linux_dsm_epyc7002/drivers/net/wireless/intel/iwlwifi/fw/notif-wait.c

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/******************************************************************************
*
* This file is provided under a dual BSD/GPLv2 license. When using or
* redistributing this file, you may do so under either license.
*
* GPL LICENSE SUMMARY
*
* Copyright(c) 2007 - 2014 Intel Corporation. All rights reserved.
* Copyright(c) 2015 - 2017 Intel Deutschland GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License 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.
*
* The full GNU General Public License is included in this distribution
* in the file called COPYING.
*
* Contact Information:
* Intel Linux Wireless <linuxwifi@intel.com>
* Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
*
* BSD LICENSE
*
* Copyright(c) 2005 - 2014 Intel Corporation. All rights reserved.
* Copyright(c) 2015 - 2017 Intel Deutschland GmbH
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*****************************************************************************/
#include <linux/sched.h>
#include <linux/export.h>
#include "iwl-drv.h"
#include "notif-wait.h"
void iwl_notification_wait_init(struct iwl_notif_wait_data *notif_wait)
{
spin_lock_init(&notif_wait->notif_wait_lock);
INIT_LIST_HEAD(&notif_wait->notif_waits);
init_waitqueue_head(&notif_wait->notif_waitq);
}
IWL_EXPORT_SYMBOL(iwl_notification_wait_init);
iwlwifi: split the handler and the wake parts of the notification infra The notification infrastructure (iwl_notification_wait_* functions) allows to wait until a list of notifications will come up from the firmware and to run a special handler (notif_wait handler) when those are received. The operation mode notifies the notification infrastructure about any Rx being received by the mean of iwl_notification_wait_notify() which will do two things: 1) call the notif_wait handler 2) wakeup the thread that was waiting for the notification Typically, only after those two steps happened, the operation mode will run its own handler for the notification that was received from the firmware. This means that the thread that was waiting for that notification can be running before the operation mode's handler was called. When the operation mode's handler is ASYNC, things get even worse since the thread that was waiting for the notification isn't even guaranteed that the ASYNC callback was added to async_handlers_list before it starts to run. This means that even calling iwl_mvm_wait_for_async_handlers() can't guarantee that absolutely everything related to that notification has run. The following can happen: Thread sending the command Operation mode's Rx path -------------------------- ------------------------ iwl_init_notification_wait() iwl_mvm_send_cmd() iwl_mvm_rx_common() iwl_notification_wait_notify() iwl_mvm_wait_for_async_handlers() // Possibly free some data // structure list_add_tail(async_handlers_list); schedule_work(async_handlers_wk); // Access the freed structure Split the 'run notif_wait's handler' and the 'wake up the thread' parts to fix this. This allows the operation mode to do the following: Thread sending the command Operation mode's Rx path -------------------------- ------------------------ iwl_init_notification_wait() iwl_mvm_send_cmd() iwl_mvm_rx_common() iwl_notification_wait() // Will run the notif_wait's handler list_add_tail(async_handlers_list); schedule_work(async_handlers_wk); iwl_notification_notify() iwl_mvm_wait_for_async_handlers() This way, the waiter is guaranteed that all the handlers have been run (if SYNC), or at least enqueued (if ASYNC) by the time it wakes up. Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
2017-02-13 16:29:16 +07:00
bool iwl_notification_wait(struct iwl_notif_wait_data *notif_wait,
struct iwl_rx_packet *pkt)
{
bool triggered = false;
if (!list_empty(&notif_wait->notif_waits)) {
struct iwl_notification_wait *w;
spin_lock(&notif_wait->notif_wait_lock);
list_for_each_entry(w, &notif_wait->notif_waits, list) {
int i;
bool found = false;
/*
* If it already finished (triggered) or has been
* aborted then don't evaluate it again to avoid races,
* Otherwise the function could be called again even
* though it returned true before
*/
if (w->triggered || w->aborted)
continue;
for (i = 0; i < w->n_cmds; i++) {
u16 rec_id = WIDE_ID(pkt->hdr.group_id,
pkt->hdr.cmd);
if (w->cmds[i] == rec_id ||
(!iwl_cmd_groupid(w->cmds[i]) &&
DEF_ID(w->cmds[i]) == rec_id)) {
found = true;
break;
}
}
if (!found)
continue;
if (!w->fn || w->fn(notif_wait, pkt, w->fn_data)) {
w->triggered = true;
triggered = true;
}
}
spin_unlock(&notif_wait->notif_wait_lock);
}
iwlwifi: split the handler and the wake parts of the notification infra The notification infrastructure (iwl_notification_wait_* functions) allows to wait until a list of notifications will come up from the firmware and to run a special handler (notif_wait handler) when those are received. The operation mode notifies the notification infrastructure about any Rx being received by the mean of iwl_notification_wait_notify() which will do two things: 1) call the notif_wait handler 2) wakeup the thread that was waiting for the notification Typically, only after those two steps happened, the operation mode will run its own handler for the notification that was received from the firmware. This means that the thread that was waiting for that notification can be running before the operation mode's handler was called. When the operation mode's handler is ASYNC, things get even worse since the thread that was waiting for the notification isn't even guaranteed that the ASYNC callback was added to async_handlers_list before it starts to run. This means that even calling iwl_mvm_wait_for_async_handlers() can't guarantee that absolutely everything related to that notification has run. The following can happen: Thread sending the command Operation mode's Rx path -------------------------- ------------------------ iwl_init_notification_wait() iwl_mvm_send_cmd() iwl_mvm_rx_common() iwl_notification_wait_notify() iwl_mvm_wait_for_async_handlers() // Possibly free some data // structure list_add_tail(async_handlers_list); schedule_work(async_handlers_wk); // Access the freed structure Split the 'run notif_wait's handler' and the 'wake up the thread' parts to fix this. This allows the operation mode to do the following: Thread sending the command Operation mode's Rx path -------------------------- ------------------------ iwl_init_notification_wait() iwl_mvm_send_cmd() iwl_mvm_rx_common() iwl_notification_wait() // Will run the notif_wait's handler list_add_tail(async_handlers_list); schedule_work(async_handlers_wk); iwl_notification_notify() iwl_mvm_wait_for_async_handlers() This way, the waiter is guaranteed that all the handlers have been run (if SYNC), or at least enqueued (if ASYNC) by the time it wakes up. Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
2017-02-13 16:29:16 +07:00
return triggered;
}
iwlwifi: split the handler and the wake parts of the notification infra The notification infrastructure (iwl_notification_wait_* functions) allows to wait until a list of notifications will come up from the firmware and to run a special handler (notif_wait handler) when those are received. The operation mode notifies the notification infrastructure about any Rx being received by the mean of iwl_notification_wait_notify() which will do two things: 1) call the notif_wait handler 2) wakeup the thread that was waiting for the notification Typically, only after those two steps happened, the operation mode will run its own handler for the notification that was received from the firmware. This means that the thread that was waiting for that notification can be running before the operation mode's handler was called. When the operation mode's handler is ASYNC, things get even worse since the thread that was waiting for the notification isn't even guaranteed that the ASYNC callback was added to async_handlers_list before it starts to run. This means that even calling iwl_mvm_wait_for_async_handlers() can't guarantee that absolutely everything related to that notification has run. The following can happen: Thread sending the command Operation mode's Rx path -------------------------- ------------------------ iwl_init_notification_wait() iwl_mvm_send_cmd() iwl_mvm_rx_common() iwl_notification_wait_notify() iwl_mvm_wait_for_async_handlers() // Possibly free some data // structure list_add_tail(async_handlers_list); schedule_work(async_handlers_wk); // Access the freed structure Split the 'run notif_wait's handler' and the 'wake up the thread' parts to fix this. This allows the operation mode to do the following: Thread sending the command Operation mode's Rx path -------------------------- ------------------------ iwl_init_notification_wait() iwl_mvm_send_cmd() iwl_mvm_rx_common() iwl_notification_wait() // Will run the notif_wait's handler list_add_tail(async_handlers_list); schedule_work(async_handlers_wk); iwl_notification_notify() iwl_mvm_wait_for_async_handlers() This way, the waiter is guaranteed that all the handlers have been run (if SYNC), or at least enqueued (if ASYNC) by the time it wakes up. Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
2017-02-13 16:29:16 +07:00
IWL_EXPORT_SYMBOL(iwl_notification_wait);
void iwl_abort_notification_waits(struct iwl_notif_wait_data *notif_wait)
{
struct iwl_notification_wait *wait_entry;
spin_lock(&notif_wait->notif_wait_lock);
list_for_each_entry(wait_entry, &notif_wait->notif_waits, list)
wait_entry->aborted = true;
spin_unlock(&notif_wait->notif_wait_lock);
wake_up_all(&notif_wait->notif_waitq);
}
IWL_EXPORT_SYMBOL(iwl_abort_notification_waits);
void
iwl_init_notification_wait(struct iwl_notif_wait_data *notif_wait,
struct iwl_notification_wait *wait_entry,
const u16 *cmds, int n_cmds,
bool (*fn)(struct iwl_notif_wait_data *notif_wait,
struct iwl_rx_packet *pkt, void *data),
void *fn_data)
{
if (WARN_ON(n_cmds > MAX_NOTIF_CMDS))
n_cmds = MAX_NOTIF_CMDS;
wait_entry->fn = fn;
wait_entry->fn_data = fn_data;
wait_entry->n_cmds = n_cmds;
memcpy(wait_entry->cmds, cmds, n_cmds * sizeof(u16));
wait_entry->triggered = false;
wait_entry->aborted = false;
spin_lock_bh(&notif_wait->notif_wait_lock);
list_add(&wait_entry->list, &notif_wait->notif_waits);
spin_unlock_bh(&notif_wait->notif_wait_lock);
}
IWL_EXPORT_SYMBOL(iwl_init_notification_wait);
void iwl_remove_notification(struct iwl_notif_wait_data *notif_wait,
struct iwl_notification_wait *wait_entry)
{
spin_lock_bh(&notif_wait->notif_wait_lock);
list_del(&wait_entry->list);
spin_unlock_bh(&notif_wait->notif_wait_lock);
}
IWL_EXPORT_SYMBOL(iwl_remove_notification);
int iwl_wait_notification(struct iwl_notif_wait_data *notif_wait,
struct iwl_notification_wait *wait_entry,
unsigned long timeout)
{
int ret;
ret = wait_event_timeout(notif_wait->notif_waitq,
wait_entry->triggered || wait_entry->aborted,
timeout);
iwl_remove_notification(notif_wait, wait_entry);
if (wait_entry->aborted)
return -EIO;
/* return value is always >= 0 */
if (ret <= 0)
return -ETIMEDOUT;
return 0;
}
IWL_EXPORT_SYMBOL(iwl_wait_notification);