xref: /linux/drivers/net/ethernet/xilinx/xilinx_axienet_main.c (revision 9ca12e50a48c100e3bda3e5152d2181f4a6649e2)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Xilinx Axi Ethernet device driver
4  *
5  * Copyright (c) 2008 Nissin Systems Co., Ltd.,  Yoshio Kashiwagi
6  * Copyright (c) 2005-2008 DLA Systems,  David H. Lynch Jr. <dhlii@dlasys.net>
7  * Copyright (c) 2008-2009 Secret Lab Technologies Ltd.
8  * Copyright (c) 2010 - 2011 Michal Simek <monstr@monstr.eu>
9  * Copyright (c) 2010 - 2011 PetaLogix
10  * Copyright (c) 2019 - 2022 Calian Advanced Technologies
11  * Copyright (c) 2010 - 2012 Xilinx, Inc. All rights reserved.
12  *
13  * This is a driver for the Xilinx Axi Ethernet which is used in the Virtex6
14  * and Spartan6.
15  *
16  * TODO:
17  *  - Add Axi Fifo support.
18  *  - Factor out Axi DMA code into separate driver.
19  *  - Test and fix basic multicast filtering.
20  *  - Add support for extended multicast filtering.
21  *  - Test basic VLAN support.
22  *  - Add support for extended VLAN support.
23  */
24 
25 #include <linux/clk.h>
26 #include <linux/delay.h>
27 #include <linux/etherdevice.h>
28 #include <linux/module.h>
29 #include <linux/netdevice.h>
30 #include <linux/of.h>
31 #include <linux/of_mdio.h>
32 #include <linux/of_net.h>
33 #include <linux/of_irq.h>
34 #include <linux/of_address.h>
35 #include <linux/platform_device.h>
36 #include <linux/skbuff.h>
37 #include <linux/math64.h>
38 #include <linux/phy.h>
39 #include <linux/mii.h>
40 #include <linux/ethtool.h>
41 #include <linux/dmaengine.h>
42 #include <linux/dma-mapping.h>
43 #include <linux/dma/xilinx_dma.h>
44 #include <linux/circ_buf.h>
45 #include <net/netdev_queues.h>
46 
47 #include "xilinx_axienet.h"
48 
49 /* Descriptors defines for Tx and Rx DMA */
50 #define TX_BD_NUM_DEFAULT		128
51 #define RX_BD_NUM_DEFAULT		1024
52 #define TX_BD_NUM_MIN			(MAX_SKB_FRAGS + 1)
53 #define TX_BD_NUM_MAX			4096
54 #define RX_BD_NUM_MAX			4096
55 #define DMA_NUM_APP_WORDS		5
56 #define LEN_APP				4
57 #define RX_BUF_NUM_DEFAULT		128
58 
59 /* Must be shorter than length of ethtool_drvinfo.driver field to fit */
60 #define DRIVER_NAME		"xaxienet"
61 #define DRIVER_DESCRIPTION	"Xilinx Axi Ethernet driver"
62 #define DRIVER_VERSION		"1.00a"
63 
64 #define AXIENET_REGS_N		40
65 
66 static void axienet_rx_submit_desc(struct net_device *ndev);
67 
68 /* Match table for of_platform binding */
69 static const struct of_device_id axienet_of_match[] = {
70 	{ .compatible = "xlnx,axi-ethernet-1.00.a", },
71 	{ .compatible = "xlnx,axi-ethernet-1.01.a", },
72 	{ .compatible = "xlnx,axi-ethernet-2.01.a", },
73 	{},
74 };
75 
76 MODULE_DEVICE_TABLE(of, axienet_of_match);
77 
78 /* Option table for setting up Axi Ethernet hardware options */
79 static struct axienet_option axienet_options[] = {
80 	/* Turn on jumbo packet support for both Rx and Tx */
81 	{
82 		.opt = XAE_OPTION_JUMBO,
83 		.reg = XAE_TC_OFFSET,
84 		.m_or = XAE_TC_JUM_MASK,
85 	}, {
86 		.opt = XAE_OPTION_JUMBO,
87 		.reg = XAE_RCW1_OFFSET,
88 		.m_or = XAE_RCW1_JUM_MASK,
89 	}, { /* Turn on VLAN packet support for both Rx and Tx */
90 		.opt = XAE_OPTION_VLAN,
91 		.reg = XAE_TC_OFFSET,
92 		.m_or = XAE_TC_VLAN_MASK,
93 	}, {
94 		.opt = XAE_OPTION_VLAN,
95 		.reg = XAE_RCW1_OFFSET,
96 		.m_or = XAE_RCW1_VLAN_MASK,
97 	}, { /* Turn on FCS stripping on receive packets */
98 		.opt = XAE_OPTION_FCS_STRIP,
99 		.reg = XAE_RCW1_OFFSET,
100 		.m_or = XAE_RCW1_FCS_MASK,
101 	}, { /* Turn on FCS insertion on transmit packets */
102 		.opt = XAE_OPTION_FCS_INSERT,
103 		.reg = XAE_TC_OFFSET,
104 		.m_or = XAE_TC_FCS_MASK,
105 	}, { /* Turn off length/type field checking on receive packets */
106 		.opt = XAE_OPTION_LENTYPE_ERR,
107 		.reg = XAE_RCW1_OFFSET,
108 		.m_or = XAE_RCW1_LT_DIS_MASK,
109 	}, { /* Turn on Rx flow control */
110 		.opt = XAE_OPTION_FLOW_CONTROL,
111 		.reg = XAE_FCC_OFFSET,
112 		.m_or = XAE_FCC_FCRX_MASK,
113 	}, { /* Turn on Tx flow control */
114 		.opt = XAE_OPTION_FLOW_CONTROL,
115 		.reg = XAE_FCC_OFFSET,
116 		.m_or = XAE_FCC_FCTX_MASK,
117 	}, { /* Turn on promiscuous frame filtering */
118 		.opt = XAE_OPTION_PROMISC,
119 		.reg = XAE_FMI_OFFSET,
120 		.m_or = XAE_FMI_PM_MASK,
121 	}, { /* Enable transmitter */
122 		.opt = XAE_OPTION_TXEN,
123 		.reg = XAE_TC_OFFSET,
124 		.m_or = XAE_TC_TX_MASK,
125 	}, { /* Enable receiver */
126 		.opt = XAE_OPTION_RXEN,
127 		.reg = XAE_RCW1_OFFSET,
128 		.m_or = XAE_RCW1_RX_MASK,
129 	},
130 	{}
131 };
132 
133 static struct skbuf_dma_descriptor *axienet_get_rx_desc(struct axienet_local *lp, int i)
134 {
135 	return lp->rx_skb_ring[i & (RX_BUF_NUM_DEFAULT - 1)];
136 }
137 
138 static struct skbuf_dma_descriptor *axienet_get_tx_desc(struct axienet_local *lp, int i)
139 {
140 	return lp->tx_skb_ring[i & (TX_BD_NUM_MAX - 1)];
141 }
142 
143 /**
144  * axienet_dma_in32 - Memory mapped Axi DMA register read
145  * @lp:		Pointer to axienet local structure
146  * @reg:	Address offset from the base address of the Axi DMA core
147  *
148  * Return: The contents of the Axi DMA register
149  *
150  * This function returns the contents of the corresponding Axi DMA register.
151  */
152 static inline u32 axienet_dma_in32(struct axienet_local *lp, off_t reg)
153 {
154 	return ioread32(lp->dma_regs + reg);
155 }
156 
157 static void desc_set_phys_addr(struct axienet_local *lp, dma_addr_t addr,
158 			       struct axidma_bd *desc)
159 {
160 	desc->phys = lower_32_bits(addr);
161 	if (lp->features & XAE_FEATURE_DMA_64BIT)
162 		desc->phys_msb = upper_32_bits(addr);
163 }
164 
165 static dma_addr_t desc_get_phys_addr(struct axienet_local *lp,
166 				     struct axidma_bd *desc)
167 {
168 	dma_addr_t ret = desc->phys;
169 
170 	if (lp->features & XAE_FEATURE_DMA_64BIT)
171 		ret |= ((dma_addr_t)desc->phys_msb << 16) << 16;
172 
173 	return ret;
174 }
175 
176 /**
177  * axienet_dma_bd_release - Release buffer descriptor rings
178  * @ndev:	Pointer to the net_device structure
179  *
180  * This function is used to release the descriptors allocated in
181  * axienet_dma_bd_init. axienet_dma_bd_release is called when Axi Ethernet
182  * driver stop api is called.
183  */
184 static void axienet_dma_bd_release(struct net_device *ndev)
185 {
186 	int i;
187 	struct axienet_local *lp = netdev_priv(ndev);
188 
189 	/* If we end up here, tx_bd_v must have been DMA allocated. */
190 	dma_free_coherent(lp->dev,
191 			  sizeof(*lp->tx_bd_v) * lp->tx_bd_num,
192 			  lp->tx_bd_v,
193 			  lp->tx_bd_p);
194 
195 	if (!lp->rx_bd_v)
196 		return;
197 
198 	for (i = 0; i < lp->rx_bd_num; i++) {
199 		dma_addr_t phys;
200 
201 		/* A NULL skb means this descriptor has not been initialised
202 		 * at all.
203 		 */
204 		if (!lp->rx_bd_v[i].skb)
205 			break;
206 
207 		dev_kfree_skb(lp->rx_bd_v[i].skb);
208 
209 		/* For each descriptor, we programmed cntrl with the (non-zero)
210 		 * descriptor size, after it had been successfully allocated.
211 		 * So a non-zero value in there means we need to unmap it.
212 		 */
213 		if (lp->rx_bd_v[i].cntrl) {
214 			phys = desc_get_phys_addr(lp, &lp->rx_bd_v[i]);
215 			dma_unmap_single(lp->dev, phys,
216 					 lp->max_frm_size, DMA_FROM_DEVICE);
217 		}
218 	}
219 
220 	dma_free_coherent(lp->dev,
221 			  sizeof(*lp->rx_bd_v) * lp->rx_bd_num,
222 			  lp->rx_bd_v,
223 			  lp->rx_bd_p);
224 }
225 
226 /**
227  * axienet_usec_to_timer - Calculate IRQ delay timer value
228  * @lp:		Pointer to the axienet_local structure
229  * @coalesce_usec: Microseconds to convert into timer value
230  */
231 static u32 axienet_usec_to_timer(struct axienet_local *lp, u32 coalesce_usec)
232 {
233 	u32 result;
234 	u64 clk_rate = 125000000; /* arbitrary guess if no clock rate set */
235 
236 	if (lp->axi_clk)
237 		clk_rate = clk_get_rate(lp->axi_clk);
238 
239 	/* 1 Timeout Interval = 125 * (clock period of SG clock) */
240 	result = DIV64_U64_ROUND_CLOSEST((u64)coalesce_usec * clk_rate,
241 					 (u64)125000000);
242 	if (result > 255)
243 		result = 255;
244 
245 	return result;
246 }
247 
248 /**
249  * axienet_dma_start - Set up DMA registers and start DMA operation
250  * @lp:		Pointer to the axienet_local structure
251  */
252 static void axienet_dma_start(struct axienet_local *lp)
253 {
254 	/* Start updating the Rx channel control register */
255 	lp->rx_dma_cr = (lp->coalesce_count_rx << XAXIDMA_COALESCE_SHIFT) |
256 			XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_ERROR_MASK;
257 	/* Only set interrupt delay timer if not generating an interrupt on
258 	 * the first RX packet. Otherwise leave at 0 to disable delay interrupt.
259 	 */
260 	if (lp->coalesce_count_rx > 1)
261 		lp->rx_dma_cr |= (axienet_usec_to_timer(lp, lp->coalesce_usec_rx)
262 					<< XAXIDMA_DELAY_SHIFT) |
263 				 XAXIDMA_IRQ_DELAY_MASK;
264 	axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, lp->rx_dma_cr);
265 
266 	/* Start updating the Tx channel control register */
267 	lp->tx_dma_cr = (lp->coalesce_count_tx << XAXIDMA_COALESCE_SHIFT) |
268 			XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_ERROR_MASK;
269 	/* Only set interrupt delay timer if not generating an interrupt on
270 	 * the first TX packet. Otherwise leave at 0 to disable delay interrupt.
271 	 */
272 	if (lp->coalesce_count_tx > 1)
273 		lp->tx_dma_cr |= (axienet_usec_to_timer(lp, lp->coalesce_usec_tx)
274 					<< XAXIDMA_DELAY_SHIFT) |
275 				 XAXIDMA_IRQ_DELAY_MASK;
276 	axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, lp->tx_dma_cr);
277 
278 	/* Populate the tail pointer and bring the Rx Axi DMA engine out of
279 	 * halted state. This will make the Rx side ready for reception.
280 	 */
281 	axienet_dma_out_addr(lp, XAXIDMA_RX_CDESC_OFFSET, lp->rx_bd_p);
282 	lp->rx_dma_cr |= XAXIDMA_CR_RUNSTOP_MASK;
283 	axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, lp->rx_dma_cr);
284 	axienet_dma_out_addr(lp, XAXIDMA_RX_TDESC_OFFSET, lp->rx_bd_p +
285 			     (sizeof(*lp->rx_bd_v) * (lp->rx_bd_num - 1)));
286 
287 	/* Write to the RS (Run-stop) bit in the Tx channel control register.
288 	 * Tx channel is now ready to run. But only after we write to the
289 	 * tail pointer register that the Tx channel will start transmitting.
290 	 */
291 	axienet_dma_out_addr(lp, XAXIDMA_TX_CDESC_OFFSET, lp->tx_bd_p);
292 	lp->tx_dma_cr |= XAXIDMA_CR_RUNSTOP_MASK;
293 	axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, lp->tx_dma_cr);
294 }
295 
296 /**
297  * axienet_dma_bd_init - Setup buffer descriptor rings for Axi DMA
298  * @ndev:	Pointer to the net_device structure
299  *
300  * Return: 0, on success -ENOMEM, on failure
301  *
302  * This function is called to initialize the Rx and Tx DMA descriptor
303  * rings. This initializes the descriptors with required default values
304  * and is called when Axi Ethernet driver reset is called.
305  */
306 static int axienet_dma_bd_init(struct net_device *ndev)
307 {
308 	int i;
309 	struct sk_buff *skb;
310 	struct axienet_local *lp = netdev_priv(ndev);
311 
312 	/* Reset the indexes which are used for accessing the BDs */
313 	lp->tx_bd_ci = 0;
314 	lp->tx_bd_tail = 0;
315 	lp->rx_bd_ci = 0;
316 
317 	/* Allocate the Tx and Rx buffer descriptors. */
318 	lp->tx_bd_v = dma_alloc_coherent(lp->dev,
319 					 sizeof(*lp->tx_bd_v) * lp->tx_bd_num,
320 					 &lp->tx_bd_p, GFP_KERNEL);
321 	if (!lp->tx_bd_v)
322 		return -ENOMEM;
323 
324 	lp->rx_bd_v = dma_alloc_coherent(lp->dev,
325 					 sizeof(*lp->rx_bd_v) * lp->rx_bd_num,
326 					 &lp->rx_bd_p, GFP_KERNEL);
327 	if (!lp->rx_bd_v)
328 		goto out;
329 
330 	for (i = 0; i < lp->tx_bd_num; i++) {
331 		dma_addr_t addr = lp->tx_bd_p +
332 				  sizeof(*lp->tx_bd_v) *
333 				  ((i + 1) % lp->tx_bd_num);
334 
335 		lp->tx_bd_v[i].next = lower_32_bits(addr);
336 		if (lp->features & XAE_FEATURE_DMA_64BIT)
337 			lp->tx_bd_v[i].next_msb = upper_32_bits(addr);
338 	}
339 
340 	for (i = 0; i < lp->rx_bd_num; i++) {
341 		dma_addr_t addr;
342 
343 		addr = lp->rx_bd_p + sizeof(*lp->rx_bd_v) *
344 			((i + 1) % lp->rx_bd_num);
345 		lp->rx_bd_v[i].next = lower_32_bits(addr);
346 		if (lp->features & XAE_FEATURE_DMA_64BIT)
347 			lp->rx_bd_v[i].next_msb = upper_32_bits(addr);
348 
349 		skb = netdev_alloc_skb_ip_align(ndev, lp->max_frm_size);
350 		if (!skb)
351 			goto out;
352 
353 		lp->rx_bd_v[i].skb = skb;
354 		addr = dma_map_single(lp->dev, skb->data,
355 				      lp->max_frm_size, DMA_FROM_DEVICE);
356 		if (dma_mapping_error(lp->dev, addr)) {
357 			netdev_err(ndev, "DMA mapping error\n");
358 			goto out;
359 		}
360 		desc_set_phys_addr(lp, addr, &lp->rx_bd_v[i]);
361 
362 		lp->rx_bd_v[i].cntrl = lp->max_frm_size;
363 	}
364 
365 	axienet_dma_start(lp);
366 
367 	return 0;
368 out:
369 	axienet_dma_bd_release(ndev);
370 	return -ENOMEM;
371 }
372 
373 /**
374  * axienet_set_mac_address - Write the MAC address
375  * @ndev:	Pointer to the net_device structure
376  * @address:	6 byte Address to be written as MAC address
377  *
378  * This function is called to initialize the MAC address of the Axi Ethernet
379  * core. It writes to the UAW0 and UAW1 registers of the core.
380  */
381 static void axienet_set_mac_address(struct net_device *ndev,
382 				    const void *address)
383 {
384 	struct axienet_local *lp = netdev_priv(ndev);
385 
386 	if (address)
387 		eth_hw_addr_set(ndev, address);
388 	if (!is_valid_ether_addr(ndev->dev_addr))
389 		eth_hw_addr_random(ndev);
390 
391 	/* Set up unicast MAC address filter set its mac address */
392 	axienet_iow(lp, XAE_UAW0_OFFSET,
393 		    (ndev->dev_addr[0]) |
394 		    (ndev->dev_addr[1] << 8) |
395 		    (ndev->dev_addr[2] << 16) |
396 		    (ndev->dev_addr[3] << 24));
397 	axienet_iow(lp, XAE_UAW1_OFFSET,
398 		    (((axienet_ior(lp, XAE_UAW1_OFFSET)) &
399 		      ~XAE_UAW1_UNICASTADDR_MASK) |
400 		     (ndev->dev_addr[4] |
401 		     (ndev->dev_addr[5] << 8))));
402 }
403 
404 /**
405  * netdev_set_mac_address - Write the MAC address (from outside the driver)
406  * @ndev:	Pointer to the net_device structure
407  * @p:		6 byte Address to be written as MAC address
408  *
409  * Return: 0 for all conditions. Presently, there is no failure case.
410  *
411  * This function is called to initialize the MAC address of the Axi Ethernet
412  * core. It calls the core specific axienet_set_mac_address. This is the
413  * function that goes into net_device_ops structure entry ndo_set_mac_address.
414  */
415 static int netdev_set_mac_address(struct net_device *ndev, void *p)
416 {
417 	struct sockaddr *addr = p;
418 	axienet_set_mac_address(ndev, addr->sa_data);
419 	return 0;
420 }
421 
422 /**
423  * axienet_set_multicast_list - Prepare the multicast table
424  * @ndev:	Pointer to the net_device structure
425  *
426  * This function is called to initialize the multicast table during
427  * initialization. The Axi Ethernet basic multicast support has a four-entry
428  * multicast table which is initialized here. Additionally this function
429  * goes into the net_device_ops structure entry ndo_set_multicast_list. This
430  * means whenever the multicast table entries need to be updated this
431  * function gets called.
432  */
433 static void axienet_set_multicast_list(struct net_device *ndev)
434 {
435 	int i;
436 	u32 reg, af0reg, af1reg;
437 	struct axienet_local *lp = netdev_priv(ndev);
438 
439 	if (ndev->flags & (IFF_ALLMULTI | IFF_PROMISC) ||
440 	    netdev_mc_count(ndev) > XAE_MULTICAST_CAM_TABLE_NUM) {
441 		/* We must make the kernel realize we had to move into
442 		 * promiscuous mode. If it was a promiscuous mode request
443 		 * the flag is already set. If not we set it.
444 		 */
445 		ndev->flags |= IFF_PROMISC;
446 		reg = axienet_ior(lp, XAE_FMI_OFFSET);
447 		reg |= XAE_FMI_PM_MASK;
448 		axienet_iow(lp, XAE_FMI_OFFSET, reg);
449 		dev_info(&ndev->dev, "Promiscuous mode enabled.\n");
450 	} else if (!netdev_mc_empty(ndev)) {
451 		struct netdev_hw_addr *ha;
452 
453 		i = 0;
454 		netdev_for_each_mc_addr(ha, ndev) {
455 			if (i >= XAE_MULTICAST_CAM_TABLE_NUM)
456 				break;
457 
458 			af0reg = (ha->addr[0]);
459 			af0reg |= (ha->addr[1] << 8);
460 			af0reg |= (ha->addr[2] << 16);
461 			af0reg |= (ha->addr[3] << 24);
462 
463 			af1reg = (ha->addr[4]);
464 			af1reg |= (ha->addr[5] << 8);
465 
466 			reg = axienet_ior(lp, XAE_FMI_OFFSET) & 0xFFFFFF00;
467 			reg |= i;
468 
469 			axienet_iow(lp, XAE_FMI_OFFSET, reg);
470 			axienet_iow(lp, XAE_AF0_OFFSET, af0reg);
471 			axienet_iow(lp, XAE_AF1_OFFSET, af1reg);
472 			i++;
473 		}
474 	} else {
475 		reg = axienet_ior(lp, XAE_FMI_OFFSET);
476 		reg &= ~XAE_FMI_PM_MASK;
477 
478 		axienet_iow(lp, XAE_FMI_OFFSET, reg);
479 
480 		for (i = 0; i < XAE_MULTICAST_CAM_TABLE_NUM; i++) {
481 			reg = axienet_ior(lp, XAE_FMI_OFFSET) & 0xFFFFFF00;
482 			reg |= i;
483 
484 			axienet_iow(lp, XAE_FMI_OFFSET, reg);
485 			axienet_iow(lp, XAE_AF0_OFFSET, 0);
486 			axienet_iow(lp, XAE_AF1_OFFSET, 0);
487 		}
488 
489 		dev_info(&ndev->dev, "Promiscuous mode disabled.\n");
490 	}
491 }
492 
493 /**
494  * axienet_setoptions - Set an Axi Ethernet option
495  * @ndev:	Pointer to the net_device structure
496  * @options:	Option to be enabled/disabled
497  *
498  * The Axi Ethernet core has multiple features which can be selectively turned
499  * on or off. The typical options could be jumbo frame option, basic VLAN
500  * option, promiscuous mode option etc. This function is used to set or clear
501  * these options in the Axi Ethernet hardware. This is done through
502  * axienet_option structure .
503  */
504 static void axienet_setoptions(struct net_device *ndev, u32 options)
505 {
506 	int reg;
507 	struct axienet_local *lp = netdev_priv(ndev);
508 	struct axienet_option *tp = &axienet_options[0];
509 
510 	while (tp->opt) {
511 		reg = ((axienet_ior(lp, tp->reg)) & ~(tp->m_or));
512 		if (options & tp->opt)
513 			reg |= tp->m_or;
514 		axienet_iow(lp, tp->reg, reg);
515 		tp++;
516 	}
517 
518 	lp->options |= options;
519 }
520 
521 static int __axienet_device_reset(struct axienet_local *lp)
522 {
523 	u32 value;
524 	int ret;
525 
526 	/* Reset Axi DMA. This would reset Axi Ethernet core as well. The reset
527 	 * process of Axi DMA takes a while to complete as all pending
528 	 * commands/transfers will be flushed or completed during this
529 	 * reset process.
530 	 * Note that even though both TX and RX have their own reset register,
531 	 * they both reset the entire DMA core, so only one needs to be used.
532 	 */
533 	axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, XAXIDMA_CR_RESET_MASK);
534 	ret = read_poll_timeout(axienet_dma_in32, value,
535 				!(value & XAXIDMA_CR_RESET_MASK),
536 				DELAY_OF_ONE_MILLISEC, 50000, false, lp,
537 				XAXIDMA_TX_CR_OFFSET);
538 	if (ret) {
539 		dev_err(lp->dev, "%s: DMA reset timeout!\n", __func__);
540 		return ret;
541 	}
542 
543 	/* Wait for PhyRstCmplt bit to be set, indicating the PHY reset has finished */
544 	ret = read_poll_timeout(axienet_ior, value,
545 				value & XAE_INT_PHYRSTCMPLT_MASK,
546 				DELAY_OF_ONE_MILLISEC, 50000, false, lp,
547 				XAE_IS_OFFSET);
548 	if (ret) {
549 		dev_err(lp->dev, "%s: timeout waiting for PhyRstCmplt\n", __func__);
550 		return ret;
551 	}
552 
553 	return 0;
554 }
555 
556 /**
557  * axienet_dma_stop - Stop DMA operation
558  * @lp:		Pointer to the axienet_local structure
559  */
560 static void axienet_dma_stop(struct axienet_local *lp)
561 {
562 	int count;
563 	u32 cr, sr;
564 
565 	cr = axienet_dma_in32(lp, XAXIDMA_RX_CR_OFFSET);
566 	cr &= ~(XAXIDMA_CR_RUNSTOP_MASK | XAXIDMA_IRQ_ALL_MASK);
567 	axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr);
568 	synchronize_irq(lp->rx_irq);
569 
570 	cr = axienet_dma_in32(lp, XAXIDMA_TX_CR_OFFSET);
571 	cr &= ~(XAXIDMA_CR_RUNSTOP_MASK | XAXIDMA_IRQ_ALL_MASK);
572 	axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, cr);
573 	synchronize_irq(lp->tx_irq);
574 
575 	/* Give DMAs a chance to halt gracefully */
576 	sr = axienet_dma_in32(lp, XAXIDMA_RX_SR_OFFSET);
577 	for (count = 0; !(sr & XAXIDMA_SR_HALT_MASK) && count < 5; ++count) {
578 		msleep(20);
579 		sr = axienet_dma_in32(lp, XAXIDMA_RX_SR_OFFSET);
580 	}
581 
582 	sr = axienet_dma_in32(lp, XAXIDMA_TX_SR_OFFSET);
583 	for (count = 0; !(sr & XAXIDMA_SR_HALT_MASK) && count < 5; ++count) {
584 		msleep(20);
585 		sr = axienet_dma_in32(lp, XAXIDMA_TX_SR_OFFSET);
586 	}
587 
588 	/* Do a reset to ensure DMA is really stopped */
589 	axienet_lock_mii(lp);
590 	__axienet_device_reset(lp);
591 	axienet_unlock_mii(lp);
592 }
593 
594 /**
595  * axienet_device_reset - Reset and initialize the Axi Ethernet hardware.
596  * @ndev:	Pointer to the net_device structure
597  *
598  * This function is called to reset and initialize the Axi Ethernet core. This
599  * is typically called during initialization. It does a reset of the Axi DMA
600  * Rx/Tx channels and initializes the Axi DMA BDs. Since Axi DMA reset lines
601  * are connected to Axi Ethernet reset lines, this in turn resets the Axi
602  * Ethernet core. No separate hardware reset is done for the Axi Ethernet
603  * core.
604  * Returns 0 on success or a negative error number otherwise.
605  */
606 static int axienet_device_reset(struct net_device *ndev)
607 {
608 	u32 axienet_status;
609 	struct axienet_local *lp = netdev_priv(ndev);
610 	int ret;
611 
612 	lp->max_frm_size = XAE_MAX_VLAN_FRAME_SIZE;
613 	lp->options |= XAE_OPTION_VLAN;
614 	lp->options &= (~XAE_OPTION_JUMBO);
615 
616 	if ((ndev->mtu > XAE_MTU) &&
617 	    (ndev->mtu <= XAE_JUMBO_MTU)) {
618 		lp->max_frm_size = ndev->mtu + VLAN_ETH_HLEN +
619 					XAE_TRL_SIZE;
620 
621 		if (lp->max_frm_size <= lp->rxmem)
622 			lp->options |= XAE_OPTION_JUMBO;
623 	}
624 
625 	if (!lp->use_dmaengine) {
626 		ret = __axienet_device_reset(lp);
627 		if (ret)
628 			return ret;
629 
630 		ret = axienet_dma_bd_init(ndev);
631 		if (ret) {
632 			netdev_err(ndev, "%s: descriptor allocation failed\n",
633 				   __func__);
634 			return ret;
635 		}
636 	}
637 
638 	axienet_status = axienet_ior(lp, XAE_RCW1_OFFSET);
639 	axienet_status &= ~XAE_RCW1_RX_MASK;
640 	axienet_iow(lp, XAE_RCW1_OFFSET, axienet_status);
641 
642 	axienet_status = axienet_ior(lp, XAE_IP_OFFSET);
643 	if (axienet_status & XAE_INT_RXRJECT_MASK)
644 		axienet_iow(lp, XAE_IS_OFFSET, XAE_INT_RXRJECT_MASK);
645 	axienet_iow(lp, XAE_IE_OFFSET, lp->eth_irq > 0 ?
646 		    XAE_INT_RECV_ERROR_MASK : 0);
647 
648 	axienet_iow(lp, XAE_FCC_OFFSET, XAE_FCC_FCRX_MASK);
649 
650 	/* Sync default options with HW but leave receiver and
651 	 * transmitter disabled.
652 	 */
653 	axienet_setoptions(ndev, lp->options &
654 			   ~(XAE_OPTION_TXEN | XAE_OPTION_RXEN));
655 	axienet_set_mac_address(ndev, NULL);
656 	axienet_set_multicast_list(ndev);
657 	axienet_setoptions(ndev, lp->options);
658 
659 	netif_trans_update(ndev);
660 
661 	return 0;
662 }
663 
664 /**
665  * axienet_free_tx_chain - Clean up a series of linked TX descriptors.
666  * @lp:		Pointer to the axienet_local structure
667  * @first_bd:	Index of first descriptor to clean up
668  * @nr_bds:	Max number of descriptors to clean up
669  * @force:	Whether to clean descriptors even if not complete
670  * @sizep:	Pointer to a u32 filled with the total sum of all bytes
671  *		in all cleaned-up descriptors. Ignored if NULL.
672  * @budget:	NAPI budget (use 0 when not called from NAPI poll)
673  *
674  * Would either be called after a successful transmit operation, or after
675  * there was an error when setting up the chain.
676  * Returns the number of descriptors handled.
677  */
678 static int axienet_free_tx_chain(struct axienet_local *lp, u32 first_bd,
679 				 int nr_bds, bool force, u32 *sizep, int budget)
680 {
681 	struct axidma_bd *cur_p;
682 	unsigned int status;
683 	dma_addr_t phys;
684 	int i;
685 
686 	for (i = 0; i < nr_bds; i++) {
687 		cur_p = &lp->tx_bd_v[(first_bd + i) % lp->tx_bd_num];
688 		status = cur_p->status;
689 
690 		/* If force is not specified, clean up only descriptors
691 		 * that have been completed by the MAC.
692 		 */
693 		if (!force && !(status & XAXIDMA_BD_STS_COMPLETE_MASK))
694 			break;
695 
696 		/* Ensure we see complete descriptor update */
697 		dma_rmb();
698 		phys = desc_get_phys_addr(lp, cur_p);
699 		dma_unmap_single(lp->dev, phys,
700 				 (cur_p->cntrl & XAXIDMA_BD_CTRL_LENGTH_MASK),
701 				 DMA_TO_DEVICE);
702 
703 		if (cur_p->skb && (status & XAXIDMA_BD_STS_COMPLETE_MASK))
704 			napi_consume_skb(cur_p->skb, budget);
705 
706 		cur_p->app0 = 0;
707 		cur_p->app1 = 0;
708 		cur_p->app2 = 0;
709 		cur_p->app4 = 0;
710 		cur_p->skb = NULL;
711 		/* ensure our transmit path and device don't prematurely see status cleared */
712 		wmb();
713 		cur_p->cntrl = 0;
714 		cur_p->status = 0;
715 
716 		if (sizep)
717 			*sizep += status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK;
718 	}
719 
720 	return i;
721 }
722 
723 /**
724  * axienet_check_tx_bd_space - Checks if a BD/group of BDs are currently busy
725  * @lp:		Pointer to the axienet_local structure
726  * @num_frag:	The number of BDs to check for
727  *
728  * Return: 0, on success
729  *	    NETDEV_TX_BUSY, if any of the descriptors are not free
730  *
731  * This function is invoked before BDs are allocated and transmission starts.
732  * This function returns 0 if a BD or group of BDs can be allocated for
733  * transmission. If the BD or any of the BDs are not free the function
734  * returns a busy status.
735  */
736 static inline int axienet_check_tx_bd_space(struct axienet_local *lp,
737 					    int num_frag)
738 {
739 	struct axidma_bd *cur_p;
740 
741 	/* Ensure we see all descriptor updates from device or TX polling */
742 	rmb();
743 	cur_p = &lp->tx_bd_v[(READ_ONCE(lp->tx_bd_tail) + num_frag) %
744 			     lp->tx_bd_num];
745 	if (cur_p->cntrl)
746 		return NETDEV_TX_BUSY;
747 	return 0;
748 }
749 
750 /**
751  * axienet_dma_tx_cb - DMA engine callback for TX channel.
752  * @data:       Pointer to the axienet_local structure.
753  * @result:     error reporting through dmaengine_result.
754  * This function is called by dmaengine driver for TX channel to notify
755  * that the transmit is done.
756  */
757 static void axienet_dma_tx_cb(void *data, const struct dmaengine_result *result)
758 {
759 	struct skbuf_dma_descriptor *skbuf_dma;
760 	struct axienet_local *lp = data;
761 	struct netdev_queue *txq;
762 	int len;
763 
764 	skbuf_dma = axienet_get_tx_desc(lp, lp->tx_ring_tail++);
765 	len = skbuf_dma->skb->len;
766 	txq = skb_get_tx_queue(lp->ndev, skbuf_dma->skb);
767 	u64_stats_update_begin(&lp->tx_stat_sync);
768 	u64_stats_add(&lp->tx_bytes, len);
769 	u64_stats_add(&lp->tx_packets, 1);
770 	u64_stats_update_end(&lp->tx_stat_sync);
771 	dma_unmap_sg(lp->dev, skbuf_dma->sgl, skbuf_dma->sg_len, DMA_TO_DEVICE);
772 	dev_consume_skb_any(skbuf_dma->skb);
773 	netif_txq_completed_wake(txq, 1, len,
774 				 CIRC_SPACE(lp->tx_ring_head, lp->tx_ring_tail, TX_BD_NUM_MAX),
775 				 2 * MAX_SKB_FRAGS);
776 }
777 
778 /**
779  * axienet_start_xmit_dmaengine - Starts the transmission.
780  * @skb:        sk_buff pointer that contains data to be Txed.
781  * @ndev:       Pointer to net_device structure.
782  *
783  * Return: NETDEV_TX_OK on success or any non space errors.
784  *         NETDEV_TX_BUSY when free element in TX skb ring buffer
785  *         is not available.
786  *
787  * This function is invoked to initiate transmission. The
788  * function sets the skbs, register dma callback API and submit
789  * the dma transaction.
790  * Additionally if checksum offloading is supported,
791  * it populates AXI Stream Control fields with appropriate values.
792  */
793 static netdev_tx_t
794 axienet_start_xmit_dmaengine(struct sk_buff *skb, struct net_device *ndev)
795 {
796 	struct dma_async_tx_descriptor *dma_tx_desc = NULL;
797 	struct axienet_local *lp = netdev_priv(ndev);
798 	u32 app_metadata[DMA_NUM_APP_WORDS] = {0};
799 	struct skbuf_dma_descriptor *skbuf_dma;
800 	struct dma_device *dma_dev;
801 	struct netdev_queue *txq;
802 	u32 csum_start_off;
803 	u32 csum_index_off;
804 	int sg_len;
805 	int ret;
806 
807 	dma_dev = lp->tx_chan->device;
808 	sg_len = skb_shinfo(skb)->nr_frags + 1;
809 	if (CIRC_SPACE(lp->tx_ring_head, lp->tx_ring_tail, TX_BD_NUM_MAX) <= sg_len) {
810 		netif_stop_queue(ndev);
811 		if (net_ratelimit())
812 			netdev_warn(ndev, "TX ring unexpectedly full\n");
813 		return NETDEV_TX_BUSY;
814 	}
815 
816 	skbuf_dma = axienet_get_tx_desc(lp, lp->tx_ring_head);
817 	if (!skbuf_dma)
818 		goto xmit_error_drop_skb;
819 
820 	lp->tx_ring_head++;
821 	sg_init_table(skbuf_dma->sgl, sg_len);
822 	ret = skb_to_sgvec(skb, skbuf_dma->sgl, 0, skb->len);
823 	if (ret < 0)
824 		goto xmit_error_drop_skb;
825 
826 	ret = dma_map_sg(lp->dev, skbuf_dma->sgl, sg_len, DMA_TO_DEVICE);
827 	if (!ret)
828 		goto xmit_error_drop_skb;
829 
830 	/* Fill up app fields for checksum */
831 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
832 		if (lp->features & XAE_FEATURE_FULL_TX_CSUM) {
833 			/* Tx Full Checksum Offload Enabled */
834 			app_metadata[0] |= 2;
835 		} else if (lp->features & XAE_FEATURE_PARTIAL_TX_CSUM) {
836 			csum_start_off = skb_transport_offset(skb);
837 			csum_index_off = csum_start_off + skb->csum_offset;
838 			/* Tx Partial Checksum Offload Enabled */
839 			app_metadata[0] |= 1;
840 			app_metadata[1] = (csum_start_off << 16) | csum_index_off;
841 		}
842 	} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
843 		app_metadata[0] |= 2; /* Tx Full Checksum Offload Enabled */
844 	}
845 
846 	dma_tx_desc = dma_dev->device_prep_slave_sg(lp->tx_chan, skbuf_dma->sgl,
847 			sg_len, DMA_MEM_TO_DEV,
848 			DMA_PREP_INTERRUPT, (void *)app_metadata);
849 	if (!dma_tx_desc)
850 		goto xmit_error_unmap_sg;
851 
852 	skbuf_dma->skb = skb;
853 	skbuf_dma->sg_len = sg_len;
854 	dma_tx_desc->callback_param = lp;
855 	dma_tx_desc->callback_result = axienet_dma_tx_cb;
856 	dmaengine_submit(dma_tx_desc);
857 	dma_async_issue_pending(lp->tx_chan);
858 	txq = skb_get_tx_queue(lp->ndev, skb);
859 	netdev_tx_sent_queue(txq, skb->len);
860 	netif_txq_maybe_stop(txq, CIRC_SPACE(lp->tx_ring_head, lp->tx_ring_tail, TX_BD_NUM_MAX),
861 			     MAX_SKB_FRAGS + 1, 2 * MAX_SKB_FRAGS);
862 
863 	return NETDEV_TX_OK;
864 
865 xmit_error_unmap_sg:
866 	dma_unmap_sg(lp->dev, skbuf_dma->sgl, sg_len, DMA_TO_DEVICE);
867 xmit_error_drop_skb:
868 	dev_kfree_skb_any(skb);
869 	return NETDEV_TX_OK;
870 }
871 
872 /**
873  * axienet_tx_poll - Invoked once a transmit is completed by the
874  * Axi DMA Tx channel.
875  * @napi:	Pointer to NAPI structure.
876  * @budget:	Max number of TX packets to process.
877  *
878  * Return: Number of TX packets processed.
879  *
880  * This function is invoked from the NAPI processing to notify the completion
881  * of transmit operation. It clears fields in the corresponding Tx BDs and
882  * unmaps the corresponding buffer so that CPU can regain ownership of the
883  * buffer. It finally invokes "netif_wake_queue" to restart transmission if
884  * required.
885  */
886 static int axienet_tx_poll(struct napi_struct *napi, int budget)
887 {
888 	struct axienet_local *lp = container_of(napi, struct axienet_local, napi_tx);
889 	struct net_device *ndev = lp->ndev;
890 	u32 size = 0;
891 	int packets;
892 
893 	packets = axienet_free_tx_chain(lp, lp->tx_bd_ci, budget, false, &size, budget);
894 
895 	if (packets) {
896 		lp->tx_bd_ci += packets;
897 		if (lp->tx_bd_ci >= lp->tx_bd_num)
898 			lp->tx_bd_ci %= lp->tx_bd_num;
899 
900 		u64_stats_update_begin(&lp->tx_stat_sync);
901 		u64_stats_add(&lp->tx_packets, packets);
902 		u64_stats_add(&lp->tx_bytes, size);
903 		u64_stats_update_end(&lp->tx_stat_sync);
904 
905 		/* Matches barrier in axienet_start_xmit */
906 		smp_mb();
907 
908 		if (!axienet_check_tx_bd_space(lp, MAX_SKB_FRAGS + 1))
909 			netif_wake_queue(ndev);
910 	}
911 
912 	if (packets < budget && napi_complete_done(napi, packets)) {
913 		/* Re-enable TX completion interrupts. This should
914 		 * cause an immediate interrupt if any TX packets are
915 		 * already pending.
916 		 */
917 		axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, lp->tx_dma_cr);
918 	}
919 	return packets;
920 }
921 
922 /**
923  * axienet_start_xmit - Starts the transmission.
924  * @skb:	sk_buff pointer that contains data to be Txed.
925  * @ndev:	Pointer to net_device structure.
926  *
927  * Return: NETDEV_TX_OK, on success
928  *	    NETDEV_TX_BUSY, if any of the descriptors are not free
929  *
930  * This function is invoked from upper layers to initiate transmission. The
931  * function uses the next available free BDs and populates their fields to
932  * start the transmission. Additionally if checksum offloading is supported,
933  * it populates AXI Stream Control fields with appropriate values.
934  */
935 static netdev_tx_t
936 axienet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
937 {
938 	u32 ii;
939 	u32 num_frag;
940 	u32 csum_start_off;
941 	u32 csum_index_off;
942 	skb_frag_t *frag;
943 	dma_addr_t tail_p, phys;
944 	u32 orig_tail_ptr, new_tail_ptr;
945 	struct axienet_local *lp = netdev_priv(ndev);
946 	struct axidma_bd *cur_p;
947 
948 	orig_tail_ptr = lp->tx_bd_tail;
949 	new_tail_ptr = orig_tail_ptr;
950 
951 	num_frag = skb_shinfo(skb)->nr_frags;
952 	cur_p = &lp->tx_bd_v[orig_tail_ptr];
953 
954 	if (axienet_check_tx_bd_space(lp, num_frag + 1)) {
955 		/* Should not happen as last start_xmit call should have
956 		 * checked for sufficient space and queue should only be
957 		 * woken when sufficient space is available.
958 		 */
959 		netif_stop_queue(ndev);
960 		if (net_ratelimit())
961 			netdev_warn(ndev, "TX ring unexpectedly full\n");
962 		return NETDEV_TX_BUSY;
963 	}
964 
965 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
966 		if (lp->features & XAE_FEATURE_FULL_TX_CSUM) {
967 			/* Tx Full Checksum Offload Enabled */
968 			cur_p->app0 |= 2;
969 		} else if (lp->features & XAE_FEATURE_PARTIAL_TX_CSUM) {
970 			csum_start_off = skb_transport_offset(skb);
971 			csum_index_off = csum_start_off + skb->csum_offset;
972 			/* Tx Partial Checksum Offload Enabled */
973 			cur_p->app0 |= 1;
974 			cur_p->app1 = (csum_start_off << 16) | csum_index_off;
975 		}
976 	} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
977 		cur_p->app0 |= 2; /* Tx Full Checksum Offload Enabled */
978 	}
979 
980 	phys = dma_map_single(lp->dev, skb->data,
981 			      skb_headlen(skb), DMA_TO_DEVICE);
982 	if (unlikely(dma_mapping_error(lp->dev, phys))) {
983 		if (net_ratelimit())
984 			netdev_err(ndev, "TX DMA mapping error\n");
985 		ndev->stats.tx_dropped++;
986 		return NETDEV_TX_OK;
987 	}
988 	desc_set_phys_addr(lp, phys, cur_p);
989 	cur_p->cntrl = skb_headlen(skb) | XAXIDMA_BD_CTRL_TXSOF_MASK;
990 
991 	for (ii = 0; ii < num_frag; ii++) {
992 		if (++new_tail_ptr >= lp->tx_bd_num)
993 			new_tail_ptr = 0;
994 		cur_p = &lp->tx_bd_v[new_tail_ptr];
995 		frag = &skb_shinfo(skb)->frags[ii];
996 		phys = dma_map_single(lp->dev,
997 				      skb_frag_address(frag),
998 				      skb_frag_size(frag),
999 				      DMA_TO_DEVICE);
1000 		if (unlikely(dma_mapping_error(lp->dev, phys))) {
1001 			if (net_ratelimit())
1002 				netdev_err(ndev, "TX DMA mapping error\n");
1003 			ndev->stats.tx_dropped++;
1004 			axienet_free_tx_chain(lp, orig_tail_ptr, ii + 1,
1005 					      true, NULL, 0);
1006 			return NETDEV_TX_OK;
1007 		}
1008 		desc_set_phys_addr(lp, phys, cur_p);
1009 		cur_p->cntrl = skb_frag_size(frag);
1010 	}
1011 
1012 	cur_p->cntrl |= XAXIDMA_BD_CTRL_TXEOF_MASK;
1013 	cur_p->skb = skb;
1014 
1015 	tail_p = lp->tx_bd_p + sizeof(*lp->tx_bd_v) * new_tail_ptr;
1016 	if (++new_tail_ptr >= lp->tx_bd_num)
1017 		new_tail_ptr = 0;
1018 	WRITE_ONCE(lp->tx_bd_tail, new_tail_ptr);
1019 
1020 	/* Start the transfer */
1021 	axienet_dma_out_addr(lp, XAXIDMA_TX_TDESC_OFFSET, tail_p);
1022 
1023 	/* Stop queue if next transmit may not have space */
1024 	if (axienet_check_tx_bd_space(lp, MAX_SKB_FRAGS + 1)) {
1025 		netif_stop_queue(ndev);
1026 
1027 		/* Matches barrier in axienet_tx_poll */
1028 		smp_mb();
1029 
1030 		/* Space might have just been freed - check again */
1031 		if (!axienet_check_tx_bd_space(lp, MAX_SKB_FRAGS + 1))
1032 			netif_wake_queue(ndev);
1033 	}
1034 
1035 	return NETDEV_TX_OK;
1036 }
1037 
1038 /**
1039  * axienet_dma_rx_cb - DMA engine callback for RX channel.
1040  * @data:       Pointer to the skbuf_dma_descriptor structure.
1041  * @result:     error reporting through dmaengine_result.
1042  * This function is called by dmaengine driver for RX channel to notify
1043  * that the packet is received.
1044  */
1045 static void axienet_dma_rx_cb(void *data, const struct dmaengine_result *result)
1046 {
1047 	struct skbuf_dma_descriptor *skbuf_dma;
1048 	size_t meta_len, meta_max_len, rx_len;
1049 	struct axienet_local *lp = data;
1050 	struct sk_buff *skb;
1051 	u32 *app_metadata;
1052 
1053 	skbuf_dma = axienet_get_rx_desc(lp, lp->rx_ring_tail++);
1054 	skb = skbuf_dma->skb;
1055 	app_metadata = dmaengine_desc_get_metadata_ptr(skbuf_dma->desc, &meta_len,
1056 						       &meta_max_len);
1057 	dma_unmap_single(lp->dev, skbuf_dma->dma_address, lp->max_frm_size,
1058 			 DMA_FROM_DEVICE);
1059 	/* TODO: Derive app word index programmatically */
1060 	rx_len = (app_metadata[LEN_APP] & 0xFFFF);
1061 	skb_put(skb, rx_len);
1062 	skb->protocol = eth_type_trans(skb, lp->ndev);
1063 	skb->ip_summed = CHECKSUM_NONE;
1064 
1065 	__netif_rx(skb);
1066 	u64_stats_update_begin(&lp->rx_stat_sync);
1067 	u64_stats_add(&lp->rx_packets, 1);
1068 	u64_stats_add(&lp->rx_bytes, rx_len);
1069 	u64_stats_update_end(&lp->rx_stat_sync);
1070 	axienet_rx_submit_desc(lp->ndev);
1071 	dma_async_issue_pending(lp->rx_chan);
1072 }
1073 
1074 /**
1075  * axienet_rx_poll - Triggered by RX ISR to complete the BD processing.
1076  * @napi:	Pointer to NAPI structure.
1077  * @budget:	Max number of RX packets to process.
1078  *
1079  * Return: Number of RX packets processed.
1080  */
1081 static int axienet_rx_poll(struct napi_struct *napi, int budget)
1082 {
1083 	u32 length;
1084 	u32 csumstatus;
1085 	u32 size = 0;
1086 	int packets = 0;
1087 	dma_addr_t tail_p = 0;
1088 	struct axidma_bd *cur_p;
1089 	struct sk_buff *skb, *new_skb;
1090 	struct axienet_local *lp = container_of(napi, struct axienet_local, napi_rx);
1091 
1092 	cur_p = &lp->rx_bd_v[lp->rx_bd_ci];
1093 
1094 	while (packets < budget && (cur_p->status & XAXIDMA_BD_STS_COMPLETE_MASK)) {
1095 		dma_addr_t phys;
1096 
1097 		/* Ensure we see complete descriptor update */
1098 		dma_rmb();
1099 
1100 		skb = cur_p->skb;
1101 		cur_p->skb = NULL;
1102 
1103 		/* skb could be NULL if a previous pass already received the
1104 		 * packet for this slot in the ring, but failed to refill it
1105 		 * with a newly allocated buffer. In this case, don't try to
1106 		 * receive it again.
1107 		 */
1108 		if (likely(skb)) {
1109 			length = cur_p->app4 & 0x0000FFFF;
1110 
1111 			phys = desc_get_phys_addr(lp, cur_p);
1112 			dma_unmap_single(lp->dev, phys, lp->max_frm_size,
1113 					 DMA_FROM_DEVICE);
1114 
1115 			skb_put(skb, length);
1116 			skb->protocol = eth_type_trans(skb, lp->ndev);
1117 			/*skb_checksum_none_assert(skb);*/
1118 			skb->ip_summed = CHECKSUM_NONE;
1119 
1120 			/* if we're doing Rx csum offload, set it up */
1121 			if (lp->features & XAE_FEATURE_FULL_RX_CSUM) {
1122 				csumstatus = (cur_p->app2 &
1123 					      XAE_FULL_CSUM_STATUS_MASK) >> 3;
1124 				if (csumstatus == XAE_IP_TCP_CSUM_VALIDATED ||
1125 				    csumstatus == XAE_IP_UDP_CSUM_VALIDATED) {
1126 					skb->ip_summed = CHECKSUM_UNNECESSARY;
1127 				}
1128 			} else if ((lp->features & XAE_FEATURE_PARTIAL_RX_CSUM) != 0 &&
1129 				   skb->protocol == htons(ETH_P_IP) &&
1130 				   skb->len > 64) {
1131 				skb->csum = be32_to_cpu(cur_p->app3 & 0xFFFF);
1132 				skb->ip_summed = CHECKSUM_COMPLETE;
1133 			}
1134 
1135 			napi_gro_receive(napi, skb);
1136 
1137 			size += length;
1138 			packets++;
1139 		}
1140 
1141 		new_skb = napi_alloc_skb(napi, lp->max_frm_size);
1142 		if (!new_skb)
1143 			break;
1144 
1145 		phys = dma_map_single(lp->dev, new_skb->data,
1146 				      lp->max_frm_size,
1147 				      DMA_FROM_DEVICE);
1148 		if (unlikely(dma_mapping_error(lp->dev, phys))) {
1149 			if (net_ratelimit())
1150 				netdev_err(lp->ndev, "RX DMA mapping error\n");
1151 			dev_kfree_skb(new_skb);
1152 			break;
1153 		}
1154 		desc_set_phys_addr(lp, phys, cur_p);
1155 
1156 		cur_p->cntrl = lp->max_frm_size;
1157 		cur_p->status = 0;
1158 		cur_p->skb = new_skb;
1159 
1160 		/* Only update tail_p to mark this slot as usable after it has
1161 		 * been successfully refilled.
1162 		 */
1163 		tail_p = lp->rx_bd_p + sizeof(*lp->rx_bd_v) * lp->rx_bd_ci;
1164 
1165 		if (++lp->rx_bd_ci >= lp->rx_bd_num)
1166 			lp->rx_bd_ci = 0;
1167 		cur_p = &lp->rx_bd_v[lp->rx_bd_ci];
1168 	}
1169 
1170 	u64_stats_update_begin(&lp->rx_stat_sync);
1171 	u64_stats_add(&lp->rx_packets, packets);
1172 	u64_stats_add(&lp->rx_bytes, size);
1173 	u64_stats_update_end(&lp->rx_stat_sync);
1174 
1175 	if (tail_p)
1176 		axienet_dma_out_addr(lp, XAXIDMA_RX_TDESC_OFFSET, tail_p);
1177 
1178 	if (packets < budget && napi_complete_done(napi, packets)) {
1179 		/* Re-enable RX completion interrupts. This should
1180 		 * cause an immediate interrupt if any RX packets are
1181 		 * already pending.
1182 		 */
1183 		axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, lp->rx_dma_cr);
1184 	}
1185 	return packets;
1186 }
1187 
1188 /**
1189  * axienet_tx_irq - Tx Done Isr.
1190  * @irq:	irq number
1191  * @_ndev:	net_device pointer
1192  *
1193  * Return: IRQ_HANDLED if device generated a TX interrupt, IRQ_NONE otherwise.
1194  *
1195  * This is the Axi DMA Tx done Isr. It invokes NAPI polling to complete the
1196  * TX BD processing.
1197  */
1198 static irqreturn_t axienet_tx_irq(int irq, void *_ndev)
1199 {
1200 	unsigned int status;
1201 	struct net_device *ndev = _ndev;
1202 	struct axienet_local *lp = netdev_priv(ndev);
1203 
1204 	status = axienet_dma_in32(lp, XAXIDMA_TX_SR_OFFSET);
1205 
1206 	if (!(status & XAXIDMA_IRQ_ALL_MASK))
1207 		return IRQ_NONE;
1208 
1209 	axienet_dma_out32(lp, XAXIDMA_TX_SR_OFFSET, status);
1210 
1211 	if (unlikely(status & XAXIDMA_IRQ_ERROR_MASK)) {
1212 		netdev_err(ndev, "DMA Tx error 0x%x\n", status);
1213 		netdev_err(ndev, "Current BD is at: 0x%x%08x\n",
1214 			   (lp->tx_bd_v[lp->tx_bd_ci]).phys_msb,
1215 			   (lp->tx_bd_v[lp->tx_bd_ci]).phys);
1216 		schedule_work(&lp->dma_err_task);
1217 	} else {
1218 		/* Disable further TX completion interrupts and schedule
1219 		 * NAPI to handle the completions.
1220 		 */
1221 		u32 cr = lp->tx_dma_cr;
1222 
1223 		cr &= ~(XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK);
1224 		axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, cr);
1225 
1226 		napi_schedule(&lp->napi_tx);
1227 	}
1228 
1229 	return IRQ_HANDLED;
1230 }
1231 
1232 /**
1233  * axienet_rx_irq - Rx Isr.
1234  * @irq:	irq number
1235  * @_ndev:	net_device pointer
1236  *
1237  * Return: IRQ_HANDLED if device generated a RX interrupt, IRQ_NONE otherwise.
1238  *
1239  * This is the Axi DMA Rx Isr. It invokes NAPI polling to complete the RX BD
1240  * processing.
1241  */
1242 static irqreturn_t axienet_rx_irq(int irq, void *_ndev)
1243 {
1244 	unsigned int status;
1245 	struct net_device *ndev = _ndev;
1246 	struct axienet_local *lp = netdev_priv(ndev);
1247 
1248 	status = axienet_dma_in32(lp, XAXIDMA_RX_SR_OFFSET);
1249 
1250 	if (!(status & XAXIDMA_IRQ_ALL_MASK))
1251 		return IRQ_NONE;
1252 
1253 	axienet_dma_out32(lp, XAXIDMA_RX_SR_OFFSET, status);
1254 
1255 	if (unlikely(status & XAXIDMA_IRQ_ERROR_MASK)) {
1256 		netdev_err(ndev, "DMA Rx error 0x%x\n", status);
1257 		netdev_err(ndev, "Current BD is at: 0x%x%08x\n",
1258 			   (lp->rx_bd_v[lp->rx_bd_ci]).phys_msb,
1259 			   (lp->rx_bd_v[lp->rx_bd_ci]).phys);
1260 		schedule_work(&lp->dma_err_task);
1261 	} else {
1262 		/* Disable further RX completion interrupts and schedule
1263 		 * NAPI receive.
1264 		 */
1265 		u32 cr = lp->rx_dma_cr;
1266 
1267 		cr &= ~(XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK);
1268 		axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr);
1269 
1270 		napi_schedule(&lp->napi_rx);
1271 	}
1272 
1273 	return IRQ_HANDLED;
1274 }
1275 
1276 /**
1277  * axienet_eth_irq - Ethernet core Isr.
1278  * @irq:	irq number
1279  * @_ndev:	net_device pointer
1280  *
1281  * Return: IRQ_HANDLED if device generated a core interrupt, IRQ_NONE otherwise.
1282  *
1283  * Handle miscellaneous conditions indicated by Ethernet core IRQ.
1284  */
1285 static irqreturn_t axienet_eth_irq(int irq, void *_ndev)
1286 {
1287 	struct net_device *ndev = _ndev;
1288 	struct axienet_local *lp = netdev_priv(ndev);
1289 	unsigned int pending;
1290 
1291 	pending = axienet_ior(lp, XAE_IP_OFFSET);
1292 	if (!pending)
1293 		return IRQ_NONE;
1294 
1295 	if (pending & XAE_INT_RXFIFOOVR_MASK)
1296 		ndev->stats.rx_missed_errors++;
1297 
1298 	if (pending & XAE_INT_RXRJECT_MASK)
1299 		ndev->stats.rx_frame_errors++;
1300 
1301 	axienet_iow(lp, XAE_IS_OFFSET, pending);
1302 	return IRQ_HANDLED;
1303 }
1304 
1305 static void axienet_dma_err_handler(struct work_struct *work);
1306 
1307 /**
1308  * axienet_rx_submit_desc - Submit the rx descriptors to dmaengine.
1309  * allocate skbuff, map the scatterlist and obtain a descriptor
1310  * and then add the callback information and submit descriptor.
1311  *
1312  * @ndev:	net_device pointer
1313  *
1314  */
1315 static void axienet_rx_submit_desc(struct net_device *ndev)
1316 {
1317 	struct dma_async_tx_descriptor *dma_rx_desc = NULL;
1318 	struct axienet_local *lp = netdev_priv(ndev);
1319 	struct skbuf_dma_descriptor *skbuf_dma;
1320 	struct sk_buff *skb;
1321 	dma_addr_t addr;
1322 
1323 	skbuf_dma = axienet_get_rx_desc(lp, lp->rx_ring_head);
1324 	if (!skbuf_dma)
1325 		return;
1326 
1327 	lp->rx_ring_head++;
1328 	skb = netdev_alloc_skb(ndev, lp->max_frm_size);
1329 	if (!skb)
1330 		return;
1331 
1332 	sg_init_table(skbuf_dma->sgl, 1);
1333 	addr = dma_map_single(lp->dev, skb->data, lp->max_frm_size, DMA_FROM_DEVICE);
1334 	if (unlikely(dma_mapping_error(lp->dev, addr))) {
1335 		if (net_ratelimit())
1336 			netdev_err(ndev, "DMA mapping error\n");
1337 		goto rx_submit_err_free_skb;
1338 	}
1339 	sg_dma_address(skbuf_dma->sgl) = addr;
1340 	sg_dma_len(skbuf_dma->sgl) = lp->max_frm_size;
1341 	dma_rx_desc = dmaengine_prep_slave_sg(lp->rx_chan, skbuf_dma->sgl,
1342 					      1, DMA_DEV_TO_MEM,
1343 					      DMA_PREP_INTERRUPT);
1344 	if (!dma_rx_desc)
1345 		goto rx_submit_err_unmap_skb;
1346 
1347 	skbuf_dma->skb = skb;
1348 	skbuf_dma->dma_address = sg_dma_address(skbuf_dma->sgl);
1349 	skbuf_dma->desc = dma_rx_desc;
1350 	dma_rx_desc->callback_param = lp;
1351 	dma_rx_desc->callback_result = axienet_dma_rx_cb;
1352 	dmaengine_submit(dma_rx_desc);
1353 
1354 	return;
1355 
1356 rx_submit_err_unmap_skb:
1357 	dma_unmap_single(lp->dev, addr, lp->max_frm_size, DMA_FROM_DEVICE);
1358 rx_submit_err_free_skb:
1359 	dev_kfree_skb(skb);
1360 }
1361 
1362 /**
1363  * axienet_init_dmaengine - init the dmaengine code.
1364  * @ndev:       Pointer to net_device structure
1365  *
1366  * Return: 0, on success.
1367  *          non-zero error value on failure
1368  *
1369  * This is the dmaengine initialization code.
1370  */
1371 static int axienet_init_dmaengine(struct net_device *ndev)
1372 {
1373 	struct axienet_local *lp = netdev_priv(ndev);
1374 	struct skbuf_dma_descriptor *skbuf_dma;
1375 	int i, ret;
1376 
1377 	lp->tx_chan = dma_request_chan(lp->dev, "tx_chan0");
1378 	if (IS_ERR(lp->tx_chan)) {
1379 		dev_err(lp->dev, "No Ethernet DMA (TX) channel found\n");
1380 		return PTR_ERR(lp->tx_chan);
1381 	}
1382 
1383 	lp->rx_chan = dma_request_chan(lp->dev, "rx_chan0");
1384 	if (IS_ERR(lp->rx_chan)) {
1385 		ret = PTR_ERR(lp->rx_chan);
1386 		dev_err(lp->dev, "No Ethernet DMA (RX) channel found\n");
1387 		goto err_dma_release_tx;
1388 	}
1389 
1390 	lp->tx_ring_tail = 0;
1391 	lp->tx_ring_head = 0;
1392 	lp->rx_ring_tail = 0;
1393 	lp->rx_ring_head = 0;
1394 	lp->tx_skb_ring = kcalloc(TX_BD_NUM_MAX, sizeof(*lp->tx_skb_ring),
1395 				  GFP_KERNEL);
1396 	if (!lp->tx_skb_ring) {
1397 		ret = -ENOMEM;
1398 		goto err_dma_release_rx;
1399 	}
1400 	for (i = 0; i < TX_BD_NUM_MAX; i++) {
1401 		skbuf_dma = kzalloc(sizeof(*skbuf_dma), GFP_KERNEL);
1402 		if (!skbuf_dma) {
1403 			ret = -ENOMEM;
1404 			goto err_free_tx_skb_ring;
1405 		}
1406 		lp->tx_skb_ring[i] = skbuf_dma;
1407 	}
1408 
1409 	lp->rx_skb_ring = kcalloc(RX_BUF_NUM_DEFAULT, sizeof(*lp->rx_skb_ring),
1410 				  GFP_KERNEL);
1411 	if (!lp->rx_skb_ring) {
1412 		ret = -ENOMEM;
1413 		goto err_free_tx_skb_ring;
1414 	}
1415 	for (i = 0; i < RX_BUF_NUM_DEFAULT; i++) {
1416 		skbuf_dma = kzalloc(sizeof(*skbuf_dma), GFP_KERNEL);
1417 		if (!skbuf_dma) {
1418 			ret = -ENOMEM;
1419 			goto err_free_rx_skb_ring;
1420 		}
1421 		lp->rx_skb_ring[i] = skbuf_dma;
1422 	}
1423 	/* TODO: Instead of BD_NUM_DEFAULT use runtime support */
1424 	for (i = 0; i < RX_BUF_NUM_DEFAULT; i++)
1425 		axienet_rx_submit_desc(ndev);
1426 	dma_async_issue_pending(lp->rx_chan);
1427 
1428 	return 0;
1429 
1430 err_free_rx_skb_ring:
1431 	for (i = 0; i < RX_BUF_NUM_DEFAULT; i++)
1432 		kfree(lp->rx_skb_ring[i]);
1433 	kfree(lp->rx_skb_ring);
1434 err_free_tx_skb_ring:
1435 	for (i = 0; i < TX_BD_NUM_MAX; i++)
1436 		kfree(lp->tx_skb_ring[i]);
1437 	kfree(lp->tx_skb_ring);
1438 err_dma_release_rx:
1439 	dma_release_channel(lp->rx_chan);
1440 err_dma_release_tx:
1441 	dma_release_channel(lp->tx_chan);
1442 	return ret;
1443 }
1444 
1445 /**
1446  * axienet_init_legacy_dma - init the dma legacy code.
1447  * @ndev:       Pointer to net_device structure
1448  *
1449  * Return: 0, on success.
1450  *          non-zero error value on failure
1451  *
1452  * This is the dma  initialization code. It also allocates interrupt
1453  * service routines, enables the interrupt lines and ISR handling.
1454  *
1455  */
1456 static int axienet_init_legacy_dma(struct net_device *ndev)
1457 {
1458 	int ret;
1459 	struct axienet_local *lp = netdev_priv(ndev);
1460 
1461 	/* Enable worker thread for Axi DMA error handling */
1462 	INIT_WORK(&lp->dma_err_task, axienet_dma_err_handler);
1463 
1464 	napi_enable(&lp->napi_rx);
1465 	napi_enable(&lp->napi_tx);
1466 
1467 	/* Enable interrupts for Axi DMA Tx */
1468 	ret = request_irq(lp->tx_irq, axienet_tx_irq, IRQF_SHARED,
1469 			  ndev->name, ndev);
1470 	if (ret)
1471 		goto err_tx_irq;
1472 	/* Enable interrupts for Axi DMA Rx */
1473 	ret = request_irq(lp->rx_irq, axienet_rx_irq, IRQF_SHARED,
1474 			  ndev->name, ndev);
1475 	if (ret)
1476 		goto err_rx_irq;
1477 	/* Enable interrupts for Axi Ethernet core (if defined) */
1478 	if (lp->eth_irq > 0) {
1479 		ret = request_irq(lp->eth_irq, axienet_eth_irq, IRQF_SHARED,
1480 				  ndev->name, ndev);
1481 		if (ret)
1482 			goto err_eth_irq;
1483 	}
1484 
1485 	return 0;
1486 
1487 err_eth_irq:
1488 	free_irq(lp->rx_irq, ndev);
1489 err_rx_irq:
1490 	free_irq(lp->tx_irq, ndev);
1491 err_tx_irq:
1492 	napi_disable(&lp->napi_tx);
1493 	napi_disable(&lp->napi_rx);
1494 	cancel_work_sync(&lp->dma_err_task);
1495 	dev_err(lp->dev, "request_irq() failed\n");
1496 	return ret;
1497 }
1498 
1499 /**
1500  * axienet_open - Driver open routine.
1501  * @ndev:	Pointer to net_device structure
1502  *
1503  * Return: 0, on success.
1504  *	    non-zero error value on failure
1505  *
1506  * This is the driver open routine. It calls phylink_start to start the
1507  * PHY device.
1508  * It also allocates interrupt service routines, enables the interrupt lines
1509  * and ISR handling. Axi Ethernet core is reset through Axi DMA core. Buffer
1510  * descriptors are initialized.
1511  */
1512 static int axienet_open(struct net_device *ndev)
1513 {
1514 	int ret;
1515 	struct axienet_local *lp = netdev_priv(ndev);
1516 
1517 	dev_dbg(&ndev->dev, "%s\n", __func__);
1518 
1519 	/* When we do an Axi Ethernet reset, it resets the complete core
1520 	 * including the MDIO. MDIO must be disabled before resetting.
1521 	 * Hold MDIO bus lock to avoid MDIO accesses during the reset.
1522 	 */
1523 	axienet_lock_mii(lp);
1524 	ret = axienet_device_reset(ndev);
1525 	axienet_unlock_mii(lp);
1526 
1527 	ret = phylink_of_phy_connect(lp->phylink, lp->dev->of_node, 0);
1528 	if (ret) {
1529 		dev_err(lp->dev, "phylink_of_phy_connect() failed: %d\n", ret);
1530 		return ret;
1531 	}
1532 
1533 	phylink_start(lp->phylink);
1534 
1535 	if (lp->use_dmaengine) {
1536 		/* Enable interrupts for Axi Ethernet core (if defined) */
1537 		if (lp->eth_irq > 0) {
1538 			ret = request_irq(lp->eth_irq, axienet_eth_irq, IRQF_SHARED,
1539 					  ndev->name, ndev);
1540 			if (ret)
1541 				goto err_phy;
1542 		}
1543 
1544 		ret = axienet_init_dmaengine(ndev);
1545 		if (ret < 0)
1546 			goto err_free_eth_irq;
1547 	} else {
1548 		ret = axienet_init_legacy_dma(ndev);
1549 		if (ret)
1550 			goto err_phy;
1551 	}
1552 
1553 	return 0;
1554 
1555 err_free_eth_irq:
1556 	if (lp->eth_irq > 0)
1557 		free_irq(lp->eth_irq, ndev);
1558 err_phy:
1559 	phylink_stop(lp->phylink);
1560 	phylink_disconnect_phy(lp->phylink);
1561 	return ret;
1562 }
1563 
1564 /**
1565  * axienet_stop - Driver stop routine.
1566  * @ndev:	Pointer to net_device structure
1567  *
1568  * Return: 0, on success.
1569  *
1570  * This is the driver stop routine. It calls phylink_disconnect to stop the PHY
1571  * device. It also removes the interrupt handlers and disables the interrupts.
1572  * The Axi DMA Tx/Rx BDs are released.
1573  */
1574 static int axienet_stop(struct net_device *ndev)
1575 {
1576 	struct axienet_local *lp = netdev_priv(ndev);
1577 	int i;
1578 
1579 	dev_dbg(&ndev->dev, "axienet_close()\n");
1580 
1581 	if (!lp->use_dmaengine) {
1582 		napi_disable(&lp->napi_tx);
1583 		napi_disable(&lp->napi_rx);
1584 	}
1585 
1586 	phylink_stop(lp->phylink);
1587 	phylink_disconnect_phy(lp->phylink);
1588 
1589 	axienet_setoptions(ndev, lp->options &
1590 			   ~(XAE_OPTION_TXEN | XAE_OPTION_RXEN));
1591 
1592 	if (!lp->use_dmaengine) {
1593 		axienet_dma_stop(lp);
1594 		cancel_work_sync(&lp->dma_err_task);
1595 		free_irq(lp->tx_irq, ndev);
1596 		free_irq(lp->rx_irq, ndev);
1597 		axienet_dma_bd_release(ndev);
1598 	} else {
1599 		dmaengine_terminate_sync(lp->tx_chan);
1600 		dmaengine_synchronize(lp->tx_chan);
1601 		dmaengine_terminate_sync(lp->rx_chan);
1602 		dmaengine_synchronize(lp->rx_chan);
1603 
1604 		for (i = 0; i < TX_BD_NUM_MAX; i++)
1605 			kfree(lp->tx_skb_ring[i]);
1606 		kfree(lp->tx_skb_ring);
1607 		for (i = 0; i < RX_BUF_NUM_DEFAULT; i++)
1608 			kfree(lp->rx_skb_ring[i]);
1609 		kfree(lp->rx_skb_ring);
1610 
1611 		dma_release_channel(lp->rx_chan);
1612 		dma_release_channel(lp->tx_chan);
1613 	}
1614 
1615 	axienet_iow(lp, XAE_IE_OFFSET, 0);
1616 
1617 	if (lp->eth_irq > 0)
1618 		free_irq(lp->eth_irq, ndev);
1619 	return 0;
1620 }
1621 
1622 /**
1623  * axienet_change_mtu - Driver change mtu routine.
1624  * @ndev:	Pointer to net_device structure
1625  * @new_mtu:	New mtu value to be applied
1626  *
1627  * Return: Always returns 0 (success).
1628  *
1629  * This is the change mtu driver routine. It checks if the Axi Ethernet
1630  * hardware supports jumbo frames before changing the mtu. This can be
1631  * called only when the device is not up.
1632  */
1633 static int axienet_change_mtu(struct net_device *ndev, int new_mtu)
1634 {
1635 	struct axienet_local *lp = netdev_priv(ndev);
1636 
1637 	if (netif_running(ndev))
1638 		return -EBUSY;
1639 
1640 	if ((new_mtu + VLAN_ETH_HLEN +
1641 		XAE_TRL_SIZE) > lp->rxmem)
1642 		return -EINVAL;
1643 
1644 	WRITE_ONCE(ndev->mtu, new_mtu);
1645 
1646 	return 0;
1647 }
1648 
1649 #ifdef CONFIG_NET_POLL_CONTROLLER
1650 /**
1651  * axienet_poll_controller - Axi Ethernet poll mechanism.
1652  * @ndev:	Pointer to net_device structure
1653  *
1654  * This implements Rx/Tx ISR poll mechanisms. The interrupts are disabled prior
1655  * to polling the ISRs and are enabled back after the polling is done.
1656  */
1657 static void axienet_poll_controller(struct net_device *ndev)
1658 {
1659 	struct axienet_local *lp = netdev_priv(ndev);
1660 	disable_irq(lp->tx_irq);
1661 	disable_irq(lp->rx_irq);
1662 	axienet_rx_irq(lp->tx_irq, ndev);
1663 	axienet_tx_irq(lp->rx_irq, ndev);
1664 	enable_irq(lp->tx_irq);
1665 	enable_irq(lp->rx_irq);
1666 }
1667 #endif
1668 
1669 static int axienet_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
1670 {
1671 	struct axienet_local *lp = netdev_priv(dev);
1672 
1673 	if (!netif_running(dev))
1674 		return -EINVAL;
1675 
1676 	return phylink_mii_ioctl(lp->phylink, rq, cmd);
1677 }
1678 
1679 static void
1680 axienet_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
1681 {
1682 	struct axienet_local *lp = netdev_priv(dev);
1683 	unsigned int start;
1684 
1685 	netdev_stats_to_stats64(stats, &dev->stats);
1686 
1687 	do {
1688 		start = u64_stats_fetch_begin(&lp->rx_stat_sync);
1689 		stats->rx_packets = u64_stats_read(&lp->rx_packets);
1690 		stats->rx_bytes = u64_stats_read(&lp->rx_bytes);
1691 	} while (u64_stats_fetch_retry(&lp->rx_stat_sync, start));
1692 
1693 	do {
1694 		start = u64_stats_fetch_begin(&lp->tx_stat_sync);
1695 		stats->tx_packets = u64_stats_read(&lp->tx_packets);
1696 		stats->tx_bytes = u64_stats_read(&lp->tx_bytes);
1697 	} while (u64_stats_fetch_retry(&lp->tx_stat_sync, start));
1698 }
1699 
1700 static const struct net_device_ops axienet_netdev_ops = {
1701 	.ndo_open = axienet_open,
1702 	.ndo_stop = axienet_stop,
1703 	.ndo_start_xmit = axienet_start_xmit,
1704 	.ndo_get_stats64 = axienet_get_stats64,
1705 	.ndo_change_mtu	= axienet_change_mtu,
1706 	.ndo_set_mac_address = netdev_set_mac_address,
1707 	.ndo_validate_addr = eth_validate_addr,
1708 	.ndo_eth_ioctl = axienet_ioctl,
1709 	.ndo_set_rx_mode = axienet_set_multicast_list,
1710 #ifdef CONFIG_NET_POLL_CONTROLLER
1711 	.ndo_poll_controller = axienet_poll_controller,
1712 #endif
1713 };
1714 
1715 static const struct net_device_ops axienet_netdev_dmaengine_ops = {
1716 	.ndo_open = axienet_open,
1717 	.ndo_stop = axienet_stop,
1718 	.ndo_start_xmit = axienet_start_xmit_dmaengine,
1719 	.ndo_get_stats64 = axienet_get_stats64,
1720 	.ndo_change_mtu	= axienet_change_mtu,
1721 	.ndo_set_mac_address = netdev_set_mac_address,
1722 	.ndo_validate_addr = eth_validate_addr,
1723 	.ndo_eth_ioctl = axienet_ioctl,
1724 	.ndo_set_rx_mode = axienet_set_multicast_list,
1725 };
1726 
1727 /**
1728  * axienet_ethtools_get_drvinfo - Get various Axi Ethernet driver information.
1729  * @ndev:	Pointer to net_device structure
1730  * @ed:		Pointer to ethtool_drvinfo structure
1731  *
1732  * This implements ethtool command for getting the driver information.
1733  * Issue "ethtool -i ethX" under linux prompt to execute this function.
1734  */
1735 static void axienet_ethtools_get_drvinfo(struct net_device *ndev,
1736 					 struct ethtool_drvinfo *ed)
1737 {
1738 	strscpy(ed->driver, DRIVER_NAME, sizeof(ed->driver));
1739 	strscpy(ed->version, DRIVER_VERSION, sizeof(ed->version));
1740 }
1741 
1742 /**
1743  * axienet_ethtools_get_regs_len - Get the total regs length present in the
1744  *				   AxiEthernet core.
1745  * @ndev:	Pointer to net_device structure
1746  *
1747  * This implements ethtool command for getting the total register length
1748  * information.
1749  *
1750  * Return: the total regs length
1751  */
1752 static int axienet_ethtools_get_regs_len(struct net_device *ndev)
1753 {
1754 	return sizeof(u32) * AXIENET_REGS_N;
1755 }
1756 
1757 /**
1758  * axienet_ethtools_get_regs - Dump the contents of all registers present
1759  *			       in AxiEthernet core.
1760  * @ndev:	Pointer to net_device structure
1761  * @regs:	Pointer to ethtool_regs structure
1762  * @ret:	Void pointer used to return the contents of the registers.
1763  *
1764  * This implements ethtool command for getting the Axi Ethernet register dump.
1765  * Issue "ethtool -d ethX" to execute this function.
1766  */
1767 static void axienet_ethtools_get_regs(struct net_device *ndev,
1768 				      struct ethtool_regs *regs, void *ret)
1769 {
1770 	u32 *data = (u32 *)ret;
1771 	size_t len = sizeof(u32) * AXIENET_REGS_N;
1772 	struct axienet_local *lp = netdev_priv(ndev);
1773 
1774 	regs->version = 0;
1775 	regs->len = len;
1776 
1777 	memset(data, 0, len);
1778 	data[0] = axienet_ior(lp, XAE_RAF_OFFSET);
1779 	data[1] = axienet_ior(lp, XAE_TPF_OFFSET);
1780 	data[2] = axienet_ior(lp, XAE_IFGP_OFFSET);
1781 	data[3] = axienet_ior(lp, XAE_IS_OFFSET);
1782 	data[4] = axienet_ior(lp, XAE_IP_OFFSET);
1783 	data[5] = axienet_ior(lp, XAE_IE_OFFSET);
1784 	data[6] = axienet_ior(lp, XAE_TTAG_OFFSET);
1785 	data[7] = axienet_ior(lp, XAE_RTAG_OFFSET);
1786 	data[8] = axienet_ior(lp, XAE_UAWL_OFFSET);
1787 	data[9] = axienet_ior(lp, XAE_UAWU_OFFSET);
1788 	data[10] = axienet_ior(lp, XAE_TPID0_OFFSET);
1789 	data[11] = axienet_ior(lp, XAE_TPID1_OFFSET);
1790 	data[12] = axienet_ior(lp, XAE_PPST_OFFSET);
1791 	data[13] = axienet_ior(lp, XAE_RCW0_OFFSET);
1792 	data[14] = axienet_ior(lp, XAE_RCW1_OFFSET);
1793 	data[15] = axienet_ior(lp, XAE_TC_OFFSET);
1794 	data[16] = axienet_ior(lp, XAE_FCC_OFFSET);
1795 	data[17] = axienet_ior(lp, XAE_EMMC_OFFSET);
1796 	data[18] = axienet_ior(lp, XAE_PHYC_OFFSET);
1797 	data[19] = axienet_ior(lp, XAE_MDIO_MC_OFFSET);
1798 	data[20] = axienet_ior(lp, XAE_MDIO_MCR_OFFSET);
1799 	data[21] = axienet_ior(lp, XAE_MDIO_MWD_OFFSET);
1800 	data[22] = axienet_ior(lp, XAE_MDIO_MRD_OFFSET);
1801 	data[27] = axienet_ior(lp, XAE_UAW0_OFFSET);
1802 	data[28] = axienet_ior(lp, XAE_UAW1_OFFSET);
1803 	data[29] = axienet_ior(lp, XAE_FMI_OFFSET);
1804 	data[30] = axienet_ior(lp, XAE_AF0_OFFSET);
1805 	data[31] = axienet_ior(lp, XAE_AF1_OFFSET);
1806 	if (!lp->use_dmaengine) {
1807 		data[32] = axienet_dma_in32(lp, XAXIDMA_TX_CR_OFFSET);
1808 		data[33] = axienet_dma_in32(lp, XAXIDMA_TX_SR_OFFSET);
1809 		data[34] = axienet_dma_in32(lp, XAXIDMA_TX_CDESC_OFFSET);
1810 		data[35] = axienet_dma_in32(lp, XAXIDMA_TX_TDESC_OFFSET);
1811 		data[36] = axienet_dma_in32(lp, XAXIDMA_RX_CR_OFFSET);
1812 		data[37] = axienet_dma_in32(lp, XAXIDMA_RX_SR_OFFSET);
1813 		data[38] = axienet_dma_in32(lp, XAXIDMA_RX_CDESC_OFFSET);
1814 		data[39] = axienet_dma_in32(lp, XAXIDMA_RX_TDESC_OFFSET);
1815 	}
1816 }
1817 
1818 static void
1819 axienet_ethtools_get_ringparam(struct net_device *ndev,
1820 			       struct ethtool_ringparam *ering,
1821 			       struct kernel_ethtool_ringparam *kernel_ering,
1822 			       struct netlink_ext_ack *extack)
1823 {
1824 	struct axienet_local *lp = netdev_priv(ndev);
1825 
1826 	ering->rx_max_pending = RX_BD_NUM_MAX;
1827 	ering->rx_mini_max_pending = 0;
1828 	ering->rx_jumbo_max_pending = 0;
1829 	ering->tx_max_pending = TX_BD_NUM_MAX;
1830 	ering->rx_pending = lp->rx_bd_num;
1831 	ering->rx_mini_pending = 0;
1832 	ering->rx_jumbo_pending = 0;
1833 	ering->tx_pending = lp->tx_bd_num;
1834 }
1835 
1836 static int
1837 axienet_ethtools_set_ringparam(struct net_device *ndev,
1838 			       struct ethtool_ringparam *ering,
1839 			       struct kernel_ethtool_ringparam *kernel_ering,
1840 			       struct netlink_ext_ack *extack)
1841 {
1842 	struct axienet_local *lp = netdev_priv(ndev);
1843 
1844 	if (ering->rx_pending > RX_BD_NUM_MAX ||
1845 	    ering->rx_mini_pending ||
1846 	    ering->rx_jumbo_pending ||
1847 	    ering->tx_pending < TX_BD_NUM_MIN ||
1848 	    ering->tx_pending > TX_BD_NUM_MAX)
1849 		return -EINVAL;
1850 
1851 	if (netif_running(ndev))
1852 		return -EBUSY;
1853 
1854 	lp->rx_bd_num = ering->rx_pending;
1855 	lp->tx_bd_num = ering->tx_pending;
1856 	return 0;
1857 }
1858 
1859 /**
1860  * axienet_ethtools_get_pauseparam - Get the pause parameter setting for
1861  *				     Tx and Rx paths.
1862  * @ndev:	Pointer to net_device structure
1863  * @epauseparm:	Pointer to ethtool_pauseparam structure.
1864  *
1865  * This implements ethtool command for getting axi ethernet pause frame
1866  * setting. Issue "ethtool -a ethX" to execute this function.
1867  */
1868 static void
1869 axienet_ethtools_get_pauseparam(struct net_device *ndev,
1870 				struct ethtool_pauseparam *epauseparm)
1871 {
1872 	struct axienet_local *lp = netdev_priv(ndev);
1873 
1874 	phylink_ethtool_get_pauseparam(lp->phylink, epauseparm);
1875 }
1876 
1877 /**
1878  * axienet_ethtools_set_pauseparam - Set device pause parameter(flow control)
1879  *				     settings.
1880  * @ndev:	Pointer to net_device structure
1881  * @epauseparm:Pointer to ethtool_pauseparam structure
1882  *
1883  * This implements ethtool command for enabling flow control on Rx and Tx
1884  * paths. Issue "ethtool -A ethX tx on|off" under linux prompt to execute this
1885  * function.
1886  *
1887  * Return: 0 on success, -EFAULT if device is running
1888  */
1889 static int
1890 axienet_ethtools_set_pauseparam(struct net_device *ndev,
1891 				struct ethtool_pauseparam *epauseparm)
1892 {
1893 	struct axienet_local *lp = netdev_priv(ndev);
1894 
1895 	return phylink_ethtool_set_pauseparam(lp->phylink, epauseparm);
1896 }
1897 
1898 /**
1899  * axienet_ethtools_get_coalesce - Get DMA interrupt coalescing count.
1900  * @ndev:	Pointer to net_device structure
1901  * @ecoalesce:	Pointer to ethtool_coalesce structure
1902  * @kernel_coal: ethtool CQE mode setting structure
1903  * @extack:	extack for reporting error messages
1904  *
1905  * This implements ethtool command for getting the DMA interrupt coalescing
1906  * count on Tx and Rx paths. Issue "ethtool -c ethX" under linux prompt to
1907  * execute this function.
1908  *
1909  * Return: 0 always
1910  */
1911 static int
1912 axienet_ethtools_get_coalesce(struct net_device *ndev,
1913 			      struct ethtool_coalesce *ecoalesce,
1914 			      struct kernel_ethtool_coalesce *kernel_coal,
1915 			      struct netlink_ext_ack *extack)
1916 {
1917 	struct axienet_local *lp = netdev_priv(ndev);
1918 
1919 	ecoalesce->rx_max_coalesced_frames = lp->coalesce_count_rx;
1920 	ecoalesce->rx_coalesce_usecs = lp->coalesce_usec_rx;
1921 	ecoalesce->tx_max_coalesced_frames = lp->coalesce_count_tx;
1922 	ecoalesce->tx_coalesce_usecs = lp->coalesce_usec_tx;
1923 	return 0;
1924 }
1925 
1926 /**
1927  * axienet_ethtools_set_coalesce - Set DMA interrupt coalescing count.
1928  * @ndev:	Pointer to net_device structure
1929  * @ecoalesce:	Pointer to ethtool_coalesce structure
1930  * @kernel_coal: ethtool CQE mode setting structure
1931  * @extack:	extack for reporting error messages
1932  *
1933  * This implements ethtool command for setting the DMA interrupt coalescing
1934  * count on Tx and Rx paths. Issue "ethtool -C ethX rx-frames 5" under linux
1935  * prompt to execute this function.
1936  *
1937  * Return: 0, on success, Non-zero error value on failure.
1938  */
1939 static int
1940 axienet_ethtools_set_coalesce(struct net_device *ndev,
1941 			      struct ethtool_coalesce *ecoalesce,
1942 			      struct kernel_ethtool_coalesce *kernel_coal,
1943 			      struct netlink_ext_ack *extack)
1944 {
1945 	struct axienet_local *lp = netdev_priv(ndev);
1946 
1947 	if (netif_running(ndev)) {
1948 		NL_SET_ERR_MSG(extack,
1949 			       "Please stop netif before applying configuration");
1950 		return -EBUSY;
1951 	}
1952 
1953 	if (ecoalesce->rx_max_coalesced_frames)
1954 		lp->coalesce_count_rx = ecoalesce->rx_max_coalesced_frames;
1955 	if (ecoalesce->rx_coalesce_usecs)
1956 		lp->coalesce_usec_rx = ecoalesce->rx_coalesce_usecs;
1957 	if (ecoalesce->tx_max_coalesced_frames)
1958 		lp->coalesce_count_tx = ecoalesce->tx_max_coalesced_frames;
1959 	if (ecoalesce->tx_coalesce_usecs)
1960 		lp->coalesce_usec_tx = ecoalesce->tx_coalesce_usecs;
1961 
1962 	return 0;
1963 }
1964 
1965 static int
1966 axienet_ethtools_get_link_ksettings(struct net_device *ndev,
1967 				    struct ethtool_link_ksettings *cmd)
1968 {
1969 	struct axienet_local *lp = netdev_priv(ndev);
1970 
1971 	return phylink_ethtool_ksettings_get(lp->phylink, cmd);
1972 }
1973 
1974 static int
1975 axienet_ethtools_set_link_ksettings(struct net_device *ndev,
1976 				    const struct ethtool_link_ksettings *cmd)
1977 {
1978 	struct axienet_local *lp = netdev_priv(ndev);
1979 
1980 	return phylink_ethtool_ksettings_set(lp->phylink, cmd);
1981 }
1982 
1983 static int axienet_ethtools_nway_reset(struct net_device *dev)
1984 {
1985 	struct axienet_local *lp = netdev_priv(dev);
1986 
1987 	return phylink_ethtool_nway_reset(lp->phylink);
1988 }
1989 
1990 static const struct ethtool_ops axienet_ethtool_ops = {
1991 	.supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES |
1992 				     ETHTOOL_COALESCE_USECS,
1993 	.get_drvinfo    = axienet_ethtools_get_drvinfo,
1994 	.get_regs_len   = axienet_ethtools_get_regs_len,
1995 	.get_regs       = axienet_ethtools_get_regs,
1996 	.get_link       = ethtool_op_get_link,
1997 	.get_ringparam	= axienet_ethtools_get_ringparam,
1998 	.set_ringparam	= axienet_ethtools_set_ringparam,
1999 	.get_pauseparam = axienet_ethtools_get_pauseparam,
2000 	.set_pauseparam = axienet_ethtools_set_pauseparam,
2001 	.get_coalesce   = axienet_ethtools_get_coalesce,
2002 	.set_coalesce   = axienet_ethtools_set_coalesce,
2003 	.get_link_ksettings = axienet_ethtools_get_link_ksettings,
2004 	.set_link_ksettings = axienet_ethtools_set_link_ksettings,
2005 	.nway_reset	= axienet_ethtools_nway_reset,
2006 };
2007 
2008 static struct axienet_local *pcs_to_axienet_local(struct phylink_pcs *pcs)
2009 {
2010 	return container_of(pcs, struct axienet_local, pcs);
2011 }
2012 
2013 static void axienet_pcs_get_state(struct phylink_pcs *pcs,
2014 				  struct phylink_link_state *state)
2015 {
2016 	struct mdio_device *pcs_phy = pcs_to_axienet_local(pcs)->pcs_phy;
2017 
2018 	phylink_mii_c22_pcs_get_state(pcs_phy, state);
2019 }
2020 
2021 static void axienet_pcs_an_restart(struct phylink_pcs *pcs)
2022 {
2023 	struct mdio_device *pcs_phy = pcs_to_axienet_local(pcs)->pcs_phy;
2024 
2025 	phylink_mii_c22_pcs_an_restart(pcs_phy);
2026 }
2027 
2028 static int axienet_pcs_config(struct phylink_pcs *pcs, unsigned int neg_mode,
2029 			      phy_interface_t interface,
2030 			      const unsigned long *advertising,
2031 			      bool permit_pause_to_mac)
2032 {
2033 	struct mdio_device *pcs_phy = pcs_to_axienet_local(pcs)->pcs_phy;
2034 	struct net_device *ndev = pcs_to_axienet_local(pcs)->ndev;
2035 	struct axienet_local *lp = netdev_priv(ndev);
2036 	int ret;
2037 
2038 	if (lp->switch_x_sgmii) {
2039 		ret = mdiodev_write(pcs_phy, XLNX_MII_STD_SELECT_REG,
2040 				    interface == PHY_INTERFACE_MODE_SGMII ?
2041 					XLNX_MII_STD_SELECT_SGMII : 0);
2042 		if (ret < 0) {
2043 			netdev_warn(ndev,
2044 				    "Failed to switch PHY interface: %d\n",
2045 				    ret);
2046 			return ret;
2047 		}
2048 	}
2049 
2050 	ret = phylink_mii_c22_pcs_config(pcs_phy, interface, advertising,
2051 					 neg_mode);
2052 	if (ret < 0)
2053 		netdev_warn(ndev, "Failed to configure PCS: %d\n", ret);
2054 
2055 	return ret;
2056 }
2057 
2058 static const struct phylink_pcs_ops axienet_pcs_ops = {
2059 	.pcs_get_state = axienet_pcs_get_state,
2060 	.pcs_config = axienet_pcs_config,
2061 	.pcs_an_restart = axienet_pcs_an_restart,
2062 };
2063 
2064 static struct phylink_pcs *axienet_mac_select_pcs(struct phylink_config *config,
2065 						  phy_interface_t interface)
2066 {
2067 	struct net_device *ndev = to_net_dev(config->dev);
2068 	struct axienet_local *lp = netdev_priv(ndev);
2069 
2070 	if (interface == PHY_INTERFACE_MODE_1000BASEX ||
2071 	    interface ==  PHY_INTERFACE_MODE_SGMII)
2072 		return &lp->pcs;
2073 
2074 	return NULL;
2075 }
2076 
2077 static void axienet_mac_config(struct phylink_config *config, unsigned int mode,
2078 			       const struct phylink_link_state *state)
2079 {
2080 	/* nothing meaningful to do */
2081 }
2082 
2083 static void axienet_mac_link_down(struct phylink_config *config,
2084 				  unsigned int mode,
2085 				  phy_interface_t interface)
2086 {
2087 	/* nothing meaningful to do */
2088 }
2089 
2090 static void axienet_mac_link_up(struct phylink_config *config,
2091 				struct phy_device *phy,
2092 				unsigned int mode, phy_interface_t interface,
2093 				int speed, int duplex,
2094 				bool tx_pause, bool rx_pause)
2095 {
2096 	struct net_device *ndev = to_net_dev(config->dev);
2097 	struct axienet_local *lp = netdev_priv(ndev);
2098 	u32 emmc_reg, fcc_reg;
2099 
2100 	emmc_reg = axienet_ior(lp, XAE_EMMC_OFFSET);
2101 	emmc_reg &= ~XAE_EMMC_LINKSPEED_MASK;
2102 
2103 	switch (speed) {
2104 	case SPEED_1000:
2105 		emmc_reg |= XAE_EMMC_LINKSPD_1000;
2106 		break;
2107 	case SPEED_100:
2108 		emmc_reg |= XAE_EMMC_LINKSPD_100;
2109 		break;
2110 	case SPEED_10:
2111 		emmc_reg |= XAE_EMMC_LINKSPD_10;
2112 		break;
2113 	default:
2114 		dev_err(&ndev->dev,
2115 			"Speed other than 10, 100 or 1Gbps is not supported\n");
2116 		break;
2117 	}
2118 
2119 	axienet_iow(lp, XAE_EMMC_OFFSET, emmc_reg);
2120 
2121 	fcc_reg = axienet_ior(lp, XAE_FCC_OFFSET);
2122 	if (tx_pause)
2123 		fcc_reg |= XAE_FCC_FCTX_MASK;
2124 	else
2125 		fcc_reg &= ~XAE_FCC_FCTX_MASK;
2126 	if (rx_pause)
2127 		fcc_reg |= XAE_FCC_FCRX_MASK;
2128 	else
2129 		fcc_reg &= ~XAE_FCC_FCRX_MASK;
2130 	axienet_iow(lp, XAE_FCC_OFFSET, fcc_reg);
2131 }
2132 
2133 static const struct phylink_mac_ops axienet_phylink_ops = {
2134 	.mac_select_pcs = axienet_mac_select_pcs,
2135 	.mac_config = axienet_mac_config,
2136 	.mac_link_down = axienet_mac_link_down,
2137 	.mac_link_up = axienet_mac_link_up,
2138 };
2139 
2140 /**
2141  * axienet_dma_err_handler - Work queue task for Axi DMA Error
2142  * @work:	pointer to work_struct
2143  *
2144  * Resets the Axi DMA and Axi Ethernet devices, and reconfigures the
2145  * Tx/Rx BDs.
2146  */
2147 static void axienet_dma_err_handler(struct work_struct *work)
2148 {
2149 	u32 i;
2150 	u32 axienet_status;
2151 	struct axidma_bd *cur_p;
2152 	struct axienet_local *lp = container_of(work, struct axienet_local,
2153 						dma_err_task);
2154 	struct net_device *ndev = lp->ndev;
2155 
2156 	napi_disable(&lp->napi_tx);
2157 	napi_disable(&lp->napi_rx);
2158 
2159 	axienet_setoptions(ndev, lp->options &
2160 			   ~(XAE_OPTION_TXEN | XAE_OPTION_RXEN));
2161 
2162 	axienet_dma_stop(lp);
2163 
2164 	for (i = 0; i < lp->tx_bd_num; i++) {
2165 		cur_p = &lp->tx_bd_v[i];
2166 		if (cur_p->cntrl) {
2167 			dma_addr_t addr = desc_get_phys_addr(lp, cur_p);
2168 
2169 			dma_unmap_single(lp->dev, addr,
2170 					 (cur_p->cntrl &
2171 					  XAXIDMA_BD_CTRL_LENGTH_MASK),
2172 					 DMA_TO_DEVICE);
2173 		}
2174 		if (cur_p->skb)
2175 			dev_kfree_skb_irq(cur_p->skb);
2176 		cur_p->phys = 0;
2177 		cur_p->phys_msb = 0;
2178 		cur_p->cntrl = 0;
2179 		cur_p->status = 0;
2180 		cur_p->app0 = 0;
2181 		cur_p->app1 = 0;
2182 		cur_p->app2 = 0;
2183 		cur_p->app3 = 0;
2184 		cur_p->app4 = 0;
2185 		cur_p->skb = NULL;
2186 	}
2187 
2188 	for (i = 0; i < lp->rx_bd_num; i++) {
2189 		cur_p = &lp->rx_bd_v[i];
2190 		cur_p->status = 0;
2191 		cur_p->app0 = 0;
2192 		cur_p->app1 = 0;
2193 		cur_p->app2 = 0;
2194 		cur_p->app3 = 0;
2195 		cur_p->app4 = 0;
2196 	}
2197 
2198 	lp->tx_bd_ci = 0;
2199 	lp->tx_bd_tail = 0;
2200 	lp->rx_bd_ci = 0;
2201 
2202 	axienet_dma_start(lp);
2203 
2204 	axienet_status = axienet_ior(lp, XAE_RCW1_OFFSET);
2205 	axienet_status &= ~XAE_RCW1_RX_MASK;
2206 	axienet_iow(lp, XAE_RCW1_OFFSET, axienet_status);
2207 
2208 	axienet_status = axienet_ior(lp, XAE_IP_OFFSET);
2209 	if (axienet_status & XAE_INT_RXRJECT_MASK)
2210 		axienet_iow(lp, XAE_IS_OFFSET, XAE_INT_RXRJECT_MASK);
2211 	axienet_iow(lp, XAE_IE_OFFSET, lp->eth_irq > 0 ?
2212 		    XAE_INT_RECV_ERROR_MASK : 0);
2213 	axienet_iow(lp, XAE_FCC_OFFSET, XAE_FCC_FCRX_MASK);
2214 
2215 	/* Sync default options with HW but leave receiver and
2216 	 * transmitter disabled.
2217 	 */
2218 	axienet_setoptions(ndev, lp->options &
2219 			   ~(XAE_OPTION_TXEN | XAE_OPTION_RXEN));
2220 	axienet_set_mac_address(ndev, NULL);
2221 	axienet_set_multicast_list(ndev);
2222 	napi_enable(&lp->napi_rx);
2223 	napi_enable(&lp->napi_tx);
2224 	axienet_setoptions(ndev, lp->options);
2225 }
2226 
2227 /**
2228  * axienet_probe - Axi Ethernet probe function.
2229  * @pdev:	Pointer to platform device structure.
2230  *
2231  * Return: 0, on success
2232  *	    Non-zero error value on failure.
2233  *
2234  * This is the probe routine for Axi Ethernet driver. This is called before
2235  * any other driver routines are invoked. It allocates and sets up the Ethernet
2236  * device. Parses through device tree and populates fields of
2237  * axienet_local. It registers the Ethernet device.
2238  */
2239 static int axienet_probe(struct platform_device *pdev)
2240 {
2241 	int ret;
2242 	struct device_node *np;
2243 	struct axienet_local *lp;
2244 	struct net_device *ndev;
2245 	struct resource *ethres;
2246 	u8 mac_addr[ETH_ALEN];
2247 	int addr_width = 32;
2248 	u32 value;
2249 
2250 	ndev = alloc_etherdev(sizeof(*lp));
2251 	if (!ndev)
2252 		return -ENOMEM;
2253 
2254 	platform_set_drvdata(pdev, ndev);
2255 
2256 	SET_NETDEV_DEV(ndev, &pdev->dev);
2257 	ndev->features = NETIF_F_SG;
2258 	ndev->ethtool_ops = &axienet_ethtool_ops;
2259 
2260 	/* MTU range: 64 - 9000 */
2261 	ndev->min_mtu = 64;
2262 	ndev->max_mtu = XAE_JUMBO_MTU;
2263 
2264 	lp = netdev_priv(ndev);
2265 	lp->ndev = ndev;
2266 	lp->dev = &pdev->dev;
2267 	lp->options = XAE_OPTION_DEFAULTS;
2268 	lp->rx_bd_num = RX_BD_NUM_DEFAULT;
2269 	lp->tx_bd_num = TX_BD_NUM_DEFAULT;
2270 
2271 	u64_stats_init(&lp->rx_stat_sync);
2272 	u64_stats_init(&lp->tx_stat_sync);
2273 
2274 	lp->axi_clk = devm_clk_get_optional(&pdev->dev, "s_axi_lite_clk");
2275 	if (!lp->axi_clk) {
2276 		/* For backward compatibility, if named AXI clock is not present,
2277 		 * treat the first clock specified as the AXI clock.
2278 		 */
2279 		lp->axi_clk = devm_clk_get_optional(&pdev->dev, NULL);
2280 	}
2281 	if (IS_ERR(lp->axi_clk)) {
2282 		ret = PTR_ERR(lp->axi_clk);
2283 		goto free_netdev;
2284 	}
2285 	ret = clk_prepare_enable(lp->axi_clk);
2286 	if (ret) {
2287 		dev_err(&pdev->dev, "Unable to enable AXI clock: %d\n", ret);
2288 		goto free_netdev;
2289 	}
2290 
2291 	lp->misc_clks[0].id = "axis_clk";
2292 	lp->misc_clks[1].id = "ref_clk";
2293 	lp->misc_clks[2].id = "mgt_clk";
2294 
2295 	ret = devm_clk_bulk_get_optional(&pdev->dev, XAE_NUM_MISC_CLOCKS, lp->misc_clks);
2296 	if (ret)
2297 		goto cleanup_clk;
2298 
2299 	ret = clk_bulk_prepare_enable(XAE_NUM_MISC_CLOCKS, lp->misc_clks);
2300 	if (ret)
2301 		goto cleanup_clk;
2302 
2303 	/* Map device registers */
2304 	lp->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &ethres);
2305 	if (IS_ERR(lp->regs)) {
2306 		ret = PTR_ERR(lp->regs);
2307 		goto cleanup_clk;
2308 	}
2309 	lp->regs_start = ethres->start;
2310 
2311 	/* Setup checksum offload, but default to off if not specified */
2312 	lp->features = 0;
2313 
2314 	ret = of_property_read_u32(pdev->dev.of_node, "xlnx,txcsum", &value);
2315 	if (!ret) {
2316 		switch (value) {
2317 		case 1:
2318 			lp->csum_offload_on_tx_path =
2319 				XAE_FEATURE_PARTIAL_TX_CSUM;
2320 			lp->features |= XAE_FEATURE_PARTIAL_TX_CSUM;
2321 			/* Can checksum TCP/UDP over IPv4. */
2322 			ndev->features |= NETIF_F_IP_CSUM;
2323 			break;
2324 		case 2:
2325 			lp->csum_offload_on_tx_path =
2326 				XAE_FEATURE_FULL_TX_CSUM;
2327 			lp->features |= XAE_FEATURE_FULL_TX_CSUM;
2328 			/* Can checksum TCP/UDP over IPv4. */
2329 			ndev->features |= NETIF_F_IP_CSUM;
2330 			break;
2331 		default:
2332 			lp->csum_offload_on_tx_path = XAE_NO_CSUM_OFFLOAD;
2333 		}
2334 	}
2335 	ret = of_property_read_u32(pdev->dev.of_node, "xlnx,rxcsum", &value);
2336 	if (!ret) {
2337 		switch (value) {
2338 		case 1:
2339 			lp->csum_offload_on_rx_path =
2340 				XAE_FEATURE_PARTIAL_RX_CSUM;
2341 			lp->features |= XAE_FEATURE_PARTIAL_RX_CSUM;
2342 			break;
2343 		case 2:
2344 			lp->csum_offload_on_rx_path =
2345 				XAE_FEATURE_FULL_RX_CSUM;
2346 			lp->features |= XAE_FEATURE_FULL_RX_CSUM;
2347 			break;
2348 		default:
2349 			lp->csum_offload_on_rx_path = XAE_NO_CSUM_OFFLOAD;
2350 		}
2351 	}
2352 	/* For supporting jumbo frames, the Axi Ethernet hardware must have
2353 	 * a larger Rx/Tx Memory. Typically, the size must be large so that
2354 	 * we can enable jumbo option and start supporting jumbo frames.
2355 	 * Here we check for memory allocated for Rx/Tx in the hardware from
2356 	 * the device-tree and accordingly set flags.
2357 	 */
2358 	of_property_read_u32(pdev->dev.of_node, "xlnx,rxmem", &lp->rxmem);
2359 
2360 	lp->switch_x_sgmii = of_property_read_bool(pdev->dev.of_node,
2361 						   "xlnx,switch-x-sgmii");
2362 
2363 	/* Start with the proprietary, and broken phy_type */
2364 	ret = of_property_read_u32(pdev->dev.of_node, "xlnx,phy-type", &value);
2365 	if (!ret) {
2366 		netdev_warn(ndev, "Please upgrade your device tree binary blob to use phy-mode");
2367 		switch (value) {
2368 		case XAE_PHY_TYPE_MII:
2369 			lp->phy_mode = PHY_INTERFACE_MODE_MII;
2370 			break;
2371 		case XAE_PHY_TYPE_GMII:
2372 			lp->phy_mode = PHY_INTERFACE_MODE_GMII;
2373 			break;
2374 		case XAE_PHY_TYPE_RGMII_2_0:
2375 			lp->phy_mode = PHY_INTERFACE_MODE_RGMII_ID;
2376 			break;
2377 		case XAE_PHY_TYPE_SGMII:
2378 			lp->phy_mode = PHY_INTERFACE_MODE_SGMII;
2379 			break;
2380 		case XAE_PHY_TYPE_1000BASE_X:
2381 			lp->phy_mode = PHY_INTERFACE_MODE_1000BASEX;
2382 			break;
2383 		default:
2384 			ret = -EINVAL;
2385 			goto cleanup_clk;
2386 		}
2387 	} else {
2388 		ret = of_get_phy_mode(pdev->dev.of_node, &lp->phy_mode);
2389 		if (ret)
2390 			goto cleanup_clk;
2391 	}
2392 	if (lp->switch_x_sgmii && lp->phy_mode != PHY_INTERFACE_MODE_SGMII &&
2393 	    lp->phy_mode != PHY_INTERFACE_MODE_1000BASEX) {
2394 		dev_err(&pdev->dev, "xlnx,switch-x-sgmii only supported with SGMII or 1000BaseX\n");
2395 		ret = -EINVAL;
2396 		goto cleanup_clk;
2397 	}
2398 
2399 	if (!of_find_property(pdev->dev.of_node, "dmas", NULL)) {
2400 		/* Find the DMA node, map the DMA registers, and decode the DMA IRQs */
2401 		np = of_parse_phandle(pdev->dev.of_node, "axistream-connected", 0);
2402 
2403 		if (np) {
2404 			struct resource dmares;
2405 
2406 			ret = of_address_to_resource(np, 0, &dmares);
2407 			if (ret) {
2408 				dev_err(&pdev->dev,
2409 					"unable to get DMA resource\n");
2410 				of_node_put(np);
2411 				goto cleanup_clk;
2412 			}
2413 			lp->dma_regs = devm_ioremap_resource(&pdev->dev,
2414 							     &dmares);
2415 			lp->rx_irq = irq_of_parse_and_map(np, 1);
2416 			lp->tx_irq = irq_of_parse_and_map(np, 0);
2417 			of_node_put(np);
2418 			lp->eth_irq = platform_get_irq_optional(pdev, 0);
2419 		} else {
2420 			/* Check for these resources directly on the Ethernet node. */
2421 			lp->dma_regs = devm_platform_get_and_ioremap_resource(pdev, 1, NULL);
2422 			lp->rx_irq = platform_get_irq(pdev, 1);
2423 			lp->tx_irq = platform_get_irq(pdev, 0);
2424 			lp->eth_irq = platform_get_irq_optional(pdev, 2);
2425 		}
2426 		if (IS_ERR(lp->dma_regs)) {
2427 			dev_err(&pdev->dev, "could not map DMA regs\n");
2428 			ret = PTR_ERR(lp->dma_regs);
2429 			goto cleanup_clk;
2430 		}
2431 		if (lp->rx_irq <= 0 || lp->tx_irq <= 0) {
2432 			dev_err(&pdev->dev, "could not determine irqs\n");
2433 			ret = -ENOMEM;
2434 			goto cleanup_clk;
2435 		}
2436 
2437 		/* Reset core now that clocks are enabled, prior to accessing MDIO */
2438 		ret = __axienet_device_reset(lp);
2439 		if (ret)
2440 			goto cleanup_clk;
2441 
2442 		/* Autodetect the need for 64-bit DMA pointers.
2443 		 * When the IP is configured for a bus width bigger than 32 bits,
2444 		 * writing the MSB registers is mandatory, even if they are all 0.
2445 		 * We can detect this case by writing all 1's to one such register
2446 		 * and see if that sticks: when the IP is configured for 32 bits
2447 		 * only, those registers are RES0.
2448 		 * Those MSB registers were introduced in IP v7.1, which we check first.
2449 		 */
2450 		if ((axienet_ior(lp, XAE_ID_OFFSET) >> 24) >= 0x9) {
2451 			void __iomem *desc = lp->dma_regs + XAXIDMA_TX_CDESC_OFFSET + 4;
2452 
2453 			iowrite32(0x0, desc);
2454 			if (ioread32(desc) == 0) {	/* sanity check */
2455 				iowrite32(0xffffffff, desc);
2456 				if (ioread32(desc) > 0) {
2457 					lp->features |= XAE_FEATURE_DMA_64BIT;
2458 					addr_width = 64;
2459 					dev_info(&pdev->dev,
2460 						 "autodetected 64-bit DMA range\n");
2461 				}
2462 				iowrite32(0x0, desc);
2463 			}
2464 		}
2465 		if (!IS_ENABLED(CONFIG_64BIT) && lp->features & XAE_FEATURE_DMA_64BIT) {
2466 			dev_err(&pdev->dev, "64-bit addressable DMA is not compatible with 32-bit archecture\n");
2467 			ret = -EINVAL;
2468 			goto cleanup_clk;
2469 		}
2470 
2471 		ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(addr_width));
2472 		if (ret) {
2473 			dev_err(&pdev->dev, "No suitable DMA available\n");
2474 			goto cleanup_clk;
2475 		}
2476 		netif_napi_add(ndev, &lp->napi_rx, axienet_rx_poll);
2477 		netif_napi_add(ndev, &lp->napi_tx, axienet_tx_poll);
2478 	} else {
2479 		struct xilinx_vdma_config cfg;
2480 		struct dma_chan *tx_chan;
2481 
2482 		lp->eth_irq = platform_get_irq_optional(pdev, 0);
2483 		if (lp->eth_irq < 0 && lp->eth_irq != -ENXIO) {
2484 			ret = lp->eth_irq;
2485 			goto cleanup_clk;
2486 		}
2487 		tx_chan = dma_request_chan(lp->dev, "tx_chan0");
2488 		if (IS_ERR(tx_chan)) {
2489 			ret = PTR_ERR(tx_chan);
2490 			dev_err_probe(lp->dev, ret, "No Ethernet DMA (TX) channel found\n");
2491 			goto cleanup_clk;
2492 		}
2493 
2494 		cfg.reset = 1;
2495 		/* As name says VDMA but it has support for DMA channel reset */
2496 		ret = xilinx_vdma_channel_set_config(tx_chan, &cfg);
2497 		if (ret < 0) {
2498 			dev_err(&pdev->dev, "Reset channel failed\n");
2499 			dma_release_channel(tx_chan);
2500 			goto cleanup_clk;
2501 		}
2502 
2503 		dma_release_channel(tx_chan);
2504 		lp->use_dmaengine = 1;
2505 	}
2506 
2507 	if (lp->use_dmaengine)
2508 		ndev->netdev_ops = &axienet_netdev_dmaengine_ops;
2509 	else
2510 		ndev->netdev_ops = &axienet_netdev_ops;
2511 	/* Check for Ethernet core IRQ (optional) */
2512 	if (lp->eth_irq <= 0)
2513 		dev_info(&pdev->dev, "Ethernet core IRQ not defined\n");
2514 
2515 	/* Retrieve the MAC address */
2516 	ret = of_get_mac_address(pdev->dev.of_node, mac_addr);
2517 	if (!ret) {
2518 		axienet_set_mac_address(ndev, mac_addr);
2519 	} else {
2520 		dev_warn(&pdev->dev, "could not find MAC address property: %d\n",
2521 			 ret);
2522 		axienet_set_mac_address(ndev, NULL);
2523 	}
2524 
2525 	lp->coalesce_count_rx = XAXIDMA_DFT_RX_THRESHOLD;
2526 	lp->coalesce_count_tx = XAXIDMA_DFT_TX_THRESHOLD;
2527 	lp->coalesce_usec_rx = XAXIDMA_DFT_RX_USEC;
2528 	lp->coalesce_usec_tx = XAXIDMA_DFT_TX_USEC;
2529 
2530 	ret = axienet_mdio_setup(lp);
2531 	if (ret)
2532 		dev_warn(&pdev->dev,
2533 			 "error registering MDIO bus: %d\n", ret);
2534 
2535 	if (lp->phy_mode == PHY_INTERFACE_MODE_SGMII ||
2536 	    lp->phy_mode == PHY_INTERFACE_MODE_1000BASEX) {
2537 		np = of_parse_phandle(pdev->dev.of_node, "pcs-handle", 0);
2538 		if (!np) {
2539 			/* Deprecated: Always use "pcs-handle" for pcs_phy.
2540 			 * Falling back to "phy-handle" here is only for
2541 			 * backward compatibility with old device trees.
2542 			 */
2543 			np = of_parse_phandle(pdev->dev.of_node, "phy-handle", 0);
2544 		}
2545 		if (!np) {
2546 			dev_err(&pdev->dev, "pcs-handle (preferred) or phy-handle required for 1000BaseX/SGMII\n");
2547 			ret = -EINVAL;
2548 			goto cleanup_mdio;
2549 		}
2550 		lp->pcs_phy = of_mdio_find_device(np);
2551 		if (!lp->pcs_phy) {
2552 			ret = -EPROBE_DEFER;
2553 			of_node_put(np);
2554 			goto cleanup_mdio;
2555 		}
2556 		of_node_put(np);
2557 		lp->pcs.ops = &axienet_pcs_ops;
2558 		lp->pcs.neg_mode = true;
2559 		lp->pcs.poll = true;
2560 	}
2561 
2562 	lp->phylink_config.dev = &ndev->dev;
2563 	lp->phylink_config.type = PHYLINK_NETDEV;
2564 	lp->phylink_config.mac_capabilities = MAC_SYM_PAUSE | MAC_ASYM_PAUSE |
2565 		MAC_10FD | MAC_100FD | MAC_1000FD;
2566 
2567 	__set_bit(lp->phy_mode, lp->phylink_config.supported_interfaces);
2568 	if (lp->switch_x_sgmii) {
2569 		__set_bit(PHY_INTERFACE_MODE_1000BASEX,
2570 			  lp->phylink_config.supported_interfaces);
2571 		__set_bit(PHY_INTERFACE_MODE_SGMII,
2572 			  lp->phylink_config.supported_interfaces);
2573 	}
2574 
2575 	lp->phylink = phylink_create(&lp->phylink_config, pdev->dev.fwnode,
2576 				     lp->phy_mode,
2577 				     &axienet_phylink_ops);
2578 	if (IS_ERR(lp->phylink)) {
2579 		ret = PTR_ERR(lp->phylink);
2580 		dev_err(&pdev->dev, "phylink_create error (%i)\n", ret);
2581 		goto cleanup_mdio;
2582 	}
2583 
2584 	ret = register_netdev(lp->ndev);
2585 	if (ret) {
2586 		dev_err(lp->dev, "register_netdev() error (%i)\n", ret);
2587 		goto cleanup_phylink;
2588 	}
2589 
2590 	return 0;
2591 
2592 cleanup_phylink:
2593 	phylink_destroy(lp->phylink);
2594 
2595 cleanup_mdio:
2596 	if (lp->pcs_phy)
2597 		put_device(&lp->pcs_phy->dev);
2598 	if (lp->mii_bus)
2599 		axienet_mdio_teardown(lp);
2600 cleanup_clk:
2601 	clk_bulk_disable_unprepare(XAE_NUM_MISC_CLOCKS, lp->misc_clks);
2602 	clk_disable_unprepare(lp->axi_clk);
2603 
2604 free_netdev:
2605 	free_netdev(ndev);
2606 
2607 	return ret;
2608 }
2609 
2610 static void axienet_remove(struct platform_device *pdev)
2611 {
2612 	struct net_device *ndev = platform_get_drvdata(pdev);
2613 	struct axienet_local *lp = netdev_priv(ndev);
2614 
2615 	unregister_netdev(ndev);
2616 
2617 	if (lp->phylink)
2618 		phylink_destroy(lp->phylink);
2619 
2620 	if (lp->pcs_phy)
2621 		put_device(&lp->pcs_phy->dev);
2622 
2623 	axienet_mdio_teardown(lp);
2624 
2625 	clk_bulk_disable_unprepare(XAE_NUM_MISC_CLOCKS, lp->misc_clks);
2626 	clk_disable_unprepare(lp->axi_clk);
2627 
2628 	free_netdev(ndev);
2629 }
2630 
2631 static void axienet_shutdown(struct platform_device *pdev)
2632 {
2633 	struct net_device *ndev = platform_get_drvdata(pdev);
2634 
2635 	rtnl_lock();
2636 	netif_device_detach(ndev);
2637 
2638 	if (netif_running(ndev))
2639 		dev_close(ndev);
2640 
2641 	rtnl_unlock();
2642 }
2643 
2644 static int axienet_suspend(struct device *dev)
2645 {
2646 	struct net_device *ndev = dev_get_drvdata(dev);
2647 
2648 	if (!netif_running(ndev))
2649 		return 0;
2650 
2651 	netif_device_detach(ndev);
2652 
2653 	rtnl_lock();
2654 	axienet_stop(ndev);
2655 	rtnl_unlock();
2656 
2657 	return 0;
2658 }
2659 
2660 static int axienet_resume(struct device *dev)
2661 {
2662 	struct net_device *ndev = dev_get_drvdata(dev);
2663 
2664 	if (!netif_running(ndev))
2665 		return 0;
2666 
2667 	rtnl_lock();
2668 	axienet_open(ndev);
2669 	rtnl_unlock();
2670 
2671 	netif_device_attach(ndev);
2672 
2673 	return 0;
2674 }
2675 
2676 static DEFINE_SIMPLE_DEV_PM_OPS(axienet_pm_ops,
2677 				axienet_suspend, axienet_resume);
2678 
2679 static struct platform_driver axienet_driver = {
2680 	.probe = axienet_probe,
2681 	.remove_new = axienet_remove,
2682 	.shutdown = axienet_shutdown,
2683 	.driver = {
2684 		 .name = "xilinx_axienet",
2685 		 .pm = &axienet_pm_ops,
2686 		 .of_match_table = axienet_of_match,
2687 	},
2688 };
2689 
2690 module_platform_driver(axienet_driver);
2691 
2692 MODULE_DESCRIPTION("Xilinx Axi Ethernet driver");
2693 MODULE_AUTHOR("Xilinx");
2694 MODULE_LICENSE("GPL");
2695