1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * WUSB Wire Adapter: Control/Data Streaming Interface (WUSB[8])
4 * MMC (Microscheduled Management Command) handling
5 *
6 * Copyright (C) 2005-2006 Intel Corporation
7 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
8 *
9 * WUIEs and MMC IEs...well, they are almost the same at the end. MMC
10 * IEs are Wireless USB IEs that go into the MMC period...[what is
11 * that? look in Design-overview.txt].
12 *
13 *
14 * This is a simple subsystem to keep track of which IEs are being
15 * sent by the host in the MMC period.
16 *
17 * For each WUIE we ask to send, we keep it in an array, so we can
18 * request its removal later, or replace the content. They are tracked
19 * by pointer, so be sure to use the same pointer if you want to
20 * remove it or update the contents.
21 *
22 * FIXME:
23 * - add timers that autoremove intervalled IEs?
24 */
25 #include <linux/usb/wusb.h>
26 #include <linux/slab.h>
27 #include <linux/export.h>
28 #include "wusbhc.h"
29
30 /* Initialize the MMCIEs handling mechanism */
wusbhc_mmcie_create(struct wusbhc * wusbhc)31 int wusbhc_mmcie_create(struct wusbhc *wusbhc)
32 {
33 u8 mmcies = wusbhc->mmcies_max;
34 wusbhc->mmcie = kcalloc(mmcies, sizeof(wusbhc->mmcie[0]), GFP_KERNEL);
35 if (wusbhc->mmcie == NULL)
36 return -ENOMEM;
37 mutex_init(&wusbhc->mmcie_mutex);
38 return 0;
39 }
40
41 /* Release resources used by the MMCIEs handling mechanism */
wusbhc_mmcie_destroy(struct wusbhc * wusbhc)42 void wusbhc_mmcie_destroy(struct wusbhc *wusbhc)
43 {
44 kfree(wusbhc->mmcie);
45 }
46
47 /*
48 * Add or replace an MMC Wireless USB IE.
49 *
50 * @interval: See WUSB1.0[8.5.3.1]
51 * @repeat_cnt: See WUSB1.0[8.5.3.1]
52 * @handle: See WUSB1.0[8.5.3.1]
53 * @wuie: Pointer to the header of the WUSB IE data to add.
54 * MUST BE allocated in a kmalloc buffer (no stack or
55 * vmalloc).
56 * THE CALLER ALWAYS OWNS THE POINTER (we don't free it
57 * on remove, we just forget about it).
58 * @returns: 0 if ok, < 0 errno code on error.
59 *
60 * Goes over the *whole* @wusbhc->mmcie array looking for (a) the
61 * first free spot and (b) if @wuie is already in the array (aka:
62 * transmitted in the MMCs) the spot were it is.
63 *
64 * If present, we "overwrite it" (update).
65 *
66 *
67 * NOTE: Need special ordering rules -- see below WUSB1.0 Table 7-38.
68 * The host uses the handle as the 'sort' index. We
69 * allocate the last one always for the WUIE_ID_HOST_INFO, and
70 * the rest, first come first serve in inverse order.
71 *
72 * Host software must make sure that it adds the other IEs in
73 * the right order... the host hardware is responsible for
74 * placing the WCTA IEs in the right place with the other IEs
75 * set by host software.
76 *
77 * NOTE: we can access wusbhc->wa_descr without locking because it is
78 * read only.
79 */
wusbhc_mmcie_set(struct wusbhc * wusbhc,u8 interval,u8 repeat_cnt,struct wuie_hdr * wuie)80 int wusbhc_mmcie_set(struct wusbhc *wusbhc, u8 interval, u8 repeat_cnt,
81 struct wuie_hdr *wuie)
82 {
83 int result = -ENOBUFS;
84 unsigned handle, itr;
85
86 /* Search a handle, taking into account the ordering */
87 mutex_lock(&wusbhc->mmcie_mutex);
88 switch (wuie->bIEIdentifier) {
89 case WUIE_ID_HOST_INFO:
90 /* Always last */
91 handle = wusbhc->mmcies_max - 1;
92 break;
93 case WUIE_ID_ISOCH_DISCARD:
94 dev_err(wusbhc->dev, "Special ordering case for WUIE ID 0x%x "
95 "unimplemented\n", wuie->bIEIdentifier);
96 result = -ENOSYS;
97 goto error_unlock;
98 default:
99 /* search for it or find the last empty slot */
100 handle = ~0;
101 for (itr = 0; itr < wusbhc->mmcies_max - 1; itr++) {
102 if (wusbhc->mmcie[itr] == wuie) {
103 handle = itr;
104 break;
105 }
106 if (wusbhc->mmcie[itr] == NULL)
107 handle = itr;
108 }
109 if (handle == ~0)
110 goto error_unlock;
111 }
112 result = (wusbhc->mmcie_add)(wusbhc, interval, repeat_cnt, handle,
113 wuie);
114 if (result >= 0)
115 wusbhc->mmcie[handle] = wuie;
116 error_unlock:
117 mutex_unlock(&wusbhc->mmcie_mutex);
118 return result;
119 }
120 EXPORT_SYMBOL_GPL(wusbhc_mmcie_set);
121
122 /*
123 * Remove an MMC IE previously added with wusbhc_mmcie_set()
124 *
125 * @wuie Pointer used to add the WUIE
126 */
wusbhc_mmcie_rm(struct wusbhc * wusbhc,struct wuie_hdr * wuie)127 void wusbhc_mmcie_rm(struct wusbhc *wusbhc, struct wuie_hdr *wuie)
128 {
129 int result;
130 unsigned handle, itr;
131
132 mutex_lock(&wusbhc->mmcie_mutex);
133 for (itr = 0; itr < wusbhc->mmcies_max; itr++) {
134 if (wusbhc->mmcie[itr] == wuie) {
135 handle = itr;
136 goto found;
137 }
138 }
139 mutex_unlock(&wusbhc->mmcie_mutex);
140 return;
141
142 found:
143 result = (wusbhc->mmcie_rm)(wusbhc, handle);
144 if (result == 0)
145 wusbhc->mmcie[itr] = NULL;
146 mutex_unlock(&wusbhc->mmcie_mutex);
147 }
148 EXPORT_SYMBOL_GPL(wusbhc_mmcie_rm);
149
wusbhc_mmc_start(struct wusbhc * wusbhc)150 static int wusbhc_mmc_start(struct wusbhc *wusbhc)
151 {
152 int ret;
153
154 mutex_lock(&wusbhc->mutex);
155 ret = wusbhc->start(wusbhc);
156 if (ret >= 0)
157 wusbhc->active = 1;
158 mutex_unlock(&wusbhc->mutex);
159
160 return ret;
161 }
162
wusbhc_mmc_stop(struct wusbhc * wusbhc)163 static void wusbhc_mmc_stop(struct wusbhc *wusbhc)
164 {
165 mutex_lock(&wusbhc->mutex);
166 wusbhc->active = 0;
167 wusbhc->stop(wusbhc, WUSB_CHANNEL_STOP_DELAY_MS);
168 mutex_unlock(&wusbhc->mutex);
169 }
170
171 /*
172 * wusbhc_start - start transmitting MMCs and accepting connections
173 * @wusbhc: the HC to start
174 *
175 * Establishes a cluster reservation, enables device connections, and
176 * starts MMCs with appropriate DNTS parameters.
177 */
wusbhc_start(struct wusbhc * wusbhc)178 int wusbhc_start(struct wusbhc *wusbhc)
179 {
180 int result;
181 struct device *dev = wusbhc->dev;
182
183 WARN_ON(wusbhc->wuie_host_info != NULL);
184 BUG_ON(wusbhc->uwb_rc == NULL);
185
186 result = wusbhc_rsv_establish(wusbhc);
187 if (result < 0) {
188 dev_err(dev, "cannot establish cluster reservation: %d\n",
189 result);
190 goto error_rsv_establish;
191 }
192
193 result = wusbhc_devconnect_start(wusbhc);
194 if (result < 0) {
195 dev_err(dev, "error enabling device connections: %d\n",
196 result);
197 goto error_devconnect_start;
198 }
199
200 result = wusbhc_sec_start(wusbhc);
201 if (result < 0) {
202 dev_err(dev, "error starting security in the HC: %d\n",
203 result);
204 goto error_sec_start;
205 }
206
207 result = wusbhc->set_num_dnts(wusbhc, wusbhc->dnts_interval,
208 wusbhc->dnts_num_slots);
209 if (result < 0) {
210 dev_err(dev, "Cannot set DNTS parameters: %d\n", result);
211 goto error_set_num_dnts;
212 }
213 result = wusbhc_mmc_start(wusbhc);
214 if (result < 0) {
215 dev_err(dev, "error starting wusbch: %d\n", result);
216 goto error_wusbhc_start;
217 }
218
219 return 0;
220
221 error_wusbhc_start:
222 wusbhc_sec_stop(wusbhc);
223 error_set_num_dnts:
224 error_sec_start:
225 wusbhc_devconnect_stop(wusbhc);
226 error_devconnect_start:
227 wusbhc_rsv_terminate(wusbhc);
228 error_rsv_establish:
229 return result;
230 }
231
232 /*
233 * wusbhc_stop - stop transmitting MMCs
234 * @wusbhc: the HC to stop
235 *
236 * Stops the WUSB channel and removes the cluster reservation.
237 */
wusbhc_stop(struct wusbhc * wusbhc)238 void wusbhc_stop(struct wusbhc *wusbhc)
239 {
240 wusbhc_mmc_stop(wusbhc);
241 wusbhc_sec_stop(wusbhc);
242 wusbhc_devconnect_stop(wusbhc);
243 wusbhc_rsv_terminate(wusbhc);
244 }
245
246 /*
247 * Set/reset/update a new CHID
248 *
249 * Depending on the previous state of the MMCs, start, stop or change
250 * the sent MMC. This effectively switches the host controller on and
251 * off (radio wise).
252 */
wusbhc_chid_set(struct wusbhc * wusbhc,const struct wusb_ckhdid * chid)253 int wusbhc_chid_set(struct wusbhc *wusbhc, const struct wusb_ckhdid *chid)
254 {
255 int result = 0;
256
257 if (memcmp(chid, &wusb_ckhdid_zero, sizeof(*chid)) == 0)
258 chid = NULL;
259
260 mutex_lock(&wusbhc->mutex);
261 if (chid) {
262 if (wusbhc->active) {
263 mutex_unlock(&wusbhc->mutex);
264 return -EBUSY;
265 }
266 wusbhc->chid = *chid;
267 }
268
269 /* register with UWB if we haven't already since we are about to start
270 the radio. */
271 if ((chid) && (wusbhc->uwb_rc == NULL)) {
272 wusbhc->uwb_rc = uwb_rc_get_by_grandpa(wusbhc->dev->parent);
273 if (wusbhc->uwb_rc == NULL) {
274 result = -ENODEV;
275 dev_err(wusbhc->dev,
276 "Cannot get associated UWB Host Controller\n");
277 goto error_rc_get;
278 }
279
280 result = wusbhc_pal_register(wusbhc);
281 if (result < 0) {
282 dev_err(wusbhc->dev, "Cannot register as a UWB PAL\n");
283 goto error_pal_register;
284 }
285 }
286 mutex_unlock(&wusbhc->mutex);
287
288 if (chid)
289 result = uwb_radio_start(&wusbhc->pal);
290 else if (wusbhc->uwb_rc)
291 uwb_radio_stop(&wusbhc->pal);
292
293 return result;
294
295 error_pal_register:
296 uwb_rc_put(wusbhc->uwb_rc);
297 wusbhc->uwb_rc = NULL;
298 error_rc_get:
299 mutex_unlock(&wusbhc->mutex);
300
301 return result;
302 }
303 EXPORT_SYMBOL_GPL(wusbhc_chid_set);
304
