/* (C) 2018 by sysmocom s.f.m.c. GmbH * * Author: Stefan Sperling * * 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 . * */ #include #include #include #include #include #include /* * 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_enabled(struct gsm_bts *bts, unsigned int acc) { OSMO_ASSERT(acc >= 0 && acc <= 9); if (acc == 8 || acc == 9) return (bts->si_common.rach_control.t2 & (1 << (acc - 8))) == 0; return (bts->si_common.rach_control.t3 & (1 << (acc))) == 0; } static void allow_one_acc(struct acc_ramp *acc_ramp, unsigned int acc) { OSMO_ASSERT(acc >= 0 && acc <= 9); LOGP(DRSL, LOGL_DEBUG, "(bts=%d) ACC RAMP: allowing Access Control Class %u\n", acc_ramp->bts->nr, acc); acc_ramp->barred_accs &= ~(1 << acc); } static void barr_one_acc(struct acc_ramp *acc_ramp, unsigned int acc) { OSMO_ASSERT(acc >= 0 && acc <= 9); LOGP(DRSL, LOGL_DEBUG, "(bts=%d) ACC RAMP: barring Access Control Class %u\n", acc_ramp->bts->nr, acc); acc_ramp->barred_accs |= (1 << acc); } static void barr_all_enabled_accs(struct acc_ramp *acc_ramp) { unsigned int acc; for (acc = 0; acc < 10; acc++) { if (acc_is_enabled(acc_ramp->bts, acc)) barr_one_acc(acc_ramp, acc); } } static void allow_all_enabled_accs(struct acc_ramp *acc_ramp) { unsigned int acc; for (acc = 0; acc < 10; acc++) { if (acc_is_enabled(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; LOGP(DRSL, LOGL_DEBUG, "(bts=%d) ACC RAMP: step interval set to %u seconds based on %u%% channel load average\n", bts->nr, 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_enabled_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_enabled(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_enabled(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); } /*! * Initialize an acc_ramp data structure. * Storage for this structure must be provided by the caller. * * If ACC ramping is enabled, all ACCs are denied by default. * A subsequent call to acc_ramp_start() will begin the ramping process. * If ACC ramping is disabled, all ACCs will be allowed by default, * and there is no need to do anything else. * * \param[in] acc_ramp Pointer to acc_ramp structure to be initialized. * \param[in] enable Indicates whether ACC ramping should be enabled or disabled. * \param[in] bts BTS which uses this ACC ramp data structure. */ void acc_ramp_init(struct acc_ramp *acc_ramp, bool enable, struct gsm_bts *bts) { acc_ramp->bts = bts; acc_ramp->acc_ramping_enabled = enable; 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; osmo_timer_setup(&acc_ramp->step_timer, do_acc_ramping_step, acc_ramp); if (acc_ramp->acc_ramping_enabled) barr_all_enabled_accs(acc_ramp); else allow_all_enabled_accs(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; LOGP(DRSL, LOGL_DEBUG, "(bts=%d) ACC RAMP: ramping step size set to %u\n", acc_ramp->bts->nr, 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; LOGP(DRSL, LOGL_DEBUG, "(bts=%d) ACC RAMP: ramping step interval set to %u seconds\n", acc_ramp->bts->nr, 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; LOGP(DRSL, LOGL_DEBUG, "(bts=%d) ACC RAMP: ramping step interval set to 'dynamic'\n", acc_ramp->bts->nr); } /*! * Begin the ramping process. Perform at least one ramping step to allow 'step_size' ACCs. * If 'step_size' is ACC_RAMP_STEP_SIZE_MAX, all ACCs will be allowed immediately. * \param[in] acc_ramp Pointer to acc_ramp structure. */ void acc_ramp_start(struct acc_ramp *acc_ramp) { /* Abort any previously running ramping process. */ acc_ramp_abort(acc_ramp); /* Set all availble ACCs to barred and start ramping up. */ barr_all_enabled_accs(acc_ramp); do_acc_ramping_step(acc_ramp); } /*! * Abort the ramping process. If ramping is disabled or has already finished, * then this function has no effect. * \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); }