/*
* 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(unsigned long arg);
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)
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(unsigned long arg)
{
struct uwb_drp_backoff_win *bow = (struct uwb_drp_backoff_win *)arg;
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->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_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;
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);
init_timer(&rsv->timer);
rsv->timer.function = uwb_rsv_timer;
rsv->timer.data = (unsigned long)rsv;
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;
int ret;
mutex_lock(&rc->rsvs_mutex);
ret = uwb_rsv_get_stream(rsv);
if (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);
goto out;
}
ret = uwb_drp_avail_reserve_pending(rc, &rsv->mas);
if (ret != 0) {
uwb_rsv_put_stream(rsv);
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_bh(&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_bh(&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) {
rsv->callback(rsv);
}
}
mutex_unlock(&rc->rsvs_mutex);
}
static void uwb_rsv_timer(unsigned long arg)
{
struct uwb_rsv *rsv = (struct uwb_rsv *)arg;
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;
init_timer(&rc->bow.timer);
rc->bow.timer.function = uwb_rsv_backoff_win_timer;
rc->bow.timer.data = (unsigned long)&rc->bow;
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);
}
