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