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tbf: Move the creation of a new tbf for the downlink to a new method 

Move the code that is dedicated to handle the assignment of a new
TFI/TBF for the downlink into a new method.
This commit is contained in:
Holger Hans Peter Freyther 2013-08-24 20:59:46 +02:00 committed by Ivan Kluchnikov
parent d868928888
commit 443c822f77
1 changed files with 80 additions and 70 deletions
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150
src/tbf.cpp
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@ -102,6 +102,81 @@ static int tbf_append_data(struct gprs_rlcmac_tbf *tbf,
return 0;
}
static int tbf_new_dl_assignment(struct gprs_rlcmac_bts *bts,
const char *imsi,
const uint32_t tlli, const uint8_t ms_class,
const uint8_t *data, const uint16_t len)
{
uint8_t trx, ta, ss;
int8_t use_trx;
struct gprs_rlcmac_tbf *old_tbf, *tbf;
int8_t tfi; /* must be signed */
int rc;
/* check for uplink data, so we copy our informations */
tbf = tbf_by_tlli(tlli, GPRS_RLCMAC_UL_TBF);
if (tbf && tbf->dir.ul.contention_resolution_done
&& !tbf->dir.ul.final_ack_sent) {
use_trx = tbf->trx;
ta = tbf->ta;
ss = 0;
old_tbf = tbf;
} else {
use_trx = -1;
/* we already have an uplink TBF, so we use that TA */
if (tbf)
ta = tbf->ta;
else {
/* recall TA */
rc = recall_timing_advance(tlli);
if (rc < 0) {
LOGP(DRLCMAC, LOGL_NOTICE, "TA unknown"
", assuming 0\n");
ta = 0;
} else
ta = rc;
}
ss = 1; /* PCH assignment only allows one timeslot */
old_tbf = NULL;
}
// Create new TBF (any TRX)
tfi = tfi_find_free(bts, GPRS_RLCMAC_DL_TBF, &trx, use_trx);
if (tfi < 0) {
LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n");
/* FIXME: send reject */
return -EBUSY;
}
/* set number of downlink slots according to multislot class */
tbf = tbf_alloc(bts, tbf, GPRS_RLCMAC_DL_TBF, tfi, trx, ms_class, ss);
if (!tbf) {
LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH ressource\n");
/* FIXME: send reject */
return -EBUSY;
}
tbf->tlli = tlli;
tbf->tlli_valid = 1;
tbf->ta = ta;
LOGP(DRLCMAC, LOGL_DEBUG,
"TBF: [DOWNLINK] START TFI: %d TLLI: 0x%08x \n",
tbf->tfi, tbf->tlli);
/* new TBF, so put first frame */
memcpy(tbf->llc_frame, data, len);
tbf->llc_length = len;
/* trigger downlink assignment and set state to ASSIGN.
* we don't use old_downlink, so the possible uplink is used
* to trigger downlink assignment. if there is no uplink,
* AGCH is used. */
gprs_rlcmac_trigger_downlink_assignment(tbf, old_tbf, imsi);
/* store IMSI for debugging purpose. TODO: it is more than debugging */
tbf_assign_imsi(tbf, imsi);
return 0;
}
/**
* TODO: split into unit test-able parts...
*/
@ -111,81 +186,16 @@ int tbf_handle(struct gprs_rlcmac_bts *bts,
const uint8_t *data, const uint16_t len)
{
struct gprs_rlcmac_tbf *tbf;
int8_t tfi; /* must be signed */
/* check for existing TBF */
tbf = tbf_lookup_dl(tlli, imsi);
if (tbf) {
int rc = tbf_append_data(tbf, bts, ms_class,
delay_csec, data, len);
if (rc < 0)
return rc;
} else {
uint8_t trx, ta, ss;
int8_t use_trx;
struct gprs_rlcmac_tbf *old_tbf;
int rc;
if (rc >= 0)
tbf_assign_imsi(tbf, imsi);
return rc;
}
/* check for uplink data, so we copy our informations */
tbf = tbf_by_tlli(tlli, GPRS_RLCMAC_UL_TBF);
if (tbf && tbf->dir.ul.contention_resolution_done
&& !tbf->dir.ul.final_ack_sent) {
use_trx = tbf->trx;
ta = tbf->ta;
ss = 0;
old_tbf = tbf;
} else {
use_trx = -1;
/* we already have an uplink TBF, so we use that TA */
if (tbf)
ta = tbf->ta;
else {
/* recall TA */
rc = recall_timing_advance(tlli);
if (rc < 0) {
LOGP(DRLCMAC, LOGL_NOTICE, "TA unknown"
", assuming 0\n");
ta = 0;
} else
ta = rc;
}
ss = 1; /* PCH assignment only allows one timeslot */
old_tbf = NULL;
}
// Create new TBF (any TRX)
tfi = tfi_find_free(bts, GPRS_RLCMAC_DL_TBF, &trx, use_trx);
if (tfi < 0) {
LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n");
/* FIXME: send reject */
return -EBUSY;
}
/* set number of downlink slots according to multislot class */
tbf = tbf_alloc(bts, tbf, GPRS_RLCMAC_DL_TBF, tfi, trx, ms_class,
ss);
if (!tbf) {
LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH ressource\n");
/* FIXME: send reject */
return -EBUSY;
}
tbf->tlli = tlli;
tbf->tlli_valid = 1;
tbf->ta = ta;
LOGP(DRLCMAC, LOGL_DEBUG, "TBF: [DOWNLINK] START TFI: %d TLLI: 0x%08x \n", tbf->tfi, tbf->tlli);
/* new TBF, so put first frame */
memcpy(tbf->llc_frame, data, len);
tbf->llc_length = len;
/* trigger downlink assignment and set state to ASSIGN.
* we don't use old_downlink, so the possible uplink is used
* to trigger downlink assignment. if there is no uplink,
* AGCH is used. */
gprs_rlcmac_trigger_downlink_assignment(tbf, old_tbf, imsi);
}
/* store IMSI for debugging purpose. TODO: it is more than debugging */
tbf_assign_imsi(tbf, imsi);
return 0;
return tbf_new_dl_assignment(bts, imsi, tlli, ms_class, data, len);
}