xref: /openbmc/linux/drivers/usb/host/xhci-mtk-sch.c (revision 8730046c)
1 /*
2  * Copyright (c) 2015 MediaTek Inc.
3  * Author:
4  *  Zhigang.Wei <zhigang.wei@mediatek.com>
5  *  Chunfeng.Yun <chunfeng.yun@mediatek.com>
6  *
7  * This software is licensed under the terms of the GNU General Public
8  * License version 2, as published by the Free Software Foundation, and
9  * may be copied, distributed, and modified under those terms.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  */
17 
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/slab.h>
21 
22 #include "xhci.h"
23 #include "xhci-mtk.h"
24 
25 #define SS_BW_BOUNDARY	51000
26 /* table 5-5. High-speed Isoc Transaction Limits in usb_20 spec */
27 #define HS_BW_BOUNDARY	6144
28 /* usb2 spec section11.18.1: at most 188 FS bytes per microframe */
29 #define FS_PAYLOAD_MAX 188
30 
31 /* mtk scheduler bitmasks */
32 #define EP_BPKTS(p)	((p) & 0x3f)
33 #define EP_BCSCOUNT(p)	(((p) & 0x7) << 8)
34 #define EP_BBM(p)	((p) << 11)
35 #define EP_BOFFSET(p)	((p) & 0x3fff)
36 #define EP_BREPEAT(p)	(((p) & 0x7fff) << 16)
37 
38 static int is_fs_or_ls(enum usb_device_speed speed)
39 {
40 	return speed == USB_SPEED_FULL || speed == USB_SPEED_LOW;
41 }
42 
43 /*
44 * get the index of bandwidth domains array which @ep belongs to.
45 *
46 * the bandwidth domain array is saved to @sch_array of struct xhci_hcd_mtk,
47 * each HS root port is treated as a single bandwidth domain,
48 * but each SS root port is treated as two bandwidth domains, one for IN eps,
49 * one for OUT eps.
50 * @real_port value is defined as follow according to xHCI spec:
51 * 1 for SSport0, ..., N+1 for SSportN, N+2 for HSport0, N+3 for HSport1, etc
52 * so the bandwidth domain array is organized as follow for simplification:
53 * SSport0-OUT, SSport0-IN, ..., SSportX-OUT, SSportX-IN, HSport0, ..., HSportY
54 */
55 static int get_bw_index(struct xhci_hcd *xhci, struct usb_device *udev,
56 	struct usb_host_endpoint *ep)
57 {
58 	struct xhci_virt_device *virt_dev;
59 	int bw_index;
60 
61 	virt_dev = xhci->devs[udev->slot_id];
62 
63 	if (udev->speed == USB_SPEED_SUPER) {
64 		if (usb_endpoint_dir_out(&ep->desc))
65 			bw_index = (virt_dev->real_port - 1) * 2;
66 		else
67 			bw_index = (virt_dev->real_port - 1) * 2 + 1;
68 	} else {
69 		/* add one more for each SS port */
70 		bw_index = virt_dev->real_port + xhci->num_usb3_ports - 1;
71 	}
72 
73 	return bw_index;
74 }
75 
76 static void setup_sch_info(struct usb_device *udev,
77 		struct xhci_ep_ctx *ep_ctx, struct mu3h_sch_ep_info *sch_ep)
78 {
79 	u32 ep_type;
80 	u32 ep_interval;
81 	u32 max_packet_size;
82 	u32 max_burst;
83 	u32 mult;
84 	u32 esit_pkts;
85 
86 	ep_type = CTX_TO_EP_TYPE(le32_to_cpu(ep_ctx->ep_info2));
87 	ep_interval = CTX_TO_EP_INTERVAL(le32_to_cpu(ep_ctx->ep_info));
88 	max_packet_size = MAX_PACKET_DECODED(le32_to_cpu(ep_ctx->ep_info2));
89 	max_burst = CTX_TO_MAX_BURST(le32_to_cpu(ep_ctx->ep_info2));
90 	mult = CTX_TO_EP_MULT(le32_to_cpu(ep_ctx->ep_info));
91 
92 	sch_ep->esit = 1 << ep_interval;
93 	sch_ep->offset = 0;
94 	sch_ep->burst_mode = 0;
95 
96 	if (udev->speed == USB_SPEED_HIGH) {
97 		sch_ep->cs_count = 0;
98 
99 		/*
100 		 * usb_20 spec section5.9
101 		 * a single microframe is enough for HS synchromous endpoints
102 		 * in a interval
103 		 */
104 		sch_ep->num_budget_microframes = 1;
105 		sch_ep->repeat = 0;
106 
107 		/*
108 		 * xHCI spec section6.2.3.4
109 		 * @max_burst is the number of additional transactions
110 		 * opportunities per microframe
111 		 */
112 		sch_ep->pkts = max_burst + 1;
113 		sch_ep->bw_cost_per_microframe = max_packet_size * sch_ep->pkts;
114 	} else if (udev->speed == USB_SPEED_SUPER) {
115 		/* usb3_r1 spec section4.4.7 & 4.4.8 */
116 		sch_ep->cs_count = 0;
117 		esit_pkts = (mult + 1) * (max_burst + 1);
118 		if (ep_type == INT_IN_EP || ep_type == INT_OUT_EP) {
119 			sch_ep->pkts = esit_pkts;
120 			sch_ep->num_budget_microframes = 1;
121 			sch_ep->repeat = 0;
122 		}
123 
124 		if (ep_type == ISOC_IN_EP || ep_type == ISOC_OUT_EP) {
125 			if (esit_pkts <= sch_ep->esit)
126 				sch_ep->pkts = 1;
127 			else
128 				sch_ep->pkts = roundup_pow_of_two(esit_pkts)
129 					/ sch_ep->esit;
130 
131 			sch_ep->num_budget_microframes =
132 				DIV_ROUND_UP(esit_pkts, sch_ep->pkts);
133 
134 			if (sch_ep->num_budget_microframes > 1)
135 				sch_ep->repeat = 1;
136 			else
137 				sch_ep->repeat = 0;
138 		}
139 		sch_ep->bw_cost_per_microframe = max_packet_size * sch_ep->pkts;
140 	} else if (is_fs_or_ls(udev->speed)) {
141 
142 		/*
143 		 * usb_20 spec section11.18.4
144 		 * assume worst cases
145 		 */
146 		sch_ep->repeat = 0;
147 		sch_ep->pkts = 1; /* at most one packet for each microframe */
148 		if (ep_type == INT_IN_EP || ep_type == INT_OUT_EP) {
149 			sch_ep->cs_count = 3; /* at most need 3 CS*/
150 			/* one for SS and one for budgeted transaction */
151 			sch_ep->num_budget_microframes = sch_ep->cs_count + 2;
152 			sch_ep->bw_cost_per_microframe = max_packet_size;
153 		}
154 		if (ep_type == ISOC_OUT_EP) {
155 
156 			/*
157 			 * the best case FS budget assumes that 188 FS bytes
158 			 * occur in each microframe
159 			 */
160 			sch_ep->num_budget_microframes = DIV_ROUND_UP(
161 				max_packet_size, FS_PAYLOAD_MAX);
162 			sch_ep->bw_cost_per_microframe = FS_PAYLOAD_MAX;
163 			sch_ep->cs_count = sch_ep->num_budget_microframes;
164 		}
165 		if (ep_type == ISOC_IN_EP) {
166 			/* at most need additional two CS. */
167 			sch_ep->cs_count = DIV_ROUND_UP(
168 				max_packet_size, FS_PAYLOAD_MAX) + 2;
169 			sch_ep->num_budget_microframes = sch_ep->cs_count + 2;
170 			sch_ep->bw_cost_per_microframe = FS_PAYLOAD_MAX;
171 		}
172 	}
173 }
174 
175 /* Get maximum bandwidth when we schedule at offset slot. */
176 static u32 get_max_bw(struct mu3h_sch_bw_info *sch_bw,
177 	struct mu3h_sch_ep_info *sch_ep, u32 offset)
178 {
179 	u32 num_esit;
180 	u32 max_bw = 0;
181 	int i;
182 	int j;
183 
184 	num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
185 	for (i = 0; i < num_esit; i++) {
186 		u32 base = offset + i * sch_ep->esit;
187 
188 		for (j = 0; j < sch_ep->num_budget_microframes; j++) {
189 			if (sch_bw->bus_bw[base + j] > max_bw)
190 				max_bw = sch_bw->bus_bw[base + j];
191 		}
192 	}
193 	return max_bw;
194 }
195 
196 static void update_bus_bw(struct mu3h_sch_bw_info *sch_bw,
197 	struct mu3h_sch_ep_info *sch_ep, int bw_cost)
198 {
199 	u32 num_esit;
200 	u32 base;
201 	int i;
202 	int j;
203 
204 	num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
205 	for (i = 0; i < num_esit; i++) {
206 		base = sch_ep->offset + i * sch_ep->esit;
207 		for (j = 0; j < sch_ep->num_budget_microframes; j++)
208 			sch_bw->bus_bw[base + j] += bw_cost;
209 	}
210 }
211 
212 static int check_sch_bw(struct usb_device *udev,
213 	struct mu3h_sch_bw_info *sch_bw, struct mu3h_sch_ep_info *sch_ep)
214 {
215 	u32 offset;
216 	u32 esit;
217 	u32 num_budget_microframes;
218 	u32 min_bw;
219 	u32 min_index;
220 	u32 worst_bw;
221 	u32 bw_boundary;
222 
223 	if (sch_ep->esit > XHCI_MTK_MAX_ESIT)
224 		sch_ep->esit = XHCI_MTK_MAX_ESIT;
225 
226 	esit = sch_ep->esit;
227 	num_budget_microframes = sch_ep->num_budget_microframes;
228 
229 	/*
230 	 * Search through all possible schedule microframes.
231 	 * and find a microframe where its worst bandwidth is minimum.
232 	 */
233 	min_bw = ~0;
234 	min_index = 0;
235 	for (offset = 0; offset < esit; offset++) {
236 		if ((offset + num_budget_microframes) > sch_ep->esit)
237 			break;
238 
239 		/*
240 		 * usb_20 spec section11.18:
241 		 * must never schedule Start-Split in Y6
242 		 */
243 		if (is_fs_or_ls(udev->speed) && (offset % 8 == 6))
244 			continue;
245 
246 		worst_bw = get_max_bw(sch_bw, sch_ep, offset);
247 		if (min_bw > worst_bw) {
248 			min_bw = worst_bw;
249 			min_index = offset;
250 		}
251 		if (min_bw == 0)
252 			break;
253 	}
254 	sch_ep->offset = min_index;
255 
256 	bw_boundary = (udev->speed == USB_SPEED_SUPER)
257 				? SS_BW_BOUNDARY : HS_BW_BOUNDARY;
258 
259 	/* check bandwidth */
260 	if (min_bw + sch_ep->bw_cost_per_microframe > bw_boundary)
261 		return -ERANGE;
262 
263 	/* update bus bandwidth info */
264 	update_bus_bw(sch_bw, sch_ep, sch_ep->bw_cost_per_microframe);
265 
266 	return 0;
267 }
268 
269 static bool need_bw_sch(struct usb_host_endpoint *ep,
270 	enum usb_device_speed speed, int has_tt)
271 {
272 	/* only for periodic endpoints */
273 	if (usb_endpoint_xfer_control(&ep->desc)
274 		|| usb_endpoint_xfer_bulk(&ep->desc))
275 		return false;
276 
277 	/*
278 	 * for LS & FS periodic endpoints which its device is not behind
279 	 * a TT are also ignored, root-hub will schedule them directly,
280 	 * but need set @bpkts field of endpoint context to 1.
281 	 */
282 	if (is_fs_or_ls(speed) && !has_tt)
283 		return false;
284 
285 	return true;
286 }
287 
288 int xhci_mtk_sch_init(struct xhci_hcd_mtk *mtk)
289 {
290 	struct mu3h_sch_bw_info *sch_array;
291 	int num_usb_bus;
292 	int i;
293 
294 	/* ss IN and OUT are separated */
295 	num_usb_bus = mtk->num_u3_ports * 2 + mtk->num_u2_ports;
296 
297 	sch_array = kcalloc(num_usb_bus, sizeof(*sch_array), GFP_KERNEL);
298 	if (sch_array == NULL)
299 		return -ENOMEM;
300 
301 	for (i = 0; i < num_usb_bus; i++)
302 		INIT_LIST_HEAD(&sch_array[i].bw_ep_list);
303 
304 	mtk->sch_array = sch_array;
305 
306 	return 0;
307 }
308 EXPORT_SYMBOL_GPL(xhci_mtk_sch_init);
309 
310 void xhci_mtk_sch_exit(struct xhci_hcd_mtk *mtk)
311 {
312 	kfree(mtk->sch_array);
313 }
314 EXPORT_SYMBOL_GPL(xhci_mtk_sch_exit);
315 
316 int xhci_mtk_add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
317 		struct usb_host_endpoint *ep)
318 {
319 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
320 	struct xhci_hcd *xhci;
321 	struct xhci_ep_ctx *ep_ctx;
322 	struct xhci_slot_ctx *slot_ctx;
323 	struct xhci_virt_device *virt_dev;
324 	struct mu3h_sch_bw_info *sch_bw;
325 	struct mu3h_sch_ep_info *sch_ep;
326 	struct mu3h_sch_bw_info *sch_array;
327 	unsigned int ep_index;
328 	int bw_index;
329 	int ret = 0;
330 
331 	xhci = hcd_to_xhci(hcd);
332 	virt_dev = xhci->devs[udev->slot_id];
333 	ep_index = xhci_get_endpoint_index(&ep->desc);
334 	slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
335 	ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
336 	sch_array = mtk->sch_array;
337 
338 	xhci_dbg(xhci, "%s() type:%d, speed:%d, mpkt:%d, dir:%d, ep:%p\n",
339 		__func__, usb_endpoint_type(&ep->desc), udev->speed,
340 		usb_endpoint_maxp(&ep->desc),
341 		usb_endpoint_dir_in(&ep->desc), ep);
342 
343 	if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT)) {
344 		/*
345 		 * set @bpkts to 1 if it is LS or FS periodic endpoint, and its
346 		 * device does not connected through an external HS hub
347 		 */
348 		if (usb_endpoint_xfer_int(&ep->desc)
349 			|| usb_endpoint_xfer_isoc(&ep->desc))
350 			ep_ctx->reserved[0] |= cpu_to_le32(EP_BPKTS(1));
351 
352 		return 0;
353 	}
354 
355 	bw_index = get_bw_index(xhci, udev, ep);
356 	sch_bw = &sch_array[bw_index];
357 
358 	sch_ep = kzalloc(sizeof(struct mu3h_sch_ep_info), GFP_NOIO);
359 	if (!sch_ep)
360 		return -ENOMEM;
361 
362 	setup_sch_info(udev, ep_ctx, sch_ep);
363 
364 	ret = check_sch_bw(udev, sch_bw, sch_ep);
365 	if (ret) {
366 		xhci_err(xhci, "Not enough bandwidth!\n");
367 		kfree(sch_ep);
368 		return -ENOSPC;
369 	}
370 
371 	list_add_tail(&sch_ep->endpoint, &sch_bw->bw_ep_list);
372 	sch_ep->ep = ep;
373 
374 	ep_ctx->reserved[0] |= cpu_to_le32(EP_BPKTS(sch_ep->pkts)
375 		| EP_BCSCOUNT(sch_ep->cs_count) | EP_BBM(sch_ep->burst_mode));
376 	ep_ctx->reserved[1] |= cpu_to_le32(EP_BOFFSET(sch_ep->offset)
377 		| EP_BREPEAT(sch_ep->repeat));
378 
379 	xhci_dbg(xhci, " PKTS:%x, CSCOUNT:%x, BM:%x, OFFSET:%x, REPEAT:%x\n",
380 			sch_ep->pkts, sch_ep->cs_count, sch_ep->burst_mode,
381 			sch_ep->offset, sch_ep->repeat);
382 
383 	return 0;
384 }
385 EXPORT_SYMBOL_GPL(xhci_mtk_add_ep_quirk);
386 
387 void xhci_mtk_drop_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
388 		struct usb_host_endpoint *ep)
389 {
390 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
391 	struct xhci_hcd *xhci;
392 	struct xhci_slot_ctx *slot_ctx;
393 	struct xhci_virt_device *virt_dev;
394 	struct mu3h_sch_bw_info *sch_array;
395 	struct mu3h_sch_bw_info *sch_bw;
396 	struct mu3h_sch_ep_info *sch_ep;
397 	int bw_index;
398 
399 	xhci = hcd_to_xhci(hcd);
400 	virt_dev = xhci->devs[udev->slot_id];
401 	slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
402 	sch_array = mtk->sch_array;
403 
404 	xhci_dbg(xhci, "%s() type:%d, speed:%d, mpks:%d, dir:%d, ep:%p\n",
405 		__func__, usb_endpoint_type(&ep->desc), udev->speed,
406 		usb_endpoint_maxp(&ep->desc),
407 		usb_endpoint_dir_in(&ep->desc), ep);
408 
409 	if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT))
410 		return;
411 
412 	bw_index = get_bw_index(xhci, udev, ep);
413 	sch_bw = &sch_array[bw_index];
414 
415 	list_for_each_entry(sch_ep, &sch_bw->bw_ep_list, endpoint) {
416 		if (sch_ep->ep == ep) {
417 			update_bus_bw(sch_bw, sch_ep,
418 				-sch_ep->bw_cost_per_microframe);
419 			list_del(&sch_ep->endpoint);
420 			kfree(sch_ep);
421 			break;
422 		}
423 	}
424 }
425 EXPORT_SYMBOL_GPL(xhci_mtk_drop_ep_quirk);
426