xref: /openbmc/linux/drivers/usb/host/xhci-mtk-sch.c (revision 9dbbc3b9)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2015 MediaTek Inc.
4  * Author:
5  *  Zhigang.Wei <zhigang.wei@mediatek.com>
6  *  Chunfeng.Yun <chunfeng.yun@mediatek.com>
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 
13 #include "xhci.h"
14 #include "xhci-mtk.h"
15 
16 #define SSP_BW_BOUNDARY	130000
17 #define SS_BW_BOUNDARY	51000
18 /* table 5-5. High-speed Isoc Transaction Limits in usb_20 spec */
19 #define HS_BW_BOUNDARY	6144
20 /* usb2 spec section11.18.1: at most 188 FS bytes per microframe */
21 #define FS_PAYLOAD_MAX 188
22 /*
23  * max number of microframes for split transfer,
24  * for fs isoc in : 1 ss + 1 idle + 7 cs
25  */
26 #define TT_MICROFRAMES_MAX 9
27 
28 #define DBG_BUF_EN	64
29 
30 /* schedule error type */
31 #define ESCH_SS_Y6		1001
32 #define ESCH_SS_OVERLAP		1002
33 #define ESCH_CS_OVERFLOW	1003
34 #define ESCH_BW_OVERFLOW	1004
35 #define ESCH_FIXME		1005
36 
37 /* mtk scheduler bitmasks */
38 #define EP_BPKTS(p)	((p) & 0x7f)
39 #define EP_BCSCOUNT(p)	(((p) & 0x7) << 8)
40 #define EP_BBM(p)	((p) << 11)
41 #define EP_BOFFSET(p)	((p) & 0x3fff)
42 #define EP_BREPEAT(p)	(((p) & 0x7fff) << 16)
43 
44 static char *sch_error_string(int err_num)
45 {
46 	switch (err_num) {
47 	case ESCH_SS_Y6:
48 		return "Can't schedule Start-Split in Y6";
49 	case ESCH_SS_OVERLAP:
50 		return "Can't find a suitable Start-Split location";
51 	case ESCH_CS_OVERFLOW:
52 		return "The last Complete-Split is greater than 7";
53 	case ESCH_BW_OVERFLOW:
54 		return "Bandwidth exceeds the maximum limit";
55 	case ESCH_FIXME:
56 		return "FIXME, to be resolved";
57 	default:
58 		return "Unknown";
59 	}
60 }
61 
62 static int is_fs_or_ls(enum usb_device_speed speed)
63 {
64 	return speed == USB_SPEED_FULL || speed == USB_SPEED_LOW;
65 }
66 
67 static const char *
68 decode_ep(struct usb_host_endpoint *ep, enum usb_device_speed speed)
69 {
70 	static char buf[DBG_BUF_EN];
71 	struct usb_endpoint_descriptor *epd = &ep->desc;
72 	unsigned int interval;
73 	const char *unit;
74 
75 	interval = usb_decode_interval(epd, speed);
76 	if (interval % 1000) {
77 		unit = "us";
78 	} else {
79 		unit = "ms";
80 		interval /= 1000;
81 	}
82 
83 	snprintf(buf, DBG_BUF_EN, "%s ep%d%s %s, mpkt:%d, interval:%d/%d%s\n",
84 		 usb_speed_string(speed), usb_endpoint_num(epd),
85 		 usb_endpoint_dir_in(epd) ? "in" : "out",
86 		 usb_ep_type_string(usb_endpoint_type(epd)),
87 		 usb_endpoint_maxp(epd), epd->bInterval, interval, unit);
88 
89 	return buf;
90 }
91 
92 static u32 get_bw_boundary(enum usb_device_speed speed)
93 {
94 	u32 boundary;
95 
96 	switch (speed) {
97 	case USB_SPEED_SUPER_PLUS:
98 		boundary = SSP_BW_BOUNDARY;
99 		break;
100 	case USB_SPEED_SUPER:
101 		boundary = SS_BW_BOUNDARY;
102 		break;
103 	default:
104 		boundary = HS_BW_BOUNDARY;
105 		break;
106 	}
107 
108 	return boundary;
109 }
110 
111 /*
112 * get the bandwidth domain which @ep belongs to.
113 *
114 * the bandwidth domain array is saved to @sch_array of struct xhci_hcd_mtk,
115 * each HS root port is treated as a single bandwidth domain,
116 * but each SS root port is treated as two bandwidth domains, one for IN eps,
117 * one for OUT eps.
118 * @real_port value is defined as follow according to xHCI spec:
119 * 1 for SSport0, ..., N+1 for SSportN, N+2 for HSport0, N+3 for HSport1, etc
120 * so the bandwidth domain array is organized as follow for simplification:
121 * SSport0-OUT, SSport0-IN, ..., SSportX-OUT, SSportX-IN, HSport0, ..., HSportY
122 */
123 static struct mu3h_sch_bw_info *
124 get_bw_info(struct xhci_hcd_mtk *mtk, struct usb_device *udev,
125 	    struct usb_host_endpoint *ep)
126 {
127 	struct xhci_hcd *xhci = hcd_to_xhci(mtk->hcd);
128 	struct xhci_virt_device *virt_dev;
129 	int bw_index;
130 
131 	virt_dev = xhci->devs[udev->slot_id];
132 
133 	if (udev->speed >= USB_SPEED_SUPER) {
134 		if (usb_endpoint_dir_out(&ep->desc))
135 			bw_index = (virt_dev->real_port - 1) * 2;
136 		else
137 			bw_index = (virt_dev->real_port - 1) * 2 + 1;
138 	} else {
139 		/* add one more for each SS port */
140 		bw_index = virt_dev->real_port + xhci->usb3_rhub.num_ports - 1;
141 	}
142 
143 	return &mtk->sch_array[bw_index];
144 }
145 
146 static u32 get_esit(struct xhci_ep_ctx *ep_ctx)
147 {
148 	u32 esit;
149 
150 	esit = 1 << CTX_TO_EP_INTERVAL(le32_to_cpu(ep_ctx->ep_info));
151 	if (esit > XHCI_MTK_MAX_ESIT)
152 		esit = XHCI_MTK_MAX_ESIT;
153 
154 	return esit;
155 }
156 
157 static struct mu3h_sch_tt *find_tt(struct usb_device *udev)
158 {
159 	struct usb_tt *utt = udev->tt;
160 	struct mu3h_sch_tt *tt, **tt_index, **ptt;
161 	bool allocated_index = false;
162 
163 	if (!utt)
164 		return NULL;	/* Not below a TT */
165 
166 	/*
167 	 * Find/create our data structure.
168 	 * For hubs with a single TT, we get it directly.
169 	 * For hubs with multiple TTs, there's an extra level of pointers.
170 	 */
171 	tt_index = NULL;
172 	if (utt->multi) {
173 		tt_index = utt->hcpriv;
174 		if (!tt_index) {	/* Create the index array */
175 			tt_index = kcalloc(utt->hub->maxchild,
176 					sizeof(*tt_index), GFP_KERNEL);
177 			if (!tt_index)
178 				return ERR_PTR(-ENOMEM);
179 			utt->hcpriv = tt_index;
180 			allocated_index = true;
181 		}
182 		ptt = &tt_index[udev->ttport - 1];
183 	} else {
184 		ptt = (struct mu3h_sch_tt **) &utt->hcpriv;
185 	}
186 
187 	tt = *ptt;
188 	if (!tt) {	/* Create the mu3h_sch_tt */
189 		tt = kzalloc(sizeof(*tt), GFP_KERNEL);
190 		if (!tt) {
191 			if (allocated_index) {
192 				utt->hcpriv = NULL;
193 				kfree(tt_index);
194 			}
195 			return ERR_PTR(-ENOMEM);
196 		}
197 		INIT_LIST_HEAD(&tt->ep_list);
198 		*ptt = tt;
199 	}
200 
201 	return tt;
202 }
203 
204 /* Release the TT above udev, if it's not in use */
205 static void drop_tt(struct usb_device *udev)
206 {
207 	struct usb_tt *utt = udev->tt;
208 	struct mu3h_sch_tt *tt, **tt_index, **ptt;
209 	int i, cnt;
210 
211 	if (!utt || !utt->hcpriv)
212 		return;		/* Not below a TT, or never allocated */
213 
214 	cnt = 0;
215 	if (utt->multi) {
216 		tt_index = utt->hcpriv;
217 		ptt = &tt_index[udev->ttport - 1];
218 		/*  How many entries are left in tt_index? */
219 		for (i = 0; i < utt->hub->maxchild; ++i)
220 			cnt += !!tt_index[i];
221 	} else {
222 		tt_index = NULL;
223 		ptt = (struct mu3h_sch_tt **)&utt->hcpriv;
224 	}
225 
226 	tt = *ptt;
227 	if (!tt || !list_empty(&tt->ep_list))
228 		return;		/* never allocated , or still in use*/
229 
230 	*ptt = NULL;
231 	kfree(tt);
232 
233 	if (cnt == 1) {
234 		utt->hcpriv = NULL;
235 		kfree(tt_index);
236 	}
237 }
238 
239 static struct mu3h_sch_ep_info *create_sch_ep(struct usb_device *udev,
240 	struct usb_host_endpoint *ep, struct xhci_ep_ctx *ep_ctx)
241 {
242 	struct mu3h_sch_ep_info *sch_ep;
243 	struct mu3h_sch_tt *tt = NULL;
244 	u32 len_bw_budget_table;
245 	size_t mem_size;
246 
247 	if (is_fs_or_ls(udev->speed))
248 		len_bw_budget_table = TT_MICROFRAMES_MAX;
249 	else if ((udev->speed >= USB_SPEED_SUPER)
250 			&& usb_endpoint_xfer_isoc(&ep->desc))
251 		len_bw_budget_table = get_esit(ep_ctx);
252 	else
253 		len_bw_budget_table = 1;
254 
255 	mem_size = sizeof(struct mu3h_sch_ep_info) +
256 			len_bw_budget_table * sizeof(u32);
257 	sch_ep = kzalloc(mem_size, GFP_KERNEL);
258 	if (!sch_ep)
259 		return ERR_PTR(-ENOMEM);
260 
261 	if (is_fs_or_ls(udev->speed)) {
262 		tt = find_tt(udev);
263 		if (IS_ERR(tt)) {
264 			kfree(sch_ep);
265 			return ERR_PTR(-ENOMEM);
266 		}
267 	}
268 
269 	sch_ep->sch_tt = tt;
270 	sch_ep->ep = ep;
271 	sch_ep->speed = udev->speed;
272 	INIT_LIST_HEAD(&sch_ep->endpoint);
273 	INIT_LIST_HEAD(&sch_ep->tt_endpoint);
274 
275 	return sch_ep;
276 }
277 
278 static void setup_sch_info(struct xhci_ep_ctx *ep_ctx,
279 			   struct mu3h_sch_ep_info *sch_ep)
280 {
281 	u32 ep_type;
282 	u32 maxpkt;
283 	u32 max_burst;
284 	u32 mult;
285 	u32 esit_pkts;
286 	u32 max_esit_payload;
287 	u32 *bwb_table = sch_ep->bw_budget_table;
288 	int i;
289 
290 	ep_type = CTX_TO_EP_TYPE(le32_to_cpu(ep_ctx->ep_info2));
291 	maxpkt = MAX_PACKET_DECODED(le32_to_cpu(ep_ctx->ep_info2));
292 	max_burst = CTX_TO_MAX_BURST(le32_to_cpu(ep_ctx->ep_info2));
293 	mult = CTX_TO_EP_MULT(le32_to_cpu(ep_ctx->ep_info));
294 	max_esit_payload =
295 		(CTX_TO_MAX_ESIT_PAYLOAD_HI(
296 			le32_to_cpu(ep_ctx->ep_info)) << 16) |
297 		 CTX_TO_MAX_ESIT_PAYLOAD(le32_to_cpu(ep_ctx->tx_info));
298 
299 	sch_ep->esit = get_esit(ep_ctx);
300 	sch_ep->ep_type = ep_type;
301 	sch_ep->maxpkt = maxpkt;
302 	sch_ep->offset = 0;
303 	sch_ep->burst_mode = 0;
304 	sch_ep->repeat = 0;
305 
306 	if (sch_ep->speed == USB_SPEED_HIGH) {
307 		sch_ep->cs_count = 0;
308 
309 		/*
310 		 * usb_20 spec section5.9
311 		 * a single microframe is enough for HS synchromous endpoints
312 		 * in a interval
313 		 */
314 		sch_ep->num_budget_microframes = 1;
315 
316 		/*
317 		 * xHCI spec section6.2.3.4
318 		 * @max_burst is the number of additional transactions
319 		 * opportunities per microframe
320 		 */
321 		sch_ep->pkts = max_burst + 1;
322 		sch_ep->bw_cost_per_microframe = maxpkt * sch_ep->pkts;
323 		bwb_table[0] = sch_ep->bw_cost_per_microframe;
324 	} else if (sch_ep->speed >= USB_SPEED_SUPER) {
325 		/* usb3_r1 spec section4.4.7 & 4.4.8 */
326 		sch_ep->cs_count = 0;
327 		sch_ep->burst_mode = 1;
328 		/*
329 		 * some device's (d)wBytesPerInterval is set as 0,
330 		 * then max_esit_payload is 0, so evaluate esit_pkts from
331 		 * mult and burst
332 		 */
333 		esit_pkts = DIV_ROUND_UP(max_esit_payload, maxpkt);
334 		if (esit_pkts == 0)
335 			esit_pkts = (mult + 1) * (max_burst + 1);
336 
337 		if (ep_type == INT_IN_EP || ep_type == INT_OUT_EP) {
338 			sch_ep->pkts = esit_pkts;
339 			sch_ep->num_budget_microframes = 1;
340 			bwb_table[0] = maxpkt * sch_ep->pkts;
341 		}
342 
343 		if (ep_type == ISOC_IN_EP || ep_type == ISOC_OUT_EP) {
344 
345 			if (sch_ep->esit == 1)
346 				sch_ep->pkts = esit_pkts;
347 			else if (esit_pkts <= sch_ep->esit)
348 				sch_ep->pkts = 1;
349 			else
350 				sch_ep->pkts = roundup_pow_of_two(esit_pkts)
351 					/ sch_ep->esit;
352 
353 			sch_ep->num_budget_microframes =
354 				DIV_ROUND_UP(esit_pkts, sch_ep->pkts);
355 
356 			sch_ep->repeat = !!(sch_ep->num_budget_microframes > 1);
357 			sch_ep->bw_cost_per_microframe = maxpkt * sch_ep->pkts;
358 
359 			for (i = 0; i < sch_ep->num_budget_microframes - 1; i++)
360 				bwb_table[i] = sch_ep->bw_cost_per_microframe;
361 
362 			/* last one <= bw_cost_per_microframe */
363 			bwb_table[i] = maxpkt * esit_pkts
364 				       - i * sch_ep->bw_cost_per_microframe;
365 		}
366 	} else if (is_fs_or_ls(sch_ep->speed)) {
367 		sch_ep->pkts = 1; /* at most one packet for each microframe */
368 
369 		/*
370 		 * num_budget_microframes and cs_count will be updated when
371 		 * check TT for INT_OUT_EP, ISOC/INT_IN_EP type
372 		 */
373 		sch_ep->cs_count = DIV_ROUND_UP(maxpkt, FS_PAYLOAD_MAX);
374 		sch_ep->num_budget_microframes = sch_ep->cs_count;
375 		sch_ep->bw_cost_per_microframe =
376 			(maxpkt < FS_PAYLOAD_MAX) ? maxpkt : FS_PAYLOAD_MAX;
377 
378 		/* init budget table */
379 		if (ep_type == ISOC_OUT_EP) {
380 			for (i = 0; i < sch_ep->num_budget_microframes; i++)
381 				bwb_table[i] =	sch_ep->bw_cost_per_microframe;
382 		} else if (ep_type == INT_OUT_EP) {
383 			/* only first one consumes bandwidth, others as zero */
384 			bwb_table[0] = sch_ep->bw_cost_per_microframe;
385 		} else { /* INT_IN_EP or ISOC_IN_EP */
386 			bwb_table[0] = 0; /* start split */
387 			bwb_table[1] = 0; /* idle */
388 			/*
389 			 * due to cs_count will be updated according to cs
390 			 * position, assign all remainder budget array
391 			 * elements as @bw_cost_per_microframe, but only first
392 			 * @num_budget_microframes elements will be used later
393 			 */
394 			for (i = 2; i < TT_MICROFRAMES_MAX; i++)
395 				bwb_table[i] =	sch_ep->bw_cost_per_microframe;
396 		}
397 	}
398 }
399 
400 /* Get maximum bandwidth when we schedule at offset slot. */
401 static u32 get_max_bw(struct mu3h_sch_bw_info *sch_bw,
402 	struct mu3h_sch_ep_info *sch_ep, u32 offset)
403 {
404 	u32 num_esit;
405 	u32 max_bw = 0;
406 	u32 bw;
407 	int i;
408 	int j;
409 
410 	num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
411 	for (i = 0; i < num_esit; i++) {
412 		u32 base = offset + i * sch_ep->esit;
413 
414 		for (j = 0; j < sch_ep->num_budget_microframes; j++) {
415 			bw = sch_bw->bus_bw[base + j] +
416 					sch_ep->bw_budget_table[j];
417 			if (bw > max_bw)
418 				max_bw = bw;
419 		}
420 	}
421 	return max_bw;
422 }
423 
424 static void update_bus_bw(struct mu3h_sch_bw_info *sch_bw,
425 	struct mu3h_sch_ep_info *sch_ep, bool used)
426 {
427 	u32 num_esit;
428 	u32 base;
429 	int i;
430 	int j;
431 
432 	num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
433 	for (i = 0; i < num_esit; i++) {
434 		base = sch_ep->offset + i * sch_ep->esit;
435 		for (j = 0; j < sch_ep->num_budget_microframes; j++) {
436 			if (used)
437 				sch_bw->bus_bw[base + j] +=
438 					sch_ep->bw_budget_table[j];
439 			else
440 				sch_bw->bus_bw[base + j] -=
441 					sch_ep->bw_budget_table[j];
442 		}
443 	}
444 }
445 
446 static int check_fs_bus_bw(struct mu3h_sch_ep_info *sch_ep, int offset)
447 {
448 	struct mu3h_sch_tt *tt = sch_ep->sch_tt;
449 	u32 num_esit, tmp;
450 	int base;
451 	int i, j;
452 
453 	num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
454 	for (i = 0; i < num_esit; i++) {
455 		base = offset + i * sch_ep->esit;
456 
457 		/*
458 		 * Compared with hs bus, no matter what ep type,
459 		 * the hub will always delay one uframe to send data
460 		 */
461 		for (j = 0; j < sch_ep->cs_count; j++) {
462 			tmp = tt->fs_bus_bw[base + j] + sch_ep->bw_cost_per_microframe;
463 			if (tmp > FS_PAYLOAD_MAX)
464 				return -ESCH_BW_OVERFLOW;
465 		}
466 	}
467 
468 	return 0;
469 }
470 
471 static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
472 {
473 	u32 extra_cs_count;
474 	u32 start_ss, last_ss;
475 	u32 start_cs, last_cs;
476 
477 	if (!sch_ep->sch_tt)
478 		return 0;
479 
480 	start_ss = offset % 8;
481 
482 	if (sch_ep->ep_type == ISOC_OUT_EP) {
483 		last_ss = start_ss + sch_ep->cs_count - 1;
484 
485 		/*
486 		 * usb_20 spec section11.18:
487 		 * must never schedule Start-Split in Y6
488 		 */
489 		if (!(start_ss == 7 || last_ss < 6))
490 			return -ESCH_SS_Y6;
491 
492 	} else {
493 		u32 cs_count = DIV_ROUND_UP(sch_ep->maxpkt, FS_PAYLOAD_MAX);
494 
495 		/*
496 		 * usb_20 spec section11.18:
497 		 * must never schedule Start-Split in Y6
498 		 */
499 		if (start_ss == 6)
500 			return -ESCH_SS_Y6;
501 
502 		/* one uframe for ss + one uframe for idle */
503 		start_cs = (start_ss + 2) % 8;
504 		last_cs = start_cs + cs_count - 1;
505 
506 		if (last_cs > 7)
507 			return -ESCH_CS_OVERFLOW;
508 
509 		if (sch_ep->ep_type == ISOC_IN_EP)
510 			extra_cs_count = (last_cs == 7) ? 1 : 2;
511 		else /*  ep_type : INTR IN / INTR OUT */
512 			extra_cs_count = 1;
513 
514 		cs_count += extra_cs_count;
515 		if (cs_count > 7)
516 			cs_count = 7; /* HW limit */
517 
518 		sch_ep->cs_count = cs_count;
519 		/* one for ss, the other for idle */
520 		sch_ep->num_budget_microframes = cs_count + 2;
521 
522 		/*
523 		 * if interval=1, maxp >752, num_budge_micoframe is larger
524 		 * than sch_ep->esit, will overstep boundary
525 		 */
526 		if (sch_ep->num_budget_microframes > sch_ep->esit)
527 			sch_ep->num_budget_microframes = sch_ep->esit;
528 	}
529 
530 	return check_fs_bus_bw(sch_ep, offset);
531 }
532 
533 static void update_sch_tt(struct mu3h_sch_ep_info *sch_ep, bool used)
534 {
535 	struct mu3h_sch_tt *tt = sch_ep->sch_tt;
536 	u32 base, num_esit;
537 	int bw_updated;
538 	int i, j;
539 
540 	num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
541 
542 	if (used)
543 		bw_updated = sch_ep->bw_cost_per_microframe;
544 	else
545 		bw_updated = -sch_ep->bw_cost_per_microframe;
546 
547 	for (i = 0; i < num_esit; i++) {
548 		base = sch_ep->offset + i * sch_ep->esit;
549 
550 		for (j = 0; j < sch_ep->cs_count; j++)
551 			tt->fs_bus_bw[base + j] += bw_updated;
552 	}
553 
554 	if (used)
555 		list_add_tail(&sch_ep->tt_endpoint, &tt->ep_list);
556 	else
557 		list_del(&sch_ep->tt_endpoint);
558 }
559 
560 static int load_ep_bw(struct mu3h_sch_bw_info *sch_bw,
561 		      struct mu3h_sch_ep_info *sch_ep, bool loaded)
562 {
563 	if (sch_ep->sch_tt)
564 		update_sch_tt(sch_ep, loaded);
565 
566 	/* update bus bandwidth info */
567 	update_bus_bw(sch_bw, sch_ep, loaded);
568 	sch_ep->allocated = loaded;
569 
570 	return 0;
571 }
572 
573 static u32 get_esit_boundary(struct mu3h_sch_ep_info *sch_ep)
574 {
575 	u32 boundary = sch_ep->esit;
576 
577 	if (sch_ep->sch_tt) { /* LS/FS with TT */
578 		/* tune for CS */
579 		if (sch_ep->ep_type != ISOC_OUT_EP)
580 			boundary++;
581 		else if (boundary > 1) /* normally esit >= 8 for FS/LS */
582 			boundary--;
583 	}
584 
585 	return boundary;
586 }
587 
588 static int check_sch_bw(struct mu3h_sch_bw_info *sch_bw,
589 			struct mu3h_sch_ep_info *sch_ep)
590 {
591 	const u32 esit_boundary = get_esit_boundary(sch_ep);
592 	const u32 bw_boundary = get_bw_boundary(sch_ep->speed);
593 	u32 offset;
594 	u32 worst_bw;
595 	u32 min_bw = ~0;
596 	int min_index = -1;
597 	int ret = 0;
598 
599 	/*
600 	 * Search through all possible schedule microframes.
601 	 * and find a microframe where its worst bandwidth is minimum.
602 	 */
603 	for (offset = 0; offset < sch_ep->esit; offset++) {
604 		ret = check_sch_tt(sch_ep, offset);
605 		if (ret)
606 			continue;
607 
608 		if ((offset + sch_ep->num_budget_microframes) > esit_boundary)
609 			break;
610 
611 		worst_bw = get_max_bw(sch_bw, sch_ep, offset);
612 		if (worst_bw > bw_boundary)
613 			continue;
614 
615 		if (min_bw > worst_bw) {
616 			min_bw = worst_bw;
617 			min_index = offset;
618 		}
619 
620 		/* use first-fit for LS/FS */
621 		if (sch_ep->sch_tt && min_index >= 0)
622 			break;
623 
624 		if (min_bw == 0)
625 			break;
626 	}
627 
628 	if (min_index < 0)
629 		return ret ? ret : -ESCH_BW_OVERFLOW;
630 
631 	sch_ep->offset = min_index;
632 
633 	return load_ep_bw(sch_bw, sch_ep, true);
634 }
635 
636 static void destroy_sch_ep(struct usb_device *udev,
637 	struct mu3h_sch_bw_info *sch_bw, struct mu3h_sch_ep_info *sch_ep)
638 {
639 	/* only release ep bw check passed by check_sch_bw() */
640 	if (sch_ep->allocated)
641 		load_ep_bw(sch_bw, sch_ep, false);
642 
643 	if (sch_ep->sch_tt)
644 		drop_tt(udev);
645 
646 	list_del(&sch_ep->endpoint);
647 	kfree(sch_ep);
648 }
649 
650 static bool need_bw_sch(struct usb_host_endpoint *ep,
651 	enum usb_device_speed speed, int has_tt)
652 {
653 	/* only for periodic endpoints */
654 	if (usb_endpoint_xfer_control(&ep->desc)
655 		|| usb_endpoint_xfer_bulk(&ep->desc))
656 		return false;
657 
658 	/*
659 	 * for LS & FS periodic endpoints which its device is not behind
660 	 * a TT are also ignored, root-hub will schedule them directly,
661 	 * but need set @bpkts field of endpoint context to 1.
662 	 */
663 	if (is_fs_or_ls(speed) && !has_tt)
664 		return false;
665 
666 	/* skip endpoint with zero maxpkt */
667 	if (usb_endpoint_maxp(&ep->desc) == 0)
668 		return false;
669 
670 	return true;
671 }
672 
673 int xhci_mtk_sch_init(struct xhci_hcd_mtk *mtk)
674 {
675 	struct xhci_hcd *xhci = hcd_to_xhci(mtk->hcd);
676 	struct mu3h_sch_bw_info *sch_array;
677 	int num_usb_bus;
678 	int i;
679 
680 	/* ss IN and OUT are separated */
681 	num_usb_bus = xhci->usb3_rhub.num_ports * 2 + xhci->usb2_rhub.num_ports;
682 
683 	sch_array = kcalloc(num_usb_bus, sizeof(*sch_array), GFP_KERNEL);
684 	if (sch_array == NULL)
685 		return -ENOMEM;
686 
687 	for (i = 0; i < num_usb_bus; i++)
688 		INIT_LIST_HEAD(&sch_array[i].bw_ep_list);
689 
690 	mtk->sch_array = sch_array;
691 
692 	INIT_LIST_HEAD(&mtk->bw_ep_chk_list);
693 
694 	return 0;
695 }
696 
697 void xhci_mtk_sch_exit(struct xhci_hcd_mtk *mtk)
698 {
699 	kfree(mtk->sch_array);
700 }
701 
702 static int add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
703 			struct usb_host_endpoint *ep)
704 {
705 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
706 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
707 	struct xhci_ep_ctx *ep_ctx;
708 	struct xhci_virt_device *virt_dev;
709 	struct mu3h_sch_ep_info *sch_ep;
710 	unsigned int ep_index;
711 
712 	virt_dev = xhci->devs[udev->slot_id];
713 	ep_index = xhci_get_endpoint_index(&ep->desc);
714 	ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
715 
716 	xhci_dbg(xhci, "%s %s\n", __func__, decode_ep(ep, udev->speed));
717 
718 	if (!need_bw_sch(ep, udev->speed, !!virt_dev->tt_info)) {
719 		/*
720 		 * set @bpkts to 1 if it is LS or FS periodic endpoint, and its
721 		 * device does not connected through an external HS hub
722 		 */
723 		if (usb_endpoint_xfer_int(&ep->desc)
724 			|| usb_endpoint_xfer_isoc(&ep->desc))
725 			ep_ctx->reserved[0] = cpu_to_le32(EP_BPKTS(1));
726 
727 		return 0;
728 	}
729 
730 	sch_ep = create_sch_ep(udev, ep, ep_ctx);
731 	if (IS_ERR_OR_NULL(sch_ep))
732 		return -ENOMEM;
733 
734 	setup_sch_info(ep_ctx, sch_ep);
735 
736 	list_add_tail(&sch_ep->endpoint, &mtk->bw_ep_chk_list);
737 
738 	return 0;
739 }
740 
741 static void drop_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
742 			  struct usb_host_endpoint *ep)
743 {
744 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
745 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
746 	struct xhci_virt_device *virt_dev;
747 	struct mu3h_sch_bw_info *sch_bw;
748 	struct mu3h_sch_ep_info *sch_ep, *tmp;
749 
750 	virt_dev = xhci->devs[udev->slot_id];
751 
752 	xhci_dbg(xhci, "%s %s\n", __func__, decode_ep(ep, udev->speed));
753 
754 	if (!need_bw_sch(ep, udev->speed, !!virt_dev->tt_info))
755 		return;
756 
757 	sch_bw = get_bw_info(mtk, udev, ep);
758 
759 	list_for_each_entry_safe(sch_ep, tmp, &sch_bw->bw_ep_list, endpoint) {
760 		if (sch_ep->ep == ep) {
761 			destroy_sch_ep(udev, sch_bw, sch_ep);
762 			break;
763 		}
764 	}
765 }
766 
767 int xhci_mtk_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
768 {
769 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
770 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
771 	struct xhci_virt_device *virt_dev = xhci->devs[udev->slot_id];
772 	struct mu3h_sch_bw_info *sch_bw;
773 	struct mu3h_sch_ep_info *sch_ep, *tmp;
774 	int ret;
775 
776 	xhci_dbg(xhci, "%s() udev %s\n", __func__, dev_name(&udev->dev));
777 
778 	list_for_each_entry(sch_ep, &mtk->bw_ep_chk_list, endpoint) {
779 		sch_bw = get_bw_info(mtk, udev, sch_ep->ep);
780 
781 		ret = check_sch_bw(sch_bw, sch_ep);
782 		if (ret) {
783 			xhci_err(xhci, "Not enough bandwidth! (%s)\n",
784 				 sch_error_string(-ret));
785 			return -ENOSPC;
786 		}
787 	}
788 
789 	list_for_each_entry_safe(sch_ep, tmp, &mtk->bw_ep_chk_list, endpoint) {
790 		struct xhci_ep_ctx *ep_ctx;
791 		struct usb_host_endpoint *ep = sch_ep->ep;
792 		unsigned int ep_index = xhci_get_endpoint_index(&ep->desc);
793 
794 		sch_bw = get_bw_info(mtk, udev, ep);
795 		list_move_tail(&sch_ep->endpoint, &sch_bw->bw_ep_list);
796 
797 		ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
798 		ep_ctx->reserved[0] = cpu_to_le32(EP_BPKTS(sch_ep->pkts)
799 			| EP_BCSCOUNT(sch_ep->cs_count)
800 			| EP_BBM(sch_ep->burst_mode));
801 		ep_ctx->reserved[1] = cpu_to_le32(EP_BOFFSET(sch_ep->offset)
802 			| EP_BREPEAT(sch_ep->repeat));
803 
804 		xhci_dbg(xhci, " PKTS:%x, CSCOUNT:%x, BM:%x, OFFSET:%x, REPEAT:%x\n",
805 			sch_ep->pkts, sch_ep->cs_count, sch_ep->burst_mode,
806 			sch_ep->offset, sch_ep->repeat);
807 	}
808 
809 	return xhci_check_bandwidth(hcd, udev);
810 }
811 
812 void xhci_mtk_reset_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
813 {
814 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
815 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
816 	struct mu3h_sch_bw_info *sch_bw;
817 	struct mu3h_sch_ep_info *sch_ep, *tmp;
818 
819 	xhci_dbg(xhci, "%s() udev %s\n", __func__, dev_name(&udev->dev));
820 
821 	list_for_each_entry_safe(sch_ep, tmp, &mtk->bw_ep_chk_list, endpoint) {
822 		sch_bw = get_bw_info(mtk, udev, sch_ep->ep);
823 		destroy_sch_ep(udev, sch_bw, sch_ep);
824 	}
825 
826 	xhci_reset_bandwidth(hcd, udev);
827 }
828 
829 int xhci_mtk_add_ep(struct usb_hcd *hcd, struct usb_device *udev,
830 		    struct usb_host_endpoint *ep)
831 {
832 	int ret;
833 
834 	ret = xhci_add_endpoint(hcd, udev, ep);
835 	if (ret)
836 		return ret;
837 
838 	if (ep->hcpriv)
839 		ret = add_ep_quirk(hcd, udev, ep);
840 
841 	return ret;
842 }
843 
844 int xhci_mtk_drop_ep(struct usb_hcd *hcd, struct usb_device *udev,
845 		     struct usb_host_endpoint *ep)
846 {
847 	int ret;
848 
849 	ret = xhci_drop_endpoint(hcd, udev, ep);
850 	if (ret)
851 		return ret;
852 
853 	if (ep->hcpriv)
854 		drop_ep_quirk(hcd, udev, ep);
855 
856 	return 0;
857 }
858