diff options
Diffstat (limited to 'drivers/uwb/rsv.c')
| -rw-r--r-- | drivers/uwb/rsv.c | 1011 |
1 files changed, 1011 insertions, 0 deletions
diff --git a/drivers/uwb/rsv.c b/drivers/uwb/rsv.c new file mode 100644 index 000000000..fe25a8cc6 --- /dev/null +++ b/drivers/uwb/rsv.c @@ -0,0 +1,1011 @@ +/* + * UWB reservation management. + * + * Copyright (C) 2008 Cambridge Silicon Radio Ltd. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version + * 2 as published by the Free Software Foundation. + * + * 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#include <linux/kernel.h> +#include <linux/uwb.h> +#include <linux/slab.h> +#include <linux/random.h> +#include <linux/export.h> + +#include "uwb-internal.h" + +static void uwb_rsv_timer(struct timer_list *t); + +static const char *rsv_states[] = { + [UWB_RSV_STATE_NONE] = "none ", + [UWB_RSV_STATE_O_INITIATED] = "o initiated ", + [UWB_RSV_STATE_O_PENDING] = "o pending ", + [UWB_RSV_STATE_O_MODIFIED] = "o modified ", + [UWB_RSV_STATE_O_ESTABLISHED] = "o established ", + [UWB_RSV_STATE_O_TO_BE_MOVED] = "o to be moved ", + [UWB_RSV_STATE_O_MOVE_EXPANDING] = "o move expanding", + [UWB_RSV_STATE_O_MOVE_COMBINING] = "o move combining", + [UWB_RSV_STATE_O_MOVE_REDUCING] = "o move reducing ", + [UWB_RSV_STATE_T_ACCEPTED] = "t accepted ", + [UWB_RSV_STATE_T_CONFLICT] = "t conflict ", + [UWB_RSV_STATE_T_PENDING] = "t pending ", + [UWB_RSV_STATE_T_DENIED] = "t denied ", + [UWB_RSV_STATE_T_RESIZED] = "t resized ", + [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = "t expanding acc ", + [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = "t expanding conf", + [UWB_RSV_STATE_T_EXPANDING_PENDING] = "t expanding pend", + [UWB_RSV_STATE_T_EXPANDING_DENIED] = "t expanding den ", +}; + +static const char *rsv_types[] = { + [UWB_DRP_TYPE_ALIEN_BP] = "alien-bp", + [UWB_DRP_TYPE_HARD] = "hard", + [UWB_DRP_TYPE_SOFT] = "soft", + [UWB_DRP_TYPE_PRIVATE] = "private", + [UWB_DRP_TYPE_PCA] = "pca", +}; + +bool uwb_rsv_has_two_drp_ies(struct uwb_rsv *rsv) +{ + static const bool has_two_drp_ies[] = { + [UWB_RSV_STATE_O_INITIATED] = false, + [UWB_RSV_STATE_O_PENDING] = false, + [UWB_RSV_STATE_O_MODIFIED] = false, + [UWB_RSV_STATE_O_ESTABLISHED] = false, + [UWB_RSV_STATE_O_TO_BE_MOVED] = false, + [UWB_RSV_STATE_O_MOVE_COMBINING] = false, + [UWB_RSV_STATE_O_MOVE_REDUCING] = false, + [UWB_RSV_STATE_O_MOVE_EXPANDING] = true, + [UWB_RSV_STATE_T_ACCEPTED] = false, + [UWB_RSV_STATE_T_CONFLICT] = false, + [UWB_RSV_STATE_T_PENDING] = false, + [UWB_RSV_STATE_T_DENIED] = false, + [UWB_RSV_STATE_T_RESIZED] = false, + [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = true, + [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = true, + [UWB_RSV_STATE_T_EXPANDING_PENDING] = true, + [UWB_RSV_STATE_T_EXPANDING_DENIED] = true, + }; + + return has_two_drp_ies[rsv->state]; +} + +/** + * uwb_rsv_state_str - return a string for a reservation state + * @state: the reservation state. + */ +const char *uwb_rsv_state_str(enum uwb_rsv_state state) +{ + if (state < UWB_RSV_STATE_NONE || state >= UWB_RSV_STATE_LAST) + return "unknown"; + return rsv_states[state]; +} +EXPORT_SYMBOL_GPL(uwb_rsv_state_str); + +/** + * uwb_rsv_type_str - return a string for a reservation type + * @type: the reservation type + */ +const char *uwb_rsv_type_str(enum uwb_drp_type type) +{ + if (type < UWB_DRP_TYPE_ALIEN_BP || type > UWB_DRP_TYPE_PCA) + return "invalid"; + return rsv_types[type]; +} +EXPORT_SYMBOL_GPL(uwb_rsv_type_str); + +void uwb_rsv_dump(char *text, struct uwb_rsv *rsv) +{ + struct device *dev = &rsv->rc->uwb_dev.dev; + struct uwb_dev_addr devaddr; + char owner[UWB_ADDR_STRSIZE], target[UWB_ADDR_STRSIZE]; + + uwb_dev_addr_print(owner, sizeof(owner), &rsv->owner->dev_addr); + if (rsv->target.type == UWB_RSV_TARGET_DEV) + devaddr = rsv->target.dev->dev_addr; + else + devaddr = rsv->target.devaddr; + uwb_dev_addr_print(target, sizeof(target), &devaddr); + + dev_dbg(dev, "rsv %s %s -> %s: %s\n", + text, owner, target, uwb_rsv_state_str(rsv->state)); +} + +static void uwb_rsv_release(struct kref *kref) +{ + struct uwb_rsv *rsv = container_of(kref, struct uwb_rsv, kref); + + kfree(rsv); +} + +void uwb_rsv_get(struct uwb_rsv *rsv) +{ + kref_get(&rsv->kref); +} + +void uwb_rsv_put(struct uwb_rsv *rsv) +{ + kref_put(&rsv->kref, uwb_rsv_release); +} + +/* + * Get a free stream index for a reservation. + * + * If the target is a DevAddr (e.g., a WUSB cluster reservation) then + * the stream is allocated from a pool of per-RC stream indexes, + * otherwise a unique stream index for the target is selected. + */ +static int uwb_rsv_get_stream(struct uwb_rsv *rsv) +{ + struct uwb_rc *rc = rsv->rc; + struct device *dev = &rc->uwb_dev.dev; + unsigned long *streams_bm; + int stream; + + switch (rsv->target.type) { + case UWB_RSV_TARGET_DEV: + streams_bm = rsv->target.dev->streams; + break; + case UWB_RSV_TARGET_DEVADDR: + streams_bm = rc->uwb_dev.streams; + break; + default: + return -EINVAL; + } + + stream = find_first_zero_bit(streams_bm, UWB_NUM_STREAMS); + if (stream >= UWB_NUM_STREAMS) { + dev_err(dev, "%s: no available stream found\n", __func__); + return -EBUSY; + } + + rsv->stream = stream; + set_bit(stream, streams_bm); + + dev_dbg(dev, "get stream %d\n", rsv->stream); + + return 0; +} + +static void uwb_rsv_put_stream(struct uwb_rsv *rsv) +{ + struct uwb_rc *rc = rsv->rc; + struct device *dev = &rc->uwb_dev.dev; + unsigned long *streams_bm; + + switch (rsv->target.type) { + case UWB_RSV_TARGET_DEV: + streams_bm = rsv->target.dev->streams; + break; + case UWB_RSV_TARGET_DEVADDR: + streams_bm = rc->uwb_dev.streams; + break; + default: + return; + } + + clear_bit(rsv->stream, streams_bm); + + dev_dbg(dev, "put stream %d\n", rsv->stream); +} + +void uwb_rsv_backoff_win_timer(struct timer_list *t) +{ + struct uwb_drp_backoff_win *bow = from_timer(bow, t, timer); + struct uwb_rc *rc = container_of(bow, struct uwb_rc, bow); + struct device *dev = &rc->uwb_dev.dev; + + bow->can_reserve_extra_mases = true; + if (bow->total_expired <= 4) { + bow->total_expired++; + } else { + /* after 4 backoff window has expired we can exit from + * the backoff procedure */ + bow->total_expired = 0; + bow->window = UWB_DRP_BACKOFF_WIN_MIN >> 1; + } + dev_dbg(dev, "backoff_win_timer total_expired=%d, n=%d\n", bow->total_expired, bow->n); + + /* try to relocate all the "to be moved" relocations */ + uwb_rsv_handle_drp_avail_change(rc); +} + +void uwb_rsv_backoff_win_increment(struct uwb_rc *rc) +{ + struct uwb_drp_backoff_win *bow = &rc->bow; + struct device *dev = &rc->uwb_dev.dev; + unsigned timeout_us; + + dev_dbg(dev, "backoff_win_increment: window=%d\n", bow->window); + + bow->can_reserve_extra_mases = false; + + if((bow->window << 1) == UWB_DRP_BACKOFF_WIN_MAX) + return; + + bow->window <<= 1; + bow->n = prandom_u32() & (bow->window - 1); + dev_dbg(dev, "new_window=%d, n=%d\n", bow->window, bow->n); + + /* reset the timer associated variables */ + timeout_us = bow->n * UWB_SUPERFRAME_LENGTH_US; + bow->total_expired = 0; + mod_timer(&bow->timer, jiffies + usecs_to_jiffies(timeout_us)); +} + +static void uwb_rsv_stroke_timer(struct uwb_rsv *rsv) +{ + int sframes = UWB_MAX_LOST_BEACONS; + + /* + * Multicast reservations can become established within 1 + * super frame and should not be terminated if no response is + * received. + */ + if (rsv->state == UWB_RSV_STATE_NONE) { + sframes = 0; + } else if (rsv->is_multicast) { + if (rsv->state == UWB_RSV_STATE_O_INITIATED + || rsv->state == UWB_RSV_STATE_O_MOVE_EXPANDING + || rsv->state == UWB_RSV_STATE_O_MOVE_COMBINING + || rsv->state == UWB_RSV_STATE_O_MOVE_REDUCING) + sframes = 1; + if (rsv->state == UWB_RSV_STATE_O_ESTABLISHED) + sframes = 0; + + } + + if (sframes > 0) { + /* + * Add an additional 2 superframes to account for the + * time to send the SET DRP IE command. + */ + unsigned timeout_us = (sframes + 2) * UWB_SUPERFRAME_LENGTH_US; + mod_timer(&rsv->timer, jiffies + usecs_to_jiffies(timeout_us)); + } else + del_timer(&rsv->timer); +} + +/* + * Update a reservations state, and schedule an update of the + * transmitted DRP IEs. + */ +static void uwb_rsv_state_update(struct uwb_rsv *rsv, + enum uwb_rsv_state new_state) +{ + rsv->state = new_state; + rsv->ie_valid = false; + + uwb_rsv_dump("SU", rsv); + + uwb_rsv_stroke_timer(rsv); + uwb_rsv_sched_update(rsv->rc); +} + +static void uwb_rsv_callback(struct uwb_rsv *rsv) +{ + if (rsv->callback) + rsv->callback(rsv); +} + +void uwb_rsv_set_state(struct uwb_rsv *rsv, enum uwb_rsv_state new_state) +{ + struct uwb_rsv_move *mv = &rsv->mv; + + if (rsv->state == new_state) { + switch (rsv->state) { + case UWB_RSV_STATE_O_ESTABLISHED: + case UWB_RSV_STATE_O_MOVE_EXPANDING: + case UWB_RSV_STATE_O_MOVE_COMBINING: + case UWB_RSV_STATE_O_MOVE_REDUCING: + case UWB_RSV_STATE_T_ACCEPTED: + case UWB_RSV_STATE_T_EXPANDING_ACCEPTED: + case UWB_RSV_STATE_T_RESIZED: + case UWB_RSV_STATE_NONE: + uwb_rsv_stroke_timer(rsv); + break; + default: + /* Expecting a state transition so leave timer + as-is. */ + break; + } + return; + } + + uwb_rsv_dump("SC", rsv); + + switch (new_state) { + case UWB_RSV_STATE_NONE: + uwb_rsv_state_update(rsv, UWB_RSV_STATE_NONE); + uwb_rsv_remove(rsv); + uwb_rsv_callback(rsv); + break; + case UWB_RSV_STATE_O_INITIATED: + uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_INITIATED); + break; + case UWB_RSV_STATE_O_PENDING: + uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_PENDING); + break; + case UWB_RSV_STATE_O_MODIFIED: + /* in the companion there are the MASes to drop */ + bitmap_andnot(rsv->mas.bm, rsv->mas.bm, mv->companion_mas.bm, UWB_NUM_MAS); + uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MODIFIED); + break; + case UWB_RSV_STATE_O_ESTABLISHED: + if (rsv->state == UWB_RSV_STATE_O_MODIFIED + || rsv->state == UWB_RSV_STATE_O_MOVE_REDUCING) { + uwb_drp_avail_release(rsv->rc, &mv->companion_mas); + rsv->needs_release_companion_mas = false; + } + uwb_drp_avail_reserve(rsv->rc, &rsv->mas); + uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_ESTABLISHED); + uwb_rsv_callback(rsv); + break; + case UWB_RSV_STATE_O_MOVE_EXPANDING: + rsv->needs_release_companion_mas = true; + uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING); + break; + case UWB_RSV_STATE_O_MOVE_COMBINING: + rsv->needs_release_companion_mas = false; + uwb_drp_avail_reserve(rsv->rc, &mv->companion_mas); + bitmap_or(rsv->mas.bm, rsv->mas.bm, mv->companion_mas.bm, UWB_NUM_MAS); + rsv->mas.safe += mv->companion_mas.safe; + rsv->mas.unsafe += mv->companion_mas.unsafe; + uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_COMBINING); + break; + case UWB_RSV_STATE_O_MOVE_REDUCING: + bitmap_andnot(mv->companion_mas.bm, rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS); + rsv->needs_release_companion_mas = true; + rsv->mas.safe = mv->final_mas.safe; + rsv->mas.unsafe = mv->final_mas.unsafe; + bitmap_copy(rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS); + bitmap_copy(rsv->mas.unsafe_bm, mv->final_mas.unsafe_bm, UWB_NUM_MAS); + uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_REDUCING); + break; + case UWB_RSV_STATE_T_ACCEPTED: + case UWB_RSV_STATE_T_RESIZED: + rsv->needs_release_companion_mas = false; + uwb_drp_avail_reserve(rsv->rc, &rsv->mas); + uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_ACCEPTED); + uwb_rsv_callback(rsv); + break; + case UWB_RSV_STATE_T_DENIED: + uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_DENIED); + break; + case UWB_RSV_STATE_T_CONFLICT: + uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_CONFLICT); + break; + case UWB_RSV_STATE_T_PENDING: + uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_PENDING); + break; + case UWB_RSV_STATE_T_EXPANDING_ACCEPTED: + rsv->needs_release_companion_mas = true; + uwb_drp_avail_reserve(rsv->rc, &mv->companion_mas); + uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_EXPANDING_ACCEPTED); + break; + default: + dev_err(&rsv->rc->uwb_dev.dev, "unhandled state: %s (%d)\n", + uwb_rsv_state_str(new_state), new_state); + } +} + +static void uwb_rsv_handle_timeout_work(struct work_struct *work) +{ + struct uwb_rsv *rsv = container_of(work, struct uwb_rsv, + handle_timeout_work); + struct uwb_rc *rc = rsv->rc; + + mutex_lock(&rc->rsvs_mutex); + + uwb_rsv_dump("TO", rsv); + + switch (rsv->state) { + case UWB_RSV_STATE_O_INITIATED: + if (rsv->is_multicast) { + uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED); + goto unlock; + } + break; + case UWB_RSV_STATE_O_MOVE_EXPANDING: + if (rsv->is_multicast) { + uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_COMBINING); + goto unlock; + } + break; + case UWB_RSV_STATE_O_MOVE_COMBINING: + if (rsv->is_multicast) { + uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_REDUCING); + goto unlock; + } + break; + case UWB_RSV_STATE_O_MOVE_REDUCING: + if (rsv->is_multicast) { + uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED); + goto unlock; + } + break; + case UWB_RSV_STATE_O_ESTABLISHED: + if (rsv->is_multicast) + goto unlock; + break; + case UWB_RSV_STATE_T_EXPANDING_ACCEPTED: + /* + * The time out could be for the main or of the + * companion DRP, assume it's for the companion and + * drop that first. A further time out is required to + * drop the main. + */ + uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_ACCEPTED); + uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas); + goto unlock; + case UWB_RSV_STATE_NONE: + goto unlock; + default: + break; + } + + uwb_rsv_remove(rsv); + +unlock: + mutex_unlock(&rc->rsvs_mutex); +} + +static struct uwb_rsv *uwb_rsv_alloc(struct uwb_rc *rc) +{ + struct uwb_rsv *rsv; + + rsv = kzalloc(sizeof(struct uwb_rsv), GFP_KERNEL); + if (!rsv) + return NULL; + + INIT_LIST_HEAD(&rsv->rc_node); + INIT_LIST_HEAD(&rsv->pal_node); + kref_init(&rsv->kref); + timer_setup(&rsv->timer, uwb_rsv_timer, 0); + + rsv->rc = rc; + INIT_WORK(&rsv->handle_timeout_work, uwb_rsv_handle_timeout_work); + + return rsv; +} + +/** + * uwb_rsv_create - allocate and initialize a UWB reservation structure + * @rc: the radio controller + * @cb: callback to use when the reservation completes or terminates + * @pal_priv: data private to the PAL to be passed in the callback + * + * The callback is called when the state of the reservation changes from: + * + * - pending to accepted + * - pending to denined + * - accepted to terminated + * - pending to terminated + */ +struct uwb_rsv *uwb_rsv_create(struct uwb_rc *rc, uwb_rsv_cb_f cb, void *pal_priv) +{ + struct uwb_rsv *rsv; + + rsv = uwb_rsv_alloc(rc); + if (!rsv) + return NULL; + + rsv->callback = cb; + rsv->pal_priv = pal_priv; + + return rsv; +} +EXPORT_SYMBOL_GPL(uwb_rsv_create); + +void uwb_rsv_remove(struct uwb_rsv *rsv) +{ + uwb_rsv_dump("RM", rsv); + + if (rsv->state != UWB_RSV_STATE_NONE) + uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE); + + if (rsv->needs_release_companion_mas) + uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas); + uwb_drp_avail_release(rsv->rc, &rsv->mas); + + if (uwb_rsv_is_owner(rsv)) + uwb_rsv_put_stream(rsv); + + uwb_dev_put(rsv->owner); + if (rsv->target.type == UWB_RSV_TARGET_DEV) + uwb_dev_put(rsv->target.dev); + + list_del_init(&rsv->rc_node); + uwb_rsv_put(rsv); +} + +/** + * uwb_rsv_destroy - free a UWB reservation structure + * @rsv: the reservation to free + * + * The reservation must already be terminated. + */ +void uwb_rsv_destroy(struct uwb_rsv *rsv) +{ + uwb_rsv_put(rsv); +} +EXPORT_SYMBOL_GPL(uwb_rsv_destroy); + +/** + * usb_rsv_establish - start a reservation establishment + * @rsv: the reservation + * + * The PAL should fill in @rsv's owner, target, type, max_mas, + * min_mas, max_interval and is_multicast fields. If the target is a + * uwb_dev it must be referenced. + * + * The reservation's callback will be called when the reservation is + * accepted, denied or times out. + */ +int uwb_rsv_establish(struct uwb_rsv *rsv) +{ + struct uwb_rc *rc = rsv->rc; + struct uwb_mas_bm available; + struct device *dev = &rc->uwb_dev.dev; + int ret; + + mutex_lock(&rc->rsvs_mutex); + ret = uwb_rsv_get_stream(rsv); + if (ret) { + dev_err(dev, "%s: uwb_rsv_get_stream failed: %d\n", + __func__, ret); + goto out; + } + + rsv->tiebreaker = prandom_u32() & 1; + /* get available mas bitmap */ + uwb_drp_available(rc, &available); + + ret = uwb_rsv_find_best_allocation(rsv, &available, &rsv->mas); + if (ret == UWB_RSV_ALLOC_NOT_FOUND) { + ret = -EBUSY; + uwb_rsv_put_stream(rsv); + dev_err(dev, "%s: uwb_rsv_find_best_allocation failed: %d\n", + __func__, ret); + goto out; + } + + ret = uwb_drp_avail_reserve_pending(rc, &rsv->mas); + if (ret != 0) { + uwb_rsv_put_stream(rsv); + dev_err(dev, "%s: uwb_drp_avail_reserve_pending failed: %d\n", + __func__, ret); + goto out; + } + + uwb_rsv_get(rsv); + list_add_tail(&rsv->rc_node, &rc->reservations); + rsv->owner = &rc->uwb_dev; + uwb_dev_get(rsv->owner); + uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_INITIATED); +out: + mutex_unlock(&rc->rsvs_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(uwb_rsv_establish); + +/** + * uwb_rsv_modify - modify an already established reservation + * @rsv: the reservation to modify + * @max_mas: new maximum MAS to reserve + * @min_mas: new minimum MAS to reserve + * @max_interval: new max_interval to use + * + * FIXME: implement this once there are PALs that use it. + */ +int uwb_rsv_modify(struct uwb_rsv *rsv, int max_mas, int min_mas, int max_interval) +{ + return -ENOSYS; +} +EXPORT_SYMBOL_GPL(uwb_rsv_modify); + +/* + * move an already established reservation (rc->rsvs_mutex must to be + * taken when tis function is called) + */ +int uwb_rsv_try_move(struct uwb_rsv *rsv, struct uwb_mas_bm *available) +{ + struct uwb_rc *rc = rsv->rc; + struct uwb_drp_backoff_win *bow = &rc->bow; + struct device *dev = &rc->uwb_dev.dev; + struct uwb_rsv_move *mv; + int ret = 0; + + if (bow->can_reserve_extra_mases == false) + return -EBUSY; + + mv = &rsv->mv; + + if (uwb_rsv_find_best_allocation(rsv, available, &mv->final_mas) == UWB_RSV_ALLOC_FOUND) { + + if (!bitmap_equal(rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS)) { + /* We want to move the reservation */ + bitmap_andnot(mv->companion_mas.bm, mv->final_mas.bm, rsv->mas.bm, UWB_NUM_MAS); + uwb_drp_avail_reserve_pending(rc, &mv->companion_mas); + uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING); + } + } else { + dev_dbg(dev, "new allocation not found\n"); + } + + return ret; +} + +/* It will try to move every reservation in state O_ESTABLISHED giving + * to the MAS allocator algorithm an availability that is the real one + * plus the allocation already established from the reservation. */ +void uwb_rsv_handle_drp_avail_change(struct uwb_rc *rc) +{ + struct uwb_drp_backoff_win *bow = &rc->bow; + struct uwb_rsv *rsv; + struct uwb_mas_bm mas; + + if (bow->can_reserve_extra_mases == false) + return; + + list_for_each_entry(rsv, &rc->reservations, rc_node) { + if (rsv->state == UWB_RSV_STATE_O_ESTABLISHED || + rsv->state == UWB_RSV_STATE_O_TO_BE_MOVED) { + uwb_drp_available(rc, &mas); + bitmap_or(mas.bm, mas.bm, rsv->mas.bm, UWB_NUM_MAS); + uwb_rsv_try_move(rsv, &mas); + } + } + +} + +/** + * uwb_rsv_terminate - terminate an established reservation + * @rsv: the reservation to terminate + * + * A reservation is terminated by removing the DRP IE from the beacon, + * the other end will consider the reservation to be terminated when + * it does not see the DRP IE for at least mMaxLostBeacons. + * + * If applicable, the reference to the target uwb_dev will be released. + */ +void uwb_rsv_terminate(struct uwb_rsv *rsv) +{ + struct uwb_rc *rc = rsv->rc; + + mutex_lock(&rc->rsvs_mutex); + + if (rsv->state != UWB_RSV_STATE_NONE) + uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE); + + mutex_unlock(&rc->rsvs_mutex); +} +EXPORT_SYMBOL_GPL(uwb_rsv_terminate); + +/** + * uwb_rsv_accept - accept a new reservation from a peer + * @rsv: the reservation + * @cb: call back for reservation changes + * @pal_priv: data to be passed in the above call back + * + * Reservation requests from peers are denied unless a PAL accepts it + * by calling this function. + * + * The PAL call uwb_rsv_destroy() for all accepted reservations before + * calling uwb_pal_unregister(). + */ +void uwb_rsv_accept(struct uwb_rsv *rsv, uwb_rsv_cb_f cb, void *pal_priv) +{ + uwb_rsv_get(rsv); + + rsv->callback = cb; + rsv->pal_priv = pal_priv; + rsv->state = UWB_RSV_STATE_T_ACCEPTED; +} +EXPORT_SYMBOL_GPL(uwb_rsv_accept); + +/* + * Is a received DRP IE for this reservation? + */ +static bool uwb_rsv_match(struct uwb_rsv *rsv, struct uwb_dev *src, + struct uwb_ie_drp *drp_ie) +{ + struct uwb_dev_addr *rsv_src; + int stream; + + stream = uwb_ie_drp_stream_index(drp_ie); + + if (rsv->stream != stream) + return false; + + switch (rsv->target.type) { + case UWB_RSV_TARGET_DEVADDR: + return rsv->stream == stream; + case UWB_RSV_TARGET_DEV: + if (uwb_ie_drp_owner(drp_ie)) + rsv_src = &rsv->owner->dev_addr; + else + rsv_src = &rsv->target.dev->dev_addr; + return uwb_dev_addr_cmp(&src->dev_addr, rsv_src) == 0; + } + return false; +} + +static struct uwb_rsv *uwb_rsv_new_target(struct uwb_rc *rc, + struct uwb_dev *src, + struct uwb_ie_drp *drp_ie) +{ + struct uwb_rsv *rsv; + struct uwb_pal *pal; + enum uwb_rsv_state state; + + rsv = uwb_rsv_alloc(rc); + if (!rsv) + return NULL; + + rsv->rc = rc; + rsv->owner = src; + uwb_dev_get(rsv->owner); + rsv->target.type = UWB_RSV_TARGET_DEV; + rsv->target.dev = &rc->uwb_dev; + uwb_dev_get(&rc->uwb_dev); + rsv->type = uwb_ie_drp_type(drp_ie); + rsv->stream = uwb_ie_drp_stream_index(drp_ie); + uwb_drp_ie_to_bm(&rsv->mas, drp_ie); + + /* + * See if any PALs are interested in this reservation. If not, + * deny the request. + */ + rsv->state = UWB_RSV_STATE_T_DENIED; + mutex_lock(&rc->uwb_dev.mutex); + list_for_each_entry(pal, &rc->pals, node) { + if (pal->new_rsv) + pal->new_rsv(pal, rsv); + if (rsv->state == UWB_RSV_STATE_T_ACCEPTED) + break; + } + mutex_unlock(&rc->uwb_dev.mutex); + + list_add_tail(&rsv->rc_node, &rc->reservations); + state = rsv->state; + rsv->state = UWB_RSV_STATE_NONE; + + /* FIXME: do something sensible here */ + if (state == UWB_RSV_STATE_T_ACCEPTED + && uwb_drp_avail_reserve_pending(rc, &rsv->mas) == -EBUSY) { + /* FIXME: do something sensible here */ + } else { + uwb_rsv_set_state(rsv, state); + } + + return rsv; +} + +/** + * uwb_rsv_get_usable_mas - get the bitmap of the usable MAS of a reservations + * @rsv: the reservation. + * @mas: returns the available MAS. + * + * The usable MAS of a reservation may be less than the negotiated MAS + * if alien BPs are present. + */ +void uwb_rsv_get_usable_mas(struct uwb_rsv *rsv, struct uwb_mas_bm *mas) +{ + bitmap_zero(mas->bm, UWB_NUM_MAS); + bitmap_andnot(mas->bm, rsv->mas.bm, rsv->rc->cnflt_alien_bitmap.bm, UWB_NUM_MAS); +} +EXPORT_SYMBOL_GPL(uwb_rsv_get_usable_mas); + +/** + * uwb_rsv_find - find a reservation for a received DRP IE. + * @rc: the radio controller + * @src: source of the DRP IE + * @drp_ie: the DRP IE + * + * If the reservation cannot be found and the DRP IE is from a peer + * attempting to establish a new reservation, create a new reservation + * and add it to the list. + */ +struct uwb_rsv *uwb_rsv_find(struct uwb_rc *rc, struct uwb_dev *src, + struct uwb_ie_drp *drp_ie) +{ + struct uwb_rsv *rsv; + + list_for_each_entry(rsv, &rc->reservations, rc_node) { + if (uwb_rsv_match(rsv, src, drp_ie)) + return rsv; + } + + if (uwb_ie_drp_owner(drp_ie)) + return uwb_rsv_new_target(rc, src, drp_ie); + + return NULL; +} + +/* + * Go through all the reservations and check for timeouts and (if + * necessary) update their DRP IEs. + * + * FIXME: look at building the SET_DRP_IE command here rather than + * having to rescan the list in uwb_rc_send_all_drp_ie(). + */ +static bool uwb_rsv_update_all(struct uwb_rc *rc) +{ + struct uwb_rsv *rsv, *t; + bool ie_updated = false; + + list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) { + if (!rsv->ie_valid) { + uwb_drp_ie_update(rsv); + ie_updated = true; + } + } + + return ie_updated; +} + +void uwb_rsv_queue_update(struct uwb_rc *rc) +{ + unsigned long delay_us = UWB_MAS_LENGTH_US * UWB_MAS_PER_ZONE; + + queue_delayed_work(rc->rsv_workq, &rc->rsv_update_work, usecs_to_jiffies(delay_us)); +} + +/** + * uwb_rsv_sched_update - schedule an update of the DRP IEs + * @rc: the radio controller. + * + * To improve performance and ensure correctness with [ECMA-368] the + * number of SET-DRP-IE commands that are done are limited. + * + * DRP IEs update come from two sources: DRP events from the hardware + * which all occur at the beginning of the superframe ('syncronous' + * events) and reservation establishment/termination requests from + * PALs or timers ('asynchronous' events). + * + * A delayed work ensures that all the synchronous events result in + * one SET-DRP-IE command. + * + * Additional logic (the set_drp_ie_pending and rsv_updated_postponed + * flags) will prevent an asynchrous event starting a SET-DRP-IE + * command if one is currently awaiting a response. + * + * FIXME: this does leave a window where an asynchrous event can delay + * the SET-DRP-IE for a synchronous event by one superframe. + */ +void uwb_rsv_sched_update(struct uwb_rc *rc) +{ + spin_lock_irq(&rc->rsvs_lock); + if (!delayed_work_pending(&rc->rsv_update_work)) { + if (rc->set_drp_ie_pending > 0) { + rc->set_drp_ie_pending++; + goto unlock; + } + uwb_rsv_queue_update(rc); + } +unlock: + spin_unlock_irq(&rc->rsvs_lock); +} + +/* + * Update DRP IEs and, if necessary, the DRP Availability IE and send + * the updated IEs to the radio controller. + */ +static void uwb_rsv_update_work(struct work_struct *work) +{ + struct uwb_rc *rc = container_of(work, struct uwb_rc, + rsv_update_work.work); + bool ie_updated; + + mutex_lock(&rc->rsvs_mutex); + + ie_updated = uwb_rsv_update_all(rc); + + if (!rc->drp_avail.ie_valid) { + uwb_drp_avail_ie_update(rc); + ie_updated = true; + } + + if (ie_updated && (rc->set_drp_ie_pending == 0)) + uwb_rc_send_all_drp_ie(rc); + + mutex_unlock(&rc->rsvs_mutex); +} + +static void uwb_rsv_alien_bp_work(struct work_struct *work) +{ + struct uwb_rc *rc = container_of(work, struct uwb_rc, + rsv_alien_bp_work.work); + struct uwb_rsv *rsv; + + mutex_lock(&rc->rsvs_mutex); + + list_for_each_entry(rsv, &rc->reservations, rc_node) { + if (rsv->type != UWB_DRP_TYPE_ALIEN_BP) { + uwb_rsv_callback(rsv); + } + } + + mutex_unlock(&rc->rsvs_mutex); +} + +static void uwb_rsv_timer(struct timer_list *t) +{ + struct uwb_rsv *rsv = from_timer(rsv, t, timer); + + queue_work(rsv->rc->rsv_workq, &rsv->handle_timeout_work); +} + +/** + * uwb_rsv_remove_all - remove all reservations + * @rc: the radio controller + * + * A DRP IE update is not done. + */ +void uwb_rsv_remove_all(struct uwb_rc *rc) +{ + struct uwb_rsv *rsv, *t; + + mutex_lock(&rc->rsvs_mutex); + list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) { + if (rsv->state != UWB_RSV_STATE_NONE) + uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE); + del_timer_sync(&rsv->timer); + } + /* Cancel any postponed update. */ + rc->set_drp_ie_pending = 0; + mutex_unlock(&rc->rsvs_mutex); + + cancel_delayed_work_sync(&rc->rsv_update_work); + flush_workqueue(rc->rsv_workq); + + mutex_lock(&rc->rsvs_mutex); + list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) { + uwb_rsv_remove(rsv); + } + mutex_unlock(&rc->rsvs_mutex); +} + +void uwb_rsv_init(struct uwb_rc *rc) +{ + INIT_LIST_HEAD(&rc->reservations); + INIT_LIST_HEAD(&rc->cnflt_alien_list); + mutex_init(&rc->rsvs_mutex); + spin_lock_init(&rc->rsvs_lock); + INIT_DELAYED_WORK(&rc->rsv_update_work, uwb_rsv_update_work); + INIT_DELAYED_WORK(&rc->rsv_alien_bp_work, uwb_rsv_alien_bp_work); + rc->bow.can_reserve_extra_mases = true; + rc->bow.total_expired = 0; + rc->bow.window = UWB_DRP_BACKOFF_WIN_MIN >> 1; + timer_setup(&rc->bow.timer, uwb_rsv_backoff_win_timer, 0); + + bitmap_complement(rc->uwb_dev.streams, rc->uwb_dev.streams, UWB_NUM_STREAMS); +} + +int uwb_rsv_setup(struct uwb_rc *rc) +{ + char name[16]; + + snprintf(name, sizeof(name), "%s_rsvd", dev_name(&rc->uwb_dev.dev)); + rc->rsv_workq = create_singlethread_workqueue(name); + if (rc->rsv_workq == NULL) + return -ENOMEM; + + return 0; +} + +void uwb_rsv_cleanup(struct uwb_rc *rc) +{ + uwb_rsv_remove_all(rc); + destroy_workqueue(rc->rsv_workq); +} |