| /* (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_ramp.h> |
| #include <osmocom/bsc/gsm_data.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_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); |
| } |