freebsd-skq/sys/dev/isci/isci_timer.c
smh dd63bf99a2 Prevent overflow issues in timeout processing
Previously, any timeout value for which (timeout * hz) will overflow the
signed integer, will give weird results, since callout(9) routines will
convert negative values of ticks to '1'. For unsigned integer overflow we
will get sufficiently smaller timeout values than expected.

Switch from callout_reset, which requires conversion to int based ticks
to callout_reset_sbt to avoid this.

Also correct isci to correctly resolve ccb timeout.

This was based on the original work done by Eygene Ryabinkin
<rea@freebsd.org> back in 5 Aug 2011 which used a macro to help avoid
the overlow.

Differential Revision:	https://reviews.freebsd.org/D1157
Reviewed by:	mav, davide
MFC after:	1 month
Sponsored by:	Multiplay
2014-11-21 21:01:24 +00:00

167 lines
6.1 KiB
C

/*-
* BSD LICENSE
*
* Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
* 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.
*
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <dev/isci/isci.h>
#include <dev/isci/scil/scif_user_callback.h>
static void
isci_timer_timeout(void *arg)
{
struct ISCI_TIMER *timer = (struct ISCI_TIMER *)arg;
isci_log_message(3, "TIMER", "timeout %p\n", timer);
/* callout_stop() will *not* keep the timer from running if it is
* pending. callout_drain() cannot be called from interrupt context,
* because it may cause thread to sleep which is not allowed in
* interrupt context. So instead, check the is_started flag to see if
* the timer routine should actually be run or not.
*/
if (timer->is_started == TRUE)
timer->callback(timer->cookie);
}
/**
* @brief This callback method asks the user to start the supplied timer.
*
* @warning All timers in the system started by the SCI Framework are one
* shot timers. Therefore, the SCI user should make sure that it
* removes the timer from it's list when a timer actually fires.
* Additionally, SCI Framework user's should be able to handle
* calls from the SCI Framework to stop a timer that may already
* be stopped.
*
* @param[in] controller This parameter specifies the controller with
* which this timer is to associated.
* @param[in] timer This parameter specifies the timer to be started.
* @param[in] milliseconds This parameter specifies the number of
* milliseconds for which to stall. The operating system driver
* is allowed to round this value up where necessary.
*
* @return none
*/
void
scif_cb_timer_start(SCI_CONTROLLER_HANDLE_T controller, void *timer,
uint32_t milliseconds)
{
struct ISCI_TIMER *isci_timer = (struct ISCI_TIMER *)timer;
isci_timer->is_started = TRUE;
isci_log_message(3, "TIMER", "start %p %d\n", timer, milliseconds);
callout_reset_sbt(&isci_timer->callout, SBT_1MS * milliseconds, 0,
isci_timer_timeout, timer, 0);
}
/**
* @brief This callback method asks the user to stop the supplied timer.
*
* @param[in] controller This parameter specifies the controller with
* which this timer is to associated.
* @param[in] timer This parameter specifies the timer to be stopped.
*
* @return none
*/
void
scif_cb_timer_stop(SCI_CONTROLLER_HANDLE_T controller, void *timer)
{
struct ISCI_TIMER *isci_timer = (struct ISCI_TIMER *)timer;
isci_log_message(3, "TIMER", "stop %p\n", timer);
isci_timer->is_started = FALSE;
callout_stop(&isci_timer->callout);
}
/**
* @brief This callback method asks the user to create a timer and provide
* a handle for this timer for use in further timer interactions.
*
* @warning The "timer_callback" method should be executed in a mutually
* exlusive manner from the controller completion handler
* handler (refer to scic_controller_get_handler_methods()).
*
* @param[in] timer_callback This parameter specifies the callback method
* to be invoked whenever the timer expires.
* @param[in] controller This parameter specifies the controller with
* which this timer is to be associated.
* @param[in] cookie This parameter specifies a piece of information that
* the user must retain. This cookie is to be supplied by the
* user anytime a timeout occurs for the created timer.
*
* @return This method returns a handle to a timer object created by the
* user. The handle will be utilized for all further interactions
* relating to this timer.
*/
void *
scif_cb_timer_create(SCI_CONTROLLER_HANDLE_T scif_controller,
SCI_TIMER_CALLBACK_T timer_callback, void *cookie)
{
struct ISCI_CONTROLLER *isci_controller = (struct ISCI_CONTROLLER *)
sci_object_get_association(scif_controller);
struct ISCI_TIMER *timer;
sci_pool_get(isci_controller->timer_pool, timer);
callout_init_mtx(&timer->callout, &isci_controller->lock, FALSE);
timer->callback = timer_callback;
timer->cookie = cookie;
timer->is_started = FALSE;
isci_log_message(3, "TIMER", "create %p %p %p\n", timer, timer_callback, cookie);
return (timer);
}
/**
* @brief This callback method asks the user to destory the supplied timer.
*
* @param[in] controller This parameter specifies the controller with
* which this timer is to associated.
* @param[in] timer This parameter specifies the timer to be destroyed.
*
* @return none
*/
void
scif_cb_timer_destroy(SCI_CONTROLLER_HANDLE_T scif_controller,
void *timer_handle)
{
struct ISCI_CONTROLLER *isci_controller = (struct ISCI_CONTROLLER *)
sci_object_get_association(scif_controller);
scif_cb_timer_stop(scif_controller, timer_handle);
sci_pool_put(isci_controller->timer_pool, (struct ISCI_TIMER *)timer_handle);
isci_log_message(3, "TIMER", "destroy %p\n", timer_handle);
}