1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.
3  */
4 
5 /* Qualcomm Technologies, Inc. EMAC Ethernet Controller MAC layer support
6  */
7 
8 #include <linux/tcp.h>
9 #include <linux/ip.h>
10 #include <linux/ipv6.h>
11 #include <linux/crc32.h>
12 #include <linux/if_vlan.h>
13 #include <linux/jiffies.h>
14 #include <linux/phy.h>
15 #include <linux/of.h>
16 #include <net/ip6_checksum.h>
17 #include "emac.h"
18 #include "emac-sgmii.h"
19 
20 /* EMAC_MAC_CTRL */
21 #define SINGLE_PAUSE_MODE       	0x10000000
22 #define DEBUG_MODE                      0x08000000
23 #define BROAD_EN                        0x04000000
24 #define MULTI_ALL                       0x02000000
25 #define RX_CHKSUM_EN                    0x01000000
26 #define HUGE                            0x00800000
27 #define SPEED(x)			(((x) & 0x3) << 20)
28 #define SPEED_MASK			SPEED(0x3)
29 #define SIMR                            0x00080000
30 #define TPAUSE                          0x00010000
31 #define PROM_MODE                       0x00008000
32 #define VLAN_STRIP                      0x00004000
33 #define PRLEN_BMSK                      0x00003c00
34 #define PRLEN_SHFT                      10
35 #define HUGEN                           0x00000200
36 #define FLCHK                           0x00000100
37 #define PCRCE                           0x00000080
38 #define CRCE                            0x00000040
39 #define FULLD                           0x00000020
40 #define MAC_LP_EN                       0x00000010
41 #define RXFC                            0x00000008
42 #define TXFC                            0x00000004
43 #define RXEN                            0x00000002
44 #define TXEN                            0x00000001
45 
46 /* EMAC_DESC_CTRL_3 */
47 #define RFD_RING_SIZE_BMSK                                       0xfff
48 
49 /* EMAC_DESC_CTRL_4 */
50 #define RX_BUFFER_SIZE_BMSK                                     0xffff
51 
52 /* EMAC_DESC_CTRL_6 */
53 #define RRD_RING_SIZE_BMSK                                       0xfff
54 
55 /* EMAC_DESC_CTRL_9 */
56 #define TPD_RING_SIZE_BMSK                                      0xffff
57 
58 /* EMAC_TXQ_CTRL_0 */
59 #define NUM_TXF_BURST_PREF_BMSK                             0xffff0000
60 #define NUM_TXF_BURST_PREF_SHFT                                     16
61 #define LS_8023_SP                                                0x80
62 #define TXQ_MODE                                                  0x40
63 #define TXQ_EN                                                    0x20
64 #define IP_OP_SP                                                  0x10
65 #define NUM_TPD_BURST_PREF_BMSK                                    0xf
66 #define NUM_TPD_BURST_PREF_SHFT                                      0
67 
68 /* EMAC_TXQ_CTRL_1 */
69 #define JUMBO_TASK_OFFLOAD_THRESHOLD_BMSK                        0x7ff
70 
71 /* EMAC_TXQ_CTRL_2 */
72 #define TXF_HWM_BMSK                                         0xfff0000
73 #define TXF_LWM_BMSK                                             0xfff
74 
75 /* EMAC_RXQ_CTRL_0 */
76 #define RXQ_EN                                                 BIT(31)
77 #define CUT_THRU_EN                                            BIT(30)
78 #define RSS_HASH_EN                                            BIT(29)
79 #define NUM_RFD_BURST_PREF_BMSK                              0x3f00000
80 #define NUM_RFD_BURST_PREF_SHFT                                     20
81 #define IDT_TABLE_SIZE_BMSK                                    0x1ff00
82 #define IDT_TABLE_SIZE_SHFT                                          8
83 #define SP_IPV6                                                   0x80
84 
85 /* EMAC_RXQ_CTRL_1 */
86 #define JUMBO_1KAH_BMSK                                         0xf000
87 #define JUMBO_1KAH_SHFT                                             12
88 #define RFD_PREF_LOW_TH                                           0x10
89 #define RFD_PREF_LOW_THRESHOLD_BMSK                              0xfc0
90 #define RFD_PREF_LOW_THRESHOLD_SHFT                                  6
91 #define RFD_PREF_UP_TH                                            0x10
92 #define RFD_PREF_UP_THRESHOLD_BMSK                                0x3f
93 #define RFD_PREF_UP_THRESHOLD_SHFT                                   0
94 
95 /* EMAC_RXQ_CTRL_2 */
96 #define RXF_DOF_THRESFHOLD                                       0x1a0
97 #define RXF_DOF_THRESHOLD_BMSK                               0xfff0000
98 #define RXF_DOF_THRESHOLD_SHFT                                      16
99 #define RXF_UOF_THRESFHOLD                                        0xbe
100 #define RXF_UOF_THRESHOLD_BMSK                                   0xfff
101 #define RXF_UOF_THRESHOLD_SHFT                                       0
102 
103 /* EMAC_RXQ_CTRL_3 */
104 #define RXD_TIMER_BMSK                                      0xffff0000
105 #define RXD_THRESHOLD_BMSK                                       0xfff
106 #define RXD_THRESHOLD_SHFT                                           0
107 
108 /* EMAC_DMA_CTRL */
109 #define DMAW_DLY_CNT_BMSK                                      0xf0000
110 #define DMAW_DLY_CNT_SHFT                                           16
111 #define DMAR_DLY_CNT_BMSK                                       0xf800
112 #define DMAR_DLY_CNT_SHFT                                           11
113 #define DMAR_REQ_PRI                                             0x400
114 #define REGWRBLEN_BMSK                                           0x380
115 #define REGWRBLEN_SHFT                                               7
116 #define REGRDBLEN_BMSK                                            0x70
117 #define REGRDBLEN_SHFT                                               4
118 #define OUT_ORDER_MODE                                             0x4
119 #define ENH_ORDER_MODE                                             0x2
120 #define IN_ORDER_MODE                                              0x1
121 
122 /* EMAC_MAILBOX_13 */
123 #define RFD3_PROC_IDX_BMSK                                   0xfff0000
124 #define RFD3_PROC_IDX_SHFT                                          16
125 #define RFD3_PROD_IDX_BMSK                                       0xfff
126 #define RFD3_PROD_IDX_SHFT                                           0
127 
128 /* EMAC_MAILBOX_2 */
129 #define NTPD_CONS_IDX_BMSK                                  0xffff0000
130 #define NTPD_CONS_IDX_SHFT                                          16
131 
132 /* EMAC_MAILBOX_3 */
133 #define RFD0_CONS_IDX_BMSK                                       0xfff
134 #define RFD0_CONS_IDX_SHFT                                           0
135 
136 /* EMAC_MAILBOX_11 */
137 #define H3TPD_PROD_IDX_BMSK                                 0xffff0000
138 #define H3TPD_PROD_IDX_SHFT                                         16
139 
140 /* EMAC_AXI_MAST_CTRL */
141 #define DATA_BYTE_SWAP                                             0x8
142 #define MAX_BOUND                                                  0x2
143 #define MAX_BTYPE                                                  0x1
144 
145 /* EMAC_MAILBOX_12 */
146 #define H3TPD_CONS_IDX_BMSK                                 0xffff0000
147 #define H3TPD_CONS_IDX_SHFT                                         16
148 
149 /* EMAC_MAILBOX_9 */
150 #define H2TPD_PROD_IDX_BMSK                                     0xffff
151 #define H2TPD_PROD_IDX_SHFT                                          0
152 
153 /* EMAC_MAILBOX_10 */
154 #define H1TPD_CONS_IDX_BMSK                                 0xffff0000
155 #define H1TPD_CONS_IDX_SHFT                                         16
156 #define H2TPD_CONS_IDX_BMSK                                     0xffff
157 #define H2TPD_CONS_IDX_SHFT                                          0
158 
159 /* EMAC_ATHR_HEADER_CTRL */
160 #define HEADER_CNT_EN                                              0x2
161 #define HEADER_ENABLE                                              0x1
162 
163 /* EMAC_MAILBOX_0 */
164 #define RFD0_PROC_IDX_BMSK                                   0xfff0000
165 #define RFD0_PROC_IDX_SHFT                                          16
166 #define RFD0_PROD_IDX_BMSK                                       0xfff
167 #define RFD0_PROD_IDX_SHFT                                           0
168 
169 /* EMAC_MAILBOX_5 */
170 #define RFD1_PROC_IDX_BMSK                                   0xfff0000
171 #define RFD1_PROC_IDX_SHFT                                          16
172 #define RFD1_PROD_IDX_BMSK                                       0xfff
173 #define RFD1_PROD_IDX_SHFT                                           0
174 
175 /* EMAC_MISC_CTRL */
176 #define RX_UNCPL_INT_EN                                            0x1
177 
178 /* EMAC_MAILBOX_7 */
179 #define RFD2_CONS_IDX_BMSK                                   0xfff0000
180 #define RFD2_CONS_IDX_SHFT                                          16
181 #define RFD1_CONS_IDX_BMSK                                       0xfff
182 #define RFD1_CONS_IDX_SHFT                                           0
183 
184 /* EMAC_MAILBOX_8 */
185 #define RFD3_CONS_IDX_BMSK                                       0xfff
186 #define RFD3_CONS_IDX_SHFT                                           0
187 
188 /* EMAC_MAILBOX_15 */
189 #define NTPD_PROD_IDX_BMSK                                      0xffff
190 #define NTPD_PROD_IDX_SHFT                                           0
191 
192 /* EMAC_MAILBOX_16 */
193 #define H1TPD_PROD_IDX_BMSK                                     0xffff
194 #define H1TPD_PROD_IDX_SHFT                                          0
195 
196 #define RXQ0_RSS_HSTYP_IPV6_TCP_EN                                0x20
197 #define RXQ0_RSS_HSTYP_IPV6_EN                                    0x10
198 #define RXQ0_RSS_HSTYP_IPV4_TCP_EN                                 0x8
199 #define RXQ0_RSS_HSTYP_IPV4_EN                                     0x4
200 
201 /* EMAC_EMAC_WRAPPER_TX_TS_INX */
202 #define EMAC_WRAPPER_TX_TS_EMPTY                               BIT(31)
203 #define EMAC_WRAPPER_TX_TS_INX_BMSK                             0xffff
204 
205 struct emac_skb_cb {
206 	u32           tpd_idx;
207 	unsigned long jiffies;
208 };
209 
210 #define EMAC_SKB_CB(skb)	((struct emac_skb_cb *)(skb)->cb)
211 #define EMAC_RSS_IDT_SIZE	256
212 #define JUMBO_1KAH		0x4
213 #define RXD_TH			0x100
214 #define EMAC_TPD_LAST_FRAGMENT	0x80000000
215 #define EMAC_TPD_TSTAMP_SAVE	0x80000000
216 
217 /* EMAC Errors in emac_rrd.word[3] */
218 #define EMAC_RRD_L4F		BIT(14)
219 #define EMAC_RRD_IPF		BIT(15)
220 #define EMAC_RRD_CRC		BIT(21)
221 #define EMAC_RRD_FAE		BIT(22)
222 #define EMAC_RRD_TRN		BIT(23)
223 #define EMAC_RRD_RNT		BIT(24)
224 #define EMAC_RRD_INC		BIT(25)
225 #define EMAC_RRD_FOV		BIT(29)
226 #define EMAC_RRD_LEN		BIT(30)
227 
228 /* Error bits that will result in a received frame being discarded */
229 #define EMAC_RRD_ERROR (EMAC_RRD_IPF | EMAC_RRD_CRC | EMAC_RRD_FAE | \
230 			EMAC_RRD_TRN | EMAC_RRD_RNT | EMAC_RRD_INC | \
231 			EMAC_RRD_FOV | EMAC_RRD_LEN)
232 #define EMAC_RRD_STATS_DW_IDX 3
233 
234 #define EMAC_RRD(RXQ, SIZE, IDX)	((RXQ)->rrd.v_addr + (SIZE * (IDX)))
235 #define EMAC_RFD(RXQ, SIZE, IDX)	((RXQ)->rfd.v_addr + (SIZE * (IDX)))
236 #define EMAC_TPD(TXQ, SIZE, IDX)	((TXQ)->tpd.v_addr + (SIZE * (IDX)))
237 
238 #define GET_RFD_BUFFER(RXQ, IDX)	(&((RXQ)->rfd.rfbuff[(IDX)]))
239 #define GET_TPD_BUFFER(RTQ, IDX)	(&((RTQ)->tpd.tpbuff[(IDX)]))
240 
241 #define EMAC_TX_POLL_HWTXTSTAMP_THRESHOLD	8
242 
243 #define ISR_RX_PKT      (\
244 	RX_PKT_INT0     |\
245 	RX_PKT_INT1     |\
246 	RX_PKT_INT2     |\
247 	RX_PKT_INT3)
248 
249 void emac_mac_multicast_addr_set(struct emac_adapter *adpt, u8 *addr)
250 {
251 	u32 crc32, bit, reg, mta;
252 
253 	/* Calculate the CRC of the MAC address */
254 	crc32 = ether_crc(ETH_ALEN, addr);
255 
256 	/* The HASH Table is an array of 2 32-bit registers. It is
257 	 * treated like an array of 64 bits (BitArray[hash_value]).
258 	 * Use the upper 6 bits of the above CRC as the hash value.
259 	 */
260 	reg = (crc32 >> 31) & 0x1;
261 	bit = (crc32 >> 26) & 0x1F;
262 
263 	mta = readl(adpt->base + EMAC_HASH_TAB_REG0 + (reg << 2));
264 	mta |= BIT(bit);
265 	writel(mta, adpt->base + EMAC_HASH_TAB_REG0 + (reg << 2));
266 }
267 
268 void emac_mac_multicast_addr_clear(struct emac_adapter *adpt)
269 {
270 	writel(0, adpt->base + EMAC_HASH_TAB_REG0);
271 	writel(0, adpt->base + EMAC_HASH_TAB_REG1);
272 }
273 
274 /* definitions for RSS */
275 #define EMAC_RSS_KEY(_i, _type) \
276 		(EMAC_RSS_KEY0 + ((_i) * sizeof(_type)))
277 #define EMAC_RSS_TBL(_i, _type) \
278 		(EMAC_IDT_TABLE0 + ((_i) * sizeof(_type)))
279 
280 /* Config MAC modes */
281 void emac_mac_mode_config(struct emac_adapter *adpt)
282 {
283 	struct net_device *netdev = adpt->netdev;
284 	u32 mac;
285 
286 	mac = readl(adpt->base + EMAC_MAC_CTRL);
287 	mac &= ~(VLAN_STRIP | PROM_MODE | MULTI_ALL | MAC_LP_EN);
288 
289 	if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX)
290 		mac |= VLAN_STRIP;
291 
292 	if (netdev->flags & IFF_PROMISC)
293 		mac |= PROM_MODE;
294 
295 	if (netdev->flags & IFF_ALLMULTI)
296 		mac |= MULTI_ALL;
297 
298 	writel(mac, adpt->base + EMAC_MAC_CTRL);
299 }
300 
301 /* Config descriptor rings */
302 static void emac_mac_dma_rings_config(struct emac_adapter *adpt)
303 {
304 	/* TPD (Transmit Packet Descriptor) */
305 	writel(upper_32_bits(adpt->tx_q.tpd.dma_addr),
306 	       adpt->base + EMAC_DESC_CTRL_1);
307 
308 	writel(lower_32_bits(adpt->tx_q.tpd.dma_addr),
309 	       adpt->base + EMAC_DESC_CTRL_8);
310 
311 	writel(adpt->tx_q.tpd.count & TPD_RING_SIZE_BMSK,
312 	       adpt->base + EMAC_DESC_CTRL_9);
313 
314 	/* RFD (Receive Free Descriptor) & RRD (Receive Return Descriptor) */
315 	writel(upper_32_bits(adpt->rx_q.rfd.dma_addr),
316 	       adpt->base + EMAC_DESC_CTRL_0);
317 
318 	writel(lower_32_bits(adpt->rx_q.rfd.dma_addr),
319 	       adpt->base + EMAC_DESC_CTRL_2);
320 	writel(lower_32_bits(adpt->rx_q.rrd.dma_addr),
321 	       adpt->base + EMAC_DESC_CTRL_5);
322 
323 	writel(adpt->rx_q.rfd.count & RFD_RING_SIZE_BMSK,
324 	       adpt->base + EMAC_DESC_CTRL_3);
325 	writel(adpt->rx_q.rrd.count & RRD_RING_SIZE_BMSK,
326 	       adpt->base + EMAC_DESC_CTRL_6);
327 
328 	writel(adpt->rxbuf_size & RX_BUFFER_SIZE_BMSK,
329 	       adpt->base + EMAC_DESC_CTRL_4);
330 
331 	writel(0, adpt->base + EMAC_DESC_CTRL_11);
332 
333 	/* Load all of the base addresses above and ensure that triggering HW to
334 	 * read ring pointers is flushed
335 	 */
336 	writel(1, adpt->base + EMAC_INTER_SRAM_PART9);
337 }
338 
339 /* Config transmit parameters */
340 static void emac_mac_tx_config(struct emac_adapter *adpt)
341 {
342 	u32 val;
343 
344 	writel((EMAC_MAX_TX_OFFLOAD_THRESH >> 3) &
345 	       JUMBO_TASK_OFFLOAD_THRESHOLD_BMSK, adpt->base + EMAC_TXQ_CTRL_1);
346 
347 	val = (adpt->tpd_burst << NUM_TPD_BURST_PREF_SHFT) &
348 	       NUM_TPD_BURST_PREF_BMSK;
349 
350 	val |= TXQ_MODE | LS_8023_SP;
351 	val |= (0x0100 << NUM_TXF_BURST_PREF_SHFT) &
352 		NUM_TXF_BURST_PREF_BMSK;
353 
354 	writel(val, adpt->base + EMAC_TXQ_CTRL_0);
355 	emac_reg_update32(adpt->base + EMAC_TXQ_CTRL_2,
356 			  (TXF_HWM_BMSK | TXF_LWM_BMSK), 0);
357 }
358 
359 /* Config receive parameters */
360 static void emac_mac_rx_config(struct emac_adapter *adpt)
361 {
362 	u32 val;
363 
364 	val = (adpt->rfd_burst << NUM_RFD_BURST_PREF_SHFT) &
365 	       NUM_RFD_BURST_PREF_BMSK;
366 	val |= (SP_IPV6 | CUT_THRU_EN);
367 
368 	writel(val, adpt->base + EMAC_RXQ_CTRL_0);
369 
370 	val = readl(adpt->base + EMAC_RXQ_CTRL_1);
371 	val &= ~(JUMBO_1KAH_BMSK | RFD_PREF_LOW_THRESHOLD_BMSK |
372 		 RFD_PREF_UP_THRESHOLD_BMSK);
373 	val |= (JUMBO_1KAH << JUMBO_1KAH_SHFT) |
374 		(RFD_PREF_LOW_TH << RFD_PREF_LOW_THRESHOLD_SHFT) |
375 		(RFD_PREF_UP_TH  << RFD_PREF_UP_THRESHOLD_SHFT);
376 	writel(val, adpt->base + EMAC_RXQ_CTRL_1);
377 
378 	val = readl(adpt->base + EMAC_RXQ_CTRL_2);
379 	val &= ~(RXF_DOF_THRESHOLD_BMSK | RXF_UOF_THRESHOLD_BMSK);
380 	val |= (RXF_DOF_THRESFHOLD  << RXF_DOF_THRESHOLD_SHFT) |
381 		(RXF_UOF_THRESFHOLD << RXF_UOF_THRESHOLD_SHFT);
382 	writel(val, adpt->base + EMAC_RXQ_CTRL_2);
383 
384 	val = readl(adpt->base + EMAC_RXQ_CTRL_3);
385 	val &= ~(RXD_TIMER_BMSK | RXD_THRESHOLD_BMSK);
386 	val |= RXD_TH << RXD_THRESHOLD_SHFT;
387 	writel(val, adpt->base + EMAC_RXQ_CTRL_3);
388 }
389 
390 /* Config dma */
391 static void emac_mac_dma_config(struct emac_adapter *adpt)
392 {
393 	u32 dma_ctrl = DMAR_REQ_PRI;
394 
395 	switch (adpt->dma_order) {
396 	case emac_dma_ord_in:
397 		dma_ctrl |= IN_ORDER_MODE;
398 		break;
399 	case emac_dma_ord_enh:
400 		dma_ctrl |= ENH_ORDER_MODE;
401 		break;
402 	case emac_dma_ord_out:
403 		dma_ctrl |= OUT_ORDER_MODE;
404 		break;
405 	default:
406 		break;
407 	}
408 
409 	dma_ctrl |= (((u32)adpt->dmar_block) << REGRDBLEN_SHFT) &
410 						REGRDBLEN_BMSK;
411 	dma_ctrl |= (((u32)adpt->dmaw_block) << REGWRBLEN_SHFT) &
412 						REGWRBLEN_BMSK;
413 	dma_ctrl |= (((u32)adpt->dmar_dly_cnt) << DMAR_DLY_CNT_SHFT) &
414 						DMAR_DLY_CNT_BMSK;
415 	dma_ctrl |= (((u32)adpt->dmaw_dly_cnt) << DMAW_DLY_CNT_SHFT) &
416 						DMAW_DLY_CNT_BMSK;
417 
418 	/* config DMA and ensure that configuration is flushed to HW */
419 	writel(dma_ctrl, adpt->base + EMAC_DMA_CTRL);
420 }
421 
422 /* set MAC address */
423 static void emac_set_mac_address(struct emac_adapter *adpt, const u8 *addr)
424 {
425 	u32 sta;
426 
427 	/* for example: 00-A0-C6-11-22-33
428 	 * 0<-->C6112233, 1<-->00A0.
429 	 */
430 
431 	/* low 32bit word */
432 	sta = (((u32)addr[2]) << 24) | (((u32)addr[3]) << 16) |
433 	      (((u32)addr[4]) << 8)  | (((u32)addr[5]));
434 	writel(sta, adpt->base + EMAC_MAC_STA_ADDR0);
435 
436 	/* hight 32bit word */
437 	sta = (((u32)addr[0]) << 8) | (u32)addr[1];
438 	writel(sta, adpt->base + EMAC_MAC_STA_ADDR1);
439 }
440 
441 static void emac_mac_config(struct emac_adapter *adpt)
442 {
443 	struct net_device *netdev = adpt->netdev;
444 	unsigned int max_frame;
445 	u32 val;
446 
447 	emac_set_mac_address(adpt, netdev->dev_addr);
448 
449 	max_frame = netdev->mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
450 	adpt->rxbuf_size = netdev->mtu > EMAC_DEF_RX_BUF_SIZE ?
451 		ALIGN(max_frame, 8) : EMAC_DEF_RX_BUF_SIZE;
452 
453 	emac_mac_dma_rings_config(adpt);
454 
455 	writel(netdev->mtu + ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN,
456 	       adpt->base + EMAC_MAX_FRAM_LEN_CTRL);
457 
458 	emac_mac_tx_config(adpt);
459 	emac_mac_rx_config(adpt);
460 	emac_mac_dma_config(adpt);
461 
462 	val = readl(adpt->base + EMAC_AXI_MAST_CTRL);
463 	val &= ~(DATA_BYTE_SWAP | MAX_BOUND);
464 	val |= MAX_BTYPE;
465 	writel(val, adpt->base + EMAC_AXI_MAST_CTRL);
466 	writel(0, adpt->base + EMAC_CLK_GATE_CTRL);
467 	writel(RX_UNCPL_INT_EN, adpt->base + EMAC_MISC_CTRL);
468 }
469 
470 void emac_mac_reset(struct emac_adapter *adpt)
471 {
472 	emac_mac_stop(adpt);
473 
474 	emac_reg_update32(adpt->base + EMAC_DMA_MAS_CTRL, 0, SOFT_RST);
475 	usleep_range(100, 150); /* reset may take up to 100usec */
476 
477 	/* interrupt clear-on-read */
478 	emac_reg_update32(adpt->base + EMAC_DMA_MAS_CTRL, 0, INT_RD_CLR_EN);
479 }
480 
481 static void emac_mac_start(struct emac_adapter *adpt)
482 {
483 	struct phy_device *phydev = adpt->phydev;
484 	u32 mac, csr1;
485 
486 	/* enable tx queue */
487 	emac_reg_update32(adpt->base + EMAC_TXQ_CTRL_0, 0, TXQ_EN);
488 
489 	/* enable rx queue */
490 	emac_reg_update32(adpt->base + EMAC_RXQ_CTRL_0, 0, RXQ_EN);
491 
492 	/* enable mac control */
493 	mac = readl(adpt->base + EMAC_MAC_CTRL);
494 	csr1 = readl(adpt->csr + EMAC_EMAC_WRAPPER_CSR1);
495 
496 	mac |= TXEN | RXEN;     /* enable RX/TX */
497 
498 	/* Configure MAC flow control. If set to automatic, then match
499 	 * whatever the PHY does. Otherwise, enable or disable it, depending
500 	 * on what the user configured via ethtool.
501 	 */
502 	mac &= ~(RXFC | TXFC);
503 
504 	if (adpt->automatic) {
505 		/* If it's set to automatic, then update our local values */
506 		adpt->rx_flow_control = phydev->pause;
507 		adpt->tx_flow_control = phydev->pause != phydev->asym_pause;
508 	}
509 	mac |= adpt->rx_flow_control ? RXFC : 0;
510 	mac |= adpt->tx_flow_control ? TXFC : 0;
511 
512 	/* setup link speed */
513 	mac &= ~SPEED_MASK;
514 	if (phydev->speed == SPEED_1000) {
515 		mac |= SPEED(2);
516 		csr1 |= FREQ_MODE;
517 	} else {
518 		mac |= SPEED(1);
519 		csr1 &= ~FREQ_MODE;
520 	}
521 
522 	if (phydev->duplex == DUPLEX_FULL)
523 		mac |= FULLD;
524 	else
525 		mac &= ~FULLD;
526 
527 	/* other parameters */
528 	mac |= (CRCE | PCRCE);
529 	mac |= ((adpt->preamble << PRLEN_SHFT) & PRLEN_BMSK);
530 	mac |= BROAD_EN;
531 	mac |= FLCHK;
532 	mac &= ~RX_CHKSUM_EN;
533 	mac &= ~(HUGEN | VLAN_STRIP | TPAUSE | SIMR | HUGE | MULTI_ALL |
534 		 DEBUG_MODE | SINGLE_PAUSE_MODE);
535 
536 	/* Enable single-pause-frame mode if requested.
537 	 *
538 	 * If enabled, the EMAC will send a single pause frame when the RX
539 	 * queue is full.  This normally leads to packet loss because
540 	 * the pause frame disables the remote MAC only for 33ms (the quanta),
541 	 * and then the remote MAC continues sending packets even though
542 	 * the RX queue is still full.
543 	 *
544 	 * If disabled, the EMAC sends a pause frame every 31ms until the RX
545 	 * queue is no longer full.  Normally, this is the preferred
546 	 * method of operation.  However, when the system is hung (e.g.
547 	 * cores are halted), the EMAC interrupt handler is never called
548 	 * and so the RX queue fills up quickly and stays full.  The resuling
549 	 * non-stop "flood" of pause frames sometimes has the effect of
550 	 * disabling nearby switches.  In some cases, other nearby switches
551 	 * are also affected, shutting down the entire network.
552 	 *
553 	 * The user can enable or disable single-pause-frame mode
554 	 * via ethtool.
555 	 */
556 	mac |= adpt->single_pause_mode ? SINGLE_PAUSE_MODE : 0;
557 
558 	writel_relaxed(csr1, adpt->csr + EMAC_EMAC_WRAPPER_CSR1);
559 
560 	writel_relaxed(mac, adpt->base + EMAC_MAC_CTRL);
561 
562 	/* enable interrupt read clear, low power sleep mode and
563 	 * the irq moderators
564 	 */
565 
566 	writel_relaxed(adpt->irq_mod, adpt->base + EMAC_IRQ_MOD_TIM_INIT);
567 	writel_relaxed(INT_RD_CLR_EN | LPW_MODE | IRQ_MODERATOR_EN |
568 			IRQ_MODERATOR2_EN, adpt->base + EMAC_DMA_MAS_CTRL);
569 
570 	emac_mac_mode_config(adpt);
571 
572 	emac_reg_update32(adpt->base + EMAC_ATHR_HEADER_CTRL,
573 			  (HEADER_ENABLE | HEADER_CNT_EN), 0);
574 }
575 
576 void emac_mac_stop(struct emac_adapter *adpt)
577 {
578 	emac_reg_update32(adpt->base + EMAC_RXQ_CTRL_0, RXQ_EN, 0);
579 	emac_reg_update32(adpt->base + EMAC_TXQ_CTRL_0, TXQ_EN, 0);
580 	emac_reg_update32(adpt->base + EMAC_MAC_CTRL, TXEN | RXEN, 0);
581 	usleep_range(1000, 1050); /* stopping mac may take upto 1msec */
582 }
583 
584 /* Free all descriptors of given transmit queue */
585 static void emac_tx_q_descs_free(struct emac_adapter *adpt)
586 {
587 	struct emac_tx_queue *tx_q = &adpt->tx_q;
588 	unsigned int i;
589 	size_t size;
590 
591 	/* ring already cleared, nothing to do */
592 	if (!tx_q->tpd.tpbuff)
593 		return;
594 
595 	for (i = 0; i < tx_q->tpd.count; i++) {
596 		struct emac_buffer *tpbuf = GET_TPD_BUFFER(tx_q, i);
597 
598 		if (tpbuf->dma_addr) {
599 			dma_unmap_single(adpt->netdev->dev.parent,
600 					 tpbuf->dma_addr, tpbuf->length,
601 					 DMA_TO_DEVICE);
602 			tpbuf->dma_addr = 0;
603 		}
604 		if (tpbuf->skb) {
605 			dev_kfree_skb_any(tpbuf->skb);
606 			tpbuf->skb = NULL;
607 		}
608 	}
609 
610 	size = sizeof(struct emac_buffer) * tx_q->tpd.count;
611 	memset(tx_q->tpd.tpbuff, 0, size);
612 
613 	/* clear the descriptor ring */
614 	memset(tx_q->tpd.v_addr, 0, tx_q->tpd.size);
615 
616 	tx_q->tpd.consume_idx = 0;
617 	tx_q->tpd.produce_idx = 0;
618 }
619 
620 /* Free all descriptors of given receive queue */
621 static void emac_rx_q_free_descs(struct emac_adapter *adpt)
622 {
623 	struct device *dev = adpt->netdev->dev.parent;
624 	struct emac_rx_queue *rx_q = &adpt->rx_q;
625 	unsigned int i;
626 	size_t size;
627 
628 	/* ring already cleared, nothing to do */
629 	if (!rx_q->rfd.rfbuff)
630 		return;
631 
632 	for (i = 0; i < rx_q->rfd.count; i++) {
633 		struct emac_buffer *rfbuf = GET_RFD_BUFFER(rx_q, i);
634 
635 		if (rfbuf->dma_addr) {
636 			dma_unmap_single(dev, rfbuf->dma_addr, rfbuf->length,
637 					 DMA_FROM_DEVICE);
638 			rfbuf->dma_addr = 0;
639 		}
640 		if (rfbuf->skb) {
641 			dev_kfree_skb(rfbuf->skb);
642 			rfbuf->skb = NULL;
643 		}
644 	}
645 
646 	size =  sizeof(struct emac_buffer) * rx_q->rfd.count;
647 	memset(rx_q->rfd.rfbuff, 0, size);
648 
649 	/* clear the descriptor rings */
650 	memset(rx_q->rrd.v_addr, 0, rx_q->rrd.size);
651 	rx_q->rrd.produce_idx = 0;
652 	rx_q->rrd.consume_idx = 0;
653 
654 	memset(rx_q->rfd.v_addr, 0, rx_q->rfd.size);
655 	rx_q->rfd.produce_idx = 0;
656 	rx_q->rfd.consume_idx = 0;
657 }
658 
659 /* Free all buffers associated with given transmit queue */
660 static void emac_tx_q_bufs_free(struct emac_adapter *adpt)
661 {
662 	struct emac_tx_queue *tx_q = &adpt->tx_q;
663 
664 	emac_tx_q_descs_free(adpt);
665 
666 	kfree(tx_q->tpd.tpbuff);
667 	tx_q->tpd.tpbuff = NULL;
668 	tx_q->tpd.v_addr = NULL;
669 	tx_q->tpd.dma_addr = 0;
670 	tx_q->tpd.size = 0;
671 }
672 
673 /* Allocate TX descriptor ring for the given transmit queue */
674 static int emac_tx_q_desc_alloc(struct emac_adapter *adpt,
675 				struct emac_tx_queue *tx_q)
676 {
677 	struct emac_ring_header *ring_header = &adpt->ring_header;
678 	int node = dev_to_node(adpt->netdev->dev.parent);
679 	size_t size;
680 
681 	size = sizeof(struct emac_buffer) * tx_q->tpd.count;
682 	tx_q->tpd.tpbuff = kzalloc_node(size, GFP_KERNEL, node);
683 	if (!tx_q->tpd.tpbuff)
684 		return -ENOMEM;
685 
686 	tx_q->tpd.size = tx_q->tpd.count * (adpt->tpd_size * 4);
687 	tx_q->tpd.dma_addr = ring_header->dma_addr + ring_header->used;
688 	tx_q->tpd.v_addr = ring_header->v_addr + ring_header->used;
689 	ring_header->used += ALIGN(tx_q->tpd.size, 8);
690 	tx_q->tpd.produce_idx = 0;
691 	tx_q->tpd.consume_idx = 0;
692 
693 	return 0;
694 }
695 
696 /* Free all buffers associated with given transmit queue */
697 static void emac_rx_q_bufs_free(struct emac_adapter *adpt)
698 {
699 	struct emac_rx_queue *rx_q = &adpt->rx_q;
700 
701 	emac_rx_q_free_descs(adpt);
702 
703 	kfree(rx_q->rfd.rfbuff);
704 	rx_q->rfd.rfbuff   = NULL;
705 
706 	rx_q->rfd.v_addr   = NULL;
707 	rx_q->rfd.dma_addr = 0;
708 	rx_q->rfd.size     = 0;
709 
710 	rx_q->rrd.v_addr   = NULL;
711 	rx_q->rrd.dma_addr = 0;
712 	rx_q->rrd.size     = 0;
713 }
714 
715 /* Allocate RX descriptor rings for the given receive queue */
716 static int emac_rx_descs_alloc(struct emac_adapter *adpt)
717 {
718 	struct emac_ring_header *ring_header = &adpt->ring_header;
719 	int node = dev_to_node(adpt->netdev->dev.parent);
720 	struct emac_rx_queue *rx_q = &adpt->rx_q;
721 	size_t size;
722 
723 	size = sizeof(struct emac_buffer) * rx_q->rfd.count;
724 	rx_q->rfd.rfbuff = kzalloc_node(size, GFP_KERNEL, node);
725 	if (!rx_q->rfd.rfbuff)
726 		return -ENOMEM;
727 
728 	rx_q->rrd.size = rx_q->rrd.count * (adpt->rrd_size * 4);
729 	rx_q->rfd.size = rx_q->rfd.count * (adpt->rfd_size * 4);
730 
731 	rx_q->rrd.dma_addr = ring_header->dma_addr + ring_header->used;
732 	rx_q->rrd.v_addr   = ring_header->v_addr + ring_header->used;
733 	ring_header->used += ALIGN(rx_q->rrd.size, 8);
734 
735 	rx_q->rfd.dma_addr = ring_header->dma_addr + ring_header->used;
736 	rx_q->rfd.v_addr   = ring_header->v_addr + ring_header->used;
737 	ring_header->used += ALIGN(rx_q->rfd.size, 8);
738 
739 	rx_q->rrd.produce_idx = 0;
740 	rx_q->rrd.consume_idx = 0;
741 
742 	rx_q->rfd.produce_idx = 0;
743 	rx_q->rfd.consume_idx = 0;
744 
745 	return 0;
746 }
747 
748 /* Allocate all TX and RX descriptor rings */
749 int emac_mac_rx_tx_rings_alloc_all(struct emac_adapter *adpt)
750 {
751 	struct emac_ring_header *ring_header = &adpt->ring_header;
752 	struct device *dev = adpt->netdev->dev.parent;
753 	unsigned int num_tx_descs = adpt->tx_desc_cnt;
754 	unsigned int num_rx_descs = adpt->rx_desc_cnt;
755 	int ret;
756 
757 	adpt->tx_q.tpd.count = adpt->tx_desc_cnt;
758 
759 	adpt->rx_q.rrd.count = adpt->rx_desc_cnt;
760 	adpt->rx_q.rfd.count = adpt->rx_desc_cnt;
761 
762 	/* Ring DMA buffer. Each ring may need up to 8 bytes for alignment,
763 	 * hence the additional padding bytes are allocated.
764 	 */
765 	ring_header->size = num_tx_descs * (adpt->tpd_size * 4) +
766 			    num_rx_descs * (adpt->rfd_size * 4) +
767 			    num_rx_descs * (adpt->rrd_size * 4) +
768 			    8 + 2 * 8; /* 8 byte per one Tx and two Rx rings */
769 
770 	ring_header->used = 0;
771 	ring_header->v_addr = dma_alloc_coherent(dev, ring_header->size,
772 						 &ring_header->dma_addr,
773 						 GFP_KERNEL);
774 	if (!ring_header->v_addr)
775 		return -ENOMEM;
776 
777 	ring_header->used = ALIGN(ring_header->dma_addr, 8) -
778 							ring_header->dma_addr;
779 
780 	ret = emac_tx_q_desc_alloc(adpt, &adpt->tx_q);
781 	if (ret) {
782 		netdev_err(adpt->netdev, "error: Tx Queue alloc failed\n");
783 		goto err_alloc_tx;
784 	}
785 
786 	ret = emac_rx_descs_alloc(adpt);
787 	if (ret) {
788 		netdev_err(adpt->netdev, "error: Rx Queue alloc failed\n");
789 		goto err_alloc_rx;
790 	}
791 
792 	return 0;
793 
794 err_alloc_rx:
795 	emac_tx_q_bufs_free(adpt);
796 err_alloc_tx:
797 	dma_free_coherent(dev, ring_header->size,
798 			  ring_header->v_addr, ring_header->dma_addr);
799 
800 	ring_header->v_addr   = NULL;
801 	ring_header->dma_addr = 0;
802 	ring_header->size     = 0;
803 	ring_header->used     = 0;
804 
805 	return ret;
806 }
807 
808 /* Free all TX and RX descriptor rings */
809 void emac_mac_rx_tx_rings_free_all(struct emac_adapter *adpt)
810 {
811 	struct emac_ring_header *ring_header = &adpt->ring_header;
812 	struct device *dev = adpt->netdev->dev.parent;
813 
814 	emac_tx_q_bufs_free(adpt);
815 	emac_rx_q_bufs_free(adpt);
816 
817 	dma_free_coherent(dev, ring_header->size,
818 			  ring_header->v_addr, ring_header->dma_addr);
819 
820 	ring_header->v_addr   = NULL;
821 	ring_header->dma_addr = 0;
822 	ring_header->size     = 0;
823 	ring_header->used     = 0;
824 }
825 
826 /* Initialize descriptor rings */
827 static void emac_mac_rx_tx_ring_reset_all(struct emac_adapter *adpt)
828 {
829 	unsigned int i;
830 
831 	adpt->tx_q.tpd.produce_idx = 0;
832 	adpt->tx_q.tpd.consume_idx = 0;
833 	for (i = 0; i < adpt->tx_q.tpd.count; i++)
834 		adpt->tx_q.tpd.tpbuff[i].dma_addr = 0;
835 
836 	adpt->rx_q.rrd.produce_idx = 0;
837 	adpt->rx_q.rrd.consume_idx = 0;
838 	adpt->rx_q.rfd.produce_idx = 0;
839 	adpt->rx_q.rfd.consume_idx = 0;
840 	for (i = 0; i < adpt->rx_q.rfd.count; i++)
841 		adpt->rx_q.rfd.rfbuff[i].dma_addr = 0;
842 }
843 
844 /* Produce new receive free descriptor */
845 static void emac_mac_rx_rfd_create(struct emac_adapter *adpt,
846 				   struct emac_rx_queue *rx_q,
847 				   dma_addr_t addr)
848 {
849 	u32 *hw_rfd = EMAC_RFD(rx_q, adpt->rfd_size, rx_q->rfd.produce_idx);
850 
851 	*(hw_rfd++) = lower_32_bits(addr);
852 	*hw_rfd = upper_32_bits(addr);
853 
854 	if (++rx_q->rfd.produce_idx == rx_q->rfd.count)
855 		rx_q->rfd.produce_idx = 0;
856 }
857 
858 /* Fill up receive queue's RFD with preallocated receive buffers */
859 static void emac_mac_rx_descs_refill(struct emac_adapter *adpt,
860 				    struct emac_rx_queue *rx_q)
861 {
862 	struct emac_buffer *curr_rxbuf;
863 	struct emac_buffer *next_rxbuf;
864 	unsigned int count = 0;
865 	u32 next_produce_idx;
866 
867 	next_produce_idx = rx_q->rfd.produce_idx + 1;
868 	if (next_produce_idx == rx_q->rfd.count)
869 		next_produce_idx = 0;
870 
871 	curr_rxbuf = GET_RFD_BUFFER(rx_q, rx_q->rfd.produce_idx);
872 	next_rxbuf = GET_RFD_BUFFER(rx_q, next_produce_idx);
873 
874 	/* this always has a blank rx_buffer*/
875 	while (!next_rxbuf->dma_addr) {
876 		struct sk_buff *skb;
877 		int ret;
878 
879 		skb = netdev_alloc_skb_ip_align(adpt->netdev, adpt->rxbuf_size);
880 		if (!skb)
881 			break;
882 
883 		curr_rxbuf->dma_addr =
884 			dma_map_single(adpt->netdev->dev.parent, skb->data,
885 				       adpt->rxbuf_size, DMA_FROM_DEVICE);
886 
887 		ret = dma_mapping_error(adpt->netdev->dev.parent,
888 					curr_rxbuf->dma_addr);
889 		if (ret) {
890 			dev_kfree_skb(skb);
891 			break;
892 		}
893 		curr_rxbuf->skb = skb;
894 		curr_rxbuf->length = adpt->rxbuf_size;
895 
896 		emac_mac_rx_rfd_create(adpt, rx_q, curr_rxbuf->dma_addr);
897 		next_produce_idx = rx_q->rfd.produce_idx + 1;
898 		if (next_produce_idx == rx_q->rfd.count)
899 			next_produce_idx = 0;
900 
901 		curr_rxbuf = GET_RFD_BUFFER(rx_q, rx_q->rfd.produce_idx);
902 		next_rxbuf = GET_RFD_BUFFER(rx_q, next_produce_idx);
903 		count++;
904 	}
905 
906 	if (count) {
907 		u32 prod_idx = (rx_q->rfd.produce_idx << rx_q->produce_shift) &
908 				rx_q->produce_mask;
909 		emac_reg_update32(adpt->base + rx_q->produce_reg,
910 				  rx_q->produce_mask, prod_idx);
911 	}
912 }
913 
914 static void emac_adjust_link(struct net_device *netdev)
915 {
916 	struct emac_adapter *adpt = netdev_priv(netdev);
917 	struct phy_device *phydev = netdev->phydev;
918 
919 	if (phydev->link) {
920 		emac_mac_start(adpt);
921 		emac_sgmii_link_change(adpt, true);
922 	} else {
923 		emac_sgmii_link_change(adpt, false);
924 		emac_mac_stop(adpt);
925 	}
926 
927 	phy_print_status(phydev);
928 }
929 
930 /* Bringup the interface/HW */
931 int emac_mac_up(struct emac_adapter *adpt)
932 {
933 	struct net_device *netdev = adpt->netdev;
934 	int ret;
935 
936 	emac_mac_rx_tx_ring_reset_all(adpt);
937 	emac_mac_config(adpt);
938 	emac_mac_rx_descs_refill(adpt, &adpt->rx_q);
939 
940 	adpt->phydev->irq = PHY_POLL;
941 	ret = phy_connect_direct(netdev, adpt->phydev, emac_adjust_link,
942 				 PHY_INTERFACE_MODE_SGMII);
943 	if (ret) {
944 		netdev_err(adpt->netdev, "could not connect phy\n");
945 		return ret;
946 	}
947 
948 	phy_attached_print(adpt->phydev, NULL);
949 
950 	/* enable mac irq */
951 	writel((u32)~DIS_INT, adpt->base + EMAC_INT_STATUS);
952 	writel(adpt->irq.mask, adpt->base + EMAC_INT_MASK);
953 
954 	phy_start(adpt->phydev);
955 
956 	napi_enable(&adpt->rx_q.napi);
957 	netif_start_queue(netdev);
958 
959 	return 0;
960 }
961 
962 /* Bring down the interface/HW */
963 void emac_mac_down(struct emac_adapter *adpt)
964 {
965 	struct net_device *netdev = adpt->netdev;
966 
967 	netif_stop_queue(netdev);
968 	napi_disable(&adpt->rx_q.napi);
969 
970 	phy_stop(adpt->phydev);
971 
972 	/* Interrupts must be disabled before the PHY is disconnected, to
973 	 * avoid a race condition where adjust_link is null when we get
974 	 * an interrupt.
975 	 */
976 	writel(DIS_INT, adpt->base + EMAC_INT_STATUS);
977 	writel(0, adpt->base + EMAC_INT_MASK);
978 	synchronize_irq(adpt->irq.irq);
979 
980 	phy_disconnect(adpt->phydev);
981 
982 	emac_mac_reset(adpt);
983 
984 	emac_tx_q_descs_free(adpt);
985 	netdev_reset_queue(adpt->netdev);
986 	emac_rx_q_free_descs(adpt);
987 }
988 
989 /* Consume next received packet descriptor */
990 static bool emac_rx_process_rrd(struct emac_adapter *adpt,
991 				struct emac_rx_queue *rx_q,
992 				struct emac_rrd *rrd)
993 {
994 	u32 *hw_rrd = EMAC_RRD(rx_q, adpt->rrd_size, rx_q->rrd.consume_idx);
995 
996 	rrd->word[3] = *(hw_rrd + 3);
997 
998 	if (!RRD_UPDT(rrd))
999 		return false;
1000 
1001 	rrd->word[4] = 0;
1002 	rrd->word[5] = 0;
1003 
1004 	rrd->word[0] = *(hw_rrd++);
1005 	rrd->word[1] = *(hw_rrd++);
1006 	rrd->word[2] = *(hw_rrd++);
1007 
1008 	if (unlikely(RRD_NOR(rrd) != 1)) {
1009 		netdev_err(adpt->netdev,
1010 			   "error: multi-RFD not support yet! nor:%lu\n",
1011 			   RRD_NOR(rrd));
1012 	}
1013 
1014 	/* mark rrd as processed */
1015 	RRD_UPDT_SET(rrd, 0);
1016 	*hw_rrd = rrd->word[3];
1017 
1018 	if (++rx_q->rrd.consume_idx == rx_q->rrd.count)
1019 		rx_q->rrd.consume_idx = 0;
1020 
1021 	return true;
1022 }
1023 
1024 /* Produce new transmit descriptor */
1025 static void emac_tx_tpd_create(struct emac_adapter *adpt,
1026 			       struct emac_tx_queue *tx_q, struct emac_tpd *tpd)
1027 {
1028 	u32 *hw_tpd;
1029 
1030 	tx_q->tpd.last_produce_idx = tx_q->tpd.produce_idx;
1031 	hw_tpd = EMAC_TPD(tx_q, adpt->tpd_size, tx_q->tpd.produce_idx);
1032 
1033 	if (++tx_q->tpd.produce_idx == tx_q->tpd.count)
1034 		tx_q->tpd.produce_idx = 0;
1035 
1036 	*(hw_tpd++) = tpd->word[0];
1037 	*(hw_tpd++) = tpd->word[1];
1038 	*(hw_tpd++) = tpd->word[2];
1039 	*hw_tpd = tpd->word[3];
1040 }
1041 
1042 /* Mark the last transmit descriptor as such (for the transmit packet) */
1043 static void emac_tx_tpd_mark_last(struct emac_adapter *adpt,
1044 				  struct emac_tx_queue *tx_q)
1045 {
1046 	u32 *hw_tpd =
1047 		EMAC_TPD(tx_q, adpt->tpd_size, tx_q->tpd.last_produce_idx);
1048 	u32 tmp_tpd;
1049 
1050 	tmp_tpd = *(hw_tpd + 1);
1051 	tmp_tpd |= EMAC_TPD_LAST_FRAGMENT;
1052 	*(hw_tpd + 1) = tmp_tpd;
1053 }
1054 
1055 static void emac_rx_rfd_clean(struct emac_rx_queue *rx_q, struct emac_rrd *rrd)
1056 {
1057 	struct emac_buffer *rfbuf = rx_q->rfd.rfbuff;
1058 	u32 consume_idx = RRD_SI(rrd);
1059 	unsigned int i;
1060 
1061 	for (i = 0; i < RRD_NOR(rrd); i++) {
1062 		rfbuf[consume_idx].skb = NULL;
1063 		if (++consume_idx == rx_q->rfd.count)
1064 			consume_idx = 0;
1065 	}
1066 
1067 	rx_q->rfd.consume_idx = consume_idx;
1068 	rx_q->rfd.process_idx = consume_idx;
1069 }
1070 
1071 /* Push the received skb to upper layers */
1072 static void emac_receive_skb(struct emac_rx_queue *rx_q,
1073 			     struct sk_buff *skb,
1074 			     u16 vlan_tag, bool vlan_flag)
1075 {
1076 	if (vlan_flag) {
1077 		u16 vlan;
1078 
1079 		EMAC_TAG_TO_VLAN(vlan_tag, vlan);
1080 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan);
1081 	}
1082 
1083 	napi_gro_receive(&rx_q->napi, skb);
1084 }
1085 
1086 /* Process receive event */
1087 void emac_mac_rx_process(struct emac_adapter *adpt, struct emac_rx_queue *rx_q,
1088 			 int *num_pkts, int max_pkts)
1089 {
1090 	u32 proc_idx, hw_consume_idx, num_consume_pkts;
1091 	struct net_device *netdev  = adpt->netdev;
1092 	struct emac_buffer *rfbuf;
1093 	unsigned int count = 0;
1094 	struct emac_rrd rrd;
1095 	struct sk_buff *skb;
1096 	u32 reg;
1097 
1098 	reg = readl_relaxed(adpt->base + rx_q->consume_reg);
1099 
1100 	hw_consume_idx = (reg & rx_q->consume_mask) >> rx_q->consume_shift;
1101 	num_consume_pkts = (hw_consume_idx >= rx_q->rrd.consume_idx) ?
1102 		(hw_consume_idx -  rx_q->rrd.consume_idx) :
1103 		(hw_consume_idx + rx_q->rrd.count - rx_q->rrd.consume_idx);
1104 
1105 	do {
1106 		if (!num_consume_pkts)
1107 			break;
1108 
1109 		if (!emac_rx_process_rrd(adpt, rx_q, &rrd))
1110 			break;
1111 
1112 		if (likely(RRD_NOR(&rrd) == 1)) {
1113 			/* good receive */
1114 			rfbuf = GET_RFD_BUFFER(rx_q, RRD_SI(&rrd));
1115 			dma_unmap_single(adpt->netdev->dev.parent,
1116 					 rfbuf->dma_addr, rfbuf->length,
1117 					 DMA_FROM_DEVICE);
1118 			rfbuf->dma_addr = 0;
1119 			skb = rfbuf->skb;
1120 		} else {
1121 			netdev_err(adpt->netdev,
1122 				   "error: multi-RFD not support yet!\n");
1123 			break;
1124 		}
1125 		emac_rx_rfd_clean(rx_q, &rrd);
1126 		num_consume_pkts--;
1127 		count++;
1128 
1129 		/* Due to a HW issue in L4 check sum detection (UDP/TCP frags
1130 		 * with DF set are marked as error), drop packets based on the
1131 		 * error mask rather than the summary bit (ignoring L4F errors)
1132 		 */
1133 		if (rrd.word[EMAC_RRD_STATS_DW_IDX] & EMAC_RRD_ERROR) {
1134 			netif_dbg(adpt, rx_status, adpt->netdev,
1135 				  "Drop error packet[RRD: 0x%x:0x%x:0x%x:0x%x]\n",
1136 				  rrd.word[0], rrd.word[1],
1137 				  rrd.word[2], rrd.word[3]);
1138 
1139 			dev_kfree_skb(skb);
1140 			continue;
1141 		}
1142 
1143 		skb_put(skb, RRD_PKT_SIZE(&rrd) - ETH_FCS_LEN);
1144 		skb->dev = netdev;
1145 		skb->protocol = eth_type_trans(skb, skb->dev);
1146 		if (netdev->features & NETIF_F_RXCSUM)
1147 			skb->ip_summed = RRD_L4F(&rrd) ?
1148 					  CHECKSUM_NONE : CHECKSUM_UNNECESSARY;
1149 		else
1150 			skb_checksum_none_assert(skb);
1151 
1152 		emac_receive_skb(rx_q, skb, (u16)RRD_CVALN_TAG(&rrd),
1153 				 (bool)RRD_CVTAG(&rrd));
1154 
1155 		(*num_pkts)++;
1156 	} while (*num_pkts < max_pkts);
1157 
1158 	if (count) {
1159 		proc_idx = (rx_q->rfd.process_idx << rx_q->process_shft) &
1160 				rx_q->process_mask;
1161 		emac_reg_update32(adpt->base + rx_q->process_reg,
1162 				  rx_q->process_mask, proc_idx);
1163 		emac_mac_rx_descs_refill(adpt, rx_q);
1164 	}
1165 }
1166 
1167 /* get the number of free transmit descriptors */
1168 static unsigned int emac_tpd_num_free_descs(struct emac_tx_queue *tx_q)
1169 {
1170 	u32 produce_idx = tx_q->tpd.produce_idx;
1171 	u32 consume_idx = tx_q->tpd.consume_idx;
1172 
1173 	return (consume_idx > produce_idx) ?
1174 		(consume_idx - produce_idx - 1) :
1175 		(tx_q->tpd.count + consume_idx - produce_idx - 1);
1176 }
1177 
1178 /* Process transmit event */
1179 void emac_mac_tx_process(struct emac_adapter *adpt, struct emac_tx_queue *tx_q)
1180 {
1181 	u32 reg = readl_relaxed(adpt->base + tx_q->consume_reg);
1182 	u32 hw_consume_idx, pkts_compl = 0, bytes_compl = 0;
1183 	struct emac_buffer *tpbuf;
1184 
1185 	hw_consume_idx = (reg & tx_q->consume_mask) >> tx_q->consume_shift;
1186 
1187 	while (tx_q->tpd.consume_idx != hw_consume_idx) {
1188 		tpbuf = GET_TPD_BUFFER(tx_q, tx_q->tpd.consume_idx);
1189 		if (tpbuf->dma_addr) {
1190 			dma_unmap_page(adpt->netdev->dev.parent,
1191 				       tpbuf->dma_addr, tpbuf->length,
1192 				       DMA_TO_DEVICE);
1193 			tpbuf->dma_addr = 0;
1194 		}
1195 
1196 		if (tpbuf->skb) {
1197 			pkts_compl++;
1198 			bytes_compl += tpbuf->skb->len;
1199 			dev_consume_skb_irq(tpbuf->skb);
1200 			tpbuf->skb = NULL;
1201 		}
1202 
1203 		if (++tx_q->tpd.consume_idx == tx_q->tpd.count)
1204 			tx_q->tpd.consume_idx = 0;
1205 	}
1206 
1207 	netdev_completed_queue(adpt->netdev, pkts_compl, bytes_compl);
1208 
1209 	if (netif_queue_stopped(adpt->netdev))
1210 		if (emac_tpd_num_free_descs(tx_q) > (MAX_SKB_FRAGS + 1))
1211 			netif_wake_queue(adpt->netdev);
1212 }
1213 
1214 /* Initialize all queue data structures */
1215 void emac_mac_rx_tx_ring_init_all(struct platform_device *pdev,
1216 				  struct emac_adapter *adpt)
1217 {
1218 	adpt->rx_q.netdev = adpt->netdev;
1219 
1220 	adpt->rx_q.produce_reg  = EMAC_MAILBOX_0;
1221 	adpt->rx_q.produce_mask = RFD0_PROD_IDX_BMSK;
1222 	adpt->rx_q.produce_shift = RFD0_PROD_IDX_SHFT;
1223 
1224 	adpt->rx_q.process_reg  = EMAC_MAILBOX_0;
1225 	adpt->rx_q.process_mask = RFD0_PROC_IDX_BMSK;
1226 	adpt->rx_q.process_shft = RFD0_PROC_IDX_SHFT;
1227 
1228 	adpt->rx_q.consume_reg  = EMAC_MAILBOX_3;
1229 	adpt->rx_q.consume_mask = RFD0_CONS_IDX_BMSK;
1230 	adpt->rx_q.consume_shift = RFD0_CONS_IDX_SHFT;
1231 
1232 	adpt->rx_q.irq          = &adpt->irq;
1233 	adpt->rx_q.intr         = adpt->irq.mask & ISR_RX_PKT;
1234 
1235 	adpt->tx_q.produce_reg  = EMAC_MAILBOX_15;
1236 	adpt->tx_q.produce_mask = NTPD_PROD_IDX_BMSK;
1237 	adpt->tx_q.produce_shift = NTPD_PROD_IDX_SHFT;
1238 
1239 	adpt->tx_q.consume_reg  = EMAC_MAILBOX_2;
1240 	adpt->tx_q.consume_mask = NTPD_CONS_IDX_BMSK;
1241 	adpt->tx_q.consume_shift = NTPD_CONS_IDX_SHFT;
1242 }
1243 
1244 /* Fill up transmit descriptors with TSO and Checksum offload information */
1245 static int emac_tso_csum(struct emac_adapter *adpt,
1246 			 struct emac_tx_queue *tx_q,
1247 			 struct sk_buff *skb,
1248 			 struct emac_tpd *tpd)
1249 {
1250 	unsigned int hdr_len;
1251 	int ret;
1252 
1253 	if (skb_is_gso(skb)) {
1254 		if (skb_header_cloned(skb)) {
1255 			ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
1256 			if (unlikely(ret))
1257 				return ret;
1258 		}
1259 
1260 		if (skb->protocol == htons(ETH_P_IP)) {
1261 			u32 pkt_len = ((unsigned char *)ip_hdr(skb) - skb->data)
1262 				       + ntohs(ip_hdr(skb)->tot_len);
1263 			if (skb->len > pkt_len)
1264 				pskb_trim(skb, pkt_len);
1265 		}
1266 
1267 		hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
1268 		if (unlikely(skb->len == hdr_len)) {
1269 			/* we only need to do csum */
1270 			netif_warn(adpt, tx_err, adpt->netdev,
1271 				   "tso not needed for packet with 0 data\n");
1272 			goto do_csum;
1273 		}
1274 
1275 		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
1276 			ip_hdr(skb)->check = 0;
1277 			tcp_hdr(skb)->check =
1278 				~csum_tcpudp_magic(ip_hdr(skb)->saddr,
1279 						   ip_hdr(skb)->daddr,
1280 						   0, IPPROTO_TCP, 0);
1281 			TPD_IPV4_SET(tpd, 1);
1282 		}
1283 
1284 		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) {
1285 			/* ipv6 tso need an extra tpd */
1286 			struct emac_tpd extra_tpd;
1287 
1288 			memset(tpd, 0, sizeof(*tpd));
1289 			memset(&extra_tpd, 0, sizeof(extra_tpd));
1290 
1291 			tcp_v6_gso_csum_prep(skb);
1292 
1293 			TPD_PKT_LEN_SET(&extra_tpd, skb->len);
1294 			TPD_LSO_SET(&extra_tpd, 1);
1295 			TPD_LSOV_SET(&extra_tpd, 1);
1296 			emac_tx_tpd_create(adpt, tx_q, &extra_tpd);
1297 			TPD_LSOV_SET(tpd, 1);
1298 		}
1299 
1300 		TPD_LSO_SET(tpd, 1);
1301 		TPD_TCPHDR_OFFSET_SET(tpd, skb_transport_offset(skb));
1302 		TPD_MSS_SET(tpd, skb_shinfo(skb)->gso_size);
1303 		return 0;
1304 	}
1305 
1306 do_csum:
1307 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
1308 		unsigned int css, cso;
1309 
1310 		cso = skb_transport_offset(skb);
1311 		if (unlikely(cso & 0x1)) {
1312 			netdev_err(adpt->netdev,
1313 				   "error: payload offset should be even\n");
1314 			return -EINVAL;
1315 		}
1316 		css = cso + skb->csum_offset;
1317 
1318 		TPD_PAYLOAD_OFFSET_SET(tpd, cso >> 1);
1319 		TPD_CXSUM_OFFSET_SET(tpd, css >> 1);
1320 		TPD_CSX_SET(tpd, 1);
1321 	}
1322 
1323 	return 0;
1324 }
1325 
1326 /* Fill up transmit descriptors */
1327 static void emac_tx_fill_tpd(struct emac_adapter *adpt,
1328 			     struct emac_tx_queue *tx_q, struct sk_buff *skb,
1329 			     struct emac_tpd *tpd)
1330 {
1331 	unsigned int nr_frags = skb_shinfo(skb)->nr_frags;
1332 	unsigned int first = tx_q->tpd.produce_idx;
1333 	unsigned int len = skb_headlen(skb);
1334 	struct emac_buffer *tpbuf = NULL;
1335 	unsigned int mapped_len = 0;
1336 	unsigned int i;
1337 	int count = 0;
1338 	int ret;
1339 
1340 	/* if Large Segment Offload is (in TCP Segmentation Offload struct) */
1341 	if (TPD_LSO(tpd)) {
1342 		mapped_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
1343 
1344 		tpbuf = GET_TPD_BUFFER(tx_q, tx_q->tpd.produce_idx);
1345 		tpbuf->length = mapped_len;
1346 		tpbuf->dma_addr = dma_map_page(adpt->netdev->dev.parent,
1347 					       virt_to_page(skb->data),
1348 					       offset_in_page(skb->data),
1349 					       tpbuf->length,
1350 					       DMA_TO_DEVICE);
1351 		ret = dma_mapping_error(adpt->netdev->dev.parent,
1352 					tpbuf->dma_addr);
1353 		if (ret)
1354 			goto error;
1355 
1356 		TPD_BUFFER_ADDR_L_SET(tpd, lower_32_bits(tpbuf->dma_addr));
1357 		TPD_BUFFER_ADDR_H_SET(tpd, upper_32_bits(tpbuf->dma_addr));
1358 		TPD_BUF_LEN_SET(tpd, tpbuf->length);
1359 		emac_tx_tpd_create(adpt, tx_q, tpd);
1360 		count++;
1361 	}
1362 
1363 	if (mapped_len < len) {
1364 		tpbuf = GET_TPD_BUFFER(tx_q, tx_q->tpd.produce_idx);
1365 		tpbuf->length = len - mapped_len;
1366 		tpbuf->dma_addr = dma_map_page(adpt->netdev->dev.parent,
1367 					       virt_to_page(skb->data +
1368 							    mapped_len),
1369 					       offset_in_page(skb->data +
1370 							      mapped_len),
1371 					       tpbuf->length, DMA_TO_DEVICE);
1372 		ret = dma_mapping_error(adpt->netdev->dev.parent,
1373 					tpbuf->dma_addr);
1374 		if (ret)
1375 			goto error;
1376 
1377 		TPD_BUFFER_ADDR_L_SET(tpd, lower_32_bits(tpbuf->dma_addr));
1378 		TPD_BUFFER_ADDR_H_SET(tpd, upper_32_bits(tpbuf->dma_addr));
1379 		TPD_BUF_LEN_SET(tpd, tpbuf->length);
1380 		emac_tx_tpd_create(adpt, tx_q, tpd);
1381 		count++;
1382 	}
1383 
1384 	for (i = 0; i < nr_frags; i++) {
1385 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1386 
1387 		tpbuf = GET_TPD_BUFFER(tx_q, tx_q->tpd.produce_idx);
1388 		tpbuf->length = skb_frag_size(frag);
1389 		tpbuf->dma_addr = skb_frag_dma_map(adpt->netdev->dev.parent,
1390 						   frag, 0, tpbuf->length,
1391 						   DMA_TO_DEVICE);
1392 		ret = dma_mapping_error(adpt->netdev->dev.parent,
1393 					tpbuf->dma_addr);
1394 		if (ret)
1395 			goto error;
1396 
1397 		TPD_BUFFER_ADDR_L_SET(tpd, lower_32_bits(tpbuf->dma_addr));
1398 		TPD_BUFFER_ADDR_H_SET(tpd, upper_32_bits(tpbuf->dma_addr));
1399 		TPD_BUF_LEN_SET(tpd, tpbuf->length);
1400 		emac_tx_tpd_create(adpt, tx_q, tpd);
1401 		count++;
1402 	}
1403 
1404 	/* The last tpd */
1405 	wmb();
1406 	emac_tx_tpd_mark_last(adpt, tx_q);
1407 
1408 	/* The last buffer info contain the skb address,
1409 	 * so it will be freed after unmap
1410 	 */
1411 	tpbuf->skb = skb;
1412 
1413 	return;
1414 
1415 error:
1416 	/* One of the memory mappings failed, so undo everything */
1417 	tx_q->tpd.produce_idx = first;
1418 
1419 	while (count--) {
1420 		tpbuf = GET_TPD_BUFFER(tx_q, first);
1421 		dma_unmap_page(adpt->netdev->dev.parent, tpbuf->dma_addr,
1422 			       tpbuf->length, DMA_TO_DEVICE);
1423 		tpbuf->dma_addr = 0;
1424 		tpbuf->length = 0;
1425 
1426 		if (++first == tx_q->tpd.count)
1427 			first = 0;
1428 	}
1429 
1430 	dev_kfree_skb(skb);
1431 }
1432 
1433 /* Transmit the packet using specified transmit queue */
1434 netdev_tx_t emac_mac_tx_buf_send(struct emac_adapter *adpt,
1435 				 struct emac_tx_queue *tx_q,
1436 				 struct sk_buff *skb)
1437 {
1438 	struct emac_tpd tpd;
1439 	u32 prod_idx;
1440 	int len;
1441 
1442 	memset(&tpd, 0, sizeof(tpd));
1443 
1444 	if (emac_tso_csum(adpt, tx_q, skb, &tpd) != 0) {
1445 		dev_kfree_skb_any(skb);
1446 		return NETDEV_TX_OK;
1447 	}
1448 
1449 	if (skb_vlan_tag_present(skb)) {
1450 		u16 tag;
1451 
1452 		EMAC_VLAN_TO_TAG(skb_vlan_tag_get(skb), tag);
1453 		TPD_CVLAN_TAG_SET(&tpd, tag);
1454 		TPD_INSTC_SET(&tpd, 1);
1455 	}
1456 
1457 	if (skb_network_offset(skb) != ETH_HLEN)
1458 		TPD_TYP_SET(&tpd, 1);
1459 
1460 	len = skb->len;
1461 	emac_tx_fill_tpd(adpt, tx_q, skb, &tpd);
1462 
1463 	netdev_sent_queue(adpt->netdev, len);
1464 
1465 	/* Make sure the are enough free descriptors to hold one
1466 	 * maximum-sized SKB.  We need one desc for each fragment,
1467 	 * one for the checksum (emac_tso_csum), one for TSO, and
1468 	 * one for the SKB header.
1469 	 */
1470 	if (emac_tpd_num_free_descs(tx_q) < (MAX_SKB_FRAGS + 3))
1471 		netif_stop_queue(adpt->netdev);
1472 
1473 	/* update produce idx */
1474 	prod_idx = (tx_q->tpd.produce_idx << tx_q->produce_shift) &
1475 		    tx_q->produce_mask;
1476 	emac_reg_update32(adpt->base + tx_q->produce_reg,
1477 			  tx_q->produce_mask, prod_idx);
1478 
1479 	return NETDEV_TX_OK;
1480 }
1481