diff options
Diffstat (limited to 'src/osmo-bsc/acc.c')
| -rw-r--r-- | src/osmo-bsc/acc.c | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/src/osmo-bsc/acc.c b/src/osmo-bsc/acc.c new file mode 100644 index 000000000..a1941e42e --- /dev/null +++ b/src/osmo-bsc/acc.c @@ -0,0 +1,362 @@ +/* (C) 2018 by sysmocom s.f.m.c. GmbH <info@sysmocom.de> + * + * Author: Stefan Sperling <ssperling@sysmocom.de> + * + * All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation; either version 3 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 Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + */ + +#include <strings.h> +#include <errno.h> +#include <stdbool.h> + +#include <osmocom/bsc/debug.h> +#include <osmocom/bsc/acc.h> +#include <osmocom/bsc/gsm_data.h> +#include <osmocom/bsc/chan_alloc.h> +#include <osmocom/bsc/signal.h> +#include <osmocom/bsc/abis_nm.h> +#include <osmocom/bsc/bts.h> + +/* + * Check if an ACC has been permanently barred for a BTS, + * e.g. with the 'rach access-control-class' VTY command. + */ +static bool acc_is_permanently_barred(struct gsm_bts *bts, unsigned int acc) +{ + OSMO_ASSERT(acc <= 9); + if (acc == 8 || acc == 9) + return (bts->si_common.rach_control.t2 & (1 << (acc - 8))); + return (bts->si_common.rach_control.t3 & (1 << (acc))); +} + +static void allow_one_acc(struct acc_ramp *acc_ramp, unsigned int acc) +{ + OSMO_ASSERT(acc <= 9); + if (acc_ramp->barred_accs & (1 << acc)) + LOG_BTS(acc_ramp->bts, DRSL, LOGL_NOTICE, + "ACC RAMP: allowing Access Control Class %u\n", acc); + acc_ramp->barred_accs &= ~(1 << acc); +} + +static void barr_one_acc(struct acc_ramp *acc_ramp, unsigned int acc) +{ + OSMO_ASSERT(acc <= 9); + if ((acc_ramp->barred_accs & (1 << acc)) == 0) + LOG_BTS(acc_ramp->bts, DRSL, LOGL_NOTICE, + "ACC RAMP: barring Access Control Class %u\n", acc); + acc_ramp->barred_accs |= (1 << acc); +} + +static void barr_all_accs(struct acc_ramp *acc_ramp) +{ + unsigned int acc; + for (acc = 0; acc < 10; acc++) { + if (!acc_is_permanently_barred(acc_ramp->bts, acc)) + barr_one_acc(acc_ramp, acc); + } +} + +static void allow_all_accs(struct acc_ramp *acc_ramp) +{ + unsigned int acc; + for (acc = 0; acc < 10; acc++) { + if (!acc_is_permanently_barred(acc_ramp->bts, acc)) + allow_one_acc(acc_ramp, acc); + } +} + +static unsigned int get_next_step_interval(struct acc_ramp *acc_ramp) +{ + struct gsm_bts *bts = acc_ramp->bts; + uint64_t load; + + if (acc_ramp->step_interval_is_fixed) + return acc_ramp->step_interval_sec; + + /* Scale the step interval to current channel load average. */ + load = (bts->chan_load_avg << 8); /* convert to fixed-point */ + acc_ramp->step_interval_sec = ((load * ACC_RAMP_STEP_INTERVAL_MAX) / 100) >> 8; + if (acc_ramp->step_interval_sec < ACC_RAMP_STEP_SIZE_MIN) + acc_ramp->step_interval_sec = ACC_RAMP_STEP_INTERVAL_MIN; + else if (acc_ramp->step_interval_sec > ACC_RAMP_STEP_INTERVAL_MAX) + acc_ramp->step_interval_sec = ACC_RAMP_STEP_INTERVAL_MAX; + + LOG_BTS(bts, DRSL, LOGL_DEBUG, + "ACC RAMP: step interval set to %u seconds based on %u%% channel load average\n", + acc_ramp->step_interval_sec, bts->chan_load_avg); + return acc_ramp->step_interval_sec; +} + +static void do_acc_ramping_step(void *data) +{ + struct acc_ramp *acc_ramp = data; + int i; + + /* Shortcut in case we only do one ramping step. */ + if (acc_ramp->step_size == ACC_RAMP_STEP_SIZE_MAX) { + allow_all_accs(acc_ramp); + gsm_bts_set_system_infos(acc_ramp->bts); + return; + } + + /* Allow 'step_size' ACCs, starting from ACC0. ACC9 will be allowed last. */ + for (i = 0; i < acc_ramp->step_size; i++) { + int idx = ffs(acc_ramp_get_barred_t3(acc_ramp)); + if (idx > 0) { + /* One of ACC0-ACC7 is still bared. */ + unsigned int acc = idx - 1; + if (!acc_is_permanently_barred(acc_ramp->bts, acc)) + allow_one_acc(acc_ramp, acc); + } else { + idx = ffs(acc_ramp_get_barred_t2(acc_ramp)); + if (idx == 1 || idx == 2) { + /* ACC8 or ACC9 is still barred. */ + unsigned int acc = idx - 1 + 8; + if (!acc_is_permanently_barred(acc_ramp->bts, acc)) + allow_one_acc(acc_ramp, acc); + } else { + /* All ACCs are now allowed. */ + break; + } + } + } + + gsm_bts_set_system_infos(acc_ramp->bts); + + /* If we have not allowed all ACCs yet, schedule another ramping step. */ + if (acc_ramp_get_barred_t2(acc_ramp) != 0x00 || + acc_ramp_get_barred_t3(acc_ramp) != 0x00) + osmo_timer_schedule(&acc_ramp->step_timer, get_next_step_interval(acc_ramp), 0); +} + +/* Implements osmo_signal_cbfn() -- trigger or abort ACC ramping upon changes RF lock state. */ +static int acc_ramp_nm_sig_cb(unsigned int subsys, unsigned int signal, void *handler_data, void *signal_data) +{ + struct nm_statechg_signal_data *nsd = signal_data; + struct acc_ramp *acc_ramp = handler_data; + struct gsm_bts_trx *trx = NULL; + bool trigger_ramping = false, abort_ramping = false; + + /* Handled signals map to an Administrative State Change ACK, or a State Changed Event Report. */ + if (signal != S_NM_STATECHG_ADM && signal != S_NM_STATECHG_OPER) + return 0; + + if (nsd->obj_class != NM_OC_RADIO_CARRIER) + return 0; + + trx = nsd->obj; + + LOG_TRX(trx, DRSL, LOGL_DEBUG, "ACC RAMP: administrative state %s -> %s\n", + get_value_string(abis_nm_adm_state_names, nsd->old_state->administrative), + get_value_string(abis_nm_adm_state_names, nsd->new_state->administrative)); + LOG_TRX(trx, DRSL, LOGL_DEBUG, "ACC RAMP: operational state %s -> %s\n", + abis_nm_opstate_name(nsd->old_state->operational), + abis_nm_opstate_name(nsd->new_state->operational)); + + /* We only care about state changes of the first TRX. */ + if (trx->nr != 0) + return 0; + + /* RSL must already be up. We cannot send RACH system information to the BTS otherwise. */ + if (trx->rsl_link == NULL) { + LOG_TRX(trx, DRSL, LOGL_DEBUG, + "ACC RAMP: ignoring state change because RSL link is down\n"); + return 0; + } + + /* Trigger or abort ACC ramping based on the new state of this TRX. */ + if (nsd->old_state->administrative != nsd->new_state->administrative) { + switch (nsd->new_state->administrative) { + case NM_STATE_UNLOCKED: + if (nsd->old_state->operational != nsd->new_state->operational) { + /* + * Administrative and operational state have both changed. + * Trigger ramping only if TRX 0 will be both enabled and unlocked. + */ + if (nsd->new_state->operational == NM_OPSTATE_ENABLED) + trigger_ramping = true; + else + LOG_TRX(trx, DRSL, LOGL_DEBUG, + "ACC RAMP: ignoring state change because TRX is " + "transitioning into operational state '%s'\n", + abis_nm_opstate_name(nsd->new_state->operational)); + } else { + /* + * Operational state has not changed. + * Trigger ramping only if TRX 0 is already usable. + */ + if (trx_is_usable(trx)) + trigger_ramping = true; + else + LOG_TRX(trx, DRSL, LOGL_DEBUG, "ACC RAMP: ignoring state change " + "because TRX is not usable\n"); + } + break; + case NM_STATE_LOCKED: + case NM_STATE_SHUTDOWN: + abort_ramping = true; + break; + case NM_STATE_NULL: + default: + LOG_TRX(trx, DRSL, LOGL_ERROR, "ACC RAMP: unrecognized administrative state '0x%x' " + "reported for TRX 0\n", nsd->new_state->administrative); + break; + } + } + if (nsd->old_state->operational != nsd->new_state->operational) { + switch (nsd->new_state->operational) { + case NM_OPSTATE_ENABLED: + if (nsd->old_state->administrative != nsd->new_state->administrative) { + /* + * Administrative and operational state have both changed. + * Trigger ramping only if TRX 0 will be both enabled and unlocked. + */ + if (nsd->new_state->administrative == NM_STATE_UNLOCKED) + trigger_ramping = true; + else + LOG_TRX(trx, DRSL, LOGL_DEBUG, "ACC RAMP: ignoring state change " + "because TRX is transitioning into administrative state '%s'\n", + get_value_string(abis_nm_adm_state_names, nsd->new_state->administrative)); + } else { + /* + * Administrative state has not changed. + * Trigger ramping only if TRX 0 is already unlocked. + */ + if (trx->mo.nm_state.administrative == NM_STATE_UNLOCKED) + trigger_ramping = true; + else + LOG_TRX(trx, DRSL, LOGL_DEBUG, "ACC RAMP: ignoring state change " + "because TRX is in administrative state '%s'\n", + get_value_string(abis_nm_adm_state_names, trx->mo.nm_state.administrative)); + } + break; + case NM_OPSTATE_DISABLED: + abort_ramping = true; + break; + case NM_OPSTATE_NULL: + default: + LOG_TRX(trx, DRSL, LOGL_ERROR, "ACC RAMP: unrecognized operational state '0x%x' " + "reported for TRX 0\n", nsd->new_state->administrative); + break; + } + } + + if (trigger_ramping) + acc_ramp_trigger(acc_ramp); + else if (abort_ramping) + acc_ramp_abort(acc_ramp); + + return 0; +} + +/*! + * Initialize an acc_ramp data structure. + * Storage for this structure must be provided by the caller. + * + * By default, ACC ramping is disabled and all ACCs are allowed. + * + * \param[in] acc_ramp Pointer to acc_ramp structure to be initialized. + * \param[in] bts BTS which uses this ACC ramp data structure. + */ +void acc_ramp_init(struct acc_ramp *acc_ramp, struct gsm_bts *bts) +{ + acc_ramp->bts = bts; + acc_ramp_set_enabled(acc_ramp, false); + acc_ramp->step_size = ACC_RAMP_STEP_SIZE_DEFAULT; + acc_ramp->step_interval_sec = ACC_RAMP_STEP_INTERVAL_MIN; + acc_ramp->step_interval_is_fixed = false; + allow_all_accs(acc_ramp); + osmo_timer_setup(&acc_ramp->step_timer, do_acc_ramping_step, acc_ramp); + osmo_signal_register_handler(SS_NM, acc_ramp_nm_sig_cb, acc_ramp); +} + +/*! + * Change the ramping step size which controls how many ACCs will be allowed per ramping step. + * Returns negative on error (step_size out of range), else zero. + * \param[in] acc_ramp Pointer to acc_ramp structure. + * \param[in] step_size The new step size value. + */ +int acc_ramp_set_step_size(struct acc_ramp *acc_ramp, unsigned int step_size) +{ + if (step_size < ACC_RAMP_STEP_SIZE_MIN || step_size > ACC_RAMP_STEP_SIZE_MAX) + return -ERANGE; + + acc_ramp->step_size = step_size; + LOG_BTS(acc_ramp->bts, DRSL, LOGL_DEBUG, "ACC RAMP: ramping step size set to %u\n", step_size); + return 0; +} + +/*! + * Change the ramping step interval to a fixed value. Unless this function is called, + * the interval is automatically scaled to the BTS channel load average. + * \param[in] acc_ramp Pointer to acc_ramp structure. + * \param[in] step_interval The new fixed step interval in seconds. + */ +int acc_ramp_set_step_interval(struct acc_ramp *acc_ramp, unsigned int step_interval) +{ + if (step_interval < ACC_RAMP_STEP_INTERVAL_MIN || step_interval > ACC_RAMP_STEP_INTERVAL_MAX) + return -ERANGE; + + acc_ramp->step_interval_sec = step_interval; + acc_ramp->step_interval_is_fixed = true; + LOG_BTS(acc_ramp->bts, DRSL, LOGL_DEBUG, "ACC RAMP: ramping step interval set to %u seconds\n", + step_interval); + return 0; +} + +/*! + * Clear a previously set fixed ramping step interval, so that the interval + * is again automatically scaled to the BTS channel load average. + * \param[in] acc_ramp Pointer to acc_ramp structure. + */ +void acc_ramp_set_step_interval_dynamic(struct acc_ramp *acc_ramp) +{ + acc_ramp->step_interval_is_fixed = false; + LOG_BTS(acc_ramp->bts, DRSL, LOGL_DEBUG, "ACC RAMP: ramping step interval set to 'dynamic'\n"); +} + +/*! + * Determine if ACC ramping should be started according to configuration, and + * begin the ramping process if the necessary conditions are present. + * Perform at least one ramping step to allow 'step_size' ACCs. + * If 'step_size' is ACC_RAMP_STEP_SIZE_MAX, or if ACC ramping is disabled, + * all ACCs will be allowed immediately. + * \param[in] acc_ramp Pointer to acc_ramp structure. + */ +void acc_ramp_trigger(struct acc_ramp *acc_ramp) +{ + /* Abort any previously running ramping process and allow all available ACCs. */ + acc_ramp_abort(acc_ramp); + + if (acc_ramp_is_enabled(acc_ramp)) { + /* Set all available ACCs to barred and start ramping up. */ + barr_all_accs(acc_ramp); + do_acc_ramping_step(acc_ramp); + } +} + +/*! + * Abort the ramping process and allow all available ACCs immediately. + * \param[in] acc_ramp Pointer to acc_ramp structure. + */ +void acc_ramp_abort(struct acc_ramp *acc_ramp) +{ + if (osmo_timer_pending(&acc_ramp->step_timer)) + osmo_timer_del(&acc_ramp->step_timer); + + allow_all_accs(acc_ramp); +} |