xref: /linux/drivers/net/ethernet/toshiba/spider_net.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Network device driver for Cell Processor-Based Blade and Celleb platform
4  *
5  * (C) Copyright IBM Corp. 2005
6  * (C) Copyright 2006 TOSHIBA CORPORATION
7  *
8  * Authors : Utz Bacher <utz.bacher@de.ibm.com>
9  *           Jens Osterkamp <Jens.Osterkamp@de.ibm.com>
10  */
11 
12 #include <linux/compiler.h>
13 #include <linux/crc32.h>
14 #include <linux/delay.h>
15 #include <linux/etherdevice.h>
16 #include <linux/ethtool.h>
17 #include <linux/firmware.h>
18 #include <linux/if_vlan.h>
19 #include <linux/in.h>
20 #include <linux/init.h>
21 #include <linux/interrupt.h>
22 #include <linux/gfp.h>
23 #include <linux/ioport.h>
24 #include <linux/ip.h>
25 #include <linux/kernel.h>
26 #include <linux/mii.h>
27 #include <linux/module.h>
28 #include <linux/netdevice.h>
29 #include <linux/device.h>
30 #include <linux/pci.h>
31 #include <linux/skbuff.h>
32 #include <linux/tcp.h>
33 #include <linux/types.h>
34 #include <linux/vmalloc.h>
35 #include <linux/wait.h>
36 #include <linux/workqueue.h>
37 #include <linux/bitops.h>
38 #include <linux/of.h>
39 #include <net/checksum.h>
40 
41 #include "spider_net.h"
42 
43 MODULE_AUTHOR("Utz Bacher <utz.bacher@de.ibm.com> and Jens Osterkamp " \
44 	      "<Jens.Osterkamp@de.ibm.com>");
45 MODULE_DESCRIPTION("Spider Southbridge Gigabit Ethernet driver");
46 MODULE_LICENSE("GPL");
47 MODULE_VERSION(VERSION);
48 MODULE_FIRMWARE(SPIDER_NET_FIRMWARE_NAME);
49 
50 static int rx_descriptors = SPIDER_NET_RX_DESCRIPTORS_DEFAULT;
51 static int tx_descriptors = SPIDER_NET_TX_DESCRIPTORS_DEFAULT;
52 
53 module_param(rx_descriptors, int, 0444);
54 module_param(tx_descriptors, int, 0444);
55 
56 MODULE_PARM_DESC(rx_descriptors, "number of descriptors used " \
57 		 "in rx chains");
58 MODULE_PARM_DESC(tx_descriptors, "number of descriptors used " \
59 		 "in tx chain");
60 
61 char spider_net_driver_name[] = "spidernet";
62 
63 static const struct pci_device_id spider_net_pci_tbl[] = {
64 	{ PCI_VENDOR_ID_TOSHIBA_2, PCI_DEVICE_ID_TOSHIBA_SPIDER_NET,
65 	  PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },
66 	{ 0, }
67 };
68 
69 MODULE_DEVICE_TABLE(pci, spider_net_pci_tbl);
70 
71 /**
72  * spider_net_read_reg - reads an SMMIO register of a card
73  * @card: device structure
74  * @reg: register to read from
75  *
76  * returns the content of the specified SMMIO register.
77  */
78 static inline u32
79 spider_net_read_reg(struct spider_net_card *card, u32 reg)
80 {
81 	/* We use the powerpc specific variants instead of readl_be() because
82 	 * we know spidernet is not a real PCI device and we can thus avoid the
83 	 * performance hit caused by the PCI workarounds.
84 	 */
85 	return in_be32(card->regs + reg);
86 }
87 
88 /**
89  * spider_net_write_reg - writes to an SMMIO register of a card
90  * @card: device structure
91  * @reg: register to write to
92  * @value: value to write into the specified SMMIO register
93  */
94 static inline void
95 spider_net_write_reg(struct spider_net_card *card, u32 reg, u32 value)
96 {
97 	/* We use the powerpc specific variants instead of writel_be() because
98 	 * we know spidernet is not a real PCI device and we can thus avoid the
99 	 * performance hit caused by the PCI workarounds.
100 	 */
101 	out_be32(card->regs + reg, value);
102 }
103 
104 /**
105  * spider_net_write_phy - write to phy register
106  * @netdev: adapter to be written to
107  * @mii_id: id of MII
108  * @reg: PHY register
109  * @val: value to be written to phy register
110  *
111  * spider_net_write_phy_register writes to an arbitrary PHY
112  * register via the spider GPCWOPCMD register. We assume the queue does
113  * not run full (not more than 15 commands outstanding).
114  **/
115 static void
116 spider_net_write_phy(struct net_device *netdev, int mii_id,
117 		     int reg, int val)
118 {
119 	struct spider_net_card *card = netdev_priv(netdev);
120 	u32 writevalue;
121 
122 	writevalue = ((u32)mii_id << 21) |
123 		((u32)reg << 16) | ((u32)val);
124 
125 	spider_net_write_reg(card, SPIDER_NET_GPCWOPCMD, writevalue);
126 }
127 
128 /**
129  * spider_net_read_phy - read from phy register
130  * @netdev: network device to be read from
131  * @mii_id: id of MII
132  * @reg: PHY register
133  *
134  * Returns value read from PHY register
135  *
136  * spider_net_write_phy reads from an arbitrary PHY
137  * register via the spider GPCROPCMD register
138  **/
139 static int
140 spider_net_read_phy(struct net_device *netdev, int mii_id, int reg)
141 {
142 	struct spider_net_card *card = netdev_priv(netdev);
143 	u32 readvalue;
144 
145 	readvalue = ((u32)mii_id << 21) | ((u32)reg << 16);
146 	spider_net_write_reg(card, SPIDER_NET_GPCROPCMD, readvalue);
147 
148 	/* we don't use semaphores to wait for an SPIDER_NET_GPROPCMPINT
149 	 * interrupt, as we poll for the completion of the read operation
150 	 * in spider_net_read_phy. Should take about 50 us
151 	 */
152 	do {
153 		readvalue = spider_net_read_reg(card, SPIDER_NET_GPCROPCMD);
154 	} while (readvalue & SPIDER_NET_GPREXEC);
155 
156 	readvalue &= SPIDER_NET_GPRDAT_MASK;
157 
158 	return readvalue;
159 }
160 
161 /**
162  * spider_net_setup_aneg - initial auto-negotiation setup
163  * @card: device structure
164  **/
165 static void
166 spider_net_setup_aneg(struct spider_net_card *card)
167 {
168 	struct mii_phy *phy = &card->phy;
169 	u32 advertise = 0;
170 	u16 bmsr, estat;
171 
172 	bmsr  = spider_net_read_phy(card->netdev, phy->mii_id, MII_BMSR);
173 	estat = spider_net_read_phy(card->netdev, phy->mii_id, MII_ESTATUS);
174 
175 	if (bmsr & BMSR_10HALF)
176 		advertise |= ADVERTISED_10baseT_Half;
177 	if (bmsr & BMSR_10FULL)
178 		advertise |= ADVERTISED_10baseT_Full;
179 	if (bmsr & BMSR_100HALF)
180 		advertise |= ADVERTISED_100baseT_Half;
181 	if (bmsr & BMSR_100FULL)
182 		advertise |= ADVERTISED_100baseT_Full;
183 
184 	if ((bmsr & BMSR_ESTATEN) && (estat & ESTATUS_1000_TFULL))
185 		advertise |= SUPPORTED_1000baseT_Full;
186 	if ((bmsr & BMSR_ESTATEN) && (estat & ESTATUS_1000_THALF))
187 		advertise |= SUPPORTED_1000baseT_Half;
188 
189 	sungem_phy_probe(phy, phy->mii_id);
190 	phy->def->ops->setup_aneg(phy, advertise);
191 
192 }
193 
194 /**
195  * spider_net_rx_irq_off - switch off rx irq on this spider card
196  * @card: device structure
197  *
198  * switches off rx irq by masking them out in the GHIINTnMSK register
199  */
200 static void
201 spider_net_rx_irq_off(struct spider_net_card *card)
202 {
203 	u32 regvalue;
204 
205 	regvalue = SPIDER_NET_INT0_MASK_VALUE & (~SPIDER_NET_RXINT);
206 	spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK, regvalue);
207 }
208 
209 /**
210  * spider_net_rx_irq_on - switch on rx irq on this spider card
211  * @card: device structure
212  *
213  * switches on rx irq by enabling them in the GHIINTnMSK register
214  */
215 static void
216 spider_net_rx_irq_on(struct spider_net_card *card)
217 {
218 	u32 regvalue;
219 
220 	regvalue = SPIDER_NET_INT0_MASK_VALUE | SPIDER_NET_RXINT;
221 	spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK, regvalue);
222 }
223 
224 /**
225  * spider_net_set_promisc - sets the unicast address or the promiscuous mode
226  * @card: card structure
227  *
228  * spider_net_set_promisc sets the unicast destination address filter and
229  * thus either allows for non-promisc mode or promisc mode
230  */
231 static void
232 spider_net_set_promisc(struct spider_net_card *card)
233 {
234 	u32 macu, macl;
235 	struct net_device *netdev = card->netdev;
236 
237 	if (netdev->flags & IFF_PROMISC) {
238 		/* clear destination entry 0 */
239 		spider_net_write_reg(card, SPIDER_NET_GMRUAFILnR, 0);
240 		spider_net_write_reg(card, SPIDER_NET_GMRUAFILnR + 0x04, 0);
241 		spider_net_write_reg(card, SPIDER_NET_GMRUA0FIL15R,
242 				     SPIDER_NET_PROMISC_VALUE);
243 	} else {
244 		macu = netdev->dev_addr[0];
245 		macu <<= 8;
246 		macu |= netdev->dev_addr[1];
247 		memcpy(&macl, &netdev->dev_addr[2], sizeof(macl));
248 
249 		macu |= SPIDER_NET_UA_DESCR_VALUE;
250 		spider_net_write_reg(card, SPIDER_NET_GMRUAFILnR, macu);
251 		spider_net_write_reg(card, SPIDER_NET_GMRUAFILnR + 0x04, macl);
252 		spider_net_write_reg(card, SPIDER_NET_GMRUA0FIL15R,
253 				     SPIDER_NET_NONPROMISC_VALUE);
254 	}
255 }
256 
257 /**
258  * spider_net_get_descr_status -- returns the status of a descriptor
259  * @hwdescr: descriptor to look at
260  *
261  * returns the status as in the dmac_cmd_status field of the descriptor
262  */
263 static inline int
264 spider_net_get_descr_status(struct spider_net_hw_descr *hwdescr)
265 {
266 	return hwdescr->dmac_cmd_status & SPIDER_NET_DESCR_IND_PROC_MASK;
267 }
268 
269 /**
270  * spider_net_free_chain - free descriptor chain
271  * @card: card structure
272  * @chain: address of chain
273  *
274  */
275 static void
276 spider_net_free_chain(struct spider_net_card *card,
277 		      struct spider_net_descr_chain *chain)
278 {
279 	struct spider_net_descr *descr;
280 
281 	descr = chain->ring;
282 	do {
283 		descr->bus_addr = 0;
284 		descr->hwdescr->next_descr_addr = 0;
285 		descr = descr->next;
286 	} while (descr != chain->ring);
287 
288 	dma_free_coherent(&card->pdev->dev, chain->num_desc * sizeof(struct spider_net_hw_descr),
289 			  chain->hwring, chain->dma_addr);
290 }
291 
292 /**
293  * spider_net_init_chain - alloc and link descriptor chain
294  * @card: card structure
295  * @chain: address of chain
296  *
297  * We manage a circular list that mirrors the hardware structure,
298  * except that the hardware uses bus addresses.
299  *
300  * Returns 0 on success, <0 on failure
301  */
302 static int
303 spider_net_init_chain(struct spider_net_card *card,
304 		       struct spider_net_descr_chain *chain)
305 {
306 	int i;
307 	struct spider_net_descr *descr;
308 	struct spider_net_hw_descr *hwdescr;
309 	dma_addr_t buf;
310 	size_t alloc_size;
311 
312 	alloc_size = chain->num_desc * sizeof(struct spider_net_hw_descr);
313 
314 	chain->hwring = dma_alloc_coherent(&card->pdev->dev, alloc_size,
315 					   &chain->dma_addr, GFP_KERNEL);
316 	if (!chain->hwring)
317 		return -ENOMEM;
318 
319 	/* Set up the hardware pointers in each descriptor */
320 	descr = chain->ring;
321 	hwdescr = chain->hwring;
322 	buf = chain->dma_addr;
323 	for (i=0; i < chain->num_desc; i++, descr++, hwdescr++) {
324 		hwdescr->dmac_cmd_status = SPIDER_NET_DESCR_NOT_IN_USE;
325 		hwdescr->next_descr_addr = 0;
326 
327 		descr->hwdescr = hwdescr;
328 		descr->bus_addr = buf;
329 		descr->next = descr + 1;
330 		descr->prev = descr - 1;
331 
332 		buf += sizeof(struct spider_net_hw_descr);
333 	}
334 	/* do actual circular list */
335 	(descr-1)->next = chain->ring;
336 	chain->ring->prev = descr-1;
337 
338 	spin_lock_init(&chain->lock);
339 	chain->head = chain->ring;
340 	chain->tail = chain->ring;
341 	return 0;
342 }
343 
344 /**
345  * spider_net_free_rx_chain_contents - frees descr contents in rx chain
346  * @card: card structure
347  *
348  * returns 0 on success, <0 on failure
349  */
350 static void
351 spider_net_free_rx_chain_contents(struct spider_net_card *card)
352 {
353 	struct spider_net_descr *descr;
354 
355 	descr = card->rx_chain.head;
356 	do {
357 		if (descr->skb) {
358 			dma_unmap_single(&card->pdev->dev,
359 					 descr->hwdescr->buf_addr,
360 					 SPIDER_NET_MAX_FRAME,
361 					 DMA_BIDIRECTIONAL);
362 			dev_kfree_skb(descr->skb);
363 			descr->skb = NULL;
364 		}
365 		descr = descr->next;
366 	} while (descr != card->rx_chain.head);
367 }
368 
369 /**
370  * spider_net_prepare_rx_descr - Reinitialize RX descriptor
371  * @card: card structure
372  * @descr: descriptor to re-init
373  *
374  * Return 0 on success, <0 on failure.
375  *
376  * Allocates a new rx skb, iommu-maps it and attaches it to the
377  * descriptor. Mark the descriptor as activated, ready-to-use.
378  */
379 static int
380 spider_net_prepare_rx_descr(struct spider_net_card *card,
381 			    struct spider_net_descr *descr)
382 {
383 	struct spider_net_hw_descr *hwdescr = descr->hwdescr;
384 	dma_addr_t buf;
385 	int offset;
386 	int bufsize;
387 
388 	/* we need to round up the buffer size to a multiple of 128 */
389 	bufsize = (SPIDER_NET_MAX_FRAME + SPIDER_NET_RXBUF_ALIGN - 1) &
390 		(~(SPIDER_NET_RXBUF_ALIGN - 1));
391 
392 	/* and we need to have it 128 byte aligned, therefore we allocate a
393 	 * bit more
394 	 */
395 	/* allocate an skb */
396 	descr->skb = netdev_alloc_skb(card->netdev,
397 				      bufsize + SPIDER_NET_RXBUF_ALIGN - 1);
398 	if (!descr->skb) {
399 		if (netif_msg_rx_err(card) && net_ratelimit())
400 			dev_err(&card->netdev->dev,
401 			        "Not enough memory to allocate rx buffer\n");
402 		card->spider_stats.alloc_rx_skb_error++;
403 		return -ENOMEM;
404 	}
405 	hwdescr->buf_size = bufsize;
406 	hwdescr->result_size = 0;
407 	hwdescr->valid_size = 0;
408 	hwdescr->data_status = 0;
409 	hwdescr->data_error = 0;
410 
411 	offset = ((unsigned long)descr->skb->data) &
412 		(SPIDER_NET_RXBUF_ALIGN - 1);
413 	if (offset)
414 		skb_reserve(descr->skb, SPIDER_NET_RXBUF_ALIGN - offset);
415 	/* iommu-map the skb */
416 	buf = dma_map_single(&card->pdev->dev, descr->skb->data,
417 			     SPIDER_NET_MAX_FRAME, DMA_FROM_DEVICE);
418 	if (dma_mapping_error(&card->pdev->dev, buf)) {
419 		dev_kfree_skb_any(descr->skb);
420 		descr->skb = NULL;
421 		if (netif_msg_rx_err(card) && net_ratelimit())
422 			dev_err(&card->netdev->dev, "Could not iommu-map rx buffer\n");
423 		card->spider_stats.rx_iommu_map_error++;
424 		hwdescr->dmac_cmd_status = SPIDER_NET_DESCR_NOT_IN_USE;
425 	} else {
426 		hwdescr->buf_addr = buf;
427 		wmb();
428 		hwdescr->dmac_cmd_status = SPIDER_NET_DESCR_CARDOWNED |
429 					 SPIDER_NET_DMAC_NOINTR_COMPLETE;
430 	}
431 
432 	return 0;
433 }
434 
435 /**
436  * spider_net_enable_rxchtails - sets RX dmac chain tail addresses
437  * @card: card structure
438  *
439  * spider_net_enable_rxchtails sets the RX DMAC chain tail addresses in the
440  * chip by writing to the appropriate register. DMA is enabled in
441  * spider_net_enable_rxdmac.
442  */
443 static inline void
444 spider_net_enable_rxchtails(struct spider_net_card *card)
445 {
446 	/* assume chain is aligned correctly */
447 	spider_net_write_reg(card, SPIDER_NET_GDADCHA ,
448 			     card->rx_chain.tail->bus_addr);
449 }
450 
451 /**
452  * spider_net_enable_rxdmac - enables a receive DMA controller
453  * @card: card structure
454  *
455  * spider_net_enable_rxdmac enables the DMA controller by setting RX_DMA_EN
456  * in the GDADMACCNTR register
457  */
458 static inline void
459 spider_net_enable_rxdmac(struct spider_net_card *card)
460 {
461 	wmb();
462 	spider_net_write_reg(card, SPIDER_NET_GDADMACCNTR,
463 			     SPIDER_NET_DMA_RX_VALUE);
464 }
465 
466 /**
467  * spider_net_disable_rxdmac - disables the receive DMA controller
468  * @card: card structure
469  *
470  * spider_net_disable_rxdmac terminates processing on the DMA controller
471  * by turing off the DMA controller, with the force-end flag set.
472  */
473 static inline void
474 spider_net_disable_rxdmac(struct spider_net_card *card)
475 {
476 	spider_net_write_reg(card, SPIDER_NET_GDADMACCNTR,
477 			     SPIDER_NET_DMA_RX_FEND_VALUE);
478 }
479 
480 /**
481  * spider_net_refill_rx_chain - refills descriptors/skbs in the rx chains
482  * @card: card structure
483  *
484  * refills descriptors in the rx chain: allocates skbs and iommu-maps them.
485  */
486 static void
487 spider_net_refill_rx_chain(struct spider_net_card *card)
488 {
489 	struct spider_net_descr_chain *chain = &card->rx_chain;
490 	unsigned long flags;
491 
492 	/* one context doing the refill (and a second context seeing that
493 	 * and omitting it) is ok. If called by NAPI, we'll be called again
494 	 * as spider_net_decode_one_descr is called several times. If some
495 	 * interrupt calls us, the NAPI is about to clean up anyway.
496 	 */
497 	if (!spin_trylock_irqsave(&chain->lock, flags))
498 		return;
499 
500 	while (spider_net_get_descr_status(chain->head->hwdescr) ==
501 			SPIDER_NET_DESCR_NOT_IN_USE) {
502 		if (spider_net_prepare_rx_descr(card, chain->head))
503 			break;
504 		chain->head = chain->head->next;
505 	}
506 
507 	spin_unlock_irqrestore(&chain->lock, flags);
508 }
509 
510 /**
511  * spider_net_alloc_rx_skbs - Allocates rx skbs in rx descriptor chains
512  * @card: card structure
513  *
514  * Returns 0 on success, <0 on failure.
515  */
516 static int
517 spider_net_alloc_rx_skbs(struct spider_net_card *card)
518 {
519 	struct spider_net_descr_chain *chain = &card->rx_chain;
520 	struct spider_net_descr *start = chain->tail;
521 	struct spider_net_descr *descr = start;
522 
523 	/* Link up the hardware chain pointers */
524 	do {
525 		descr->prev->hwdescr->next_descr_addr = descr->bus_addr;
526 		descr = descr->next;
527 	} while (descr != start);
528 
529 	/* Put at least one buffer into the chain. if this fails,
530 	 * we've got a problem. If not, spider_net_refill_rx_chain
531 	 * will do the rest at the end of this function.
532 	 */
533 	if (spider_net_prepare_rx_descr(card, chain->head))
534 		goto error;
535 	else
536 		chain->head = chain->head->next;
537 
538 	/* This will allocate the rest of the rx buffers;
539 	 * if not, it's business as usual later on.
540 	 */
541 	spider_net_refill_rx_chain(card);
542 	spider_net_enable_rxdmac(card);
543 	return 0;
544 
545 error:
546 	spider_net_free_rx_chain_contents(card);
547 	return -ENOMEM;
548 }
549 
550 /**
551  * spider_net_get_multicast_hash - generates hash for multicast filter table
552  * @netdev: interface device structure
553  * @addr: multicast address
554  *
555  * returns the hash value.
556  *
557  * spider_net_get_multicast_hash calculates a hash value for a given multicast
558  * address, that is used to set the multicast filter tables
559  */
560 static u8
561 spider_net_get_multicast_hash(struct net_device *netdev, __u8 *addr)
562 {
563 	u32 crc;
564 	u8 hash;
565 	char addr_for_crc[ETH_ALEN] = { 0, };
566 	int i, bit;
567 
568 	for (i = 0; i < ETH_ALEN * 8; i++) {
569 		bit = (addr[i / 8] >> (i % 8)) & 1;
570 		addr_for_crc[ETH_ALEN - 1 - i / 8] += bit << (7 - (i % 8));
571 	}
572 
573 	crc = crc32_be(~0, addr_for_crc, netdev->addr_len);
574 
575 	hash = (crc >> 27);
576 	hash <<= 3;
577 	hash |= crc & 7;
578 	hash &= 0xff;
579 
580 	return hash;
581 }
582 
583 /**
584  * spider_net_set_multi - sets multicast addresses and promisc flags
585  * @netdev: interface device structure
586  *
587  * spider_net_set_multi configures multicast addresses as needed for the
588  * netdev interface. It also sets up multicast, allmulti and promisc
589  * flags appropriately
590  */
591 static void
592 spider_net_set_multi(struct net_device *netdev)
593 {
594 	struct netdev_hw_addr *ha;
595 	u8 hash;
596 	int i;
597 	u32 reg;
598 	struct spider_net_card *card = netdev_priv(netdev);
599 	DECLARE_BITMAP(bitmask, SPIDER_NET_MULTICAST_HASHES);
600 
601 	spider_net_set_promisc(card);
602 
603 	if (netdev->flags & IFF_ALLMULTI) {
604 		bitmap_fill(bitmask, SPIDER_NET_MULTICAST_HASHES);
605 		goto write_hash;
606 	}
607 
608 	bitmap_zero(bitmask, SPIDER_NET_MULTICAST_HASHES);
609 
610 	/* well, we know, what the broadcast hash value is: it's xfd
611 	hash = spider_net_get_multicast_hash(netdev, netdev->broadcast); */
612 	__set_bit(0xfd, bitmask);
613 
614 	netdev_for_each_mc_addr(ha, netdev) {
615 		hash = spider_net_get_multicast_hash(netdev, ha->addr);
616 		__set_bit(hash, bitmask);
617 	}
618 
619 write_hash:
620 	for (i = 0; i < SPIDER_NET_MULTICAST_HASHES / 4; i++) {
621 		reg = 0;
622 		if (test_bit(i * 4, bitmask))
623 			reg += 0x08;
624 		reg <<= 8;
625 		if (test_bit(i * 4 + 1, bitmask))
626 			reg += 0x08;
627 		reg <<= 8;
628 		if (test_bit(i * 4 + 2, bitmask))
629 			reg += 0x08;
630 		reg <<= 8;
631 		if (test_bit(i * 4 + 3, bitmask))
632 			reg += 0x08;
633 
634 		spider_net_write_reg(card, SPIDER_NET_GMRMHFILnR + i * 4, reg);
635 	}
636 }
637 
638 /**
639  * spider_net_prepare_tx_descr - fill tx descriptor with skb data
640  * @card: card structure
641  * @skb: packet to use
642  *
643  * returns 0 on success, <0 on failure.
644  *
645  * fills out the descriptor structure with skb data and len. Copies data,
646  * if needed (32bit DMA!)
647  */
648 static int
649 spider_net_prepare_tx_descr(struct spider_net_card *card,
650 			    struct sk_buff *skb)
651 {
652 	struct spider_net_descr_chain *chain = &card->tx_chain;
653 	struct spider_net_descr *descr;
654 	struct spider_net_hw_descr *hwdescr;
655 	dma_addr_t buf;
656 	unsigned long flags;
657 
658 	buf = dma_map_single(&card->pdev->dev, skb->data, skb->len,
659 			     DMA_TO_DEVICE);
660 	if (dma_mapping_error(&card->pdev->dev, buf)) {
661 		if (netif_msg_tx_err(card) && net_ratelimit())
662 			dev_err(&card->netdev->dev, "could not iommu-map packet (%p, %i). "
663 				  "Dropping packet\n", skb->data, skb->len);
664 		card->spider_stats.tx_iommu_map_error++;
665 		return -ENOMEM;
666 	}
667 
668 	spin_lock_irqsave(&chain->lock, flags);
669 	descr = card->tx_chain.head;
670 	if (descr->next == chain->tail->prev) {
671 		spin_unlock_irqrestore(&chain->lock, flags);
672 		dma_unmap_single(&card->pdev->dev, buf, skb->len,
673 				 DMA_TO_DEVICE);
674 		return -ENOMEM;
675 	}
676 	hwdescr = descr->hwdescr;
677 	chain->head = descr->next;
678 
679 	descr->skb = skb;
680 	hwdescr->buf_addr = buf;
681 	hwdescr->buf_size = skb->len;
682 	hwdescr->next_descr_addr = 0;
683 	hwdescr->data_status = 0;
684 
685 	hwdescr->dmac_cmd_status =
686 			SPIDER_NET_DESCR_CARDOWNED | SPIDER_NET_DMAC_TXFRMTL;
687 	spin_unlock_irqrestore(&chain->lock, flags);
688 
689 	if (skb->ip_summed == CHECKSUM_PARTIAL)
690 		switch (ip_hdr(skb)->protocol) {
691 		case IPPROTO_TCP:
692 			hwdescr->dmac_cmd_status |= SPIDER_NET_DMAC_TCP;
693 			break;
694 		case IPPROTO_UDP:
695 			hwdescr->dmac_cmd_status |= SPIDER_NET_DMAC_UDP;
696 			break;
697 		}
698 
699 	/* Chain the bus address, so that the DMA engine finds this descr. */
700 	wmb();
701 	descr->prev->hwdescr->next_descr_addr = descr->bus_addr;
702 
703 	netif_trans_update(card->netdev); /* set netdev watchdog timer */
704 	return 0;
705 }
706 
707 static int
708 spider_net_set_low_watermark(struct spider_net_card *card)
709 {
710 	struct spider_net_descr *descr = card->tx_chain.tail;
711 	struct spider_net_hw_descr *hwdescr;
712 	unsigned long flags;
713 	int status;
714 	int cnt=0;
715 	int i;
716 
717 	/* Measure the length of the queue. Measurement does not
718 	 * need to be precise -- does not need a lock.
719 	 */
720 	while (descr != card->tx_chain.head) {
721 		status = descr->hwdescr->dmac_cmd_status & SPIDER_NET_DESCR_NOT_IN_USE;
722 		if (status == SPIDER_NET_DESCR_NOT_IN_USE)
723 			break;
724 		descr = descr->next;
725 		cnt++;
726 	}
727 
728 	/* If TX queue is short, don't even bother with interrupts */
729 	if (cnt < card->tx_chain.num_desc/4)
730 		return cnt;
731 
732 	/* Set low-watermark 3/4th's of the way into the queue. */
733 	descr = card->tx_chain.tail;
734 	cnt = (cnt*3)/4;
735 	for (i=0;i<cnt; i++)
736 		descr = descr->next;
737 
738 	/* Set the new watermark, clear the old watermark */
739 	spin_lock_irqsave(&card->tx_chain.lock, flags);
740 	descr->hwdescr->dmac_cmd_status |= SPIDER_NET_DESCR_TXDESFLG;
741 	if (card->low_watermark && card->low_watermark != descr) {
742 		hwdescr = card->low_watermark->hwdescr;
743 		hwdescr->dmac_cmd_status =
744 		     hwdescr->dmac_cmd_status & ~SPIDER_NET_DESCR_TXDESFLG;
745 	}
746 	card->low_watermark = descr;
747 	spin_unlock_irqrestore(&card->tx_chain.lock, flags);
748 	return cnt;
749 }
750 
751 /**
752  * spider_net_release_tx_chain - processes sent tx descriptors
753  * @card: adapter structure
754  * @brutal: if set, don't care about whether descriptor seems to be in use
755  *
756  * returns 0 if the tx ring is empty, otherwise 1.
757  *
758  * spider_net_release_tx_chain releases the tx descriptors that spider has
759  * finished with (if non-brutal) or simply release tx descriptors (if brutal).
760  * If some other context is calling this function, we return 1 so that we're
761  * scheduled again (if we were scheduled) and will not lose initiative.
762  */
763 static int
764 spider_net_release_tx_chain(struct spider_net_card *card, int brutal)
765 {
766 	struct net_device *dev = card->netdev;
767 	struct spider_net_descr_chain *chain = &card->tx_chain;
768 	struct spider_net_descr *descr;
769 	struct spider_net_hw_descr *hwdescr;
770 	struct sk_buff *skb;
771 	u32 buf_addr;
772 	unsigned long flags;
773 	int status;
774 
775 	while (1) {
776 		spin_lock_irqsave(&chain->lock, flags);
777 		if (chain->tail == chain->head) {
778 			spin_unlock_irqrestore(&chain->lock, flags);
779 			return 0;
780 		}
781 		descr = chain->tail;
782 		hwdescr = descr->hwdescr;
783 
784 		status = spider_net_get_descr_status(hwdescr);
785 		switch (status) {
786 		case SPIDER_NET_DESCR_COMPLETE:
787 			dev->stats.tx_packets++;
788 			dev->stats.tx_bytes += descr->skb->len;
789 			break;
790 
791 		case SPIDER_NET_DESCR_CARDOWNED:
792 			if (!brutal) {
793 				spin_unlock_irqrestore(&chain->lock, flags);
794 				return 1;
795 			}
796 
797 			/* fallthrough, if we release the descriptors
798 			 * brutally (then we don't care about
799 			 * SPIDER_NET_DESCR_CARDOWNED)
800 			 */
801 			fallthrough;
802 
803 		case SPIDER_NET_DESCR_RESPONSE_ERROR:
804 		case SPIDER_NET_DESCR_PROTECTION_ERROR:
805 		case SPIDER_NET_DESCR_FORCE_END:
806 			if (netif_msg_tx_err(card))
807 				dev_err(&card->netdev->dev, "forcing end of tx descriptor "
808 				       "with status x%02x\n", status);
809 			dev->stats.tx_errors++;
810 			break;
811 
812 		default:
813 			dev->stats.tx_dropped++;
814 			if (!brutal) {
815 				spin_unlock_irqrestore(&chain->lock, flags);
816 				return 1;
817 			}
818 		}
819 
820 		chain->tail = descr->next;
821 		hwdescr->dmac_cmd_status |= SPIDER_NET_DESCR_NOT_IN_USE;
822 		skb = descr->skb;
823 		descr->skb = NULL;
824 		buf_addr = hwdescr->buf_addr;
825 		spin_unlock_irqrestore(&chain->lock, flags);
826 
827 		/* unmap the skb */
828 		if (skb) {
829 			dma_unmap_single(&card->pdev->dev, buf_addr, skb->len,
830 					 DMA_TO_DEVICE);
831 			dev_consume_skb_any(skb);
832 		}
833 	}
834 	return 0;
835 }
836 
837 /**
838  * spider_net_kick_tx_dma - enables TX DMA processing
839  * @card: card structure
840  *
841  * This routine will start the transmit DMA running if
842  * it is not already running. This routine ned only be
843  * called when queueing a new packet to an empty tx queue.
844  * Writes the current tx chain head as start address
845  * of the tx descriptor chain and enables the transmission
846  * DMA engine.
847  */
848 static inline void
849 spider_net_kick_tx_dma(struct spider_net_card *card)
850 {
851 	struct spider_net_descr *descr;
852 
853 	if (spider_net_read_reg(card, SPIDER_NET_GDTDMACCNTR) &
854 			SPIDER_NET_TX_DMA_EN)
855 		goto out;
856 
857 	descr = card->tx_chain.tail;
858 	for (;;) {
859 		if (spider_net_get_descr_status(descr->hwdescr) ==
860 				SPIDER_NET_DESCR_CARDOWNED) {
861 			spider_net_write_reg(card, SPIDER_NET_GDTDCHA,
862 					descr->bus_addr);
863 			spider_net_write_reg(card, SPIDER_NET_GDTDMACCNTR,
864 					SPIDER_NET_DMA_TX_VALUE);
865 			break;
866 		}
867 		if (descr == card->tx_chain.head)
868 			break;
869 		descr = descr->next;
870 	}
871 
872 out:
873 	mod_timer(&card->tx_timer, jiffies + SPIDER_NET_TX_TIMER);
874 }
875 
876 /**
877  * spider_net_xmit - transmits a frame over the device
878  * @skb: packet to send out
879  * @netdev: interface device structure
880  *
881  * returns NETDEV_TX_OK on success, NETDEV_TX_BUSY on failure
882  */
883 static netdev_tx_t
884 spider_net_xmit(struct sk_buff *skb, struct net_device *netdev)
885 {
886 	int cnt;
887 	struct spider_net_card *card = netdev_priv(netdev);
888 
889 	spider_net_release_tx_chain(card, 0);
890 
891 	if (spider_net_prepare_tx_descr(card, skb) != 0) {
892 		netdev->stats.tx_dropped++;
893 		netif_stop_queue(netdev);
894 		return NETDEV_TX_BUSY;
895 	}
896 
897 	cnt = spider_net_set_low_watermark(card);
898 	if (cnt < 5)
899 		spider_net_kick_tx_dma(card);
900 	return NETDEV_TX_OK;
901 }
902 
903 /**
904  * spider_net_cleanup_tx_ring - cleans up the TX ring
905  * @t: timer context used to obtain the pointer to net card data structure
906  *
907  * spider_net_cleanup_tx_ring is called by either the tx_timer
908  * or from the NAPI polling routine.
909  * This routine releases resources associted with transmitted
910  * packets, including updating the queue tail pointer.
911  */
912 static void
913 spider_net_cleanup_tx_ring(struct timer_list *t)
914 {
915 	struct spider_net_card *card = from_timer(card, t, tx_timer);
916 	if ((spider_net_release_tx_chain(card, 0) != 0) &&
917 	    (card->netdev->flags & IFF_UP)) {
918 		spider_net_kick_tx_dma(card);
919 		netif_wake_queue(card->netdev);
920 	}
921 }
922 
923 /**
924  * spider_net_do_ioctl - called for device ioctls
925  * @netdev: interface device structure
926  * @ifr: request parameter structure for ioctl
927  * @cmd: command code for ioctl
928  *
929  * returns 0 on success, <0 on failure. Currently, we have no special ioctls.
930  * -EOPNOTSUPP is returned, if an unknown ioctl was requested
931  */
932 static int
933 spider_net_do_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
934 {
935 	switch (cmd) {
936 	default:
937 		return -EOPNOTSUPP;
938 	}
939 }
940 
941 /**
942  * spider_net_pass_skb_up - takes an skb from a descriptor and passes it on
943  * @descr: descriptor to process
944  * @card: card structure
945  *
946  * Fills out skb structure and passes the data to the stack.
947  * The descriptor state is not changed.
948  */
949 static void
950 spider_net_pass_skb_up(struct spider_net_descr *descr,
951 		       struct spider_net_card *card)
952 {
953 	struct spider_net_hw_descr *hwdescr = descr->hwdescr;
954 	struct sk_buff *skb = descr->skb;
955 	struct net_device *netdev = card->netdev;
956 	u32 data_status = hwdescr->data_status;
957 	u32 data_error = hwdescr->data_error;
958 
959 	skb_put(skb, hwdescr->valid_size);
960 
961 	/* the card seems to add 2 bytes of junk in front
962 	 * of the ethernet frame
963 	 */
964 #define SPIDER_MISALIGN		2
965 	skb_pull(skb, SPIDER_MISALIGN);
966 	skb->protocol = eth_type_trans(skb, netdev);
967 
968 	/* checksum offload */
969 	skb_checksum_none_assert(skb);
970 	if (netdev->features & NETIF_F_RXCSUM) {
971 		if ( ( (data_status & SPIDER_NET_DATA_STATUS_CKSUM_MASK) ==
972 		       SPIDER_NET_DATA_STATUS_CKSUM_MASK) &&
973 		     !(data_error & SPIDER_NET_DATA_ERR_CKSUM_MASK))
974 			skb->ip_summed = CHECKSUM_UNNECESSARY;
975 	}
976 
977 	if (data_status & SPIDER_NET_VLAN_PACKET) {
978 		/* further enhancements: HW-accel VLAN */
979 	}
980 
981 	/* update netdevice statistics */
982 	netdev->stats.rx_packets++;
983 	netdev->stats.rx_bytes += skb->len;
984 
985 	/* pass skb up to stack */
986 	netif_receive_skb(skb);
987 }
988 
989 static void show_rx_chain(struct spider_net_card *card)
990 {
991 	struct spider_net_descr_chain *chain = &card->rx_chain;
992 	struct spider_net_descr *start= chain->tail;
993 	struct spider_net_descr *descr= start;
994 	struct spider_net_hw_descr *hwd = start->hwdescr;
995 	struct device *dev = &card->netdev->dev;
996 	u32 curr_desc, next_desc;
997 	int status;
998 
999 	int tot = 0;
1000 	int cnt = 0;
1001 	int off = start - chain->ring;
1002 	int cstat = hwd->dmac_cmd_status;
1003 
1004 	dev_info(dev, "Total number of descrs=%d\n",
1005 		chain->num_desc);
1006 	dev_info(dev, "Chain tail located at descr=%d, status=0x%x\n",
1007 		off, cstat);
1008 
1009 	curr_desc = spider_net_read_reg(card, SPIDER_NET_GDACTDPA);
1010 	next_desc = spider_net_read_reg(card, SPIDER_NET_GDACNEXTDA);
1011 
1012 	status = cstat;
1013 	do
1014 	{
1015 		hwd = descr->hwdescr;
1016 		off = descr - chain->ring;
1017 		status = hwd->dmac_cmd_status;
1018 
1019 		if (descr == chain->head)
1020 			dev_info(dev, "Chain head is at %d, head status=0x%x\n",
1021 			         off, status);
1022 
1023 		if (curr_desc == descr->bus_addr)
1024 			dev_info(dev, "HW curr desc (GDACTDPA) is at %d, status=0x%x\n",
1025 			         off, status);
1026 
1027 		if (next_desc == descr->bus_addr)
1028 			dev_info(dev, "HW next desc (GDACNEXTDA) is at %d, status=0x%x\n",
1029 			         off, status);
1030 
1031 		if (hwd->next_descr_addr == 0)
1032 			dev_info(dev, "chain is cut at %d\n", off);
1033 
1034 		if (cstat != status) {
1035 			int from = (chain->num_desc + off - cnt) % chain->num_desc;
1036 			int to = (chain->num_desc + off - 1) % chain->num_desc;
1037 			dev_info(dev, "Have %d (from %d to %d) descrs "
1038 			         "with stat=0x%08x\n", cnt, from, to, cstat);
1039 			cstat = status;
1040 			cnt = 0;
1041 		}
1042 
1043 		cnt ++;
1044 		tot ++;
1045 		descr = descr->next;
1046 	} while (descr != start);
1047 
1048 	dev_info(dev, "Last %d descrs with stat=0x%08x "
1049 	         "for a total of %d descrs\n", cnt, cstat, tot);
1050 
1051 #ifdef DEBUG
1052 	/* Now dump the whole ring */
1053 	descr = start;
1054 	do
1055 	{
1056 		struct spider_net_hw_descr *hwd = descr->hwdescr;
1057 		status = spider_net_get_descr_status(hwd);
1058 		cnt = descr - chain->ring;
1059 		dev_info(dev, "Descr %d stat=0x%08x skb=%p\n",
1060 		         cnt, status, descr->skb);
1061 		dev_info(dev, "bus addr=%08x buf addr=%08x sz=%d\n",
1062 		         descr->bus_addr, hwd->buf_addr, hwd->buf_size);
1063 		dev_info(dev, "next=%08x result sz=%d valid sz=%d\n",
1064 		         hwd->next_descr_addr, hwd->result_size,
1065 		         hwd->valid_size);
1066 		dev_info(dev, "dmac=%08x data stat=%08x data err=%08x\n",
1067 		         hwd->dmac_cmd_status, hwd->data_status,
1068 		         hwd->data_error);
1069 		dev_info(dev, "\n");
1070 
1071 		descr = descr->next;
1072 	} while (descr != start);
1073 #endif
1074 
1075 }
1076 
1077 /**
1078  * spider_net_resync_head_ptr - Advance head ptr past empty descrs
1079  * @card: card structure
1080  *
1081  * If the driver fails to keep up and empty the queue, then the
1082  * hardware wil run out of room to put incoming packets. This
1083  * will cause the hardware to skip descrs that are full (instead
1084  * of halting/retrying). Thus, once the driver runs, it wil need
1085  * to "catch up" to where the hardware chain pointer is at.
1086  */
1087 static void spider_net_resync_head_ptr(struct spider_net_card *card)
1088 {
1089 	unsigned long flags;
1090 	struct spider_net_descr_chain *chain = &card->rx_chain;
1091 	struct spider_net_descr *descr;
1092 	int i, status;
1093 
1094 	/* Advance head pointer past any empty descrs */
1095 	descr = chain->head;
1096 	status = spider_net_get_descr_status(descr->hwdescr);
1097 
1098 	if (status == SPIDER_NET_DESCR_NOT_IN_USE)
1099 		return;
1100 
1101 	spin_lock_irqsave(&chain->lock, flags);
1102 
1103 	descr = chain->head;
1104 	status = spider_net_get_descr_status(descr->hwdescr);
1105 	for (i=0; i<chain->num_desc; i++) {
1106 		if (status != SPIDER_NET_DESCR_CARDOWNED) break;
1107 		descr = descr->next;
1108 		status = spider_net_get_descr_status(descr->hwdescr);
1109 	}
1110 	chain->head = descr;
1111 
1112 	spin_unlock_irqrestore(&chain->lock, flags);
1113 }
1114 
1115 static int spider_net_resync_tail_ptr(struct spider_net_card *card)
1116 {
1117 	struct spider_net_descr_chain *chain = &card->rx_chain;
1118 	struct spider_net_descr *descr;
1119 	int i, status;
1120 
1121 	/* Advance tail pointer past any empty and reaped descrs */
1122 	descr = chain->tail;
1123 	status = spider_net_get_descr_status(descr->hwdescr);
1124 
1125 	for (i=0; i<chain->num_desc; i++) {
1126 		if ((status != SPIDER_NET_DESCR_CARDOWNED) &&
1127 		    (status != SPIDER_NET_DESCR_NOT_IN_USE)) break;
1128 		descr = descr->next;
1129 		status = spider_net_get_descr_status(descr->hwdescr);
1130 	}
1131 	chain->tail = descr;
1132 
1133 	if ((i == chain->num_desc) || (i == 0))
1134 		return 1;
1135 	return 0;
1136 }
1137 
1138 /**
1139  * spider_net_decode_one_descr - processes an RX descriptor
1140  * @card: card structure
1141  *
1142  * Returns 1 if a packet has been sent to the stack, otherwise 0.
1143  *
1144  * Processes an RX descriptor by iommu-unmapping the data buffer
1145  * and passing the packet up to the stack. This function is called
1146  * in softirq context, e.g. either bottom half from interrupt or
1147  * NAPI polling context.
1148  */
1149 static int
1150 spider_net_decode_one_descr(struct spider_net_card *card)
1151 {
1152 	struct net_device *dev = card->netdev;
1153 	struct spider_net_descr_chain *chain = &card->rx_chain;
1154 	struct spider_net_descr *descr = chain->tail;
1155 	struct spider_net_hw_descr *hwdescr = descr->hwdescr;
1156 	u32 hw_buf_addr;
1157 	int status;
1158 
1159 	status = spider_net_get_descr_status(hwdescr);
1160 
1161 	/* Nothing in the descriptor, or ring must be empty */
1162 	if ((status == SPIDER_NET_DESCR_CARDOWNED) ||
1163 	    (status == SPIDER_NET_DESCR_NOT_IN_USE))
1164 		return 0;
1165 
1166 	/* descriptor definitively used -- move on tail */
1167 	chain->tail = descr->next;
1168 
1169 	/* unmap descriptor */
1170 	hw_buf_addr = hwdescr->buf_addr;
1171 	hwdescr->buf_addr = 0xffffffff;
1172 	dma_unmap_single(&card->pdev->dev, hw_buf_addr, SPIDER_NET_MAX_FRAME,
1173 			 DMA_FROM_DEVICE);
1174 
1175 	if ( (status == SPIDER_NET_DESCR_RESPONSE_ERROR) ||
1176 	     (status == SPIDER_NET_DESCR_PROTECTION_ERROR) ||
1177 	     (status == SPIDER_NET_DESCR_FORCE_END) ) {
1178 		if (netif_msg_rx_err(card))
1179 			dev_err(&dev->dev,
1180 			       "dropping RX descriptor with state %d\n", status);
1181 		dev->stats.rx_dropped++;
1182 		goto bad_desc;
1183 	}
1184 
1185 	if ( (status != SPIDER_NET_DESCR_COMPLETE) &&
1186 	     (status != SPIDER_NET_DESCR_FRAME_END) ) {
1187 		if (netif_msg_rx_err(card))
1188 			dev_err(&card->netdev->dev,
1189 			       "RX descriptor with unknown state %d\n", status);
1190 		card->spider_stats.rx_desc_unk_state++;
1191 		goto bad_desc;
1192 	}
1193 
1194 	/* The cases we'll throw away the packet immediately */
1195 	if (hwdescr->data_error & SPIDER_NET_DESTROY_RX_FLAGS) {
1196 		if (netif_msg_rx_err(card))
1197 			dev_err(&card->netdev->dev,
1198 			       "error in received descriptor found, "
1199 			       "data_status=x%08x, data_error=x%08x\n",
1200 			       hwdescr->data_status, hwdescr->data_error);
1201 		goto bad_desc;
1202 	}
1203 
1204 	if (hwdescr->dmac_cmd_status & SPIDER_NET_DESCR_BAD_STATUS) {
1205 		dev_err(&card->netdev->dev, "bad status, cmd_status=x%08x\n",
1206 			       hwdescr->dmac_cmd_status);
1207 		pr_err("buf_addr=x%08x\n", hw_buf_addr);
1208 		pr_err("buf_size=x%08x\n", hwdescr->buf_size);
1209 		pr_err("next_descr_addr=x%08x\n", hwdescr->next_descr_addr);
1210 		pr_err("result_size=x%08x\n", hwdescr->result_size);
1211 		pr_err("valid_size=x%08x\n", hwdescr->valid_size);
1212 		pr_err("data_status=x%08x\n", hwdescr->data_status);
1213 		pr_err("data_error=x%08x\n", hwdescr->data_error);
1214 		pr_err("which=%ld\n", descr - card->rx_chain.ring);
1215 
1216 		card->spider_stats.rx_desc_error++;
1217 		goto bad_desc;
1218 	}
1219 
1220 	/* Ok, we've got a packet in descr */
1221 	spider_net_pass_skb_up(descr, card);
1222 	descr->skb = NULL;
1223 	hwdescr->dmac_cmd_status = SPIDER_NET_DESCR_NOT_IN_USE;
1224 	return 1;
1225 
1226 bad_desc:
1227 	if (netif_msg_rx_err(card))
1228 		show_rx_chain(card);
1229 	dev_kfree_skb_irq(descr->skb);
1230 	descr->skb = NULL;
1231 	hwdescr->dmac_cmd_status = SPIDER_NET_DESCR_NOT_IN_USE;
1232 	return 0;
1233 }
1234 
1235 /**
1236  * spider_net_poll - NAPI poll function called by the stack to return packets
1237  * @napi: napi device structure
1238  * @budget: number of packets we can pass to the stack at most
1239  *
1240  * returns 0 if no more packets available to the driver/stack. Returns 1,
1241  * if the quota is exceeded, but the driver has still packets.
1242  *
1243  * spider_net_poll returns all packets from the rx descriptors to the stack
1244  * (using netif_receive_skb). If all/enough packets are up, the driver
1245  * reenables interrupts and returns 0. If not, 1 is returned.
1246  */
1247 static int spider_net_poll(struct napi_struct *napi, int budget)
1248 {
1249 	struct spider_net_card *card = container_of(napi, struct spider_net_card, napi);
1250 	int packets_done = 0;
1251 
1252 	while (packets_done < budget) {
1253 		if (!spider_net_decode_one_descr(card))
1254 			break;
1255 
1256 		packets_done++;
1257 	}
1258 
1259 	if ((packets_done == 0) && (card->num_rx_ints != 0)) {
1260 		if (!spider_net_resync_tail_ptr(card))
1261 			packets_done = budget;
1262 		spider_net_resync_head_ptr(card);
1263 	}
1264 	card->num_rx_ints = 0;
1265 
1266 	spider_net_refill_rx_chain(card);
1267 	spider_net_enable_rxdmac(card);
1268 
1269 	spider_net_cleanup_tx_ring(&card->tx_timer);
1270 
1271 	/* if all packets are in the stack, enable interrupts and return 0 */
1272 	/* if not, return 1 */
1273 	if (packets_done < budget) {
1274 		napi_complete_done(napi, packets_done);
1275 		spider_net_rx_irq_on(card);
1276 		card->ignore_rx_ramfull = 0;
1277 	}
1278 
1279 	return packets_done;
1280 }
1281 
1282 /**
1283  * spider_net_set_mac - sets the MAC of an interface
1284  * @netdev: interface device structure
1285  * @p: pointer to new MAC address
1286  *
1287  * Returns 0 on success, <0 on failure. Currently, we don't support this
1288  * and will always return EOPNOTSUPP.
1289  */
1290 static int
1291 spider_net_set_mac(struct net_device *netdev, void *p)
1292 {
1293 	struct spider_net_card *card = netdev_priv(netdev);
1294 	u32 macl, macu, regvalue;
1295 	struct sockaddr *addr = p;
1296 
1297 	if (!is_valid_ether_addr(addr->sa_data))
1298 		return -EADDRNOTAVAIL;
1299 
1300 	eth_hw_addr_set(netdev, addr->sa_data);
1301 
1302 	/* switch off GMACTPE and GMACRPE */
1303 	regvalue = spider_net_read_reg(card, SPIDER_NET_GMACOPEMD);
1304 	regvalue &= ~((1 << 5) | (1 << 6));
1305 	spider_net_write_reg(card, SPIDER_NET_GMACOPEMD, regvalue);
1306 
1307 	/* write mac */
1308 	macu = (netdev->dev_addr[0]<<24) + (netdev->dev_addr[1]<<16) +
1309 		(netdev->dev_addr[2]<<8) + (netdev->dev_addr[3]);
1310 	macl = (netdev->dev_addr[4]<<8) + (netdev->dev_addr[5]);
1311 	spider_net_write_reg(card, SPIDER_NET_GMACUNIMACU, macu);
1312 	spider_net_write_reg(card, SPIDER_NET_GMACUNIMACL, macl);
1313 
1314 	/* switch GMACTPE and GMACRPE back on */
1315 	regvalue = spider_net_read_reg(card, SPIDER_NET_GMACOPEMD);
1316 	regvalue |= ((1 << 5) | (1 << 6));
1317 	spider_net_write_reg(card, SPIDER_NET_GMACOPEMD, regvalue);
1318 
1319 	spider_net_set_promisc(card);
1320 
1321 	return 0;
1322 }
1323 
1324 /**
1325  * spider_net_link_reset
1326  * @netdev: net device structure
1327  *
1328  * This is called when the PHY_LINK signal is asserted. For the blade this is
1329  * not connected so we should never get here.
1330  *
1331  */
1332 static void
1333 spider_net_link_reset(struct net_device *netdev)
1334 {
1335 
1336 	struct spider_net_card *card = netdev_priv(netdev);
1337 
1338 	del_timer_sync(&card->aneg_timer);
1339 
1340 	/* clear interrupt, block further interrupts */
1341 	spider_net_write_reg(card, SPIDER_NET_GMACST,
1342 			     spider_net_read_reg(card, SPIDER_NET_GMACST));
1343 	spider_net_write_reg(card, SPIDER_NET_GMACINTEN, 0);
1344 
1345 	/* reset phy and setup aneg */
1346 	card->aneg_count = 0;
1347 	card->medium = BCM54XX_COPPER;
1348 	spider_net_setup_aneg(card);
1349 	mod_timer(&card->aneg_timer, jiffies + SPIDER_NET_ANEG_TIMER);
1350 
1351 }
1352 
1353 /**
1354  * spider_net_handle_error_irq - handles errors raised by an interrupt
1355  * @card: card structure
1356  * @status_reg: interrupt status register 0 (GHIINT0STS)
1357  * @error_reg1: interrupt status register 1 (GHIINT1STS)
1358  * @error_reg2: interrupt status register 2 (GHIINT2STS)
1359  *
1360  * spider_net_handle_error_irq treats or ignores all error conditions
1361  * found when an interrupt is presented
1362  */
1363 static void
1364 spider_net_handle_error_irq(struct spider_net_card *card, u32 status_reg,
1365 			    u32 error_reg1, u32 error_reg2)
1366 {
1367 	u32 i;
1368 	int show_error = 1;
1369 
1370 	/* check GHIINT0STS ************************************/
1371 	if (status_reg)
1372 		for (i = 0; i < 32; i++)
1373 			if (status_reg & (1<<i))
1374 				switch (i)
1375 	{
1376 	/* let error_reg1 and error_reg2 evaluation decide, what to do
1377 	case SPIDER_NET_PHYINT:
1378 	case SPIDER_NET_GMAC2INT:
1379 	case SPIDER_NET_GMAC1INT:
1380 	case SPIDER_NET_GFIFOINT:
1381 	case SPIDER_NET_DMACINT:
1382 	case SPIDER_NET_GSYSINT:
1383 		break; */
1384 
1385 	case SPIDER_NET_GIPSINT:
1386 		show_error = 0;
1387 		break;
1388 
1389 	case SPIDER_NET_GPWOPCMPINT:
1390 		/* PHY write operation completed */
1391 		show_error = 0;
1392 		break;
1393 	case SPIDER_NET_GPROPCMPINT:
1394 		/* PHY read operation completed */
1395 		/* we don't use semaphores, as we poll for the completion
1396 		 * of the read operation in spider_net_read_phy. Should take
1397 		 * about 50 us
1398 		 */
1399 		show_error = 0;
1400 		break;
1401 	case SPIDER_NET_GPWFFINT:
1402 		/* PHY command queue full */
1403 		if (netif_msg_intr(card))
1404 			dev_err(&card->netdev->dev, "PHY write queue full\n");
1405 		show_error = 0;
1406 		break;
1407 
1408 	/* case SPIDER_NET_GRMDADRINT: not used. print a message */
1409 	/* case SPIDER_NET_GRMARPINT: not used. print a message */
1410 	/* case SPIDER_NET_GRMMPINT: not used. print a message */
1411 
1412 	case SPIDER_NET_GDTDEN0INT:
1413 		/* someone has set TX_DMA_EN to 0 */
1414 		show_error = 0;
1415 		break;
1416 
1417 	case SPIDER_NET_GDDDEN0INT:
1418 	case SPIDER_NET_GDCDEN0INT:
1419 	case SPIDER_NET_GDBDEN0INT:
1420 	case SPIDER_NET_GDADEN0INT:
1421 		/* someone has set RX_DMA_EN to 0 */
1422 		show_error = 0;
1423 		break;
1424 
1425 	/* RX interrupts */
1426 	case SPIDER_NET_GDDFDCINT:
1427 	case SPIDER_NET_GDCFDCINT:
1428 	case SPIDER_NET_GDBFDCINT:
1429 	case SPIDER_NET_GDAFDCINT:
1430 	/* case SPIDER_NET_GDNMINT: not used. print a message */
1431 	/* case SPIDER_NET_GCNMINT: not used. print a message */
1432 	/* case SPIDER_NET_GBNMINT: not used. print a message */
1433 	/* case SPIDER_NET_GANMINT: not used. print a message */
1434 	/* case SPIDER_NET_GRFNMINT: not used. print a message */
1435 		show_error = 0;
1436 		break;
1437 
1438 	/* TX interrupts */
1439 	case SPIDER_NET_GDTFDCINT:
1440 		show_error = 0;
1441 		break;
1442 	case SPIDER_NET_GTTEDINT:
1443 		show_error = 0;
1444 		break;
1445 	case SPIDER_NET_GDTDCEINT:
1446 		/* chain end. If a descriptor should be sent, kick off
1447 		 * tx dma
1448 		if (card->tx_chain.tail != card->tx_chain.head)
1449 			spider_net_kick_tx_dma(card);
1450 		*/
1451 		show_error = 0;
1452 		break;
1453 
1454 	/* case SPIDER_NET_G1TMCNTINT: not used. print a message */
1455 	/* case SPIDER_NET_GFREECNTINT: not used. print a message */
1456 	}
1457 
1458 	/* check GHIINT1STS ************************************/
1459 	if (error_reg1)
1460 		for (i = 0; i < 32; i++)
1461 			if (error_reg1 & (1<<i))
1462 				switch (i)
1463 	{
1464 	case SPIDER_NET_GTMFLLINT:
1465 		/* TX RAM full may happen on a usual case.
1466 		 * Logging is not needed.
1467 		 */
1468 		show_error = 0;
1469 		break;
1470 	case SPIDER_NET_GRFDFLLINT:
1471 	case SPIDER_NET_GRFCFLLINT:
1472 	case SPIDER_NET_GRFBFLLINT:
1473 	case SPIDER_NET_GRFAFLLINT:
1474 	case SPIDER_NET_GRMFLLINT:
1475 		/* Could happen when rx chain is full */
1476 		if (card->ignore_rx_ramfull == 0) {
1477 			card->ignore_rx_ramfull = 1;
1478 			spider_net_resync_head_ptr(card);
1479 			spider_net_refill_rx_chain(card);
1480 			spider_net_enable_rxdmac(card);
1481 			card->num_rx_ints ++;
1482 			napi_schedule(&card->napi);
1483 		}
1484 		show_error = 0;
1485 		break;
1486 
1487 	/* case SPIDER_NET_GTMSHTINT: problem, print a message */
1488 	case SPIDER_NET_GDTINVDINT:
1489 		/* allrighty. tx from previous descr ok */
1490 		show_error = 0;
1491 		break;
1492 
1493 	/* chain end */
1494 	case SPIDER_NET_GDDDCEINT:
1495 	case SPIDER_NET_GDCDCEINT:
1496 	case SPIDER_NET_GDBDCEINT:
1497 	case SPIDER_NET_GDADCEINT:
1498 		spider_net_resync_head_ptr(card);
1499 		spider_net_refill_rx_chain(card);
1500 		spider_net_enable_rxdmac(card);
1501 		card->num_rx_ints ++;
1502 		napi_schedule(&card->napi);
1503 		show_error = 0;
1504 		break;
1505 
1506 	/* invalid descriptor */
1507 	case SPIDER_NET_GDDINVDINT:
1508 	case SPIDER_NET_GDCINVDINT:
1509 	case SPIDER_NET_GDBINVDINT:
1510 	case SPIDER_NET_GDAINVDINT:
1511 		/* Could happen when rx chain is full */
1512 		spider_net_resync_head_ptr(card);
1513 		spider_net_refill_rx_chain(card);
1514 		spider_net_enable_rxdmac(card);
1515 		card->num_rx_ints ++;
1516 		napi_schedule(&card->napi);
1517 		show_error = 0;
1518 		break;
1519 
1520 	/* case SPIDER_NET_GDTRSERINT: problem, print a message */
1521 	/* case SPIDER_NET_GDDRSERINT: problem, print a message */
1522 	/* case SPIDER_NET_GDCRSERINT: problem, print a message */
1523 	/* case SPIDER_NET_GDBRSERINT: problem, print a message */
1524 	/* case SPIDER_NET_GDARSERINT: problem, print a message */
1525 	/* case SPIDER_NET_GDSERINT: problem, print a message */
1526 	/* case SPIDER_NET_GDTPTERINT: problem, print a message */
1527 	/* case SPIDER_NET_GDDPTERINT: problem, print a message */
1528 	/* case SPIDER_NET_GDCPTERINT: problem, print a message */
1529 	/* case SPIDER_NET_GDBPTERINT: problem, print a message */
1530 	/* case SPIDER_NET_GDAPTERINT: problem, print a message */
1531 	default:
1532 		show_error = 1;
1533 		break;
1534 	}
1535 
1536 	/* check GHIINT2STS ************************************/
1537 	if (error_reg2)
1538 		for (i = 0; i < 32; i++)
1539 			if (error_reg2 & (1<<i))
1540 				switch (i)
1541 	{
1542 	/* there is nothing we can (want  to) do at this time. Log a
1543 	 * message, we can switch on and off the specific values later on
1544 	case SPIDER_NET_GPROPERINT:
1545 	case SPIDER_NET_GMCTCRSNGINT:
1546 	case SPIDER_NET_GMCTLCOLINT:
1547 	case SPIDER_NET_GMCTTMOTINT:
1548 	case SPIDER_NET_GMCRCAERINT:
1549 	case SPIDER_NET_GMCRCALERINT:
1550 	case SPIDER_NET_GMCRALNERINT:
1551 	case SPIDER_NET_GMCROVRINT:
1552 	case SPIDER_NET_GMCRRNTINT:
1553 	case SPIDER_NET_GMCRRXERINT:
1554 	case SPIDER_NET_GTITCSERINT:
1555 	case SPIDER_NET_GTIFMTERINT:
1556 	case SPIDER_NET_GTIPKTRVKINT:
1557 	case SPIDER_NET_GTISPINGINT:
1558 	case SPIDER_NET_GTISADNGINT:
1559 	case SPIDER_NET_GTISPDNGINT:
1560 	case SPIDER_NET_GRIFMTERINT:
1561 	case SPIDER_NET_GRIPKTRVKINT:
1562 	case SPIDER_NET_GRISPINGINT:
1563 	case SPIDER_NET_GRISADNGINT:
1564 	case SPIDER_NET_GRISPDNGINT:
1565 		break;
1566 	*/
1567 		default:
1568 			break;
1569 	}
1570 
1571 	if ((show_error) && (netif_msg_intr(card)) && net_ratelimit())
1572 		dev_err(&card->netdev->dev, "Error interrupt, GHIINT0STS = 0x%08x, "
1573 		       "GHIINT1STS = 0x%08x, GHIINT2STS = 0x%08x\n",
1574 		       status_reg, error_reg1, error_reg2);
1575 
1576 	/* clear interrupt sources */
1577 	spider_net_write_reg(card, SPIDER_NET_GHIINT1STS, error_reg1);
1578 	spider_net_write_reg(card, SPIDER_NET_GHIINT2STS, error_reg2);
1579 }
1580 
1581 /**
1582  * spider_net_interrupt - interrupt handler for spider_net
1583  * @irq: interrupt number
1584  * @ptr: pointer to net_device
1585  *
1586  * returns IRQ_HANDLED, if interrupt was for driver, or IRQ_NONE, if no
1587  * interrupt found raised by card.
1588  *
1589  * This is the interrupt handler, that turns off
1590  * interrupts for this device and makes the stack poll the driver
1591  */
1592 static irqreturn_t
1593 spider_net_interrupt(int irq, void *ptr)
1594 {
1595 	struct net_device *netdev = ptr;
1596 	struct spider_net_card *card = netdev_priv(netdev);
1597 	u32 status_reg, error_reg1, error_reg2;
1598 
1599 	status_reg = spider_net_read_reg(card, SPIDER_NET_GHIINT0STS);
1600 	error_reg1 = spider_net_read_reg(card, SPIDER_NET_GHIINT1STS);
1601 	error_reg2 = spider_net_read_reg(card, SPIDER_NET_GHIINT2STS);
1602 
1603 	if (!(status_reg & SPIDER_NET_INT0_MASK_VALUE) &&
1604 	    !(error_reg1 & SPIDER_NET_INT1_MASK_VALUE) &&
1605 	    !(error_reg2 & SPIDER_NET_INT2_MASK_VALUE))
1606 		return IRQ_NONE;
1607 
1608 	if (status_reg & SPIDER_NET_RXINT ) {
1609 		spider_net_rx_irq_off(card);
1610 		napi_schedule(&card->napi);
1611 		card->num_rx_ints ++;
1612 	}
1613 	if (status_reg & SPIDER_NET_TXINT)
1614 		napi_schedule(&card->napi);
1615 
1616 	if (status_reg & SPIDER_NET_LINKINT)
1617 		spider_net_link_reset(netdev);
1618 
1619 	if (status_reg & SPIDER_NET_ERRINT )
1620 		spider_net_handle_error_irq(card, status_reg,
1621 					    error_reg1, error_reg2);
1622 
1623 	/* clear interrupt sources */
1624 	spider_net_write_reg(card, SPIDER_NET_GHIINT0STS, status_reg);
1625 
1626 	return IRQ_HANDLED;
1627 }
1628 
1629 #ifdef CONFIG_NET_POLL_CONTROLLER
1630 /**
1631  * spider_net_poll_controller - artificial interrupt for netconsole etc.
1632  * @netdev: interface device structure
1633  *
1634  * see Documentation/networking/netconsole.rst
1635  */
1636 static void
1637 spider_net_poll_controller(struct net_device *netdev)
1638 {
1639 	disable_irq(netdev->irq);
1640 	spider_net_interrupt(netdev->irq, netdev);
1641 	enable_irq(netdev->irq);
1642 }
1643 #endif /* CONFIG_NET_POLL_CONTROLLER */
1644 
1645 /**
1646  * spider_net_enable_interrupts - enable interrupts
1647  * @card: card structure
1648  *
1649  * spider_net_enable_interrupt enables several interrupts
1650  */
1651 static void
1652 spider_net_enable_interrupts(struct spider_net_card *card)
1653 {
1654 	spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK,
1655 			     SPIDER_NET_INT0_MASK_VALUE);
1656 	spider_net_write_reg(card, SPIDER_NET_GHIINT1MSK,
1657 			     SPIDER_NET_INT1_MASK_VALUE);
1658 	spider_net_write_reg(card, SPIDER_NET_GHIINT2MSK,
1659 			     SPIDER_NET_INT2_MASK_VALUE);
1660 }
1661 
1662 /**
1663  * spider_net_disable_interrupts - disable interrupts
1664  * @card: card structure
1665  *
1666  * spider_net_disable_interrupts disables all the interrupts
1667  */
1668 static void
1669 spider_net_disable_interrupts(struct spider_net_card *card)
1670 {
1671 	spider_net_write_reg(card, SPIDER_NET_GHIINT0MSK, 0);
1672 	spider_net_write_reg(card, SPIDER_NET_GHIINT1MSK, 0);
1673 	spider_net_write_reg(card, SPIDER_NET_GHIINT2MSK, 0);
1674 	spider_net_write_reg(card, SPIDER_NET_GMACINTEN, 0);
1675 }
1676 
1677 /**
1678  * spider_net_init_card - initializes the card
1679  * @card: card structure
1680  *
1681  * spider_net_init_card initializes the card so that other registers can
1682  * be used
1683  */
1684 static void
1685 spider_net_init_card(struct spider_net_card *card)
1686 {
1687 	spider_net_write_reg(card, SPIDER_NET_CKRCTRL,
1688 			     SPIDER_NET_CKRCTRL_STOP_VALUE);
1689 
1690 	spider_net_write_reg(card, SPIDER_NET_CKRCTRL,
1691 			     SPIDER_NET_CKRCTRL_RUN_VALUE);
1692 
1693 	/* trigger ETOMOD signal */
1694 	spider_net_write_reg(card, SPIDER_NET_GMACOPEMD,
1695 		spider_net_read_reg(card, SPIDER_NET_GMACOPEMD) | 0x4);
1696 
1697 	spider_net_disable_interrupts(card);
1698 }
1699 
1700 /**
1701  * spider_net_enable_card - enables the card by setting all kinds of regs
1702  * @card: card structure
1703  *
1704  * spider_net_enable_card sets a lot of SMMIO registers to enable the device
1705  */
1706 static void
1707 spider_net_enable_card(struct spider_net_card *card)
1708 {
1709 	int i;
1710 	/* the following array consists of (register),(value) pairs
1711 	 * that are set in this function. A register of 0 ends the list
1712 	 */
1713 	u32 regs[][2] = {
1714 		{ SPIDER_NET_GRESUMINTNUM, 0 },
1715 		{ SPIDER_NET_GREINTNUM, 0 },
1716 
1717 		/* set interrupt frame number registers */
1718 		/* clear the single DMA engine registers first */
1719 		{ SPIDER_NET_GFAFRMNUM, SPIDER_NET_GFXFRAMES_VALUE },
1720 		{ SPIDER_NET_GFBFRMNUM, SPIDER_NET_GFXFRAMES_VALUE },
1721 		{ SPIDER_NET_GFCFRMNUM, SPIDER_NET_GFXFRAMES_VALUE },
1722 		{ SPIDER_NET_GFDFRMNUM, SPIDER_NET_GFXFRAMES_VALUE },
1723 		/* then set, what we really need */
1724 		{ SPIDER_NET_GFFRMNUM, SPIDER_NET_FRAMENUM_VALUE },
1725 
1726 		/* timer counter registers and stuff */
1727 		{ SPIDER_NET_GFREECNNUM, 0 },
1728 		{ SPIDER_NET_GONETIMENUM, 0 },
1729 		{ SPIDER_NET_GTOUTFRMNUM, 0 },
1730 
1731 		/* RX mode setting */
1732 		{ SPIDER_NET_GRXMDSET, SPIDER_NET_RXMODE_VALUE },
1733 		/* TX mode setting */
1734 		{ SPIDER_NET_GTXMDSET, SPIDER_NET_TXMODE_VALUE },
1735 		/* IPSEC mode setting */
1736 		{ SPIDER_NET_GIPSECINIT, SPIDER_NET_IPSECINIT_VALUE },
1737 
1738 		{ SPIDER_NET_GFTRESTRT, SPIDER_NET_RESTART_VALUE },
1739 
1740 		{ SPIDER_NET_GMRWOLCTRL, 0 },
1741 		{ SPIDER_NET_GTESTMD, 0x10000000 },
1742 		{ SPIDER_NET_GTTQMSK, 0x00400040 },
1743 
1744 		{ SPIDER_NET_GMACINTEN, 0 },
1745 
1746 		/* flow control stuff */
1747 		{ SPIDER_NET_GMACAPAUSE, SPIDER_NET_MACAPAUSE_VALUE },
1748 		{ SPIDER_NET_GMACTXPAUSE, SPIDER_NET_TXPAUSE_VALUE },
1749 
1750 		{ SPIDER_NET_GMACBSTLMT, SPIDER_NET_BURSTLMT_VALUE },
1751 		{ 0, 0}
1752 	};
1753 
1754 	i = 0;
1755 	while (regs[i][0]) {
1756 		spider_net_write_reg(card, regs[i][0], regs[i][1]);
1757 		i++;
1758 	}
1759 
1760 	/* clear unicast filter table entries 1 to 14 */
1761 	for (i = 1; i <= 14; i++) {
1762 		spider_net_write_reg(card,
1763 				     SPIDER_NET_GMRUAFILnR + i * 8,
1764 				     0x00080000);
1765 		spider_net_write_reg(card,
1766 				     SPIDER_NET_GMRUAFILnR + i * 8 + 4,
1767 				     0x00000000);
1768 	}
1769 
1770 	spider_net_write_reg(card, SPIDER_NET_GMRUA0FIL15R, 0x08080000);
1771 
1772 	spider_net_write_reg(card, SPIDER_NET_ECMODE, SPIDER_NET_ECMODE_VALUE);
1773 
1774 	/* set chain tail address for RX chains and
1775 	 * enable DMA
1776 	 */
1777 	spider_net_enable_rxchtails(card);
1778 	spider_net_enable_rxdmac(card);
1779 
1780 	spider_net_write_reg(card, SPIDER_NET_GRXDMAEN, SPIDER_NET_WOL_VALUE);
1781 
1782 	spider_net_write_reg(card, SPIDER_NET_GMACLENLMT,
1783 			     SPIDER_NET_LENLMT_VALUE);
1784 	spider_net_write_reg(card, SPIDER_NET_GMACOPEMD,
1785 			     SPIDER_NET_OPMODE_VALUE);
1786 
1787 	spider_net_write_reg(card, SPIDER_NET_GDTDMACCNTR,
1788 			     SPIDER_NET_GDTBSTA);
1789 }
1790 
1791 /**
1792  * spider_net_download_firmware - loads firmware into the adapter
1793  * @card: card structure
1794  * @firmware_ptr: pointer to firmware data
1795  *
1796  * spider_net_download_firmware loads the firmware data into the
1797  * adapter. It assumes the length etc. to be allright.
1798  */
1799 static int
1800 spider_net_download_firmware(struct spider_net_card *card,
1801 			     const void *firmware_ptr)
1802 {
1803 	int sequencer, i;
1804 	const u32 *fw_ptr = firmware_ptr;
1805 
1806 	/* stop sequencers */
1807 	spider_net_write_reg(card, SPIDER_NET_GSINIT,
1808 			     SPIDER_NET_STOP_SEQ_VALUE);
1809 
1810 	for (sequencer = 0; sequencer < SPIDER_NET_FIRMWARE_SEQS;
1811 	     sequencer++) {
1812 		spider_net_write_reg(card,
1813 				     SPIDER_NET_GSnPRGADR + sequencer * 8, 0);
1814 		for (i = 0; i < SPIDER_NET_FIRMWARE_SEQWORDS; i++) {
1815 			spider_net_write_reg(card, SPIDER_NET_GSnPRGDAT +
1816 					     sequencer * 8, *fw_ptr);
1817 			fw_ptr++;
1818 		}
1819 	}
1820 
1821 	if (spider_net_read_reg(card, SPIDER_NET_GSINIT))
1822 		return -EIO;
1823 
1824 	spider_net_write_reg(card, SPIDER_NET_GSINIT,
1825 			     SPIDER_NET_RUN_SEQ_VALUE);
1826 
1827 	return 0;
1828 }
1829 
1830 /**
1831  * spider_net_init_firmware - reads in firmware parts
1832  * @card: card structure
1833  *
1834  * Returns 0 on success, <0 on failure
1835  *
1836  * spider_net_init_firmware opens the sequencer firmware and does some basic
1837  * checks. This function opens and releases the firmware structure. A call
1838  * to download the firmware is performed before the release.
1839  *
1840  * Firmware format
1841  * ===============
1842  * spider_fw.bin is expected to be a file containing 6*1024*4 bytes, 4k being
1843  * the program for each sequencer. Use the command
1844  *    tail -q -n +2 Seq_code1_0x088.txt Seq_code2_0x090.txt              \
1845  *         Seq_code3_0x098.txt Seq_code4_0x0A0.txt Seq_code5_0x0A8.txt   \
1846  *         Seq_code6_0x0B0.txt | xxd -r -p -c4 > spider_fw.bin
1847  *
1848  * to generate spider_fw.bin, if you have sequencer programs with something
1849  * like the following contents for each sequencer:
1850  *    <ONE LINE COMMENT>
1851  *    <FIRST 4-BYTES-WORD FOR SEQUENCER>
1852  *    <SECOND 4-BYTES-WORD FOR SEQUENCER>
1853  *     ...
1854  *    <1024th 4-BYTES-WORD FOR SEQUENCER>
1855  */
1856 static int
1857 spider_net_init_firmware(struct spider_net_card *card)
1858 {
1859 	struct firmware *firmware = NULL;
1860 	struct device_node *dn;
1861 	const u8 *fw_prop = NULL;
1862 	int err = -ENOENT;
1863 	int fw_size;
1864 
1865 	if (request_firmware((const struct firmware **)&firmware,
1866 			     SPIDER_NET_FIRMWARE_NAME, &card->pdev->dev) == 0) {
1867 		if ( (firmware->size != SPIDER_NET_FIRMWARE_LEN) &&
1868 		     netif_msg_probe(card) ) {
1869 			dev_err(&card->netdev->dev,
1870 			       "Incorrect size of spidernet firmware in " \
1871 			       "filesystem. Looking in host firmware...\n");
1872 			goto try_host_fw;
1873 		}
1874 		err = spider_net_download_firmware(card, firmware->data);
1875 
1876 		release_firmware(firmware);
1877 		if (err)
1878 			goto try_host_fw;
1879 
1880 		goto done;
1881 	}
1882 
1883 try_host_fw:
1884 	dn = pci_device_to_OF_node(card->pdev);
1885 	if (!dn)
1886 		goto out_err;
1887 
1888 	fw_prop = of_get_property(dn, "firmware", &fw_size);
1889 	if (!fw_prop)
1890 		goto out_err;
1891 
1892 	if ( (fw_size != SPIDER_NET_FIRMWARE_LEN) &&
1893 	     netif_msg_probe(card) ) {
1894 		dev_err(&card->netdev->dev,
1895 		       "Incorrect size of spidernet firmware in host firmware\n");
1896 		goto done;
1897 	}
1898 
1899 	err = spider_net_download_firmware(card, fw_prop);
1900 
1901 done:
1902 	return err;
1903 out_err:
1904 	if (netif_msg_probe(card))
1905 		dev_err(&card->netdev->dev,
1906 		       "Couldn't find spidernet firmware in filesystem " \
1907 		       "or host firmware\n");
1908 	return err;
1909 }
1910 
1911 /**
1912  * spider_net_open - called upon ifonfig up
1913  * @netdev: interface device structure
1914  *
1915  * returns 0 on success, <0 on failure
1916  *
1917  * spider_net_open allocates all the descriptors and memory needed for
1918  * operation, sets up multicast list and enables interrupts
1919  */
1920 int
1921 spider_net_open(struct net_device *netdev)
1922 {
1923 	struct spider_net_card *card = netdev_priv(netdev);
1924 	int result;
1925 
1926 	result = spider_net_init_firmware(card);
1927 	if (result)
1928 		goto init_firmware_failed;
1929 
1930 	/* start probing with copper */
1931 	card->aneg_count = 0;
1932 	card->medium = BCM54XX_COPPER;
1933 	spider_net_setup_aneg(card);
1934 	if (card->phy.def->phy_id)
1935 		mod_timer(&card->aneg_timer, jiffies + SPIDER_NET_ANEG_TIMER);
1936 
1937 	result = spider_net_init_chain(card, &card->tx_chain);
1938 	if (result)
1939 		goto alloc_tx_failed;
1940 	card->low_watermark = NULL;
1941 
1942 	result = spider_net_init_chain(card, &card->rx_chain);
1943 	if (result)
1944 		goto alloc_rx_failed;
1945 
1946 	/* Allocate rx skbs */
1947 	result = spider_net_alloc_rx_skbs(card);
1948 	if (result)
1949 		goto alloc_skbs_failed;
1950 
1951 	spider_net_set_multi(netdev);
1952 
1953 	/* further enhancement: setup hw vlan, if needed */
1954 
1955 	result = -EBUSY;
1956 	if (request_irq(netdev->irq, spider_net_interrupt,
1957 			     IRQF_SHARED, netdev->name, netdev))
1958 		goto register_int_failed;
1959 
1960 	spider_net_enable_card(card);
1961 
1962 	netif_start_queue(netdev);
1963 	netif_carrier_on(netdev);
1964 	napi_enable(&card->napi);
1965 
1966 	spider_net_enable_interrupts(card);
1967 
1968 	return 0;
1969 
1970 register_int_failed:
1971 	spider_net_free_rx_chain_contents(card);
1972 alloc_skbs_failed:
1973 	spider_net_free_chain(card, &card->rx_chain);
1974 alloc_rx_failed:
1975 	spider_net_free_chain(card, &card->tx_chain);
1976 alloc_tx_failed:
1977 	del_timer_sync(&card->aneg_timer);
1978 init_firmware_failed:
1979 	return result;
1980 }
1981 
1982 /**
1983  * spider_net_link_phy
1984  * @t: timer context used to obtain the pointer to net card data structure
1985  */
1986 static void spider_net_link_phy(struct timer_list *t)
1987 {
1988 	struct spider_net_card *card = from_timer(card, t, aneg_timer);
1989 	struct mii_phy *phy = &card->phy;
1990 
1991 	/* if link didn't come up after SPIDER_NET_ANEG_TIMEOUT tries, setup phy again */
1992 	if (card->aneg_count > SPIDER_NET_ANEG_TIMEOUT) {
1993 
1994 		pr_debug("%s: link is down trying to bring it up\n",
1995 			 card->netdev->name);
1996 
1997 		switch (card->medium) {
1998 		case BCM54XX_COPPER:
1999 			/* enable fiber with autonegotiation first */
2000 			if (phy->def->ops->enable_fiber)
2001 				phy->def->ops->enable_fiber(phy, 1);
2002 			card->medium = BCM54XX_FIBER;
2003 			break;
2004 
2005 		case BCM54XX_FIBER:
2006 			/* fiber didn't come up, try to disable fiber autoneg */
2007 			if (phy->def->ops->enable_fiber)
2008 				phy->def->ops->enable_fiber(phy, 0);
2009 			card->medium = BCM54XX_UNKNOWN;
2010 			break;
2011 
2012 		case BCM54XX_UNKNOWN:
2013 			/* copper, fiber with and without failed,
2014 			 * retry from beginning
2015 			 */
2016 			spider_net_setup_aneg(card);
2017 			card->medium = BCM54XX_COPPER;
2018 			break;
2019 		}
2020 
2021 		card->aneg_count = 0;
2022 		mod_timer(&card->aneg_timer, jiffies + SPIDER_NET_ANEG_TIMER);
2023 		return;
2024 	}
2025 
2026 	/* link still not up, try again later */
2027 	if (!(phy->def->ops->poll_link(phy))) {
2028 		card->aneg_count++;
2029 		mod_timer(&card->aneg_timer, jiffies + SPIDER_NET_ANEG_TIMER);
2030 		return;
2031 	}
2032 
2033 	/* link came up, get abilities */
2034 	phy->def->ops->read_link(phy);
2035 
2036 	spider_net_write_reg(card, SPIDER_NET_GMACST,
2037 			     spider_net_read_reg(card, SPIDER_NET_GMACST));
2038 	spider_net_write_reg(card, SPIDER_NET_GMACINTEN, 0x4);
2039 
2040 	if (phy->speed == 1000)
2041 		spider_net_write_reg(card, SPIDER_NET_GMACMODE, 0x00000001);
2042 	else
2043 		spider_net_write_reg(card, SPIDER_NET_GMACMODE, 0);
2044 
2045 	card->aneg_count = 0;
2046 
2047 	pr_info("%s: link up, %i Mbps, %s-duplex %sautoneg.\n",
2048 		card->netdev->name, phy->speed,
2049 		phy->duplex == 1 ? "Full" : "Half",
2050 		phy->autoneg == 1 ? "" : "no ");
2051 }
2052 
2053 /**
2054  * spider_net_setup_phy - setup PHY
2055  * @card: card structure
2056  *
2057  * returns 0 on success, <0 on failure
2058  *
2059  * spider_net_setup_phy is used as part of spider_net_probe.
2060  **/
2061 static int
2062 spider_net_setup_phy(struct spider_net_card *card)
2063 {
2064 	struct mii_phy *phy = &card->phy;
2065 
2066 	spider_net_write_reg(card, SPIDER_NET_GDTDMASEL,
2067 			     SPIDER_NET_DMASEL_VALUE);
2068 	spider_net_write_reg(card, SPIDER_NET_GPCCTRL,
2069 			     SPIDER_NET_PHY_CTRL_VALUE);
2070 
2071 	phy->dev = card->netdev;
2072 	phy->mdio_read = spider_net_read_phy;
2073 	phy->mdio_write = spider_net_write_phy;
2074 
2075 	for (phy->mii_id = 1; phy->mii_id <= 31; phy->mii_id++) {
2076 		unsigned short id;
2077 		id = spider_net_read_phy(card->netdev, phy->mii_id, MII_BMSR);
2078 		if (id != 0x0000 && id != 0xffff) {
2079 			if (!sungem_phy_probe(phy, phy->mii_id)) {
2080 				pr_info("Found %s.\n", phy->def->name);
2081 				break;
2082 			}
2083 		}
2084 	}
2085 
2086 	return 0;
2087 }
2088 
2089 /**
2090  * spider_net_workaround_rxramfull - work around firmware bug
2091  * @card: card structure
2092  *
2093  * no return value
2094  **/
2095 static void
2096 spider_net_workaround_rxramfull(struct spider_net_card *card)
2097 {
2098 	int i, sequencer = 0;
2099 
2100 	/* cancel reset */
2101 	spider_net_write_reg(card, SPIDER_NET_CKRCTRL,
2102 			     SPIDER_NET_CKRCTRL_RUN_VALUE);
2103 
2104 	/* empty sequencer data */
2105 	for (sequencer = 0; sequencer < SPIDER_NET_FIRMWARE_SEQS;
2106 	     sequencer++) {
2107 		spider_net_write_reg(card, SPIDER_NET_GSnPRGADR +
2108 				     sequencer * 8, 0x0);
2109 		for (i = 0; i < SPIDER_NET_FIRMWARE_SEQWORDS; i++) {
2110 			spider_net_write_reg(card, SPIDER_NET_GSnPRGDAT +
2111 					     sequencer * 8, 0x0);
2112 		}
2113 	}
2114 
2115 	/* set sequencer operation */
2116 	spider_net_write_reg(card, SPIDER_NET_GSINIT, 0x000000fe);
2117 
2118 	/* reset */
2119 	spider_net_write_reg(card, SPIDER_NET_CKRCTRL,
2120 			     SPIDER_NET_CKRCTRL_STOP_VALUE);
2121 }
2122 
2123 /**
2124  * spider_net_stop - called upon ifconfig down
2125  * @netdev: interface device structure
2126  *
2127  * always returns 0
2128  */
2129 int
2130 spider_net_stop(struct net_device *netdev)
2131 {
2132 	struct spider_net_card *card = netdev_priv(netdev);
2133 
2134 	napi_disable(&card->napi);
2135 	netif_carrier_off(netdev);
2136 	netif_stop_queue(netdev);
2137 	del_timer_sync(&card->tx_timer);
2138 	del_timer_sync(&card->aneg_timer);
2139 
2140 	spider_net_disable_interrupts(card);
2141 
2142 	free_irq(netdev->irq, netdev);
2143 
2144 	spider_net_write_reg(card, SPIDER_NET_GDTDMACCNTR,
2145 			     SPIDER_NET_DMA_TX_FEND_VALUE);
2146 
2147 	/* turn off DMA, force end */
2148 	spider_net_disable_rxdmac(card);
2149 
2150 	/* release chains */
2151 	spider_net_release_tx_chain(card, 1);
2152 	spider_net_free_rx_chain_contents(card);
2153 
2154 	spider_net_free_chain(card, &card->tx_chain);
2155 	spider_net_free_chain(card, &card->rx_chain);
2156 
2157 	return 0;
2158 }
2159 
2160 /**
2161  * spider_net_tx_timeout_task - task scheduled by the watchdog timeout
2162  * function (to be called not under interrupt status)
2163  * @work: work context used to obtain the pointer to net card data structure
2164  *
2165  * called as task when tx hangs, resets interface (if interface is up)
2166  */
2167 static void
2168 spider_net_tx_timeout_task(struct work_struct *work)
2169 {
2170 	struct spider_net_card *card =
2171 		container_of(work, struct spider_net_card, tx_timeout_task);
2172 	struct net_device *netdev = card->netdev;
2173 
2174 	if (!(netdev->flags & IFF_UP))
2175 		goto out;
2176 
2177 	netif_device_detach(netdev);
2178 	spider_net_stop(netdev);
2179 
2180 	spider_net_workaround_rxramfull(card);
2181 	spider_net_init_card(card);
2182 
2183 	if (spider_net_setup_phy(card))
2184 		goto out;
2185 
2186 	spider_net_open(netdev);
2187 	spider_net_kick_tx_dma(card);
2188 	netif_device_attach(netdev);
2189 
2190 out:
2191 	atomic_dec(&card->tx_timeout_task_counter);
2192 }
2193 
2194 /**
2195  * spider_net_tx_timeout - called when the tx timeout watchdog kicks in.
2196  * @netdev: interface device structure
2197  * @txqueue: unused
2198  *
2199  * called, if tx hangs. Schedules a task that resets the interface
2200  */
2201 static void
2202 spider_net_tx_timeout(struct net_device *netdev, unsigned int txqueue)
2203 {
2204 	struct spider_net_card *card;
2205 
2206 	card = netdev_priv(netdev);
2207 	atomic_inc(&card->tx_timeout_task_counter);
2208 	if (netdev->flags & IFF_UP)
2209 		schedule_work(&card->tx_timeout_task);
2210 	else
2211 		atomic_dec(&card->tx_timeout_task_counter);
2212 	card->spider_stats.tx_timeouts++;
2213 }
2214 
2215 static const struct net_device_ops spider_net_ops = {
2216 	.ndo_open		= spider_net_open,
2217 	.ndo_stop		= spider_net_stop,
2218 	.ndo_start_xmit		= spider_net_xmit,
2219 	.ndo_set_rx_mode	= spider_net_set_multi,
2220 	.ndo_set_mac_address	= spider_net_set_mac,
2221 	.ndo_eth_ioctl		= spider_net_do_ioctl,
2222 	.ndo_tx_timeout		= spider_net_tx_timeout,
2223 	.ndo_validate_addr	= eth_validate_addr,
2224 	/* HW VLAN */
2225 #ifdef CONFIG_NET_POLL_CONTROLLER
2226 	/* poll controller */
2227 	.ndo_poll_controller	= spider_net_poll_controller,
2228 #endif /* CONFIG_NET_POLL_CONTROLLER */
2229 };
2230 
2231 /**
2232  * spider_net_setup_netdev_ops - initialization of net_device operations
2233  * @netdev: net_device structure
2234  *
2235  * fills out function pointers in the net_device structure
2236  */
2237 static void
2238 spider_net_setup_netdev_ops(struct net_device *netdev)
2239 {
2240 	netdev->netdev_ops = &spider_net_ops;
2241 	netdev->watchdog_timeo = SPIDER_NET_WATCHDOG_TIMEOUT;
2242 	/* ethtool ops */
2243 	netdev->ethtool_ops = &spider_net_ethtool_ops;
2244 }
2245 
2246 /**
2247  * spider_net_setup_netdev - initialization of net_device
2248  * @card: card structure
2249  *
2250  * Returns 0 on success or <0 on failure
2251  *
2252  * spider_net_setup_netdev initializes the net_device structure
2253  **/
2254 static int
2255 spider_net_setup_netdev(struct spider_net_card *card)
2256 {
2257 	int result;
2258 	struct net_device *netdev = card->netdev;
2259 	struct device_node *dn;
2260 	struct sockaddr addr;
2261 	const u8 *mac;
2262 
2263 	SET_NETDEV_DEV(netdev, &card->pdev->dev);
2264 
2265 	pci_set_drvdata(card->pdev, netdev);
2266 
2267 	timer_setup(&card->tx_timer, spider_net_cleanup_tx_ring, 0);
2268 	netdev->irq = card->pdev->irq;
2269 
2270 	card->aneg_count = 0;
2271 	timer_setup(&card->aneg_timer, spider_net_link_phy, 0);
2272 
2273 	netif_napi_add(netdev, &card->napi, spider_net_poll);
2274 
2275 	spider_net_setup_netdev_ops(netdev);
2276 
2277 	netdev->hw_features = NETIF_F_RXCSUM | NETIF_F_IP_CSUM;
2278 	if (SPIDER_NET_RX_CSUM_DEFAULT)
2279 		netdev->features |= NETIF_F_RXCSUM;
2280 	netdev->features |= NETIF_F_IP_CSUM;
2281 	/* some time: NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX |
2282 	 *		NETIF_F_HW_VLAN_CTAG_FILTER
2283 	 */
2284 	netdev->lltx = true;
2285 
2286 	/* MTU range: 64 - 2294 */
2287 	netdev->min_mtu = SPIDER_NET_MIN_MTU;
2288 	netdev->max_mtu = SPIDER_NET_MAX_MTU;
2289 
2290 	netdev->irq = card->pdev->irq;
2291 	card->num_rx_ints = 0;
2292 	card->ignore_rx_ramfull = 0;
2293 
2294 	dn = pci_device_to_OF_node(card->pdev);
2295 	if (!dn)
2296 		return -EIO;
2297 
2298 	mac = of_get_property(dn, "local-mac-address", NULL);
2299 	if (!mac)
2300 		return -EIO;
2301 	memcpy(addr.sa_data, mac, ETH_ALEN);
2302 
2303 	result = spider_net_set_mac(netdev, &addr);
2304 	if ((result) && (netif_msg_probe(card)))
2305 		dev_err(&card->netdev->dev,
2306 		        "Failed to set MAC address: %i\n", result);
2307 
2308 	result = register_netdev(netdev);
2309 	if (result) {
2310 		if (netif_msg_probe(card))
2311 			dev_err(&card->netdev->dev,
2312 			        "Couldn't register net_device: %i\n", result);
2313 		return result;
2314 	}
2315 
2316 	if (netif_msg_probe(card))
2317 		pr_info("Initialized device %s.\n", netdev->name);
2318 
2319 	return 0;
2320 }
2321 
2322 /**
2323  * spider_net_alloc_card - allocates net_device and card structure
2324  *
2325  * returns the card structure or NULL in case of errors
2326  *
2327  * the card and net_device structures are linked to each other
2328  */
2329 static struct spider_net_card *
2330 spider_net_alloc_card(void)
2331 {
2332 	struct net_device *netdev;
2333 	struct spider_net_card *card;
2334 
2335 	netdev = alloc_etherdev(struct_size(card, darray,
2336 					    size_add(tx_descriptors, rx_descriptors)));
2337 	if (!netdev)
2338 		return NULL;
2339 
2340 	card = netdev_priv(netdev);
2341 	card->netdev = netdev;
2342 	card->msg_enable = SPIDER_NET_DEFAULT_MSG;
2343 	INIT_WORK(&card->tx_timeout_task, spider_net_tx_timeout_task);
2344 	init_waitqueue_head(&card->waitq);
2345 	atomic_set(&card->tx_timeout_task_counter, 0);
2346 
2347 	card->rx_chain.num_desc = rx_descriptors;
2348 	card->rx_chain.ring = card->darray;
2349 	card->tx_chain.num_desc = tx_descriptors;
2350 	card->tx_chain.ring = card->darray + rx_descriptors;
2351 
2352 	return card;
2353 }
2354 
2355 /**
2356  * spider_net_undo_pci_setup - releases PCI ressources
2357  * @card: card structure
2358  *
2359  * spider_net_undo_pci_setup releases the mapped regions
2360  */
2361 static void
2362 spider_net_undo_pci_setup(struct spider_net_card *card)
2363 {
2364 	iounmap(card->regs);
2365 	pci_release_regions(card->pdev);
2366 }
2367 
2368 /**
2369  * spider_net_setup_pci_dev - sets up the device in terms of PCI operations
2370  * @pdev: PCI device
2371  *
2372  * Returns the card structure or NULL if any errors occur
2373  *
2374  * spider_net_setup_pci_dev initializes pdev and together with the
2375  * functions called in spider_net_open configures the device so that
2376  * data can be transferred over it
2377  * The net_device structure is attached to the card structure, if the
2378  * function returns without error.
2379  **/
2380 static struct spider_net_card *
2381 spider_net_setup_pci_dev(struct pci_dev *pdev)
2382 {
2383 	struct spider_net_card *card;
2384 	unsigned long mmio_start, mmio_len;
2385 
2386 	if (pci_enable_device(pdev)) {
2387 		dev_err(&pdev->dev, "Couldn't enable PCI device\n");
2388 		return NULL;
2389 	}
2390 
2391 	if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) {
2392 		dev_err(&pdev->dev,
2393 		        "Couldn't find proper PCI device base address.\n");
2394 		goto out_disable_dev;
2395 	}
2396 
2397 	if (pci_request_regions(pdev, spider_net_driver_name)) {
2398 		dev_err(&pdev->dev,
2399 		        "Couldn't obtain PCI resources, aborting.\n");
2400 		goto out_disable_dev;
2401 	}
2402 
2403 	pci_set_master(pdev);
2404 
2405 	card = spider_net_alloc_card();
2406 	if (!card) {
2407 		dev_err(&pdev->dev,
2408 		        "Couldn't allocate net_device structure, aborting.\n");
2409 		goto out_release_regions;
2410 	}
2411 	card->pdev = pdev;
2412 
2413 	/* fetch base address and length of first resource */
2414 	mmio_start = pci_resource_start(pdev, 0);
2415 	mmio_len = pci_resource_len(pdev, 0);
2416 
2417 	card->netdev->mem_start = mmio_start;
2418 	card->netdev->mem_end = mmio_start + mmio_len;
2419 	card->regs = ioremap(mmio_start, mmio_len);
2420 
2421 	if (!card->regs) {
2422 		dev_err(&pdev->dev,
2423 		        "Couldn't obtain PCI resources, aborting.\n");
2424 		goto out_release_regions;
2425 	}
2426 
2427 	return card;
2428 
2429 out_release_regions:
2430 	pci_release_regions(pdev);
2431 out_disable_dev:
2432 	pci_disable_device(pdev);
2433 	return NULL;
2434 }
2435 
2436 /**
2437  * spider_net_probe - initialization of a device
2438  * @pdev: PCI device
2439  * @ent: entry in the device id list
2440  *
2441  * Returns 0 on success, <0 on failure
2442  *
2443  * spider_net_probe initializes pdev and registers a net_device
2444  * structure for it. After that, the device can be ifconfig'ed up
2445  **/
2446 static int
2447 spider_net_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
2448 {
2449 	int err = -EIO;
2450 	struct spider_net_card *card;
2451 
2452 	card = spider_net_setup_pci_dev(pdev);
2453 	if (!card)
2454 		goto out;
2455 
2456 	spider_net_workaround_rxramfull(card);
2457 	spider_net_init_card(card);
2458 
2459 	err = spider_net_setup_phy(card);
2460 	if (err)
2461 		goto out_undo_pci;
2462 
2463 	err = spider_net_setup_netdev(card);
2464 	if (err)
2465 		goto out_undo_pci;
2466 
2467 	return 0;
2468 
2469 out_undo_pci:
2470 	spider_net_undo_pci_setup(card);
2471 	free_netdev(card->netdev);
2472 out:
2473 	return err;
2474 }
2475 
2476 /**
2477  * spider_net_remove - removal of a device
2478  * @pdev: PCI device
2479  *
2480  * Returns 0 on success, <0 on failure
2481  *
2482  * spider_net_remove is called to remove the device and unregisters the
2483  * net_device
2484  **/
2485 static void
2486 spider_net_remove(struct pci_dev *pdev)
2487 {
2488 	struct net_device *netdev;
2489 	struct spider_net_card *card;
2490 
2491 	netdev = pci_get_drvdata(pdev);
2492 	card = netdev_priv(netdev);
2493 
2494 	wait_event(card->waitq,
2495 		   atomic_read(&card->tx_timeout_task_counter) == 0);
2496 
2497 	unregister_netdev(netdev);
2498 
2499 	/* switch off card */
2500 	spider_net_write_reg(card, SPIDER_NET_CKRCTRL,
2501 			     SPIDER_NET_CKRCTRL_STOP_VALUE);
2502 	spider_net_write_reg(card, SPIDER_NET_CKRCTRL,
2503 			     SPIDER_NET_CKRCTRL_RUN_VALUE);
2504 
2505 	spider_net_undo_pci_setup(card);
2506 	free_netdev(netdev);
2507 }
2508 
2509 static struct pci_driver spider_net_driver = {
2510 	.name		= spider_net_driver_name,
2511 	.id_table	= spider_net_pci_tbl,
2512 	.probe		= spider_net_probe,
2513 	.remove		= spider_net_remove
2514 };
2515 
2516 /**
2517  * spider_net_init - init function when the driver is loaded
2518  *
2519  * spider_net_init registers the device driver
2520  */
2521 static int __init spider_net_init(void)
2522 {
2523 	printk(KERN_INFO "Spidernet version %s.\n", VERSION);
2524 
2525 	if (rx_descriptors < SPIDER_NET_RX_DESCRIPTORS_MIN) {
2526 		rx_descriptors = SPIDER_NET_RX_DESCRIPTORS_MIN;
2527 		pr_info("adjusting rx descriptors to %i.\n", rx_descriptors);
2528 	}
2529 	if (rx_descriptors > SPIDER_NET_RX_DESCRIPTORS_MAX) {
2530 		rx_descriptors = SPIDER_NET_RX_DESCRIPTORS_MAX;
2531 		pr_info("adjusting rx descriptors to %i.\n", rx_descriptors);
2532 	}
2533 	if (tx_descriptors < SPIDER_NET_TX_DESCRIPTORS_MIN) {
2534 		tx_descriptors = SPIDER_NET_TX_DESCRIPTORS_MIN;
2535 		pr_info("adjusting tx descriptors to %i.\n", tx_descriptors);
2536 	}
2537 	if (tx_descriptors > SPIDER_NET_TX_DESCRIPTORS_MAX) {
2538 		tx_descriptors = SPIDER_NET_TX_DESCRIPTORS_MAX;
2539 		pr_info("adjusting tx descriptors to %i.\n", tx_descriptors);
2540 	}
2541 
2542 	return pci_register_driver(&spider_net_driver);
2543 }
2544 
2545 /**
2546  * spider_net_cleanup - exit function when driver is unloaded
2547  *
2548  * spider_net_cleanup unregisters the device driver
2549  */
2550 static void __exit spider_net_cleanup(void)
2551 {
2552 	pci_unregister_driver(&spider_net_driver);
2553 }
2554 
2555 module_init(spider_net_init);
2556 module_exit(spider_net_cleanup);
2557