1/*
2 * UWB DRP IE management.
3 *
4 * Copyright (C) 2005-2006 Intel Corporation
5 * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
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 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19#include <linux/kernel.h>
20#include <linux/random.h>
21#include <linux/slab.h>
22#include <linux/uwb.h>
23
24#include "uwb-internal.h"
25
26
27/*
28 * Return the reason code for a reservations's DRP IE.
29 */
30static int uwb_rsv_reason_code(struct uwb_rsv *rsv)
31{
32 static const int reason_codes[] = {
33 [UWB_RSV_STATE_O_INITIATED] = UWB_DRP_REASON_ACCEPTED,
34 [UWB_RSV_STATE_O_PENDING] = UWB_DRP_REASON_ACCEPTED,
35 [UWB_RSV_STATE_O_MODIFIED] = UWB_DRP_REASON_MODIFIED,
36 [UWB_RSV_STATE_O_ESTABLISHED] = UWB_DRP_REASON_ACCEPTED,
37 [UWB_RSV_STATE_O_TO_BE_MOVED] = UWB_DRP_REASON_ACCEPTED,
38 [UWB_RSV_STATE_O_MOVE_COMBINING] = UWB_DRP_REASON_MODIFIED,
39 [UWB_RSV_STATE_O_MOVE_REDUCING] = UWB_DRP_REASON_MODIFIED,
40 [UWB_RSV_STATE_O_MOVE_EXPANDING] = UWB_DRP_REASON_ACCEPTED,
41 [UWB_RSV_STATE_T_ACCEPTED] = UWB_DRP_REASON_ACCEPTED,
42 [UWB_RSV_STATE_T_CONFLICT] = UWB_DRP_REASON_CONFLICT,
43 [UWB_RSV_STATE_T_PENDING] = UWB_DRP_REASON_PENDING,
44 [UWB_RSV_STATE_T_DENIED] = UWB_DRP_REASON_DENIED,
45 [UWB_RSV_STATE_T_RESIZED] = UWB_DRP_REASON_ACCEPTED,
46 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = UWB_DRP_REASON_ACCEPTED,
47 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = UWB_DRP_REASON_CONFLICT,
48 [UWB_RSV_STATE_T_EXPANDING_PENDING] = UWB_DRP_REASON_PENDING,
49 [UWB_RSV_STATE_T_EXPANDING_DENIED] = UWB_DRP_REASON_DENIED,
50 };
51
52 return reason_codes[rsv->state];
53}
54
55/*
56 * Return the reason code for a reservations's companion DRP IE .
57 */
58static int uwb_rsv_companion_reason_code(struct uwb_rsv *rsv)
59{
60 static const int companion_reason_codes[] = {
61 [UWB_RSV_STATE_O_MOVE_EXPANDING] = UWB_DRP_REASON_ACCEPTED,
62 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = UWB_DRP_REASON_ACCEPTED,
63 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = UWB_DRP_REASON_CONFLICT,
64 [UWB_RSV_STATE_T_EXPANDING_PENDING] = UWB_DRP_REASON_PENDING,
65 [UWB_RSV_STATE_T_EXPANDING_DENIED] = UWB_DRP_REASON_DENIED,
66 };
67
68 return companion_reason_codes[rsv->state];
69}
70
71/*
72 * Return the status bit for a reservations's DRP IE.
73 */
74int uwb_rsv_status(struct uwb_rsv *rsv)
75{
76 static const int statuses[] = {
77 [UWB_RSV_STATE_O_INITIATED] = 0,
78 [UWB_RSV_STATE_O_PENDING] = 0,
79 [UWB_RSV_STATE_O_MODIFIED] = 1,
80 [UWB_RSV_STATE_O_ESTABLISHED] = 1,
81 [UWB_RSV_STATE_O_TO_BE_MOVED] = 0,
82 [UWB_RSV_STATE_O_MOVE_COMBINING] = 1,
83 [UWB_RSV_STATE_O_MOVE_REDUCING] = 1,
84 [UWB_RSV_STATE_O_MOVE_EXPANDING] = 1,
85 [UWB_RSV_STATE_T_ACCEPTED] = 1,
86 [UWB_RSV_STATE_T_CONFLICT] = 0,
87 [UWB_RSV_STATE_T_PENDING] = 0,
88 [UWB_RSV_STATE_T_DENIED] = 0,
89 [UWB_RSV_STATE_T_RESIZED] = 1,
90 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = 1,
91 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = 1,
92 [UWB_RSV_STATE_T_EXPANDING_PENDING] = 1,
93 [UWB_RSV_STATE_T_EXPANDING_DENIED] = 1,
94
95 };
96
97 return statuses[rsv->state];
98}
99
100/*
101 * Return the status bit for a reservations's companion DRP IE .
102 */
103int uwb_rsv_companion_status(struct uwb_rsv *rsv)
104{
105 static const int companion_statuses[] = {
106 [UWB_RSV_STATE_O_MOVE_EXPANDING] = 0,
107 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = 1,
108 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = 0,
109 [UWB_RSV_STATE_T_EXPANDING_PENDING] = 0,
110 [UWB_RSV_STATE_T_EXPANDING_DENIED] = 0,
111 };
112
113 return companion_statuses[rsv->state];
114}
115
116/*
117 * Allocate a DRP IE.
118 *
119 * To save having to free/allocate a DRP IE when its MAS changes,
120 * enough memory is allocated for the maxiumum number of DRP
121 * allocation fields. This gives an overhead per reservation of up to
122 * (UWB_NUM_ZONES - 1) * 4 = 60 octets.
123 */
124static struct uwb_ie_drp *uwb_drp_ie_alloc(void)
125{
126 struct uwb_ie_drp *drp_ie;
127
128 drp_ie = kzalloc(struct_size(drp_ie, allocs, UWB_NUM_ZONES),
129 GFP_KERNEL);
130 if (drp_ie)
131 drp_ie->hdr.element_id = UWB_IE_DRP;
132 return drp_ie;
133}
134
135
136/*
137 * Fill a DRP IE's allocation fields from a MAS bitmap.
138 */
139static void uwb_drp_ie_from_bm(struct uwb_ie_drp *drp_ie,
140 struct uwb_mas_bm *mas)
141{
142 int z, i, num_fields = 0, next = 0;
143 struct uwb_drp_alloc *zones;
144 __le16 current_bmp;
145 DECLARE_BITMAP(tmp_bmp, UWB_NUM_MAS);
146 DECLARE_BITMAP(tmp_mas_bm, UWB_MAS_PER_ZONE);
147
148 zones = drp_ie->allocs;
149
150 bitmap_copy(tmp_bmp, mas->bm, UWB_NUM_MAS);
151
152 /* Determine unique MAS bitmaps in zones from bitmap. */
153 for (z = 0; z < UWB_NUM_ZONES; z++) {
154 bitmap_copy(tmp_mas_bm, tmp_bmp, UWB_MAS_PER_ZONE);
155 if (bitmap_weight(tmp_mas_bm, UWB_MAS_PER_ZONE) > 0) {
156 bool found = false;
157 current_bmp = (__le16) *tmp_mas_bm;
158 for (i = 0; i < next; i++) {
159 if (current_bmp == zones[i].mas_bm) {
160 zones[i].zone_bm |= 1 << z;
161 found = true;
162 break;
163 }
164 }
165 if (!found) {
166 num_fields++;
167 zones[next].zone_bm = 1 << z;
168 zones[next].mas_bm = current_bmp;
169 next++;
170 }
171 }
172 bitmap_shift_right(tmp_bmp, tmp_bmp, UWB_MAS_PER_ZONE, UWB_NUM_MAS);
173 }
174
175 /* Store in format ready for transmission (le16). */
176 for (i = 0; i < num_fields; i++) {
177 drp_ie->allocs[i].zone_bm = cpu_to_le16(zones[i].zone_bm);
178 drp_ie->allocs[i].mas_bm = cpu_to_le16(zones[i].mas_bm);
179 }
180
181 drp_ie->hdr.length = sizeof(struct uwb_ie_drp) - sizeof(struct uwb_ie_hdr)
182 + num_fields * sizeof(struct uwb_drp_alloc);
183}
184
185/**
186 * uwb_drp_ie_update - update a reservation's DRP IE
187 * @rsv: the reservation
188 */
189int uwb_drp_ie_update(struct uwb_rsv *rsv)
190{
191 struct uwb_ie_drp *drp_ie;
192 struct uwb_rsv_move *mv;
193 int unsafe;
194
195 if (rsv->state == UWB_RSV_STATE_NONE) {
196 kfree(rsv->drp_ie);
197 rsv->drp_ie = NULL;
198 return 0;
199 }
200
201 unsafe = rsv->mas.unsafe ? 1 : 0;
202
203 if (rsv->drp_ie == NULL) {
204 rsv->drp_ie = uwb_drp_ie_alloc();
205 if (rsv->drp_ie == NULL)
206 return -ENOMEM;
207 }
208 drp_ie = rsv->drp_ie;
209
210 uwb_ie_drp_set_unsafe(drp_ie, unsafe);
211 uwb_ie_drp_set_tiebreaker(drp_ie, rsv->tiebreaker);
212 uwb_ie_drp_set_owner(drp_ie, uwb_rsv_is_owner(rsv));
213 uwb_ie_drp_set_status(drp_ie, uwb_rsv_status(rsv));
214 uwb_ie_drp_set_reason_code(drp_ie, uwb_rsv_reason_code(rsv));
215 uwb_ie_drp_set_stream_index(drp_ie, rsv->stream);
216 uwb_ie_drp_set_type(drp_ie, rsv->type);
217
218 if (uwb_rsv_is_owner(rsv)) {
219 switch (rsv->target.type) {
220 case UWB_RSV_TARGET_DEV:
221 drp_ie->dev_addr = rsv->target.dev->dev_addr;
222 break;
223 case UWB_RSV_TARGET_DEVADDR:
224 drp_ie->dev_addr = rsv->target.devaddr;
225 break;
226 }
227 } else
228 drp_ie->dev_addr = rsv->owner->dev_addr;
229
230 uwb_drp_ie_from_bm(drp_ie, &rsv->mas);
231
232 if (uwb_rsv_has_two_drp_ies(rsv)) {
233 mv = &rsv->mv;
234 if (mv->companion_drp_ie == NULL) {
235 mv->companion_drp_ie = uwb_drp_ie_alloc();
236 if (mv->companion_drp_ie == NULL)
237 return -ENOMEM;
238 }
239 drp_ie = mv->companion_drp_ie;
240
241 /* keep all the same configuration of the main drp_ie */
242 memcpy(drp_ie, rsv->drp_ie, sizeof(struct uwb_ie_drp));
243
244
245 /* FIXME: handle properly the unsafe bit */
246 uwb_ie_drp_set_unsafe(drp_ie, 1);
247 uwb_ie_drp_set_status(drp_ie, uwb_rsv_companion_status(rsv));
248 uwb_ie_drp_set_reason_code(drp_ie, uwb_rsv_companion_reason_code(rsv));
249
250 uwb_drp_ie_from_bm(drp_ie, &mv->companion_mas);
251 }
252
253 rsv->ie_valid = true;
254 return 0;
255}
256
257/*
258 * Set MAS bits from given MAS bitmap in a single zone of large bitmap.
259 *
260 * We are given a zone id and the MAS bitmap of bits that need to be set in
261 * this zone. Note that this zone may already have bits set and this only
262 * adds settings - we cannot simply assign the MAS bitmap contents to the
263 * zone contents. We iterate over the the bits (MAS) in the zone and set the
264 * bits that are set in the given MAS bitmap.
265 */
266static
267void uwb_drp_ie_single_zone_to_bm(struct uwb_mas_bm *bm, u8 zone, u16 mas_bm)
268{
269 int mas;
270 u16 mas_mask;
271
272 for (mas = 0; mas < UWB_MAS_PER_ZONE; mas++) {
273 mas_mask = 1 << mas;
274 if (mas_bm & mas_mask)
275 set_bit(zone * UWB_NUM_ZONES + mas, bm->bm);
276 }
277}
278
279/**
280 * uwb_drp_ie_zones_to_bm - convert DRP allocation fields to a bitmap
281 * @mas: MAS bitmap that will be populated to correspond to the
282 * allocation fields in the DRP IE
283 * @drp_ie: the DRP IE that contains the allocation fields.
284 *
285 * The input format is an array of MAS allocation fields (16 bit Zone
286 * bitmap, 16 bit MAS bitmap) as described in [ECMA-368] section
287 * 16.8.6. The output is a full 256 bit MAS bitmap.
288 *
289 * We go over all the allocation fields, for each allocation field we
290 * know which zones are impacted. We iterate over all the zones
291 * impacted and call a function that will set the correct MAS bits in
292 * each zone.
293 */
294void uwb_drp_ie_to_bm(struct uwb_mas_bm *bm, const struct uwb_ie_drp *drp_ie)
295{
296 int numallocs = (drp_ie->hdr.length - 4) / 4;
297 const struct uwb_drp_alloc *alloc;
298 int cnt;
299 u16 zone_bm, mas_bm;
300 u8 zone;
301 u16 zone_mask;
302
303 bitmap_zero(bm->bm, UWB_NUM_MAS);
304
305 for (cnt = 0; cnt < numallocs; cnt++) {
306 alloc = &drp_ie->allocs[cnt];
307 zone_bm = le16_to_cpu(alloc->zone_bm);
308 mas_bm = le16_to_cpu(alloc->mas_bm);
309 for (zone = 0; zone < UWB_NUM_ZONES; zone++) {
310 zone_mask = 1 << zone;
311 if (zone_bm & zone_mask)
312 uwb_drp_ie_single_zone_to_bm(bm, zone, mas_bm);
313 }
314 }
315}
316
317