aboutsummaryrefslogtreecommitdiffstats
path: root/src/gprs_rlcmac_sched.cpp
blob: 59e3d9d943071a20843a1c04122fcc053c98502f (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
368
369
370
371
372
373
374
375
376
377
378
379
/* PDCH scheduler
 *
 * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
 
#include <gprs_bssgp_pcu.h>
#include <gprs_rlcmac.h>
#include <pcu_l1_if.h>
#include <bts.h>
#include <tbf.h>

#include "pcu_utils.h"

#warning pass the parameters by struct???
static uint32_t sched_poll(BTS *bts,
		    uint8_t trx, uint8_t ts, uint32_t fn, uint8_t block_nr,
		    struct gprs_rlcmac_tbf **poll_tbf,
		    struct gprs_rlcmac_tbf **ul_ass_tbf,
		    struct gprs_rlcmac_tbf **dl_ass_tbf,
            struct gprs_rlcmac_ul_tbf **ul_ack_tbf,
            struct gprs_rlcmac_dl_tbf **dl_recon_tbf)
{
	struct gprs_rlcmac_ul_tbf *ul_tbf;
	struct gprs_rlcmac_dl_tbf *dl_tbf;
	LListHead<gprs_rlcmac_tbf> *pos;
	uint32_t poll_fn;

	/* check special TBF for events */
	poll_fn = fn + 4;
	if ((block_nr % 3) == 2)
		poll_fn ++;
	poll_fn = poll_fn % 2715648;
	llist_for_each(pos, &bts->ul_tbfs()) {
		ul_tbf = as_ul_tbf(pos->entry());
		OSMO_ASSERT(ul_tbf);
		/* this trx, this ts */
		if (ul_tbf->trx->trx_no != trx || !ul_tbf->is_control_ts(ts))
			continue;
		/* polling for next uplink block */
		if (ul_tbf->poll_state == GPRS_RLCMAC_POLL_SCHED
		 && ul_tbf->poll_fn == poll_fn)
			*poll_tbf = ul_tbf;
		if (ul_tbf->ul_ack_state == GPRS_RLCMAC_UL_ACK_SEND_ACK)
			*ul_ack_tbf = ul_tbf;
		if (ul_tbf->dl_ass_state == GPRS_RLCMAC_DL_ASS_SEND_ASS)
			*dl_ass_tbf = ul_tbf;
		if (ul_tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_SEND_ASS)
			*ul_ass_tbf = ul_tbf;
#warning "Is this supposed to be fair? The last TBF for each wins? Maybe use llist_add_tail and skip once we have all states?"
	}
	llist_for_each(pos, &bts->dl_tbfs()) {
		dl_tbf = as_dl_tbf(pos->entry());
		OSMO_ASSERT(dl_tbf);
		/* this trx, this ts */
		if (dl_tbf->trx->trx_no != trx || !dl_tbf->is_control_ts(ts))
			continue;
		/* polling for next uplink block */
		if (dl_tbf->poll_state == GPRS_RLCMAC_POLL_SCHED
		 && dl_tbf->poll_fn == poll_fn)
			*poll_tbf = dl_tbf;
		if (dl_tbf->dl_ass_state == GPRS_RLCMAC_DL_ASS_SEND_ASS)
			*dl_ass_tbf = dl_tbf;
		if (dl_tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_SEND_ASS)
			*ul_ass_tbf = dl_tbf;
		if (dl_tbf->needs_recon_to_be_scheduled()) {
		    *dl_recon_tbf = dl_tbf;
		    printf("PTSR! %s:%d\n", __func__, __LINE__);
		}
	}

	return poll_fn;
}

static uint8_t sched_select_uplink(uint8_t trx, uint8_t ts, uint32_t fn,
	uint8_t block_nr, struct gprs_rlcmac_pdch *pdch)
{
	struct gprs_rlcmac_ul_tbf *tbf;
	uint8_t usf = 0x07;
	uint8_t i, tfi;

	/* select uplink resource */
	for (i = 0, tfi = pdch->next_ul_tfi; i < 32;
	     i++, tfi = (tfi + 1) & 31) {
		tbf = pdch->ul_tbf_by_tfi(tfi);
		/* no TBF for this tfi, go next */
		if (!tbf)
			continue;
		/* no UL resources needed, go next */
		/* we don't need to give resources in FINISHED state,
		 * because we have received all blocks and only poll
		 * for packet control ack. */
		if (tbf->state_is_not(GPRS_RLCMAC_FLOW))
			continue;

		/* use this USF */
		usf = tbf->m_usf[ts];
		LOGP(DRLCMACSCHED, LOGL_DEBUG, "Received RTS for PDCH: TRX=%d "
			"TS=%d FN=%d block_nr=%d scheduling USF=%d for "
			"required uplink resource of UL TFI=%d\n", trx, ts, fn,
			block_nr, usf, tfi);
		/* next TBF to handle resource is the next one */
		pdch->next_ul_tfi = (tfi + 1) & 31;
		break;
	}

	return usf;
}

static struct msgb *sched_select_ctrl_msg(
		    uint8_t trx, uint8_t ts, uint32_t fn,
		    uint8_t block_nr, struct gprs_rlcmac_pdch *pdch,
		    struct gprs_rlcmac_tbf *ul_ass_tbf,
		    struct gprs_rlcmac_tbf *dl_ass_tbf,
            struct gprs_rlcmac_ul_tbf *ul_ack_tbf,
            struct gprs_rlcmac_dl_tbf *dl_recon_tbf)
{
	struct msgb *msg = NULL;
	struct gprs_rlcmac_tbf *tbf = NULL;
    struct gprs_rlcmac_tbf *next_list[] = { ul_ass_tbf, dl_ass_tbf, ul_ack_tbf, dl_recon_tbf };

	for (size_t i = 0; i < ARRAY_SIZE(next_list); ++i) {
		tbf = next_list[(pdch->next_ctrl_prio + i) % 4];
		if (!tbf)
			continue;

		/*
		 * Assignments for the same direction have lower precedence,
		 * because they may kill the TBF when the CONTOL ACK is
		 * received, thus preventing the others from being processed.
		 */

		if (tbf == ul_ass_tbf && tbf->direction == GPRS_RLCMAC_DL_TBF)
			msg = ul_ass_tbf->create_ul_ass(fn, ts);
		else if (tbf == dl_ass_tbf && tbf->direction == GPRS_RLCMAC_UL_TBF)
			msg = dl_ass_tbf->create_dl_ass(fn, ts);
		else if (tbf == ul_ack_tbf)
			msg = ul_ack_tbf->create_ul_ack(fn, ts);
		else if (tbf == dl_recon_tbf) {
		    msg = dl_recon_tbf->create_recon(fn, ts);
		    printf("PTSR! %s:%d %s\n", __func__, __LINE__, msgb_hexdump(msg));
		}
		if (!msg) {
			tbf = NULL;
			continue;
		}

		pdch->next_ctrl_prio += 1;
		pdch->next_ctrl_prio %= 4;
		break;
	}

	if (!msg) {
		/*
		 * If one of these is left, the response (CONTROL ACK) from the
		 * MS will kill the current TBF, only one of them can be
		 * non-NULL
		 */
		if (dl_ass_tbf) {
			tbf = dl_ass_tbf;
			msg = dl_ass_tbf->create_dl_ass(fn, ts);
		} else if (ul_ass_tbf) {
			tbf = ul_ass_tbf;
			msg = ul_ass_tbf->create_ul_ass(fn, ts);
		}
	}

	/* any message */
	if (msg) {
		tbf->rotate_in_list();
		LOGP(DRLCMACSCHED, LOGL_DEBUG, "Scheduling control "
			"message at RTS for %s (TRX=%d, TS=%d)\n",
			tbf_name(tbf), trx, ts);
		return msg;
	}
	/* schedule PACKET PAGING REQUEST */
	msg = pdch->packet_paging_request();
	if (msg) {
		LOGP(DRLCMACSCHED, LOGL_DEBUG, "Scheduling paging request "
			"message at RTS for (TRX=%d, TS=%d)\n", trx, ts);
		return msg;
	}

	return NULL;
}

static struct msgb *sched_select_downlink(struct gprs_rlcmac_bts *bts,
		    uint8_t trx, uint8_t ts, uint32_t fn,
		    uint8_t block_nr, struct gprs_rlcmac_pdch *pdch)
{
	struct msgb *msg = NULL;
	struct gprs_rlcmac_dl_tbf *tbf, *prio_tbf = NULL;
	enum {
		DL_PRIO_NONE,
		DL_PRIO_SENT_DATA, /* the data has been sent and not (yet) nacked */
		DL_PRIO_LOW_AGE,   /* the age has reached the first threshold */
		DL_PRIO_NEW_DATA,  /* the data has not been sent yet or nacked */
		DL_PRIO_HIGH_AGE,  /* the age has reached the second threshold */
		DL_PRIO_CONTROL,   /* a control block needs to be sent */
	} prio, max_prio = DL_PRIO_NONE;

	uint8_t i, tfi, prio_tfi;
	int age;
	const int age_thresh1 = msecs_to_frames(200);
	const int high_prio_msecs =
		OSMO_MIN(BTS::TIMER_T3190_MSEC/2, bts->dl_tbf_idle_msec);
	const int age_thresh2 = msecs_to_frames(high_prio_msecs);

	/* select downlink resource */
	for (i = 0, tfi = pdch->next_dl_tfi; i < 32;
	     i++, tfi = (tfi + 1) & 31) {
		tbf = pdch->dl_tbf_by_tfi(tfi);
		/* no TBF for this tfi, go next */
		if (!tbf)
			continue;
		/* no DL TBF, go next */
		if (tbf->direction != GPRS_RLCMAC_DL_TBF)
			continue;
		/* no DL resources needed, go next */
		if (tbf->state_is_not(GPRS_RLCMAC_FLOW)
		 && tbf->state_is_not(GPRS_RLCMAC_FINISHED))
			continue;

		/* waiting for CCCH IMM.ASS confirm */
		if (tbf->m_wait_confirm)
			continue;

		age = tbf->frames_since_last_poll(fn);

		/* compute priority */
		if (tbf->is_control_ts(ts) && tbf->need_control_ts())
			prio = DL_PRIO_CONTROL;
		else if (tbf->is_control_ts(ts) &&
			age > age_thresh2 && age_thresh2 > 0)
			prio = DL_PRIO_HIGH_AGE;
		else if ((tbf->state_is(GPRS_RLCMAC_FLOW) && tbf->have_data()) ||
			tbf->m_window.resend_needed() >= 0)
			prio = DL_PRIO_NEW_DATA;
		else if (tbf->is_control_ts(ts) &&
			age > age_thresh1 && tbf->keep_open(fn))
			prio = DL_PRIO_LOW_AGE;
		else if (!tbf->m_window.window_empty())
			prio = DL_PRIO_SENT_DATA;
		else
			continue;

		/* get the TBF with the highest priority */
		if (prio > max_prio) {
			prio_tfi = tfi;
			prio_tbf = tbf;
			max_prio = prio;
		}
	}

	if (prio_tbf) {
		LOGP(DRLCMACSCHED, LOGL_DEBUG, "Scheduling data message at "
			"RTS for DL TFI=%d (TRX=%d, TS=%d) prio=%d\n",
			prio_tfi, trx, ts, max_prio);
		/* next TBF to handle resource is the next one */
		pdch->next_dl_tfi = (prio_tfi + 1) & 31;
		/* generate DL data block */
		msg = prio_tbf->create_dl_acked_block(fn, ts);
	}

	return msg;
}

static const uint8_t rlcmac_dl_idle[23] = {
	0x47, /* control without optional header octets, no polling, USF=111 */
	0x94, /* dummy downlink control message, paging mode 00 */
	0x2b, /* no persistance level, 7 bits spare pattern */
	0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b,
	0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b
};

static struct msgb *sched_dummy(void)
{
	struct msgb *msg;

	msg = msgb_alloc(23, "rlcmac_dl_idle");
	if (!msg)
		return NULL;
	memcpy(msgb_put(msg, 23), rlcmac_dl_idle, 23);

	return msg;
}

int gprs_rlcmac_rcv_rts_block(struct gprs_rlcmac_bts *bts,
	uint8_t trx, uint8_t ts, uint16_t arfcn,
        uint32_t fn, uint8_t block_nr)
{
	struct gprs_rlcmac_pdch *pdch;
	struct gprs_rlcmac_tbf *poll_tbf = NULL, *dl_ass_tbf = NULL,
        *ul_ass_tbf = NULL;
	struct gprs_rlcmac_ul_tbf *ul_ack_tbf = NULL;
    struct gprs_rlcmac_dl_tbf *dl_recon_tbf = NULL;
	uint8_t usf = 0x7;
	struct msgb *msg = NULL;
	uint32_t poll_fn, sba_fn;

#warning "ARFCN... it is already in the TRX..... is it consistent with it?"

	if (trx >= 8 || ts >= 8)
		return -EINVAL;
	pdch = &bts->trx[trx].pdch[ts];

	if (!pdch->is_enabled()) {
		LOGP(DRLCMACSCHED, LOGL_ERROR, "Received RTS on disabled PDCH: "
			"TRX=%d TS=%d\n", trx, ts);
		return -EIO;
	}

	/* store last frame number of RTS */
	pdch->last_rts_fn = fn;

	poll_fn = sched_poll(bts->bts, trx, ts, fn, block_nr, &poll_tbf, &ul_ass_tbf,
        &dl_ass_tbf, &ul_ack_tbf, &dl_recon_tbf);
	/* check uplink resource for polling */
	if (poll_tbf){
	    printf("TBF=%s, FN=%d, POLL_FN=%d\n", tbf_name(poll_tbf), fn, poll_fn);
		LOGP(DRLCMACSCHED, LOGL_DEBUG, "Received RTS for PDCH: TRX=%d "
			"TS=%d FN=%d block_nr=%d scheduling free USF for "
			"polling at FN=%d of %s\n", trx, ts, fn,
			block_nr, poll_fn,
			tbf_name(poll_tbf));
	}
		/* use free USF */
	/* else. check for sba */
	else if ((sba_fn = bts->bts->sba()->sched(trx, ts, fn, block_nr) != 0xffffffff))
		LOGP(DRLCMACSCHED, LOGL_DEBUG, "Received RTS for PDCH: TRX=%d "
			"TS=%d FN=%d block_nr=%d scheduling free USF for "
			"single block allocation at FN=%d\n", trx, ts, fn,
			block_nr, sba_fn);
		/* use free USF */
	/* else, we search for uplink resource */
	else
		usf = sched_select_uplink(trx, ts, fn, block_nr, pdch);

	/* Prio 1: select control message */
	msg = sched_select_ctrl_msg(trx, ts, fn, block_nr, pdch, ul_ass_tbf,
        dl_ass_tbf, ul_ack_tbf, dl_recon_tbf);

	/* Prio 2: select data message for downlink */
	if (!msg)
		msg = sched_select_downlink(bts, trx, ts, fn, block_nr, pdch);

	/* Prio 3: send dummy contol message */
	if (!msg)
		msg = sched_dummy();

	if (!msg)
		return -ENOMEM;
	/* msg is now available */

	/* set USF */
	OSMO_ASSERT(msgb_length(msg) > 0);
	msg->data[0] = (msg->data[0] & 0xf8) | usf;

	/* Used to measure the leak rate, count all blocks */
	gprs_bssgp_update_frames_sent();

	/* send PDTCH/PACCH to L1 */
	pcu_l1if_tx_pdtch(msg, trx, ts, arfcn, fn, block_nr);

	return 0;
}