From 52409fae3e4b8d16b68b61902fc09075cd97b75d Mon Sep 17 00:00:00 2001 From: Dominik Sliwa Date: Sun, 2 Jul 2017 16:41:37 +0200 Subject: Backports generated from 4.11 kernel Initial commit. Signed-off-by: Dominik Sliwa --- drivers/net/wireless/ath/dfs_pri_detector.c | 437 ++++++++++++++++++++++++++++ 1 file changed, 437 insertions(+) create mode 100644 drivers/net/wireless/ath/dfs_pri_detector.c (limited to 'drivers/net/wireless/ath/dfs_pri_detector.c') diff --git a/drivers/net/wireless/ath/dfs_pri_detector.c b/drivers/net/wireless/ath/dfs_pri_detector.c new file mode 100644 index 0000000..05b0464 --- /dev/null +++ b/drivers/net/wireless/ath/dfs_pri_detector.c @@ -0,0 +1,437 @@ +/* + * Copyright (c) 2012 Neratec Solutions AG + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include +#include + +#include "ath.h" +#include "dfs_pattern_detector.h" +#include "dfs_pri_detector.h" + +struct ath_dfs_pool_stats global_dfs_pool_stats = {}; + +#define DFS_POOL_STAT_INC(c) (global_dfs_pool_stats.c++) +#define DFS_POOL_STAT_DEC(c) (global_dfs_pool_stats.c--) +#define GET_PRI_TO_USE(MIN, MAX, RUNTIME) \ + (MIN + PRI_TOLERANCE == MAX - PRI_TOLERANCE ? \ + MIN + PRI_TOLERANCE : RUNTIME) + +/** + * struct pulse_elem - elements in pulse queue + * @ts: time stamp in usecs + */ +struct pulse_elem { + struct list_head head; + u64 ts; +}; + +/** + * pde_get_multiple() - get number of multiples considering a given tolerance + * @return factor if abs(val - factor*fraction) <= tolerance, 0 otherwise + */ +static u32 pde_get_multiple(u32 val, u32 fraction, u32 tolerance) +{ + u32 remainder; + u32 factor; + u32 delta; + + if (fraction == 0) + return 0; + + delta = (val < fraction) ? (fraction - val) : (val - fraction); + + if (delta <= tolerance) + /* val and fraction are within tolerance */ + return 1; + + factor = val / fraction; + remainder = val % fraction; + if (remainder > tolerance) { + /* no exact match */ + if ((fraction - remainder) <= tolerance) + /* remainder is within tolerance */ + factor++; + else + factor = 0; + } + return factor; +} + +/** + * DOC: Singleton Pulse and Sequence Pools + * + * Instances of pri_sequence and pulse_elem are kept in singleton pools to + * reduce the number of dynamic allocations. They are shared between all + * instances and grow up to the peak number of simultaneously used objects. + * + * Memory is freed after all references to the pools are released. + */ +static u32 singleton_pool_references; +static LIST_HEAD(pulse_pool); +static LIST_HEAD(pseq_pool); +static DEFINE_SPINLOCK(pool_lock); + +static void pool_register_ref(void) +{ + spin_lock_bh(&pool_lock); + singleton_pool_references++; + DFS_POOL_STAT_INC(pool_reference); + spin_unlock_bh(&pool_lock); +} + +static void pool_deregister_ref(void) +{ + spin_lock_bh(&pool_lock); + singleton_pool_references--; + DFS_POOL_STAT_DEC(pool_reference); + if (singleton_pool_references == 0) { + /* free singleton pools with no references left */ + struct pri_sequence *ps, *ps0; + struct pulse_elem *p, *p0; + + list_for_each_entry_safe(p, p0, &pulse_pool, head) { + list_del(&p->head); + DFS_POOL_STAT_DEC(pulse_allocated); + kfree(p); + } + list_for_each_entry_safe(ps, ps0, &pseq_pool, head) { + list_del(&ps->head); + DFS_POOL_STAT_DEC(pseq_allocated); + kfree(ps); + } + } + spin_unlock_bh(&pool_lock); +} + +static void pool_put_pulse_elem(struct pulse_elem *pe) +{ + spin_lock_bh(&pool_lock); + list_add(&pe->head, &pulse_pool); + DFS_POOL_STAT_DEC(pulse_used); + spin_unlock_bh(&pool_lock); +} + +static void pool_put_pseq_elem(struct pri_sequence *pse) +{ + spin_lock_bh(&pool_lock); + list_add(&pse->head, &pseq_pool); + DFS_POOL_STAT_DEC(pseq_used); + spin_unlock_bh(&pool_lock); +} + +static struct pri_sequence *pool_get_pseq_elem(void) +{ + struct pri_sequence *pse = NULL; + spin_lock_bh(&pool_lock); + if (!list_empty(&pseq_pool)) { + pse = list_first_entry(&pseq_pool, struct pri_sequence, head); + list_del(&pse->head); + DFS_POOL_STAT_INC(pseq_used); + } + spin_unlock_bh(&pool_lock); + return pse; +} + +static struct pulse_elem *pool_get_pulse_elem(void) +{ + struct pulse_elem *pe = NULL; + spin_lock_bh(&pool_lock); + if (!list_empty(&pulse_pool)) { + pe = list_first_entry(&pulse_pool, struct pulse_elem, head); + list_del(&pe->head); + DFS_POOL_STAT_INC(pulse_used); + } + spin_unlock_bh(&pool_lock); + return pe; +} + +static struct pulse_elem *pulse_queue_get_tail(struct pri_detector *pde) +{ + struct list_head *l = &pde->pulses; + if (list_empty(l)) + return NULL; + return list_entry(l->prev, struct pulse_elem, head); +} + +static bool pulse_queue_dequeue(struct pri_detector *pde) +{ + struct pulse_elem *p = pulse_queue_get_tail(pde); + if (p != NULL) { + list_del_init(&p->head); + pde->count--; + /* give it back to pool */ + pool_put_pulse_elem(p); + } + return (pde->count > 0); +} + +/* remove pulses older than window */ +static void pulse_queue_check_window(struct pri_detector *pde) +{ + u64 min_valid_ts; + struct pulse_elem *p; + + /* there is no delta time with less than 2 pulses */ + if (pde->count < 2) + return; + + if (pde->last_ts <= pde->window_size) + return; + + min_valid_ts = pde->last_ts - pde->window_size; + while ((p = pulse_queue_get_tail(pde)) != NULL) { + if (p->ts >= min_valid_ts) + return; + pulse_queue_dequeue(pde); + } +} + +static bool pulse_queue_enqueue(struct pri_detector *pde, u64 ts) +{ + struct pulse_elem *p = pool_get_pulse_elem(); + if (p == NULL) { + p = kmalloc(sizeof(*p), GFP_ATOMIC); + if (p == NULL) { + DFS_POOL_STAT_INC(pulse_alloc_error); + return false; + } + DFS_POOL_STAT_INC(pulse_allocated); + DFS_POOL_STAT_INC(pulse_used); + } + INIT_LIST_HEAD(&p->head); + p->ts = ts; + list_add(&p->head, &pde->pulses); + pde->count++; + pde->last_ts = ts; + pulse_queue_check_window(pde); + if (pde->count >= pde->max_count) + pulse_queue_dequeue(pde); + return true; +} + +static bool pseq_handler_create_sequences(struct pri_detector *pde, + u64 ts, u32 min_count) +{ + struct pulse_elem *p; + list_for_each_entry(p, &pde->pulses, head) { + struct pri_sequence ps, *new_ps; + struct pulse_elem *p2; + u32 tmp_false_count; + u64 min_valid_ts; + u32 delta_ts = ts - p->ts; + + if (delta_ts < pde->rs->pri_min) + /* ignore too small pri */ + continue; + + if (delta_ts > pde->rs->pri_max) + /* stop on too large pri (sorted list) */ + break; + + /* build a new sequence with new potential pri */ + ps.count = 2; + ps.count_falses = 0; + ps.first_ts = p->ts; + ps.last_ts = ts; + ps.pri = GET_PRI_TO_USE(pde->rs->pri_min, + pde->rs->pri_max, ts - p->ts); + ps.dur = ps.pri * (pde->rs->ppb - 1) + + 2 * pde->rs->max_pri_tolerance; + + p2 = p; + tmp_false_count = 0; + min_valid_ts = ts - ps.dur; + /* check which past pulses are candidates for new sequence */ + list_for_each_entry_continue(p2, &pde->pulses, head) { + u32 factor; + if (p2->ts < min_valid_ts) + /* stop on crossing window border */ + break; + /* check if pulse match (multi)PRI */ + factor = pde_get_multiple(ps.last_ts - p2->ts, ps.pri, + pde->rs->max_pri_tolerance); + if (factor > 0) { + ps.count++; + ps.first_ts = p2->ts; + /* + * on match, add the intermediate falses + * and reset counter + */ + ps.count_falses += tmp_false_count; + tmp_false_count = 0; + } else { + /* this is a potential false one */ + tmp_false_count++; + } + } + if (ps.count <= min_count) + /* did not reach minimum count, drop sequence */ + continue; + + /* this is a valid one, add it */ + ps.deadline_ts = ps.first_ts + ps.dur; + new_ps = pool_get_pseq_elem(); + if (new_ps == NULL) { + new_ps = kmalloc(sizeof(*new_ps), GFP_ATOMIC); + if (new_ps == NULL) { + DFS_POOL_STAT_INC(pseq_alloc_error); + return false; + } + DFS_POOL_STAT_INC(pseq_allocated); + DFS_POOL_STAT_INC(pseq_used); + } + memcpy(new_ps, &ps, sizeof(ps)); + INIT_LIST_HEAD(&new_ps->head); + list_add(&new_ps->head, &pde->sequences); + } + return true; +} + +/* check new ts and add to all matching existing sequences */ +static u32 +pseq_handler_add_to_existing_seqs(struct pri_detector *pde, u64 ts) +{ + u32 max_count = 0; + struct pri_sequence *ps, *ps2; + list_for_each_entry_safe(ps, ps2, &pde->sequences, head) { + u32 delta_ts; + u32 factor; + + /* first ensure that sequence is within window */ + if (ts > ps->deadline_ts) { + list_del_init(&ps->head); + pool_put_pseq_elem(ps); + continue; + } + + delta_ts = ts - ps->last_ts; + factor = pde_get_multiple(delta_ts, ps->pri, + pde->rs->max_pri_tolerance); + if (factor > 0) { + ps->last_ts = ts; + ps->count++; + + if (max_count < ps->count) + max_count = ps->count; + } else { + ps->count_falses++; + } + } + return max_count; +} + +static struct pri_sequence * +pseq_handler_check_detection(struct pri_detector *pde) +{ + struct pri_sequence *ps; + + if (list_empty(&pde->sequences)) + return NULL; + + list_for_each_entry(ps, &pde->sequences, head) { + /* + * we assume to have enough matching confidence if we + * 1) have enough pulses + * 2) have more matching than false pulses + */ + if ((ps->count >= pde->rs->ppb_thresh) && + (ps->count * pde->rs->num_pri >= ps->count_falses)) + return ps; + } + return NULL; +} + + +/* free pulse queue and sequences list and give objects back to pools */ +static void pri_detector_reset(struct pri_detector *pde, u64 ts) +{ + struct pri_sequence *ps, *ps0; + struct pulse_elem *p, *p0; + list_for_each_entry_safe(ps, ps0, &pde->sequences, head) { + list_del_init(&ps->head); + pool_put_pseq_elem(ps); + } + list_for_each_entry_safe(p, p0, &pde->pulses, head) { + list_del_init(&p->head); + pool_put_pulse_elem(p); + } + pde->count = 0; + pde->last_ts = ts; +} + +static void pri_detector_exit(struct pri_detector *de) +{ + pri_detector_reset(de, 0); + pool_deregister_ref(); + kfree(de); +} + +static struct pri_sequence *pri_detector_add_pulse(struct pri_detector *de, + struct pulse_event *event) +{ + u32 max_updated_seq; + struct pri_sequence *ps; + u64 ts = event->ts; + const struct radar_detector_specs *rs = de->rs; + + /* ignore pulses not within width range */ + if ((rs->width_min > event->width) || (rs->width_max < event->width)) + return NULL; + + if ((ts - de->last_ts) < rs->max_pri_tolerance) + /* if delta to last pulse is too short, don't use this pulse */ + return NULL; + /* radar detector spec needs chirp, but not detected */ + if (rs->chirp && rs->chirp != event->chirp) + return NULL; + + de->last_ts = ts; + + max_updated_seq = pseq_handler_add_to_existing_seqs(de, ts); + + if (!pseq_handler_create_sequences(de, ts, max_updated_seq)) { + pri_detector_reset(de, ts); + return NULL; + } + + ps = pseq_handler_check_detection(de); + + if (ps == NULL) + pulse_queue_enqueue(de, ts); + + return ps; +} + +struct pri_detector *pri_detector_init(const struct radar_detector_specs *rs) +{ + struct pri_detector *de; + + de = kzalloc(sizeof(*de), GFP_ATOMIC); + if (de == NULL) + return NULL; + de->exit = pri_detector_exit; + de->add_pulse = pri_detector_add_pulse; + de->reset = pri_detector_reset; + + INIT_LIST_HEAD(&de->sequences); + INIT_LIST_HEAD(&de->pulses); + de->window_size = rs->pri_max * rs->ppb * rs->num_pri; + de->max_count = rs->ppb * 2; + de->rs = rs; + + pool_register_ref(); + return de; +} -- cgit v1.2.3