1 /* Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.
2  *
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License version 2 and
5  * only version 2 as published by the Free Software Foundation.
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10  * GNU General Public License for more details.
11  */
12 
13 /* Qualcomm Technologies, Inc. EMAC Ethernet Controller MAC layer support
14  */
15 
16 #include <linux/tcp.h>
17 #include <linux/ip.h>
18 #include <linux/ipv6.h>
19 #include <linux/crc32.h>
20 #include <linux/if_vlan.h>
21 #include <linux/jiffies.h>
22 #include <linux/phy.h>
23 #include <linux/of.h>
24 #include <net/ip6_checksum.h>
25 #include "emac.h"
26 #include "emac-sgmii.h"
27 
28 /* EMAC_MAC_CTRL */
29 #define SINGLE_PAUSE_MODE       	0x10000000
30 #define DEBUG_MODE                      0x08000000
31 #define BROAD_EN                        0x04000000
32 #define MULTI_ALL                       0x02000000
33 #define RX_CHKSUM_EN                    0x01000000
34 #define HUGE                            0x00800000
35 #define SPEED(x)			(((x) & 0x3) << 20)
36 #define SPEED_MASK			SPEED(0x3)
37 #define SIMR                            0x00080000
38 #define TPAUSE                          0x00010000
39 #define PROM_MODE                       0x00008000
40 #define VLAN_STRIP                      0x00004000
41 #define PRLEN_BMSK                      0x00003c00
42 #define PRLEN_SHFT                      10
43 #define HUGEN                           0x00000200
44 #define FLCHK                           0x00000100
45 #define PCRCE                           0x00000080
46 #define CRCE                            0x00000040
47 #define FULLD                           0x00000020
48 #define MAC_LP_EN                       0x00000010
49 #define RXFC                            0x00000008
50 #define TXFC                            0x00000004
51 #define RXEN                            0x00000002
52 #define TXEN                            0x00000001
53 
54 /* EMAC_DESC_CTRL_3 */
55 #define RFD_RING_SIZE_BMSK                                       0xfff
56 
57 /* EMAC_DESC_CTRL_4 */
58 #define RX_BUFFER_SIZE_BMSK                                     0xffff
59 
60 /* EMAC_DESC_CTRL_6 */
61 #define RRD_RING_SIZE_BMSK                                       0xfff
62 
63 /* EMAC_DESC_CTRL_9 */
64 #define TPD_RING_SIZE_BMSK                                      0xffff
65 
66 /* EMAC_TXQ_CTRL_0 */
67 #define NUM_TXF_BURST_PREF_BMSK                             0xffff0000
68 #define NUM_TXF_BURST_PREF_SHFT                                     16
69 #define LS_8023_SP                                                0x80
70 #define TXQ_MODE                                                  0x40
71 #define TXQ_EN                                                    0x20
72 #define IP_OP_SP                                                  0x10
73 #define NUM_TPD_BURST_PREF_BMSK                                    0xf
74 #define NUM_TPD_BURST_PREF_SHFT                                      0
75 
76 /* EMAC_TXQ_CTRL_1 */
77 #define JUMBO_TASK_OFFLOAD_THRESHOLD_BMSK                        0x7ff
78 
79 /* EMAC_TXQ_CTRL_2 */
80 #define TXF_HWM_BMSK                                         0xfff0000
81 #define TXF_LWM_BMSK                                             0xfff
82 
83 /* EMAC_RXQ_CTRL_0 */
84 #define RXQ_EN                                                 BIT(31)
85 #define CUT_THRU_EN                                            BIT(30)
86 #define RSS_HASH_EN                                            BIT(29)
87 #define NUM_RFD_BURST_PREF_BMSK                              0x3f00000
88 #define NUM_RFD_BURST_PREF_SHFT                                     20
89 #define IDT_TABLE_SIZE_BMSK                                    0x1ff00
90 #define IDT_TABLE_SIZE_SHFT                                          8
91 #define SP_IPV6                                                   0x80
92 
93 /* EMAC_RXQ_CTRL_1 */
94 #define JUMBO_1KAH_BMSK                                         0xf000
95 #define JUMBO_1KAH_SHFT                                             12
96 #define RFD_PREF_LOW_TH                                           0x10
97 #define RFD_PREF_LOW_THRESHOLD_BMSK                              0xfc0
98 #define RFD_PREF_LOW_THRESHOLD_SHFT                                  6
99 #define RFD_PREF_UP_TH                                            0x10
100 #define RFD_PREF_UP_THRESHOLD_BMSK                                0x3f
101 #define RFD_PREF_UP_THRESHOLD_SHFT                                   0
102 
103 /* EMAC_RXQ_CTRL_2 */
104 #define RXF_DOF_THRESFHOLD                                       0x1a0
105 #define RXF_DOF_THRESHOLD_BMSK                               0xfff0000
106 #define RXF_DOF_THRESHOLD_SHFT                                      16
107 #define RXF_UOF_THRESFHOLD                                        0xbe
108 #define RXF_UOF_THRESHOLD_BMSK                                   0xfff
109 #define RXF_UOF_THRESHOLD_SHFT                                       0
110 
111 /* EMAC_RXQ_CTRL_3 */
112 #define RXD_TIMER_BMSK                                      0xffff0000
113 #define RXD_THRESHOLD_BMSK                                       0xfff
114 #define RXD_THRESHOLD_SHFT                                           0
115 
116 /* EMAC_DMA_CTRL */
117 #define DMAW_DLY_CNT_BMSK                                      0xf0000
118 #define DMAW_DLY_CNT_SHFT                                           16
119 #define DMAR_DLY_CNT_BMSK                                       0xf800
120 #define DMAR_DLY_CNT_SHFT                                           11
121 #define DMAR_REQ_PRI                                             0x400
122 #define REGWRBLEN_BMSK                                           0x380
123 #define REGWRBLEN_SHFT                                               7
124 #define REGRDBLEN_BMSK                                            0x70
125 #define REGRDBLEN_SHFT                                               4
126 #define OUT_ORDER_MODE                                             0x4
127 #define ENH_ORDER_MODE                                             0x2
128 #define IN_ORDER_MODE                                              0x1
129 
130 /* EMAC_MAILBOX_13 */
131 #define RFD3_PROC_IDX_BMSK                                   0xfff0000
132 #define RFD3_PROC_IDX_SHFT                                          16
133 #define RFD3_PROD_IDX_BMSK                                       0xfff
134 #define RFD3_PROD_IDX_SHFT                                           0
135 
136 /* EMAC_MAILBOX_2 */
137 #define NTPD_CONS_IDX_BMSK                                  0xffff0000
138 #define NTPD_CONS_IDX_SHFT                                          16
139 
140 /* EMAC_MAILBOX_3 */
141 #define RFD0_CONS_IDX_BMSK                                       0xfff
142 #define RFD0_CONS_IDX_SHFT                                           0
143 
144 /* EMAC_MAILBOX_11 */
145 #define H3TPD_PROD_IDX_BMSK                                 0xffff0000
146 #define H3TPD_PROD_IDX_SHFT                                         16
147 
148 /* EMAC_AXI_MAST_CTRL */
149 #define DATA_BYTE_SWAP                                             0x8
150 #define MAX_BOUND                                                  0x2
151 #define MAX_BTYPE                                                  0x1
152 
153 /* EMAC_MAILBOX_12 */
154 #define H3TPD_CONS_IDX_BMSK                                 0xffff0000
155 #define H3TPD_CONS_IDX_SHFT                                         16
156 
157 /* EMAC_MAILBOX_9 */
158 #define H2TPD_PROD_IDX_BMSK                                     0xffff
159 #define H2TPD_PROD_IDX_SHFT                                          0
160 
161 /* EMAC_MAILBOX_10 */
162 #define H1TPD_CONS_IDX_BMSK                                 0xffff0000
163 #define H1TPD_CONS_IDX_SHFT                                         16
164 #define H2TPD_CONS_IDX_BMSK                                     0xffff
165 #define H2TPD_CONS_IDX_SHFT                                          0
166 
167 /* EMAC_ATHR_HEADER_CTRL */
168 #define HEADER_CNT_EN                                              0x2
169 #define HEADER_ENABLE                                              0x1
170 
171 /* EMAC_MAILBOX_0 */
172 #define RFD0_PROC_IDX_BMSK                                   0xfff0000
173 #define RFD0_PROC_IDX_SHFT                                          16
174 #define RFD0_PROD_IDX_BMSK                                       0xfff
175 #define RFD0_PROD_IDX_SHFT                                           0
176 
177 /* EMAC_MAILBOX_5 */
178 #define RFD1_PROC_IDX_BMSK                                   0xfff0000
179 #define RFD1_PROC_IDX_SHFT                                          16
180 #define RFD1_PROD_IDX_BMSK                                       0xfff
181 #define RFD1_PROD_IDX_SHFT                                           0
182 
183 /* EMAC_MISC_CTRL */
184 #define RX_UNCPL_INT_EN                                            0x1
185 
186 /* EMAC_MAILBOX_7 */
187 #define RFD2_CONS_IDX_BMSK                                   0xfff0000
188 #define RFD2_CONS_IDX_SHFT                                          16
189 #define RFD1_CONS_IDX_BMSK                                       0xfff
190 #define RFD1_CONS_IDX_SHFT                                           0
191 
192 /* EMAC_MAILBOX_8 */
193 #define RFD3_CONS_IDX_BMSK                                       0xfff
194 #define RFD3_CONS_IDX_SHFT                                           0
195 
196 /* EMAC_MAILBOX_15 */
197 #define NTPD_PROD_IDX_BMSK                                      0xffff
198 #define NTPD_PROD_IDX_SHFT                                           0
199 
200 /* EMAC_MAILBOX_16 */
201 #define H1TPD_PROD_IDX_BMSK                                     0xffff
202 #define H1TPD_PROD_IDX_SHFT                                          0
203 
204 #define RXQ0_RSS_HSTYP_IPV6_TCP_EN                                0x20
205 #define RXQ0_RSS_HSTYP_IPV6_EN                                    0x10
206 #define RXQ0_RSS_HSTYP_IPV4_TCP_EN                                 0x8
207 #define RXQ0_RSS_HSTYP_IPV4_EN                                     0x4
208 
209 /* EMAC_EMAC_WRAPPER_TX_TS_INX */
210 #define EMAC_WRAPPER_TX_TS_EMPTY                               BIT(31)
211 #define EMAC_WRAPPER_TX_TS_INX_BMSK                             0xffff
212 
213 struct emac_skb_cb {
214 	u32           tpd_idx;
215 	unsigned long jiffies;
216 };
217 
218 #define EMAC_SKB_CB(skb)	((struct emac_skb_cb *)(skb)->cb)
219 #define EMAC_RSS_IDT_SIZE	256
220 #define JUMBO_1KAH		0x4
221 #define RXD_TH			0x100
222 #define EMAC_TPD_LAST_FRAGMENT	0x80000000
223 #define EMAC_TPD_TSTAMP_SAVE	0x80000000
224 
225 /* EMAC Errors in emac_rrd.word[3] */
226 #define EMAC_RRD_L4F		BIT(14)
227 #define EMAC_RRD_IPF		BIT(15)
228 #define EMAC_RRD_CRC		BIT(21)
229 #define EMAC_RRD_FAE		BIT(22)
230 #define EMAC_RRD_TRN		BIT(23)
231 #define EMAC_RRD_RNT		BIT(24)
232 #define EMAC_RRD_INC		BIT(25)
233 #define EMAC_RRD_FOV		BIT(29)
234 #define EMAC_RRD_LEN		BIT(30)
235 
236 /* Error bits that will result in a received frame being discarded */
237 #define EMAC_RRD_ERROR (EMAC_RRD_IPF | EMAC_RRD_CRC | EMAC_RRD_FAE | \
238 			EMAC_RRD_TRN | EMAC_RRD_RNT | EMAC_RRD_INC | \
239 			EMAC_RRD_FOV | EMAC_RRD_LEN)
240 #define EMAC_RRD_STATS_DW_IDX 3
241 
242 #define EMAC_RRD(RXQ, SIZE, IDX)	((RXQ)->rrd.v_addr + (SIZE * (IDX)))
243 #define EMAC_RFD(RXQ, SIZE, IDX)	((RXQ)->rfd.v_addr + (SIZE * (IDX)))
244 #define EMAC_TPD(TXQ, SIZE, IDX)	((TXQ)->tpd.v_addr + (SIZE * (IDX)))
245 
246 #define GET_RFD_BUFFER(RXQ, IDX)	(&((RXQ)->rfd.rfbuff[(IDX)]))
247 #define GET_TPD_BUFFER(RTQ, IDX)	(&((RTQ)->tpd.tpbuff[(IDX)]))
248 
249 #define EMAC_TX_POLL_HWTXTSTAMP_THRESHOLD	8
250 
251 #define ISR_RX_PKT      (\
252 	RX_PKT_INT0     |\
253 	RX_PKT_INT1     |\
254 	RX_PKT_INT2     |\
255 	RX_PKT_INT3)
256 
257 void emac_mac_multicast_addr_set(struct emac_adapter *adpt, u8 *addr)
258 {
259 	u32 crc32, bit, reg, mta;
260 
261 	/* Calculate the CRC of the MAC address */
262 	crc32 = ether_crc(ETH_ALEN, addr);
263 
264 	/* The HASH Table is an array of 2 32-bit registers. It is
265 	 * treated like an array of 64 bits (BitArray[hash_value]).
266 	 * Use the upper 6 bits of the above CRC as the hash value.
267 	 */
268 	reg = (crc32 >> 31) & 0x1;
269 	bit = (crc32 >> 26) & 0x1F;
270 
271 	mta = readl(adpt->base + EMAC_HASH_TAB_REG0 + (reg << 2));
272 	mta |= BIT(bit);
273 	writel(mta, adpt->base + EMAC_HASH_TAB_REG0 + (reg << 2));
274 }
275 
276 void emac_mac_multicast_addr_clear(struct emac_adapter *adpt)
277 {
278 	writel(0, adpt->base + EMAC_HASH_TAB_REG0);
279 	writel(0, adpt->base + EMAC_HASH_TAB_REG1);
280 }
281 
282 /* definitions for RSS */
283 #define EMAC_RSS_KEY(_i, _type) \
284 		(EMAC_RSS_KEY0 + ((_i) * sizeof(_type)))
285 #define EMAC_RSS_TBL(_i, _type) \
286 		(EMAC_IDT_TABLE0 + ((_i) * sizeof(_type)))
287 
288 /* Config MAC modes */
289 void emac_mac_mode_config(struct emac_adapter *adpt)
290 {
291 	struct net_device *netdev = adpt->netdev;
292 	u32 mac;
293 
294 	mac = readl(adpt->base + EMAC_MAC_CTRL);
295 	mac &= ~(VLAN_STRIP | PROM_MODE | MULTI_ALL | MAC_LP_EN);
296 
297 	if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX)
298 		mac |= VLAN_STRIP;
299 
300 	if (netdev->flags & IFF_PROMISC)
301 		mac |= PROM_MODE;
302 
303 	if (netdev->flags & IFF_ALLMULTI)
304 		mac |= MULTI_ALL;
305 
306 	writel(mac, adpt->base + EMAC_MAC_CTRL);
307 }
308 
309 /* Config descriptor rings */
310 static void emac_mac_dma_rings_config(struct emac_adapter *adpt)
311 {
312 	/* TPD (Transmit Packet Descriptor) */
313 	writel(upper_32_bits(adpt->tx_q.tpd.dma_addr),
314 	       adpt->base + EMAC_DESC_CTRL_1);
315 
316 	writel(lower_32_bits(adpt->tx_q.tpd.dma_addr),
317 	       adpt->base + EMAC_DESC_CTRL_8);
318 
319 	writel(adpt->tx_q.tpd.count & TPD_RING_SIZE_BMSK,
320 	       adpt->base + EMAC_DESC_CTRL_9);
321 
322 	/* RFD (Receive Free Descriptor) & RRD (Receive Return Descriptor) */
323 	writel(upper_32_bits(adpt->rx_q.rfd.dma_addr),
324 	       adpt->base + EMAC_DESC_CTRL_0);
325 
326 	writel(lower_32_bits(adpt->rx_q.rfd.dma_addr),
327 	       adpt->base + EMAC_DESC_CTRL_2);
328 	writel(lower_32_bits(adpt->rx_q.rrd.dma_addr),
329 	       adpt->base + EMAC_DESC_CTRL_5);
330 
331 	writel(adpt->rx_q.rfd.count & RFD_RING_SIZE_BMSK,
332 	       adpt->base + EMAC_DESC_CTRL_3);
333 	writel(adpt->rx_q.rrd.count & RRD_RING_SIZE_BMSK,
334 	       adpt->base + EMAC_DESC_CTRL_6);
335 
336 	writel(adpt->rxbuf_size & RX_BUFFER_SIZE_BMSK,
337 	       adpt->base + EMAC_DESC_CTRL_4);
338 
339 	writel(0, adpt->base + EMAC_DESC_CTRL_11);
340 
341 	/* Load all of the base addresses above and ensure that triggering HW to
342 	 * read ring pointers is flushed
343 	 */
344 	writel(1, adpt->base + EMAC_INTER_SRAM_PART9);
345 }
346 
347 /* Config transmit parameters */
348 static void emac_mac_tx_config(struct emac_adapter *adpt)
349 {
350 	u32 val;
351 
352 	writel((EMAC_MAX_TX_OFFLOAD_THRESH >> 3) &
353 	       JUMBO_TASK_OFFLOAD_THRESHOLD_BMSK, adpt->base + EMAC_TXQ_CTRL_1);
354 
355 	val = (adpt->tpd_burst << NUM_TPD_BURST_PREF_SHFT) &
356 	       NUM_TPD_BURST_PREF_BMSK;
357 
358 	val |= TXQ_MODE | LS_8023_SP;
359 	val |= (0x0100 << NUM_TXF_BURST_PREF_SHFT) &
360 		NUM_TXF_BURST_PREF_BMSK;
361 
362 	writel(val, adpt->base + EMAC_TXQ_CTRL_0);
363 	emac_reg_update32(adpt->base + EMAC_TXQ_CTRL_2,
364 			  (TXF_HWM_BMSK | TXF_LWM_BMSK), 0);
365 }
366 
367 /* Config receive parameters */
368 static void emac_mac_rx_config(struct emac_adapter *adpt)
369 {
370 	u32 val;
371 
372 	val = (adpt->rfd_burst << NUM_RFD_BURST_PREF_SHFT) &
373 	       NUM_RFD_BURST_PREF_BMSK;
374 	val |= (SP_IPV6 | CUT_THRU_EN);
375 
376 	writel(val, adpt->base + EMAC_RXQ_CTRL_0);
377 
378 	val = readl(adpt->base + EMAC_RXQ_CTRL_1);
379 	val &= ~(JUMBO_1KAH_BMSK | RFD_PREF_LOW_THRESHOLD_BMSK |
380 		 RFD_PREF_UP_THRESHOLD_BMSK);
381 	val |= (JUMBO_1KAH << JUMBO_1KAH_SHFT) |
382 		(RFD_PREF_LOW_TH << RFD_PREF_LOW_THRESHOLD_SHFT) |
383 		(RFD_PREF_UP_TH  << RFD_PREF_UP_THRESHOLD_SHFT);
384 	writel(val, adpt->base + EMAC_RXQ_CTRL_1);
385 
386 	val = readl(adpt->base + EMAC_RXQ_CTRL_2);
387 	val &= ~(RXF_DOF_THRESHOLD_BMSK | RXF_UOF_THRESHOLD_BMSK);
388 	val |= (RXF_DOF_THRESFHOLD  << RXF_DOF_THRESHOLD_SHFT) |
389 		(RXF_UOF_THRESFHOLD << RXF_UOF_THRESHOLD_SHFT);
390 	writel(val, adpt->base + EMAC_RXQ_CTRL_2);
391 
392 	val = readl(adpt->base + EMAC_RXQ_CTRL_3);
393 	val &= ~(RXD_TIMER_BMSK | RXD_THRESHOLD_BMSK);
394 	val |= RXD_TH << RXD_THRESHOLD_SHFT;
395 	writel(val, adpt->base + EMAC_RXQ_CTRL_3);
396 }
397 
398 /* Config dma */
399 static void emac_mac_dma_config(struct emac_adapter *adpt)
400 {
401 	u32 dma_ctrl = DMAR_REQ_PRI;
402 
403 	switch (adpt->dma_order) {
404 	case emac_dma_ord_in:
405 		dma_ctrl |= IN_ORDER_MODE;
406 		break;
407 	case emac_dma_ord_enh:
408 		dma_ctrl |= ENH_ORDER_MODE;
409 		break;
410 	case emac_dma_ord_out:
411 		dma_ctrl |= OUT_ORDER_MODE;
412 		break;
413 	default:
414 		break;
415 	}
416 
417 	dma_ctrl |= (((u32)adpt->dmar_block) << REGRDBLEN_SHFT) &
418 						REGRDBLEN_BMSK;
419 	dma_ctrl |= (((u32)adpt->dmaw_block) << REGWRBLEN_SHFT) &
420 						REGWRBLEN_BMSK;
421 	dma_ctrl |= (((u32)adpt->dmar_dly_cnt) << DMAR_DLY_CNT_SHFT) &
422 						DMAR_DLY_CNT_BMSK;
423 	dma_ctrl |= (((u32)adpt->dmaw_dly_cnt) << DMAW_DLY_CNT_SHFT) &
424 						DMAW_DLY_CNT_BMSK;
425 
426 	/* config DMA and ensure that configuration is flushed to HW */
427 	writel(dma_ctrl, adpt->base + EMAC_DMA_CTRL);
428 }
429 
430 /* set MAC address */
431 static void emac_set_mac_address(struct emac_adapter *adpt, u8 *addr)
432 {
433 	u32 sta;
434 
435 	/* for example: 00-A0-C6-11-22-33
436 	 * 0<-->C6112233, 1<-->00A0.
437 	 */
438 
439 	/* low 32bit word */
440 	sta = (((u32)addr[2]) << 24) | (((u32)addr[3]) << 16) |
441 	      (((u32)addr[4]) << 8)  | (((u32)addr[5]));
442 	writel(sta, adpt->base + EMAC_MAC_STA_ADDR0);
443 
444 	/* hight 32bit word */
445 	sta = (((u32)addr[0]) << 8) | (u32)addr[1];
446 	writel(sta, adpt->base + EMAC_MAC_STA_ADDR1);
447 }
448 
449 static void emac_mac_config(struct emac_adapter *adpt)
450 {
451 	struct net_device *netdev = adpt->netdev;
452 	unsigned int max_frame;
453 	u32 val;
454 
455 	emac_set_mac_address(adpt, netdev->dev_addr);
456 
457 	max_frame = netdev->mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
458 	adpt->rxbuf_size = netdev->mtu > EMAC_DEF_RX_BUF_SIZE ?
459 		ALIGN(max_frame, 8) : EMAC_DEF_RX_BUF_SIZE;
460 
461 	emac_mac_dma_rings_config(adpt);
462 
463 	writel(netdev->mtu + ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN,
464 	       adpt->base + EMAC_MAX_FRAM_LEN_CTRL);
465 
466 	emac_mac_tx_config(adpt);
467 	emac_mac_rx_config(adpt);
468 	emac_mac_dma_config(adpt);
469 
470 	val = readl(adpt->base + EMAC_AXI_MAST_CTRL);
471 	val &= ~(DATA_BYTE_SWAP | MAX_BOUND);
472 	val |= MAX_BTYPE;
473 	writel(val, adpt->base + EMAC_AXI_MAST_CTRL);
474 	writel(0, adpt->base + EMAC_CLK_GATE_CTRL);
475 	writel(RX_UNCPL_INT_EN, adpt->base + EMAC_MISC_CTRL);
476 }
477 
478 void emac_mac_reset(struct emac_adapter *adpt)
479 {
480 	emac_mac_stop(adpt);
481 
482 	emac_reg_update32(adpt->base + EMAC_DMA_MAS_CTRL, 0, SOFT_RST);
483 	usleep_range(100, 150); /* reset may take up to 100usec */
484 
485 	/* interrupt clear-on-read */
486 	emac_reg_update32(adpt->base + EMAC_DMA_MAS_CTRL, 0, INT_RD_CLR_EN);
487 }
488 
489 static void emac_mac_start(struct emac_adapter *adpt)
490 {
491 	struct phy_device *phydev = adpt->phydev;
492 	u32 mac, csr1;
493 
494 	/* enable tx queue */
495 	emac_reg_update32(adpt->base + EMAC_TXQ_CTRL_0, 0, TXQ_EN);
496 
497 	/* enable rx queue */
498 	emac_reg_update32(adpt->base + EMAC_RXQ_CTRL_0, 0, RXQ_EN);
499 
500 	/* enable mac control */
501 	mac = readl(adpt->base + EMAC_MAC_CTRL);
502 	csr1 = readl(adpt->csr + EMAC_EMAC_WRAPPER_CSR1);
503 
504 	mac |= TXEN | RXEN;     /* enable RX/TX */
505 
506 	/* Configure MAC flow control. If set to automatic, then match
507 	 * whatever the PHY does. Otherwise, enable or disable it, depending
508 	 * on what the user configured via ethtool.
509 	 */
510 	mac &= ~(RXFC | TXFC);
511 
512 	if (adpt->automatic) {
513 		/* If it's set to automatic, then update our local values */
514 		adpt->rx_flow_control = phydev->pause;
515 		adpt->tx_flow_control = phydev->pause != phydev->asym_pause;
516 	}
517 	mac |= adpt->rx_flow_control ? RXFC : 0;
518 	mac |= adpt->tx_flow_control ? TXFC : 0;
519 
520 	/* setup link speed */
521 	mac &= ~SPEED_MASK;
522 	if (phydev->speed == SPEED_1000) {
523 		mac |= SPEED(2);
524 		csr1 |= FREQ_MODE;
525 	} else {
526 		mac |= SPEED(1);
527 		csr1 &= ~FREQ_MODE;
528 	}
529 
530 	if (phydev->duplex == DUPLEX_FULL)
531 		mac |= FULLD;
532 	else
533 		mac &= ~FULLD;
534 
535 	/* other parameters */
536 	mac |= (CRCE | PCRCE);
537 	mac |= ((adpt->preamble << PRLEN_SHFT) & PRLEN_BMSK);
538 	mac |= BROAD_EN;
539 	mac |= FLCHK;
540 	mac &= ~RX_CHKSUM_EN;
541 	mac &= ~(HUGEN | VLAN_STRIP | TPAUSE | SIMR | HUGE | MULTI_ALL |
542 		 DEBUG_MODE | SINGLE_PAUSE_MODE);
543 
544 	/* Enable single-pause-frame mode if requested.
545 	 *
546 	 * If enabled, the EMAC will send a single pause frame when the RX
547 	 * queue is full.  This normally leads to packet loss because
548 	 * the pause frame disables the remote MAC only for 33ms (the quanta),
549 	 * and then the remote MAC continues sending packets even though
550 	 * the RX queue is still full.
551 	 *
552 	 * If disabled, the EMAC sends a pause frame every 31ms until the RX
553 	 * queue is no longer full.  Normally, this is the preferred
554 	 * method of operation.  However, when the system is hung (e.g.
555 	 * cores are halted), the EMAC interrupt handler is never called
556 	 * and so the RX queue fills up quickly and stays full.  The resuling
557 	 * non-stop "flood" of pause frames sometimes has the effect of
558 	 * disabling nearby switches.  In some cases, other nearby switches
559 	 * are also affected, shutting down the entire network.
560 	 *
561 	 * The user can enable or disable single-pause-frame mode
562 	 * via ethtool.
563 	 */
564 	mac |= adpt->single_pause_mode ? SINGLE_PAUSE_MODE : 0;
565 
566 	writel_relaxed(csr1, adpt->csr + EMAC_EMAC_WRAPPER_CSR1);
567 
568 	writel_relaxed(mac, adpt->base + EMAC_MAC_CTRL);
569 
570 	/* enable interrupt read clear, low power sleep mode and
571 	 * the irq moderators
572 	 */
573 
574 	writel_relaxed(adpt->irq_mod, adpt->base + EMAC_IRQ_MOD_TIM_INIT);
575 	writel_relaxed(INT_RD_CLR_EN | LPW_MODE | IRQ_MODERATOR_EN |
576 			IRQ_MODERATOR2_EN, adpt->base + EMAC_DMA_MAS_CTRL);
577 
578 	emac_mac_mode_config(adpt);
579 
580 	emac_reg_update32(adpt->base + EMAC_ATHR_HEADER_CTRL,
581 			  (HEADER_ENABLE | HEADER_CNT_EN), 0);
582 }
583 
584 void emac_mac_stop(struct emac_adapter *adpt)
585 {
586 	emac_reg_update32(adpt->base + EMAC_RXQ_CTRL_0, RXQ_EN, 0);
587 	emac_reg_update32(adpt->base + EMAC_TXQ_CTRL_0, TXQ_EN, 0);
588 	emac_reg_update32(adpt->base + EMAC_MAC_CTRL, TXEN | RXEN, 0);
589 	usleep_range(1000, 1050); /* stopping mac may take upto 1msec */
590 }
591 
592 /* Free all descriptors of given transmit queue */
593 static void emac_tx_q_descs_free(struct emac_adapter *adpt)
594 {
595 	struct emac_tx_queue *tx_q = &adpt->tx_q;
596 	unsigned int i;
597 	size_t size;
598 
599 	/* ring already cleared, nothing to do */
600 	if (!tx_q->tpd.tpbuff)
601 		return;
602 
603 	for (i = 0; i < tx_q->tpd.count; i++) {
604 		struct emac_buffer *tpbuf = GET_TPD_BUFFER(tx_q, i);
605 
606 		if (tpbuf->dma_addr) {
607 			dma_unmap_single(adpt->netdev->dev.parent,
608 					 tpbuf->dma_addr, tpbuf->length,
609 					 DMA_TO_DEVICE);
610 			tpbuf->dma_addr = 0;
611 		}
612 		if (tpbuf->skb) {
613 			dev_kfree_skb_any(tpbuf->skb);
614 			tpbuf->skb = NULL;
615 		}
616 	}
617 
618 	size = sizeof(struct emac_buffer) * tx_q->tpd.count;
619 	memset(tx_q->tpd.tpbuff, 0, size);
620 
621 	/* clear the descriptor ring */
622 	memset(tx_q->tpd.v_addr, 0, tx_q->tpd.size);
623 
624 	tx_q->tpd.consume_idx = 0;
625 	tx_q->tpd.produce_idx = 0;
626 }
627 
628 /* Free all descriptors of given receive queue */
629 static void emac_rx_q_free_descs(struct emac_adapter *adpt)
630 {
631 	struct device *dev = adpt->netdev->dev.parent;
632 	struct emac_rx_queue *rx_q = &adpt->rx_q;
633 	unsigned int i;
634 	size_t size;
635 
636 	/* ring already cleared, nothing to do */
637 	if (!rx_q->rfd.rfbuff)
638 		return;
639 
640 	for (i = 0; i < rx_q->rfd.count; i++) {
641 		struct emac_buffer *rfbuf = GET_RFD_BUFFER(rx_q, i);
642 
643 		if (rfbuf->dma_addr) {
644 			dma_unmap_single(dev, rfbuf->dma_addr, rfbuf->length,
645 					 DMA_FROM_DEVICE);
646 			rfbuf->dma_addr = 0;
647 		}
648 		if (rfbuf->skb) {
649 			dev_kfree_skb(rfbuf->skb);
650 			rfbuf->skb = NULL;
651 		}
652 	}
653 
654 	size =  sizeof(struct emac_buffer) * rx_q->rfd.count;
655 	memset(rx_q->rfd.rfbuff, 0, size);
656 
657 	/* clear the descriptor rings */
658 	memset(rx_q->rrd.v_addr, 0, rx_q->rrd.size);
659 	rx_q->rrd.produce_idx = 0;
660 	rx_q->rrd.consume_idx = 0;
661 
662 	memset(rx_q->rfd.v_addr, 0, rx_q->rfd.size);
663 	rx_q->rfd.produce_idx = 0;
664 	rx_q->rfd.consume_idx = 0;
665 }
666 
667 /* Free all buffers associated with given transmit queue */
668 static void emac_tx_q_bufs_free(struct emac_adapter *adpt)
669 {
670 	struct emac_tx_queue *tx_q = &adpt->tx_q;
671 
672 	emac_tx_q_descs_free(adpt);
673 
674 	kfree(tx_q->tpd.tpbuff);
675 	tx_q->tpd.tpbuff = NULL;
676 	tx_q->tpd.v_addr = NULL;
677 	tx_q->tpd.dma_addr = 0;
678 	tx_q->tpd.size = 0;
679 }
680 
681 /* Allocate TX descriptor ring for the given transmit queue */
682 static int emac_tx_q_desc_alloc(struct emac_adapter *adpt,
683 				struct emac_tx_queue *tx_q)
684 {
685 	struct emac_ring_header *ring_header = &adpt->ring_header;
686 	int node = dev_to_node(adpt->netdev->dev.parent);
687 	size_t size;
688 
689 	size = sizeof(struct emac_buffer) * tx_q->tpd.count;
690 	tx_q->tpd.tpbuff = kzalloc_node(size, GFP_KERNEL, node);
691 	if (!tx_q->tpd.tpbuff)
692 		return -ENOMEM;
693 
694 	tx_q->tpd.size = tx_q->tpd.count * (adpt->tpd_size * 4);
695 	tx_q->tpd.dma_addr = ring_header->dma_addr + ring_header->used;
696 	tx_q->tpd.v_addr = ring_header->v_addr + ring_header->used;
697 	ring_header->used += ALIGN(tx_q->tpd.size, 8);
698 	tx_q->tpd.produce_idx = 0;
699 	tx_q->tpd.consume_idx = 0;
700 
701 	return 0;
702 }
703 
704 /* Free all buffers associated with given transmit queue */
705 static void emac_rx_q_bufs_free(struct emac_adapter *adpt)
706 {
707 	struct emac_rx_queue *rx_q = &adpt->rx_q;
708 
709 	emac_rx_q_free_descs(adpt);
710 
711 	kfree(rx_q->rfd.rfbuff);
712 	rx_q->rfd.rfbuff   = NULL;
713 
714 	rx_q->rfd.v_addr   = NULL;
715 	rx_q->rfd.dma_addr = 0;
716 	rx_q->rfd.size     = 0;
717 
718 	rx_q->rrd.v_addr   = NULL;
719 	rx_q->rrd.dma_addr = 0;
720 	rx_q->rrd.size     = 0;
721 }
722 
723 /* Allocate RX descriptor rings for the given receive queue */
724 static int emac_rx_descs_alloc(struct emac_adapter *adpt)
725 {
726 	struct emac_ring_header *ring_header = &adpt->ring_header;
727 	int node = dev_to_node(adpt->netdev->dev.parent);
728 	struct emac_rx_queue *rx_q = &adpt->rx_q;
729 	size_t size;
730 
731 	size = sizeof(struct emac_buffer) * rx_q->rfd.count;
732 	rx_q->rfd.rfbuff = kzalloc_node(size, GFP_KERNEL, node);
733 	if (!rx_q->rfd.rfbuff)
734 		return -ENOMEM;
735 
736 	rx_q->rrd.size = rx_q->rrd.count * (adpt->rrd_size * 4);
737 	rx_q->rfd.size = rx_q->rfd.count * (adpt->rfd_size * 4);
738 
739 	rx_q->rrd.dma_addr = ring_header->dma_addr + ring_header->used;
740 	rx_q->rrd.v_addr   = ring_header->v_addr + ring_header->used;
741 	ring_header->used += ALIGN(rx_q->rrd.size, 8);
742 
743 	rx_q->rfd.dma_addr = ring_header->dma_addr + ring_header->used;
744 	rx_q->rfd.v_addr   = ring_header->v_addr + ring_header->used;
745 	ring_header->used += ALIGN(rx_q->rfd.size, 8);
746 
747 	rx_q->rrd.produce_idx = 0;
748 	rx_q->rrd.consume_idx = 0;
749 
750 	rx_q->rfd.produce_idx = 0;
751 	rx_q->rfd.consume_idx = 0;
752 
753 	return 0;
754 }
755 
756 /* Allocate all TX and RX descriptor rings */
757 int emac_mac_rx_tx_rings_alloc_all(struct emac_adapter *adpt)
758 {
759 	struct emac_ring_header *ring_header = &adpt->ring_header;
760 	struct device *dev = adpt->netdev->dev.parent;
761 	unsigned int num_tx_descs = adpt->tx_desc_cnt;
762 	unsigned int num_rx_descs = adpt->rx_desc_cnt;
763 	int ret;
764 
765 	adpt->tx_q.tpd.count = adpt->tx_desc_cnt;
766 
767 	adpt->rx_q.rrd.count = adpt->rx_desc_cnt;
768 	adpt->rx_q.rfd.count = adpt->rx_desc_cnt;
769 
770 	/* Ring DMA buffer. Each ring may need up to 8 bytes for alignment,
771 	 * hence the additional padding bytes are allocated.
772 	 */
773 	ring_header->size = num_tx_descs * (adpt->tpd_size * 4) +
774 			    num_rx_descs * (adpt->rfd_size * 4) +
775 			    num_rx_descs * (adpt->rrd_size * 4) +
776 			    8 + 2 * 8; /* 8 byte per one Tx and two Rx rings */
777 
778 	ring_header->used = 0;
779 	ring_header->v_addr = dma_zalloc_coherent(dev, ring_header->size,
780 						 &ring_header->dma_addr,
781 						 GFP_KERNEL);
782 	if (!ring_header->v_addr)
783 		return -ENOMEM;
784 
785 	ring_header->used = ALIGN(ring_header->dma_addr, 8) -
786 							ring_header->dma_addr;
787 
788 	ret = emac_tx_q_desc_alloc(adpt, &adpt->tx_q);
789 	if (ret) {
790 		netdev_err(adpt->netdev, "error: Tx Queue alloc failed\n");
791 		goto err_alloc_tx;
792 	}
793 
794 	ret = emac_rx_descs_alloc(adpt);
795 	if (ret) {
796 		netdev_err(adpt->netdev, "error: Rx Queue alloc failed\n");
797 		goto err_alloc_rx;
798 	}
799 
800 	return 0;
801 
802 err_alloc_rx:
803 	emac_tx_q_bufs_free(adpt);
804 err_alloc_tx:
805 	dma_free_coherent(dev, ring_header->size,
806 			  ring_header->v_addr, ring_header->dma_addr);
807 
808 	ring_header->v_addr   = NULL;
809 	ring_header->dma_addr = 0;
810 	ring_header->size     = 0;
811 	ring_header->used     = 0;
812 
813 	return ret;
814 }
815 
816 /* Free all TX and RX descriptor rings */
817 void emac_mac_rx_tx_rings_free_all(struct emac_adapter *adpt)
818 {
819 	struct emac_ring_header *ring_header = &adpt->ring_header;
820 	struct device *dev = adpt->netdev->dev.parent;
821 
822 	emac_tx_q_bufs_free(adpt);
823 	emac_rx_q_bufs_free(adpt);
824 
825 	dma_free_coherent(dev, ring_header->size,
826 			  ring_header->v_addr, ring_header->dma_addr);
827 
828 	ring_header->v_addr   = NULL;
829 	ring_header->dma_addr = 0;
830 	ring_header->size     = 0;
831 	ring_header->used     = 0;
832 }
833 
834 /* Initialize descriptor rings */
835 static void emac_mac_rx_tx_ring_reset_all(struct emac_adapter *adpt)
836 {
837 	unsigned int i;
838 
839 	adpt->tx_q.tpd.produce_idx = 0;
840 	adpt->tx_q.tpd.consume_idx = 0;
841 	for (i = 0; i < adpt->tx_q.tpd.count; i++)
842 		adpt->tx_q.tpd.tpbuff[i].dma_addr = 0;
843 
844 	adpt->rx_q.rrd.produce_idx = 0;
845 	adpt->rx_q.rrd.consume_idx = 0;
846 	adpt->rx_q.rfd.produce_idx = 0;
847 	adpt->rx_q.rfd.consume_idx = 0;
848 	for (i = 0; i < adpt->rx_q.rfd.count; i++)
849 		adpt->rx_q.rfd.rfbuff[i].dma_addr = 0;
850 }
851 
852 /* Produce new receive free descriptor */
853 static void emac_mac_rx_rfd_create(struct emac_adapter *adpt,
854 				   struct emac_rx_queue *rx_q,
855 				   dma_addr_t addr)
856 {
857 	u32 *hw_rfd = EMAC_RFD(rx_q, adpt->rfd_size, rx_q->rfd.produce_idx);
858 
859 	*(hw_rfd++) = lower_32_bits(addr);
860 	*hw_rfd = upper_32_bits(addr);
861 
862 	if (++rx_q->rfd.produce_idx == rx_q->rfd.count)
863 		rx_q->rfd.produce_idx = 0;
864 }
865 
866 /* Fill up receive queue's RFD with preallocated receive buffers */
867 static void emac_mac_rx_descs_refill(struct emac_adapter *adpt,
868 				    struct emac_rx_queue *rx_q)
869 {
870 	struct emac_buffer *curr_rxbuf;
871 	struct emac_buffer *next_rxbuf;
872 	unsigned int count = 0;
873 	u32 next_produce_idx;
874 
875 	next_produce_idx = rx_q->rfd.produce_idx + 1;
876 	if (next_produce_idx == rx_q->rfd.count)
877 		next_produce_idx = 0;
878 
879 	curr_rxbuf = GET_RFD_BUFFER(rx_q, rx_q->rfd.produce_idx);
880 	next_rxbuf = GET_RFD_BUFFER(rx_q, next_produce_idx);
881 
882 	/* this always has a blank rx_buffer*/
883 	while (!next_rxbuf->dma_addr) {
884 		struct sk_buff *skb;
885 		int ret;
886 
887 		skb = netdev_alloc_skb_ip_align(adpt->netdev, adpt->rxbuf_size);
888 		if (!skb)
889 			break;
890 
891 		curr_rxbuf->dma_addr =
892 			dma_map_single(adpt->netdev->dev.parent, skb->data,
893 				       adpt->rxbuf_size, DMA_FROM_DEVICE);
894 
895 		ret = dma_mapping_error(adpt->netdev->dev.parent,
896 					curr_rxbuf->dma_addr);
897 		if (ret) {
898 			dev_kfree_skb(skb);
899 			break;
900 		}
901 		curr_rxbuf->skb = skb;
902 		curr_rxbuf->length = adpt->rxbuf_size;
903 
904 		emac_mac_rx_rfd_create(adpt, rx_q, curr_rxbuf->dma_addr);
905 		next_produce_idx = rx_q->rfd.produce_idx + 1;
906 		if (next_produce_idx == rx_q->rfd.count)
907 			next_produce_idx = 0;
908 
909 		curr_rxbuf = GET_RFD_BUFFER(rx_q, rx_q->rfd.produce_idx);
910 		next_rxbuf = GET_RFD_BUFFER(rx_q, next_produce_idx);
911 		count++;
912 	}
913 
914 	if (count) {
915 		u32 prod_idx = (rx_q->rfd.produce_idx << rx_q->produce_shift) &
916 				rx_q->produce_mask;
917 		emac_reg_update32(adpt->base + rx_q->produce_reg,
918 				  rx_q->produce_mask, prod_idx);
919 	}
920 }
921 
922 static void emac_adjust_link(struct net_device *netdev)
923 {
924 	struct emac_adapter *adpt = netdev_priv(netdev);
925 	struct phy_device *phydev = netdev->phydev;
926 
927 	if (phydev->link) {
928 		emac_mac_start(adpt);
929 		emac_sgmii_link_change(adpt, true);
930 	} else {
931 		emac_sgmii_link_change(adpt, false);
932 		emac_mac_stop(adpt);
933 	}
934 
935 	phy_print_status(phydev);
936 }
937 
938 /* Bringup the interface/HW */
939 int emac_mac_up(struct emac_adapter *adpt)
940 {
941 	struct net_device *netdev = adpt->netdev;
942 	int ret;
943 
944 	emac_mac_rx_tx_ring_reset_all(adpt);
945 	emac_mac_config(adpt);
946 	emac_mac_rx_descs_refill(adpt, &adpt->rx_q);
947 
948 	adpt->phydev->irq = PHY_POLL;
949 	ret = phy_connect_direct(netdev, adpt->phydev, emac_adjust_link,
950 				 PHY_INTERFACE_MODE_SGMII);
951 	if (ret) {
952 		netdev_err(adpt->netdev, "could not connect phy\n");
953 		return ret;
954 	}
955 
956 	phy_attached_print(adpt->phydev, NULL);
957 
958 	/* enable mac irq */
959 	writel((u32)~DIS_INT, adpt->base + EMAC_INT_STATUS);
960 	writel(adpt->irq.mask, adpt->base + EMAC_INT_MASK);
961 
962 	phy_start(adpt->phydev);
963 
964 	napi_enable(&adpt->rx_q.napi);
965 	netif_start_queue(netdev);
966 
967 	return 0;
968 }
969 
970 /* Bring down the interface/HW */
971 void emac_mac_down(struct emac_adapter *adpt)
972 {
973 	struct net_device *netdev = adpt->netdev;
974 
975 	netif_stop_queue(netdev);
976 	napi_disable(&adpt->rx_q.napi);
977 
978 	phy_stop(adpt->phydev);
979 
980 	/* Interrupts must be disabled before the PHY is disconnected, to
981 	 * avoid a race condition where adjust_link is null when we get
982 	 * an interrupt.
983 	 */
984 	writel(DIS_INT, adpt->base + EMAC_INT_STATUS);
985 	writel(0, adpt->base + EMAC_INT_MASK);
986 	synchronize_irq(adpt->irq.irq);
987 
988 	phy_disconnect(adpt->phydev);
989 
990 	emac_mac_reset(adpt);
991 
992 	emac_tx_q_descs_free(adpt);
993 	netdev_reset_queue(adpt->netdev);
994 	emac_rx_q_free_descs(adpt);
995 }
996 
997 /* Consume next received packet descriptor */
998 static bool emac_rx_process_rrd(struct emac_adapter *adpt,
999 				struct emac_rx_queue *rx_q,
1000 				struct emac_rrd *rrd)
1001 {
1002 	u32 *hw_rrd = EMAC_RRD(rx_q, adpt->rrd_size, rx_q->rrd.consume_idx);
1003 
1004 	rrd->word[3] = *(hw_rrd + 3);
1005 
1006 	if (!RRD_UPDT(rrd))
1007 		return false;
1008 
1009 	rrd->word[4] = 0;
1010 	rrd->word[5] = 0;
1011 
1012 	rrd->word[0] = *(hw_rrd++);
1013 	rrd->word[1] = *(hw_rrd++);
1014 	rrd->word[2] = *(hw_rrd++);
1015 
1016 	if (unlikely(RRD_NOR(rrd) != 1)) {
1017 		netdev_err(adpt->netdev,
1018 			   "error: multi-RFD not support yet! nor:%lu\n",
1019 			   RRD_NOR(rrd));
1020 	}
1021 
1022 	/* mark rrd as processed */
1023 	RRD_UPDT_SET(rrd, 0);
1024 	*hw_rrd = rrd->word[3];
1025 
1026 	if (++rx_q->rrd.consume_idx == rx_q->rrd.count)
1027 		rx_q->rrd.consume_idx = 0;
1028 
1029 	return true;
1030 }
1031 
1032 /* Produce new transmit descriptor */
1033 static void emac_tx_tpd_create(struct emac_adapter *adpt,
1034 			       struct emac_tx_queue *tx_q, struct emac_tpd *tpd)
1035 {
1036 	u32 *hw_tpd;
1037 
1038 	tx_q->tpd.last_produce_idx = tx_q->tpd.produce_idx;
1039 	hw_tpd = EMAC_TPD(tx_q, adpt->tpd_size, tx_q->tpd.produce_idx);
1040 
1041 	if (++tx_q->tpd.produce_idx == tx_q->tpd.count)
1042 		tx_q->tpd.produce_idx = 0;
1043 
1044 	*(hw_tpd++) = tpd->word[0];
1045 	*(hw_tpd++) = tpd->word[1];
1046 	*(hw_tpd++) = tpd->word[2];
1047 	*hw_tpd = tpd->word[3];
1048 }
1049 
1050 /* Mark the last transmit descriptor as such (for the transmit packet) */
1051 static void emac_tx_tpd_mark_last(struct emac_adapter *adpt,
1052 				  struct emac_tx_queue *tx_q)
1053 {
1054 	u32 *hw_tpd =
1055 		EMAC_TPD(tx_q, adpt->tpd_size, tx_q->tpd.last_produce_idx);
1056 	u32 tmp_tpd;
1057 
1058 	tmp_tpd = *(hw_tpd + 1);
1059 	tmp_tpd |= EMAC_TPD_LAST_FRAGMENT;
1060 	*(hw_tpd + 1) = tmp_tpd;
1061 }
1062 
1063 static void emac_rx_rfd_clean(struct emac_rx_queue *rx_q, struct emac_rrd *rrd)
1064 {
1065 	struct emac_buffer *rfbuf = rx_q->rfd.rfbuff;
1066 	u32 consume_idx = RRD_SI(rrd);
1067 	unsigned int i;
1068 
1069 	for (i = 0; i < RRD_NOR(rrd); i++) {
1070 		rfbuf[consume_idx].skb = NULL;
1071 		if (++consume_idx == rx_q->rfd.count)
1072 			consume_idx = 0;
1073 	}
1074 
1075 	rx_q->rfd.consume_idx = consume_idx;
1076 	rx_q->rfd.process_idx = consume_idx;
1077 }
1078 
1079 /* Push the received skb to upper layers */
1080 static void emac_receive_skb(struct emac_rx_queue *rx_q,
1081 			     struct sk_buff *skb,
1082 			     u16 vlan_tag, bool vlan_flag)
1083 {
1084 	if (vlan_flag) {
1085 		u16 vlan;
1086 
1087 		EMAC_TAG_TO_VLAN(vlan_tag, vlan);
1088 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan);
1089 	}
1090 
1091 	napi_gro_receive(&rx_q->napi, skb);
1092 }
1093 
1094 /* Process receive event */
1095 void emac_mac_rx_process(struct emac_adapter *adpt, struct emac_rx_queue *rx_q,
1096 			 int *num_pkts, int max_pkts)
1097 {
1098 	u32 proc_idx, hw_consume_idx, num_consume_pkts;
1099 	struct net_device *netdev  = adpt->netdev;
1100 	struct emac_buffer *rfbuf;
1101 	unsigned int count = 0;
1102 	struct emac_rrd rrd;
1103 	struct sk_buff *skb;
1104 	u32 reg;
1105 
1106 	reg = readl_relaxed(adpt->base + rx_q->consume_reg);
1107 
1108 	hw_consume_idx = (reg & rx_q->consume_mask) >> rx_q->consume_shift;
1109 	num_consume_pkts = (hw_consume_idx >= rx_q->rrd.consume_idx) ?
1110 		(hw_consume_idx -  rx_q->rrd.consume_idx) :
1111 		(hw_consume_idx + rx_q->rrd.count - rx_q->rrd.consume_idx);
1112 
1113 	do {
1114 		if (!num_consume_pkts)
1115 			break;
1116 
1117 		if (!emac_rx_process_rrd(adpt, rx_q, &rrd))
1118 			break;
1119 
1120 		if (likely(RRD_NOR(&rrd) == 1)) {
1121 			/* good receive */
1122 			rfbuf = GET_RFD_BUFFER(rx_q, RRD_SI(&rrd));
1123 			dma_unmap_single(adpt->netdev->dev.parent,
1124 					 rfbuf->dma_addr, rfbuf->length,
1125 					 DMA_FROM_DEVICE);
1126 			rfbuf->dma_addr = 0;
1127 			skb = rfbuf->skb;
1128 		} else {
1129 			netdev_err(adpt->netdev,
1130 				   "error: multi-RFD not support yet!\n");
1131 			break;
1132 		}
1133 		emac_rx_rfd_clean(rx_q, &rrd);
1134 		num_consume_pkts--;
1135 		count++;
1136 
1137 		/* Due to a HW issue in L4 check sum detection (UDP/TCP frags
1138 		 * with DF set are marked as error), drop packets based on the
1139 		 * error mask rather than the summary bit (ignoring L4F errors)
1140 		 */
1141 		if (rrd.word[EMAC_RRD_STATS_DW_IDX] & EMAC_RRD_ERROR) {
1142 			netif_dbg(adpt, rx_status, adpt->netdev,
1143 				  "Drop error packet[RRD: 0x%x:0x%x:0x%x:0x%x]\n",
1144 				  rrd.word[0], rrd.word[1],
1145 				  rrd.word[2], rrd.word[3]);
1146 
1147 			dev_kfree_skb(skb);
1148 			continue;
1149 		}
1150 
1151 		skb_put(skb, RRD_PKT_SIZE(&rrd) - ETH_FCS_LEN);
1152 		skb->dev = netdev;
1153 		skb->protocol = eth_type_trans(skb, skb->dev);
1154 		if (netdev->features & NETIF_F_RXCSUM)
1155 			skb->ip_summed = RRD_L4F(&rrd) ?
1156 					  CHECKSUM_NONE : CHECKSUM_UNNECESSARY;
1157 		else
1158 			skb_checksum_none_assert(skb);
1159 
1160 		emac_receive_skb(rx_q, skb, (u16)RRD_CVALN_TAG(&rrd),
1161 				 (bool)RRD_CVTAG(&rrd));
1162 
1163 		(*num_pkts)++;
1164 	} while (*num_pkts < max_pkts);
1165 
1166 	if (count) {
1167 		proc_idx = (rx_q->rfd.process_idx << rx_q->process_shft) &
1168 				rx_q->process_mask;
1169 		emac_reg_update32(adpt->base + rx_q->process_reg,
1170 				  rx_q->process_mask, proc_idx);
1171 		emac_mac_rx_descs_refill(adpt, rx_q);
1172 	}
1173 }
1174 
1175 /* get the number of free transmit descriptors */
1176 static unsigned int emac_tpd_num_free_descs(struct emac_tx_queue *tx_q)
1177 {
1178 	u32 produce_idx = tx_q->tpd.produce_idx;
1179 	u32 consume_idx = tx_q->tpd.consume_idx;
1180 
1181 	return (consume_idx > produce_idx) ?
1182 		(consume_idx - produce_idx - 1) :
1183 		(tx_q->tpd.count + consume_idx - produce_idx - 1);
1184 }
1185 
1186 /* Process transmit event */
1187 void emac_mac_tx_process(struct emac_adapter *adpt, struct emac_tx_queue *tx_q)
1188 {
1189 	u32 reg = readl_relaxed(adpt->base + tx_q->consume_reg);
1190 	u32 hw_consume_idx, pkts_compl = 0, bytes_compl = 0;
1191 	struct emac_buffer *tpbuf;
1192 
1193 	hw_consume_idx = (reg & tx_q->consume_mask) >> tx_q->consume_shift;
1194 
1195 	while (tx_q->tpd.consume_idx != hw_consume_idx) {
1196 		tpbuf = GET_TPD_BUFFER(tx_q, tx_q->tpd.consume_idx);
1197 		if (tpbuf->dma_addr) {
1198 			dma_unmap_page(adpt->netdev->dev.parent,
1199 				       tpbuf->dma_addr, tpbuf->length,
1200 				       DMA_TO_DEVICE);
1201 			tpbuf->dma_addr = 0;
1202 		}
1203 
1204 		if (tpbuf->skb) {
1205 			pkts_compl++;
1206 			bytes_compl += tpbuf->skb->len;
1207 			dev_kfree_skb_irq(tpbuf->skb);
1208 			tpbuf->skb = NULL;
1209 		}
1210 
1211 		if (++tx_q->tpd.consume_idx == tx_q->tpd.count)
1212 			tx_q->tpd.consume_idx = 0;
1213 	}
1214 
1215 	netdev_completed_queue(adpt->netdev, pkts_compl, bytes_compl);
1216 
1217 	if (netif_queue_stopped(adpt->netdev))
1218 		if (emac_tpd_num_free_descs(tx_q) > (MAX_SKB_FRAGS + 1))
1219 			netif_wake_queue(adpt->netdev);
1220 }
1221 
1222 /* Initialize all queue data structures */
1223 void emac_mac_rx_tx_ring_init_all(struct platform_device *pdev,
1224 				  struct emac_adapter *adpt)
1225 {
1226 	adpt->rx_q.netdev = adpt->netdev;
1227 
1228 	adpt->rx_q.produce_reg  = EMAC_MAILBOX_0;
1229 	adpt->rx_q.produce_mask = RFD0_PROD_IDX_BMSK;
1230 	adpt->rx_q.produce_shift = RFD0_PROD_IDX_SHFT;
1231 
1232 	adpt->rx_q.process_reg  = EMAC_MAILBOX_0;
1233 	adpt->rx_q.process_mask = RFD0_PROC_IDX_BMSK;
1234 	adpt->rx_q.process_shft = RFD0_PROC_IDX_SHFT;
1235 
1236 	adpt->rx_q.consume_reg  = EMAC_MAILBOX_3;
1237 	adpt->rx_q.consume_mask = RFD0_CONS_IDX_BMSK;
1238 	adpt->rx_q.consume_shift = RFD0_CONS_IDX_SHFT;
1239 
1240 	adpt->rx_q.irq          = &adpt->irq;
1241 	adpt->rx_q.intr         = adpt->irq.mask & ISR_RX_PKT;
1242 
1243 	adpt->tx_q.produce_reg  = EMAC_MAILBOX_15;
1244 	adpt->tx_q.produce_mask = NTPD_PROD_IDX_BMSK;
1245 	adpt->tx_q.produce_shift = NTPD_PROD_IDX_SHFT;
1246 
1247 	adpt->tx_q.consume_reg  = EMAC_MAILBOX_2;
1248 	adpt->tx_q.consume_mask = NTPD_CONS_IDX_BMSK;
1249 	adpt->tx_q.consume_shift = NTPD_CONS_IDX_SHFT;
1250 }
1251 
1252 /* Fill up transmit descriptors with TSO and Checksum offload information */
1253 static int emac_tso_csum(struct emac_adapter *adpt,
1254 			 struct emac_tx_queue *tx_q,
1255 			 struct sk_buff *skb,
1256 			 struct emac_tpd *tpd)
1257 {
1258 	unsigned int hdr_len;
1259 	int ret;
1260 
1261 	if (skb_is_gso(skb)) {
1262 		if (skb_header_cloned(skb)) {
1263 			ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
1264 			if (unlikely(ret))
1265 				return ret;
1266 		}
1267 
1268 		if (skb->protocol == htons(ETH_P_IP)) {
1269 			u32 pkt_len = ((unsigned char *)ip_hdr(skb) - skb->data)
1270 				       + ntohs(ip_hdr(skb)->tot_len);
1271 			if (skb->len > pkt_len)
1272 				pskb_trim(skb, pkt_len);
1273 		}
1274 
1275 		hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
1276 		if (unlikely(skb->len == hdr_len)) {
1277 			/* we only need to do csum */
1278 			netif_warn(adpt, tx_err, adpt->netdev,
1279 				   "tso not needed for packet with 0 data\n");
1280 			goto do_csum;
1281 		}
1282 
1283 		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
1284 			ip_hdr(skb)->check = 0;
1285 			tcp_hdr(skb)->check =
1286 				~csum_tcpudp_magic(ip_hdr(skb)->saddr,
1287 						   ip_hdr(skb)->daddr,
1288 						   0, IPPROTO_TCP, 0);
1289 			TPD_IPV4_SET(tpd, 1);
1290 		}
1291 
1292 		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) {
1293 			/* ipv6 tso need an extra tpd */
1294 			struct emac_tpd extra_tpd;
1295 
1296 			memset(tpd, 0, sizeof(*tpd));
1297 			memset(&extra_tpd, 0, sizeof(extra_tpd));
1298 
1299 			ipv6_hdr(skb)->payload_len = 0;
1300 			tcp_hdr(skb)->check =
1301 				~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
1302 						 &ipv6_hdr(skb)->daddr,
1303 						 0, IPPROTO_TCP, 0);
1304 			TPD_PKT_LEN_SET(&extra_tpd, skb->len);
1305 			TPD_LSO_SET(&extra_tpd, 1);
1306 			TPD_LSOV_SET(&extra_tpd, 1);
1307 			emac_tx_tpd_create(adpt, tx_q, &extra_tpd);
1308 			TPD_LSOV_SET(tpd, 1);
1309 		}
1310 
1311 		TPD_LSO_SET(tpd, 1);
1312 		TPD_TCPHDR_OFFSET_SET(tpd, skb_transport_offset(skb));
1313 		TPD_MSS_SET(tpd, skb_shinfo(skb)->gso_size);
1314 		return 0;
1315 	}
1316 
1317 do_csum:
1318 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
1319 		unsigned int css, cso;
1320 
1321 		cso = skb_transport_offset(skb);
1322 		if (unlikely(cso & 0x1)) {
1323 			netdev_err(adpt->netdev,
1324 				   "error: payload offset should be even\n");
1325 			return -EINVAL;
1326 		}
1327 		css = cso + skb->csum_offset;
1328 
1329 		TPD_PAYLOAD_OFFSET_SET(tpd, cso >> 1);
1330 		TPD_CXSUM_OFFSET_SET(tpd, css >> 1);
1331 		TPD_CSX_SET(tpd, 1);
1332 	}
1333 
1334 	return 0;
1335 }
1336 
1337 /* Fill up transmit descriptors */
1338 static void emac_tx_fill_tpd(struct emac_adapter *adpt,
1339 			     struct emac_tx_queue *tx_q, struct sk_buff *skb,
1340 			     struct emac_tpd *tpd)
1341 {
1342 	unsigned int nr_frags = skb_shinfo(skb)->nr_frags;
1343 	unsigned int first = tx_q->tpd.produce_idx;
1344 	unsigned int len = skb_headlen(skb);
1345 	struct emac_buffer *tpbuf = NULL;
1346 	unsigned int mapped_len = 0;
1347 	unsigned int i;
1348 	int count = 0;
1349 	int ret;
1350 
1351 	/* if Large Segment Offload is (in TCP Segmentation Offload struct) */
1352 	if (TPD_LSO(tpd)) {
1353 		mapped_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
1354 
1355 		tpbuf = GET_TPD_BUFFER(tx_q, tx_q->tpd.produce_idx);
1356 		tpbuf->length = mapped_len;
1357 		tpbuf->dma_addr = dma_map_page(adpt->netdev->dev.parent,
1358 					       virt_to_page(skb->data),
1359 					       offset_in_page(skb->data),
1360 					       tpbuf->length,
1361 					       DMA_TO_DEVICE);
1362 		ret = dma_mapping_error(adpt->netdev->dev.parent,
1363 					tpbuf->dma_addr);
1364 		if (ret)
1365 			goto error;
1366 
1367 		TPD_BUFFER_ADDR_L_SET(tpd, lower_32_bits(tpbuf->dma_addr));
1368 		TPD_BUFFER_ADDR_H_SET(tpd, upper_32_bits(tpbuf->dma_addr));
1369 		TPD_BUF_LEN_SET(tpd, tpbuf->length);
1370 		emac_tx_tpd_create(adpt, tx_q, tpd);
1371 		count++;
1372 	}
1373 
1374 	if (mapped_len < len) {
1375 		tpbuf = GET_TPD_BUFFER(tx_q, tx_q->tpd.produce_idx);
1376 		tpbuf->length = len - mapped_len;
1377 		tpbuf->dma_addr = dma_map_page(adpt->netdev->dev.parent,
1378 					       virt_to_page(skb->data +
1379 							    mapped_len),
1380 					       offset_in_page(skb->data +
1381 							      mapped_len),
1382 					       tpbuf->length, DMA_TO_DEVICE);
1383 		ret = dma_mapping_error(adpt->netdev->dev.parent,
1384 					tpbuf->dma_addr);
1385 		if (ret)
1386 			goto error;
1387 
1388 		TPD_BUFFER_ADDR_L_SET(tpd, lower_32_bits(tpbuf->dma_addr));
1389 		TPD_BUFFER_ADDR_H_SET(tpd, upper_32_bits(tpbuf->dma_addr));
1390 		TPD_BUF_LEN_SET(tpd, tpbuf->length);
1391 		emac_tx_tpd_create(adpt, tx_q, tpd);
1392 		count++;
1393 	}
1394 
1395 	for (i = 0; i < nr_frags; i++) {
1396 		struct skb_frag_struct *frag;
1397 
1398 		frag = &skb_shinfo(skb)->frags[i];
1399 
1400 		tpbuf = GET_TPD_BUFFER(tx_q, tx_q->tpd.produce_idx);
1401 		tpbuf->length = frag->size;
1402 		tpbuf->dma_addr = dma_map_page(adpt->netdev->dev.parent,
1403 					       frag->page.p, frag->page_offset,
1404 					       tpbuf->length, DMA_TO_DEVICE);
1405 		ret = dma_mapping_error(adpt->netdev->dev.parent,
1406 					tpbuf->dma_addr);
1407 		if (ret)
1408 			goto error;
1409 
1410 		TPD_BUFFER_ADDR_L_SET(tpd, lower_32_bits(tpbuf->dma_addr));
1411 		TPD_BUFFER_ADDR_H_SET(tpd, upper_32_bits(tpbuf->dma_addr));
1412 		TPD_BUF_LEN_SET(tpd, tpbuf->length);
1413 		emac_tx_tpd_create(adpt, tx_q, tpd);
1414 		count++;
1415 	}
1416 
1417 	/* The last tpd */
1418 	wmb();
1419 	emac_tx_tpd_mark_last(adpt, tx_q);
1420 
1421 	/* The last buffer info contain the skb address,
1422 	 * so it will be freed after unmap
1423 	 */
1424 	tpbuf->skb = skb;
1425 
1426 	return;
1427 
1428 error:
1429 	/* One of the memory mappings failed, so undo everything */
1430 	tx_q->tpd.produce_idx = first;
1431 
1432 	while (count--) {
1433 		tpbuf = GET_TPD_BUFFER(tx_q, first);
1434 		dma_unmap_page(adpt->netdev->dev.parent, tpbuf->dma_addr,
1435 			       tpbuf->length, DMA_TO_DEVICE);
1436 		tpbuf->dma_addr = 0;
1437 		tpbuf->length = 0;
1438 
1439 		if (++first == tx_q->tpd.count)
1440 			first = 0;
1441 	}
1442 
1443 	dev_kfree_skb(skb);
1444 }
1445 
1446 /* Transmit the packet using specified transmit queue */
1447 int emac_mac_tx_buf_send(struct emac_adapter *adpt, struct emac_tx_queue *tx_q,
1448 			 struct sk_buff *skb)
1449 {
1450 	struct emac_tpd tpd;
1451 	u32 prod_idx;
1452 
1453 	memset(&tpd, 0, sizeof(tpd));
1454 
1455 	if (emac_tso_csum(adpt, tx_q, skb, &tpd) != 0) {
1456 		dev_kfree_skb_any(skb);
1457 		return NETDEV_TX_OK;
1458 	}
1459 
1460 	if (skb_vlan_tag_present(skb)) {
1461 		u16 tag;
1462 
1463 		EMAC_VLAN_TO_TAG(skb_vlan_tag_get(skb), tag);
1464 		TPD_CVLAN_TAG_SET(&tpd, tag);
1465 		TPD_INSTC_SET(&tpd, 1);
1466 	}
1467 
1468 	if (skb_network_offset(skb) != ETH_HLEN)
1469 		TPD_TYP_SET(&tpd, 1);
1470 
1471 	emac_tx_fill_tpd(adpt, tx_q, skb, &tpd);
1472 
1473 	netdev_sent_queue(adpt->netdev, skb->len);
1474 
1475 	/* Make sure the are enough free descriptors to hold one
1476 	 * maximum-sized SKB.  We need one desc for each fragment,
1477 	 * one for the checksum (emac_tso_csum), one for TSO, and
1478 	 * and one for the SKB header.
1479 	 */
1480 	if (emac_tpd_num_free_descs(tx_q) < (MAX_SKB_FRAGS + 3))
1481 		netif_stop_queue(adpt->netdev);
1482 
1483 	/* update produce idx */
1484 	prod_idx = (tx_q->tpd.produce_idx << tx_q->produce_shift) &
1485 		    tx_q->produce_mask;
1486 	emac_reg_update32(adpt->base + tx_q->produce_reg,
1487 			  tx_q->produce_mask, prod_idx);
1488 
1489 	return NETDEV_TX_OK;
1490 }
1491