR=%#2x, t=%d\n",
272 		   (txsr & ENTSR_ABT) ? "excess collisions." :
273 		   (isr) ? "lost interrupt?" : "cable problem?",
274 		   txsr, isr, tickssofar);
275 
276 	if (!isr && !dev->stats.tx_packets) {
277 		/* The 8390 probably hasn't gotten on the cable yet. */
278 		ei_local->interface_num ^= 1;   /* Try a different xcvr.  */
279 	}
280 
281 	/* Ugly but a reset can be slow, yet must be protected */
282 
283 	disable_irq_nosync_lockdep(dev->irq);
284 	spin_lock(&ei_local->page_lock);
285 
286 	/* Try to restart the card.  Perhaps the user has fixed something. */
287 	ei_reset_8390(dev);
288 	__NS8390_init(dev, 1);
289 
290 	spin_unlock(&ei_local->page_lock);
291 	enable_irq_lockdep(dev->irq);
292 	netif_wake_queue(dev);
293 }
294 
295 /**
296  * ei_start_xmit - begin packet transmission
297  * @skb: packet to be sent
298  * @dev: network device to which packet is sent
299  *
300  * Sends a packet to an 8390 network device.
301  */
302 
303 static netdev_tx_t __ei_start_xmit(struct sk_buff *skb,
304 				   struct net_device *dev)
305 {
306 	unsigned long e8390_base = dev->base_addr;
307 	struct ei_device *ei_local = netdev_priv(dev);
308 	int send_length = skb->len, output_page;
309 	unsigned long flags;
310 	char buf[ETH_ZLEN];
311 	char *data = skb->data;
312 
313 	if (skb->len < ETH_ZLEN) {
314 		memset(buf, 0, ETH_ZLEN);	/* more efficient than doing just the needed bits */
315 		memcpy(buf, data, skb->len);
316 		send_length = ETH_ZLEN;
317 		data = buf;
318 	}
319 
320 	/* Mask interrupts from the ethercard.
321 	   SMP: We have to grab the lock here otherwise the IRQ handler
322 	   on another CPU can flip window and race the IRQ mask set. We end
323 	   up trashing the mcast filter not disabling irqs if we don't lock */
324 
325 	spin_lock_irqsave(&ei_local->page_lock, flags);
326 	ei_outb_p(0x00, e8390_base + EN0_IMR);
327 	spin_unlock_irqrestore(&ei_local->page_lock, flags);
328 
329 
330 	/*
331 	 *	Slow phase with lock held.
332 	 */
333 
334 	disable_irq_nosync_lockdep_irqsave(dev->irq, &flags);
335 
336 	spin_lock(&ei_local->page_lock);
337 
338 	ei_local->irqlock = 1;
339 
340 	/*
341 	 * We have two Tx slots available for use. Find the first free
342 	 * slot, and then perform some sanity checks. With two Tx bufs,
343 	 * you get very close to transmitting back-to-back packets. With
344 	 * only one Tx buf, the transmitter sits idle while you reload the
345 	 * card, leaving a substantial gap between each transmitted packet.
346 	 */
347 
348 	if (ei_local->tx1 == 0) {
349 		output_page = ei_local->tx_start_page;
350 		ei_local->tx1 = send_length;
351 		if ((netif_msg_tx_queued(ei_local)) &&
352 		    ei_local->tx2 > 0)
353 			netdev_dbg(dev,
354 				   "idle transmitter tx2=%d, lasttx=%d, txing=%d\n",
355 				   ei_local->tx2, ei_local->lasttx, ei_local->txing);
356 	} else if (ei_local->tx2 == 0) {
357 		output_page = ei_local->tx_start_page + TX_PAGES/2;
358 		ei_local->tx2 = send_length;
359 		if ((netif_msg_tx_queued(ei_local)) &&
360 		    ei_local->tx1 > 0)
361 			netdev_dbg(dev,
362 				   "idle transmitter, tx1=%d, lasttx=%d, txing=%d\n",
363 				   ei_local->tx1, ei_local->lasttx, ei_local->txing);
364 	} else {			/* We should never get here. */
365 		netif_dbg(ei_local, tx_err, dev,
366 			  "No Tx buffers free! tx1=%d tx2=%d last=%d\n",
367 			  ei_local->tx1, ei_local->tx2, ei_local->lasttx);
368 		ei_local->irqlock = 0;
369 		netif_stop_queue(dev);
370 		ei_outb_p(ENISR_ALL, e8390_base + EN0_IMR);
371 		spin_unlock(&ei_local->page_lock);
372 		enable_irq_lockdep_irqrestore(dev->irq, &flags);
373 		dev->stats.tx_errors++;
374 		return NETDEV_TX_BUSY;
375 	}
376 
377 	/*
378 	 * Okay, now upload the packet and trigger a send if the transmitter
379 	 * isn't already sending. If it is busy, the interrupt handler will
380 	 * trigger the send later, upon receiving a Tx done interrupt.
381 	 */
382 
383 	ei_block_output(dev, send_length, data, output_page);
384 
385 	if (!ei_local->txing) {
386 		ei_local->txing = 1;
387 		NS8390_trigger_send(dev, send_length, output_page);
388 		if (output_page == ei_local->tx_start_page) {
389 			ei_local->tx1 = -1;
390 			ei_local->lasttx = -1;
391 		} else {
392 			ei_local->tx2 = -1;
393 			ei_local->lasttx = -2;
394 		}
395 	} else
396 		ei_local->txqueue++;
397 
398 	if (ei_local->tx1 && ei_local->tx2)
399 		netif_stop_queue(dev);
400 	else
401 		netif_start_queue(dev);
402 
403 	/* Turn 8390 interrupts back on. */
404 	ei_local->irqlock = 0;
405 	ei_outb_p(ENISR_ALL, e8390_base + EN0_IMR);
406 
407 	spin_unlock(&ei_local->page_lock);
408 	enable_irq_lockdep_irqrestore(dev->irq, &flags);
409 	skb_tx_timestamp(skb);
410 	dev_consume_skb_any(skb);
411 	dev->stats.tx_bytes += send_length;
412 
413 	return NETDEV_TX_OK;
414 }
415 
416 /**
417  * ei_interrupt - handle the interrupts from an 8390
418  * @irq: interrupt number
419  * @dev_id: a pointer to the net_device
420  *
421  * Handle the ether interface interrupts. We pull packets from
422  * the 8390 via the card specific functions and fire them at the networking
423  * stack. We also handle transmit completions and wake the transmit path if
424  * necessary. We also update the counters and do other housekeeping as
425  * needed.
426  */
427 
428 static irqreturn_t __ei_interrupt(int irq, void *dev_id)
429 {
430 	struct net_device *dev = dev_id;
431 	unsigned long e8390_base = dev->base_addr;
432 	int interrupts, nr_serviced = 0;
433 	struct ei_device *ei_local = netdev_priv(dev);
434 
435 	/*
436 	 *	Protect the irq test too.
437 	 */
438 
439 	spin_lock(&ei_local->page_lock);
440 
441 	if (ei_local->irqlock) {
442 		/*
443 		 * This might just be an interrupt for a PCI device sharing
444 		 * this line
445 		 */
446 		netdev_err(dev, "Interrupted while interrupts are masked! isr=%#2x imr=%#2x\n",
447 			   ei_inb_p(e8390_base + EN0_ISR),
448 			   ei_inb_p(e8390_base + EN0_IMR));
449 		spin_unlock(&ei_local->page_lock);
450 		return IRQ_NONE;
451 	}
452 
453 	/* Change to page 0 and read the intr status reg. */
454 	ei_outb_p(E8390_NODMA+E8390_PAGE0, e8390_base + E8390_CMD);
455 	netif_dbg(ei_local, intr, dev, "interrupt(isr=%#2.2x)\n",
456 		  ei_inb_p(e8390_base + EN0_ISR));
457 
458 	/* !!Assumption!! -- we stay in page 0.	 Don't break this. */
459 	while ((interrupts = ei_inb_p(e8390_base + EN0_ISR)) != 0 &&
460 	       ++nr_serviced < MAX_SERVICE) {
461 		if (!netif_running(dev)) {
462 			netdev_warn(dev, "interrupt from stopped card\n");
463 			/* rmk - acknowledge the interrupts */
464 			ei_outb_p(interrupts, e8390_base + EN0_ISR);
465 			interrupts = 0;
466 			break;
467 		}
468 		if (interrupts & ENISR_OVER)
469 			ei_rx_overrun(dev);
470 		else if (interrupts & (ENISR_RX+ENISR_RX_ERR)) {
471 			/* Got a good (?) packet. */
472 			ei_receive(dev);
473 		}
474 		/* Push the next to-transmit packet through. */
475 		if (interrupts & ENISR_TX)
476 			ei_tx_intr(dev);
477 		else if (interrupts & ENISR_TX_ERR)
478 			ei_tx_err(dev);
479 
480 		if (interrupts & ENISR_COUNTERS) {
481 			dev->stats.rx_frame_errors += ei_inb_p(e8390_base + EN0_COUNTER0);
482 			dev->stats.rx_crc_errors   += ei_inb_p(e8390_base + EN0_COUNTER1);
483 			dev->stats.rx_missed_errors += ei_inb_p(e8390_base + EN0_COUNTER2);
484 			ei_outb_p(ENISR_COUNTERS, e8390_base + EN0_ISR); /* Ack intr. */
485 		}
486 
487 		/* Ignore any RDC interrupts that make it back to here. */
488 		if (interrupts & ENISR_RDC)
489 			ei_outb_p(ENISR_RDC, e8390_base + EN0_ISR);
490 
491 		ei_outb_p(E8390_NODMA+E8390_PAGE0+E8390_START, e8390_base + E8390_CMD);
492 	}
493 
494 	if (interrupts && (netif_msg_intr(ei_local))) {
495 		ei_outb_p(E8390_NODMA+E8390_PAGE0+E8390_START, e8390_base + E8390_CMD);
496 		if (nr_serviced >= MAX_SERVICE) {
497 			/* 0xFF is valid for a card removal */
498 			if (interrupts != 0xFF)
499 				netdev_warn(dev, "Too much work at interrupt, status %#2.2x\n",
500 					    interrupts);
501 			ei_outb_p(ENISR_ALL, e8390_base + EN0_ISR); /* Ack. most intrs. */
502 		} else {
503 			netdev_warn(dev, "unknown interrupt %#2x\n", interrupts);
504 			ei_outb_p(0xff, e8390_base + EN0_ISR); /* Ack. all intrs. */
505 		}
506 	}
507 	spin_unlock(&ei_local->page_lock);
508 	return IRQ_RETVAL(nr_serviced > 0);
509 }
510 
511 #ifdef CONFIG_NET_POLL_CONTROLLER
512 static void __ei_poll(struct net_device *dev)
513 {
514 	disable_irq(dev->irq);
515 	__ei_interrupt(dev->irq, dev);
516 	enable_irq(dev->irq);
517 }
518 #endif
519 
520 /**
521  * ei_tx_err - handle transmitter error
522  * @dev: network device which threw the exception
523  *
524  * A transmitter error has happened. Most likely excess collisions (which
525  * is a fairly normal condition). If the error is one where the Tx will
526  * have been aborted, we try and send another one right away, instead of
527  * letting the failed packet sit and collect dust in the Tx buffer. This
528  * is a much better solution as it avoids kernel based Tx timeouts, and
529  * an unnecessary card reset.
530  *
531  * Called with lock held.
532  */
533 
534 static void ei_tx_err(struct net_device *dev)
535 {
536 	unsigned long e8390_base = dev->base_addr;
537 	/* ei_local is used on some platforms via the EI_SHIFT macro */
538 	struct ei_device *ei_local __maybe_unused = netdev_priv(dev);
539 	unsigned char txsr = ei_inb_p(e8390_base+EN0_TSR);
540 	unsigned char tx_was_aborted = txsr & (ENTSR_ABT+ENTSR_FU);
541 
542 #ifdef VERBOSE_ERROR_DUMP
543 	netdev_dbg(dev, "transmitter error (%#2x):", txsr);
544 	if (txsr & ENTSR_ABT)
545 		pr_cont(" excess-collisions ");
546 	if (txsr & ENTSR_ND)
547 		pr_cont(" non-deferral ");
548 	if (txsr & ENTSR_CRS)
549 		pr_cont(" lost-carrier ");
550 	if (txsr & ENTSR_FU)
551 		pr_cont(" FIFO-underrun ");
552 	if (txsr & ENTSR_CDH)
553 		pr_cont(" lost-heartbeat ");
554 	pr_cont("\n");
555 #endif
556 
557 	ei_outb_p(ENISR_TX_ERR, e8390_base + EN0_ISR); /* Ack intr. */
558 
559 	if (tx_was_aborted)
560 		ei_tx_intr(dev);
561 	else {
562 		dev->stats.tx_errors++;
563 		if (txsr & ENTSR_CRS)
564 			dev->stats.tx_carrier_errors++;
565 		if (txsr & ENTSR_CDH)
566 			dev->stats.tx_heartbeat_errors++;
567 		if (txsr & ENTSR_OWC)
568 			dev->stats.tx_window_errors++;
569 	}
570 }
571 
572 /**
573  * ei_tx_intr - transmit interrupt handler
574  * @dev: network device for which tx intr is handled
575  *
576  * We have finished a transmit: check for errors and then trigger the next
577  * packet to be sent. Called with lock held.
578  */
579 
580 static void ei_tx_intr(struct net_device *dev)
581 {
582 	unsigned long e8390_base = dev->base_addr;
583 	struct ei_device *ei_local = netdev_priv(dev);
584 	int status = ei_inb(e8390_base + EN0_TSR);
585 
586 	ei_outb_p(ENISR_TX, e8390_base + EN0_ISR); /* Ack intr. */
587 
588 	/*
589 	 * There are two Tx buffers, see which one finished, and trigger
590 	 * the send of another one if it exists.
591 	 */
592 	ei_local->txqueue--;
593 
594 	if (ei_local->tx1 < 0) {
595 		if (ei_local->lasttx != 1 && ei_local->lasttx != -1)
596 			pr_err("%s: bogus last_tx_buffer %d, tx1=%d\n",
597 			       ei_local->name, ei_local->lasttx, ei_local->tx1);
598 		ei_local->tx1 = 0;
599 		if (ei_local->tx2 > 0) {
600 			ei_local->txing = 1;
601 			NS8390_trigger_send(dev, ei_local->tx2, ei_local->tx_start_page + 6);
602 			netif_trans_update(dev);
603 			ei_local->tx2 = -1;
604 			ei_local->lasttx = 2;
605 		} else {
606 			ei_local->lasttx = 20;
607 			ei_local->txing = 0;
608 		}
609 	} else if (ei_local->tx2 < 0) {
610 		if (ei_local->lasttx != 2  &&  ei_local->lasttx != -2)
611 			pr_err("%s: bogus last_tx_buffer %d, tx2=%d\n",
612 			       ei_local->name, ei_local->lasttx, ei_local->tx2);
613 		ei_local->tx2 = 0;
614 		if (ei_local->tx1 > 0) {
615 			ei_local->txing = 1;
616 			NS8390_trigger_send(dev, ei_local->tx1, ei_local->tx_start_page);
617 			netif_trans_update(dev);
618 			ei_local->tx1 = -1;
619 			ei_local->lasttx = 1;
620 		} else {
621 			ei_local->lasttx = 10;
622 			ei_local->txing = 0;
623 		}
624 	} /* else
625 		netdev_warn(dev, "unexpected TX-done interrupt, lasttx=%d\n",
626 			    ei_local->lasttx);
627 */
628 
629 	/* Minimize Tx latency: update the statistics after we restart TXing. */
630 	if (status & ENTSR_COL)
631 		dev->stats.collisions++;
632 	if (status & ENTSR_PTX)
633 		dev->stats.tx_packets++;
634 	else {
635 		dev->stats.tx_errors++;
636 		if (status & ENTSR_ABT) {
637 			dev->stats.tx_aborted_errors++;
638 			dev->stats.collisions += 16;
639 		}
640 		if (status & ENTSR_CRS)
641 			dev->stats.tx_carrier_errors++;
642 		if (status & ENTSR_FU)
643 			dev->stats.tx_fifo_errors++;
644 		if (status & ENTSR_CDH)
645 			dev->stats.tx_heartbeat_errors++;
646 		if (status & ENTSR_OWC)
647 			dev->stats.tx_window_errors++;
648 	}
649 	netif_wake_queue(dev);
650 }
651 
652 /**
653  * ei_receive - receive some packets
654  * @dev: network device with which receive will be run
655  *
656  * We have a good packet(s), get it/them out of the buffers.
657  * Called with lock held.
658  */
659 
660 static void ei_receive(struct net_device *dev)
661 {
662 	unsigned long e8390_base = dev->base_addr;
663 	struct ei_device *ei_local = netdev_priv(dev);
664 	unsigned char rxing_page, this_frame, next_frame;
665 	unsigned short current_offset;
666 	int rx_pkt_count = 0;
667 	struct e8390_pkt_hdr rx_frame;
668 	int num_rx_pages = ei_local->stop_page-ei_local->rx_start_page;
669 
670 	while (++rx_pkt_count < 10) {
671 		int pkt_len, pkt_stat;
672 
673 		/* Get the rx page (incoming packet pointer). */
674 		ei_outb_p(E8390_NODMA+E8390_PAGE1, e8390_base + E8390_CMD);
675 		rxing_page = ei_inb_p(e8390_base + EN1_CURPAG);
676 		ei_outb_p(E8390_NODMA+E8390_PAGE0, e8390_base + E8390_CMD);
677 
678 		/* Remove one frame from the ring.  Boundary is always a page behind. */
679 		this_frame = ei_inb_p(e8390_base + EN0_BOUNDARY) + 1;
680 		if (this_frame >= ei_local->stop_page)
681 			this_frame = ei_local->rx_start_page;
682 
683 		/* Someday we'll omit the previous, iff we never get this message.
684 		   (There is at least one clone claimed to have a problem.)
685 
686 		   Keep quiet if it looks like a card removal. One problem here
687 		   is that some clones crash in roughly the same way.
688 		 */
689 		if ((netif_msg_rx_status(ei_local)) &&
690 		    this_frame != ei_local->current_page &&
691 		    (this_frame != 0x0 || rxing_page != 0xFF))
692 			netdev_err(dev,
693 				   "mismatched read page pointers %2x vs %2x\n",
694 				   this_frame, ei_local->current_page);
695 
696 		if (this_frame == rxing_page)	/* Read all the frames? */
697 			break;				/* Done for now */
698 
699 		current_offset = this_frame << 8;
700 		ei_get_8390_hdr(dev, &rx_frame, this_frame);
701 
702 		pkt_len = rx_frame.count - sizeof(struct e8390_pkt_hdr);
703 		pkt_stat = rx_frame.status;
704 
705 		next_frame = this_frame + 1 + ((pkt_len+4)>>8);
706 
707 		/* Check for bogosity warned by 3c503 book: the status byte is never
708 		   written.  This happened a lot during testing! This code should be
709 		   cleaned up someday. */
710 		if (rx_frame.next != next_frame &&
711 		    rx_frame.next != next_frame + 1 &&
712 		    rx_frame.next != next_frame - num_rx_pages &&
713 		    rx_frame.next != next_frame + 1 - num_rx_pages) {
714 			ei_local->current_page = rxing_page;
715 			ei_outb(ei_local->current_page-1, e8390_base+EN0_BOUNDARY);
716 			dev->stats.rx_errors++;
717 			continue;
718 		}
719 
720 		if (pkt_len < 60  ||  pkt_len > 1518) {
721 			netif_dbg(ei_local, rx_status, dev,
722 				  "bogus packet size: %d, status=%#2x nxpg=%#2x\n",
723 				  rx_frame.count, rx_frame.status,
724 				  rx_frame.next);
725 			dev->stats.rx_errors++;
726 			dev->stats.rx_length_errors++;
727 		} else if ((pkt_stat & 0x0F) == ENRSR_RXOK) {
728 			struct sk_buff *skb;
729 
730 			skb = netdev_alloc_skb(dev, pkt_len + 2);
731 			if (skb == NULL) {
732 				netif_err(ei_local, rx_err, dev,
733 					  "Couldn't allocate a sk_buff of size %d\n",
734 					  pkt_len);
735 				dev->stats.rx_dropped++;
736 				break;
737 			} else {
738 				skb_reserve(skb, 2);	/* IP headers on 16 byte boundaries */
739 				skb_put(skb, pkt_len);	/* Make room */
740 				ei_block_input(dev, pkt_len, skb, current_offset + sizeof(rx_frame));
741 				skb->protocol = eth_type_trans(skb, dev);
742 				if (!skb_defer_rx_timestamp(skb))
743 					netif_rx(skb);
744 				dev->stats.rx_packets++;
745 				dev->stats.rx_bytes += pkt_len;
746 				if (pkt_stat & ENRSR_PHY)
747 					dev->stats.multicast++;
748 			}
749 		} else {
750 			netif_err(ei_local, rx_err, dev,
751 				  "bogus packet: status=%#2x nxpg=%#2x size=%d\n",
752 				  rx_frame.status, rx_frame.next,
753 				  rx_frame.count);
754 			dev->stats.rx_errors++;
755 			/* NB: The NIC counts CRC, frame and missed errors. */
756 			if (pkt_stat & ENRSR_FO)
757 				dev->stats.rx_fifo_errors++;
758 		}
759 		next_frame = rx_frame.next;
760 
761 		/* This _should_ never happen: it's here for avoiding bad clones. */
762 		if (next_frame >= ei_local->stop_page) {
763 			netdev_notice(dev, "next frame inconsistency, %#2x\n",
764 				      next_frame);
765 			next_frame = ei_local->rx_start_page;
766 		}
767 		ei_local->current_page = next_frame;
768 		ei_outb_p(next_frame-1, e8390_base+EN0_BOUNDARY);
769 	}
770 
771 	/* We used to also ack ENISR_OVER here, but that would sometimes mask
772 	   a real overrun, leaving the 8390 in a stopped state with rec'vr off. */
773 	ei_outb_p(ENISR_RX+ENISR_RX_ERR, e8390_base+EN0_ISR);
774 }
775 
776 /**
777  * ei_rx_overrun - handle receiver overrun
778  * @dev: network device which threw exception
779  *
780  * We have a receiver overrun: we have to kick the 8390 to get it started
781  * again. Problem is that you have to kick it exactly as NS prescribes in
782  * the updated datasheets, or "the NIC may act in an unpredictable manner."
783  * This includes causing "the NIC to defer indefinitely when it is stopped
784  * on a busy network."  Ugh.
785  * Called with lock held. Don't call this with the interrupts off or your
786  * computer will hate you - it takes 10ms or so.
787  */
788 
789 static void ei_rx_overrun(struct net_device *dev)
790 {
791 	unsigned long e8390_base = dev->base_addr;
792 	unsigned char was_txing, must_resend = 0;
793 	/* ei_local is used on some platforms via the EI_SHIFT macro */
794 	struct ei_device *ei_local __maybe_unused = netdev_priv(dev);
795 
796 	/*
797 	 * Record whether a Tx was in progress and then issue the
798 	 * stop command.
799 	 */
800 	was_txing = ei_inb_p(e8390_base+E8390_CMD) & E8390_TRANS;
801 	ei_outb_p(E8390_NODMA+E8390_PAGE0+E8390_STOP, e8390_base+E8390_CMD);
802 
803 	netif_dbg(ei_local, rx_err, dev, "Receiver overrun\n");
804 	dev->stats.rx_over_errors++;
805 
806 	/*
807 	 * Wait a full Tx time (1.2ms) + some guard time, NS says 1.6ms total.
808 	 * Early datasheets said to poll the reset bit, but now they say that
809 	 * it "is not a reliable indicator and subsequently should be ignored."
810 	 * We wait at least 10ms.
811 	 */
812 
813 	mdelay(10);
814 
815 	/*
816 	 * Reset RBCR[01] back to zero as per magic incantation.
817 	 */
818 	ei_outb_p(0x00, e8390_base+EN0_RCNTLO);
819 	ei_outb_p(0x00, e8390_base+EN0_RCNTHI);
820 
821 	/*
822 	 * See if any Tx was interrupted or not. According to NS, this
823 	 * step is vital, and skipping it will cause no end of havoc.
824 	 */
825 
826 	if (was_txing) {
827 		unsigned char tx_completed = ei_inb_p(e8390_base+EN0_ISR) & (ENISR_TX+ENISR_TX_ERR);
828 		if (!tx_completed)
829 			must_resend = 1;
830 	}
831 
832 	/*
833 	 * Have to enter loopback mode and then restart the NIC before
834 	 * you are allowed to slurp packets up off the ring.
835 	 */
836 	ei_outb_p(E8390_TXOFF, e8390_base + EN0_TXCR);
837 	ei_outb_p(E8390_NODMA + E8390_PAGE0 + E8390_START, e8390_base + E8390_CMD);
838 
839 	/*
840 	 * Clear the Rx ring of all the debris, and ack the interrupt.
841 	 */
842 	ei_receive(dev);
843 	ei_outb_p(ENISR_OVER, e8390_base+EN0_ISR);
844 
845 	/*
846 	 * Leave loopback mode, and resend any packet that got stopped.
847 	 */
848 	ei_outb_p(E8390_TXCONFIG, e8390_base + EN0_TXCR);
849 	if (must_resend)
850 		ei_outb_p(E8390_NODMA + E8390_PAGE0 + E8390_START + E8390_TRANS, e8390_base + E8390_CMD);
851 }
852 
853 /*
854  *	Collect the stats. This is called unlocked and from several contexts.
855  */
856 
857 static struct net_device_stats *__ei_get_stats(struct net_device *dev)
858 {
859 	unsigned long ioaddr = dev->base_addr;
860 	struct ei_device *ei_local = netdev_priv(dev);
861 	unsigned long flags;
862 
863 	/* If the card is stopped, just return the present stats. */
864 	if (!netif_running(dev))
865 		return &dev->stats;
866 
867 	spin_lock_irqsave(&ei_local->page_lock, flags);
868 	/* Read the counter registers, assuming we are in page 0. */
869 	dev->stats.rx_frame_errors  += ei_inb_p(ioaddr + EN0_COUNTER0);
870 	dev->stats.rx_crc_errors    += ei_inb_p(ioaddr + EN0_COUNTER1);
871 	dev->stats.rx_missed_errors += ei_inb_p(ioaddr + EN0_COUNTER2);
872 	spin_unlock_irqrestore(&ei_local->page_lock, flags);
873 
874 	return &dev->stats;
875 }
876 
877 /*
878  * Form the 64 bit 8390 multicast table from the linked list of addresses
879  * associated with this dev structure.
880  */
881 
882 static inline void make_mc_bits(u8 *bits, struct net_device *dev)
883 {
884 	struct netdev_hw_addr *ha;
885 
886 	netdev_for_each_mc_addr(ha, dev) {
887 		u32 crc = ether_crc(ETH_ALEN, ha->addr);
888 		/*
889 		 * The 8390 uses the 6 most significant bits of the
890 		 * CRC to index the multicast table.
891 		 */
892 		bits[crc>>29] |= (1<<((crc>>26)&7));
893 	}
894 }
895 
896 /**
897  * do_set_multicast_list - set/clear multicast filter
898  * @dev: net device for which multicast filter is adjusted
899  *
900  *	Set or clear the multicast filter for this adaptor. May be called
901  *	from a BH in 2.1.x. Must be called with lock held.
902  */
903 
904 static void do_set_multicast_list(struct net_device *dev)
905 {
906 	unsigned long e8390_base = dev->base_addr;
907 	int i;
908 	struct ei_device *ei_local = netdev_priv(dev);
909 
910 	if (!(dev->flags&(IFF_PROMISC|IFF_ALLMULTI))) {
911 		memset(ei_local->mcfilter, 0, 8);
912 		if (!netdev_mc_empty(dev))
913 			make_mc_bits(ei_local->mcfilter, dev);
914 	} else
915 		memset(ei_local->mcfilter, 0xFF, 8);	/* mcast set to accept-all */
916 
917 	/*
918 	 * DP8390 manuals don't specify any magic sequence for altering
919 	 * the multicast regs on an already running card. To be safe, we
920 	 * ensure multicast mode is off prior to loading up the new hash
921 	 * table. If this proves to be not enough, we can always resort
922 	 * to stopping the NIC, loading the table and then restarting.
923 	 *
924 	 * Bug Alert!  The MC regs on the SMC 83C690 (SMC Elite and SMC
925 	 * Elite16) appear to be write-only. The NS 8390 data sheet lists
926 	 * them as r/w so this is a bug.  The SMC 83C790 (SMC Ultra and
927 	 * Ultra32 EISA) appears to have this bug fixed.
928 	 */
929 
930 	if (netif_running(dev))
931 		ei_outb_p(E8390_RXCONFIG, e8390_base + EN0_RXCR);
932 	ei_outb_p(E8390_NODMA + E8390_PAGE1, e8390_base + E8390_CMD);
933 	for (i = 0; i < 8; i++) {
934 		ei_outb_p(ei_local->mcfilter[i], e8390_base + EN1_MULT_SHIFT(i));
935 #ifndef BUG_83C690
936 		if (ei_inb_p(e8390_base + EN1_MULT_SHIFT(i)) != ei_local->mcfilter[i])
937 			netdev_err(dev, "Multicast filter read/write mismap %d\n",
938 				   i);
939 #endif
940 	}
941 	ei_outb_p(E8390_NODMA + E8390_PAGE0, e8390_base + E8390_CMD);
942 
943 	if (dev->flags&IFF_PROMISC)
944 		ei_outb_p(E8390_RXCONFIG | 0x18, e8390_base + EN0_RXCR);
945 	else if (dev->flags & IFF_ALLMULTI || !netdev_mc_empty(dev))
946 		ei_outb_p(E8390_RXCONFIG | 0x08, e8390_base + EN0_RXCR);
947 	else
948 		ei_outb_p(E8390_RXCONFIG, e8390_base + EN0_RXCR);
949 }
950 
951 /*
952  *	Called without lock held. This is invoked from user context and may
953  *	be parallel to just about everything else. Its also fairly quick and
954  *	not called too often. Must protect against both bh and irq users
955  */
956 
957 static void __ei_set_multicast_list(struct net_device *dev)
958 {
959 	unsigned long flags;
960 	struct ei_device *ei_local = netdev_priv(dev);
961 
962 	spin_lock_irqsave(&ei_local->page_lock, flags);
963 	do_set_multicast_list(dev);
964 	spin_unlock_irqrestore(&ei_local->page_lock, flags);
965 }
966 
967 /**
968  * ethdev_setup - init rest of 8390 device struct
969  * @dev: network device structure to init
970  *
971  * Initialize the rest of the 8390 device structure.  Do NOT __init
972  * this, as it is used by 8390 based modular drivers too.
973  */
974 
975 static void ethdev_setup(struct net_device *dev)
976 {
977 	struct ei_device *ei_local = netdev_priv(dev);
978 
979 	ether_setup(dev);
980 
981 	spin_lock_init(&ei_local->page_lock);
982 
983 	ei_local->msg_enable = netif_msg_init(msg_enable, default_msg_level);
984 
985 	if (netif_msg_drv(ei_local) && (version_printed++ == 0))
986 		pr_info("%s", version);
987 }
988 
989 /**
990  * alloc_ei_netdev - alloc_etherdev counterpart for 8390
991  * @size: extra bytes to allocate
992  *
993  * Allocate 8390-specific net_device.
994  */
995 static struct net_device *____alloc_ei_netdev(int size)
996 {
997 	return alloc_netdev(sizeof(struct ei_device) + size, "eth%d",
998 			    NET_NAME_UNKNOWN, ethdev_setup);
999 }
1000 
1001 
1002 
1003 
1004 /* This page of functions should be 8390 generic */
1005 /* Follow National Semi's recommendations for initializing the "NIC". */
1006 
1007 /**
1008  * NS8390_init - initialize 8390 hardware
1009  * @dev: network device to initialize
1010  * @startp: boolean.  non-zero value to initiate chip processing
1011  *
1012  *	Must be called with lock held.
1013  */
1014 
1015 static void __NS8390_init(struct net_device *dev, int startp)
1016 {
1017 	unsigned long e8390_base = dev->base_addr;
1018 	struct ei_device *ei_local = netdev_priv(dev);
1019 	int i;
1020 	int endcfg = ei_local->word16
1021 	    ? (0x48 | ENDCFG_WTS | (ei_local->bigendian ? ENDCFG_BOS : 0))
1022 	    : 0x48;
1023 
1024 	BUILD_BUG_ON(sizeof(struct e8390_pkt_hdr) != 4);
1025 	/* Follow National Semi's recommendations for initing the DP83902. */
1026 	ei_outb_p(E8390_NODMA+E8390_PAGE0+E8390_STOP, e8390_base+E8390_CMD); /* 0x21 */
1027 	ei_outb_p(endcfg, e8390_base + EN0_DCFG);	/* 0x48 or 0x49 */
1028 	/* Clear the remote byte count registers. */
1029 	ei_outb_p(0x00,  e8390_base + EN0_RCNTLO);
1030 	ei_outb_p(0x00,  e8390_base + EN0_RCNTHI);
1031 	/* Set to monitor and loopback mode -- this is vital!. */
1032 	ei_outb_p(E8390_RXOFF, e8390_base + EN0_RXCR); /* 0x20 */
1033 	ei_outb_p(E8390_TXOFF, e8390_base + EN0_TXCR); /* 0x02 */
1034 	/* Set the transmit page and receive ring. */
1035 	ei_outb_p(ei_local->tx_start_page, e8390_base + EN0_TPSR);
1036 	ei_local->tx1 = ei_local->tx2 = 0;
1037 	ei_outb_p(ei_local->rx_start_page, e8390_base + EN0_STARTPG);
1038 	ei_outb_p(ei_local->stop_page-1, e8390_base + EN0_BOUNDARY);	/* 3c503 says 0x3f,NS0x26*/
1039 	ei_local->current_page = ei_local->rx_start_page;		/* assert boundary+1 */
1040 	ei_outb_p(ei_local->stop_page, e8390_base + EN0_STOPPG);
1041 	/* Clear the pending interrupts and mask. */
1042 	ei_outb_p(0xFF, e8390_base + EN0_ISR);
1043 	ei_outb_p(0x00,  e8390_base + EN0_IMR);
1044 
1045 	/* Copy the station address into the DS8390 registers. */
1046 
1047 	ei_outb_p(E8390_NODMA + E8390_PAGE1 + E8390_STOP, e8390_base+E8390_CMD); /* 0x61 */
1048 	for (i = 0; i < 6; i++) {
1049 		ei_outb_p(dev->dev_addr[i], e8390_base + EN1_PHYS_SHIFT(i));
1050 		if ((netif_msg_probe(ei_local)) &&
1051 		    ei_inb_p(e8390_base + EN1_PHYS_SHIFT(i)) != dev->dev_addr[i])
1052 			netdev_err(dev,
1053 				   "Hw. address read/write mismap %d\n", i);
1054 	}
1055 
1056 	ei_outb_p(ei_local->rx_start_page, e8390_base + EN1_CURPAG);
1057 	ei_outb_p(E8390_NODMA+E8390_PAGE0+E8390_STOP, e8390_base+E8390_CMD);
1058 
1059 	ei_local->tx1 = ei_local->tx2 = 0;
1060 	ei_local->txing = 0;
1061 
1062 	if (startp) {
1063 		ei_outb_p(0xff,  e8390_base + EN0_ISR);
1064 		ei_outb_p(ENISR_ALL,  e8390_base + EN0_IMR);
1065 		ei_outb_p(E8390_NODMA+E8390_PAGE0+E8390_START, e8390_base+E8390_CMD);
1066 		ei_outb_p(E8390_TXCONFIG, e8390_base + EN0_TXCR); /* xmit on. */
1067 		/* 3c503 TechMan says rxconfig only after the NIC is started. */
1068 		ei_outb_p(E8390_RXCONFIG, e8390_base + EN0_RXCR); /* rx on,  */
1069 		do_set_multicast_list(dev);	/* (re)load the mcast table */
1070 	}
1071 }
1072 
1073 /* Trigger a transmit start, assuming the length is valid.
1074    Always called with the page lock held */
1075 
1076 static void NS8390_trigger_send(struct net_device *dev, unsigned int length,
1077 								int start_page)
1078 {
1079 	unsigned long e8390_base = dev->base_addr;
1080 	struct ei_device *ei_local __attribute((unused)) = netdev_priv(dev);
1081 
1082 	ei_outb_p(E8390_NODMA+E8390_PAGE0, e8390_base+E8390_CMD);
1083 
1084 	if (ei_inb_p(e8390_base + E8390_CMD) & E8390_TRANS) {
1085 		netdev_warn(dev, "trigger_send() called with the transmitter busy\n");
1086 		return;
1087 	}
1088 	ei_outb_p(length & 0xff, e8390_base + EN0_TCNTLO);
1089 	ei_outb_p(length >> 8, e8390_base + EN0_TCNTHI);
1090 	ei_outb_p(start_page, e8390_base + EN0_TPSR);
1091 	ei_outb_p(E8390_NODMA+E8390_TRANS+E8390_START, e8390_base+E8390_CMD);
1092 }
1093