xref: /openbmc/linux/drivers/usb/host/xhci-mtk-sch.c (revision cfbb9be8)
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 SS_BW_BOUNDARY	51000
17 /* table 5-5. High-speed Isoc Transaction Limits in usb_20 spec */
18 #define HS_BW_BOUNDARY	6144
19 /* usb2 spec section11.18.1: at most 188 FS bytes per microframe */
20 #define FS_PAYLOAD_MAX 188
21 
22 /* mtk scheduler bitmasks */
23 #define EP_BPKTS(p)	((p) & 0x3f)
24 #define EP_BCSCOUNT(p)	(((p) & 0x7) << 8)
25 #define EP_BBM(p)	((p) << 11)
26 #define EP_BOFFSET(p)	((p) & 0x3fff)
27 #define EP_BREPEAT(p)	(((p) & 0x7fff) << 16)
28 
29 static int is_fs_or_ls(enum usb_device_speed speed)
30 {
31 	return speed == USB_SPEED_FULL || speed == USB_SPEED_LOW;
32 }
33 
34 /*
35 * get the index of bandwidth domains array which @ep belongs to.
36 *
37 * the bandwidth domain array is saved to @sch_array of struct xhci_hcd_mtk,
38 * each HS root port is treated as a single bandwidth domain,
39 * but each SS root port is treated as two bandwidth domains, one for IN eps,
40 * one for OUT eps.
41 * @real_port value is defined as follow according to xHCI spec:
42 * 1 for SSport0, ..., N+1 for SSportN, N+2 for HSport0, N+3 for HSport1, etc
43 * so the bandwidth domain array is organized as follow for simplification:
44 * SSport0-OUT, SSport0-IN, ..., SSportX-OUT, SSportX-IN, HSport0, ..., HSportY
45 */
46 static int get_bw_index(struct xhci_hcd *xhci, struct usb_device *udev,
47 	struct usb_host_endpoint *ep)
48 {
49 	struct xhci_virt_device *virt_dev;
50 	int bw_index;
51 
52 	virt_dev = xhci->devs[udev->slot_id];
53 
54 	if (udev->speed == USB_SPEED_SUPER) {
55 		if (usb_endpoint_dir_out(&ep->desc))
56 			bw_index = (virt_dev->real_port - 1) * 2;
57 		else
58 			bw_index = (virt_dev->real_port - 1) * 2 + 1;
59 	} else {
60 		/* add one more for each SS port */
61 		bw_index = virt_dev->real_port + xhci->num_usb3_ports - 1;
62 	}
63 
64 	return bw_index;
65 }
66 
67 static void setup_sch_info(struct usb_device *udev,
68 		struct xhci_ep_ctx *ep_ctx, struct mu3h_sch_ep_info *sch_ep)
69 {
70 	u32 ep_type;
71 	u32 ep_interval;
72 	u32 max_packet_size;
73 	u32 max_burst;
74 	u32 mult;
75 	u32 esit_pkts;
76 
77 	ep_type = CTX_TO_EP_TYPE(le32_to_cpu(ep_ctx->ep_info2));
78 	ep_interval = CTX_TO_EP_INTERVAL(le32_to_cpu(ep_ctx->ep_info));
79 	max_packet_size = MAX_PACKET_DECODED(le32_to_cpu(ep_ctx->ep_info2));
80 	max_burst = CTX_TO_MAX_BURST(le32_to_cpu(ep_ctx->ep_info2));
81 	mult = CTX_TO_EP_MULT(le32_to_cpu(ep_ctx->ep_info));
82 
83 	sch_ep->esit = 1 << ep_interval;
84 	sch_ep->offset = 0;
85 	sch_ep->burst_mode = 0;
86 
87 	if (udev->speed == USB_SPEED_HIGH) {
88 		sch_ep->cs_count = 0;
89 
90 		/*
91 		 * usb_20 spec section5.9
92 		 * a single microframe is enough for HS synchromous endpoints
93 		 * in a interval
94 		 */
95 		sch_ep->num_budget_microframes = 1;
96 		sch_ep->repeat = 0;
97 
98 		/*
99 		 * xHCI spec section6.2.3.4
100 		 * @max_burst is the number of additional transactions
101 		 * opportunities per microframe
102 		 */
103 		sch_ep->pkts = max_burst + 1;
104 		sch_ep->bw_cost_per_microframe = max_packet_size * sch_ep->pkts;
105 	} else if (udev->speed == USB_SPEED_SUPER) {
106 		/* usb3_r1 spec section4.4.7 & 4.4.8 */
107 		sch_ep->cs_count = 0;
108 		esit_pkts = (mult + 1) * (max_burst + 1);
109 		if (ep_type == INT_IN_EP || ep_type == INT_OUT_EP) {
110 			sch_ep->pkts = esit_pkts;
111 			sch_ep->num_budget_microframes = 1;
112 			sch_ep->repeat = 0;
113 		}
114 
115 		if (ep_type == ISOC_IN_EP || ep_type == ISOC_OUT_EP) {
116 			if (esit_pkts <= sch_ep->esit)
117 				sch_ep->pkts = 1;
118 			else
119 				sch_ep->pkts = roundup_pow_of_two(esit_pkts)
120 					/ sch_ep->esit;
121 
122 			sch_ep->num_budget_microframes =
123 				DIV_ROUND_UP(esit_pkts, sch_ep->pkts);
124 
125 			if (sch_ep->num_budget_microframes > 1)
126 				sch_ep->repeat = 1;
127 			else
128 				sch_ep->repeat = 0;
129 		}
130 		sch_ep->bw_cost_per_microframe = max_packet_size * sch_ep->pkts;
131 	} else if (is_fs_or_ls(udev->speed)) {
132 
133 		/*
134 		 * usb_20 spec section11.18.4
135 		 * assume worst cases
136 		 */
137 		sch_ep->repeat = 0;
138 		sch_ep->pkts = 1; /* at most one packet for each microframe */
139 		if (ep_type == INT_IN_EP || ep_type == INT_OUT_EP) {
140 			sch_ep->cs_count = 3; /* at most need 3 CS*/
141 			/* one for SS and one for budgeted transaction */
142 			sch_ep->num_budget_microframes = sch_ep->cs_count + 2;
143 			sch_ep->bw_cost_per_microframe = max_packet_size;
144 		}
145 		if (ep_type == ISOC_OUT_EP) {
146 
147 			/*
148 			 * the best case FS budget assumes that 188 FS bytes
149 			 * occur in each microframe
150 			 */
151 			sch_ep->num_budget_microframes = DIV_ROUND_UP(
152 				max_packet_size, FS_PAYLOAD_MAX);
153 			sch_ep->bw_cost_per_microframe = FS_PAYLOAD_MAX;
154 			sch_ep->cs_count = sch_ep->num_budget_microframes;
155 		}
156 		if (ep_type == ISOC_IN_EP) {
157 			/* at most need additional two CS. */
158 			sch_ep->cs_count = DIV_ROUND_UP(
159 				max_packet_size, FS_PAYLOAD_MAX) + 2;
160 			sch_ep->num_budget_microframes = sch_ep->cs_count + 2;
161 			sch_ep->bw_cost_per_microframe = FS_PAYLOAD_MAX;
162 		}
163 	}
164 }
165 
166 /* Get maximum bandwidth when we schedule at offset slot. */
167 static u32 get_max_bw(struct mu3h_sch_bw_info *sch_bw,
168 	struct mu3h_sch_ep_info *sch_ep, u32 offset)
169 {
170 	u32 num_esit;
171 	u32 max_bw = 0;
172 	int i;
173 	int j;
174 
175 	num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
176 	for (i = 0; i < num_esit; i++) {
177 		u32 base = offset + i * sch_ep->esit;
178 
179 		for (j = 0; j < sch_ep->num_budget_microframes; j++) {
180 			if (sch_bw->bus_bw[base + j] > max_bw)
181 				max_bw = sch_bw->bus_bw[base + j];
182 		}
183 	}
184 	return max_bw;
185 }
186 
187 static void update_bus_bw(struct mu3h_sch_bw_info *sch_bw,
188 	struct mu3h_sch_ep_info *sch_ep, int bw_cost)
189 {
190 	u32 num_esit;
191 	u32 base;
192 	int i;
193 	int j;
194 
195 	num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
196 	for (i = 0; i < num_esit; i++) {
197 		base = sch_ep->offset + i * sch_ep->esit;
198 		for (j = 0; j < sch_ep->num_budget_microframes; j++)
199 			sch_bw->bus_bw[base + j] += bw_cost;
200 	}
201 }
202 
203 static int check_sch_bw(struct usb_device *udev,
204 	struct mu3h_sch_bw_info *sch_bw, struct mu3h_sch_ep_info *sch_ep)
205 {
206 	u32 offset;
207 	u32 esit;
208 	u32 num_budget_microframes;
209 	u32 min_bw;
210 	u32 min_index;
211 	u32 worst_bw;
212 	u32 bw_boundary;
213 
214 	if (sch_ep->esit > XHCI_MTK_MAX_ESIT)
215 		sch_ep->esit = XHCI_MTK_MAX_ESIT;
216 
217 	esit = sch_ep->esit;
218 	num_budget_microframes = sch_ep->num_budget_microframes;
219 
220 	/*
221 	 * Search through all possible schedule microframes.
222 	 * and find a microframe where its worst bandwidth is minimum.
223 	 */
224 	min_bw = ~0;
225 	min_index = 0;
226 	for (offset = 0; offset < esit; offset++) {
227 		if ((offset + num_budget_microframes) > sch_ep->esit)
228 			break;
229 
230 		/*
231 		 * usb_20 spec section11.18:
232 		 * must never schedule Start-Split in Y6
233 		 */
234 		if (is_fs_or_ls(udev->speed) && (offset % 8 == 6))
235 			continue;
236 
237 		worst_bw = get_max_bw(sch_bw, sch_ep, offset);
238 		if (min_bw > worst_bw) {
239 			min_bw = worst_bw;
240 			min_index = offset;
241 		}
242 		if (min_bw == 0)
243 			break;
244 	}
245 	sch_ep->offset = min_index;
246 
247 	bw_boundary = (udev->speed == USB_SPEED_SUPER)
248 				? SS_BW_BOUNDARY : HS_BW_BOUNDARY;
249 
250 	/* check bandwidth */
251 	if (min_bw + sch_ep->bw_cost_per_microframe > bw_boundary)
252 		return -ERANGE;
253 
254 	/* update bus bandwidth info */
255 	update_bus_bw(sch_bw, sch_ep, sch_ep->bw_cost_per_microframe);
256 
257 	return 0;
258 }
259 
260 static bool need_bw_sch(struct usb_host_endpoint *ep,
261 	enum usb_device_speed speed, int has_tt)
262 {
263 	/* only for periodic endpoints */
264 	if (usb_endpoint_xfer_control(&ep->desc)
265 		|| usb_endpoint_xfer_bulk(&ep->desc))
266 		return false;
267 
268 	/*
269 	 * for LS & FS periodic endpoints which its device is not behind
270 	 * a TT are also ignored, root-hub will schedule them directly,
271 	 * but need set @bpkts field of endpoint context to 1.
272 	 */
273 	if (is_fs_or_ls(speed) && !has_tt)
274 		return false;
275 
276 	return true;
277 }
278 
279 int xhci_mtk_sch_init(struct xhci_hcd_mtk *mtk)
280 {
281 	struct xhci_hcd *xhci = hcd_to_xhci(mtk->hcd);
282 	struct mu3h_sch_bw_info *sch_array;
283 	int num_usb_bus;
284 	int i;
285 
286 	/* ss IN and OUT are separated */
287 	num_usb_bus = xhci->num_usb3_ports * 2 + xhci->num_usb2_ports;
288 
289 	sch_array = kcalloc(num_usb_bus, sizeof(*sch_array), GFP_KERNEL);
290 	if (sch_array == NULL)
291 		return -ENOMEM;
292 
293 	for (i = 0; i < num_usb_bus; i++)
294 		INIT_LIST_HEAD(&sch_array[i].bw_ep_list);
295 
296 	mtk->sch_array = sch_array;
297 
298 	return 0;
299 }
300 EXPORT_SYMBOL_GPL(xhci_mtk_sch_init);
301 
302 void xhci_mtk_sch_exit(struct xhci_hcd_mtk *mtk)
303 {
304 	kfree(mtk->sch_array);
305 }
306 EXPORT_SYMBOL_GPL(xhci_mtk_sch_exit);
307 
308 int xhci_mtk_add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
309 		struct usb_host_endpoint *ep)
310 {
311 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
312 	struct xhci_hcd *xhci;
313 	struct xhci_ep_ctx *ep_ctx;
314 	struct xhci_slot_ctx *slot_ctx;
315 	struct xhci_virt_device *virt_dev;
316 	struct mu3h_sch_bw_info *sch_bw;
317 	struct mu3h_sch_ep_info *sch_ep;
318 	struct mu3h_sch_bw_info *sch_array;
319 	unsigned int ep_index;
320 	int bw_index;
321 	int ret = 0;
322 
323 	xhci = hcd_to_xhci(hcd);
324 	virt_dev = xhci->devs[udev->slot_id];
325 	ep_index = xhci_get_endpoint_index(&ep->desc);
326 	slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
327 	ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
328 	sch_array = mtk->sch_array;
329 
330 	xhci_dbg(xhci, "%s() type:%d, speed:%d, mpkt:%d, dir:%d, ep:%p\n",
331 		__func__, usb_endpoint_type(&ep->desc), udev->speed,
332 		usb_endpoint_maxp(&ep->desc),
333 		usb_endpoint_dir_in(&ep->desc), ep);
334 
335 	if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT)) {
336 		/*
337 		 * set @bpkts to 1 if it is LS or FS periodic endpoint, and its
338 		 * device does not connected through an external HS hub
339 		 */
340 		if (usb_endpoint_xfer_int(&ep->desc)
341 			|| usb_endpoint_xfer_isoc(&ep->desc))
342 			ep_ctx->reserved[0] |= cpu_to_le32(EP_BPKTS(1));
343 
344 		return 0;
345 	}
346 
347 	bw_index = get_bw_index(xhci, udev, ep);
348 	sch_bw = &sch_array[bw_index];
349 
350 	sch_ep = kzalloc(sizeof(struct mu3h_sch_ep_info), GFP_NOIO);
351 	if (!sch_ep)
352 		return -ENOMEM;
353 
354 	setup_sch_info(udev, ep_ctx, sch_ep);
355 
356 	ret = check_sch_bw(udev, sch_bw, sch_ep);
357 	if (ret) {
358 		xhci_err(xhci, "Not enough bandwidth!\n");
359 		kfree(sch_ep);
360 		return -ENOSPC;
361 	}
362 
363 	list_add_tail(&sch_ep->endpoint, &sch_bw->bw_ep_list);
364 	sch_ep->ep = ep;
365 
366 	ep_ctx->reserved[0] |= cpu_to_le32(EP_BPKTS(sch_ep->pkts)
367 		| EP_BCSCOUNT(sch_ep->cs_count) | EP_BBM(sch_ep->burst_mode));
368 	ep_ctx->reserved[1] |= cpu_to_le32(EP_BOFFSET(sch_ep->offset)
369 		| EP_BREPEAT(sch_ep->repeat));
370 
371 	xhci_dbg(xhci, " PKTS:%x, CSCOUNT:%x, BM:%x, OFFSET:%x, REPEAT:%x\n",
372 			sch_ep->pkts, sch_ep->cs_count, sch_ep->burst_mode,
373 			sch_ep->offset, sch_ep->repeat);
374 
375 	return 0;
376 }
377 EXPORT_SYMBOL_GPL(xhci_mtk_add_ep_quirk);
378 
379 void xhci_mtk_drop_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
380 		struct usb_host_endpoint *ep)
381 {
382 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
383 	struct xhci_hcd *xhci;
384 	struct xhci_slot_ctx *slot_ctx;
385 	struct xhci_virt_device *virt_dev;
386 	struct mu3h_sch_bw_info *sch_array;
387 	struct mu3h_sch_bw_info *sch_bw;
388 	struct mu3h_sch_ep_info *sch_ep;
389 	int bw_index;
390 
391 	xhci = hcd_to_xhci(hcd);
392 	virt_dev = xhci->devs[udev->slot_id];
393 	slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
394 	sch_array = mtk->sch_array;
395 
396 	xhci_dbg(xhci, "%s() type:%d, speed:%d, mpks:%d, dir:%d, ep:%p\n",
397 		__func__, usb_endpoint_type(&ep->desc), udev->speed,
398 		usb_endpoint_maxp(&ep->desc),
399 		usb_endpoint_dir_in(&ep->desc), ep);
400 
401 	if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT))
402 		return;
403 
404 	bw_index = get_bw_index(xhci, udev, ep);
405 	sch_bw = &sch_array[bw_index];
406 
407 	list_for_each_entry(sch_ep, &sch_bw->bw_ep_list, endpoint) {
408 		if (sch_ep->ep == ep) {
409 			update_bus_bw(sch_bw, sch_ep,
410 				-sch_ep->bw_cost_per_microframe);
411 			list_del(&sch_ep->endpoint);
412 			kfree(sch_ep);
413 			break;
414 		}
415 	}
416 }
417 EXPORT_SYMBOL_GPL(xhci_mtk_drop_ep_quirk);
418