xref: /linux/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
1 /*******************************************************************************
2   This is the driver for the ST MAC 10/100/1000 on-chip Ethernet controllers.
3   ST Ethernet IPs are built around a Synopsys IP Core.
4 
5 	Copyright(C) 2007-2011 STMicroelectronics Ltd
6 
7   This program is free software; you can redistribute it and/or modify it
8   under the terms and conditions of the GNU General Public License,
9   version 2, as published by the Free Software Foundation.
10 
11   This program is distributed in the hope it will be useful, but WITHOUT
12   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14   more details.
15 
16   You should have received a copy of the GNU General Public License along with
17   this program; if not, write to the Free Software Foundation, Inc.,
18   51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19 
20   The full GNU General Public License is included in this distribution in
21   the file called "COPYING".
22 
23   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
24 
25   Documentation available at:
26 	http://www.stlinux.com
27   Support available at:
28 	https://bugzilla.stlinux.com/
29 *******************************************************************************/
30 
31 #include <linux/clk.h>
32 #include <linux/kernel.h>
33 #include <linux/interrupt.h>
34 #include <linux/ip.h>
35 #include <linux/tcp.h>
36 #include <linux/skbuff.h>
37 #include <linux/ethtool.h>
38 #include <linux/if_ether.h>
39 #include <linux/crc32.h>
40 #include <linux/mii.h>
41 #include <linux/if.h>
42 #include <linux/if_vlan.h>
43 #include <linux/dma-mapping.h>
44 #include <linux/slab.h>
45 #include <linux/prefetch.h>
46 #include <linux/pinctrl/consumer.h>
47 #ifdef CONFIG_DEBUG_FS
48 #include <linux/debugfs.h>
49 #include <linux/seq_file.h>
50 #endif /* CONFIG_DEBUG_FS */
51 #include <linux/net_tstamp.h>
52 #include "stmmac_ptp.h"
53 #include "stmmac.h"
54 #include <linux/reset.h>
55 
56 #define STMMAC_ALIGN(x)	L1_CACHE_ALIGN(x)
57 
58 /* Module parameters */
59 #define TX_TIMEO	5000
60 static int watchdog = TX_TIMEO;
61 module_param(watchdog, int, S_IRUGO | S_IWUSR);
62 MODULE_PARM_DESC(watchdog, "Transmit timeout in milliseconds (default 5s)");
63 
64 static int debug = -1;
65 module_param(debug, int, S_IRUGO | S_IWUSR);
66 MODULE_PARM_DESC(debug, "Message Level (-1: default, 0: no output, 16: all)");
67 
68 static int phyaddr = -1;
69 module_param(phyaddr, int, S_IRUGO);
70 MODULE_PARM_DESC(phyaddr, "Physical device address");
71 
72 #define DMA_TX_SIZE 256
73 static int dma_txsize = DMA_TX_SIZE;
74 module_param(dma_txsize, int, S_IRUGO | S_IWUSR);
75 MODULE_PARM_DESC(dma_txsize, "Number of descriptors in the TX list");
76 
77 #define DMA_RX_SIZE 256
78 static int dma_rxsize = DMA_RX_SIZE;
79 module_param(dma_rxsize, int, S_IRUGO | S_IWUSR);
80 MODULE_PARM_DESC(dma_rxsize, "Number of descriptors in the RX list");
81 
82 static int flow_ctrl = FLOW_OFF;
83 module_param(flow_ctrl, int, S_IRUGO | S_IWUSR);
84 MODULE_PARM_DESC(flow_ctrl, "Flow control ability [on/off]");
85 
86 static int pause = PAUSE_TIME;
87 module_param(pause, int, S_IRUGO | S_IWUSR);
88 MODULE_PARM_DESC(pause, "Flow Control Pause Time");
89 
90 #define TC_DEFAULT 64
91 static int tc = TC_DEFAULT;
92 module_param(tc, int, S_IRUGO | S_IWUSR);
93 MODULE_PARM_DESC(tc, "DMA threshold control value");
94 
95 #define	DEFAULT_BUFSIZE	1536
96 static int buf_sz = DEFAULT_BUFSIZE;
97 module_param(buf_sz, int, S_IRUGO | S_IWUSR);
98 MODULE_PARM_DESC(buf_sz, "DMA buffer size");
99 
100 static const u32 default_msg_level = (NETIF_MSG_DRV | NETIF_MSG_PROBE |
101 				      NETIF_MSG_LINK | NETIF_MSG_IFUP |
102 				      NETIF_MSG_IFDOWN | NETIF_MSG_TIMER);
103 
104 #define STMMAC_DEFAULT_LPI_TIMER	1000
105 static int eee_timer = STMMAC_DEFAULT_LPI_TIMER;
106 module_param(eee_timer, int, S_IRUGO | S_IWUSR);
107 MODULE_PARM_DESC(eee_timer, "LPI tx expiration time in msec");
108 #define STMMAC_LPI_T(x) (jiffies + msecs_to_jiffies(x))
109 
110 /* By default the driver will use the ring mode to manage tx and rx descriptors
111  * but passing this value so user can force to use the chain instead of the ring
112  */
113 static unsigned int chain_mode;
114 module_param(chain_mode, int, S_IRUGO);
115 MODULE_PARM_DESC(chain_mode, "To use chain instead of ring mode");
116 
117 static irqreturn_t stmmac_interrupt(int irq, void *dev_id);
118 
119 #ifdef CONFIG_DEBUG_FS
120 static int stmmac_init_fs(struct net_device *dev);
121 static void stmmac_exit_fs(void);
122 #endif
123 
124 #define STMMAC_COAL_TIMER(x) (jiffies + usecs_to_jiffies(x))
125 
126 /**
127  * stmmac_verify_args - verify the driver parameters.
128  * Description: it checks the driver parameters and set a default in case of
129  * errors.
130  */
131 static void stmmac_verify_args(void)
132 {
133 	if (unlikely(watchdog < 0))
134 		watchdog = TX_TIMEO;
135 	if (unlikely(dma_rxsize < 0))
136 		dma_rxsize = DMA_RX_SIZE;
137 	if (unlikely(dma_txsize < 0))
138 		dma_txsize = DMA_TX_SIZE;
139 	if (unlikely((buf_sz < DEFAULT_BUFSIZE) || (buf_sz > BUF_SIZE_16KiB)))
140 		buf_sz = DEFAULT_BUFSIZE;
141 	if (unlikely(flow_ctrl > 1))
142 		flow_ctrl = FLOW_AUTO;
143 	else if (likely(flow_ctrl < 0))
144 		flow_ctrl = FLOW_OFF;
145 	if (unlikely((pause < 0) || (pause > 0xffff)))
146 		pause = PAUSE_TIME;
147 	if (eee_timer < 0)
148 		eee_timer = STMMAC_DEFAULT_LPI_TIMER;
149 }
150 
151 /**
152  * stmmac_clk_csr_set - dynamically set the MDC clock
153  * @priv: driver private structure
154  * Description: this is to dynamically set the MDC clock according to the csr
155  * clock input.
156  * Note:
157  *	If a specific clk_csr value is passed from the platform
158  *	this means that the CSR Clock Range selection cannot be
159  *	changed at run-time and it is fixed (as reported in the driver
160  *	documentation). Viceversa the driver will try to set the MDC
161  *	clock dynamically according to the actual clock input.
162  */
163 static void stmmac_clk_csr_set(struct stmmac_priv *priv)
164 {
165 	u32 clk_rate;
166 
167 	clk_rate = clk_get_rate(priv->stmmac_clk);
168 
169 	/* Platform provided default clk_csr would be assumed valid
170 	 * for all other cases except for the below mentioned ones.
171 	 * For values higher than the IEEE 802.3 specified frequency
172 	 * we can not estimate the proper divider as it is not known
173 	 * the frequency of clk_csr_i. So we do not change the default
174 	 * divider.
175 	 */
176 	if (!(priv->clk_csr & MAC_CSR_H_FRQ_MASK)) {
177 		if (clk_rate < CSR_F_35M)
178 			priv->clk_csr = STMMAC_CSR_20_35M;
179 		else if ((clk_rate >= CSR_F_35M) && (clk_rate < CSR_F_60M))
180 			priv->clk_csr = STMMAC_CSR_35_60M;
181 		else if ((clk_rate >= CSR_F_60M) && (clk_rate < CSR_F_100M))
182 			priv->clk_csr = STMMAC_CSR_60_100M;
183 		else if ((clk_rate >= CSR_F_100M) && (clk_rate < CSR_F_150M))
184 			priv->clk_csr = STMMAC_CSR_100_150M;
185 		else if ((clk_rate >= CSR_F_150M) && (clk_rate < CSR_F_250M))
186 			priv->clk_csr = STMMAC_CSR_150_250M;
187 		else if ((clk_rate >= CSR_F_250M) && (clk_rate < CSR_F_300M))
188 			priv->clk_csr = STMMAC_CSR_250_300M;
189 	}
190 }
191 
192 static void print_pkt(unsigned char *buf, int len)
193 {
194 	pr_debug("len = %d byte, buf addr: 0x%p\n", len, buf);
195 	print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, buf, len);
196 }
197 
198 /* minimum number of free TX descriptors required to wake up TX process */
199 #define STMMAC_TX_THRESH(x)	(x->dma_tx_size/4)
200 
201 static inline u32 stmmac_tx_avail(struct stmmac_priv *priv)
202 {
203 	return priv->dirty_tx + priv->dma_tx_size - priv->cur_tx - 1;
204 }
205 
206 /**
207  * stmmac_hw_fix_mac_speed - callback for speed selection
208  * @priv: driver private structure
209  * Description: on some platforms (e.g. ST), some HW system configuraton
210  * registers have to be set according to the link speed negotiated.
211  */
212 static inline void stmmac_hw_fix_mac_speed(struct stmmac_priv *priv)
213 {
214 	struct phy_device *phydev = priv->phydev;
215 
216 	if (likely(priv->plat->fix_mac_speed))
217 		priv->plat->fix_mac_speed(priv->plat->bsp_priv, phydev->speed);
218 }
219 
220 /**
221  * stmmac_enable_eee_mode - check and enter in LPI mode
222  * @priv: driver private structure
223  * Description: this function is to verify and enter in LPI mode in case of
224  * EEE.
225  */
226 static void stmmac_enable_eee_mode(struct stmmac_priv *priv)
227 {
228 	/* Check and enter in LPI mode */
229 	if ((priv->dirty_tx == priv->cur_tx) &&
230 	    (priv->tx_path_in_lpi_mode == false))
231 		priv->hw->mac->set_eee_mode(priv->hw);
232 }
233 
234 /**
235  * stmmac_disable_eee_mode - disable and exit from LPI mode
236  * @priv: driver private structure
237  * Description: this function is to exit and disable EEE in case of
238  * LPI state is true. This is called by the xmit.
239  */
240 void stmmac_disable_eee_mode(struct stmmac_priv *priv)
241 {
242 	priv->hw->mac->reset_eee_mode(priv->hw);
243 	del_timer_sync(&priv->eee_ctrl_timer);
244 	priv->tx_path_in_lpi_mode = false;
245 }
246 
247 /**
248  * stmmac_eee_ctrl_timer - EEE TX SW timer.
249  * @arg : data hook
250  * Description:
251  *  if there is no data transfer and if we are not in LPI state,
252  *  then MAC Transmitter can be moved to LPI state.
253  */
254 static void stmmac_eee_ctrl_timer(unsigned long arg)
255 {
256 	struct stmmac_priv *priv = (struct stmmac_priv *)arg;
257 
258 	stmmac_enable_eee_mode(priv);
259 	mod_timer(&priv->eee_ctrl_timer, STMMAC_LPI_T(eee_timer));
260 }
261 
262 /**
263  * stmmac_eee_init - init EEE
264  * @priv: driver private structure
265  * Description:
266  *  if the GMAC supports the EEE (from the HW cap reg) and the phy device
267  *  can also manage EEE, this function enable the LPI state and start related
268  *  timer.
269  */
270 bool stmmac_eee_init(struct stmmac_priv *priv)
271 {
272 	char *phy_bus_name = priv->plat->phy_bus_name;
273 	unsigned long flags;
274 	bool ret = false;
275 
276 	/* Using PCS we cannot dial with the phy registers at this stage
277 	 * so we do not support extra feature like EEE.
278 	 */
279 	if ((priv->pcs == STMMAC_PCS_RGMII) || (priv->pcs == STMMAC_PCS_TBI) ||
280 	    (priv->pcs == STMMAC_PCS_RTBI))
281 		goto out;
282 
283 	/* Never init EEE in case of a switch is attached */
284 	if (phy_bus_name && (!strcmp(phy_bus_name, "fixed")))
285 		goto out;
286 
287 	/* MAC core supports the EEE feature. */
288 	if (priv->dma_cap.eee) {
289 		int tx_lpi_timer = priv->tx_lpi_timer;
290 
291 		/* Check if the PHY supports EEE */
292 		if (phy_init_eee(priv->phydev, 1)) {
293 			/* To manage at run-time if the EEE cannot be supported
294 			 * anymore (for example because the lp caps have been
295 			 * changed).
296 			 * In that case the driver disable own timers.
297 			 */
298 			spin_lock_irqsave(&priv->lock, flags);
299 			if (priv->eee_active) {
300 				pr_debug("stmmac: disable EEE\n");
301 				del_timer_sync(&priv->eee_ctrl_timer);
302 				priv->hw->mac->set_eee_timer(priv->hw, 0,
303 							     tx_lpi_timer);
304 			}
305 			priv->eee_active = 0;
306 			spin_unlock_irqrestore(&priv->lock, flags);
307 			goto out;
308 		}
309 		/* Activate the EEE and start timers */
310 		spin_lock_irqsave(&priv->lock, flags);
311 		if (!priv->eee_active) {
312 			priv->eee_active = 1;
313 			init_timer(&priv->eee_ctrl_timer);
314 			priv->eee_ctrl_timer.function = stmmac_eee_ctrl_timer;
315 			priv->eee_ctrl_timer.data = (unsigned long)priv;
316 			priv->eee_ctrl_timer.expires = STMMAC_LPI_T(eee_timer);
317 			add_timer(&priv->eee_ctrl_timer);
318 
319 			priv->hw->mac->set_eee_timer(priv->hw,
320 						     STMMAC_DEFAULT_LIT_LS,
321 						     tx_lpi_timer);
322 		}
323 		/* Set HW EEE according to the speed */
324 		priv->hw->mac->set_eee_pls(priv->hw, priv->phydev->link);
325 
326 		ret = true;
327 		spin_unlock_irqrestore(&priv->lock, flags);
328 
329 		pr_debug("stmmac: Energy-Efficient Ethernet initialized\n");
330 	}
331 out:
332 	return ret;
333 }
334 
335 /* stmmac_get_tx_hwtstamp - get HW TX timestamps
336  * @priv: driver private structure
337  * @entry : descriptor index to be used.
338  * @skb : the socket buffer
339  * Description :
340  * This function will read timestamp from the descriptor & pass it to stack.
341  * and also perform some sanity checks.
342  */
343 static void stmmac_get_tx_hwtstamp(struct stmmac_priv *priv,
344 				   unsigned int entry, struct sk_buff *skb)
345 {
346 	struct skb_shared_hwtstamps shhwtstamp;
347 	u64 ns;
348 	void *desc = NULL;
349 
350 	if (!priv->hwts_tx_en)
351 		return;
352 
353 	/* exit if skb doesn't support hw tstamp */
354 	if (likely(!skb || !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)))
355 		return;
356 
357 	if (priv->adv_ts)
358 		desc = (priv->dma_etx + entry);
359 	else
360 		desc = (priv->dma_tx + entry);
361 
362 	/* check tx tstamp status */
363 	if (!priv->hw->desc->get_tx_timestamp_status((struct dma_desc *)desc))
364 		return;
365 
366 	/* get the valid tstamp */
367 	ns = priv->hw->desc->get_timestamp(desc, priv->adv_ts);
368 
369 	memset(&shhwtstamp, 0, sizeof(struct skb_shared_hwtstamps));
370 	shhwtstamp.hwtstamp = ns_to_ktime(ns);
371 	/* pass tstamp to stack */
372 	skb_tstamp_tx(skb, &shhwtstamp);
373 
374 	return;
375 }
376 
377 /* stmmac_get_rx_hwtstamp - get HW RX timestamps
378  * @priv: driver private structure
379  * @entry : descriptor index to be used.
380  * @skb : the socket buffer
381  * Description :
382  * This function will read received packet's timestamp from the descriptor
383  * and pass it to stack. It also perform some sanity checks.
384  */
385 static void stmmac_get_rx_hwtstamp(struct stmmac_priv *priv,
386 				   unsigned int entry, struct sk_buff *skb)
387 {
388 	struct skb_shared_hwtstamps *shhwtstamp = NULL;
389 	u64 ns;
390 	void *desc = NULL;
391 
392 	if (!priv->hwts_rx_en)
393 		return;
394 
395 	if (priv->adv_ts)
396 		desc = (priv->dma_erx + entry);
397 	else
398 		desc = (priv->dma_rx + entry);
399 
400 	/* exit if rx tstamp is not valid */
401 	if (!priv->hw->desc->get_rx_timestamp_status(desc, priv->adv_ts))
402 		return;
403 
404 	/* get valid tstamp */
405 	ns = priv->hw->desc->get_timestamp(desc, priv->adv_ts);
406 	shhwtstamp = skb_hwtstamps(skb);
407 	memset(shhwtstamp, 0, sizeof(struct skb_shared_hwtstamps));
408 	shhwtstamp->hwtstamp = ns_to_ktime(ns);
409 }
410 
411 /**
412  *  stmmac_hwtstamp_ioctl - control hardware timestamping.
413  *  @dev: device pointer.
414  *  @ifr: An IOCTL specefic structure, that can contain a pointer to
415  *  a proprietary structure used to pass information to the driver.
416  *  Description:
417  *  This function configures the MAC to enable/disable both outgoing(TX)
418  *  and incoming(RX) packets time stamping based on user input.
419  *  Return Value:
420  *  0 on success and an appropriate -ve integer on failure.
421  */
422 static int stmmac_hwtstamp_ioctl(struct net_device *dev, struct ifreq *ifr)
423 {
424 	struct stmmac_priv *priv = netdev_priv(dev);
425 	struct hwtstamp_config config;
426 	struct timespec now;
427 	u64 temp = 0;
428 	u32 ptp_v2 = 0;
429 	u32 tstamp_all = 0;
430 	u32 ptp_over_ipv4_udp = 0;
431 	u32 ptp_over_ipv6_udp = 0;
432 	u32 ptp_over_ethernet = 0;
433 	u32 snap_type_sel = 0;
434 	u32 ts_master_en = 0;
435 	u32 ts_event_en = 0;
436 	u32 value = 0;
437 
438 	if (!(priv->dma_cap.time_stamp || priv->adv_ts)) {
439 		netdev_alert(priv->dev, "No support for HW time stamping\n");
440 		priv->hwts_tx_en = 0;
441 		priv->hwts_rx_en = 0;
442 
443 		return -EOPNOTSUPP;
444 	}
445 
446 	if (copy_from_user(&config, ifr->ifr_data,
447 			   sizeof(struct hwtstamp_config)))
448 		return -EFAULT;
449 
450 	pr_debug("%s config flags:0x%x, tx_type:0x%x, rx_filter:0x%x\n",
451 		 __func__, config.flags, config.tx_type, config.rx_filter);
452 
453 	/* reserved for future extensions */
454 	if (config.flags)
455 		return -EINVAL;
456 
457 	if (config.tx_type != HWTSTAMP_TX_OFF &&
458 	    config.tx_type != HWTSTAMP_TX_ON)
459 		return -ERANGE;
460 
461 	if (priv->adv_ts) {
462 		switch (config.rx_filter) {
463 		case HWTSTAMP_FILTER_NONE:
464 			/* time stamp no incoming packet at all */
465 			config.rx_filter = HWTSTAMP_FILTER_NONE;
466 			break;
467 
468 		case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
469 			/* PTP v1, UDP, any kind of event packet */
470 			config.rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_EVENT;
471 			/* take time stamp for all event messages */
472 			snap_type_sel = PTP_TCR_SNAPTYPSEL_1;
473 
474 			ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
475 			ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
476 			break;
477 
478 		case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
479 			/* PTP v1, UDP, Sync packet */
480 			config.rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_SYNC;
481 			/* take time stamp for SYNC messages only */
482 			ts_event_en = PTP_TCR_TSEVNTENA;
483 
484 			ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
485 			ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
486 			break;
487 
488 		case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
489 			/* PTP v1, UDP, Delay_req packet */
490 			config.rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ;
491 			/* take time stamp for Delay_Req messages only */
492 			ts_master_en = PTP_TCR_TSMSTRENA;
493 			ts_event_en = PTP_TCR_TSEVNTENA;
494 
495 			ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
496 			ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
497 			break;
498 
499 		case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
500 			/* PTP v2, UDP, any kind of event packet */
501 			config.rx_filter = HWTSTAMP_FILTER_PTP_V2_L4_EVENT;
502 			ptp_v2 = PTP_TCR_TSVER2ENA;
503 			/* take time stamp for all event messages */
504 			snap_type_sel = PTP_TCR_SNAPTYPSEL_1;
505 
506 			ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
507 			ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
508 			break;
509 
510 		case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
511 			/* PTP v2, UDP, Sync packet */
512 			config.rx_filter = HWTSTAMP_FILTER_PTP_V2_L4_SYNC;
513 			ptp_v2 = PTP_TCR_TSVER2ENA;
514 			/* take time stamp for SYNC messages only */
515 			ts_event_en = PTP_TCR_TSEVNTENA;
516 
517 			ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
518 			ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
519 			break;
520 
521 		case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
522 			/* PTP v2, UDP, Delay_req packet */
523 			config.rx_filter = HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ;
524 			ptp_v2 = PTP_TCR_TSVER2ENA;
525 			/* take time stamp for Delay_Req messages only */
526 			ts_master_en = PTP_TCR_TSMSTRENA;
527 			ts_event_en = PTP_TCR_TSEVNTENA;
528 
529 			ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
530 			ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
531 			break;
532 
533 		case HWTSTAMP_FILTER_PTP_V2_EVENT:
534 			/* PTP v2/802.AS1 any layer, any kind of event packet */
535 			config.rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
536 			ptp_v2 = PTP_TCR_TSVER2ENA;
537 			/* take time stamp for all event messages */
538 			snap_type_sel = PTP_TCR_SNAPTYPSEL_1;
539 
540 			ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
541 			ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
542 			ptp_over_ethernet = PTP_TCR_TSIPENA;
543 			break;
544 
545 		case HWTSTAMP_FILTER_PTP_V2_SYNC:
546 			/* PTP v2/802.AS1, any layer, Sync packet */
547 			config.rx_filter = HWTSTAMP_FILTER_PTP_V2_SYNC;
548 			ptp_v2 = PTP_TCR_TSVER2ENA;
549 			/* take time stamp for SYNC messages only */
550 			ts_event_en = PTP_TCR_TSEVNTENA;
551 
552 			ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
553 			ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
554 			ptp_over_ethernet = PTP_TCR_TSIPENA;
555 			break;
556 
557 		case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
558 			/* PTP v2/802.AS1, any layer, Delay_req packet */
559 			config.rx_filter = HWTSTAMP_FILTER_PTP_V2_DELAY_REQ;
560 			ptp_v2 = PTP_TCR_TSVER2ENA;
561 			/* take time stamp for Delay_Req messages only */
562 			ts_master_en = PTP_TCR_TSMSTRENA;
563 			ts_event_en = PTP_TCR_TSEVNTENA;
564 
565 			ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
566 			ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
567 			ptp_over_ethernet = PTP_TCR_TSIPENA;
568 			break;
569 
570 		case HWTSTAMP_FILTER_ALL:
571 			/* time stamp any incoming packet */
572 			config.rx_filter = HWTSTAMP_FILTER_ALL;
573 			tstamp_all = PTP_TCR_TSENALL;
574 			break;
575 
576 		default:
577 			return -ERANGE;
578 		}
579 	} else {
580 		switch (config.rx_filter) {
581 		case HWTSTAMP_FILTER_NONE:
582 			config.rx_filter = HWTSTAMP_FILTER_NONE;
583 			break;
584 		default:
585 			/* PTP v1, UDP, any kind of event packet */
586 			config.rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_EVENT;
587 			break;
588 		}
589 	}
590 	priv->hwts_rx_en = ((config.rx_filter == HWTSTAMP_FILTER_NONE) ? 0 : 1);
591 	priv->hwts_tx_en = config.tx_type == HWTSTAMP_TX_ON;
592 
593 	if (!priv->hwts_tx_en && !priv->hwts_rx_en)
594 		priv->hw->ptp->config_hw_tstamping(priv->ioaddr, 0);
595 	else {
596 		value = (PTP_TCR_TSENA | PTP_TCR_TSCFUPDT | PTP_TCR_TSCTRLSSR |
597 			 tstamp_all | ptp_v2 | ptp_over_ethernet |
598 			 ptp_over_ipv6_udp | ptp_over_ipv4_udp | ts_event_en |
599 			 ts_master_en | snap_type_sel);
600 
601 		priv->hw->ptp->config_hw_tstamping(priv->ioaddr, value);
602 
603 		/* program Sub Second Increment reg */
604 		priv->hw->ptp->config_sub_second_increment(priv->ioaddr);
605 
606 		/* calculate default added value:
607 		 * formula is :
608 		 * addend = (2^32)/freq_div_ratio;
609 		 * where, freq_div_ratio = clk_ptp_ref_i/50MHz
610 		 * hence, addend = ((2^32) * 50MHz)/clk_ptp_ref_i;
611 		 * NOTE: clk_ptp_ref_i should be >= 50MHz to
612 		 *       achive 20ns accuracy.
613 		 *
614 		 * 2^x * y == (y << x), hence
615 		 * 2^32 * 50000000 ==> (50000000 << 32)
616 		 */
617 		temp = (u64) (50000000ULL << 32);
618 		priv->default_addend = div_u64(temp, priv->clk_ptp_rate);
619 		priv->hw->ptp->config_addend(priv->ioaddr,
620 					     priv->default_addend);
621 
622 		/* initialize system time */
623 		getnstimeofday(&now);
624 		priv->hw->ptp->init_systime(priv->ioaddr, now.tv_sec,
625 					    now.tv_nsec);
626 	}
627 
628 	return copy_to_user(ifr->ifr_data, &config,
629 			    sizeof(struct hwtstamp_config)) ? -EFAULT : 0;
630 }
631 
632 /**
633  * stmmac_init_ptp - init PTP
634  * @priv: driver private structure
635  * Description: this is to verify if the HW supports the PTPv1 or PTPv2.
636  * This is done by looking at the HW cap. register.
637  * This function also registers the ptp driver.
638  */
639 static int stmmac_init_ptp(struct stmmac_priv *priv)
640 {
641 	if (!(priv->dma_cap.time_stamp || priv->dma_cap.atime_stamp))
642 		return -EOPNOTSUPP;
643 
644 	/* Fall-back to main clock in case of no PTP ref is passed */
645 	priv->clk_ptp_ref = devm_clk_get(priv->device, "clk_ptp_ref");
646 	if (IS_ERR(priv->clk_ptp_ref)) {
647 		priv->clk_ptp_rate = clk_get_rate(priv->stmmac_clk);
648 		priv->clk_ptp_ref = NULL;
649 	} else {
650 		clk_prepare_enable(priv->clk_ptp_ref);
651 		priv->clk_ptp_rate = clk_get_rate(priv->clk_ptp_ref);
652 	}
653 
654 	priv->adv_ts = 0;
655 	if (priv->dma_cap.atime_stamp && priv->extend_desc)
656 		priv->adv_ts = 1;
657 
658 	if (netif_msg_hw(priv) && priv->dma_cap.time_stamp)
659 		pr_debug("IEEE 1588-2002 Time Stamp supported\n");
660 
661 	if (netif_msg_hw(priv) && priv->adv_ts)
662 		pr_debug("IEEE 1588-2008 Advanced Time Stamp supported\n");
663 
664 	priv->hw->ptp = &stmmac_ptp;
665 	priv->hwts_tx_en = 0;
666 	priv->hwts_rx_en = 0;
667 
668 	return stmmac_ptp_register(priv);
669 }
670 
671 static void stmmac_release_ptp(struct stmmac_priv *priv)
672 {
673 	if (priv->clk_ptp_ref)
674 		clk_disable_unprepare(priv->clk_ptp_ref);
675 	stmmac_ptp_unregister(priv);
676 }
677 
678 /**
679  * stmmac_adjust_link - adjusts the link parameters
680  * @dev: net device structure
681  * Description: this is the helper called by the physical abstraction layer
682  * drivers to communicate the phy link status. According the speed and duplex
683  * this driver can invoke registered glue-logic as well.
684  * It also invoke the eee initialization because it could happen when switch
685  * on different networks (that are eee capable).
686  */
687 static void stmmac_adjust_link(struct net_device *dev)
688 {
689 	struct stmmac_priv *priv = netdev_priv(dev);
690 	struct phy_device *phydev = priv->phydev;
691 	unsigned long flags;
692 	int new_state = 0;
693 	unsigned int fc = priv->flow_ctrl, pause_time = priv->pause;
694 
695 	if (phydev == NULL)
696 		return;
697 
698 	spin_lock_irqsave(&priv->lock, flags);
699 
700 	if (phydev->link) {
701 		u32 ctrl = readl(priv->ioaddr + MAC_CTRL_REG);
702 
703 		/* Now we make sure that we can be in full duplex mode.
704 		 * If not, we operate in half-duplex mode. */
705 		if (phydev->duplex != priv->oldduplex) {
706 			new_state = 1;
707 			if (!(phydev->duplex))
708 				ctrl &= ~priv->hw->link.duplex;
709 			else
710 				ctrl |= priv->hw->link.duplex;
711 			priv->oldduplex = phydev->duplex;
712 		}
713 		/* Flow Control operation */
714 		if (phydev->pause)
715 			priv->hw->mac->flow_ctrl(priv->hw, phydev->duplex,
716 						 fc, pause_time);
717 
718 		if (phydev->speed != priv->speed) {
719 			new_state = 1;
720 			switch (phydev->speed) {
721 			case 1000:
722 				if (likely(priv->plat->has_gmac))
723 					ctrl &= ~priv->hw->link.port;
724 				stmmac_hw_fix_mac_speed(priv);
725 				break;
726 			case 100:
727 			case 10:
728 				if (priv->plat->has_gmac) {
729 					ctrl |= priv->hw->link.port;
730 					if (phydev->speed == SPEED_100) {
731 						ctrl |= priv->hw->link.speed;
732 					} else {
733 						ctrl &= ~(priv->hw->link.speed);
734 					}
735 				} else {
736 					ctrl &= ~priv->hw->link.port;
737 				}
738 				stmmac_hw_fix_mac_speed(priv);
739 				break;
740 			default:
741 				if (netif_msg_link(priv))
742 					pr_warn("%s: Speed (%d) not 10/100\n",
743 						dev->name, phydev->speed);
744 				break;
745 			}
746 
747 			priv->speed = phydev->speed;
748 		}
749 
750 		writel(ctrl, priv->ioaddr + MAC_CTRL_REG);
751 
752 		if (!priv->oldlink) {
753 			new_state = 1;
754 			priv->oldlink = 1;
755 		}
756 	} else if (priv->oldlink) {
757 		new_state = 1;
758 		priv->oldlink = 0;
759 		priv->speed = 0;
760 		priv->oldduplex = -1;
761 	}
762 
763 	if (new_state && netif_msg_link(priv))
764 		phy_print_status(phydev);
765 
766 	spin_unlock_irqrestore(&priv->lock, flags);
767 
768 	/* At this stage, it could be needed to setup the EEE or adjust some
769 	 * MAC related HW registers.
770 	 */
771 	priv->eee_enabled = stmmac_eee_init(priv);
772 }
773 
774 /**
775  * stmmac_check_pcs_mode - verify if RGMII/SGMII is supported
776  * @priv: driver private structure
777  * Description: this is to verify if the HW supports the PCS.
778  * Physical Coding Sublayer (PCS) interface that can be used when the MAC is
779  * configured for the TBI, RTBI, or SGMII PHY interface.
780  */
781 static void stmmac_check_pcs_mode(struct stmmac_priv *priv)
782 {
783 	int interface = priv->plat->interface;
784 
785 	if (priv->dma_cap.pcs) {
786 		if ((interface == PHY_INTERFACE_MODE_RGMII) ||
787 		    (interface == PHY_INTERFACE_MODE_RGMII_ID) ||
788 		    (interface == PHY_INTERFACE_MODE_RGMII_RXID) ||
789 		    (interface == PHY_INTERFACE_MODE_RGMII_TXID)) {
790 			pr_debug("STMMAC: PCS RGMII support enable\n");
791 			priv->pcs = STMMAC_PCS_RGMII;
792 		} else if (interface == PHY_INTERFACE_MODE_SGMII) {
793 			pr_debug("STMMAC: PCS SGMII support enable\n");
794 			priv->pcs = STMMAC_PCS_SGMII;
795 		}
796 	}
797 }
798 
799 /**
800  * stmmac_init_phy - PHY initialization
801  * @dev: net device structure
802  * Description: it initializes the driver's PHY state, and attaches the PHY
803  * to the mac driver.
804  *  Return value:
805  *  0 on success
806  */
807 static int stmmac_init_phy(struct net_device *dev)
808 {
809 	struct stmmac_priv *priv = netdev_priv(dev);
810 	struct phy_device *phydev;
811 	char phy_id_fmt[MII_BUS_ID_SIZE + 3];
812 	char bus_id[MII_BUS_ID_SIZE];
813 	int interface = priv->plat->interface;
814 	int max_speed = priv->plat->max_speed;
815 	priv->oldlink = 0;
816 	priv->speed = 0;
817 	priv->oldduplex = -1;
818 
819 	if (priv->plat->phy_bus_name)
820 		snprintf(bus_id, MII_BUS_ID_SIZE, "%s-%x",
821 			 priv->plat->phy_bus_name, priv->plat->bus_id);
822 	else
823 		snprintf(bus_id, MII_BUS_ID_SIZE, "stmmac-%x",
824 			 priv->plat->bus_id);
825 
826 	snprintf(phy_id_fmt, MII_BUS_ID_SIZE + 3, PHY_ID_FMT, bus_id,
827 		 priv->plat->phy_addr);
828 	pr_debug("stmmac_init_phy:  trying to attach to %s\n", phy_id_fmt);
829 
830 	phydev = phy_connect(dev, phy_id_fmt, &stmmac_adjust_link, interface);
831 
832 	if (IS_ERR(phydev)) {
833 		pr_err("%s: Could not attach to PHY\n", dev->name);
834 		return PTR_ERR(phydev);
835 	}
836 
837 	/* Stop Advertising 1000BASE Capability if interface is not GMII */
838 	if ((interface == PHY_INTERFACE_MODE_MII) ||
839 	    (interface == PHY_INTERFACE_MODE_RMII) ||
840 		(max_speed < 1000 && max_speed > 0))
841 		phydev->advertising &= ~(SUPPORTED_1000baseT_Half |
842 					 SUPPORTED_1000baseT_Full);
843 
844 	/*
845 	 * Broken HW is sometimes missing the pull-up resistor on the
846 	 * MDIO line, which results in reads to non-existent devices returning
847 	 * 0 rather than 0xffff. Catch this here and treat 0 as a non-existent
848 	 * device as well.
849 	 * Note: phydev->phy_id is the result of reading the UID PHY registers.
850 	 */
851 	if (phydev->phy_id == 0) {
852 		phy_disconnect(phydev);
853 		return -ENODEV;
854 	}
855 	pr_debug("stmmac_init_phy:  %s: attached to PHY (UID 0x%x)"
856 		 " Link = %d\n", dev->name, phydev->phy_id, phydev->link);
857 
858 	priv->phydev = phydev;
859 
860 	return 0;
861 }
862 
863 /**
864  * stmmac_display_ring - display ring
865  * @head: pointer to the head of the ring passed.
866  * @size: size of the ring.
867  * @extend_desc: to verify if extended descriptors are used.
868  * Description: display the control/status and buffer descriptors.
869  */
870 static void stmmac_display_ring(void *head, int size, int extend_desc)
871 {
872 	int i;
873 	struct dma_extended_desc *ep = (struct dma_extended_desc *)head;
874 	struct dma_desc *p = (struct dma_desc *)head;
875 
876 	for (i = 0; i < size; i++) {
877 		u64 x;
878 		if (extend_desc) {
879 			x = *(u64 *) ep;
880 			pr_info("%d [0x%x]: 0x%x 0x%x 0x%x 0x%x\n",
881 				i, (unsigned int)virt_to_phys(ep),
882 				(unsigned int)x, (unsigned int)(x >> 32),
883 				ep->basic.des2, ep->basic.des3);
884 			ep++;
885 		} else {
886 			x = *(u64 *) p;
887 			pr_info("%d [0x%x]: 0x%x 0x%x 0x%x 0x%x",
888 				i, (unsigned int)virt_to_phys(p),
889 				(unsigned int)x, (unsigned int)(x >> 32),
890 				p->des2, p->des3);
891 			p++;
892 		}
893 		pr_info("\n");
894 	}
895 }
896 
897 static void stmmac_display_rings(struct stmmac_priv *priv)
898 {
899 	unsigned int txsize = priv->dma_tx_size;
900 	unsigned int rxsize = priv->dma_rx_size;
901 
902 	if (priv->extend_desc) {
903 		pr_info("Extended RX descriptor ring:\n");
904 		stmmac_display_ring((void *)priv->dma_erx, rxsize, 1);
905 		pr_info("Extended TX descriptor ring:\n");
906 		stmmac_display_ring((void *)priv->dma_etx, txsize, 1);
907 	} else {
908 		pr_info("RX descriptor ring:\n");
909 		stmmac_display_ring((void *)priv->dma_rx, rxsize, 0);
910 		pr_info("TX descriptor ring:\n");
911 		stmmac_display_ring((void *)priv->dma_tx, txsize, 0);
912 	}
913 }
914 
915 static int stmmac_set_bfsize(int mtu, int bufsize)
916 {
917 	int ret = bufsize;
918 
919 	if (mtu >= BUF_SIZE_4KiB)
920 		ret = BUF_SIZE_8KiB;
921 	else if (mtu >= BUF_SIZE_2KiB)
922 		ret = BUF_SIZE_4KiB;
923 	else if (mtu > DEFAULT_BUFSIZE)
924 		ret = BUF_SIZE_2KiB;
925 	else
926 		ret = DEFAULT_BUFSIZE;
927 
928 	return ret;
929 }
930 
931 /**
932  * stmmac_clear_descriptors - clear descriptors
933  * @priv: driver private structure
934  * Description: this function is called to clear the tx and rx descriptors
935  * in case of both basic and extended descriptors are used.
936  */
937 static void stmmac_clear_descriptors(struct stmmac_priv *priv)
938 {
939 	int i;
940 	unsigned int txsize = priv->dma_tx_size;
941 	unsigned int rxsize = priv->dma_rx_size;
942 
943 	/* Clear the Rx/Tx descriptors */
944 	for (i = 0; i < rxsize; i++)
945 		if (priv->extend_desc)
946 			priv->hw->desc->init_rx_desc(&priv->dma_erx[i].basic,
947 						     priv->use_riwt, priv->mode,
948 						     (i == rxsize - 1));
949 		else
950 			priv->hw->desc->init_rx_desc(&priv->dma_rx[i],
951 						     priv->use_riwt, priv->mode,
952 						     (i == rxsize - 1));
953 	for (i = 0; i < txsize; i++)
954 		if (priv->extend_desc)
955 			priv->hw->desc->init_tx_desc(&priv->dma_etx[i].basic,
956 						     priv->mode,
957 						     (i == txsize - 1));
958 		else
959 			priv->hw->desc->init_tx_desc(&priv->dma_tx[i],
960 						     priv->mode,
961 						     (i == txsize - 1));
962 }
963 
964 /**
965  * stmmac_init_rx_buffers - init the RX descriptor buffer.
966  * @priv: driver private structure
967  * @p: descriptor pointer
968  * @i: descriptor index
969  * @flags: gfp flag.
970  * Description: this function is called to allocate a receive buffer, perform
971  * the DMA mapping and init the descriptor.
972  */
973 static int stmmac_init_rx_buffers(struct stmmac_priv *priv, struct dma_desc *p,
974 				  int i, gfp_t flags)
975 {
976 	struct sk_buff *skb;
977 
978 	skb = __netdev_alloc_skb(priv->dev, priv->dma_buf_sz + NET_IP_ALIGN,
979 				 flags);
980 	if (!skb) {
981 		pr_err("%s: Rx init fails; skb is NULL\n", __func__);
982 		return -ENOMEM;
983 	}
984 	skb_reserve(skb, NET_IP_ALIGN);
985 	priv->rx_skbuff[i] = skb;
986 	priv->rx_skbuff_dma[i] = dma_map_single(priv->device, skb->data,
987 						priv->dma_buf_sz,
988 						DMA_FROM_DEVICE);
989 	if (dma_mapping_error(priv->device, priv->rx_skbuff_dma[i])) {
990 		pr_err("%s: DMA mapping error\n", __func__);
991 		dev_kfree_skb_any(skb);
992 		return -EINVAL;
993 	}
994 
995 	p->des2 = priv->rx_skbuff_dma[i];
996 
997 	if ((priv->hw->mode->init_desc3) &&
998 	    (priv->dma_buf_sz == BUF_SIZE_16KiB))
999 		priv->hw->mode->init_desc3(p);
1000 
1001 	return 0;
1002 }
1003 
1004 static void stmmac_free_rx_buffers(struct stmmac_priv *priv, int i)
1005 {
1006 	if (priv->rx_skbuff[i]) {
1007 		dma_unmap_single(priv->device, priv->rx_skbuff_dma[i],
1008 				 priv->dma_buf_sz, DMA_FROM_DEVICE);
1009 		dev_kfree_skb_any(priv->rx_skbuff[i]);
1010 	}
1011 	priv->rx_skbuff[i] = NULL;
1012 }
1013 
1014 /**
1015  * init_dma_desc_rings - init the RX/TX descriptor rings
1016  * @dev: net device structure
1017  * @flags: gfp flag.
1018  * Description: this function initializes the DMA RX/TX descriptors
1019  * and allocates the socket buffers. It suppors the chained and ring
1020  * modes.
1021  */
1022 static int init_dma_desc_rings(struct net_device *dev, gfp_t flags)
1023 {
1024 	int i;
1025 	struct stmmac_priv *priv = netdev_priv(dev);
1026 	unsigned int txsize = priv->dma_tx_size;
1027 	unsigned int rxsize = priv->dma_rx_size;
1028 	unsigned int bfsize = 0;
1029 	int ret = -ENOMEM;
1030 
1031 	if (priv->hw->mode->set_16kib_bfsize)
1032 		bfsize = priv->hw->mode->set_16kib_bfsize(dev->mtu);
1033 
1034 	if (bfsize < BUF_SIZE_16KiB)
1035 		bfsize = stmmac_set_bfsize(dev->mtu, priv->dma_buf_sz);
1036 
1037 	priv->dma_buf_sz = bfsize;
1038 
1039 	if (netif_msg_probe(priv))
1040 		pr_debug("%s: txsize %d, rxsize %d, bfsize %d\n", __func__,
1041 			 txsize, rxsize, bfsize);
1042 
1043 	if (netif_msg_probe(priv)) {
1044 		pr_debug("(%s) dma_rx_phy=0x%08x dma_tx_phy=0x%08x\n", __func__,
1045 			 (u32) priv->dma_rx_phy, (u32) priv->dma_tx_phy);
1046 
1047 		/* RX INITIALIZATION */
1048 		pr_debug("\tSKB addresses:\nskb\t\tskb data\tdma data\n");
1049 	}
1050 	for (i = 0; i < rxsize; i++) {
1051 		struct dma_desc *p;
1052 		if (priv->extend_desc)
1053 			p = &((priv->dma_erx + i)->basic);
1054 		else
1055 			p = priv->dma_rx + i;
1056 
1057 		ret = stmmac_init_rx_buffers(priv, p, i, flags);
1058 		if (ret)
1059 			goto err_init_rx_buffers;
1060 
1061 		if (netif_msg_probe(priv))
1062 			pr_debug("[%p]\t[%p]\t[%x]\n", priv->rx_skbuff[i],
1063 				 priv->rx_skbuff[i]->data,
1064 				 (unsigned int)priv->rx_skbuff_dma[i]);
1065 	}
1066 	priv->cur_rx = 0;
1067 	priv->dirty_rx = (unsigned int)(i - rxsize);
1068 	buf_sz = bfsize;
1069 
1070 	/* Setup the chained descriptor addresses */
1071 	if (priv->mode == STMMAC_CHAIN_MODE) {
1072 		if (priv->extend_desc) {
1073 			priv->hw->mode->init(priv->dma_erx, priv->dma_rx_phy,
1074 					     rxsize, 1);
1075 			priv->hw->mode->init(priv->dma_etx, priv->dma_tx_phy,
1076 					     txsize, 1);
1077 		} else {
1078 			priv->hw->mode->init(priv->dma_rx, priv->dma_rx_phy,
1079 					     rxsize, 0);
1080 			priv->hw->mode->init(priv->dma_tx, priv->dma_tx_phy,
1081 					     txsize, 0);
1082 		}
1083 	}
1084 
1085 	/* TX INITIALIZATION */
1086 	for (i = 0; i < txsize; i++) {
1087 		struct dma_desc *p;
1088 		if (priv->extend_desc)
1089 			p = &((priv->dma_etx + i)->basic);
1090 		else
1091 			p = priv->dma_tx + i;
1092 		p->des2 = 0;
1093 		priv->tx_skbuff_dma[i].buf = 0;
1094 		priv->tx_skbuff_dma[i].map_as_page = false;
1095 		priv->tx_skbuff[i] = NULL;
1096 	}
1097 
1098 	priv->dirty_tx = 0;
1099 	priv->cur_tx = 0;
1100 
1101 	stmmac_clear_descriptors(priv);
1102 
1103 	if (netif_msg_hw(priv))
1104 		stmmac_display_rings(priv);
1105 
1106 	return 0;
1107 err_init_rx_buffers:
1108 	while (--i >= 0)
1109 		stmmac_free_rx_buffers(priv, i);
1110 	return ret;
1111 }
1112 
1113 static void dma_free_rx_skbufs(struct stmmac_priv *priv)
1114 {
1115 	int i;
1116 
1117 	for (i = 0; i < priv->dma_rx_size; i++)
1118 		stmmac_free_rx_buffers(priv, i);
1119 }
1120 
1121 static void dma_free_tx_skbufs(struct stmmac_priv *priv)
1122 {
1123 	int i;
1124 
1125 	for (i = 0; i < priv->dma_tx_size; i++) {
1126 		struct dma_desc *p;
1127 
1128 		if (priv->extend_desc)
1129 			p = &((priv->dma_etx + i)->basic);
1130 		else
1131 			p = priv->dma_tx + i;
1132 
1133 		if (priv->tx_skbuff_dma[i].buf) {
1134 			if (priv->tx_skbuff_dma[i].map_as_page)
1135 				dma_unmap_page(priv->device,
1136 					       priv->tx_skbuff_dma[i].buf,
1137 					       priv->hw->desc->get_tx_len(p),
1138 					       DMA_TO_DEVICE);
1139 			else
1140 				dma_unmap_single(priv->device,
1141 						 priv->tx_skbuff_dma[i].buf,
1142 						 priv->hw->desc->get_tx_len(p),
1143 						 DMA_TO_DEVICE);
1144 		}
1145 
1146 		if (priv->tx_skbuff[i] != NULL) {
1147 			dev_kfree_skb_any(priv->tx_skbuff[i]);
1148 			priv->tx_skbuff[i] = NULL;
1149 			priv->tx_skbuff_dma[i].buf = 0;
1150 			priv->tx_skbuff_dma[i].map_as_page = false;
1151 		}
1152 	}
1153 }
1154 
1155 /**
1156  * alloc_dma_desc_resources - alloc TX/RX resources.
1157  * @priv: private structure
1158  * Description: according to which descriptor can be used (extend or basic)
1159  * this function allocates the resources for TX and RX paths. In case of
1160  * reception, for example, it pre-allocated the RX socket buffer in order to
1161  * allow zero-copy mechanism.
1162  */
1163 static int alloc_dma_desc_resources(struct stmmac_priv *priv)
1164 {
1165 	unsigned int txsize = priv->dma_tx_size;
1166 	unsigned int rxsize = priv->dma_rx_size;
1167 	int ret = -ENOMEM;
1168 
1169 	priv->rx_skbuff_dma = kmalloc_array(rxsize, sizeof(dma_addr_t),
1170 					    GFP_KERNEL);
1171 	if (!priv->rx_skbuff_dma)
1172 		return -ENOMEM;
1173 
1174 	priv->rx_skbuff = kmalloc_array(rxsize, sizeof(struct sk_buff *),
1175 					GFP_KERNEL);
1176 	if (!priv->rx_skbuff)
1177 		goto err_rx_skbuff;
1178 
1179 	priv->tx_skbuff_dma = kmalloc_array(txsize,
1180 					    sizeof(*priv->tx_skbuff_dma),
1181 					    GFP_KERNEL);
1182 	if (!priv->tx_skbuff_dma)
1183 		goto err_tx_skbuff_dma;
1184 
1185 	priv->tx_skbuff = kmalloc_array(txsize, sizeof(struct sk_buff *),
1186 					GFP_KERNEL);
1187 	if (!priv->tx_skbuff)
1188 		goto err_tx_skbuff;
1189 
1190 	if (priv->extend_desc) {
1191 		priv->dma_erx = dma_alloc_coherent(priv->device, rxsize *
1192 						   sizeof(struct
1193 							  dma_extended_desc),
1194 						   &priv->dma_rx_phy,
1195 						   GFP_KERNEL);
1196 		if (!priv->dma_erx)
1197 			goto err_dma;
1198 
1199 		priv->dma_etx = dma_alloc_coherent(priv->device, txsize *
1200 						   sizeof(struct
1201 							  dma_extended_desc),
1202 						   &priv->dma_tx_phy,
1203 						   GFP_KERNEL);
1204 		if (!priv->dma_etx) {
1205 			dma_free_coherent(priv->device, priv->dma_rx_size *
1206 					sizeof(struct dma_extended_desc),
1207 					priv->dma_erx, priv->dma_rx_phy);
1208 			goto err_dma;
1209 		}
1210 	} else {
1211 		priv->dma_rx = dma_alloc_coherent(priv->device, rxsize *
1212 						  sizeof(struct dma_desc),
1213 						  &priv->dma_rx_phy,
1214 						  GFP_KERNEL);
1215 		if (!priv->dma_rx)
1216 			goto err_dma;
1217 
1218 		priv->dma_tx = dma_alloc_coherent(priv->device, txsize *
1219 						  sizeof(struct dma_desc),
1220 						  &priv->dma_tx_phy,
1221 						  GFP_KERNEL);
1222 		if (!priv->dma_tx) {
1223 			dma_free_coherent(priv->device, priv->dma_rx_size *
1224 					sizeof(struct dma_desc),
1225 					priv->dma_rx, priv->dma_rx_phy);
1226 			goto err_dma;
1227 		}
1228 	}
1229 
1230 	return 0;
1231 
1232 err_dma:
1233 	kfree(priv->tx_skbuff);
1234 err_tx_skbuff:
1235 	kfree(priv->tx_skbuff_dma);
1236 err_tx_skbuff_dma:
1237 	kfree(priv->rx_skbuff);
1238 err_rx_skbuff:
1239 	kfree(priv->rx_skbuff_dma);
1240 	return ret;
1241 }
1242 
1243 static void free_dma_desc_resources(struct stmmac_priv *priv)
1244 {
1245 	/* Release the DMA TX/RX socket buffers */
1246 	dma_free_rx_skbufs(priv);
1247 	dma_free_tx_skbufs(priv);
1248 
1249 	/* Free DMA regions of consistent memory previously allocated */
1250 	if (!priv->extend_desc) {
1251 		dma_free_coherent(priv->device,
1252 				  priv->dma_tx_size * sizeof(struct dma_desc),
1253 				  priv->dma_tx, priv->dma_tx_phy);
1254 		dma_free_coherent(priv->device,
1255 				  priv->dma_rx_size * sizeof(struct dma_desc),
1256 				  priv->dma_rx, priv->dma_rx_phy);
1257 	} else {
1258 		dma_free_coherent(priv->device, priv->dma_tx_size *
1259 				  sizeof(struct dma_extended_desc),
1260 				  priv->dma_etx, priv->dma_tx_phy);
1261 		dma_free_coherent(priv->device, priv->dma_rx_size *
1262 				  sizeof(struct dma_extended_desc),
1263 				  priv->dma_erx, priv->dma_rx_phy);
1264 	}
1265 	kfree(priv->rx_skbuff_dma);
1266 	kfree(priv->rx_skbuff);
1267 	kfree(priv->tx_skbuff_dma);
1268 	kfree(priv->tx_skbuff);
1269 }
1270 
1271 /**
1272  *  stmmac_dma_operation_mode - HW DMA operation mode
1273  *  @priv: driver private structure
1274  *  Description: it is used for configuring the DMA operation mode register in
1275  *  order to program the tx/rx DMA thresholds or Store-And-Forward mode.
1276  */
1277 static void stmmac_dma_operation_mode(struct stmmac_priv *priv)
1278 {
1279 	if (priv->plat->force_thresh_dma_mode)
1280 		priv->hw->dma->dma_mode(priv->ioaddr, tc, tc);
1281 	else if (priv->plat->force_sf_dma_mode || priv->plat->tx_coe) {
1282 		/*
1283 		 * In case of GMAC, SF mode can be enabled
1284 		 * to perform the TX COE in HW. This depends on:
1285 		 * 1) TX COE if actually supported
1286 		 * 2) There is no bugged Jumbo frame support
1287 		 *    that needs to not insert csum in the TDES.
1288 		 */
1289 		priv->hw->dma->dma_mode(priv->ioaddr, SF_DMA_MODE, SF_DMA_MODE);
1290 		tc = SF_DMA_MODE;
1291 	} else
1292 		priv->hw->dma->dma_mode(priv->ioaddr, tc, SF_DMA_MODE);
1293 }
1294 
1295 /**
1296  * stmmac_tx_clean - to manage the transmission completion
1297  * @priv: driver private structure
1298  * Description: it reclaims the transmit resources after transmission completes.
1299  */
1300 static void stmmac_tx_clean(struct stmmac_priv *priv)
1301 {
1302 	unsigned int txsize = priv->dma_tx_size;
1303 
1304 	spin_lock(&priv->tx_lock);
1305 
1306 	priv->xstats.tx_clean++;
1307 
1308 	while (priv->dirty_tx != priv->cur_tx) {
1309 		int last;
1310 		unsigned int entry = priv->dirty_tx % txsize;
1311 		struct sk_buff *skb = priv->tx_skbuff[entry];
1312 		struct dma_desc *p;
1313 
1314 		if (priv->extend_desc)
1315 			p = (struct dma_desc *)(priv->dma_etx + entry);
1316 		else
1317 			p = priv->dma_tx + entry;
1318 
1319 		/* Check if the descriptor is owned by the DMA. */
1320 		if (priv->hw->desc->get_tx_owner(p))
1321 			break;
1322 
1323 		/* Verify tx error by looking at the last segment. */
1324 		last = priv->hw->desc->get_tx_ls(p);
1325 		if (likely(last)) {
1326 			int tx_error =
1327 			    priv->hw->desc->tx_status(&priv->dev->stats,
1328 						      &priv->xstats, p,
1329 						      priv->ioaddr);
1330 			if (likely(tx_error == 0)) {
1331 				priv->dev->stats.tx_packets++;
1332 				priv->xstats.tx_pkt_n++;
1333 			} else
1334 				priv->dev->stats.tx_errors++;
1335 
1336 			stmmac_get_tx_hwtstamp(priv, entry, skb);
1337 		}
1338 		if (netif_msg_tx_done(priv))
1339 			pr_debug("%s: curr %d, dirty %d\n", __func__,
1340 				 priv->cur_tx, priv->dirty_tx);
1341 
1342 		if (likely(priv->tx_skbuff_dma[entry].buf)) {
1343 			if (priv->tx_skbuff_dma[entry].map_as_page)
1344 				dma_unmap_page(priv->device,
1345 					       priv->tx_skbuff_dma[entry].buf,
1346 					       priv->hw->desc->get_tx_len(p),
1347 					       DMA_TO_DEVICE);
1348 			else
1349 				dma_unmap_single(priv->device,
1350 						 priv->tx_skbuff_dma[entry].buf,
1351 						 priv->hw->desc->get_tx_len(p),
1352 						 DMA_TO_DEVICE);
1353 			priv->tx_skbuff_dma[entry].buf = 0;
1354 			priv->tx_skbuff_dma[entry].map_as_page = false;
1355 		}
1356 		priv->hw->mode->clean_desc3(priv, p);
1357 
1358 		if (likely(skb != NULL)) {
1359 			dev_consume_skb_any(skb);
1360 			priv->tx_skbuff[entry] = NULL;
1361 		}
1362 
1363 		priv->hw->desc->release_tx_desc(p, priv->mode);
1364 
1365 		priv->dirty_tx++;
1366 	}
1367 	if (unlikely(netif_queue_stopped(priv->dev) &&
1368 		     stmmac_tx_avail(priv) > STMMAC_TX_THRESH(priv))) {
1369 		netif_tx_lock(priv->dev);
1370 		if (netif_queue_stopped(priv->dev) &&
1371 		    stmmac_tx_avail(priv) > STMMAC_TX_THRESH(priv)) {
1372 			if (netif_msg_tx_done(priv))
1373 				pr_debug("%s: restart transmit\n", __func__);
1374 			netif_wake_queue(priv->dev);
1375 		}
1376 		netif_tx_unlock(priv->dev);
1377 	}
1378 
1379 	if ((priv->eee_enabled) && (!priv->tx_path_in_lpi_mode)) {
1380 		stmmac_enable_eee_mode(priv);
1381 		mod_timer(&priv->eee_ctrl_timer, STMMAC_LPI_T(eee_timer));
1382 	}
1383 	spin_unlock(&priv->tx_lock);
1384 }
1385 
1386 static inline void stmmac_enable_dma_irq(struct stmmac_priv *priv)
1387 {
1388 	priv->hw->dma->enable_dma_irq(priv->ioaddr);
1389 }
1390 
1391 static inline void stmmac_disable_dma_irq(struct stmmac_priv *priv)
1392 {
1393 	priv->hw->dma->disable_dma_irq(priv->ioaddr);
1394 }
1395 
1396 /**
1397  * stmmac_tx_err - to manage the tx error
1398  * @priv: driver private structure
1399  * Description: it cleans the descriptors and restarts the transmission
1400  * in case of transmission errors.
1401  */
1402 static void stmmac_tx_err(struct stmmac_priv *priv)
1403 {
1404 	int i;
1405 	int txsize = priv->dma_tx_size;
1406 	netif_stop_queue(priv->dev);
1407 
1408 	priv->hw->dma->stop_tx(priv->ioaddr);
1409 	dma_free_tx_skbufs(priv);
1410 	for (i = 0; i < txsize; i++)
1411 		if (priv->extend_desc)
1412 			priv->hw->desc->init_tx_desc(&priv->dma_etx[i].basic,
1413 						     priv->mode,
1414 						     (i == txsize - 1));
1415 		else
1416 			priv->hw->desc->init_tx_desc(&priv->dma_tx[i],
1417 						     priv->mode,
1418 						     (i == txsize - 1));
1419 	priv->dirty_tx = 0;
1420 	priv->cur_tx = 0;
1421 	priv->hw->dma->start_tx(priv->ioaddr);
1422 
1423 	priv->dev->stats.tx_errors++;
1424 	netif_wake_queue(priv->dev);
1425 }
1426 
1427 /**
1428  * stmmac_dma_interrupt - DMA ISR
1429  * @priv: driver private structure
1430  * Description: this is the DMA ISR. It is called by the main ISR.
1431  * It calls the dwmac dma routine and schedule poll method in case of some
1432  * work can be done.
1433  */
1434 static void stmmac_dma_interrupt(struct stmmac_priv *priv)
1435 {
1436 	int status;
1437 
1438 	status = priv->hw->dma->dma_interrupt(priv->ioaddr, &priv->xstats);
1439 	if (likely((status & handle_rx)) || (status & handle_tx)) {
1440 		if (likely(napi_schedule_prep(&priv->napi))) {
1441 			stmmac_disable_dma_irq(priv);
1442 			__napi_schedule(&priv->napi);
1443 		}
1444 	}
1445 	if (unlikely(status & tx_hard_error_bump_tc)) {
1446 		/* Try to bump up the dma threshold on this failure */
1447 		if (unlikely(tc != SF_DMA_MODE) && (tc <= 256)) {
1448 			tc += 64;
1449 			priv->hw->dma->dma_mode(priv->ioaddr, tc, SF_DMA_MODE);
1450 			priv->xstats.threshold = tc;
1451 		}
1452 	} else if (unlikely(status == tx_hard_error))
1453 		stmmac_tx_err(priv);
1454 }
1455 
1456 /**
1457  * stmmac_mmc_setup: setup the Mac Management Counters (MMC)
1458  * @priv: driver private structure
1459  * Description: this masks the MMC irq, in fact, the counters are managed in SW.
1460  */
1461 static void stmmac_mmc_setup(struct stmmac_priv *priv)
1462 {
1463 	unsigned int mode = MMC_CNTRL_RESET_ON_READ | MMC_CNTRL_COUNTER_RESET |
1464 	    MMC_CNTRL_PRESET | MMC_CNTRL_FULL_HALF_PRESET;
1465 
1466 	dwmac_mmc_intr_all_mask(priv->ioaddr);
1467 
1468 	if (priv->dma_cap.rmon) {
1469 		dwmac_mmc_ctrl(priv->ioaddr, mode);
1470 		memset(&priv->mmc, 0, sizeof(struct stmmac_counters));
1471 	} else
1472 		pr_info(" No MAC Management Counters available\n");
1473 }
1474 
1475 /**
1476  * stmmac_get_synopsys_id - return the SYINID.
1477  * @priv: driver private structure
1478  * Description: this simple function is to decode and return the SYINID
1479  * starting from the HW core register.
1480  */
1481 static u32 stmmac_get_synopsys_id(struct stmmac_priv *priv)
1482 {
1483 	u32 hwid = priv->hw->synopsys_uid;
1484 
1485 	/* Check Synopsys Id (not available on old chips) */
1486 	if (likely(hwid)) {
1487 		u32 uid = ((hwid & 0x0000ff00) >> 8);
1488 		u32 synid = (hwid & 0x000000ff);
1489 
1490 		pr_info("stmmac - user ID: 0x%x, Synopsys ID: 0x%x\n",
1491 			uid, synid);
1492 
1493 		return synid;
1494 	}
1495 	return 0;
1496 }
1497 
1498 /**
1499  * stmmac_selec_desc_mode - to select among: normal/alternate/extend descriptors
1500  * @priv: driver private structure
1501  * Description: select the Enhanced/Alternate or Normal descriptors.
1502  * In case of Enhanced/Alternate, it checks if the extended descriptors are
1503  * supported by the HW capability register.
1504  */
1505 static void stmmac_selec_desc_mode(struct stmmac_priv *priv)
1506 {
1507 	if (priv->plat->enh_desc) {
1508 		pr_info(" Enhanced/Alternate descriptors\n");
1509 
1510 		/* GMAC older than 3.50 has no extended descriptors */
1511 		if (priv->synopsys_id >= DWMAC_CORE_3_50) {
1512 			pr_info("\tEnabled extended descriptors\n");
1513 			priv->extend_desc = 1;
1514 		} else
1515 			pr_warn("Extended descriptors not supported\n");
1516 
1517 		priv->hw->desc = &enh_desc_ops;
1518 	} else {
1519 		pr_info(" Normal descriptors\n");
1520 		priv->hw->desc = &ndesc_ops;
1521 	}
1522 }
1523 
1524 /**
1525  * stmmac_get_hw_features - get MAC capabilities from the HW cap. register.
1526  * @priv: driver private structure
1527  * Description:
1528  *  new GMAC chip generations have a new register to indicate the
1529  *  presence of the optional feature/functions.
1530  *  This can be also used to override the value passed through the
1531  *  platform and necessary for old MAC10/100 and GMAC chips.
1532  */
1533 static int stmmac_get_hw_features(struct stmmac_priv *priv)
1534 {
1535 	u32 hw_cap = 0;
1536 
1537 	if (priv->hw->dma->get_hw_feature) {
1538 		hw_cap = priv->hw->dma->get_hw_feature(priv->ioaddr);
1539 
1540 		priv->dma_cap.mbps_10_100 = (hw_cap & DMA_HW_FEAT_MIISEL);
1541 		priv->dma_cap.mbps_1000 = (hw_cap & DMA_HW_FEAT_GMIISEL) >> 1;
1542 		priv->dma_cap.half_duplex = (hw_cap & DMA_HW_FEAT_HDSEL) >> 2;
1543 		priv->dma_cap.hash_filter = (hw_cap & DMA_HW_FEAT_HASHSEL) >> 4;
1544 		priv->dma_cap.multi_addr = (hw_cap & DMA_HW_FEAT_ADDMAC) >> 5;
1545 		priv->dma_cap.pcs = (hw_cap & DMA_HW_FEAT_PCSSEL) >> 6;
1546 		priv->dma_cap.sma_mdio = (hw_cap & DMA_HW_FEAT_SMASEL) >> 8;
1547 		priv->dma_cap.pmt_remote_wake_up =
1548 		    (hw_cap & DMA_HW_FEAT_RWKSEL) >> 9;
1549 		priv->dma_cap.pmt_magic_frame =
1550 		    (hw_cap & DMA_HW_FEAT_MGKSEL) >> 10;
1551 		/* MMC */
1552 		priv->dma_cap.rmon = (hw_cap & DMA_HW_FEAT_MMCSEL) >> 11;
1553 		/* IEEE 1588-2002 */
1554 		priv->dma_cap.time_stamp =
1555 		    (hw_cap & DMA_HW_FEAT_TSVER1SEL) >> 12;
1556 		/* IEEE 1588-2008 */
1557 		priv->dma_cap.atime_stamp =
1558 		    (hw_cap & DMA_HW_FEAT_TSVER2SEL) >> 13;
1559 		/* 802.3az - Energy-Efficient Ethernet (EEE) */
1560 		priv->dma_cap.eee = (hw_cap & DMA_HW_FEAT_EEESEL) >> 14;
1561 		priv->dma_cap.av = (hw_cap & DMA_HW_FEAT_AVSEL) >> 15;
1562 		/* TX and RX csum */
1563 		priv->dma_cap.tx_coe = (hw_cap & DMA_HW_FEAT_TXCOESEL) >> 16;
1564 		priv->dma_cap.rx_coe_type1 =
1565 		    (hw_cap & DMA_HW_FEAT_RXTYP1COE) >> 17;
1566 		priv->dma_cap.rx_coe_type2 =
1567 		    (hw_cap & DMA_HW_FEAT_RXTYP2COE) >> 18;
1568 		priv->dma_cap.rxfifo_over_2048 =
1569 		    (hw_cap & DMA_HW_FEAT_RXFIFOSIZE) >> 19;
1570 		/* TX and RX number of channels */
1571 		priv->dma_cap.number_rx_channel =
1572 		    (hw_cap & DMA_HW_FEAT_RXCHCNT) >> 20;
1573 		priv->dma_cap.number_tx_channel =
1574 		    (hw_cap & DMA_HW_FEAT_TXCHCNT) >> 22;
1575 		/* Alternate (enhanced) DESC mode */
1576 		priv->dma_cap.enh_desc = (hw_cap & DMA_HW_FEAT_ENHDESSEL) >> 24;
1577 	}
1578 
1579 	return hw_cap;
1580 }
1581 
1582 /**
1583  * stmmac_check_ether_addr - check if the MAC addr is valid
1584  * @priv: driver private structure
1585  * Description:
1586  * it is to verify if the MAC address is valid, in case of failures it
1587  * generates a random MAC address
1588  */
1589 static void stmmac_check_ether_addr(struct stmmac_priv *priv)
1590 {
1591 	if (!is_valid_ether_addr(priv->dev->dev_addr)) {
1592 		priv->hw->mac->get_umac_addr(priv->hw,
1593 					     priv->dev->dev_addr, 0);
1594 		if (!is_valid_ether_addr(priv->dev->dev_addr))
1595 			eth_hw_addr_random(priv->dev);
1596 		pr_info("%s: device MAC address %pM\n", priv->dev->name,
1597 			priv->dev->dev_addr);
1598 	}
1599 }
1600 
1601 /**
1602  * stmmac_init_dma_engine - DMA init.
1603  * @priv: driver private structure
1604  * Description:
1605  * It inits the DMA invoking the specific MAC/GMAC callback.
1606  * Some DMA parameters can be passed from the platform;
1607  * in case of these are not passed a default is kept for the MAC or GMAC.
1608  */
1609 static int stmmac_init_dma_engine(struct stmmac_priv *priv)
1610 {
1611 	int pbl = DEFAULT_DMA_PBL, fixed_burst = 0, burst_len = 0;
1612 	int mixed_burst = 0;
1613 	int atds = 0;
1614 
1615 	if (priv->plat->dma_cfg) {
1616 		pbl = priv->plat->dma_cfg->pbl;
1617 		fixed_burst = priv->plat->dma_cfg->fixed_burst;
1618 		mixed_burst = priv->plat->dma_cfg->mixed_burst;
1619 		burst_len = priv->plat->dma_cfg->burst_len;
1620 	}
1621 
1622 	if (priv->extend_desc && (priv->mode == STMMAC_RING_MODE))
1623 		atds = 1;
1624 
1625 	return priv->hw->dma->init(priv->ioaddr, pbl, fixed_burst, mixed_burst,
1626 				   burst_len, priv->dma_tx_phy,
1627 				   priv->dma_rx_phy, atds);
1628 }
1629 
1630 /**
1631  * stmmac_tx_timer - mitigation sw timer for tx.
1632  * @data: data pointer
1633  * Description:
1634  * This is the timer handler to directly invoke the stmmac_tx_clean.
1635  */
1636 static void stmmac_tx_timer(unsigned long data)
1637 {
1638 	struct stmmac_priv *priv = (struct stmmac_priv *)data;
1639 
1640 	stmmac_tx_clean(priv);
1641 }
1642 
1643 /**
1644  * stmmac_init_tx_coalesce - init tx mitigation options.
1645  * @priv: driver private structure
1646  * Description:
1647  * This inits the transmit coalesce parameters: i.e. timer rate,
1648  * timer handler and default threshold used for enabling the
1649  * interrupt on completion bit.
1650  */
1651 static void stmmac_init_tx_coalesce(struct stmmac_priv *priv)
1652 {
1653 	priv->tx_coal_frames = STMMAC_TX_FRAMES;
1654 	priv->tx_coal_timer = STMMAC_COAL_TX_TIMER;
1655 	init_timer(&priv->txtimer);
1656 	priv->txtimer.expires = STMMAC_COAL_TIMER(priv->tx_coal_timer);
1657 	priv->txtimer.data = (unsigned long)priv;
1658 	priv->txtimer.function = stmmac_tx_timer;
1659 	add_timer(&priv->txtimer);
1660 }
1661 
1662 /**
1663  * stmmac_hw_setup - setup mac in a usable state.
1664  *  @dev : pointer to the device structure.
1665  *  Description:
1666  *  this is the main function to setup the HW in a usable state because the
1667  *  dma engine is reset, the core registers are configured (e.g. AXI,
1668  *  Checksum features, timers). The DMA is ready to start receiving and
1669  *  transmitting.
1670  *  Return value:
1671  *  0 on success and an appropriate (-)ve integer as defined in errno.h
1672  *  file on failure.
1673  */
1674 static int stmmac_hw_setup(struct net_device *dev, bool init_ptp)
1675 {
1676 	struct stmmac_priv *priv = netdev_priv(dev);
1677 	int ret;
1678 
1679 	/* DMA initialization and SW reset */
1680 	ret = stmmac_init_dma_engine(priv);
1681 	if (ret < 0) {
1682 		pr_err("%s: DMA engine initialization failed\n", __func__);
1683 		return ret;
1684 	}
1685 
1686 	/* Copy the MAC addr into the HW  */
1687 	priv->hw->mac->set_umac_addr(priv->hw, dev->dev_addr, 0);
1688 
1689 	/* If required, perform hw setup of the bus. */
1690 	if (priv->plat->bus_setup)
1691 		priv->plat->bus_setup(priv->ioaddr);
1692 
1693 	/* Initialize the MAC Core */
1694 	priv->hw->mac->core_init(priv->hw, dev->mtu);
1695 
1696 	ret = priv->hw->mac->rx_ipc(priv->hw);
1697 	if (!ret) {
1698 		pr_warn(" RX IPC Checksum Offload disabled\n");
1699 		priv->plat->rx_coe = STMMAC_RX_COE_NONE;
1700 		priv->hw->rx_csum = 0;
1701 	}
1702 
1703 	/* Enable the MAC Rx/Tx */
1704 	stmmac_set_mac(priv->ioaddr, true);
1705 
1706 	/* Set the HW DMA mode and the COE */
1707 	stmmac_dma_operation_mode(priv);
1708 
1709 	stmmac_mmc_setup(priv);
1710 
1711 	if (init_ptp) {
1712 		ret = stmmac_init_ptp(priv);
1713 		if (ret && ret != -EOPNOTSUPP)
1714 			pr_warn("%s: failed PTP initialisation\n", __func__);
1715 	}
1716 
1717 #ifdef CONFIG_DEBUG_FS
1718 	ret = stmmac_init_fs(dev);
1719 	if (ret < 0)
1720 		pr_warn("%s: failed debugFS registration\n", __func__);
1721 #endif
1722 	/* Start the ball rolling... */
1723 	pr_debug("%s: DMA RX/TX processes started...\n", dev->name);
1724 	priv->hw->dma->start_tx(priv->ioaddr);
1725 	priv->hw->dma->start_rx(priv->ioaddr);
1726 
1727 	/* Dump DMA/MAC registers */
1728 	if (netif_msg_hw(priv)) {
1729 		priv->hw->mac->dump_regs(priv->hw);
1730 		priv->hw->dma->dump_regs(priv->ioaddr);
1731 	}
1732 	priv->tx_lpi_timer = STMMAC_DEFAULT_TWT_LS;
1733 
1734 	if ((priv->use_riwt) && (priv->hw->dma->rx_watchdog)) {
1735 		priv->rx_riwt = MAX_DMA_RIWT;
1736 		priv->hw->dma->rx_watchdog(priv->ioaddr, MAX_DMA_RIWT);
1737 	}
1738 
1739 	if (priv->pcs && priv->hw->mac->ctrl_ane)
1740 		priv->hw->mac->ctrl_ane(priv->hw, 0);
1741 
1742 	return 0;
1743 }
1744 
1745 /**
1746  *  stmmac_open - open entry point of the driver
1747  *  @dev : pointer to the device structure.
1748  *  Description:
1749  *  This function is the open entry point of the driver.
1750  *  Return value:
1751  *  0 on success and an appropriate (-)ve integer as defined in errno.h
1752  *  file on failure.
1753  */
1754 static int stmmac_open(struct net_device *dev)
1755 {
1756 	struct stmmac_priv *priv = netdev_priv(dev);
1757 	int ret;
1758 
1759 	stmmac_check_ether_addr(priv);
1760 
1761 	if (priv->pcs != STMMAC_PCS_RGMII && priv->pcs != STMMAC_PCS_TBI &&
1762 	    priv->pcs != STMMAC_PCS_RTBI) {
1763 		ret = stmmac_init_phy(dev);
1764 		if (ret) {
1765 			pr_err("%s: Cannot attach to PHY (error: %d)\n",
1766 			       __func__, ret);
1767 			return ret;
1768 		}
1769 	}
1770 
1771 	/* Extra statistics */
1772 	memset(&priv->xstats, 0, sizeof(struct stmmac_extra_stats));
1773 	priv->xstats.threshold = tc;
1774 
1775 	/* Create and initialize the TX/RX descriptors chains. */
1776 	priv->dma_tx_size = STMMAC_ALIGN(dma_txsize);
1777 	priv->dma_rx_size = STMMAC_ALIGN(dma_rxsize);
1778 	priv->dma_buf_sz = STMMAC_ALIGN(buf_sz);
1779 
1780 	ret = alloc_dma_desc_resources(priv);
1781 	if (ret < 0) {
1782 		pr_err("%s: DMA descriptors allocation failed\n", __func__);
1783 		goto dma_desc_error;
1784 	}
1785 
1786 	ret = init_dma_desc_rings(dev, GFP_KERNEL);
1787 	if (ret < 0) {
1788 		pr_err("%s: DMA descriptors initialization failed\n", __func__);
1789 		goto init_error;
1790 	}
1791 
1792 	ret = stmmac_hw_setup(dev, true);
1793 	if (ret < 0) {
1794 		pr_err("%s: Hw setup failed\n", __func__);
1795 		goto init_error;
1796 	}
1797 
1798 	stmmac_init_tx_coalesce(priv);
1799 
1800 	if (priv->phydev)
1801 		phy_start(priv->phydev);
1802 
1803 	/* Request the IRQ lines */
1804 	ret = request_irq(dev->irq, stmmac_interrupt,
1805 			  IRQF_SHARED, dev->name, dev);
1806 	if (unlikely(ret < 0)) {
1807 		pr_err("%s: ERROR: allocating the IRQ %d (error: %d)\n",
1808 		       __func__, dev->irq, ret);
1809 		goto init_error;
1810 	}
1811 
1812 	/* Request the Wake IRQ in case of another line is used for WoL */
1813 	if (priv->wol_irq != dev->irq) {
1814 		ret = request_irq(priv->wol_irq, stmmac_interrupt,
1815 				  IRQF_SHARED, dev->name, dev);
1816 		if (unlikely(ret < 0)) {
1817 			pr_err("%s: ERROR: allocating the WoL IRQ %d (%d)\n",
1818 			       __func__, priv->wol_irq, ret);
1819 			goto wolirq_error;
1820 		}
1821 	}
1822 
1823 	/* Request the IRQ lines */
1824 	if (priv->lpi_irq > 0) {
1825 		ret = request_irq(priv->lpi_irq, stmmac_interrupt, IRQF_SHARED,
1826 				  dev->name, dev);
1827 		if (unlikely(ret < 0)) {
1828 			pr_err("%s: ERROR: allocating the LPI IRQ %d (%d)\n",
1829 			       __func__, priv->lpi_irq, ret);
1830 			goto lpiirq_error;
1831 		}
1832 	}
1833 
1834 	napi_enable(&priv->napi);
1835 	netif_start_queue(dev);
1836 
1837 	return 0;
1838 
1839 lpiirq_error:
1840 	if (priv->wol_irq != dev->irq)
1841 		free_irq(priv->wol_irq, dev);
1842 wolirq_error:
1843 	free_irq(dev->irq, dev);
1844 
1845 init_error:
1846 	free_dma_desc_resources(priv);
1847 dma_desc_error:
1848 	if (priv->phydev)
1849 		phy_disconnect(priv->phydev);
1850 
1851 	return ret;
1852 }
1853 
1854 /**
1855  *  stmmac_release - close entry point of the driver
1856  *  @dev : device pointer.
1857  *  Description:
1858  *  This is the stop entry point of the driver.
1859  */
1860 static int stmmac_release(struct net_device *dev)
1861 {
1862 	struct stmmac_priv *priv = netdev_priv(dev);
1863 
1864 	if (priv->eee_enabled)
1865 		del_timer_sync(&priv->eee_ctrl_timer);
1866 
1867 	/* Stop and disconnect the PHY */
1868 	if (priv->phydev) {
1869 		phy_stop(priv->phydev);
1870 		phy_disconnect(priv->phydev);
1871 		priv->phydev = NULL;
1872 	}
1873 
1874 	netif_stop_queue(dev);
1875 
1876 	napi_disable(&priv->napi);
1877 
1878 	del_timer_sync(&priv->txtimer);
1879 
1880 	/* Free the IRQ lines */
1881 	free_irq(dev->irq, dev);
1882 	if (priv->wol_irq != dev->irq)
1883 		free_irq(priv->wol_irq, dev);
1884 	if (priv->lpi_irq > 0)
1885 		free_irq(priv->lpi_irq, dev);
1886 
1887 	/* Stop TX/RX DMA and clear the descriptors */
1888 	priv->hw->dma->stop_tx(priv->ioaddr);
1889 	priv->hw->dma->stop_rx(priv->ioaddr);
1890 
1891 	/* Release and free the Rx/Tx resources */
1892 	free_dma_desc_resources(priv);
1893 
1894 	/* Disable the MAC Rx/Tx */
1895 	stmmac_set_mac(priv->ioaddr, false);
1896 
1897 	netif_carrier_off(dev);
1898 
1899 #ifdef CONFIG_DEBUG_FS
1900 	stmmac_exit_fs();
1901 #endif
1902 
1903 	stmmac_release_ptp(priv);
1904 
1905 	return 0;
1906 }
1907 
1908 /**
1909  *  stmmac_xmit - Tx entry point of the driver
1910  *  @skb : the socket buffer
1911  *  @dev : device pointer
1912  *  Description : this is the tx entry point of the driver.
1913  *  It programs the chain or the ring and supports oversized frames
1914  *  and SG feature.
1915  */
1916 static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
1917 {
1918 	struct stmmac_priv *priv = netdev_priv(dev);
1919 	unsigned int txsize = priv->dma_tx_size;
1920 	unsigned int entry;
1921 	int i, csum_insertion = 0, is_jumbo = 0;
1922 	int nfrags = skb_shinfo(skb)->nr_frags;
1923 	struct dma_desc *desc, *first;
1924 	unsigned int nopaged_len = skb_headlen(skb);
1925 	unsigned int enh_desc = priv->plat->enh_desc;
1926 
1927 	spin_lock(&priv->tx_lock);
1928 
1929 	if (unlikely(stmmac_tx_avail(priv) < nfrags + 1)) {
1930 		spin_unlock(&priv->tx_lock);
1931 		if (!netif_queue_stopped(dev)) {
1932 			netif_stop_queue(dev);
1933 			/* This is a hard error, log it. */
1934 			pr_err("%s: Tx Ring full when queue awake\n", __func__);
1935 		}
1936 		return NETDEV_TX_BUSY;
1937 	}
1938 
1939 	if (priv->tx_path_in_lpi_mode)
1940 		stmmac_disable_eee_mode(priv);
1941 
1942 	entry = priv->cur_tx % txsize;
1943 
1944 	csum_insertion = (skb->ip_summed == CHECKSUM_PARTIAL);
1945 
1946 	if (priv->extend_desc)
1947 		desc = (struct dma_desc *)(priv->dma_etx + entry);
1948 	else
1949 		desc = priv->dma_tx + entry;
1950 
1951 	first = desc;
1952 
1953 	/* To program the descriptors according to the size of the frame */
1954 	if (enh_desc)
1955 		is_jumbo = priv->hw->mode->is_jumbo_frm(skb->len, enh_desc);
1956 
1957 	if (likely(!is_jumbo)) {
1958 		desc->des2 = dma_map_single(priv->device, skb->data,
1959 					    nopaged_len, DMA_TO_DEVICE);
1960 		if (dma_mapping_error(priv->device, desc->des2))
1961 			goto dma_map_err;
1962 		priv->tx_skbuff_dma[entry].buf = desc->des2;
1963 		priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len,
1964 						csum_insertion, priv->mode);
1965 	} else {
1966 		desc = first;
1967 		entry = priv->hw->mode->jumbo_frm(priv, skb, csum_insertion);
1968 		if (unlikely(entry < 0))
1969 			goto dma_map_err;
1970 	}
1971 
1972 	for (i = 0; i < nfrags; i++) {
1973 		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1974 		int len = skb_frag_size(frag);
1975 
1976 		priv->tx_skbuff[entry] = NULL;
1977 		entry = (++priv->cur_tx) % txsize;
1978 		if (priv->extend_desc)
1979 			desc = (struct dma_desc *)(priv->dma_etx + entry);
1980 		else
1981 			desc = priv->dma_tx + entry;
1982 
1983 		desc->des2 = skb_frag_dma_map(priv->device, frag, 0, len,
1984 					      DMA_TO_DEVICE);
1985 		if (dma_mapping_error(priv->device, desc->des2))
1986 			goto dma_map_err; /* should reuse desc w/o issues */
1987 
1988 		priv->tx_skbuff_dma[entry].buf = desc->des2;
1989 		priv->tx_skbuff_dma[entry].map_as_page = true;
1990 		priv->hw->desc->prepare_tx_desc(desc, 0, len, csum_insertion,
1991 						priv->mode);
1992 		wmb();
1993 		priv->hw->desc->set_tx_owner(desc);
1994 		wmb();
1995 	}
1996 
1997 	priv->tx_skbuff[entry] = skb;
1998 
1999 	/* Finalize the latest segment. */
2000 	priv->hw->desc->close_tx_desc(desc);
2001 
2002 	wmb();
2003 	/* According to the coalesce parameter the IC bit for the latest
2004 	 * segment could be reset and the timer re-started to invoke the
2005 	 * stmmac_tx function. This approach takes care about the fragments.
2006 	 */
2007 	priv->tx_count_frames += nfrags + 1;
2008 	if (priv->tx_coal_frames > priv->tx_count_frames) {
2009 		priv->hw->desc->clear_tx_ic(desc);
2010 		priv->xstats.tx_reset_ic_bit++;
2011 		mod_timer(&priv->txtimer,
2012 			  STMMAC_COAL_TIMER(priv->tx_coal_timer));
2013 	} else
2014 		priv->tx_count_frames = 0;
2015 
2016 	/* To avoid raise condition */
2017 	priv->hw->desc->set_tx_owner(first);
2018 	wmb();
2019 
2020 	priv->cur_tx++;
2021 
2022 	if (netif_msg_pktdata(priv)) {
2023 		pr_debug("%s: curr %d dirty=%d entry=%d, first=%p, nfrags=%d",
2024 			__func__, (priv->cur_tx % txsize),
2025 			(priv->dirty_tx % txsize), entry, first, nfrags);
2026 
2027 		if (priv->extend_desc)
2028 			stmmac_display_ring((void *)priv->dma_etx, txsize, 1);
2029 		else
2030 			stmmac_display_ring((void *)priv->dma_tx, txsize, 0);
2031 
2032 		pr_debug(">>> frame to be transmitted: ");
2033 		print_pkt(skb->data, skb->len);
2034 	}
2035 	if (unlikely(stmmac_tx_avail(priv) <= (MAX_SKB_FRAGS + 1))) {
2036 		if (netif_msg_hw(priv))
2037 			pr_debug("%s: stop transmitted packets\n", __func__);
2038 		netif_stop_queue(dev);
2039 	}
2040 
2041 	dev->stats.tx_bytes += skb->len;
2042 
2043 	if (unlikely((skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) &&
2044 		     priv->hwts_tx_en)) {
2045 		/* declare that device is doing timestamping */
2046 		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
2047 		priv->hw->desc->enable_tx_timestamp(first);
2048 	}
2049 
2050 	if (!priv->hwts_tx_en)
2051 		skb_tx_timestamp(skb);
2052 
2053 	priv->hw->dma->enable_dma_transmission(priv->ioaddr);
2054 
2055 	spin_unlock(&priv->tx_lock);
2056 	return NETDEV_TX_OK;
2057 
2058 dma_map_err:
2059 	spin_unlock(&priv->tx_lock);
2060 	dev_err(priv->device, "Tx dma map failed\n");
2061 	dev_kfree_skb(skb);
2062 	priv->dev->stats.tx_dropped++;
2063 	return NETDEV_TX_OK;
2064 }
2065 
2066 static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
2067 {
2068 	struct ethhdr *ehdr;
2069 	u16 vlanid;
2070 
2071 	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
2072 	    NETIF_F_HW_VLAN_CTAG_RX &&
2073 	    !__vlan_get_tag(skb, &vlanid)) {
2074 		/* pop the vlan tag */
2075 		ehdr = (struct ethhdr *)skb->data;
2076 		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
2077 		skb_pull(skb, VLAN_HLEN);
2078 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
2079 	}
2080 }
2081 
2082 
2083 /**
2084  * stmmac_rx_refill - refill used skb preallocated buffers
2085  * @priv: driver private structure
2086  * Description : this is to reallocate the skb for the reception process
2087  * that is based on zero-copy.
2088  */
2089 static inline void stmmac_rx_refill(struct stmmac_priv *priv)
2090 {
2091 	unsigned int rxsize = priv->dma_rx_size;
2092 	int bfsize = priv->dma_buf_sz;
2093 
2094 	for (; priv->cur_rx - priv->dirty_rx > 0; priv->dirty_rx++) {
2095 		unsigned int entry = priv->dirty_rx % rxsize;
2096 		struct dma_desc *p;
2097 
2098 		if (priv->extend_desc)
2099 			p = (struct dma_desc *)(priv->dma_erx + entry);
2100 		else
2101 			p = priv->dma_rx + entry;
2102 
2103 		if (likely(priv->rx_skbuff[entry] == NULL)) {
2104 			struct sk_buff *skb;
2105 
2106 			skb = netdev_alloc_skb_ip_align(priv->dev, bfsize);
2107 
2108 			if (unlikely(skb == NULL))
2109 				break;
2110 
2111 			priv->rx_skbuff[entry] = skb;
2112 			priv->rx_skbuff_dma[entry] =
2113 			    dma_map_single(priv->device, skb->data, bfsize,
2114 					   DMA_FROM_DEVICE);
2115 			if (dma_mapping_error(priv->device,
2116 					      priv->rx_skbuff_dma[entry])) {
2117 				dev_err(priv->device, "Rx dma map failed\n");
2118 				dev_kfree_skb(skb);
2119 				break;
2120 			}
2121 			p->des2 = priv->rx_skbuff_dma[entry];
2122 
2123 			priv->hw->mode->refill_desc3(priv, p);
2124 
2125 			if (netif_msg_rx_status(priv))
2126 				pr_debug("\trefill entry #%d\n", entry);
2127 		}
2128 		wmb();
2129 		priv->hw->desc->set_rx_owner(p);
2130 		wmb();
2131 	}
2132 }
2133 
2134 /**
2135  * stmmac_rx - manage the receive process
2136  * @priv: driver private structure
2137  * @limit: napi bugget.
2138  * Description :  this the function called by the napi poll method.
2139  * It gets all the frames inside the ring.
2140  */
2141 static int stmmac_rx(struct stmmac_priv *priv, int limit)
2142 {
2143 	unsigned int rxsize = priv->dma_rx_size;
2144 	unsigned int entry = priv->cur_rx % rxsize;
2145 	unsigned int next_entry;
2146 	unsigned int count = 0;
2147 	int coe = priv->hw->rx_csum;
2148 
2149 	if (netif_msg_rx_status(priv)) {
2150 		pr_debug("%s: descriptor ring:\n", __func__);
2151 		if (priv->extend_desc)
2152 			stmmac_display_ring((void *)priv->dma_erx, rxsize, 1);
2153 		else
2154 			stmmac_display_ring((void *)priv->dma_rx, rxsize, 0);
2155 	}
2156 	while (count < limit) {
2157 		int status;
2158 		struct dma_desc *p;
2159 
2160 		if (priv->extend_desc)
2161 			p = (struct dma_desc *)(priv->dma_erx + entry);
2162 		else
2163 			p = priv->dma_rx + entry;
2164 
2165 		if (priv->hw->desc->get_rx_owner(p))
2166 			break;
2167 
2168 		count++;
2169 
2170 		next_entry = (++priv->cur_rx) % rxsize;
2171 		if (priv->extend_desc)
2172 			prefetch(priv->dma_erx + next_entry);
2173 		else
2174 			prefetch(priv->dma_rx + next_entry);
2175 
2176 		/* read the status of the incoming frame */
2177 		status = priv->hw->desc->rx_status(&priv->dev->stats,
2178 						   &priv->xstats, p);
2179 		if ((priv->extend_desc) && (priv->hw->desc->rx_extended_status))
2180 			priv->hw->desc->rx_extended_status(&priv->dev->stats,
2181 							   &priv->xstats,
2182 							   priv->dma_erx +
2183 							   entry);
2184 		if (unlikely(status == discard_frame)) {
2185 			priv->dev->stats.rx_errors++;
2186 			if (priv->hwts_rx_en && !priv->extend_desc) {
2187 				/* DESC2 & DESC3 will be overwitten by device
2188 				 * with timestamp value, hence reinitialize
2189 				 * them in stmmac_rx_refill() function so that
2190 				 * device can reuse it.
2191 				 */
2192 				priv->rx_skbuff[entry] = NULL;
2193 				dma_unmap_single(priv->device,
2194 						 priv->rx_skbuff_dma[entry],
2195 						 priv->dma_buf_sz,
2196 						 DMA_FROM_DEVICE);
2197 			}
2198 		} else {
2199 			struct sk_buff *skb;
2200 			int frame_len;
2201 
2202 			frame_len = priv->hw->desc->get_rx_frame_len(p, coe);
2203 
2204 			/* ACS is set; GMAC core strips PAD/FCS for IEEE 802.3
2205 			 * Type frames (LLC/LLC-SNAP)
2206 			 */
2207 			if (unlikely(status != llc_snap))
2208 				frame_len -= ETH_FCS_LEN;
2209 
2210 			if (netif_msg_rx_status(priv)) {
2211 				pr_debug("\tdesc: %p [entry %d] buff=0x%x\n",
2212 					 p, entry, p->des2);
2213 				if (frame_len > ETH_FRAME_LEN)
2214 					pr_debug("\tframe size %d, COE: %d\n",
2215 						 frame_len, status);
2216 			}
2217 			skb = priv->rx_skbuff[entry];
2218 			if (unlikely(!skb)) {
2219 				pr_err("%s: Inconsistent Rx descriptor chain\n",
2220 				       priv->dev->name);
2221 				priv->dev->stats.rx_dropped++;
2222 				break;
2223 			}
2224 			prefetch(skb->data - NET_IP_ALIGN);
2225 			priv->rx_skbuff[entry] = NULL;
2226 
2227 			stmmac_get_rx_hwtstamp(priv, entry, skb);
2228 
2229 			skb_put(skb, frame_len);
2230 			dma_unmap_single(priv->device,
2231 					 priv->rx_skbuff_dma[entry],
2232 					 priv->dma_buf_sz, DMA_FROM_DEVICE);
2233 
2234 			if (netif_msg_pktdata(priv)) {
2235 				pr_debug("frame received (%dbytes)", frame_len);
2236 				print_pkt(skb->data, frame_len);
2237 			}
2238 
2239 			stmmac_rx_vlan(priv->dev, skb);
2240 
2241 			skb->protocol = eth_type_trans(skb, priv->dev);
2242 
2243 			if (unlikely(!coe))
2244 				skb_checksum_none_assert(skb);
2245 			else
2246 				skb->ip_summed = CHECKSUM_UNNECESSARY;
2247 
2248 			napi_gro_receive(&priv->napi, skb);
2249 
2250 			priv->dev->stats.rx_packets++;
2251 			priv->dev->stats.rx_bytes += frame_len;
2252 		}
2253 		entry = next_entry;
2254 	}
2255 
2256 	stmmac_rx_refill(priv);
2257 
2258 	priv->xstats.rx_pkt_n += count;
2259 
2260 	return count;
2261 }
2262 
2263 /**
2264  *  stmmac_poll - stmmac poll method (NAPI)
2265  *  @napi : pointer to the napi structure.
2266  *  @budget : maximum number of packets that the current CPU can receive from
2267  *	      all interfaces.
2268  *  Description :
2269  *  To look at the incoming frames and clear the tx resources.
2270  */
2271 static int stmmac_poll(struct napi_struct *napi, int budget)
2272 {
2273 	struct stmmac_priv *priv = container_of(napi, struct stmmac_priv, napi);
2274 	int work_done = 0;
2275 
2276 	priv->xstats.napi_poll++;
2277 	stmmac_tx_clean(priv);
2278 
2279 	work_done = stmmac_rx(priv, budget);
2280 	if (work_done < budget) {
2281 		napi_complete(napi);
2282 		stmmac_enable_dma_irq(priv);
2283 	}
2284 	return work_done;
2285 }
2286 
2287 /**
2288  *  stmmac_tx_timeout
2289  *  @dev : Pointer to net device structure
2290  *  Description: this function is called when a packet transmission fails to
2291  *   complete within a reasonable time. The driver will mark the error in the
2292  *   netdev structure and arrange for the device to be reset to a sane state
2293  *   in order to transmit a new packet.
2294  */
2295 static void stmmac_tx_timeout(struct net_device *dev)
2296 {
2297 	struct stmmac_priv *priv = netdev_priv(dev);
2298 
2299 	/* Clear Tx resources and restart transmitting again */
2300 	stmmac_tx_err(priv);
2301 }
2302 
2303 /**
2304  *  stmmac_set_rx_mode - entry point for multicast addressing
2305  *  @dev : pointer to the device structure
2306  *  Description:
2307  *  This function is a driver entry point which gets called by the kernel
2308  *  whenever multicast addresses must be enabled/disabled.
2309  *  Return value:
2310  *  void.
2311  */
2312 static void stmmac_set_rx_mode(struct net_device *dev)
2313 {
2314 	struct stmmac_priv *priv = netdev_priv(dev);
2315 
2316 	priv->hw->mac->set_filter(priv->hw, dev);
2317 }
2318 
2319 /**
2320  *  stmmac_change_mtu - entry point to change MTU size for the device.
2321  *  @dev : device pointer.
2322  *  @new_mtu : the new MTU size for the device.
2323  *  Description: the Maximum Transfer Unit (MTU) is used by the network layer
2324  *  to drive packet transmission. Ethernet has an MTU of 1500 octets
2325  *  (ETH_DATA_LEN). This value can be changed with ifconfig.
2326  *  Return value:
2327  *  0 on success and an appropriate (-)ve integer as defined in errno.h
2328  *  file on failure.
2329  */
2330 static int stmmac_change_mtu(struct net_device *dev, int new_mtu)
2331 {
2332 	struct stmmac_priv *priv = netdev_priv(dev);
2333 	int max_mtu;
2334 
2335 	if (netif_running(dev)) {
2336 		pr_err("%s: must be stopped to change its MTU\n", dev->name);
2337 		return -EBUSY;
2338 	}
2339 
2340 	if (priv->plat->enh_desc)
2341 		max_mtu = JUMBO_LEN;
2342 	else
2343 		max_mtu = SKB_MAX_HEAD(NET_SKB_PAD + NET_IP_ALIGN);
2344 
2345 	if (priv->plat->maxmtu < max_mtu)
2346 		max_mtu = priv->plat->maxmtu;
2347 
2348 	if ((new_mtu < 46) || (new_mtu > max_mtu)) {
2349 		pr_err("%s: invalid MTU, max MTU is: %d\n", dev->name, max_mtu);
2350 		return -EINVAL;
2351 	}
2352 
2353 	dev->mtu = new_mtu;
2354 	netdev_update_features(dev);
2355 
2356 	return 0;
2357 }
2358 
2359 static netdev_features_t stmmac_fix_features(struct net_device *dev,
2360 					     netdev_features_t features)
2361 {
2362 	struct stmmac_priv *priv = netdev_priv(dev);
2363 
2364 	if (priv->plat->rx_coe == STMMAC_RX_COE_NONE)
2365 		features &= ~NETIF_F_RXCSUM;
2366 
2367 	if (!priv->plat->tx_coe)
2368 		features &= ~NETIF_F_ALL_CSUM;
2369 
2370 	/* Some GMAC devices have a bugged Jumbo frame support that
2371 	 * needs to have the Tx COE disabled for oversized frames
2372 	 * (due to limited buffer sizes). In this case we disable
2373 	 * the TX csum insertionin the TDES and not use SF.
2374 	 */
2375 	if (priv->plat->bugged_jumbo && (dev->mtu > ETH_DATA_LEN))
2376 		features &= ~NETIF_F_ALL_CSUM;
2377 
2378 	return features;
2379 }
2380 
2381 static int stmmac_set_features(struct net_device *netdev,
2382 			       netdev_features_t features)
2383 {
2384 	struct stmmac_priv *priv = netdev_priv(netdev);
2385 
2386 	/* Keep the COE Type in case of csum is supporting */
2387 	if (features & NETIF_F_RXCSUM)
2388 		priv->hw->rx_csum = priv->plat->rx_coe;
2389 	else
2390 		priv->hw->rx_csum = 0;
2391 	/* No check needed because rx_coe has been set before and it will be
2392 	 * fixed in case of issue.
2393 	 */
2394 	priv->hw->mac->rx_ipc(priv->hw);
2395 
2396 	return 0;
2397 }
2398 
2399 /**
2400  *  stmmac_interrupt - main ISR
2401  *  @irq: interrupt number.
2402  *  @dev_id: to pass the net device pointer.
2403  *  Description: this is the main driver interrupt service routine.
2404  *  It can call:
2405  *  o DMA service routine (to manage incoming frame reception and transmission
2406  *    status)
2407  *  o Core interrupts to manage: remote wake-up, management counter, LPI
2408  *    interrupts.
2409  */
2410 static irqreturn_t stmmac_interrupt(int irq, void *dev_id)
2411 {
2412 	struct net_device *dev = (struct net_device *)dev_id;
2413 	struct stmmac_priv *priv = netdev_priv(dev);
2414 
2415 	if (priv->irq_wake)
2416 		pm_wakeup_event(priv->device, 0);
2417 
2418 	if (unlikely(!dev)) {
2419 		pr_err("%s: invalid dev pointer\n", __func__);
2420 		return IRQ_NONE;
2421 	}
2422 
2423 	/* To handle GMAC own interrupts */
2424 	if (priv->plat->has_gmac) {
2425 		int status = priv->hw->mac->host_irq_status(priv->hw,
2426 							    &priv->xstats);
2427 		if (unlikely(status)) {
2428 			/* For LPI we need to save the tx status */
2429 			if (status & CORE_IRQ_TX_PATH_IN_LPI_MODE)
2430 				priv->tx_path_in_lpi_mode = true;
2431 			if (status & CORE_IRQ_TX_PATH_EXIT_LPI_MODE)
2432 				priv->tx_path_in_lpi_mode = false;
2433 		}
2434 	}
2435 
2436 	/* To handle DMA interrupts */
2437 	stmmac_dma_interrupt(priv);
2438 
2439 	return IRQ_HANDLED;
2440 }
2441 
2442 #ifdef CONFIG_NET_POLL_CONTROLLER
2443 /* Polling receive - used by NETCONSOLE and other diagnostic tools
2444  * to allow network I/O with interrupts disabled.
2445  */
2446 static void stmmac_poll_controller(struct net_device *dev)
2447 {
2448 	disable_irq(dev->irq);
2449 	stmmac_interrupt(dev->irq, dev);
2450 	enable_irq(dev->irq);
2451 }
2452 #endif
2453 
2454 /**
2455  *  stmmac_ioctl - Entry point for the Ioctl
2456  *  @dev: Device pointer.
2457  *  @rq: An IOCTL specefic structure, that can contain a pointer to
2458  *  a proprietary structure used to pass information to the driver.
2459  *  @cmd: IOCTL command
2460  *  Description:
2461  *  Currently it supports the phy_mii_ioctl(...) and HW time stamping.
2462  */
2463 static int stmmac_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
2464 {
2465 	struct stmmac_priv *priv = netdev_priv(dev);
2466 	int ret = -EOPNOTSUPP;
2467 
2468 	if (!netif_running(dev))
2469 		return -EINVAL;
2470 
2471 	switch (cmd) {
2472 	case SIOCGMIIPHY:
2473 	case SIOCGMIIREG:
2474 	case SIOCSMIIREG:
2475 		if (!priv->phydev)
2476 			return -EINVAL;
2477 		ret = phy_mii_ioctl(priv->phydev, rq, cmd);
2478 		break;
2479 	case SIOCSHWTSTAMP:
2480 		ret = stmmac_hwtstamp_ioctl(dev, rq);
2481 		break;
2482 	default:
2483 		break;
2484 	}
2485 
2486 	return ret;
2487 }
2488 
2489 #ifdef CONFIG_DEBUG_FS
2490 static struct dentry *stmmac_fs_dir;
2491 static struct dentry *stmmac_rings_status;
2492 static struct dentry *stmmac_dma_cap;
2493 
2494 static void sysfs_display_ring(void *head, int size, int extend_desc,
2495 			       struct seq_file *seq)
2496 {
2497 	int i;
2498 	struct dma_extended_desc *ep = (struct dma_extended_desc *)head;
2499 	struct dma_desc *p = (struct dma_desc *)head;
2500 
2501 	for (i = 0; i < size; i++) {
2502 		u64 x;
2503 		if (extend_desc) {
2504 			x = *(u64 *) ep;
2505 			seq_printf(seq, "%d [0x%x]: 0x%x 0x%x 0x%x 0x%x\n",
2506 				   i, (unsigned int)virt_to_phys(ep),
2507 				   (unsigned int)x, (unsigned int)(x >> 32),
2508 				   ep->basic.des2, ep->basic.des3);
2509 			ep++;
2510 		} else {
2511 			x = *(u64 *) p;
2512 			seq_printf(seq, "%d [0x%x]: 0x%x 0x%x 0x%x 0x%x\n",
2513 				   i, (unsigned int)virt_to_phys(ep),
2514 				   (unsigned int)x, (unsigned int)(x >> 32),
2515 				   p->des2, p->des3);
2516 			p++;
2517 		}
2518 		seq_printf(seq, "\n");
2519 	}
2520 }
2521 
2522 static int stmmac_sysfs_ring_read(struct seq_file *seq, void *v)
2523 {
2524 	struct net_device *dev = seq->private;
2525 	struct stmmac_priv *priv = netdev_priv(dev);
2526 	unsigned int txsize = priv->dma_tx_size;
2527 	unsigned int rxsize = priv->dma_rx_size;
2528 
2529 	if (priv->extend_desc) {
2530 		seq_printf(seq, "Extended RX descriptor ring:\n");
2531 		sysfs_display_ring((void *)priv->dma_erx, rxsize, 1, seq);
2532 		seq_printf(seq, "Extended TX descriptor ring:\n");
2533 		sysfs_display_ring((void *)priv->dma_etx, txsize, 1, seq);
2534 	} else {
2535 		seq_printf(seq, "RX descriptor ring:\n");
2536 		sysfs_display_ring((void *)priv->dma_rx, rxsize, 0, seq);
2537 		seq_printf(seq, "TX descriptor ring:\n");
2538 		sysfs_display_ring((void *)priv->dma_tx, txsize, 0, seq);
2539 	}
2540 
2541 	return 0;
2542 }
2543 
2544 static int stmmac_sysfs_ring_open(struct inode *inode, struct file *file)
2545 {
2546 	return single_open(file, stmmac_sysfs_ring_read, inode->i_private);
2547 }
2548 
2549 static const struct file_operations stmmac_rings_status_fops = {
2550 	.owner = THIS_MODULE,
2551 	.open = stmmac_sysfs_ring_open,
2552 	.read = seq_read,
2553 	.llseek = seq_lseek,
2554 	.release = single_release,
2555 };
2556 
2557 static int stmmac_sysfs_dma_cap_read(struct seq_file *seq, void *v)
2558 {
2559 	struct net_device *dev = seq->private;
2560 	struct stmmac_priv *priv = netdev_priv(dev);
2561 
2562 	if (!priv->hw_cap_support) {
2563 		seq_printf(seq, "DMA HW features not supported\n");
2564 		return 0;
2565 	}
2566 
2567 	seq_printf(seq, "==============================\n");
2568 	seq_printf(seq, "\tDMA HW features\n");
2569 	seq_printf(seq, "==============================\n");
2570 
2571 	seq_printf(seq, "\t10/100 Mbps %s\n",
2572 		   (priv->dma_cap.mbps_10_100) ? "Y" : "N");
2573 	seq_printf(seq, "\t1000 Mbps %s\n",
2574 		   (priv->dma_cap.mbps_1000) ? "Y" : "N");
2575 	seq_printf(seq, "\tHalf duple %s\n",
2576 		   (priv->dma_cap.half_duplex) ? "Y" : "N");
2577 	seq_printf(seq, "\tHash Filter: %s\n",
2578 		   (priv->dma_cap.hash_filter) ? "Y" : "N");
2579 	seq_printf(seq, "\tMultiple MAC address registers: %s\n",
2580 		   (priv->dma_cap.multi_addr) ? "Y" : "N");
2581 	seq_printf(seq, "\tPCS (TBI/SGMII/RTBI PHY interfatces): %s\n",
2582 		   (priv->dma_cap.pcs) ? "Y" : "N");
2583 	seq_printf(seq, "\tSMA (MDIO) Interface: %s\n",
2584 		   (priv->dma_cap.sma_mdio) ? "Y" : "N");
2585 	seq_printf(seq, "\tPMT Remote wake up: %s\n",
2586 		   (priv->dma_cap.pmt_remote_wake_up) ? "Y" : "N");
2587 	seq_printf(seq, "\tPMT Magic Frame: %s\n",
2588 		   (priv->dma_cap.pmt_magic_frame) ? "Y" : "N");
2589 	seq_printf(seq, "\tRMON module: %s\n",
2590 		   (priv->dma_cap.rmon) ? "Y" : "N");
2591 	seq_printf(seq, "\tIEEE 1588-2002 Time Stamp: %s\n",
2592 		   (priv->dma_cap.time_stamp) ? "Y" : "N");
2593 	seq_printf(seq, "\tIEEE 1588-2008 Advanced Time Stamp:%s\n",
2594 		   (priv->dma_cap.atime_stamp) ? "Y" : "N");
2595 	seq_printf(seq, "\t802.3az - Energy-Efficient Ethernet (EEE) %s\n",
2596 		   (priv->dma_cap.eee) ? "Y" : "N");
2597 	seq_printf(seq, "\tAV features: %s\n", (priv->dma_cap.av) ? "Y" : "N");
2598 	seq_printf(seq, "\tChecksum Offload in TX: %s\n",
2599 		   (priv->dma_cap.tx_coe) ? "Y" : "N");
2600 	seq_printf(seq, "\tIP Checksum Offload (type1) in RX: %s\n",
2601 		   (priv->dma_cap.rx_coe_type1) ? "Y" : "N");
2602 	seq_printf(seq, "\tIP Checksum Offload (type2) in RX: %s\n",
2603 		   (priv->dma_cap.rx_coe_type2) ? "Y" : "N");
2604 	seq_printf(seq, "\tRXFIFO > 2048bytes: %s\n",
2605 		   (priv->dma_cap.rxfifo_over_2048) ? "Y" : "N");
2606 	seq_printf(seq, "\tNumber of Additional RX channel: %d\n",
2607 		   priv->dma_cap.number_rx_channel);
2608 	seq_printf(seq, "\tNumber of Additional TX channel: %d\n",
2609 		   priv->dma_cap.number_tx_channel);
2610 	seq_printf(seq, "\tEnhanced descriptors: %s\n",
2611 		   (priv->dma_cap.enh_desc) ? "Y" : "N");
2612 
2613 	return 0;
2614 }
2615 
2616 static int stmmac_sysfs_dma_cap_open(struct inode *inode, struct file *file)
2617 {
2618 	return single_open(file, stmmac_sysfs_dma_cap_read, inode->i_private);
2619 }
2620 
2621 static const struct file_operations stmmac_dma_cap_fops = {
2622 	.owner = THIS_MODULE,
2623 	.open = stmmac_sysfs_dma_cap_open,
2624 	.read = seq_read,
2625 	.llseek = seq_lseek,
2626 	.release = single_release,
2627 };
2628 
2629 static int stmmac_init_fs(struct net_device *dev)
2630 {
2631 	/* Create debugfs entries */
2632 	stmmac_fs_dir = debugfs_create_dir(STMMAC_RESOURCE_NAME, NULL);
2633 
2634 	if (!stmmac_fs_dir || IS_ERR(stmmac_fs_dir)) {
2635 		pr_err("ERROR %s, debugfs create directory failed\n",
2636 		       STMMAC_RESOURCE_NAME);
2637 
2638 		return -ENOMEM;
2639 	}
2640 
2641 	/* Entry to report DMA RX/TX rings */
2642 	stmmac_rings_status = debugfs_create_file("descriptors_status",
2643 						  S_IRUGO, stmmac_fs_dir, dev,
2644 						  &stmmac_rings_status_fops);
2645 
2646 	if (!stmmac_rings_status || IS_ERR(stmmac_rings_status)) {
2647 		pr_info("ERROR creating stmmac ring debugfs file\n");
2648 		debugfs_remove(stmmac_fs_dir);
2649 
2650 		return -ENOMEM;
2651 	}
2652 
2653 	/* Entry to report the DMA HW features */
2654 	stmmac_dma_cap = debugfs_create_file("dma_cap", S_IRUGO, stmmac_fs_dir,
2655 					     dev, &stmmac_dma_cap_fops);
2656 
2657 	if (!stmmac_dma_cap || IS_ERR(stmmac_dma_cap)) {
2658 		pr_info("ERROR creating stmmac MMC debugfs file\n");
2659 		debugfs_remove(stmmac_rings_status);
2660 		debugfs_remove(stmmac_fs_dir);
2661 
2662 		return -ENOMEM;
2663 	}
2664 
2665 	return 0;
2666 }
2667 
2668 static void stmmac_exit_fs(void)
2669 {
2670 	debugfs_remove(stmmac_rings_status);
2671 	debugfs_remove(stmmac_dma_cap);
2672 	debugfs_remove(stmmac_fs_dir);
2673 }
2674 #endif /* CONFIG_DEBUG_FS */
2675 
2676 static const struct net_device_ops stmmac_netdev_ops = {
2677 	.ndo_open = stmmac_open,
2678 	.ndo_start_xmit = stmmac_xmit,
2679 	.ndo_stop = stmmac_release,
2680 	.ndo_change_mtu = stmmac_change_mtu,
2681 	.ndo_fix_features = stmmac_fix_features,
2682 	.ndo_set_features = stmmac_set_features,
2683 	.ndo_set_rx_mode = stmmac_set_rx_mode,
2684 	.ndo_tx_timeout = stmmac_tx_timeout,
2685 	.ndo_do_ioctl = stmmac_ioctl,
2686 #ifdef CONFIG_NET_POLL_CONTROLLER
2687 	.ndo_poll_controller = stmmac_poll_controller,
2688 #endif
2689 	.ndo_set_mac_address = eth_mac_addr,
2690 };
2691 
2692 /**
2693  *  stmmac_hw_init - Init the MAC device
2694  *  @priv: driver private structure
2695  *  Description: this function is to configure the MAC device according to
2696  *  some platform parameters or the HW capability register. It prepares the
2697  *  driver to use either ring or chain modes and to setup either enhanced or
2698  *  normal descriptors.
2699  */
2700 static int stmmac_hw_init(struct stmmac_priv *priv)
2701 {
2702 	struct mac_device_info *mac;
2703 
2704 	/* Identify the MAC HW device */
2705 	if (priv->plat->has_gmac) {
2706 		priv->dev->priv_flags |= IFF_UNICAST_FLT;
2707 		mac = dwmac1000_setup(priv->ioaddr,
2708 				      priv->plat->multicast_filter_bins,
2709 				      priv->plat->unicast_filter_entries);
2710 	} else {
2711 		mac = dwmac100_setup(priv->ioaddr);
2712 	}
2713 	if (!mac)
2714 		return -ENOMEM;
2715 
2716 	priv->hw = mac;
2717 
2718 	/* Get and dump the chip ID */
2719 	priv->synopsys_id = stmmac_get_synopsys_id(priv);
2720 
2721 	/* To use the chained or ring mode */
2722 	if (chain_mode) {
2723 		priv->hw->mode = &chain_mode_ops;
2724 		pr_info(" Chain mode enabled\n");
2725 		priv->mode = STMMAC_CHAIN_MODE;
2726 	} else {
2727 		priv->hw->mode = &ring_mode_ops;
2728 		pr_info(" Ring mode enabled\n");
2729 		priv->mode = STMMAC_RING_MODE;
2730 	}
2731 
2732 	/* Get the HW capability (new GMAC newer than 3.50a) */
2733 	priv->hw_cap_support = stmmac_get_hw_features(priv);
2734 	if (priv->hw_cap_support) {
2735 		pr_info(" DMA HW capability register supported");
2736 
2737 		/* We can override some gmac/dma configuration fields: e.g.
2738 		 * enh_desc, tx_coe (e.g. that are passed through the
2739 		 * platform) with the values from the HW capability
2740 		 * register (if supported).
2741 		 */
2742 		priv->plat->enh_desc = priv->dma_cap.enh_desc;
2743 		priv->plat->pmt = priv->dma_cap.pmt_remote_wake_up;
2744 
2745 		priv->plat->tx_coe = priv->dma_cap.tx_coe;
2746 
2747 		if (priv->dma_cap.rx_coe_type2)
2748 			priv->plat->rx_coe = STMMAC_RX_COE_TYPE2;
2749 		else if (priv->dma_cap.rx_coe_type1)
2750 			priv->plat->rx_coe = STMMAC_RX_COE_TYPE1;
2751 
2752 	} else
2753 		pr_info(" No HW DMA feature register supported");
2754 
2755 	/* To use alternate (extended) or normal descriptor structures */
2756 	stmmac_selec_desc_mode(priv);
2757 
2758 	if (priv->plat->rx_coe) {
2759 		priv->hw->rx_csum = priv->plat->rx_coe;
2760 		pr_info(" RX Checksum Offload Engine supported (type %d)\n",
2761 			priv->plat->rx_coe);
2762 	}
2763 	if (priv->plat->tx_coe)
2764 		pr_info(" TX Checksum insertion supported\n");
2765 
2766 	if (priv->plat->pmt) {
2767 		pr_info(" Wake-Up On Lan supported\n");
2768 		device_set_wakeup_capable(priv->device, 1);
2769 	}
2770 
2771 	return 0;
2772 }
2773 
2774 /**
2775  * stmmac_dvr_probe
2776  * @device: device pointer
2777  * @plat_dat: platform data pointer
2778  * @addr: iobase memory address
2779  * Description: this is the main probe function used to
2780  * call the alloc_etherdev, allocate the priv structure.
2781  * Return:
2782  * on success the new private structure is returned, otherwise the error
2783  * pointer.
2784  */
2785 struct stmmac_priv *stmmac_dvr_probe(struct device *device,
2786 				     struct plat_stmmacenet_data *plat_dat,
2787 				     void __iomem *addr)
2788 {
2789 	int ret = 0;
2790 	struct net_device *ndev = NULL;
2791 	struct stmmac_priv *priv;
2792 
2793 	ndev = alloc_etherdev(sizeof(struct stmmac_priv));
2794 	if (!ndev)
2795 		return ERR_PTR(-ENOMEM);
2796 
2797 	SET_NETDEV_DEV(ndev, device);
2798 
2799 	priv = netdev_priv(ndev);
2800 	priv->device = device;
2801 	priv->dev = ndev;
2802 
2803 	stmmac_set_ethtool_ops(ndev);
2804 	priv->pause = pause;
2805 	priv->plat = plat_dat;
2806 	priv->ioaddr = addr;
2807 	priv->dev->base_addr = (unsigned long)addr;
2808 
2809 	/* Verify driver arguments */
2810 	stmmac_verify_args();
2811 
2812 	/* Override with kernel parameters if supplied XXX CRS XXX
2813 	 * this needs to have multiple instances
2814 	 */
2815 	if ((phyaddr >= 0) && (phyaddr <= 31))
2816 		priv->plat->phy_addr = phyaddr;
2817 
2818 	priv->stmmac_clk = devm_clk_get(priv->device, STMMAC_RESOURCE_NAME);
2819 	if (IS_ERR(priv->stmmac_clk)) {
2820 		dev_warn(priv->device, "%s: warning: cannot get CSR clock\n",
2821 			 __func__);
2822 		/* If failed to obtain stmmac_clk and specific clk_csr value
2823 		 * is NOT passed from the platform, probe fail.
2824 		 */
2825 		if (!priv->plat->clk_csr) {
2826 			ret = PTR_ERR(priv->stmmac_clk);
2827 			goto error_clk_get;
2828 		} else {
2829 			priv->stmmac_clk = NULL;
2830 		}
2831 	}
2832 	clk_prepare_enable(priv->stmmac_clk);
2833 
2834 	priv->stmmac_rst = devm_reset_control_get(priv->device,
2835 						  STMMAC_RESOURCE_NAME);
2836 	if (IS_ERR(priv->stmmac_rst)) {
2837 		if (PTR_ERR(priv->stmmac_rst) == -EPROBE_DEFER) {
2838 			ret = -EPROBE_DEFER;
2839 			goto error_hw_init;
2840 		}
2841 		dev_info(priv->device, "no reset control found\n");
2842 		priv->stmmac_rst = NULL;
2843 	}
2844 	if (priv->stmmac_rst)
2845 		reset_control_deassert(priv->stmmac_rst);
2846 
2847 	/* Init MAC and get the capabilities */
2848 	ret = stmmac_hw_init(priv);
2849 	if (ret)
2850 		goto error_hw_init;
2851 
2852 	ndev->netdev_ops = &stmmac_netdev_ops;
2853 
2854 	ndev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
2855 			    NETIF_F_RXCSUM;
2856 	ndev->features |= ndev->hw_features | NETIF_F_HIGHDMA;
2857 	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
2858 #ifdef STMMAC_VLAN_TAG_USED
2859 	/* Both mac100 and gmac support receive VLAN tag detection */
2860 	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX;
2861 #endif
2862 	priv->msg_enable = netif_msg_init(debug, default_msg_level);
2863 
2864 	if (flow_ctrl)
2865 		priv->flow_ctrl = FLOW_AUTO;	/* RX/TX pause on */
2866 
2867 	/* Rx Watchdog is available in the COREs newer than the 3.40.
2868 	 * In some case, for example on bugged HW this feature
2869 	 * has to be disable and this can be done by passing the
2870 	 * riwt_off field from the platform.
2871 	 */
2872 	if ((priv->synopsys_id >= DWMAC_CORE_3_50) && (!priv->plat->riwt_off)) {
2873 		priv->use_riwt = 1;
2874 		pr_info(" Enable RX Mitigation via HW Watchdog Timer\n");
2875 	}
2876 
2877 	netif_napi_add(ndev, &priv->napi, stmmac_poll, 64);
2878 
2879 	spin_lock_init(&priv->lock);
2880 	spin_lock_init(&priv->tx_lock);
2881 
2882 	ret = register_netdev(ndev);
2883 	if (ret) {
2884 		pr_err("%s: ERROR %i registering the device\n", __func__, ret);
2885 		goto error_netdev_register;
2886 	}
2887 
2888 	/* If a specific clk_csr value is passed from the platform
2889 	 * this means that the CSR Clock Range selection cannot be
2890 	 * changed at run-time and it is fixed. Viceversa the driver'll try to
2891 	 * set the MDC clock dynamically according to the csr actual
2892 	 * clock input.
2893 	 */
2894 	if (!priv->plat->clk_csr)
2895 		stmmac_clk_csr_set(priv);
2896 	else
2897 		priv->clk_csr = priv->plat->clk_csr;
2898 
2899 	stmmac_check_pcs_mode(priv);
2900 
2901 	if (priv->pcs != STMMAC_PCS_RGMII && priv->pcs != STMMAC_PCS_TBI &&
2902 	    priv->pcs != STMMAC_PCS_RTBI) {
2903 		/* MDIO bus Registration */
2904 		ret = stmmac_mdio_register(ndev);
2905 		if (ret < 0) {
2906 			pr_debug("%s: MDIO bus (id: %d) registration failed",
2907 				 __func__, priv->plat->bus_id);
2908 			goto error_mdio_register;
2909 		}
2910 	}
2911 
2912 	return priv;
2913 
2914 error_mdio_register:
2915 	unregister_netdev(ndev);
2916 error_netdev_register:
2917 	netif_napi_del(&priv->napi);
2918 error_hw_init:
2919 	clk_disable_unprepare(priv->stmmac_clk);
2920 error_clk_get:
2921 	free_netdev(ndev);
2922 
2923 	return ERR_PTR(ret);
2924 }
2925 EXPORT_SYMBOL_GPL(stmmac_dvr_probe);
2926 
2927 /**
2928  * stmmac_dvr_remove
2929  * @ndev: net device pointer
2930  * Description: this function resets the TX/RX processes, disables the MAC RX/TX
2931  * changes the link status, releases the DMA descriptor rings.
2932  */
2933 int stmmac_dvr_remove(struct net_device *ndev)
2934 {
2935 	struct stmmac_priv *priv = netdev_priv(ndev);
2936 
2937 	pr_info("%s:\n\tremoving driver", __func__);
2938 
2939 	priv->hw->dma->stop_rx(priv->ioaddr);
2940 	priv->hw->dma->stop_tx(priv->ioaddr);
2941 
2942 	stmmac_set_mac(priv->ioaddr, false);
2943 	if (priv->pcs != STMMAC_PCS_RGMII && priv->pcs != STMMAC_PCS_TBI &&
2944 	    priv->pcs != STMMAC_PCS_RTBI)
2945 		stmmac_mdio_unregister(ndev);
2946 	netif_carrier_off(ndev);
2947 	unregister_netdev(ndev);
2948 	if (priv->stmmac_rst)
2949 		reset_control_assert(priv->stmmac_rst);
2950 	clk_disable_unprepare(priv->stmmac_clk);
2951 	free_netdev(ndev);
2952 
2953 	return 0;
2954 }
2955 EXPORT_SYMBOL_GPL(stmmac_dvr_remove);
2956 
2957 /**
2958  * stmmac_suspend - suspend callback
2959  * @ndev: net device pointer
2960  * Description: this is the function to suspend the device and it is called
2961  * by the platform driver to stop the network queue, release the resources,
2962  * program the PMT register (for WoL), clean and release driver resources.
2963  */
2964 int stmmac_suspend(struct net_device *ndev)
2965 {
2966 	struct stmmac_priv *priv = netdev_priv(ndev);
2967 	unsigned long flags;
2968 
2969 	if (!ndev || !netif_running(ndev))
2970 		return 0;
2971 
2972 	if (priv->phydev)
2973 		phy_stop(priv->phydev);
2974 
2975 	spin_lock_irqsave(&priv->lock, flags);
2976 
2977 	netif_device_detach(ndev);
2978 	netif_stop_queue(ndev);
2979 
2980 	napi_disable(&priv->napi);
2981 
2982 	/* Stop TX/RX DMA */
2983 	priv->hw->dma->stop_tx(priv->ioaddr);
2984 	priv->hw->dma->stop_rx(priv->ioaddr);
2985 
2986 	stmmac_clear_descriptors(priv);
2987 
2988 	/* Enable Power down mode by programming the PMT regs */
2989 	if (device_may_wakeup(priv->device)) {
2990 		priv->hw->mac->pmt(priv->hw, priv->wolopts);
2991 		priv->irq_wake = 1;
2992 	} else {
2993 		stmmac_set_mac(priv->ioaddr, false);
2994 		pinctrl_pm_select_sleep_state(priv->device);
2995 		/* Disable clock in case of PWM is off */
2996 		clk_disable(priv->stmmac_clk);
2997 	}
2998 	spin_unlock_irqrestore(&priv->lock, flags);
2999 
3000 	priv->oldlink = 0;
3001 	priv->speed = 0;
3002 	priv->oldduplex = -1;
3003 	return 0;
3004 }
3005 EXPORT_SYMBOL_GPL(stmmac_suspend);
3006 
3007 /**
3008  * stmmac_resume - resume callback
3009  * @ndev: net device pointer
3010  * Description: when resume this function is invoked to setup the DMA and CORE
3011  * in a usable state.
3012  */
3013 int stmmac_resume(struct net_device *ndev)
3014 {
3015 	struct stmmac_priv *priv = netdev_priv(ndev);
3016 	unsigned long flags;
3017 
3018 	if (!netif_running(ndev))
3019 		return 0;
3020 
3021 	spin_lock_irqsave(&priv->lock, flags);
3022 
3023 	/* Power Down bit, into the PM register, is cleared
3024 	 * automatically as soon as a magic packet or a Wake-up frame
3025 	 * is received. Anyway, it's better to manually clear
3026 	 * this bit because it can generate problems while resuming
3027 	 * from another devices (e.g. serial console).
3028 	 */
3029 	if (device_may_wakeup(priv->device)) {
3030 		priv->hw->mac->pmt(priv->hw, 0);
3031 		priv->irq_wake = 0;
3032 	} else {
3033 		pinctrl_pm_select_default_state(priv->device);
3034 		/* enable the clk prevously disabled */
3035 		clk_enable(priv->stmmac_clk);
3036 		/* reset the phy so that it's ready */
3037 		if (priv->mii)
3038 			stmmac_mdio_reset(priv->mii);
3039 	}
3040 
3041 	netif_device_attach(ndev);
3042 
3043 	init_dma_desc_rings(ndev, GFP_ATOMIC);
3044 	stmmac_hw_setup(ndev, false);
3045 	stmmac_init_tx_coalesce(priv);
3046 
3047 	napi_enable(&priv->napi);
3048 
3049 	netif_start_queue(ndev);
3050 
3051 	spin_unlock_irqrestore(&priv->lock, flags);
3052 
3053 	if (priv->phydev)
3054 		phy_start(priv->phydev);
3055 
3056 	return 0;
3057 }
3058 EXPORT_SYMBOL_GPL(stmmac_resume);
3059 
3060 #ifndef MODULE
3061 static int __init stmmac_cmdline_opt(char *str)
3062 {
3063 	char *opt;
3064 
3065 	if (!str || !*str)
3066 		return -EINVAL;
3067 	while ((opt = strsep(&str, ",")) != NULL) {
3068 		if (!strncmp(opt, "debug:", 6)) {
3069 			if (kstrtoint(opt + 6, 0, &debug))
3070 				goto err;
3071 		} else if (!strncmp(opt, "phyaddr:", 8)) {
3072 			if (kstrtoint(opt + 8, 0, &phyaddr))
3073 				goto err;
3074 		} else if (!strncmp(opt, "dma_txsize:", 11)) {
3075 			if (kstrtoint(opt + 11, 0, &dma_txsize))
3076 				goto err;
3077 		} else if (!strncmp(opt, "dma_rxsize:", 11)) {
3078 			if (kstrtoint(opt + 11, 0, &dma_rxsize))
3079 				goto err;
3080 		} else if (!strncmp(opt, "buf_sz:", 7)) {
3081 			if (kstrtoint(opt + 7, 0, &buf_sz))
3082 				goto err;
3083 		} else if (!strncmp(opt, "tc:", 3)) {
3084 			if (kstrtoint(opt + 3, 0, &tc))
3085 				goto err;
3086 		} else if (!strncmp(opt, "watchdog:", 9)) {
3087 			if (kstrtoint(opt + 9, 0, &watchdog))
3088 				goto err;
3089 		} else if (!strncmp(opt, "flow_ctrl:", 10)) {
3090 			if (kstrtoint(opt + 10, 0, &flow_ctrl))
3091 				goto err;
3092 		} else if (!strncmp(opt, "pause:", 6)) {
3093 			if (kstrtoint(opt + 6, 0, &pause))
3094 				goto err;
3095 		} else if (!strncmp(opt, "eee_timer:", 10)) {
3096 			if (kstrtoint(opt + 10, 0, &eee_timer))
3097 				goto err;
3098 		} else if (!strncmp(opt, "chain_mode:", 11)) {
3099 			if (kstrtoint(opt + 11, 0, &chain_mode))
3100 				goto err;
3101 		}
3102 	}
3103 	return 0;
3104 
3105 err:
3106 	pr_err("%s: ERROR broken module parameter conversion", __func__);
3107 	return -EINVAL;
3108 }
3109 
3110 __setup("stmmaceth=", stmmac_cmdline_opt);
3111 #endif /* MODULE */
3112 
3113 MODULE_DESCRIPTION("STMMAC 10/100/1000 Ethernet device driver");
3114 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
3115 MODULE_LICENSE("GPL");
3116