xref: /linux/drivers/usb/host/xhci-mtk-sch.c (revision eb01fe7abbe2d0b38824d2a93fdb4cc3eaf2ccc1)
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 #define LS_PAYLOAD_MAX 18
23 /* section 11.18.1, per fs frame */
24 #define FS_BW_BOUNDARY	1157
25 #define LS_BW_BOUNDARY	144
26 
27 /*
28  * max number of microframes for split transfer, assume extra-cs budget is 0
29  * for fs isoc in : 1 ss + 1 idle + 6 cs (roundup(1023/188))
30  */
31 #define TT_MICROFRAMES_MAX	8
32 /* offset from SS for fs/ls isoc/intr ep (ss + idle) */
33 #define CS_OFFSET	2
34 
35 #define DBG_BUF_EN	64
36 
37 /* schedule error type */
38 #define ESCH_SS_Y6		1001
39 #define ESCH_SS_OVERLAP		1002
40 #define ESCH_CS_OVERFLOW	1003
41 #define ESCH_BW_OVERFLOW	1004
42 #define ESCH_FIXME		1005
43 
44 /* mtk scheduler bitmasks */
45 #define EP_BPKTS(p)	((p) & 0x7f)
46 #define EP_BCSCOUNT(p)	(((p) & 0x7) << 8)
47 #define EP_BBM(p)	((p) << 11)
48 #define EP_BOFFSET(p)	((p) & 0x3fff)
49 #define EP_BREPEAT(p)	(((p) & 0x7fff) << 16)
50 
51 static char *sch_error_string(int err_num)
52 {
53 	switch (err_num) {
54 	case ESCH_SS_Y6:
55 		return "Can't schedule Start-Split in Y6";
56 	case ESCH_SS_OVERLAP:
57 		return "Can't find a suitable Start-Split location";
58 	case ESCH_CS_OVERFLOW:
59 		return "The last Complete-Split is greater than 7";
60 	case ESCH_BW_OVERFLOW:
61 		return "Bandwidth exceeds the maximum limit";
62 	case ESCH_FIXME:
63 		return "FIXME, to be resolved";
64 	default:
65 		return "Unknown";
66 	}
67 }
68 
69 static int is_fs_or_ls(enum usb_device_speed speed)
70 {
71 	return speed == USB_SPEED_FULL || speed == USB_SPEED_LOW;
72 }
73 
74 static const char *
75 decode_ep(struct usb_host_endpoint *ep, enum usb_device_speed speed)
76 {
77 	static char buf[DBG_BUF_EN];
78 	struct usb_endpoint_descriptor *epd = &ep->desc;
79 	unsigned int interval;
80 	const char *unit;
81 
82 	interval = usb_decode_interval(epd, speed);
83 	if (interval % 1000) {
84 		unit = "us";
85 	} else {
86 		unit = "ms";
87 		interval /= 1000;
88 	}
89 
90 	snprintf(buf, DBG_BUF_EN, "%s ep%d%s %s, mpkt:%d, interval:%d/%d%s",
91 		 usb_speed_string(speed), usb_endpoint_num(epd),
92 		 usb_endpoint_dir_in(epd) ? "in" : "out",
93 		 usb_ep_type_string(usb_endpoint_type(epd)),
94 		 usb_endpoint_maxp(epd), epd->bInterval, interval, unit);
95 
96 	return buf;
97 }
98 
99 static u32 get_bw_boundary(enum usb_device_speed speed)
100 {
101 	u32 boundary;
102 
103 	switch (speed) {
104 	case USB_SPEED_SUPER_PLUS:
105 		boundary = SSP_BW_BOUNDARY;
106 		break;
107 	case USB_SPEED_SUPER:
108 		boundary = SS_BW_BOUNDARY;
109 		break;
110 	default:
111 		boundary = HS_BW_BOUNDARY;
112 		break;
113 	}
114 
115 	return boundary;
116 }
117 
118 /*
119 * get the bandwidth domain which @ep belongs to.
120 *
121 * the bandwidth domain array is saved to @sch_array of struct xhci_hcd_mtk,
122 * each HS root port is treated as a single bandwidth domain,
123 * but each SS root port is treated as two bandwidth domains, one for IN eps,
124 * one for OUT eps.
125 * @real_port value is defined as follow according to xHCI spec:
126 * 1 for SSport0, ..., N+1 for SSportN, N+2 for HSport0, N+3 for HSport1, etc
127 * so the bandwidth domain array is organized as follow for simplification:
128 * SSport0-OUT, SSport0-IN, ..., SSportX-OUT, SSportX-IN, HSport0, ..., HSportY
129 */
130 static struct mu3h_sch_bw_info *
131 get_bw_info(struct xhci_hcd_mtk *mtk, struct usb_device *udev,
132 	    struct usb_host_endpoint *ep)
133 {
134 	struct xhci_hcd *xhci = hcd_to_xhci(mtk->hcd);
135 	struct xhci_virt_device *virt_dev;
136 	int bw_index;
137 
138 	virt_dev = xhci->devs[udev->slot_id];
139 	if (!virt_dev->real_port) {
140 		WARN_ONCE(1, "%s invalid real_port\n", dev_name(&udev->dev));
141 		return NULL;
142 	}
143 
144 	if (udev->speed >= USB_SPEED_SUPER) {
145 		if (usb_endpoint_dir_out(&ep->desc))
146 			bw_index = (virt_dev->real_port - 1) * 2;
147 		else
148 			bw_index = (virt_dev->real_port - 1) * 2 + 1;
149 	} else {
150 		/* add one more for each SS port */
151 		bw_index = virt_dev->real_port + xhci->usb3_rhub.num_ports - 1;
152 	}
153 
154 	return &mtk->sch_array[bw_index];
155 }
156 
157 static u32 get_esit(struct xhci_ep_ctx *ep_ctx)
158 {
159 	u32 esit;
160 
161 	esit = 1 << CTX_TO_EP_INTERVAL(le32_to_cpu(ep_ctx->ep_info));
162 	if (esit > XHCI_MTK_MAX_ESIT)
163 		esit = XHCI_MTK_MAX_ESIT;
164 
165 	return esit;
166 }
167 
168 static struct mu3h_sch_tt *find_tt(struct usb_device *udev)
169 {
170 	struct usb_tt *utt = udev->tt;
171 	struct mu3h_sch_tt *tt, **tt_index, **ptt;
172 	bool allocated_index = false;
173 
174 	if (!utt)
175 		return NULL;	/* Not below a TT */
176 
177 	/*
178 	 * Find/create our data structure.
179 	 * For hubs with a single TT, we get it directly.
180 	 * For hubs with multiple TTs, there's an extra level of pointers.
181 	 */
182 	tt_index = NULL;
183 	if (utt->multi) {
184 		tt_index = utt->hcpriv;
185 		if (!tt_index) {	/* Create the index array */
186 			tt_index = kcalloc(utt->hub->maxchild,
187 					sizeof(*tt_index), GFP_KERNEL);
188 			if (!tt_index)
189 				return ERR_PTR(-ENOMEM);
190 			utt->hcpriv = tt_index;
191 			allocated_index = true;
192 		}
193 		ptt = &tt_index[udev->ttport - 1];
194 	} else {
195 		ptt = (struct mu3h_sch_tt **) &utt->hcpriv;
196 	}
197 
198 	tt = *ptt;
199 	if (!tt) {	/* Create the mu3h_sch_tt */
200 		tt = kzalloc(sizeof(*tt), GFP_KERNEL);
201 		if (!tt) {
202 			if (allocated_index) {
203 				utt->hcpriv = NULL;
204 				kfree(tt_index);
205 			}
206 			return ERR_PTR(-ENOMEM);
207 		}
208 		INIT_LIST_HEAD(&tt->ep_list);
209 		*ptt = tt;
210 	}
211 
212 	return tt;
213 }
214 
215 /* Release the TT above udev, if it's not in use */
216 static void drop_tt(struct usb_device *udev)
217 {
218 	struct usb_tt *utt = udev->tt;
219 	struct mu3h_sch_tt *tt, **tt_index, **ptt;
220 	int i, cnt;
221 
222 	if (!utt || !utt->hcpriv)
223 		return;		/* Not below a TT, or never allocated */
224 
225 	cnt = 0;
226 	if (utt->multi) {
227 		tt_index = utt->hcpriv;
228 		ptt = &tt_index[udev->ttport - 1];
229 		/*  How many entries are left in tt_index? */
230 		for (i = 0; i < utt->hub->maxchild; ++i)
231 			cnt += !!tt_index[i];
232 	} else {
233 		tt_index = NULL;
234 		ptt = (struct mu3h_sch_tt **)&utt->hcpriv;
235 	}
236 
237 	tt = *ptt;
238 	if (!tt || !list_empty(&tt->ep_list))
239 		return;		/* never allocated , or still in use*/
240 
241 	*ptt = NULL;
242 	kfree(tt);
243 
244 	if (cnt == 1) {
245 		utt->hcpriv = NULL;
246 		kfree(tt_index);
247 	}
248 }
249 
250 static struct mu3h_sch_ep_info *
251 create_sch_ep(struct xhci_hcd_mtk *mtk, struct usb_device *udev,
252 	      struct usb_host_endpoint *ep, struct xhci_ep_ctx *ep_ctx)
253 {
254 	struct mu3h_sch_ep_info *sch_ep;
255 	struct mu3h_sch_bw_info *bw_info;
256 	struct mu3h_sch_tt *tt = NULL;
257 	u32 len;
258 
259 	bw_info = get_bw_info(mtk, udev, ep);
260 	if (!bw_info)
261 		return ERR_PTR(-ENODEV);
262 
263 	if (is_fs_or_ls(udev->speed))
264 		len = TT_MICROFRAMES_MAX;
265 	else if ((udev->speed >= USB_SPEED_SUPER) &&
266 		 usb_endpoint_xfer_isoc(&ep->desc))
267 		len = get_esit(ep_ctx);
268 	else
269 		len = 1;
270 
271 	sch_ep = kzalloc(struct_size(sch_ep, bw_budget_table, len), GFP_KERNEL);
272 	if (!sch_ep)
273 		return ERR_PTR(-ENOMEM);
274 
275 	if (is_fs_or_ls(udev->speed)) {
276 		tt = find_tt(udev);
277 		if (IS_ERR(tt)) {
278 			kfree(sch_ep);
279 			return ERR_PTR(-ENOMEM);
280 		}
281 	}
282 
283 	sch_ep->bw_info = bw_info;
284 	sch_ep->sch_tt = tt;
285 	sch_ep->ep = ep;
286 	sch_ep->speed = udev->speed;
287 	INIT_LIST_HEAD(&sch_ep->endpoint);
288 	INIT_LIST_HEAD(&sch_ep->tt_endpoint);
289 	INIT_HLIST_NODE(&sch_ep->hentry);
290 
291 	return sch_ep;
292 }
293 
294 static void setup_sch_info(struct xhci_ep_ctx *ep_ctx,
295 			   struct mu3h_sch_ep_info *sch_ep)
296 {
297 	u32 ep_type;
298 	u32 maxpkt;
299 	u32 max_burst;
300 	u32 mult;
301 	u32 esit_pkts;
302 	u32 max_esit_payload;
303 	u32 bw_per_microframe;
304 	u32 *bwb_table;
305 	int i;
306 
307 	bwb_table = sch_ep->bw_budget_table;
308 	ep_type = CTX_TO_EP_TYPE(le32_to_cpu(ep_ctx->ep_info2));
309 	maxpkt = MAX_PACKET_DECODED(le32_to_cpu(ep_ctx->ep_info2));
310 	max_burst = CTX_TO_MAX_BURST(le32_to_cpu(ep_ctx->ep_info2));
311 	mult = CTX_TO_EP_MULT(le32_to_cpu(ep_ctx->ep_info));
312 	max_esit_payload =
313 		(CTX_TO_MAX_ESIT_PAYLOAD_HI(
314 			le32_to_cpu(ep_ctx->ep_info)) << 16) |
315 		 CTX_TO_MAX_ESIT_PAYLOAD(le32_to_cpu(ep_ctx->tx_info));
316 
317 	sch_ep->esit = get_esit(ep_ctx);
318 	sch_ep->num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
319 	sch_ep->ep_type = ep_type;
320 	sch_ep->maxpkt = maxpkt;
321 	sch_ep->offset = 0;
322 	sch_ep->burst_mode = 0;
323 	sch_ep->repeat = 0;
324 
325 	if (sch_ep->speed == USB_SPEED_HIGH) {
326 		sch_ep->cs_count = 0;
327 
328 		/*
329 		 * usb_20 spec section5.9
330 		 * a single microframe is enough for HS synchromous endpoints
331 		 * in a interval
332 		 */
333 		sch_ep->num_budget_microframes = 1;
334 
335 		/*
336 		 * xHCI spec section6.2.3.4
337 		 * @max_burst is the number of additional transactions
338 		 * opportunities per microframe
339 		 */
340 		sch_ep->pkts = max_burst + 1;
341 		bwb_table[0] = maxpkt * sch_ep->pkts;
342 	} else if (sch_ep->speed >= USB_SPEED_SUPER) {
343 		/* usb3_r1 spec section4.4.7 & 4.4.8 */
344 		sch_ep->cs_count = 0;
345 		sch_ep->burst_mode = 1;
346 		/*
347 		 * some device's (d)wBytesPerInterval is set as 0,
348 		 * then max_esit_payload is 0, so evaluate esit_pkts from
349 		 * mult and burst
350 		 */
351 		esit_pkts = DIV_ROUND_UP(max_esit_payload, maxpkt);
352 		if (esit_pkts == 0)
353 			esit_pkts = (mult + 1) * (max_burst + 1);
354 
355 		if (ep_type == INT_IN_EP || ep_type == INT_OUT_EP) {
356 			sch_ep->pkts = esit_pkts;
357 			sch_ep->num_budget_microframes = 1;
358 			bwb_table[0] = maxpkt * sch_ep->pkts;
359 		}
360 
361 		if (ep_type == ISOC_IN_EP || ep_type == ISOC_OUT_EP) {
362 
363 			if (sch_ep->esit == 1)
364 				sch_ep->pkts = esit_pkts;
365 			else if (esit_pkts <= sch_ep->esit)
366 				sch_ep->pkts = 1;
367 			else
368 				sch_ep->pkts = roundup_pow_of_two(esit_pkts)
369 					/ sch_ep->esit;
370 
371 			sch_ep->num_budget_microframes =
372 				DIV_ROUND_UP(esit_pkts, sch_ep->pkts);
373 
374 			sch_ep->repeat = !!(sch_ep->num_budget_microframes > 1);
375 			bw_per_microframe = maxpkt * sch_ep->pkts;
376 
377 			for (i = 0; i < sch_ep->num_budget_microframes - 1; i++)
378 				bwb_table[i] = bw_per_microframe;
379 
380 			/* last one <= bw_per_microframe */
381 			bwb_table[i] = maxpkt * esit_pkts - i * bw_per_microframe;
382 		}
383 	} else if (is_fs_or_ls(sch_ep->speed)) {
384 		sch_ep->pkts = 1; /* at most one packet for each microframe */
385 
386 		/*
387 		 * @cs_count will be updated to add extra-cs when
388 		 * check TT for INT_OUT_EP, ISOC/INT_IN_EP type
389 		 * @maxpkt <= 1023;
390 		 */
391 		sch_ep->cs_count = DIV_ROUND_UP(maxpkt, FS_PAYLOAD_MAX);
392 		sch_ep->num_budget_microframes = sch_ep->cs_count;
393 
394 		/* init budget table */
395 		if (ep_type == ISOC_OUT_EP) {
396 			for (i = 0; i < sch_ep->cs_count - 1; i++)
397 				bwb_table[i] = FS_PAYLOAD_MAX;
398 
399 			bwb_table[i] = maxpkt - i * FS_PAYLOAD_MAX;
400 		} else if (ep_type == INT_OUT_EP) {
401 			/* only first one used (maxpkt <= 64), others zero */
402 			bwb_table[0] = maxpkt;
403 		} else { /* INT_IN_EP or ISOC_IN_EP */
404 			bwb_table[0] = 0; /* start split */
405 			bwb_table[1] = 0; /* idle */
406 			/*
407 			 * @cs_count will be updated according to cs position
408 			 * (add 1 or 2 extra-cs), but assume only first
409 			 * @num_budget_microframes elements will be used later,
410 			 * although in fact it does not (extra-cs budget many receive
411 			 * some data for IN ep);
412 			 * @cs_count is 1 for INT_IN_EP (maxpkt <= 64);
413 			 */
414 			for (i = 0; i < sch_ep->cs_count - 1; i++)
415 				bwb_table[i + CS_OFFSET] = FS_PAYLOAD_MAX;
416 
417 			bwb_table[i + CS_OFFSET] = maxpkt - i * FS_PAYLOAD_MAX;
418 			/* ss + idle */
419 			sch_ep->num_budget_microframes += CS_OFFSET;
420 		}
421 	}
422 }
423 
424 /* Get maximum bandwidth when we schedule at offset slot. */
425 static u32 get_max_bw(struct mu3h_sch_bw_info *sch_bw,
426 	struct mu3h_sch_ep_info *sch_ep, u32 offset)
427 {
428 	u32 max_bw = 0;
429 	u32 bw;
430 	int i, j, k;
431 
432 	for (i = 0; i < sch_ep->num_esit; i++) {
433 		u32 base = offset + i * sch_ep->esit;
434 
435 		for (j = 0; j < sch_ep->num_budget_microframes; j++) {
436 			k = XHCI_MTK_BW_INDEX(base + j);
437 			bw = sch_bw->bus_bw[k] + sch_ep->bw_budget_table[j];
438 			if (bw > max_bw)
439 				max_bw = bw;
440 		}
441 	}
442 	return max_bw;
443 }
444 
445 /*
446  * for OUT: get first SS consumed bw;
447  * for IN: get first CS consumed bw;
448  */
449 static u16 get_fs_bw(struct mu3h_sch_ep_info *sch_ep, int offset)
450 {
451 	struct mu3h_sch_tt *tt = sch_ep->sch_tt;
452 	u16 fs_bw;
453 
454 	if (sch_ep->ep_type == ISOC_OUT_EP || sch_ep->ep_type == INT_OUT_EP)
455 		fs_bw = tt->fs_bus_bw_out[XHCI_MTK_BW_INDEX(offset)];
456 	else	/* skip ss + idle */
457 		fs_bw = tt->fs_bus_bw_in[XHCI_MTK_BW_INDEX(offset + CS_OFFSET)];
458 
459 	return fs_bw;
460 }
461 
462 static void update_bus_bw(struct mu3h_sch_bw_info *sch_bw,
463 	struct mu3h_sch_ep_info *sch_ep, bool used)
464 {
465 	u32 base;
466 	int i, j, k;
467 
468 	for (i = 0; i < sch_ep->num_esit; i++) {
469 		base = sch_ep->offset + i * sch_ep->esit;
470 		for (j = 0; j < sch_ep->num_budget_microframes; j++) {
471 			k = XHCI_MTK_BW_INDEX(base + j);
472 			if (used)
473 				sch_bw->bus_bw[k] += sch_ep->bw_budget_table[j];
474 			else
475 				sch_bw->bus_bw[k] -= sch_ep->bw_budget_table[j];
476 		}
477 	}
478 }
479 
480 static int check_ls_budget_microframes(struct mu3h_sch_ep_info *sch_ep, int offset)
481 {
482 	struct mu3h_sch_tt *tt = sch_ep->sch_tt;
483 	int i;
484 
485 	if (sch_ep->speed != USB_SPEED_LOW)
486 		return 0;
487 
488 	if (sch_ep->ep_type == INT_OUT_EP)
489 		i = XHCI_MTK_BW_INDEX(offset);
490 	else if (sch_ep->ep_type == INT_IN_EP)
491 		i = XHCI_MTK_BW_INDEX(offset + CS_OFFSET); /* skip ss + idle */
492 	else
493 		return -EINVAL;
494 
495 	if (tt->ls_bus_bw[i] + sch_ep->maxpkt > LS_PAYLOAD_MAX)
496 		return -ESCH_BW_OVERFLOW;
497 
498 	return 0;
499 }
500 
501 static int check_fs_budget_microframes(struct mu3h_sch_ep_info *sch_ep, int offset)
502 {
503 	struct mu3h_sch_tt *tt = sch_ep->sch_tt;
504 	u32 tmp;
505 	int i, k;
506 
507 	/*
508 	 * for OUT eps, will transfer exactly assigned length of data,
509 	 * so can't allocate more than 188 bytes;
510 	 * but it's not for IN eps, usually it can't receive full
511 	 * 188 bytes in a uframe, if it not assign full 188 bytes,
512 	 * can add another one;
513 	 */
514 	for (i = 0; i < sch_ep->num_budget_microframes; i++) {
515 		k = XHCI_MTK_BW_INDEX(offset + i);
516 		if (sch_ep->ep_type == ISOC_OUT_EP || sch_ep->ep_type == INT_OUT_EP)
517 			tmp = tt->fs_bus_bw_out[k] + sch_ep->bw_budget_table[i];
518 		else /* ep_type : ISOC IN / INTR IN */
519 			tmp = tt->fs_bus_bw_in[k];
520 
521 		if (tmp > FS_PAYLOAD_MAX)
522 			return -ESCH_BW_OVERFLOW;
523 	}
524 
525 	return 0;
526 }
527 
528 static int check_fs_budget_frames(struct mu3h_sch_ep_info *sch_ep, int offset)
529 {
530 	struct mu3h_sch_tt *tt = sch_ep->sch_tt;
531 	u32 head, tail;
532 	int i, j, k;
533 
534 	/* bugdet scheduled may cross at most two fs frames */
535 	j = XHCI_MTK_BW_INDEX(offset) / UFRAMES_PER_FRAME;
536 	k = XHCI_MTK_BW_INDEX(offset + sch_ep->num_budget_microframes - 1) / UFRAMES_PER_FRAME;
537 
538 	if (j != k) {
539 		head = tt->fs_frame_bw[j];
540 		tail = tt->fs_frame_bw[k];
541 	} else {
542 		head = tt->fs_frame_bw[j];
543 		tail = 0;
544 	}
545 
546 	j = roundup(offset, UFRAMES_PER_FRAME);
547 	for (i = 0; i < sch_ep->num_budget_microframes; i++) {
548 		if ((offset + i) < j)
549 			head += sch_ep->bw_budget_table[i];
550 		else
551 			tail += sch_ep->bw_budget_table[i];
552 	}
553 
554 	if (head > FS_BW_BOUNDARY || tail > FS_BW_BOUNDARY)
555 		return -ESCH_BW_OVERFLOW;
556 
557 	return 0;
558 }
559 
560 static int check_fs_bus_bw(struct mu3h_sch_ep_info *sch_ep, int offset)
561 {
562 	int i, base;
563 	int ret = 0;
564 
565 	for (i = 0; i < sch_ep->num_esit; i++) {
566 		base = offset + i * sch_ep->esit;
567 
568 		ret = check_ls_budget_microframes(sch_ep, base);
569 		if (ret)
570 			goto err;
571 
572 		ret = check_fs_budget_microframes(sch_ep, base);
573 		if (ret)
574 			goto err;
575 
576 		ret = check_fs_budget_frames(sch_ep, base);
577 		if (ret)
578 			goto err;
579 	}
580 
581 err:
582 	return ret;
583 }
584 
585 static int check_ss_and_cs(struct mu3h_sch_ep_info *sch_ep, u32 offset)
586 {
587 	u32 start_ss, last_ss;
588 	u32 start_cs, last_cs;
589 
590 	start_ss = offset % UFRAMES_PER_FRAME;
591 
592 	if (sch_ep->ep_type == ISOC_OUT_EP) {
593 		last_ss = start_ss + sch_ep->cs_count - 1;
594 
595 		/*
596 		 * usb_20 spec section11.18:
597 		 * must never schedule Start-Split in Y6
598 		 */
599 		if (!(start_ss == 7 || last_ss < 6))
600 			return -ESCH_SS_Y6;
601 
602 	} else {
603 		/* maxpkt <= 1023, cs <= 6 */
604 		u32 cs_count = DIV_ROUND_UP(sch_ep->maxpkt, FS_PAYLOAD_MAX);
605 
606 		/*
607 		 * usb_20 spec section11.18:
608 		 * must never schedule Start-Split in Y6
609 		 */
610 		if (start_ss == 6)
611 			return -ESCH_SS_Y6;
612 
613 		/* one uframe for ss + one uframe for idle */
614 		start_cs = (start_ss + CS_OFFSET) % UFRAMES_PER_FRAME;
615 		last_cs = start_cs + cs_count - 1;
616 		if (last_cs > 7)
617 			return -ESCH_CS_OVERFLOW;
618 
619 		/* add extra-cs */
620 		cs_count += (last_cs == 7) ? 1 : 2;
621 		if (cs_count > 7)
622 			cs_count = 7; /* HW limit */
623 
624 		sch_ep->cs_count = cs_count;
625 
626 	}
627 
628 	return 0;
629 }
630 
631 /*
632  * when isoc-out transfers 188 bytes in a uframe, and send isoc/intr's
633  * ss token in the uframe, may cause 'bit stuff error' in downstream
634  * port;
635  * when isoc-out transfer less than 188 bytes in a uframe, shall send
636  * isoc-in's ss after isoc-out's ss (but hw can't ensure the sequence,
637  * so just avoid overlap).
638  */
639 static int check_isoc_ss_overlap(struct mu3h_sch_ep_info *sch_ep, u32 offset)
640 {
641 	struct mu3h_sch_tt *tt = sch_ep->sch_tt;
642 	int base;
643 	int i, j, k;
644 
645 	if (!tt)
646 		return 0;
647 
648 	for (i = 0; i < sch_ep->num_esit; i++) {
649 		base = offset + i * sch_ep->esit;
650 
651 		if (sch_ep->ep_type == ISOC_OUT_EP) {
652 			for (j = 0; j < sch_ep->num_budget_microframes; j++) {
653 				k = XHCI_MTK_BW_INDEX(base + j);
654 				if (tt->in_ss_cnt[k])
655 					return -ESCH_SS_OVERLAP;
656 			}
657 		} else if (sch_ep->ep_type == ISOC_IN_EP || sch_ep->ep_type == INT_IN_EP) {
658 			k = XHCI_MTK_BW_INDEX(base);
659 			/* only check IN's ss */
660 			if (tt->fs_bus_bw_out[k])
661 				return -ESCH_SS_OVERLAP;
662 		}
663 	}
664 
665 	return 0;
666 }
667 
668 static int check_sch_tt_budget(struct mu3h_sch_ep_info *sch_ep, u32 offset)
669 {
670 	int ret;
671 
672 	ret = check_ss_and_cs(sch_ep, offset);
673 	if (ret)
674 		return ret;
675 
676 	ret = check_isoc_ss_overlap(sch_ep, offset);
677 	if (ret)
678 		return ret;
679 
680 	return check_fs_bus_bw(sch_ep, offset);
681 }
682 
683 /* allocate microframes in the ls/fs frame */
684 static int alloc_sch_portion_of_frame(struct mu3h_sch_ep_info *sch_ep)
685 {
686 	struct mu3h_sch_bw_info *sch_bw = sch_ep->bw_info;
687 	const u32 bw_boundary = get_bw_boundary(sch_ep->speed);
688 	u32 bw_max, fs_bw_min;
689 	u32 offset, offset_min;
690 	u16 fs_bw;
691 	int frames;
692 	int i, j;
693 	int ret;
694 
695 	frames = sch_ep->esit / UFRAMES_PER_FRAME;
696 
697 	for (i = 0; i < UFRAMES_PER_FRAME; i++) {
698 		fs_bw_min = FS_PAYLOAD_MAX;
699 		offset_min = XHCI_MTK_MAX_ESIT;
700 
701 		for (j = 0; j < frames; j++) {
702 			offset = (i + j * UFRAMES_PER_FRAME) % sch_ep->esit;
703 
704 			ret = check_sch_tt_budget(sch_ep, offset);
705 			if (ret)
706 				continue;
707 
708 			/* check hs bw domain */
709 			bw_max = get_max_bw(sch_bw, sch_ep, offset);
710 			if (bw_max > bw_boundary) {
711 				ret = -ESCH_BW_OVERFLOW;
712 				continue;
713 			}
714 
715 			/* use best-fit between frames */
716 			fs_bw = get_fs_bw(sch_ep, offset);
717 			if (fs_bw < fs_bw_min) {
718 				fs_bw_min = fs_bw;
719 				offset_min = offset;
720 			}
721 
722 			if (!fs_bw_min)
723 				break;
724 		}
725 
726 		/* use first-fit between microframes in a frame */
727 		if (offset_min < XHCI_MTK_MAX_ESIT)
728 			break;
729 	}
730 
731 	if (offset_min == XHCI_MTK_MAX_ESIT)
732 		return -ESCH_BW_OVERFLOW;
733 
734 	sch_ep->offset = offset_min;
735 
736 	return 0;
737 }
738 
739 static void update_sch_tt(struct mu3h_sch_ep_info *sch_ep, bool used)
740 {
741 	struct mu3h_sch_tt *tt = sch_ep->sch_tt;
742 	u16 *fs_bus_bw;
743 	u32 base;
744 	int i, j, k, f;
745 
746 	if (sch_ep->ep_type == ISOC_OUT_EP || sch_ep->ep_type == INT_OUT_EP)
747 		fs_bus_bw = tt->fs_bus_bw_out;
748 	else
749 		fs_bus_bw = tt->fs_bus_bw_in;
750 
751 	for (i = 0; i < sch_ep->num_esit; i++) {
752 		base = sch_ep->offset + i * sch_ep->esit;
753 
754 		for (j = 0; j < sch_ep->num_budget_microframes; j++) {
755 			k = XHCI_MTK_BW_INDEX(base + j);
756 			f = k / UFRAMES_PER_FRAME;
757 			if (used) {
758 				if (sch_ep->speed == USB_SPEED_LOW)
759 					tt->ls_bus_bw[k] += (u8)sch_ep->bw_budget_table[j];
760 
761 				fs_bus_bw[k] += (u16)sch_ep->bw_budget_table[j];
762 				tt->fs_frame_bw[f] += (u16)sch_ep->bw_budget_table[j];
763 			} else {
764 				if (sch_ep->speed == USB_SPEED_LOW)
765 					tt->ls_bus_bw[k] -= (u8)sch_ep->bw_budget_table[j];
766 
767 				fs_bus_bw[k] -= (u16)sch_ep->bw_budget_table[j];
768 				tt->fs_frame_bw[f] -= (u16)sch_ep->bw_budget_table[j];
769 			}
770 		}
771 
772 		if (sch_ep->ep_type == ISOC_IN_EP || sch_ep->ep_type == INT_IN_EP) {
773 			k = XHCI_MTK_BW_INDEX(base);
774 			if (used)
775 				tt->in_ss_cnt[k]++;
776 			else
777 				tt->in_ss_cnt[k]--;
778 		}
779 	}
780 
781 	if (used)
782 		list_add_tail(&sch_ep->tt_endpoint, &tt->ep_list);
783 	else
784 		list_del(&sch_ep->tt_endpoint);
785 }
786 
787 static int load_ep_bw(struct mu3h_sch_bw_info *sch_bw,
788 		      struct mu3h_sch_ep_info *sch_ep, bool loaded)
789 {
790 	if (sch_ep->sch_tt)
791 		update_sch_tt(sch_ep, loaded);
792 
793 	/* update bus bandwidth info */
794 	update_bus_bw(sch_bw, sch_ep, loaded);
795 	sch_ep->allocated = loaded;
796 
797 	return 0;
798 }
799 
800 /* allocate microframes for hs/ss/ssp */
801 static int alloc_sch_microframes(struct mu3h_sch_ep_info *sch_ep)
802 {
803 	struct mu3h_sch_bw_info *sch_bw = sch_ep->bw_info;
804 	const u32 bw_boundary = get_bw_boundary(sch_ep->speed);
805 	u32 offset;
806 	u32 worst_bw;
807 	u32 min_bw = ~0;
808 	int min_index = -1;
809 
810 	/*
811 	 * Search through all possible schedule microframes.
812 	 * and find a microframe where its worst bandwidth is minimum.
813 	 */
814 	for (offset = 0; offset < sch_ep->esit; offset++) {
815 
816 		worst_bw = get_max_bw(sch_bw, sch_ep, offset);
817 		if (worst_bw > bw_boundary)
818 			continue;
819 
820 		if (min_bw > worst_bw) {
821 			min_bw = worst_bw;
822 			min_index = offset;
823 		}
824 	}
825 
826 	if (min_index < 0)
827 		return -ESCH_BW_OVERFLOW;
828 
829 	sch_ep->offset = min_index;
830 
831 	return 0;
832 }
833 
834 static int check_sch_bw(struct mu3h_sch_ep_info *sch_ep)
835 {
836 	int ret;
837 
838 	if (sch_ep->sch_tt)
839 		ret = alloc_sch_portion_of_frame(sch_ep);
840 	else
841 		ret = alloc_sch_microframes(sch_ep);
842 
843 	if (ret)
844 		return ret;
845 
846 	return load_ep_bw(sch_ep->bw_info, sch_ep, true);
847 }
848 
849 static void destroy_sch_ep(struct xhci_hcd_mtk *mtk, struct usb_device *udev,
850 			   struct mu3h_sch_ep_info *sch_ep)
851 {
852 	/* only release ep bw check passed by check_sch_bw() */
853 	if (sch_ep->allocated)
854 		load_ep_bw(sch_ep->bw_info, sch_ep, false);
855 
856 	if (sch_ep->sch_tt)
857 		drop_tt(udev);
858 
859 	list_del(&sch_ep->endpoint);
860 	hlist_del(&sch_ep->hentry);
861 	kfree(sch_ep);
862 }
863 
864 static bool need_bw_sch(struct usb_device *udev,
865 			struct usb_host_endpoint *ep)
866 {
867 	bool has_tt = udev->tt && udev->tt->hub->parent;
868 
869 	/* only for periodic endpoints */
870 	if (usb_endpoint_xfer_control(&ep->desc)
871 		|| usb_endpoint_xfer_bulk(&ep->desc))
872 		return false;
873 
874 	/*
875 	 * for LS & FS periodic endpoints which its device is not behind
876 	 * a TT are also ignored, root-hub will schedule them directly,
877 	 * but need set @bpkts field of endpoint context to 1.
878 	 */
879 	if (is_fs_or_ls(udev->speed) && !has_tt)
880 		return false;
881 
882 	/* skip endpoint with zero maxpkt */
883 	if (usb_endpoint_maxp(&ep->desc) == 0)
884 		return false;
885 
886 	return true;
887 }
888 
889 int xhci_mtk_sch_init(struct xhci_hcd_mtk *mtk)
890 {
891 	struct xhci_hcd *xhci = hcd_to_xhci(mtk->hcd);
892 	struct mu3h_sch_bw_info *sch_array;
893 	int num_usb_bus;
894 
895 	/* ss IN and OUT are separated */
896 	num_usb_bus = xhci->usb3_rhub.num_ports * 2 + xhci->usb2_rhub.num_ports;
897 
898 	sch_array = kcalloc(num_usb_bus, sizeof(*sch_array), GFP_KERNEL);
899 	if (sch_array == NULL)
900 		return -ENOMEM;
901 
902 	mtk->sch_array = sch_array;
903 
904 	INIT_LIST_HEAD(&mtk->bw_ep_chk_list);
905 	hash_init(mtk->sch_ep_hash);
906 
907 	return 0;
908 }
909 
910 void xhci_mtk_sch_exit(struct xhci_hcd_mtk *mtk)
911 {
912 	kfree(mtk->sch_array);
913 }
914 
915 static int add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
916 			struct usb_host_endpoint *ep)
917 {
918 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
919 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
920 	struct xhci_ep_ctx *ep_ctx;
921 	struct xhci_virt_device *virt_dev;
922 	struct mu3h_sch_ep_info *sch_ep;
923 	unsigned int ep_index;
924 
925 	virt_dev = xhci->devs[udev->slot_id];
926 	ep_index = xhci_get_endpoint_index(&ep->desc);
927 	ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
928 
929 	if (!need_bw_sch(udev, ep)) {
930 		/*
931 		 * set @bpkts to 1 if it is LS or FS periodic endpoint, and its
932 		 * device does not connected through an external HS hub
933 		 */
934 		if (usb_endpoint_xfer_int(&ep->desc)
935 			|| usb_endpoint_xfer_isoc(&ep->desc))
936 			ep_ctx->reserved[0] = cpu_to_le32(EP_BPKTS(1));
937 
938 		return 0;
939 	}
940 
941 	xhci_dbg(xhci, "%s %s\n", __func__, decode_ep(ep, udev->speed));
942 
943 	sch_ep = create_sch_ep(mtk, udev, ep, ep_ctx);
944 	if (IS_ERR_OR_NULL(sch_ep))
945 		return -ENOMEM;
946 
947 	setup_sch_info(ep_ctx, sch_ep);
948 
949 	list_add_tail(&sch_ep->endpoint, &mtk->bw_ep_chk_list);
950 	hash_add(mtk->sch_ep_hash, &sch_ep->hentry, (unsigned long)ep);
951 
952 	return 0;
953 }
954 
955 static void drop_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
956 			  struct usb_host_endpoint *ep)
957 {
958 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
959 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
960 	struct mu3h_sch_ep_info *sch_ep;
961 	struct hlist_node *hn;
962 
963 	if (!need_bw_sch(udev, ep))
964 		return;
965 
966 	xhci_dbg(xhci, "%s %s\n", __func__, decode_ep(ep, udev->speed));
967 
968 	hash_for_each_possible_safe(mtk->sch_ep_hash, sch_ep,
969 				    hn, hentry, (unsigned long)ep) {
970 		if (sch_ep->ep == ep) {
971 			destroy_sch_ep(mtk, udev, sch_ep);
972 			break;
973 		}
974 	}
975 }
976 
977 int xhci_mtk_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
978 {
979 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
980 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
981 	struct xhci_virt_device *virt_dev = xhci->devs[udev->slot_id];
982 	struct mu3h_sch_ep_info *sch_ep;
983 	int ret;
984 
985 	xhci_dbg(xhci, "%s() udev %s\n", __func__, dev_name(&udev->dev));
986 
987 	list_for_each_entry(sch_ep, &mtk->bw_ep_chk_list, endpoint) {
988 		struct xhci_ep_ctx *ep_ctx;
989 		struct usb_host_endpoint *ep = sch_ep->ep;
990 		unsigned int ep_index = xhci_get_endpoint_index(&ep->desc);
991 
992 		ret = check_sch_bw(sch_ep);
993 		if (ret) {
994 			xhci_err(xhci, "Not enough bandwidth! (%s)\n",
995 				 sch_error_string(-ret));
996 			return -ENOSPC;
997 		}
998 
999 		ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
1000 		ep_ctx->reserved[0] = cpu_to_le32(EP_BPKTS(sch_ep->pkts)
1001 			| EP_BCSCOUNT(sch_ep->cs_count)
1002 			| EP_BBM(sch_ep->burst_mode));
1003 		ep_ctx->reserved[1] = cpu_to_le32(EP_BOFFSET(sch_ep->offset)
1004 			| EP_BREPEAT(sch_ep->repeat));
1005 
1006 		xhci_dbg(xhci, " PKTS:%x, CSCOUNT:%x, BM:%x, OFFSET:%x, REPEAT:%x\n",
1007 			sch_ep->pkts, sch_ep->cs_count, sch_ep->burst_mode,
1008 			sch_ep->offset, sch_ep->repeat);
1009 	}
1010 
1011 	ret = xhci_check_bandwidth(hcd, udev);
1012 	if (!ret)
1013 		list_del_init(&mtk->bw_ep_chk_list);
1014 
1015 	return ret;
1016 }
1017 
1018 void xhci_mtk_reset_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
1019 {
1020 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
1021 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
1022 	struct mu3h_sch_ep_info *sch_ep, *tmp;
1023 
1024 	xhci_dbg(xhci, "%s() udev %s\n", __func__, dev_name(&udev->dev));
1025 
1026 	list_for_each_entry_safe(sch_ep, tmp, &mtk->bw_ep_chk_list, endpoint)
1027 		destroy_sch_ep(mtk, udev, sch_ep);
1028 
1029 	xhci_reset_bandwidth(hcd, udev);
1030 }
1031 
1032 int xhci_mtk_add_ep(struct usb_hcd *hcd, struct usb_device *udev,
1033 		    struct usb_host_endpoint *ep)
1034 {
1035 	int ret;
1036 
1037 	ret = xhci_add_endpoint(hcd, udev, ep);
1038 	if (ret)
1039 		return ret;
1040 
1041 	if (ep->hcpriv)
1042 		ret = add_ep_quirk(hcd, udev, ep);
1043 
1044 	return ret;
1045 }
1046 
1047 int xhci_mtk_drop_ep(struct usb_hcd *hcd, struct usb_device *udev,
1048 		     struct usb_host_endpoint *ep)
1049 {
1050 	int ret;
1051 
1052 	ret = xhci_drop_endpoint(hcd, udev, ep);
1053 	if (ret)
1054 		return ret;
1055 
1056 	/* needn't check @ep->hcpriv, xhci_endpoint_disable set it NULL */
1057 	drop_ep_quirk(hcd, udev, ep);
1058 
1059 	return 0;
1060 }
1061