1 /*
2  * Faraday FTGMAC100 Gigabit Ethernet
3  *
4  * (C) Copyright 2009-2011 Faraday Technology
5  * Po-Yu Chuang <ratbert@faraday-tech.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21 
22 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
23 
24 #include <linux/dma-mapping.h>
25 #include <linux/etherdevice.h>
26 #include <linux/ethtool.h>
27 #include <linux/interrupt.h>
28 #include <linux/io.h>
29 #include <linux/module.h>
30 #include <linux/netdevice.h>
31 #include <linux/of.h>
32 #include <linux/phy.h>
33 #include <linux/platform_device.h>
34 #include <linux/property.h>
35 #include <net/ip.h>
36 #include <net/ncsi.h>
37 
38 #include "ftgmac100.h"
39 
40 #define DRV_NAME	"ftgmac100"
41 #define DRV_VERSION	"0.7"
42 
43 /* Arbitrary values, I am not sure the HW has limits */
44 #define MAX_RX_QUEUE_ENTRIES	1024
45 #define MAX_TX_QUEUE_ENTRIES	1024
46 #define MIN_RX_QUEUE_ENTRIES	32
47 #define MIN_TX_QUEUE_ENTRIES	32
48 
49 /* Defaults */
50 #define DEF_RX_QUEUE_ENTRIES	256
51 #define DEF_TX_QUEUE_ENTRIES	512
52 
53 #define MAX_PKT_SIZE		1536
54 #define RX_BUF_SIZE		MAX_PKT_SIZE	/* must be smaller than 0x3fff */
55 
56 /* Min number of tx ring entries before stopping queue */
57 #define TX_THRESHOLD		(MAX_SKB_FRAGS + 1)
58 
59 struct ftgmac100 {
60 	/* Registers */
61 	struct resource *res;
62 	void __iomem *base;
63 
64 	/* Rx ring */
65 	unsigned int rx_q_entries;
66 	struct ftgmac100_rxdes *rxdes;
67 	dma_addr_t rxdes_dma;
68 	struct sk_buff **rx_skbs;
69 	unsigned int rx_pointer;
70 	u32 rxdes0_edorr_mask;
71 
72 	/* Tx ring */
73 	unsigned int tx_q_entries;
74 	struct ftgmac100_txdes *txdes;
75 	dma_addr_t txdes_dma;
76 	struct sk_buff **tx_skbs;
77 	unsigned int tx_clean_pointer;
78 	unsigned int tx_pointer;
79 	u32 txdes0_edotr_mask;
80 
81 	/* Used to signal the reset task of ring change request */
82 	unsigned int new_rx_q_entries;
83 	unsigned int new_tx_q_entries;
84 
85 	/* Scratch page to use when rx skb alloc fails */
86 	void *rx_scratch;
87 	dma_addr_t rx_scratch_dma;
88 
89 	/* Component structures */
90 	struct net_device *netdev;
91 	struct device *dev;
92 	struct ncsi_dev *ndev;
93 	struct napi_struct napi;
94 	struct work_struct reset_task;
95 	struct mii_bus *mii_bus;
96 
97 	/* Link management */
98 	int cur_speed;
99 	int cur_duplex;
100 	bool use_ncsi;
101 
102 	/* Misc */
103 	bool need_mac_restart;
104 	bool is_aspeed;
105 };
106 
107 static int ftgmac100_reset_mac(struct ftgmac100 *priv, u32 maccr)
108 {
109 	struct net_device *netdev = priv->netdev;
110 	int i;
111 
112 	/* NOTE: reset clears all registers */
113 	iowrite32(maccr, priv->base + FTGMAC100_OFFSET_MACCR);
114 	iowrite32(maccr | FTGMAC100_MACCR_SW_RST,
115 		  priv->base + FTGMAC100_OFFSET_MACCR);
116 	for (i = 0; i < 50; i++) {
117 		unsigned int maccr;
118 
119 		maccr = ioread32(priv->base + FTGMAC100_OFFSET_MACCR);
120 		if (!(maccr & FTGMAC100_MACCR_SW_RST))
121 			return 0;
122 
123 		udelay(1);
124 	}
125 
126 	netdev_err(netdev, "Hardware reset failed\n");
127 	return -EIO;
128 }
129 
130 static int ftgmac100_reset_and_config_mac(struct ftgmac100 *priv)
131 {
132 	u32 maccr = 0;
133 
134 	switch (priv->cur_speed) {
135 	case SPEED_10:
136 	case 0: /* no link */
137 		break;
138 
139 	case SPEED_100:
140 		maccr |= FTGMAC100_MACCR_FAST_MODE;
141 		break;
142 
143 	case SPEED_1000:
144 		maccr |= FTGMAC100_MACCR_GIGA_MODE;
145 		break;
146 	default:
147 		netdev_err(priv->netdev, "Unknown speed %d !\n",
148 			   priv->cur_speed);
149 		break;
150 	}
151 
152 	/* (Re)initialize the queue pointers */
153 	priv->rx_pointer = 0;
154 	priv->tx_clean_pointer = 0;
155 	priv->tx_pointer = 0;
156 
157 	/* The doc says reset twice with 10us interval */
158 	if (ftgmac100_reset_mac(priv, maccr))
159 		return -EIO;
160 	usleep_range(10, 1000);
161 	return ftgmac100_reset_mac(priv, maccr);
162 }
163 
164 static void ftgmac100_write_mac_addr(struct ftgmac100 *priv, const u8 *mac)
165 {
166 	unsigned int maddr = mac[0] << 8 | mac[1];
167 	unsigned int laddr = mac[2] << 24 | mac[3] << 16 | mac[4] << 8 | mac[5];
168 
169 	iowrite32(maddr, priv->base + FTGMAC100_OFFSET_MAC_MADR);
170 	iowrite32(laddr, priv->base + FTGMAC100_OFFSET_MAC_LADR);
171 }
172 
173 static void ftgmac100_initial_mac(struct ftgmac100 *priv)
174 {
175 	u8 mac[ETH_ALEN];
176 	unsigned int m;
177 	unsigned int l;
178 	void *addr;
179 
180 	addr = device_get_mac_address(priv->dev, mac, ETH_ALEN);
181 	if (addr) {
182 		ether_addr_copy(priv->netdev->dev_addr, mac);
183 		dev_info(priv->dev, "Read MAC address %pM from device tree\n",
184 			 mac);
185 		return;
186 	}
187 
188 	m = ioread32(priv->base + FTGMAC100_OFFSET_MAC_MADR);
189 	l = ioread32(priv->base + FTGMAC100_OFFSET_MAC_LADR);
190 
191 	mac[0] = (m >> 8) & 0xff;
192 	mac[1] = m & 0xff;
193 	mac[2] = (l >> 24) & 0xff;
194 	mac[3] = (l >> 16) & 0xff;
195 	mac[4] = (l >> 8) & 0xff;
196 	mac[5] = l & 0xff;
197 
198 	if (is_valid_ether_addr(mac)) {
199 		ether_addr_copy(priv->netdev->dev_addr, mac);
200 		dev_info(priv->dev, "Read MAC address %pM from chip\n", mac);
201 	} else {
202 		eth_hw_addr_random(priv->netdev);
203 		dev_info(priv->dev, "Generated random MAC address %pM\n",
204 			 priv->netdev->dev_addr);
205 	}
206 }
207 
208 static int ftgmac100_set_mac_addr(struct net_device *dev, void *p)
209 {
210 	int ret;
211 
212 	ret = eth_prepare_mac_addr_change(dev, p);
213 	if (ret < 0)
214 		return ret;
215 
216 	eth_commit_mac_addr_change(dev, p);
217 	ftgmac100_write_mac_addr(netdev_priv(dev), dev->dev_addr);
218 
219 	return 0;
220 }
221 
222 static void ftgmac100_init_hw(struct ftgmac100 *priv)
223 {
224 	u32 reg, rfifo_sz, tfifo_sz;
225 
226 	/* Clear stale interrupts */
227 	reg = ioread32(priv->base + FTGMAC100_OFFSET_ISR);
228 	iowrite32(reg, priv->base + FTGMAC100_OFFSET_ISR);
229 
230 	/* Setup RX ring buffer base */
231 	iowrite32(priv->rxdes_dma, priv->base + FTGMAC100_OFFSET_RXR_BADR);
232 
233 	/* Setup TX ring buffer base */
234 	iowrite32(priv->txdes_dma, priv->base + FTGMAC100_OFFSET_NPTXR_BADR);
235 
236 	/* Configure RX buffer size */
237 	iowrite32(FTGMAC100_RBSR_SIZE(RX_BUF_SIZE),
238 		  priv->base + FTGMAC100_OFFSET_RBSR);
239 
240 	/* Set RX descriptor autopoll */
241 	iowrite32(FTGMAC100_APTC_RXPOLL_CNT(1),
242 		  priv->base + FTGMAC100_OFFSET_APTC);
243 
244 	/* Write MAC address */
245 	ftgmac100_write_mac_addr(priv, priv->netdev->dev_addr);
246 
247 	/* Configure descriptor sizes and increase burst sizes according
248 	 * to values in Aspeed SDK. The FIFO arbitration is enabled and
249 	 * the thresholds set based on the recommended values in the
250 	 * AST2400 specification.
251 	 */
252 	iowrite32(FTGMAC100_DBLAC_RXDES_SIZE(2) |   /* 2*8 bytes RX descs */
253 		  FTGMAC100_DBLAC_TXDES_SIZE(2) |   /* 2*8 bytes TX descs */
254 		  FTGMAC100_DBLAC_RXBURST_SIZE(3) | /* 512 bytes max RX bursts */
255 		  FTGMAC100_DBLAC_TXBURST_SIZE(3) | /* 512 bytes max TX bursts */
256 		  FTGMAC100_DBLAC_RX_THR_EN |       /* Enable fifo threshold arb */
257 		  FTGMAC100_DBLAC_RXFIFO_HTHR(6) |  /* 6/8 of FIFO high threshold */
258 		  FTGMAC100_DBLAC_RXFIFO_LTHR(2),   /* 2/8 of FIFO low threshold */
259 		  priv->base + FTGMAC100_OFFSET_DBLAC);
260 
261 	/* Interrupt mitigation configured for 1 interrupt/packet. HW interrupt
262 	 * mitigation doesn't seem to provide any benefit with NAPI so leave
263 	 * it at that.
264 	 */
265 	iowrite32(FTGMAC100_ITC_RXINT_THR(1) |
266 		  FTGMAC100_ITC_TXINT_THR(1),
267 		  priv->base + FTGMAC100_OFFSET_ITC);
268 
269 	/* Configure FIFO sizes in the TPAFCR register */
270 	reg = ioread32(priv->base + FTGMAC100_OFFSET_FEAR);
271 	rfifo_sz = reg & 0x00000007;
272 	tfifo_sz = (reg >> 3) & 0x00000007;
273 	reg = ioread32(priv->base + FTGMAC100_OFFSET_TPAFCR);
274 	reg &= ~0x3f000000;
275 	reg |= (tfifo_sz << 27);
276 	reg |= (rfifo_sz << 24);
277 	iowrite32(reg, priv->base + FTGMAC100_OFFSET_TPAFCR);
278 }
279 
280 static void ftgmac100_start_hw(struct ftgmac100 *priv)
281 {
282 	u32 maccr = ioread32(priv->base + FTGMAC100_OFFSET_MACCR);
283 
284 	/* Keep the original GMAC and FAST bits */
285 	maccr &= (FTGMAC100_MACCR_FAST_MODE | FTGMAC100_MACCR_GIGA_MODE);
286 
287 	/* Add all the main enable bits */
288 	maccr |= FTGMAC100_MACCR_TXDMA_EN	|
289 		 FTGMAC100_MACCR_RXDMA_EN	|
290 		 FTGMAC100_MACCR_TXMAC_EN	|
291 		 FTGMAC100_MACCR_RXMAC_EN	|
292 		 FTGMAC100_MACCR_CRC_APD	|
293 		 FTGMAC100_MACCR_PHY_LINK_LEVEL	|
294 		 FTGMAC100_MACCR_RX_RUNT	|
295 		 FTGMAC100_MACCR_RX_BROADPKT;
296 
297 	/* Add other bits as needed */
298 	if (priv->cur_duplex == DUPLEX_FULL)
299 		maccr |= FTGMAC100_MACCR_FULLDUP;
300 
301 	/* Hit the HW */
302 	iowrite32(maccr, priv->base + FTGMAC100_OFFSET_MACCR);
303 }
304 
305 static void ftgmac100_stop_hw(struct ftgmac100 *priv)
306 {
307 	iowrite32(0, priv->base + FTGMAC100_OFFSET_MACCR);
308 }
309 
310 static int ftgmac100_alloc_rx_buf(struct ftgmac100 *priv, unsigned int entry,
311 				  struct ftgmac100_rxdes *rxdes, gfp_t gfp)
312 {
313 	struct net_device *netdev = priv->netdev;
314 	struct sk_buff *skb;
315 	dma_addr_t map;
316 	int err;
317 
318 	skb = netdev_alloc_skb_ip_align(netdev, RX_BUF_SIZE);
319 	if (unlikely(!skb)) {
320 		if (net_ratelimit())
321 			netdev_warn(netdev, "failed to allocate rx skb\n");
322 		err = -ENOMEM;
323 		map = priv->rx_scratch_dma;
324 	} else {
325 		map = dma_map_single(priv->dev, skb->data, RX_BUF_SIZE,
326 				     DMA_FROM_DEVICE);
327 		if (unlikely(dma_mapping_error(priv->dev, map))) {
328 			if (net_ratelimit())
329 				netdev_err(netdev, "failed to map rx page\n");
330 			dev_kfree_skb_any(skb);
331 			map = priv->rx_scratch_dma;
332 			skb = NULL;
333 			err = -ENOMEM;
334 		}
335 	}
336 
337 	/* Store skb */
338 	priv->rx_skbs[entry] = skb;
339 
340 	/* Store DMA address into RX desc */
341 	rxdes->rxdes3 = cpu_to_le32(map);
342 
343 	/* Ensure the above is ordered vs clearing the OWN bit */
344 	dma_wmb();
345 
346 	/* Clean status (which resets own bit) */
347 	if (entry == (priv->rx_q_entries - 1))
348 		rxdes->rxdes0 = cpu_to_le32(priv->rxdes0_edorr_mask);
349 	else
350 		rxdes->rxdes0 = 0;
351 
352 	return 0;
353 }
354 
355 static unsigned int ftgmac100_next_rx_pointer(struct ftgmac100 *priv,
356 					      unsigned int pointer)
357 {
358 	return (pointer + 1) & (priv->rx_q_entries - 1);
359 }
360 
361 static void ftgmac100_rx_packet_error(struct ftgmac100 *priv, u32 status)
362 {
363 	struct net_device *netdev = priv->netdev;
364 
365 	if (status & FTGMAC100_RXDES0_RX_ERR)
366 		netdev->stats.rx_errors++;
367 
368 	if (status & FTGMAC100_RXDES0_CRC_ERR)
369 		netdev->stats.rx_crc_errors++;
370 
371 	if (status & (FTGMAC100_RXDES0_FTL |
372 		      FTGMAC100_RXDES0_RUNT |
373 		      FTGMAC100_RXDES0_RX_ODD_NB))
374 		netdev->stats.rx_length_errors++;
375 }
376 
377 static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
378 {
379 	struct net_device *netdev = priv->netdev;
380 	struct ftgmac100_rxdes *rxdes;
381 	struct sk_buff *skb;
382 	unsigned int pointer, size;
383 	u32 status, csum_vlan;
384 	dma_addr_t map;
385 
386 	/* Grab next RX descriptor */
387 	pointer = priv->rx_pointer;
388 	rxdes = &priv->rxdes[pointer];
389 
390 	/* Grab descriptor status */
391 	status = le32_to_cpu(rxdes->rxdes0);
392 
393 	/* Do we have a packet ? */
394 	if (!(status & FTGMAC100_RXDES0_RXPKT_RDY))
395 		return false;
396 
397 	/* Order subsequent reads with the test for the ready bit */
398 	dma_rmb();
399 
400 	/* We don't cope with fragmented RX packets */
401 	if (unlikely(!(status & FTGMAC100_RXDES0_FRS) ||
402 		     !(status & FTGMAC100_RXDES0_LRS)))
403 		goto drop;
404 
405 	/* Grab received size and csum vlan field in the descriptor */
406 	size = status & FTGMAC100_RXDES0_VDBC;
407 	csum_vlan = le32_to_cpu(rxdes->rxdes1);
408 
409 	/* Any error (other than csum offload) flagged ? */
410 	if (unlikely(status & RXDES0_ANY_ERROR)) {
411 		/* Correct for incorrect flagging of runt packets
412 		 * with vlan tags... Just accept a runt packet that
413 		 * has been flagged as vlan and whose size is at
414 		 * least 60 bytes.
415 		 */
416 		if ((status & FTGMAC100_RXDES0_RUNT) &&
417 		    (csum_vlan & FTGMAC100_RXDES1_VLANTAG_AVAIL) &&
418 		    (size >= 60))
419 			status &= ~FTGMAC100_RXDES0_RUNT;
420 
421 		/* Any error still in there ? */
422 		if (status & RXDES0_ANY_ERROR) {
423 			ftgmac100_rx_packet_error(priv, status);
424 			goto drop;
425 		}
426 	}
427 
428 	/* If the packet had no skb (failed to allocate earlier)
429 	 * then try to allocate one and skip
430 	 */
431 	skb = priv->rx_skbs[pointer];
432 	if (!unlikely(skb)) {
433 		ftgmac100_alloc_rx_buf(priv, pointer, rxdes, GFP_ATOMIC);
434 		goto drop;
435 	}
436 
437 	if (unlikely(status & FTGMAC100_RXDES0_MULTICAST))
438 		netdev->stats.multicast++;
439 
440 	/* If the HW found checksum errors, bounce it to software.
441 	 *
442 	 * If we didn't, we need to see if the packet was recognized
443 	 * by HW as one of the supported checksummed protocols before
444 	 * we accept the HW test results.
445 	 */
446 	if (netdev->features & NETIF_F_RXCSUM) {
447 		u32 err_bits = FTGMAC100_RXDES1_TCP_CHKSUM_ERR |
448 			FTGMAC100_RXDES1_UDP_CHKSUM_ERR |
449 			FTGMAC100_RXDES1_IP_CHKSUM_ERR;
450 		if ((csum_vlan & err_bits) ||
451 		    !(csum_vlan & FTGMAC100_RXDES1_PROT_MASK))
452 			skb->ip_summed = CHECKSUM_NONE;
453 		else
454 			skb->ip_summed = CHECKSUM_UNNECESSARY;
455 	}
456 
457 	/* Transfer received size to skb */
458 	skb_put(skb, size);
459 
460 	/* Tear down DMA mapping, do necessary cache management */
461 	map = le32_to_cpu(rxdes->rxdes3);
462 
463 #if defined(CONFIG_ARM) && !defined(CONFIG_ARM_DMA_USE_IOMMU)
464 	/* When we don't have an iommu, we can save cycles by not
465 	 * invalidating the cache for the part of the packet that
466 	 * wasn't received.
467 	 */
468 	dma_unmap_single(priv->dev, map, size, DMA_FROM_DEVICE);
469 #else
470 	dma_unmap_single(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
471 #endif
472 
473 
474 	/* Resplenish rx ring */
475 	ftgmac100_alloc_rx_buf(priv, pointer, rxdes, GFP_ATOMIC);
476 	priv->rx_pointer = ftgmac100_next_rx_pointer(priv, pointer);
477 
478 	skb->protocol = eth_type_trans(skb, netdev);
479 
480 	netdev->stats.rx_packets++;
481 	netdev->stats.rx_bytes += size;
482 
483 	/* push packet to protocol stack */
484 	if (skb->ip_summed == CHECKSUM_NONE)
485 		netif_receive_skb(skb);
486 	else
487 		napi_gro_receive(&priv->napi, skb);
488 
489 	(*processed)++;
490 	return true;
491 
492  drop:
493 	/* Clean rxdes0 (which resets own bit) */
494 	rxdes->rxdes0 = cpu_to_le32(status & priv->rxdes0_edorr_mask);
495 	priv->rx_pointer = ftgmac100_next_rx_pointer(priv, pointer);
496 	netdev->stats.rx_dropped++;
497 	return true;
498 }
499 
500 static u32 ftgmac100_base_tx_ctlstat(struct ftgmac100 *priv,
501 				     unsigned int index)
502 {
503 	if (index == (priv->tx_q_entries - 1))
504 		return priv->txdes0_edotr_mask;
505 	else
506 		return 0;
507 }
508 
509 static unsigned int ftgmac100_next_tx_pointer(struct ftgmac100 *priv,
510 					      unsigned int pointer)
511 {
512 	return (pointer + 1) & (priv->tx_q_entries - 1);
513 }
514 
515 static u32 ftgmac100_tx_buf_avail(struct ftgmac100 *priv)
516 {
517 	/* Returns the number of available slots in the TX queue
518 	 *
519 	 * This always leaves one free slot so we don't have to
520 	 * worry about empty vs. full, and this simplifies the
521 	 * test for ftgmac100_tx_buf_cleanable() below
522 	 */
523 	return (priv->tx_clean_pointer - priv->tx_pointer - 1) &
524 		(priv->tx_q_entries - 1);
525 }
526 
527 static bool ftgmac100_tx_buf_cleanable(struct ftgmac100 *priv)
528 {
529 	return priv->tx_pointer != priv->tx_clean_pointer;
530 }
531 
532 static void ftgmac100_free_tx_packet(struct ftgmac100 *priv,
533 				     unsigned int pointer,
534 				     struct sk_buff *skb,
535 				     struct ftgmac100_txdes *txdes,
536 				     u32 ctl_stat)
537 {
538 	dma_addr_t map = le32_to_cpu(txdes->txdes3);
539 	size_t len;
540 
541 	if (ctl_stat & FTGMAC100_TXDES0_FTS) {
542 		len = skb_headlen(skb);
543 		dma_unmap_single(priv->dev, map, len, DMA_TO_DEVICE);
544 	} else {
545 		len = FTGMAC100_TXDES0_TXBUF_SIZE(ctl_stat);
546 		dma_unmap_page(priv->dev, map, len, DMA_TO_DEVICE);
547 	}
548 
549 	/* Free SKB on last segment */
550 	if (ctl_stat & FTGMAC100_TXDES0_LTS)
551 		dev_kfree_skb(skb);
552 	priv->tx_skbs[pointer] = NULL;
553 }
554 
555 static bool ftgmac100_tx_complete_packet(struct ftgmac100 *priv)
556 {
557 	struct net_device *netdev = priv->netdev;
558 	struct ftgmac100_txdes *txdes;
559 	struct sk_buff *skb;
560 	unsigned int pointer;
561 	u32 ctl_stat;
562 
563 	pointer = priv->tx_clean_pointer;
564 	txdes = &priv->txdes[pointer];
565 
566 	ctl_stat = le32_to_cpu(txdes->txdes0);
567 	if (ctl_stat & FTGMAC100_TXDES0_TXDMA_OWN)
568 		return false;
569 
570 	skb = priv->tx_skbs[pointer];
571 	netdev->stats.tx_packets++;
572 	netdev->stats.tx_bytes += skb->len;
573 	ftgmac100_free_tx_packet(priv, pointer, skb, txdes, ctl_stat);
574 	txdes->txdes0 = cpu_to_le32(ctl_stat & priv->txdes0_edotr_mask);
575 
576 	priv->tx_clean_pointer = ftgmac100_next_tx_pointer(priv, pointer);
577 
578 	return true;
579 }
580 
581 static void ftgmac100_tx_complete(struct ftgmac100 *priv)
582 {
583 	struct net_device *netdev = priv->netdev;
584 
585 	/* Process all completed packets */
586 	while (ftgmac100_tx_buf_cleanable(priv) &&
587 	       ftgmac100_tx_complete_packet(priv))
588 		;
589 
590 	/* Restart queue if needed */
591 	smp_mb();
592 	if (unlikely(netif_queue_stopped(netdev) &&
593 		     ftgmac100_tx_buf_avail(priv) >= TX_THRESHOLD)) {
594 		struct netdev_queue *txq;
595 
596 		txq = netdev_get_tx_queue(netdev, 0);
597 		__netif_tx_lock(txq, smp_processor_id());
598 		if (netif_queue_stopped(netdev) &&
599 		    ftgmac100_tx_buf_avail(priv) >= TX_THRESHOLD)
600 			netif_wake_queue(netdev);
601 		__netif_tx_unlock(txq);
602 	}
603 }
604 
605 static bool ftgmac100_prep_tx_csum(struct sk_buff *skb, u32 *csum_vlan)
606 {
607 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
608 		u8 ip_proto = ip_hdr(skb)->protocol;
609 
610 		*csum_vlan |= FTGMAC100_TXDES1_IP_CHKSUM;
611 		switch(ip_proto) {
612 		case IPPROTO_TCP:
613 			*csum_vlan |= FTGMAC100_TXDES1_TCP_CHKSUM;
614 			return true;
615 		case IPPROTO_UDP:
616 			*csum_vlan |= FTGMAC100_TXDES1_UDP_CHKSUM;
617 			return true;
618 		case IPPROTO_IP:
619 			return true;
620 		}
621 	}
622 	return skb_checksum_help(skb) == 0;
623 }
624 
625 static int ftgmac100_hard_start_xmit(struct sk_buff *skb,
626 				     struct net_device *netdev)
627 {
628 	struct ftgmac100 *priv = netdev_priv(netdev);
629 	struct ftgmac100_txdes *txdes, *first;
630 	unsigned int pointer, nfrags, len, i, j;
631 	u32 f_ctl_stat, ctl_stat, csum_vlan;
632 	dma_addr_t map;
633 
634 	/* The HW doesn't pad small frames */
635 	if (eth_skb_pad(skb)) {
636 		netdev->stats.tx_dropped++;
637 		return NETDEV_TX_OK;
638 	}
639 
640 	/* Reject oversize packets */
641 	if (unlikely(skb->len > MAX_PKT_SIZE)) {
642 		if (net_ratelimit())
643 			netdev_dbg(netdev, "tx packet too big\n");
644 		goto drop;
645 	}
646 
647 	/* Do we have a limit on #fragments ? I yet have to get a reply
648 	 * from Aspeed. If there's one I haven't hit it.
649 	 */
650 	nfrags = skb_shinfo(skb)->nr_frags;
651 
652 	/* Get header len */
653 	len = skb_headlen(skb);
654 
655 	/* Map the packet head */
656 	map = dma_map_single(priv->dev, skb->data, len, DMA_TO_DEVICE);
657 	if (dma_mapping_error(priv->dev, map)) {
658 		if (net_ratelimit())
659 			netdev_err(netdev, "map tx packet head failed\n");
660 		goto drop;
661 	}
662 
663 	/* Grab the next free tx descriptor */
664 	pointer = priv->tx_pointer;
665 	txdes = first = &priv->txdes[pointer];
666 
667 	/* Setup it up with the packet head. Don't write the head to the
668 	 * ring just yet
669 	 */
670 	priv->tx_skbs[pointer] = skb;
671 	f_ctl_stat = ftgmac100_base_tx_ctlstat(priv, pointer);
672 	f_ctl_stat |= FTGMAC100_TXDES0_TXDMA_OWN;
673 	f_ctl_stat |= FTGMAC100_TXDES0_TXBUF_SIZE(len);
674 	f_ctl_stat |= FTGMAC100_TXDES0_FTS;
675 	if (nfrags == 0)
676 		f_ctl_stat |= FTGMAC100_TXDES0_LTS;
677 	txdes->txdes3 = cpu_to_le32(map);
678 
679 	/* Setup HW checksumming */
680 	csum_vlan = 0;
681 	if (skb->ip_summed == CHECKSUM_PARTIAL &&
682 	    !ftgmac100_prep_tx_csum(skb, &csum_vlan))
683 		goto drop;
684 	txdes->txdes1 = cpu_to_le32(csum_vlan);
685 
686 	/* Next descriptor */
687 	pointer = ftgmac100_next_tx_pointer(priv, pointer);
688 
689 	/* Add the fragments */
690 	for (i = 0; i < nfrags; i++) {
691 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
692 
693 		len = frag->size;
694 
695 		/* Map it */
696 		map = skb_frag_dma_map(priv->dev, frag, 0, len,
697 				       DMA_TO_DEVICE);
698 		if (dma_mapping_error(priv->dev, map))
699 			goto dma_err;
700 
701 		/* Setup descriptor */
702 		priv->tx_skbs[pointer] = skb;
703 		txdes = &priv->txdes[pointer];
704 		ctl_stat = ftgmac100_base_tx_ctlstat(priv, pointer);
705 		ctl_stat |= FTGMAC100_TXDES0_TXDMA_OWN;
706 		ctl_stat |= FTGMAC100_TXDES0_TXBUF_SIZE(len);
707 		if (i == (nfrags - 1))
708 			ctl_stat |= FTGMAC100_TXDES0_LTS;
709 		txdes->txdes0 = cpu_to_le32(ctl_stat);
710 		txdes->txdes1 = 0;
711 		txdes->txdes3 = cpu_to_le32(map);
712 
713 		/* Next one */
714 		pointer = ftgmac100_next_tx_pointer(priv, pointer);
715 	}
716 
717 	/* Order the previous packet and descriptor udpates
718 	 * before setting the OWN bit on the first descriptor.
719 	 */
720 	dma_wmb();
721 	first->txdes0 = cpu_to_le32(f_ctl_stat);
722 
723 	/* Update next TX pointer */
724 	priv->tx_pointer = pointer;
725 
726 	/* If there isn't enough room for all the fragments of a new packet
727 	 * in the TX ring, stop the queue. The sequence below is race free
728 	 * vs. a concurrent restart in ftgmac100_poll()
729 	 */
730 	if (unlikely(ftgmac100_tx_buf_avail(priv) < TX_THRESHOLD)) {
731 		netif_stop_queue(netdev);
732 		/* Order the queue stop with the test below */
733 		smp_mb();
734 		if (ftgmac100_tx_buf_avail(priv) >= TX_THRESHOLD)
735 			netif_wake_queue(netdev);
736 	}
737 
738 	/* Poke transmitter to read the updated TX descriptors */
739 	iowrite32(1, priv->base + FTGMAC100_OFFSET_NPTXPD);
740 
741 	return NETDEV_TX_OK;
742 
743  dma_err:
744 	if (net_ratelimit())
745 		netdev_err(netdev, "map tx fragment failed\n");
746 
747 	/* Free head */
748 	pointer = priv->tx_pointer;
749 	ftgmac100_free_tx_packet(priv, pointer, skb, first, f_ctl_stat);
750 	first->txdes0 = cpu_to_le32(f_ctl_stat & priv->txdes0_edotr_mask);
751 
752 	/* Then all fragments */
753 	for (j = 0; j < i; j++) {
754 		pointer = ftgmac100_next_tx_pointer(priv, pointer);
755 		txdes = &priv->txdes[pointer];
756 		ctl_stat = le32_to_cpu(txdes->txdes0);
757 		ftgmac100_free_tx_packet(priv, pointer, skb, txdes, ctl_stat);
758 		txdes->txdes0 = cpu_to_le32(ctl_stat & priv->txdes0_edotr_mask);
759 	}
760 
761 	/* This cannot be reached if we successfully mapped the
762 	 * last fragment, so we know ftgmac100_free_tx_packet()
763 	 * hasn't freed the skb yet.
764 	 */
765  drop:
766 	/* Drop the packet */
767 	dev_kfree_skb_any(skb);
768 	netdev->stats.tx_dropped++;
769 
770 	return NETDEV_TX_OK;
771 }
772 
773 static void ftgmac100_free_buffers(struct ftgmac100 *priv)
774 {
775 	int i;
776 
777 	/* Free all RX buffers */
778 	for (i = 0; i < priv->rx_q_entries; i++) {
779 		struct ftgmac100_rxdes *rxdes = &priv->rxdes[i];
780 		struct sk_buff *skb = priv->rx_skbs[i];
781 		dma_addr_t map = le32_to_cpu(rxdes->rxdes3);
782 
783 		if (!skb)
784 			continue;
785 
786 		priv->rx_skbs[i] = NULL;
787 		dma_unmap_single(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
788 		dev_kfree_skb_any(skb);
789 	}
790 
791 	/* Free all TX buffers */
792 	for (i = 0; i < priv->tx_q_entries; i++) {
793 		struct ftgmac100_txdes *txdes = &priv->txdes[i];
794 		struct sk_buff *skb = priv->tx_skbs[i];
795 
796 		if (!skb)
797 			continue;
798 		ftgmac100_free_tx_packet(priv, i, skb, txdes,
799 					 le32_to_cpu(txdes->txdes0));
800 	}
801 }
802 
803 static void ftgmac100_free_rings(struct ftgmac100 *priv)
804 {
805 	/* Free skb arrays */
806 	kfree(priv->rx_skbs);
807 	kfree(priv->tx_skbs);
808 
809 	/* Free descriptors */
810 	if (priv->rxdes)
811 		dma_free_coherent(priv->dev, MAX_RX_QUEUE_ENTRIES *
812 				  sizeof(struct ftgmac100_rxdes),
813 				  priv->rxdes, priv->rxdes_dma);
814 	priv->rxdes = NULL;
815 
816 	if (priv->txdes)
817 		dma_free_coherent(priv->dev, MAX_TX_QUEUE_ENTRIES *
818 				  sizeof(struct ftgmac100_txdes),
819 				  priv->txdes, priv->txdes_dma);
820 	priv->txdes = NULL;
821 
822 	/* Free scratch packet buffer */
823 	if (priv->rx_scratch)
824 		dma_free_coherent(priv->dev, RX_BUF_SIZE,
825 				  priv->rx_scratch, priv->rx_scratch_dma);
826 }
827 
828 static int ftgmac100_alloc_rings(struct ftgmac100 *priv)
829 {
830 	/* Allocate skb arrays */
831 	priv->rx_skbs = kcalloc(MAX_RX_QUEUE_ENTRIES, sizeof(void *),
832 				GFP_KERNEL);
833 	if (!priv->rx_skbs)
834 		return -ENOMEM;
835 	priv->tx_skbs = kcalloc(MAX_TX_QUEUE_ENTRIES, sizeof(void *),
836 				GFP_KERNEL);
837 	if (!priv->tx_skbs)
838 		return -ENOMEM;
839 
840 	/* Allocate descriptors */
841 	priv->rxdes = dma_zalloc_coherent(priv->dev,
842 					  MAX_RX_QUEUE_ENTRIES *
843 					  sizeof(struct ftgmac100_rxdes),
844 					  &priv->rxdes_dma, GFP_KERNEL);
845 	if (!priv->rxdes)
846 		return -ENOMEM;
847 	priv->txdes = dma_zalloc_coherent(priv->dev,
848 					  MAX_TX_QUEUE_ENTRIES *
849 					  sizeof(struct ftgmac100_txdes),
850 					  &priv->txdes_dma, GFP_KERNEL);
851 	if (!priv->txdes)
852 		return -ENOMEM;
853 
854 	/* Allocate scratch packet buffer */
855 	priv->rx_scratch = dma_alloc_coherent(priv->dev,
856 					      RX_BUF_SIZE,
857 					      &priv->rx_scratch_dma,
858 					      GFP_KERNEL);
859 	if (!priv->rx_scratch)
860 		return -ENOMEM;
861 
862 	return 0;
863 }
864 
865 static void ftgmac100_init_rings(struct ftgmac100 *priv)
866 {
867 	struct ftgmac100_rxdes *rxdes = NULL;
868 	struct ftgmac100_txdes *txdes = NULL;
869 	int i;
870 
871 	/* Update entries counts */
872 	priv->rx_q_entries = priv->new_rx_q_entries;
873 	priv->tx_q_entries = priv->new_tx_q_entries;
874 
875 	if (WARN_ON(priv->rx_q_entries < MIN_RX_QUEUE_ENTRIES))
876 		return;
877 
878 	/* Initialize RX ring */
879 	for (i = 0; i < priv->rx_q_entries; i++) {
880 		rxdes = &priv->rxdes[i];
881 		rxdes->rxdes0 = 0;
882 		rxdes->rxdes3 = cpu_to_le32(priv->rx_scratch_dma);
883 	}
884 	/* Mark the end of the ring */
885 	rxdes->rxdes0 |= cpu_to_le32(priv->rxdes0_edorr_mask);
886 
887 	if (WARN_ON(priv->tx_q_entries < MIN_RX_QUEUE_ENTRIES))
888 		return;
889 
890 	/* Initialize TX ring */
891 	for (i = 0; i < priv->tx_q_entries; i++) {
892 		txdes = &priv->txdes[i];
893 		txdes->txdes0 = 0;
894 	}
895 	txdes->txdes0 |= cpu_to_le32(priv->txdes0_edotr_mask);
896 }
897 
898 static int ftgmac100_alloc_rx_buffers(struct ftgmac100 *priv)
899 {
900 	int i;
901 
902 	for (i = 0; i < priv->rx_q_entries; i++) {
903 		struct ftgmac100_rxdes *rxdes = &priv->rxdes[i];
904 
905 		if (ftgmac100_alloc_rx_buf(priv, i, rxdes, GFP_KERNEL))
906 			return -ENOMEM;
907 	}
908 	return 0;
909 }
910 
911 static void ftgmac100_adjust_link(struct net_device *netdev)
912 {
913 	struct ftgmac100 *priv = netdev_priv(netdev);
914 	struct phy_device *phydev = netdev->phydev;
915 	int new_speed;
916 
917 	/* We store "no link" as speed 0 */
918 	if (!phydev->link)
919 		new_speed = 0;
920 	else
921 		new_speed = phydev->speed;
922 
923 	if (phydev->speed == priv->cur_speed &&
924 	    phydev->duplex == priv->cur_duplex)
925 		return;
926 
927 	/* Print status if we have a link or we had one and just lost it,
928 	 * don't print otherwise.
929 	 */
930 	if (new_speed || priv->cur_speed)
931 		phy_print_status(phydev);
932 
933 	priv->cur_speed = new_speed;
934 	priv->cur_duplex = phydev->duplex;
935 
936 	/* Link is down, do nothing else */
937 	if (!new_speed)
938 		return;
939 
940 	/* Disable all interrupts */
941 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
942 
943 	/* Reset the adapter asynchronously */
944 	schedule_work(&priv->reset_task);
945 }
946 
947 static int ftgmac100_mii_probe(struct ftgmac100 *priv)
948 {
949 	struct net_device *netdev = priv->netdev;
950 	struct phy_device *phydev;
951 
952 	phydev = phy_find_first(priv->mii_bus);
953 	if (!phydev) {
954 		netdev_info(netdev, "%s: no PHY found\n", netdev->name);
955 		return -ENODEV;
956 	}
957 
958 	phydev = phy_connect(netdev, phydev_name(phydev),
959 			     &ftgmac100_adjust_link, PHY_INTERFACE_MODE_GMII);
960 
961 	if (IS_ERR(phydev)) {
962 		netdev_err(netdev, "%s: Could not attach to PHY\n", netdev->name);
963 		return PTR_ERR(phydev);
964 	}
965 
966 	return 0;
967 }
968 
969 static int ftgmac100_mdiobus_read(struct mii_bus *bus, int phy_addr, int regnum)
970 {
971 	struct net_device *netdev = bus->priv;
972 	struct ftgmac100 *priv = netdev_priv(netdev);
973 	unsigned int phycr;
974 	int i;
975 
976 	phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
977 
978 	/* preserve MDC cycle threshold */
979 	phycr &= FTGMAC100_PHYCR_MDC_CYCTHR_MASK;
980 
981 	phycr |= FTGMAC100_PHYCR_PHYAD(phy_addr) |
982 		 FTGMAC100_PHYCR_REGAD(regnum) |
983 		 FTGMAC100_PHYCR_MIIRD;
984 
985 	iowrite32(phycr, priv->base + FTGMAC100_OFFSET_PHYCR);
986 
987 	for (i = 0; i < 10; i++) {
988 		phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
989 
990 		if ((phycr & FTGMAC100_PHYCR_MIIRD) == 0) {
991 			int data;
992 
993 			data = ioread32(priv->base + FTGMAC100_OFFSET_PHYDATA);
994 			return FTGMAC100_PHYDATA_MIIRDATA(data);
995 		}
996 
997 		udelay(100);
998 	}
999 
1000 	netdev_err(netdev, "mdio read timed out\n");
1001 	return -EIO;
1002 }
1003 
1004 static int ftgmac100_mdiobus_write(struct mii_bus *bus, int phy_addr,
1005 				   int regnum, u16 value)
1006 {
1007 	struct net_device *netdev = bus->priv;
1008 	struct ftgmac100 *priv = netdev_priv(netdev);
1009 	unsigned int phycr;
1010 	int data;
1011 	int i;
1012 
1013 	phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
1014 
1015 	/* preserve MDC cycle threshold */
1016 	phycr &= FTGMAC100_PHYCR_MDC_CYCTHR_MASK;
1017 
1018 	phycr |= FTGMAC100_PHYCR_PHYAD(phy_addr) |
1019 		 FTGMAC100_PHYCR_REGAD(regnum) |
1020 		 FTGMAC100_PHYCR_MIIWR;
1021 
1022 	data = FTGMAC100_PHYDATA_MIIWDATA(value);
1023 
1024 	iowrite32(data, priv->base + FTGMAC100_OFFSET_PHYDATA);
1025 	iowrite32(phycr, priv->base + FTGMAC100_OFFSET_PHYCR);
1026 
1027 	for (i = 0; i < 10; i++) {
1028 		phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
1029 
1030 		if ((phycr & FTGMAC100_PHYCR_MIIWR) == 0)
1031 			return 0;
1032 
1033 		udelay(100);
1034 	}
1035 
1036 	netdev_err(netdev, "mdio write timed out\n");
1037 	return -EIO;
1038 }
1039 
1040 static void ftgmac100_get_drvinfo(struct net_device *netdev,
1041 				  struct ethtool_drvinfo *info)
1042 {
1043 	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
1044 	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
1045 	strlcpy(info->bus_info, dev_name(&netdev->dev), sizeof(info->bus_info));
1046 }
1047 
1048 static int ftgmac100_nway_reset(struct net_device *ndev)
1049 {
1050 	if (!ndev->phydev)
1051 		return -ENXIO;
1052 	return phy_start_aneg(ndev->phydev);
1053 }
1054 
1055 static void ftgmac100_get_ringparam(struct net_device *netdev,
1056 				    struct ethtool_ringparam *ering)
1057 {
1058 	struct ftgmac100 *priv = netdev_priv(netdev);
1059 
1060 	memset(ering, 0, sizeof(*ering));
1061 	ering->rx_max_pending = MAX_RX_QUEUE_ENTRIES;
1062 	ering->tx_max_pending = MAX_TX_QUEUE_ENTRIES;
1063 	ering->rx_pending = priv->rx_q_entries;
1064 	ering->tx_pending = priv->tx_q_entries;
1065 }
1066 
1067 static int ftgmac100_set_ringparam(struct net_device *netdev,
1068 				   struct ethtool_ringparam *ering)
1069 {
1070 	struct ftgmac100 *priv = netdev_priv(netdev);
1071 
1072 	if (ering->rx_pending > MAX_RX_QUEUE_ENTRIES ||
1073 	    ering->tx_pending > MAX_TX_QUEUE_ENTRIES ||
1074 	    ering->rx_pending < MIN_RX_QUEUE_ENTRIES ||
1075 	    ering->tx_pending < MIN_TX_QUEUE_ENTRIES ||
1076 	    !is_power_of_2(ering->rx_pending) ||
1077 	    !is_power_of_2(ering->tx_pending))
1078 		return -EINVAL;
1079 
1080 	priv->new_rx_q_entries = ering->rx_pending;
1081 	priv->new_tx_q_entries = ering->tx_pending;
1082 	if (netif_running(netdev))
1083 		schedule_work(&priv->reset_task);
1084 
1085 	return 0;
1086 }
1087 
1088 static const struct ethtool_ops ftgmac100_ethtool_ops = {
1089 	.get_drvinfo		= ftgmac100_get_drvinfo,
1090 	.get_link		= ethtool_op_get_link,
1091 	.get_link_ksettings	= phy_ethtool_get_link_ksettings,
1092 	.set_link_ksettings	= phy_ethtool_set_link_ksettings,
1093 	.get_ringparam		= ftgmac100_get_ringparam,
1094 	.set_ringparam		= ftgmac100_set_ringparam,
1095 };
1096 
1097 static irqreturn_t ftgmac100_interrupt(int irq, void *dev_id)
1098 {
1099 	struct net_device *netdev = dev_id;
1100 	struct ftgmac100 *priv = netdev_priv(netdev);
1101 	unsigned int status, new_mask = FTGMAC100_INT_BAD;
1102 
1103 	/* Fetch and clear interrupt bits, process abnormal ones */
1104 	status = ioread32(priv->base + FTGMAC100_OFFSET_ISR);
1105 	iowrite32(status, priv->base + FTGMAC100_OFFSET_ISR);
1106 	if (unlikely(status & FTGMAC100_INT_BAD)) {
1107 
1108 		/* RX buffer unavailable */
1109 		if (status & FTGMAC100_INT_NO_RXBUF)
1110 			netdev->stats.rx_over_errors++;
1111 
1112 		/* received packet lost due to RX FIFO full */
1113 		if (status & FTGMAC100_INT_RPKT_LOST)
1114 			netdev->stats.rx_fifo_errors++;
1115 
1116 		/* sent packet lost due to excessive TX collision */
1117 		if (status & FTGMAC100_INT_XPKT_LOST)
1118 			netdev->stats.tx_fifo_errors++;
1119 
1120 		/* AHB error -> Reset the chip */
1121 		if (status & FTGMAC100_INT_AHB_ERR) {
1122 			if (net_ratelimit())
1123 				netdev_warn(netdev,
1124 					   "AHB bus error ! Resetting chip.\n");
1125 			iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1126 			schedule_work(&priv->reset_task);
1127 			return IRQ_HANDLED;
1128 		}
1129 
1130 		/* We may need to restart the MAC after such errors, delay
1131 		 * this until after we have freed some Rx buffers though
1132 		 */
1133 		priv->need_mac_restart = true;
1134 
1135 		/* Disable those errors until we restart */
1136 		new_mask &= ~status;
1137 	}
1138 
1139 	/* Only enable "bad" interrupts while NAPI is on */
1140 	iowrite32(new_mask, priv->base + FTGMAC100_OFFSET_IER);
1141 
1142 	/* Schedule NAPI bh */
1143 	napi_schedule_irqoff(&priv->napi);
1144 
1145 	return IRQ_HANDLED;
1146 }
1147 
1148 static bool ftgmac100_check_rx(struct ftgmac100 *priv)
1149 {
1150 	struct ftgmac100_rxdes *rxdes = &priv->rxdes[priv->rx_pointer];
1151 
1152 	/* Do we have a packet ? */
1153 	return !!(rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_RXPKT_RDY));
1154 }
1155 
1156 static int ftgmac100_poll(struct napi_struct *napi, int budget)
1157 {
1158 	struct ftgmac100 *priv = container_of(napi, struct ftgmac100, napi);
1159 	int work_done = 0;
1160 	bool more;
1161 
1162 	/* Handle TX completions */
1163 	if (ftgmac100_tx_buf_cleanable(priv))
1164 		ftgmac100_tx_complete(priv);
1165 
1166 	/* Handle RX packets */
1167 	do {
1168 		more = ftgmac100_rx_packet(priv, &work_done);
1169 	} while (more && work_done < budget);
1170 
1171 
1172 	/* The interrupt is telling us to kick the MAC back to life
1173 	 * after an RX overflow
1174 	 */
1175 	if (unlikely(priv->need_mac_restart)) {
1176 		ftgmac100_start_hw(priv);
1177 
1178 		/* Re-enable "bad" interrupts */
1179 		iowrite32(FTGMAC100_INT_BAD,
1180 			  priv->base + FTGMAC100_OFFSET_IER);
1181 	}
1182 
1183 	/* As long as we are waiting for transmit packets to be
1184 	 * completed we keep NAPI going
1185 	 */
1186 	if (ftgmac100_tx_buf_cleanable(priv))
1187 		work_done = budget;
1188 
1189 	if (work_done < budget) {
1190 		/* We are about to re-enable all interrupts. However
1191 		 * the HW has been latching RX/TX packet interrupts while
1192 		 * they were masked. So we clear them first, then we need
1193 		 * to re-check if there's something to process
1194 		 */
1195 		iowrite32(FTGMAC100_INT_RXTX,
1196 			  priv->base + FTGMAC100_OFFSET_ISR);
1197 		if (ftgmac100_check_rx(priv) ||
1198 		    ftgmac100_tx_buf_cleanable(priv))
1199 			return budget;
1200 
1201 		/* deschedule NAPI */
1202 		napi_complete(napi);
1203 
1204 		/* enable all interrupts */
1205 		iowrite32(FTGMAC100_INT_ALL,
1206 			  priv->base + FTGMAC100_OFFSET_IER);
1207 	}
1208 
1209 	return work_done;
1210 }
1211 
1212 static int ftgmac100_init_all(struct ftgmac100 *priv, bool ignore_alloc_err)
1213 {
1214 	int err = 0;
1215 
1216 	/* Re-init descriptors (adjust queue sizes) */
1217 	ftgmac100_init_rings(priv);
1218 
1219 	/* Realloc rx descriptors */
1220 	err = ftgmac100_alloc_rx_buffers(priv);
1221 	if (err && !ignore_alloc_err)
1222 		return err;
1223 
1224 	/* Reinit and restart HW */
1225 	ftgmac100_init_hw(priv);
1226 	ftgmac100_start_hw(priv);
1227 
1228 	/* Re-enable the device */
1229 	napi_enable(&priv->napi);
1230 	netif_start_queue(priv->netdev);
1231 
1232 	/* Enable all interrupts */
1233 	iowrite32(FTGMAC100_INT_ALL, priv->base + FTGMAC100_OFFSET_IER);
1234 
1235 	return err;
1236 }
1237 
1238 static void ftgmac100_reset_task(struct work_struct *work)
1239 {
1240 	struct ftgmac100 *priv = container_of(work, struct ftgmac100,
1241 					      reset_task);
1242 	struct net_device *netdev = priv->netdev;
1243 	int err;
1244 
1245 	netdev_dbg(netdev, "Resetting NIC...\n");
1246 
1247 	/* Lock the world */
1248 	rtnl_lock();
1249 	if (netdev->phydev)
1250 		mutex_lock(&netdev->phydev->lock);
1251 	if (priv->mii_bus)
1252 		mutex_lock(&priv->mii_bus->mdio_lock);
1253 
1254 
1255 	/* Check if the interface is still up */
1256 	if (!netif_running(netdev))
1257 		goto bail;
1258 
1259 	/* Stop the network stack */
1260 	netif_trans_update(netdev);
1261 	napi_disable(&priv->napi);
1262 	netif_tx_disable(netdev);
1263 
1264 	/* Stop and reset the MAC */
1265 	ftgmac100_stop_hw(priv);
1266 	err = ftgmac100_reset_and_config_mac(priv);
1267 	if (err) {
1268 		/* Not much we can do ... it might come back... */
1269 		netdev_err(netdev, "attempting to continue...\n");
1270 	}
1271 
1272 	/* Free all rx and tx buffers */
1273 	ftgmac100_free_buffers(priv);
1274 
1275 	/* Setup everything again and restart chip */
1276 	ftgmac100_init_all(priv, true);
1277 
1278 	netdev_dbg(netdev, "Reset done !\n");
1279  bail:
1280 	if (priv->mii_bus)
1281 		mutex_unlock(&priv->mii_bus->mdio_lock);
1282 	if (netdev->phydev)
1283 		mutex_unlock(&netdev->phydev->lock);
1284 	rtnl_unlock();
1285 }
1286 
1287 static int ftgmac100_open(struct net_device *netdev)
1288 {
1289 	struct ftgmac100 *priv = netdev_priv(netdev);
1290 	int err;
1291 
1292 	/* Allocate ring buffers  */
1293 	err = ftgmac100_alloc_rings(priv);
1294 	if (err) {
1295 		netdev_err(netdev, "Failed to allocate descriptors\n");
1296 		return err;
1297 	}
1298 
1299 	/* When using NC-SI we force the speed to 100Mbit/s full duplex,
1300 	 *
1301 	 * Otherwise we leave it set to 0 (no link), the link
1302 	 * message from the PHY layer will handle setting it up to
1303 	 * something else if needed.
1304 	 */
1305 	if (priv->use_ncsi) {
1306 		priv->cur_duplex = DUPLEX_FULL;
1307 		priv->cur_speed = SPEED_100;
1308 	} else {
1309 		priv->cur_duplex = 0;
1310 		priv->cur_speed = 0;
1311 	}
1312 
1313 	/* Reset the hardware */
1314 	err = ftgmac100_reset_and_config_mac(priv);
1315 	if (err)
1316 		goto err_hw;
1317 
1318 	/* Initialize NAPI */
1319 	netif_napi_add(netdev, &priv->napi, ftgmac100_poll, 64);
1320 
1321 	/* Grab our interrupt */
1322 	err = request_irq(netdev->irq, ftgmac100_interrupt, 0, netdev->name, netdev);
1323 	if (err) {
1324 		netdev_err(netdev, "failed to request irq %d\n", netdev->irq);
1325 		goto err_irq;
1326 	}
1327 
1328 	/* Start things up */
1329 	err = ftgmac100_init_all(priv, false);
1330 	if (err) {
1331 		netdev_err(netdev, "Failed to allocate packet buffers\n");
1332 		goto err_alloc;
1333 	}
1334 
1335 	if (netdev->phydev) {
1336 		/* If we have a PHY, start polling */
1337 		phy_start(netdev->phydev);
1338 	} else if (priv->use_ncsi) {
1339 		/* If using NC-SI, set our carrier on and start the stack */
1340 		netif_carrier_on(netdev);
1341 
1342 		/* Start the NCSI device */
1343 		err = ncsi_start_dev(priv->ndev);
1344 		if (err)
1345 			goto err_ncsi;
1346 	}
1347 
1348 	return 0;
1349 
1350  err_ncsi:
1351 	napi_disable(&priv->napi);
1352 	netif_stop_queue(netdev);
1353  err_alloc:
1354 	ftgmac100_free_buffers(priv);
1355 	free_irq(netdev->irq, netdev);
1356  err_irq:
1357 	netif_napi_del(&priv->napi);
1358  err_hw:
1359 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1360 	ftgmac100_free_rings(priv);
1361 	return err;
1362 }
1363 
1364 static int ftgmac100_stop(struct net_device *netdev)
1365 {
1366 	struct ftgmac100 *priv = netdev_priv(netdev);
1367 
1368 	/* Note about the reset task: We are called with the rtnl lock
1369 	 * held, so we are synchronized against the core of the reset
1370 	 * task. We must not try to synchronously cancel it otherwise
1371 	 * we can deadlock. But since it will test for netif_running()
1372 	 * which has already been cleared by the net core, we don't
1373 	 * anything special to do.
1374 	 */
1375 
1376 	/* disable all interrupts */
1377 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1378 
1379 	netif_stop_queue(netdev);
1380 	napi_disable(&priv->napi);
1381 	netif_napi_del(&priv->napi);
1382 	if (netdev->phydev)
1383 		phy_stop(netdev->phydev);
1384 	else if (priv->use_ncsi)
1385 		ncsi_stop_dev(priv->ndev);
1386 
1387 	ftgmac100_stop_hw(priv);
1388 	free_irq(netdev->irq, netdev);
1389 	ftgmac100_free_buffers(priv);
1390 	ftgmac100_free_rings(priv);
1391 
1392 	return 0;
1393 }
1394 
1395 /* optional */
1396 static int ftgmac100_do_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
1397 {
1398 	if (!netdev->phydev)
1399 		return -ENXIO;
1400 
1401 	return phy_mii_ioctl(netdev->phydev, ifr, cmd);
1402 }
1403 
1404 static void ftgmac100_tx_timeout(struct net_device *netdev)
1405 {
1406 	struct ftgmac100 *priv = netdev_priv(netdev);
1407 
1408 	/* Disable all interrupts */
1409 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1410 
1411 	/* Do the reset outside of interrupt context */
1412 	schedule_work(&priv->reset_task);
1413 }
1414 
1415 static const struct net_device_ops ftgmac100_netdev_ops = {
1416 	.ndo_open		= ftgmac100_open,
1417 	.ndo_stop		= ftgmac100_stop,
1418 	.ndo_start_xmit		= ftgmac100_hard_start_xmit,
1419 	.ndo_set_mac_address	= ftgmac100_set_mac_addr,
1420 	.ndo_validate_addr	= eth_validate_addr,
1421 	.ndo_do_ioctl		= ftgmac100_do_ioctl,
1422 	.ndo_tx_timeout		= ftgmac100_tx_timeout,
1423 };
1424 
1425 static int ftgmac100_setup_mdio(struct net_device *netdev)
1426 {
1427 	struct ftgmac100 *priv = netdev_priv(netdev);
1428 	struct platform_device *pdev = to_platform_device(priv->dev);
1429 	int i, err = 0;
1430 	u32 reg;
1431 
1432 	/* initialize mdio bus */
1433 	priv->mii_bus = mdiobus_alloc();
1434 	if (!priv->mii_bus)
1435 		return -EIO;
1436 
1437 	if (priv->is_aspeed) {
1438 		/* This driver supports the old MDIO interface */
1439 		reg = ioread32(priv->base + FTGMAC100_OFFSET_REVR);
1440 		reg &= ~FTGMAC100_REVR_NEW_MDIO_INTERFACE;
1441 		iowrite32(reg, priv->base + FTGMAC100_OFFSET_REVR);
1442 	};
1443 
1444 	priv->mii_bus->name = "ftgmac100_mdio";
1445 	snprintf(priv->mii_bus->id, MII_BUS_ID_SIZE, "%s-%d",
1446 		 pdev->name, pdev->id);
1447 	priv->mii_bus->priv = priv->netdev;
1448 	priv->mii_bus->read = ftgmac100_mdiobus_read;
1449 	priv->mii_bus->write = ftgmac100_mdiobus_write;
1450 
1451 	for (i = 0; i < PHY_MAX_ADDR; i++)
1452 		priv->mii_bus->irq[i] = PHY_POLL;
1453 
1454 	err = mdiobus_register(priv->mii_bus);
1455 	if (err) {
1456 		dev_err(priv->dev, "Cannot register MDIO bus!\n");
1457 		goto err_register_mdiobus;
1458 	}
1459 
1460 	err = ftgmac100_mii_probe(priv);
1461 	if (err) {
1462 		dev_err(priv->dev, "MII Probe failed!\n");
1463 		goto err_mii_probe;
1464 	}
1465 
1466 	return 0;
1467 
1468 err_mii_probe:
1469 	mdiobus_unregister(priv->mii_bus);
1470 err_register_mdiobus:
1471 	mdiobus_free(priv->mii_bus);
1472 	return err;
1473 }
1474 
1475 static void ftgmac100_destroy_mdio(struct net_device *netdev)
1476 {
1477 	struct ftgmac100 *priv = netdev_priv(netdev);
1478 
1479 	if (!netdev->phydev)
1480 		return;
1481 
1482 	phy_disconnect(netdev->phydev);
1483 	mdiobus_unregister(priv->mii_bus);
1484 	mdiobus_free(priv->mii_bus);
1485 }
1486 
1487 static void ftgmac100_ncsi_handler(struct ncsi_dev *nd)
1488 {
1489 	if (unlikely(nd->state != ncsi_dev_state_functional))
1490 		return;
1491 
1492 	netdev_info(nd->dev, "NCSI interface %s\n",
1493 		    nd->link_up ? "up" : "down");
1494 }
1495 
1496 static int ftgmac100_probe(struct platform_device *pdev)
1497 {
1498 	struct resource *res;
1499 	int irq;
1500 	struct net_device *netdev;
1501 	struct ftgmac100 *priv;
1502 	struct device_node *np;
1503 	int err = 0;
1504 
1505 	if (!pdev)
1506 		return -ENODEV;
1507 
1508 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1509 	if (!res)
1510 		return -ENXIO;
1511 
1512 	irq = platform_get_irq(pdev, 0);
1513 	if (irq < 0)
1514 		return irq;
1515 
1516 	/* setup net_device */
1517 	netdev = alloc_etherdev(sizeof(*priv));
1518 	if (!netdev) {
1519 		err = -ENOMEM;
1520 		goto err_alloc_etherdev;
1521 	}
1522 
1523 	SET_NETDEV_DEV(netdev, &pdev->dev);
1524 
1525 	netdev->ethtool_ops = &ftgmac100_ethtool_ops;
1526 	netdev->netdev_ops = &ftgmac100_netdev_ops;
1527 	netdev->watchdog_timeo = 5 * HZ;
1528 
1529 	platform_set_drvdata(pdev, netdev);
1530 
1531 	/* setup private data */
1532 	priv = netdev_priv(netdev);
1533 	priv->netdev = netdev;
1534 	priv->dev = &pdev->dev;
1535 	INIT_WORK(&priv->reset_task, ftgmac100_reset_task);
1536 
1537 	/* map io memory */
1538 	priv->res = request_mem_region(res->start, resource_size(res),
1539 				       dev_name(&pdev->dev));
1540 	if (!priv->res) {
1541 		dev_err(&pdev->dev, "Could not reserve memory region\n");
1542 		err = -ENOMEM;
1543 		goto err_req_mem;
1544 	}
1545 
1546 	priv->base = ioremap(res->start, resource_size(res));
1547 	if (!priv->base) {
1548 		dev_err(&pdev->dev, "Failed to ioremap ethernet registers\n");
1549 		err = -EIO;
1550 		goto err_ioremap;
1551 	}
1552 
1553 	netdev->irq = irq;
1554 
1555 	/* MAC address from chip or random one */
1556 	ftgmac100_initial_mac(priv);
1557 
1558 	np = pdev->dev.of_node;
1559 	if (np && (of_device_is_compatible(np, "aspeed,ast2400-mac") ||
1560 		   of_device_is_compatible(np, "aspeed,ast2500-mac"))) {
1561 		priv->rxdes0_edorr_mask = BIT(30);
1562 		priv->txdes0_edotr_mask = BIT(30);
1563 		priv->is_aspeed = true;
1564 	} else {
1565 		priv->rxdes0_edorr_mask = BIT(15);
1566 		priv->txdes0_edotr_mask = BIT(15);
1567 	}
1568 
1569 	if (np && of_get_property(np, "use-ncsi", NULL)) {
1570 		if (!IS_ENABLED(CONFIG_NET_NCSI)) {
1571 			dev_err(&pdev->dev, "NCSI stack not enabled\n");
1572 			goto err_ncsi_dev;
1573 		}
1574 
1575 		dev_info(&pdev->dev, "Using NCSI interface\n");
1576 		priv->use_ncsi = true;
1577 		priv->ndev = ncsi_register_dev(netdev, ftgmac100_ncsi_handler);
1578 		if (!priv->ndev)
1579 			goto err_ncsi_dev;
1580 	} else {
1581 		priv->use_ncsi = false;
1582 		err = ftgmac100_setup_mdio(netdev);
1583 		if (err)
1584 			goto err_setup_mdio;
1585 	}
1586 
1587 	/* Default ring sizes */
1588 	priv->rx_q_entries = priv->new_rx_q_entries = DEF_RX_QUEUE_ENTRIES;
1589 	priv->tx_q_entries = priv->new_tx_q_entries = DEF_TX_QUEUE_ENTRIES;
1590 
1591 	/* Base feature set */
1592 	netdev->hw_features = NETIF_F_RXCSUM | NETIF_F_HW_CSUM |
1593 		NETIF_F_GRO | NETIF_F_SG;
1594 
1595 	/* AST2400  doesn't have working HW checksum generation */
1596 	if (np && (of_device_is_compatible(np, "aspeed,ast2400-mac")))
1597 		netdev->hw_features &= ~NETIF_F_HW_CSUM;
1598 	if (np && of_get_property(np, "no-hw-checksum", NULL))
1599 		netdev->hw_features &= ~(NETIF_F_HW_CSUM | NETIF_F_RXCSUM);
1600 	netdev->features |= netdev->hw_features;
1601 
1602 	/* register network device */
1603 	err = register_netdev(netdev);
1604 	if (err) {
1605 		dev_err(&pdev->dev, "Failed to register netdev\n");
1606 		goto err_register_netdev;
1607 	}
1608 
1609 	netdev_info(netdev, "irq %d, mapped at %p\n", netdev->irq, priv->base);
1610 
1611 	return 0;
1612 
1613 err_ncsi_dev:
1614 err_register_netdev:
1615 	ftgmac100_destroy_mdio(netdev);
1616 err_setup_mdio:
1617 	iounmap(priv->base);
1618 err_ioremap:
1619 	release_resource(priv->res);
1620 err_req_mem:
1621 	netif_napi_del(&priv->napi);
1622 	free_netdev(netdev);
1623 err_alloc_etherdev:
1624 	return err;
1625 }
1626 
1627 static int ftgmac100_remove(struct platform_device *pdev)
1628 {
1629 	struct net_device *netdev;
1630 	struct ftgmac100 *priv;
1631 
1632 	netdev = platform_get_drvdata(pdev);
1633 	priv = netdev_priv(netdev);
1634 
1635 	unregister_netdev(netdev);
1636 
1637 	/* There's a small chance the reset task will have been re-queued,
1638 	 * during stop, make sure it's gone before we free the structure.
1639 	 */
1640 	cancel_work_sync(&priv->reset_task);
1641 
1642 	ftgmac100_destroy_mdio(netdev);
1643 
1644 	iounmap(priv->base);
1645 	release_resource(priv->res);
1646 
1647 	netif_napi_del(&priv->napi);
1648 	free_netdev(netdev);
1649 	return 0;
1650 }
1651 
1652 static const struct of_device_id ftgmac100_of_match[] = {
1653 	{ .compatible = "faraday,ftgmac100" },
1654 	{ }
1655 };
1656 MODULE_DEVICE_TABLE(of, ftgmac100_of_match);
1657 
1658 static struct platform_driver ftgmac100_driver = {
1659 	.probe	= ftgmac100_probe,
1660 	.remove	= ftgmac100_remove,
1661 	.driver	= {
1662 		.name		= DRV_NAME,
1663 		.of_match_table	= ftgmac100_of_match,
1664 	},
1665 };
1666 module_platform_driver(ftgmac100_driver);
1667 
1668 MODULE_AUTHOR("Po-Yu Chuang <ratbert@faraday-tech.com>");
1669 MODULE_DESCRIPTION("FTGMAC100 driver");
1670 MODULE_LICENSE("GPL");
1671