aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/host/whci/asl.c
blob: 4d7078e50572260619f9dabfca4405884431f502 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
/*
 * Wireless Host Controller (WHC) asynchronous schedule management.
 *
 * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <linux/kernel.h>
#include <linux/dma-mapping.h>
#include <linux/uwb/umc.h>
#include <linux/usb.h>
#define D_LOCAL 0
#include <linux/uwb/debug.h>

#include "../../wusbcore/wusbhc.h"

#include "whcd.h"

#if D_LOCAL >= 4
static void dump_asl(struct whc *whc, const char *tag)
{
	struct device *dev = &whc->umc->dev;
	struct whc_qset *qset;

	d_printf(4, dev, "ASL %s\n", tag);

	list_for_each_entry(qset, &whc->async_list, list_node) {
		dump_qset(qset, dev);
	}
}
#else
static inline void dump_asl(struct whc *whc, const char *tag)
{
}
#endif


static void qset_get_next_prev(struct whc *whc, struct whc_qset *qset,
			       struct whc_qset **next, struct whc_qset **prev)
{
	struct list_head *n, *p;

	BUG_ON(list_empty(&whc->async_list));

	n = qset->list_node.next;
	if (n == &whc->async_list)
		n = n->next;
	p = qset->list_node.prev;
	if (p == &whc->async_list)
		p = p->prev;

	*next = container_of(n, struct whc_qset, list_node);
	*prev = container_of(p, struct whc_qset, list_node);

}

static void asl_qset_insert_begin(struct whc *whc, struct whc_qset *qset)
{
	list_move(&qset->list_node, &whc->async_list);
	qset->in_sw_list = true;
}

static void asl_qset_insert(struct whc *whc, struct whc_qset *qset)
{
	struct whc_qset *next, *prev;

	qset_clear(whc, qset);

	/* Link into ASL. */
	qset_get_next_prev(whc, qset, &next, &prev);
	whc_qset_set_link_ptr(&qset->qh.link, next->qset_dma);
	whc_qset_set_link_ptr(&prev->qh.link, qset->qset_dma);
	qset->in_hw_list = true;
}

static void asl_qset_remove(struct whc *whc, struct whc_qset *qset)
{
	struct whc_qset *prev, *next;

	qset_get_next_prev(whc, qset, &next, &prev);

	list_move(&qset->list_node, &whc->async_removed_list);
	qset->in_sw_list = false;

	/*
	 * No more qsets in the ASL?  The caller must stop the ASL as
	 * it's no longer valid.
	 */
	if (list_empty(&whc->async_list))
		return;

	/* Remove from ASL. */
	whc_qset_set_link_ptr(&prev->qh.link, next->qset_dma);
	qset->in_hw_list = false;
}

/**
 * process_qset - process any recently inactivated or halted qTDs in a
 * qset.
 *
 * After inactive qTDs are removed, new qTDs can be added if the
 * urb queue still contains URBs.
 *
 * Returns any additional WUSBCMD bits for the ASL sync command (i.e.,
 * WUSBCMD_ASYNC_QSET_RM if a halted qset was removed).
 */
static uint32_t process_qset(struct whc *whc, struct whc_qset *qset)
{
	enum whc_update update = 0;
	uint32_t status = 0;

	while (qset->ntds) {
		struct whc_qtd *td;
		int t;

		t = qset->td_start;
		td = &qset->qtd[qset->td_start];
		status = le32_to_cpu(td->status);

		/*
		 * Nothing to do with a still active qTD.
		 */
		if (status & QTD_STS_ACTIVE)
			break;

		if (status & QTD_STS_HALTED) {
			/* Ug, an error. */
			process_halted_qtd(whc, qset, td);
			goto done;
		}

		/* Mmm, a completed qTD. */
		process_inactive_qtd(whc, qset, td);
	}

	update |= qset_add_qtds(whc, qset);

done:
	/*
	 * Remove this qset from the ASL if requested, but only if has
	 * no qTDs.
	 */
	if (qset->remove && qset->ntds == 0) {
		asl_qset_remove(whc, qset);
		update |= WHC_UPDATE_REMOVED;
	}
	return update;
}

void asl_start(struct whc *whc)
{
	struct whc_qset *qset;

	qset = list_first_entry(&whc->async_list, struct whc_qset, list_node);

	le_writeq(qset->qset_dma | QH_LINK_NTDS(8), whc->base + WUSBASYNCLISTADDR);

	whc_write_wusbcmd(whc, WUSBCMD_ASYNC_EN, WUSBCMD_ASYNC_EN);
	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
		      WUSBSTS_ASYNC_SCHED, WUSBSTS_ASYNC_SCHED,
		      1000, "start ASL");
}

void asl_stop(struct whc *whc)
{
	whc_write_wusbcmd(whc, WUSBCMD_ASYNC_EN, 0);
	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
		      WUSBSTS_ASYNC_SCHED, 0,
		      1000, "stop ASL");
}

void asl_update(struct whc *whc, uint32_t wusbcmd)
{
	whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
	wait_event(whc->async_list_wq,
		   (le_readl(whc->base + WUSBCMD) & WUSBCMD_ASYNC_UPDATED) == 0);
}

/**
 * scan_async_work - scan the ASL for qsets to process.
 *
 * Process each qset in the ASL in turn and then signal the WHC that
 * the ASL has been updated.
 *
 * Then start, stop or update the asynchronous schedule as required.
 */
void scan_async_work(struct work_struct *work)
{
	struct whc *whc = container_of(work, struct whc, async_work);
	struct whc_qset *qset, *t;
	enum whc_update update = 0;

	spin_lock_irq(&whc->lock);

	dump_asl(whc, "before processing");

	/*
	 * Transerve the software list backwards so new qsets can be
	 * safely inserted into the ASL without making it non-circular.
	 */
	list_for_each_entry_safe_reverse(qset, t, &whc->async_list, list_node) {
		if (!qset->in_hw_list) {
			asl_qset_insert(whc, qset);
			update |= WHC_UPDATE_ADDED;
		}

		update |= process_qset(whc, qset);
	}

	dump_asl(whc, "after processing");

	spin_unlock_irq(&whc->lock);

	if (update) {
		uint32_t wusbcmd = WUSBCMD_ASYNC_UPDATED | WUSBCMD_ASYNC_SYNCED_DB;
		if (update & WHC_UPDATE_REMOVED)
			wusbcmd |= WUSBCMD_ASYNC_QSET_RM;
		asl_update(whc, wusbcmd);
	}

	/*
	 * Now that the ASL is updated, complete the removal of any
	 * removed qsets.
	 */
	spin_lock(&whc->lock);

	list_for_each_entry_safe(qset, t, &whc->async_removed_list, list_node) {
		qset_remove_complete(whc, qset);
	}

	spin_unlock(&whc->lock);
}

/**
 * asl_urb_enqueue - queue an URB onto the asynchronous list (ASL).
 * @whc: the WHCI host controller
 * @urb: the URB to enqueue
 * @mem_flags: flags for any memory allocations
 *
 * The qset for the endpoint is obtained and the urb queued on to it.
 *
 * Work is scheduled to update the hardware's view of the ASL.
 */
int asl_urb_enqueue(struct whc *whc, struct urb *urb, gfp_t mem_flags)
{
	struct whc_qset *qset;
	int err;
	unsigned long flags;

	spin_lock_irqsave(&whc->lock, flags);

	qset = get_qset(whc, urb, GFP_ATOMIC);
	if (qset == NULL)
		err = -ENOMEM;
	else
		err = qset_add_urb(whc, qset, urb, GFP_ATOMIC);
	if (!err) {
		usb_hcd_link_urb_to_ep(&whc->wusbhc.usb_hcd, urb);
		if (!qset->in_sw_list)
			asl_qset_insert_begin(whc, qset);
	}

	spin_unlock_irqrestore(&whc->lock, flags);

	if (!err)
		queue_work(whc->workqueue, &whc->async_work);

	return 0;
}

/**
 * asl_urb_dequeue - remove an URB (qset) from the async list.
 * @whc: the WHCI host controller
 * @urb: the URB to dequeue
 * @status: the current status of the URB
 *
 * URBs that do yet have qTDs can simply be removed from the software
 * queue, otherwise the qset must be removed from the ASL so the qTDs
 * can be removed.
 */
int asl_urb_dequeue(struct whc *whc, struct urb *urb, int status)
{
	struct whc_urb *wurb = urb->hcpriv;
	struct whc_qset *qset = wurb->qset;
	struct whc_std *std, *t;
	int ret;
	unsigned long flags;

	spin_lock_irqsave(&whc->lock, flags);

	ret = usb_hcd_check_unlink_urb(&whc->wusbhc.usb_hcd, urb, status);
	if (ret < 0)
		goto out;

	list_for_each_entry_safe(std, t, &qset->stds, list_node) {
		if (std->urb == urb)
			qset_free_std(whc, std);
		else
			std->qtd = NULL; /* so this std is re-added when the qset is */
	}

	asl_qset_remove(whc, qset);
	wurb->status = status;
	wurb->is_async = true;
	queue_work(whc->workqueue, &wurb->dequeue_work);

out:
	spin_unlock_irqrestore(&whc->lock, flags);

	return ret;
}

/**
 * asl_qset_delete - delete a qset from the ASL
 */
void asl_qset_delete(struct whc *whc, struct whc_qset *qset)
{
	qset->remove = 1;
	queue_work(whc->workqueue, &whc->async_work);
	qset_delete(whc, qset);
}

/**
 * asl_init - initialize the asynchronous schedule list
 *
 * A dummy qset with no qTDs is added to the ASL to simplify removing
 * qsets (no need to stop the ASL when the last qset is removed).
 */
int asl_init(struct whc *whc)
{
	struct whc_qset *qset;

	qset = qset_alloc(whc, GFP_KERNEL);
	if (qset == NULL)
		return -ENOMEM;

	asl_qset_insert_begin(whc, qset);
	asl_qset_insert(whc, qset);

	return 0;
}

/**
 * asl_clean_up - free ASL resources
 *
 * The ASL is stopped and empty except for the dummy qset.
 */
void asl_clean_up(struct whc *whc)
{
	struct whc_qset *qset;

	if (!list_empty(&whc->async_list)) {
		qset = list_first_entry(&whc->async_list, struct whc_qset, list_node);
		list_del(&qset->list_node);
		qset_free(whc, qset);
	}
}