Current File : //usr/src/vboxhost-6.0.14/vboxdrv/r0drv/linux/timer-r0drv-linux.c
/* $Id: timer-r0drv-linux.c 129718 2019-04-01 10:39:12Z bird $ */
/** @file
* IPRT - Timers, Ring-0 Driver, Linux.
*/
/*
* Copyright (C) 2006-2019 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
* VirtualBox OSE distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*/
/*********************************************************************************************************************************
* Header Files *
*********************************************************************************************************************************/
#include "the-linux-kernel.h"
#include "internal/iprt.h"
#include <iprt/timer.h>
#include <iprt/time.h>
#include <iprt/mp.h>
#include <iprt/cpuset.h>
#include <iprt/spinlock.h>
#include <iprt/err.h>
#include <iprt/asm.h>
#include <iprt/assert.h>
#include <iprt/alloc.h>
#include "internal/magics.h"
/** @def RTTIMER_LINUX_WITH_HRTIMER
* Whether to use high resolution timers. */
#if !defined(RTTIMER_LINUX_WITH_HRTIMER) \
&& defined(IPRT_LINUX_HAS_HRTIMER)
# define RTTIMER_LINUX_WITH_HRTIMER
#endif
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 31)
# define mod_timer_pinned mod_timer
# define HRTIMER_MODE_ABS_PINNED HRTIMER_MODE_ABS
#endif
/*********************************************************************************************************************************
* Structures and Typedefs *
*********************************************************************************************************************************/
/**
* Timer state machine.
*
* This is used to try handle the issues with MP events and
* timers that runs on all CPUs. It's relatively nasty :-/
*/
typedef enum RTTIMERLNXSTATE
{
/** Stopped. */
RTTIMERLNXSTATE_STOPPED = 0,
/** Transient state; next ACTIVE. */
RTTIMERLNXSTATE_STARTING,
/** Transient state; next ACTIVE. (not really necessary) */
RTTIMERLNXSTATE_MP_STARTING,
/** Active. */
RTTIMERLNXSTATE_ACTIVE,
/** Active and in callback; next ACTIVE, STOPPED or CALLBACK_DESTROYING. */
RTTIMERLNXSTATE_CALLBACK,
/** Stopped while in the callback; next STOPPED. */
RTTIMERLNXSTATE_CB_STOPPING,
/** Restarted while in the callback; next ACTIVE, STOPPED, DESTROYING. */
RTTIMERLNXSTATE_CB_RESTARTING,
/** The callback shall destroy the timer; next STOPPED. */
RTTIMERLNXSTATE_CB_DESTROYING,
/** Transient state; next STOPPED. */
RTTIMERLNXSTATE_STOPPING,
/** Transient state; next STOPPED. */
RTTIMERLNXSTATE_MP_STOPPING,
/** The usual 32-bit hack. */
RTTIMERLNXSTATE_32BIT_HACK = 0x7fffffff
} RTTIMERLNXSTATE;
/**
* A Linux sub-timer.
*/
typedef struct RTTIMERLNXSUBTIMER
{
/** Timer specific data. */
union
{
#if defined(RTTIMER_LINUX_WITH_HRTIMER)
/** High resolution timer. */
struct
{
/** The linux timer structure. */
struct hrtimer LnxTimer;
} Hr;
#endif
/** Standard timer. */
struct
{
/** The linux timer structure. */
struct timer_list LnxTimer;
/** The start of the current run (ns).
* This is used to calculate when the timer ought to fire the next time. */
uint64_t u64NextTS;
/** The u64NextTS in jiffies. */
unsigned long ulNextJiffies;
/** Set when starting or changing the timer so that u64StartTs
* and u64NextTS gets reinitialized (eliminating some jitter). */
bool volatile fFirstAfterChg;
} Std;
} u;
/** The current tick number. */
uint64_t iTick;
/** Restart the single shot timer at this specific time.
* Used when a single shot timer is restarted from the callback. */
uint64_t volatile uNsRestartAt;
/** Pointer to the parent timer. */
PRTTIMER pParent;
/** The current sub-timer state. */
RTTIMERLNXSTATE volatile enmState;
} RTTIMERLNXSUBTIMER;
/** Pointer to a linux sub-timer. */
typedef RTTIMERLNXSUBTIMER *PRTTIMERLNXSUBTIMER;
/**
* The internal representation of an Linux timer handle.
*/
typedef struct RTTIMER
{
/** Magic.
* This is RTTIMER_MAGIC, but changes to something else before the timer
* is destroyed to indicate clearly that thread should exit. */
uint32_t volatile u32Magic;
/** Spinlock synchronizing the fSuspended and MP event handling.
* This is NIL_RTSPINLOCK if cCpus == 1. */
RTSPINLOCK hSpinlock;
/** Flag indicating that the timer is suspended. */
bool volatile fSuspended;
/** Whether the timer must run on one specific CPU or not. */
bool fSpecificCpu;
#ifdef CONFIG_SMP
/** Whether the timer must run on all CPUs or not. */
bool fAllCpus;
#endif /* else: All -> specific on non-SMP kernels */
/** Whether it is a high resolution timer or a standard one. */
bool fHighRes;
/** The id of the CPU it must run on if fSpecificCpu is set. */
RTCPUID idCpu;
/** The number of CPUs this timer should run on. */
RTCPUID cCpus;
/** Callback. */
PFNRTTIMER pfnTimer;
/** User argument. */
void *pvUser;
/** The timer interval. 0 if one-shot. */
uint64_t volatile u64NanoInterval;
/** This is set to the number of jiffies between ticks if the interval is
* an exact number of jiffies. (Standard timers only.) */
unsigned long volatile cJiffies;
/** The change interval spinlock for standard timers only. */
spinlock_t ChgIntLock;
/** Workqueue item for delayed destruction. */
RTR0LNXWORKQUEUEITEM DtorWorkqueueItem;
/** Sub-timers.
* Normally there is just one, but for RTTIMER_FLAGS_CPU_ALL this will contain
* an entry for all possible cpus. In that case the index will be the same as
* for the RTCpuSet. */
RTTIMERLNXSUBTIMER aSubTimers[1];
} RTTIMER;
/**
* A rtTimerLinuxStartOnCpu and rtTimerLinuxStartOnCpu argument package.
*/
typedef struct RTTIMERLINUXSTARTONCPUARGS
{
/** The current time (RTTimeSystemNanoTS). */
uint64_t u64Now;
/** When to start firing (delta). */
uint64_t u64First;
} RTTIMERLINUXSTARTONCPUARGS;
/** Pointer to a rtTimerLinuxStartOnCpu argument package. */
typedef RTTIMERLINUXSTARTONCPUARGS *PRTTIMERLINUXSTARTONCPUARGS;
/*********************************************************************************************************************************
* Internal Functions *
*********************************************************************************************************************************/
#ifdef CONFIG_SMP
static DECLCALLBACK(void) rtTimerLinuxMpEvent(RTMPEVENT enmEvent, RTCPUID idCpu, void *pvUser);
#endif
#if 0
#define DEBUG_HACKING
#include <iprt/string.h>
#include <iprt/asm-amd64-x86.h>
static void myLogBackdoorPrintf(const char *pszFormat, ...)
{
char szTmp[256];
va_list args;
size_t cb;
cb = RTStrPrintf(szTmp, sizeof(szTmp) - 10, "%d: ", RTMpCpuId());
va_start(args, pszFormat);
cb += RTStrPrintfV(&szTmp[cb], sizeof(szTmp) - cb, pszFormat, args);
va_end(args);
ASMOutStrU8(0x504, (uint8_t *)&szTmp[0], cb);
}
# define RTAssertMsg1Weak(pszExpr, uLine, pszFile, pszFunction) \
myLogBackdoorPrintf("\n!!Guest Assertion failed!!\n%s(%d) %s\n%s\n", uLine, pszFile, pszFunction, (pszExpr))
# define RTAssertMsg2Weak myLogBackdoorPrintf
# define RTTIMERLNX_LOG(a) myLogBackdoorPrintf a
#else
# define RTTIMERLNX_LOG(a) do { } while (0)
#endif
/**
* Sets the state.
*/
DECLINLINE(void) rtTimerLnxSetState(RTTIMERLNXSTATE volatile *penmState, RTTIMERLNXSTATE enmNewState)
{
#ifdef DEBUG_HACKING
RTTIMERLNX_LOG(("set %d -> %d\n", *penmState, enmNewState));
#endif
ASMAtomicWriteU32((uint32_t volatile *)penmState, enmNewState);
}
/**
* Sets the state if it has a certain value.
*
* @return true if xchg was done.
* @return false if xchg wasn't done.
*/
#ifdef DEBUG_HACKING
#define rtTimerLnxCmpXchgState(penmState, enmNewState, enmCurState) rtTimerLnxCmpXchgStateDebug(penmState, enmNewState, enmCurState, __LINE__)
static bool rtTimerLnxCmpXchgStateDebug(RTTIMERLNXSTATE volatile *penmState, RTTIMERLNXSTATE enmNewState,
RTTIMERLNXSTATE enmCurState, uint32_t uLine)
{
RTTIMERLNXSTATE enmOldState = enmCurState;
bool fRc = ASMAtomicCmpXchgExU32((uint32_t volatile *)penmState, enmNewState, enmCurState, (uint32_t *)&enmOldState);
RTTIMERLNX_LOG(("cxg %d -> %d - %d at %u\n", enmOldState, enmNewState, fRc, uLine));
return fRc;
}
#else
DECLINLINE(bool) rtTimerLnxCmpXchgState(RTTIMERLNXSTATE volatile *penmState, RTTIMERLNXSTATE enmNewState,
RTTIMERLNXSTATE enmCurState)
{
return ASMAtomicCmpXchgU32((uint32_t volatile *)penmState, enmNewState, enmCurState);
}
#endif
/**
* Gets the state.
*/
DECLINLINE(RTTIMERLNXSTATE) rtTimerLnxGetState(RTTIMERLNXSTATE volatile *penmState)
{
return (RTTIMERLNXSTATE)ASMAtomicUoReadU32((uint32_t volatile *)penmState);
}
#ifdef RTTIMER_LINUX_WITH_HRTIMER
/**
* Converts a nano second time stamp to ktime_t.
*
* ASSUMES RTTimeSystemNanoTS() is implemented using ktime_get_ts().
*
* @returns ktime_t.
* @param cNanoSecs Nanoseconds.
*/
DECLINLINE(ktime_t) rtTimerLnxNanoToKt(uint64_t cNanoSecs)
{
/* With some luck the compiler optimizes the division out of this... (Bet it doesn't.) */
return ktime_set(cNanoSecs / 1000000000, cNanoSecs % 1000000000);
}
/**
* Converts ktime_t to a nano second time stamp.
*
* ASSUMES RTTimeSystemNanoTS() is implemented using ktime_get_ts().
*
* @returns nano second time stamp.
* @param Kt ktime_t.
*/
DECLINLINE(uint64_t) rtTimerLnxKtToNano(ktime_t Kt)
{
return ktime_to_ns(Kt);
}
#endif /* RTTIMER_LINUX_WITH_HRTIMER */
/**
* Converts a nano second interval to jiffies.
*
* @returns Jiffies.
* @param cNanoSecs Nanoseconds.
*/
DECLINLINE(unsigned long) rtTimerLnxNanoToJiffies(uint64_t cNanoSecs)
{
/* this can be made even better... */
if (cNanoSecs > (uint64_t)TICK_NSEC * MAX_JIFFY_OFFSET)
return MAX_JIFFY_OFFSET;
# if ARCH_BITS == 32
if (RT_LIKELY(cNanoSecs <= UINT32_MAX))
return ((uint32_t)cNanoSecs + (TICK_NSEC-1)) / TICK_NSEC;
# endif
return (cNanoSecs + (TICK_NSEC-1)) / TICK_NSEC;
}
/**
* Starts a sub-timer (RTTimerStart).
*
* @param pSubTimer The sub-timer to start.
* @param u64Now The current timestamp (RTTimeSystemNanoTS()).
* @param u64First The interval from u64Now to the first time the timer should fire.
* @param fPinned true = timer pinned to a specific CPU,
* false = timer can migrate between CPUs
* @param fHighRes Whether the user requested a high resolution timer or not.
* @param enmOldState The old timer state.
*/
static void rtTimerLnxStartSubTimer(PRTTIMERLNXSUBTIMER pSubTimer, uint64_t u64Now, uint64_t u64First,
bool fPinned, bool fHighRes)
{
/*
* Calc when it should start firing.
*/
uint64_t u64NextTS = u64Now + u64First;
if (!fHighRes)
pSubTimer->u.Std.u64NextTS = u64NextTS;
RTTIMERLNX_LOG(("startsubtimer %p\n", pSubTimer->pParent));
pSubTimer->iTick = 0;
#ifdef RTTIMER_LINUX_WITH_HRTIMER
if (fHighRes)
hrtimer_start(&pSubTimer->u.Hr.LnxTimer, rtTimerLnxNanoToKt(u64NextTS),
fPinned ? HRTIMER_MODE_ABS_PINNED : HRTIMER_MODE_ABS);
else
#endif
{
unsigned long cJiffies = !u64First ? 0 : rtTimerLnxNanoToJiffies(u64First);
pSubTimer->u.Std.ulNextJiffies = jiffies + cJiffies;
pSubTimer->u.Std.fFirstAfterChg = true;
#ifdef CONFIG_SMP
if (fPinned)
{
# if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
mod_timer(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
# else
mod_timer_pinned(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
# endif
}
else
#endif
mod_timer(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
}
/* Be a bit careful here since we could be racing the callback. */
if (!rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_ACTIVE, RTTIMERLNXSTATE_STARTING))
rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_ACTIVE, RTTIMERLNXSTATE_MP_STARTING);
}
/**
* Stops a sub-timer (RTTimerStart and rtTimerLinuxMpEvent()).
*
* The caller has already changed the state, so we will not be in a callback
* situation wrt to the calling thread.
*
* @param pSubTimer The sub-timer.
* @param fHighRes Whether the user requested a high resolution timer or not.
*/
static void rtTimerLnxStopSubTimer(PRTTIMERLNXSUBTIMER pSubTimer, bool fHighRes)
{
RTTIMERLNX_LOG(("stopsubtimer %p %d\n", pSubTimer->pParent, fHighRes));
#ifdef RTTIMER_LINUX_WITH_HRTIMER
if (fHighRes)
{
/* There is no equivalent to del_timer in the hrtimer API,
hrtimer_cancel() == del_timer_sync(). Just like the WARN_ON in
del_timer_sync() asserts, waiting for a timer callback to complete
is deadlock prone, so don't do it. */
int rc = hrtimer_try_to_cancel(&pSubTimer->u.Hr.LnxTimer);
if (rc < 0)
{
hrtimer_start(&pSubTimer->u.Hr.LnxTimer, ktime_set(KTIME_SEC_MAX, 0), HRTIMER_MODE_ABS);
hrtimer_try_to_cancel(&pSubTimer->u.Hr.LnxTimer);
}
}
else
#endif
del_timer(&pSubTimer->u.Std.LnxTimer);
rtTimerLnxSetState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED);
}
/**
* Used by RTTimerDestroy and rtTimerLnxCallbackDestroy to do the actual work.
*
* @param pTimer The timer in question.
*/
static void rtTimerLnxDestroyIt(PRTTIMER pTimer)
{
RTSPINLOCK hSpinlock = pTimer->hSpinlock;
RTCPUID iCpu;
Assert(pTimer->fSuspended);
RTTIMERLNX_LOG(("destroyit %p\n", pTimer));
/*
* Remove the MP notifications first because it'll reduce the risk of
* us overtaking any MP event that might theoretically be racing us here.
*/
#ifdef CONFIG_SMP
if ( pTimer->cCpus > 1
&& hSpinlock != NIL_RTSPINLOCK)
{
int rc = RTMpNotificationDeregister(rtTimerLinuxMpEvent, pTimer);
AssertRC(rc);
}
#endif /* CONFIG_SMP */
/*
* Invalidate the handle.
*/
ASMAtomicWriteU32(&pTimer->u32Magic, ~RTTIMER_MAGIC);
/*
* Make sure all timers have stopped executing since we're stopping them in
* an asynchronous manner up in rtTimerLnxStopSubTimer.
*/
iCpu = pTimer->cCpus;
while (iCpu-- > 0)
{
#ifdef RTTIMER_LINUX_WITH_HRTIMER
if (pTimer->fHighRes)
hrtimer_cancel(&pTimer->aSubTimers[iCpu].u.Hr.LnxTimer);
else
#endif
del_timer_sync(&pTimer->aSubTimers[iCpu].u.Std.LnxTimer);
}
/*
* Finally, free the resources.
*/
RTMemFreeEx(pTimer, RT_UOFFSETOF_DYN(RTTIMER, aSubTimers[pTimer->cCpus]));
if (hSpinlock != NIL_RTSPINLOCK)
RTSpinlockDestroy(hSpinlock);
}
/**
* Workqueue callback (no DECLCALLBACK!) for deferred destruction.
*
* @param pWork Pointer to the DtorWorkqueueItem member of our timer
* structure.
*/
static void rtTimerLnxDestroyDeferred(RTR0LNXWORKQUEUEITEM *pWork)
{
PRTTIMER pTimer = RT_FROM_MEMBER(pWork, RTTIMER, DtorWorkqueueItem);
rtTimerLnxDestroyIt(pTimer);
}
/**
* Called when the timer was destroyed by the callback function.
*
* @param pTimer The timer.
* @param pSubTimer The sub-timer which we're handling, the state of this
* will be RTTIMERLNXSTATE_CALLBACK_DESTROYING.
*/
static void rtTimerLnxCallbackDestroy(PRTTIMER pTimer, PRTTIMERLNXSUBTIMER pSubTimer)
{
/*
* If it's an omni timer, the last dude does the destroying.
*/
if (pTimer->cCpus > 1)
{
uint32_t iCpu = pTimer->cCpus;
RTSpinlockAcquire(pTimer->hSpinlock);
Assert(pSubTimer->enmState == RTTIMERLNXSTATE_CB_DESTROYING);
rtTimerLnxSetState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED);
while (iCpu-- > 0)
if (rtTimerLnxGetState(&pTimer->aSubTimers[iCpu].enmState) != RTTIMERLNXSTATE_STOPPED)
{
RTSpinlockRelease(pTimer->hSpinlock);
return;
}
RTSpinlockRelease(pTimer->hSpinlock);
}
/*
* Destroying a timer from the callback is unsafe since the callout code
* might be touching the timer structure upon return (hrtimer does!). So,
* we have to defer the actual destruction to the IRPT workqueue.
*/
rtR0LnxWorkqueuePush(&pTimer->DtorWorkqueueItem, rtTimerLnxDestroyDeferred);
}
#ifdef CONFIG_SMP
/**
* Deal with a sub-timer that has migrated.
*
* @param pTimer The timer.
* @param pSubTimer The sub-timer.
*/
static void rtTimerLnxCallbackHandleMigration(PRTTIMER pTimer, PRTTIMERLNXSUBTIMER pSubTimer)
{
RTTIMERLNXSTATE enmState;
if (pTimer->cCpus > 1)
RTSpinlockAcquire(pTimer->hSpinlock);
do
{
enmState = rtTimerLnxGetState(&pSubTimer->enmState);
switch (enmState)
{
case RTTIMERLNXSTATE_STOPPING:
case RTTIMERLNXSTATE_MP_STOPPING:
enmState = RTTIMERLNXSTATE_STOPPED;
case RTTIMERLNXSTATE_STOPPED:
break;
default:
AssertMsgFailed(("%d\n", enmState)); RT_FALL_THRU();
case RTTIMERLNXSTATE_STARTING:
case RTTIMERLNXSTATE_MP_STARTING:
case RTTIMERLNXSTATE_ACTIVE:
case RTTIMERLNXSTATE_CALLBACK:
case RTTIMERLNXSTATE_CB_STOPPING:
case RTTIMERLNXSTATE_CB_RESTARTING:
if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED, enmState))
enmState = RTTIMERLNXSTATE_STOPPED;
break;
case RTTIMERLNXSTATE_CB_DESTROYING:
{
if (pTimer->cCpus > 1)
RTSpinlockRelease(pTimer->hSpinlock);
rtTimerLnxCallbackDestroy(pTimer, pSubTimer);
return;
}
}
} while (enmState != RTTIMERLNXSTATE_STOPPED);
if (pTimer->cCpus > 1)
RTSpinlockRelease(pTimer->hSpinlock);
}
#endif /* CONFIG_SMP */
/**
* The slow path of rtTimerLnxChangeToCallbackState.
*
* @returns true if changed successfully, false if not.
* @param pSubTimer The sub-timer.
*/
static bool rtTimerLnxChangeToCallbackStateSlow(PRTTIMERLNXSUBTIMER pSubTimer)
{
for (;;)
{
RTTIMERLNXSTATE enmState = rtTimerLnxGetState(&pSubTimer->enmState);
switch (enmState)
{
case RTTIMERLNXSTATE_ACTIVE:
case RTTIMERLNXSTATE_STARTING:
case RTTIMERLNXSTATE_MP_STARTING:
if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_CALLBACK, enmState))
return true;
break;
case RTTIMERLNXSTATE_CALLBACK:
case RTTIMERLNXSTATE_CB_STOPPING:
case RTTIMERLNXSTATE_CB_RESTARTING:
case RTTIMERLNXSTATE_CB_DESTROYING:
AssertMsgFailed(("%d\n", enmState)); RT_FALL_THRU();
default:
return false;
}
ASMNopPause();
}
}
/**
* Tries to change the sub-timer state to 'callback'.
*
* @returns true if changed successfully, false if not.
* @param pSubTimer The sub-timer.
*/
DECLINLINE(bool) rtTimerLnxChangeToCallbackState(PRTTIMERLNXSUBTIMER pSubTimer)
{
if (RT_LIKELY(rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_CALLBACK, RTTIMERLNXSTATE_ACTIVE)))
return true;
return rtTimerLnxChangeToCallbackStateSlow(pSubTimer);
}
#ifdef RTTIMER_LINUX_WITH_HRTIMER
/**
* Timer callback function for high resolution timers.
*
* @returns HRTIMER_NORESTART or HRTIMER_RESTART depending on whether it's a
* one-shot or interval timer.
* @param pHrTimer Pointer to the sub-timer structure.
*/
static enum hrtimer_restart rtTimerLinuxHrCallback(struct hrtimer *pHrTimer)
{
PRTTIMERLNXSUBTIMER pSubTimer = RT_FROM_MEMBER(pHrTimer, RTTIMERLNXSUBTIMER, u.Hr.LnxTimer);
PRTTIMER pTimer = pSubTimer->pParent;
RTTIMERLNX_LOG(("hrcallback %p\n", pTimer));
if (RT_UNLIKELY(!rtTimerLnxChangeToCallbackState(pSubTimer)))
return HRTIMER_NORESTART;
#ifdef CONFIG_SMP
/*
* Check for unwanted migration.
*/
if (pTimer->fAllCpus || pTimer->fSpecificCpu)
{
RTCPUID idCpu = RTMpCpuId();
if (RT_UNLIKELY( pTimer->fAllCpus
? (RTCPUID)(pSubTimer - &pTimer->aSubTimers[0]) != idCpu
: pTimer->idCpu != idCpu))
{
rtTimerLnxCallbackHandleMigration(pTimer, pSubTimer);
return HRTIMER_NORESTART;
}
}
#endif
if (pTimer->u64NanoInterval)
{
/*
* Periodic timer, run it and update the native timer afterwards so
* we can handle RTTimerStop and RTTimerChangeInterval from the
* callback as well as a racing control thread.
*/
pTimer->pfnTimer(pTimer, pTimer->pvUser, ++pSubTimer->iTick);
hrtimer_add_expires_ns(&pSubTimer->u.Hr.LnxTimer, ASMAtomicReadU64(&pTimer->u64NanoInterval));
if (RT_LIKELY(rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_ACTIVE, RTTIMERLNXSTATE_CALLBACK)))
return HRTIMER_RESTART;
}
else
{
/*
* One shot timer (no omni), stop it before dispatching it.
* Allow RTTimerStart as well as RTTimerDestroy to be called from
* the callback.
*/
ASMAtomicWriteBool(&pTimer->fSuspended, true);
pTimer->pfnTimer(pTimer, pTimer->pvUser, ++pSubTimer->iTick);
if (RT_LIKELY(rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED, RTTIMERLNXSTATE_CALLBACK)))
return HRTIMER_NORESTART;
}
/*
* Some state change occurred while we were in the callback routine.
*/
for (;;)
{
RTTIMERLNXSTATE enmState = rtTimerLnxGetState(&pSubTimer->enmState);
switch (enmState)
{
case RTTIMERLNXSTATE_CB_DESTROYING:
rtTimerLnxCallbackDestroy(pTimer, pSubTimer);
return HRTIMER_NORESTART;
case RTTIMERLNXSTATE_CB_STOPPING:
if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED, RTTIMERLNXSTATE_CB_STOPPING))
return HRTIMER_NORESTART;
break;
case RTTIMERLNXSTATE_CB_RESTARTING:
if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_ACTIVE, RTTIMERLNXSTATE_CB_RESTARTING))
{
pSubTimer->iTick = 0;
hrtimer_set_expires(&pSubTimer->u.Hr.LnxTimer, rtTimerLnxNanoToKt(pSubTimer->uNsRestartAt));
return HRTIMER_RESTART;
}
break;
default:
AssertMsgFailed(("%d\n", enmState));
return HRTIMER_NORESTART;
}
ASMNopPause();
}
}
#endif /* RTTIMER_LINUX_WITH_HRTIMER */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
/**
* Timer callback function for standard timers.
*
* @param pLnxTimer Pointer to the Linux timer structure.
*/
static void rtTimerLinuxStdCallback(struct timer_list *pLnxTimer)
{
PRTTIMERLNXSUBTIMER pSubTimer = from_timer(pSubTimer, pLnxTimer, u.Std.LnxTimer);
#else
/**
* Timer callback function for standard timers.
*
* @param ulUser Address of the sub-timer structure.
*/
static void rtTimerLinuxStdCallback(unsigned long ulUser)
{
PRTTIMERLNXSUBTIMER pSubTimer = (PRTTIMERLNXSUBTIMER)ulUser;
#endif
PRTTIMER pTimer = pSubTimer->pParent;
RTTIMERLNX_LOG(("stdcallback %p\n", pTimer));
if (RT_UNLIKELY(!rtTimerLnxChangeToCallbackState(pSubTimer)))
return;
#ifdef CONFIG_SMP
/*
* Check for unwanted migration.
*/
if (pTimer->fAllCpus || pTimer->fSpecificCpu)
{
RTCPUID idCpu = RTMpCpuId();
if (RT_UNLIKELY( pTimer->fAllCpus
? (RTCPUID)(pSubTimer - &pTimer->aSubTimers[0]) != idCpu
: pTimer->idCpu != idCpu))
{
rtTimerLnxCallbackHandleMigration(pTimer, pSubTimer);
return;
}
}
#endif
if (pTimer->u64NanoInterval)
{
/*
* Interval timer, calculate the next timeout.
*
* The first time around, we'll re-adjust the u.Std.u64NextTS to
* try prevent some jittering if we were started at a bad time.
*/
const uint64_t iTick = ++pSubTimer->iTick;
uint64_t u64NanoInterval;
unsigned long cJiffies;
unsigned long flFlags;
spin_lock_irqsave(&pTimer->ChgIntLock, flFlags);
u64NanoInterval = pTimer->u64NanoInterval;
cJiffies = pTimer->cJiffies;
if (RT_UNLIKELY(pSubTimer->u.Std.fFirstAfterChg))
{
pSubTimer->u.Std.fFirstAfterChg = false;
pSubTimer->u.Std.u64NextTS = RTTimeSystemNanoTS();
pSubTimer->u.Std.ulNextJiffies = jiffies;
}
spin_unlock_irqrestore(&pTimer->ChgIntLock, flFlags);
pSubTimer->u.Std.u64NextTS += u64NanoInterval;
if (cJiffies)
{
pSubTimer->u.Std.ulNextJiffies += cJiffies;
/* Prevent overflows when the jiffies counter wraps around.
* Special thanks to Ken Preslan for helping debugging! */
while (time_before(pSubTimer->u.Std.ulNextJiffies, jiffies))
{
pSubTimer->u.Std.ulNextJiffies += cJiffies;
pSubTimer->u.Std.u64NextTS += u64NanoInterval;
}
}
else
{
const uint64_t u64NanoTS = RTTimeSystemNanoTS();
while (pSubTimer->u.Std.u64NextTS < u64NanoTS)
pSubTimer->u.Std.u64NextTS += u64NanoInterval;
pSubTimer->u.Std.ulNextJiffies = jiffies + rtTimerLnxNanoToJiffies(pSubTimer->u.Std.u64NextTS - u64NanoTS);
}
/*
* Run the timer and re-arm it unless the state changed .
* .
* We must re-arm it afterwards as we're not in a position to undo this .
* operation if for instance someone stopped or destroyed us while we .
* were in the callback. (Linux takes care of any races here.)
*/
pTimer->pfnTimer(pTimer, pTimer->pvUser, iTick);
if (RT_LIKELY(rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_ACTIVE, RTTIMERLNXSTATE_CALLBACK)))
{
#ifdef CONFIG_SMP
if (pTimer->fSpecificCpu || pTimer->fAllCpus)
{
# if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
mod_timer(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
# else
mod_timer_pinned(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
# endif
}
else
#endif
mod_timer(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
return;
}
}
else
{
/*
* One shot timer, stop it before dispatching it.
* Allow RTTimerStart as well as RTTimerDestroy to be called from
* the callback.
*/
ASMAtomicWriteBool(&pTimer->fSuspended, true);
pTimer->pfnTimer(pTimer, pTimer->pvUser, ++pSubTimer->iTick);
if (RT_LIKELY(rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED, RTTIMERLNXSTATE_CALLBACK)))
return;
}
/*
* Some state change occurred while we were in the callback routine.
*/
for (;;)
{
RTTIMERLNXSTATE enmState = rtTimerLnxGetState(&pSubTimer->enmState);
switch (enmState)
{
case RTTIMERLNXSTATE_CB_DESTROYING:
rtTimerLnxCallbackDestroy(pTimer, pSubTimer);
return;
case RTTIMERLNXSTATE_CB_STOPPING:
if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED, RTTIMERLNXSTATE_CB_STOPPING))
return;
break;
case RTTIMERLNXSTATE_CB_RESTARTING:
if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_ACTIVE, RTTIMERLNXSTATE_CB_RESTARTING))
{
uint64_t u64NanoTS;
uint64_t u64NextTS;
unsigned long flFlags;
spin_lock_irqsave(&pTimer->ChgIntLock, flFlags);
u64NextTS = pSubTimer->uNsRestartAt;
u64NanoTS = RTTimeSystemNanoTS();
pSubTimer->iTick = 0;
pSubTimer->u.Std.u64NextTS = u64NextTS;
pSubTimer->u.Std.fFirstAfterChg = true;
pSubTimer->u.Std.ulNextJiffies = u64NextTS > u64NanoTS
? jiffies + rtTimerLnxNanoToJiffies(u64NextTS - u64NanoTS)
: jiffies;
spin_unlock_irqrestore(&pTimer->ChgIntLock, flFlags);
#ifdef CONFIG_SMP
if (pTimer->fSpecificCpu || pTimer->fAllCpus)
{
# if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
mod_timer(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
# else
mod_timer_pinned(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
# endif
}
else
#endif
mod_timer(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
return;
}
break;
default:
AssertMsgFailed(("%d\n", enmState));
return;
}
ASMNopPause();
}
}
#ifdef CONFIG_SMP
/**
* Per-cpu callback function (RTMpOnAll/RTMpOnSpecific).
*
* @param idCpu The current CPU.
* @param pvUser1 Pointer to the timer.
* @param pvUser2 Pointer to the argument structure.
*/
static DECLCALLBACK(void) rtTimerLnxStartAllOnCpu(RTCPUID idCpu, void *pvUser1, void *pvUser2)
{
PRTTIMERLINUXSTARTONCPUARGS pArgs = (PRTTIMERLINUXSTARTONCPUARGS)pvUser2;
PRTTIMER pTimer = (PRTTIMER)pvUser1;
Assert(idCpu < pTimer->cCpus);
rtTimerLnxStartSubTimer(&pTimer->aSubTimers[idCpu], pArgs->u64Now, pArgs->u64First, true /*fPinned*/, pTimer->fHighRes);
}
/**
* Worker for RTTimerStart() that takes care of the ugly bits.
*
* @returns RTTimerStart() return value.
* @param pTimer The timer.
* @param pArgs The argument structure.
*/
static int rtTimerLnxOmniStart(PRTTIMER pTimer, PRTTIMERLINUXSTARTONCPUARGS pArgs)
{
RTCPUID iCpu;
RTCPUSET OnlineSet;
RTCPUSET OnlineSet2;
int rc2;
/*
* Prepare all the sub-timers for the startup and then flag the timer
* as a whole as non-suspended, make sure we get them all before
* clearing fSuspended as the MP handler will be waiting on this
* should something happen while we're looping.
*/
RTSpinlockAcquire(pTimer->hSpinlock);
/* Just make it a omni timer restriction that no stop/start races are allowed. */
for (iCpu = 0; iCpu < pTimer->cCpus; iCpu++)
if (rtTimerLnxGetState(&pTimer->aSubTimers[iCpu].enmState) != RTTIMERLNXSTATE_STOPPED)
{
RTSpinlockRelease(pTimer->hSpinlock);
return VERR_TIMER_BUSY;
}
do
{
RTMpGetOnlineSet(&OnlineSet);
for (iCpu = 0; iCpu < pTimer->cCpus; iCpu++)
{
Assert(pTimer->aSubTimers[iCpu].enmState != RTTIMERLNXSTATE_MP_STOPPING);
rtTimerLnxSetState(&pTimer->aSubTimers[iCpu].enmState,
RTCpuSetIsMember(&OnlineSet, iCpu)
? RTTIMERLNXSTATE_STARTING
: RTTIMERLNXSTATE_STOPPED);
}
} while (!RTCpuSetIsEqual(&OnlineSet, RTMpGetOnlineSet(&OnlineSet2)));
ASMAtomicWriteBool(&pTimer->fSuspended, false);
RTSpinlockRelease(pTimer->hSpinlock);
/*
* Start them (can't find any exported function that allows me to
* do this without the cross calls).
*/
pArgs->u64Now = RTTimeSystemNanoTS();
rc2 = RTMpOnAll(rtTimerLnxStartAllOnCpu, pTimer, pArgs);
AssertRC(rc2); /* screw this if it fails. */
/*
* Reset the sub-timers who didn't start up (ALL CPUs case).
*/
RTSpinlockAcquire(pTimer->hSpinlock);
for (iCpu = 0; iCpu < pTimer->cCpus; iCpu++)
if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[iCpu].enmState, RTTIMERLNXSTATE_STOPPED, RTTIMERLNXSTATE_STARTING))
{
/** @todo very odd case for a rainy day. Cpus that temporarily went offline while
* we were between calls needs to nudged as the MP handler will ignore events for
* them because of the STARTING state. This is an extremely unlikely case - not that
* that means anything in my experience... ;-) */
RTTIMERLNX_LOG(("what!? iCpu=%u -> didn't start\n", iCpu));
}
RTSpinlockRelease(pTimer->hSpinlock);
return VINF_SUCCESS;
}
/**
* Worker for RTTimerStop() that takes care of the ugly SMP bits.
*
* @returns true if there was any active callbacks, false if not.
* @param pTimer The timer (valid).
* @param fForDestroy Whether this is for RTTimerDestroy or not.
*/
static bool rtTimerLnxOmniStop(PRTTIMER pTimer, bool fForDestroy)
{
bool fActiveCallbacks = false;
RTCPUID iCpu;
RTTIMERLNXSTATE enmState;
/*
* Mark the timer as suspended and flag all timers as stopping, except
* for those being stopped by an MP event.
*/
RTSpinlockAcquire(pTimer->hSpinlock);
ASMAtomicWriteBool(&pTimer->fSuspended, true);
for (iCpu = 0; iCpu < pTimer->cCpus; iCpu++)
{
for (;;)
{
enmState = rtTimerLnxGetState(&pTimer->aSubTimers[iCpu].enmState);
if ( enmState == RTTIMERLNXSTATE_STOPPED
|| enmState == RTTIMERLNXSTATE_MP_STOPPING)
break;
if ( enmState == RTTIMERLNXSTATE_CALLBACK
|| enmState == RTTIMERLNXSTATE_CB_STOPPING
|| enmState == RTTIMERLNXSTATE_CB_RESTARTING)
{
Assert(enmState != RTTIMERLNXSTATE_CB_STOPPING || fForDestroy);
if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[iCpu].enmState,
!fForDestroy ? RTTIMERLNXSTATE_CB_STOPPING : RTTIMERLNXSTATE_CB_DESTROYING,
enmState))
{
fActiveCallbacks = true;
break;
}
}
else
{
Assert(enmState == RTTIMERLNXSTATE_ACTIVE);
if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[iCpu].enmState, RTTIMERLNXSTATE_STOPPING, enmState))
break;
}
ASMNopPause();
}
}
RTSpinlockRelease(pTimer->hSpinlock);
/*
* Do the actual stopping. Fortunately, this doesn't require any IPIs.
* Unfortunately it cannot be done synchronously.
*/
for (iCpu = 0; iCpu < pTimer->cCpus; iCpu++)
if (rtTimerLnxGetState(&pTimer->aSubTimers[iCpu].enmState) == RTTIMERLNXSTATE_STOPPING)
rtTimerLnxStopSubTimer(&pTimer->aSubTimers[iCpu], pTimer->fHighRes);
return fActiveCallbacks;
}
/**
* Per-cpu callback function (RTMpOnSpecific) used by rtTimerLinuxMpEvent()
* to start a sub-timer on a cpu that just have come online.
*
* @param idCpu The current CPU.
* @param pvUser1 Pointer to the timer.
* @param pvUser2 Pointer to the argument structure.
*/
static DECLCALLBACK(void) rtTimerLinuxMpStartOnCpu(RTCPUID idCpu, void *pvUser1, void *pvUser2)
{
PRTTIMERLINUXSTARTONCPUARGS pArgs = (PRTTIMERLINUXSTARTONCPUARGS)pvUser2;
PRTTIMER pTimer = (PRTTIMER)pvUser1;
RTSPINLOCK hSpinlock;
Assert(idCpu < pTimer->cCpus);
/*
* We have to be kind of careful here as we might be racing RTTimerStop
* (and/or RTTimerDestroy, thus the paranoia.
*/
hSpinlock = pTimer->hSpinlock;
if ( hSpinlock != NIL_RTSPINLOCK
&& pTimer->u32Magic == RTTIMER_MAGIC)
{
RTSpinlockAcquire(hSpinlock);
if ( !ASMAtomicUoReadBool(&pTimer->fSuspended)
&& pTimer->u32Magic == RTTIMER_MAGIC)
{
/* We're sane and the timer is not suspended yet. */
PRTTIMERLNXSUBTIMER pSubTimer = &pTimer->aSubTimers[idCpu];
if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_MP_STARTING, RTTIMERLNXSTATE_STOPPED))
rtTimerLnxStartSubTimer(pSubTimer, pArgs->u64Now, pArgs->u64First, true /*fPinned*/, pTimer->fHighRes);
}
RTSpinlockRelease(hSpinlock);
}
}
/**
* MP event notification callback.
*
* @param enmEvent The event.
* @param idCpu The cpu it applies to.
* @param pvUser The timer.
*/
static DECLCALLBACK(void) rtTimerLinuxMpEvent(RTMPEVENT enmEvent, RTCPUID idCpu, void *pvUser)
{
PRTTIMER pTimer = (PRTTIMER)pvUser;
PRTTIMERLNXSUBTIMER pSubTimer = &pTimer->aSubTimers[idCpu];
RTSPINLOCK hSpinlock;
Assert(idCpu < pTimer->cCpus);
/*
* Some initial paranoia.
*/
if (pTimer->u32Magic != RTTIMER_MAGIC)
return;
hSpinlock = pTimer->hSpinlock;
if (hSpinlock == NIL_RTSPINLOCK)
return;
RTSpinlockAcquire(hSpinlock);
/* Is it active? */
if ( !ASMAtomicUoReadBool(&pTimer->fSuspended)
&& pTimer->u32Magic == RTTIMER_MAGIC)
{
switch (enmEvent)
{
/*
* Try do it without leaving the spin lock, but if we have to, retake it
* when we're on the right cpu.
*/
case RTMPEVENT_ONLINE:
if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_MP_STARTING, RTTIMERLNXSTATE_STOPPED))
{
RTTIMERLINUXSTARTONCPUARGS Args;
Args.u64Now = RTTimeSystemNanoTS();
Args.u64First = 0;
if (RTMpCpuId() == idCpu)
rtTimerLnxStartSubTimer(pSubTimer, Args.u64Now, Args.u64First, true /*fPinned*/, pTimer->fHighRes);
else
{
rtTimerLnxSetState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED); /* we'll recheck it. */
RTSpinlockRelease(hSpinlock);
RTMpOnSpecific(idCpu, rtTimerLinuxMpStartOnCpu, pTimer, &Args);
return; /* we've left the spinlock */
}
}
break;
/*
* The CPU is (going) offline, make sure the sub-timer is stopped.
*
* Linux will migrate it to a different CPU, but we don't want this. The
* timer function is checking for this.
*/
case RTMPEVENT_OFFLINE:
{
RTTIMERLNXSTATE enmState;
while ( (enmState = rtTimerLnxGetState(&pSubTimer->enmState)) == RTTIMERLNXSTATE_ACTIVE
|| enmState == RTTIMERLNXSTATE_CALLBACK
|| enmState == RTTIMERLNXSTATE_CB_RESTARTING)
{
if (enmState == RTTIMERLNXSTATE_ACTIVE)
{
if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_MP_STOPPING, RTTIMERLNXSTATE_ACTIVE))
{
RTSpinlockRelease(hSpinlock);
rtTimerLnxStopSubTimer(pSubTimer, pTimer->fHighRes);
return; /* we've left the spinlock */
}
}
else if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_CB_STOPPING, enmState))
break;
/* State not stable, try again. */
ASMNopPause();
}
break;
}
}
}
RTSpinlockRelease(hSpinlock);
}
#endif /* CONFIG_SMP */
/**
* Callback function use by RTTimerStart via RTMpOnSpecific to start a timer
* running on a specific CPU.
*
* @param idCpu The current CPU.
* @param pvUser1 Pointer to the timer.
* @param pvUser2 Pointer to the argument structure.
*/
static DECLCALLBACK(void) rtTimerLnxStartOnSpecificCpu(RTCPUID idCpu, void *pvUser1, void *pvUser2)
{
PRTTIMERLINUXSTARTONCPUARGS pArgs = (PRTTIMERLINUXSTARTONCPUARGS)pvUser2;
PRTTIMER pTimer = (PRTTIMER)pvUser1;
RT_NOREF_PV(idCpu);
rtTimerLnxStartSubTimer(&pTimer->aSubTimers[0], pArgs->u64Now, pArgs->u64First, true /*fPinned*/, pTimer->fHighRes);
}
RTDECL(int) RTTimerStart(PRTTIMER pTimer, uint64_t u64First)
{
RTTIMERLINUXSTARTONCPUARGS Args;
int rc2;
IPRT_LINUX_SAVE_EFL_AC();
/*
* Validate.
*/
AssertPtrReturn(pTimer, VERR_INVALID_HANDLE);
AssertReturn(pTimer->u32Magic == RTTIMER_MAGIC, VERR_INVALID_HANDLE);
if (!ASMAtomicUoReadBool(&pTimer->fSuspended))
return VERR_TIMER_ACTIVE;
RTTIMERLNX_LOG(("start %p cCpus=%d\n", pTimer, pTimer->cCpus));
Args.u64First = u64First;
#ifdef CONFIG_SMP
/*
* Omni timer?
*/
if (pTimer->fAllCpus)
{
rc2 = rtTimerLnxOmniStart(pTimer, &Args);
IPRT_LINUX_RESTORE_EFL_AC();
return rc2;
}
#endif
/*
* Simple timer - Pretty straight forward if it wasn't for restarting.
*/
Args.u64Now = RTTimeSystemNanoTS();
ASMAtomicWriteU64(&pTimer->aSubTimers[0].uNsRestartAt, Args.u64Now + u64First);
for (;;)
{
RTTIMERLNXSTATE enmState = rtTimerLnxGetState(&pTimer->aSubTimers[0].enmState);
switch (enmState)
{
case RTTIMERLNXSTATE_STOPPED:
if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[0].enmState, RTTIMERLNXSTATE_STARTING, RTTIMERLNXSTATE_STOPPED))
{
ASMAtomicWriteBool(&pTimer->fSuspended, false);
if (!pTimer->fSpecificCpu)
rtTimerLnxStartSubTimer(&pTimer->aSubTimers[0], Args.u64Now, Args.u64First,
false /*fPinned*/, pTimer->fHighRes);
else
{
rc2 = RTMpOnSpecific(pTimer->idCpu, rtTimerLnxStartOnSpecificCpu, pTimer, &Args);
if (RT_FAILURE(rc2))
{
/* Suspend it, the cpu id is probably invalid or offline. */
ASMAtomicWriteBool(&pTimer->fSuspended, true);
rtTimerLnxSetState(&pTimer->aSubTimers[0].enmState, RTTIMERLNXSTATE_STOPPED);
return rc2;
}
}
IPRT_LINUX_RESTORE_EFL_AC();
return VINF_SUCCESS;
}
break;
case RTTIMERLNXSTATE_CALLBACK:
case RTTIMERLNXSTATE_CB_STOPPING:
if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[0].enmState, RTTIMERLNXSTATE_CB_RESTARTING, enmState))
{
ASMAtomicWriteBool(&pTimer->fSuspended, false);
IPRT_LINUX_RESTORE_EFL_AC();
return VINF_SUCCESS;
}
break;
default:
AssertMsgFailed(("%d\n", enmState));
IPRT_LINUX_RESTORE_EFL_AC();
return VERR_INTERNAL_ERROR_4;
}
ASMNopPause();
}
}
RT_EXPORT_SYMBOL(RTTimerStart);
/**
* Common worker for RTTimerStop and RTTimerDestroy.
*
* @returns true if there was any active callbacks, false if not.
* @param pTimer The timer to stop.
* @param fForDestroy Whether it's RTTimerDestroy calling or not.
*/
static bool rtTimerLnxStop(PRTTIMER pTimer, bool fForDestroy)
{
RTTIMERLNX_LOG(("lnxstop %p %d\n", pTimer, fForDestroy));
#ifdef CONFIG_SMP
/*
* Omni timer?
*/
if (pTimer->fAllCpus)
return rtTimerLnxOmniStop(pTimer, fForDestroy);
#endif
/*
* Simple timer.
*/
ASMAtomicWriteBool(&pTimer->fSuspended, true);
for (;;)
{
RTTIMERLNXSTATE enmState = rtTimerLnxGetState(&pTimer->aSubTimers[0].enmState);
switch (enmState)
{
case RTTIMERLNXSTATE_ACTIVE:
if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[0].enmState, RTTIMERLNXSTATE_STOPPING, RTTIMERLNXSTATE_ACTIVE))
{
rtTimerLnxStopSubTimer(&pTimer->aSubTimers[0], pTimer->fHighRes);
return false;
}
break;
case RTTIMERLNXSTATE_CALLBACK:
case RTTIMERLNXSTATE_CB_RESTARTING:
case RTTIMERLNXSTATE_CB_STOPPING:
Assert(enmState != RTTIMERLNXSTATE_CB_STOPPING || fForDestroy);
if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[0].enmState,
!fForDestroy ? RTTIMERLNXSTATE_CB_STOPPING : RTTIMERLNXSTATE_CB_DESTROYING,
enmState))
return true;
break;
case RTTIMERLNXSTATE_STOPPED:
return VINF_SUCCESS;
case RTTIMERLNXSTATE_CB_DESTROYING:
AssertMsgFailed(("enmState=%d pTimer=%p\n", enmState, pTimer));
return true;
default:
case RTTIMERLNXSTATE_STARTING:
case RTTIMERLNXSTATE_MP_STARTING:
case RTTIMERLNXSTATE_STOPPING:
case RTTIMERLNXSTATE_MP_STOPPING:
AssertMsgFailed(("enmState=%d pTimer=%p\n", enmState, pTimer));
return false;
}
/* State not stable, try again. */
ASMNopPause();
}
}
RTDECL(int) RTTimerStop(PRTTIMER pTimer)
{
/*
* Validate.
*/
IPRT_LINUX_SAVE_EFL_AC();
AssertPtrReturn(pTimer, VERR_INVALID_HANDLE);
AssertReturn(pTimer->u32Magic == RTTIMER_MAGIC, VERR_INVALID_HANDLE);
RTTIMERLNX_LOG(("stop %p\n", pTimer));
if (ASMAtomicUoReadBool(&pTimer->fSuspended))
return VERR_TIMER_SUSPENDED;
rtTimerLnxStop(pTimer, false /*fForDestroy*/);
IPRT_LINUX_RESTORE_EFL_AC();
return VINF_SUCCESS;
}
RT_EXPORT_SYMBOL(RTTimerStop);
RTDECL(int) RTTimerChangeInterval(PRTTIMER pTimer, uint64_t u64NanoInterval)
{
unsigned long cJiffies;
unsigned long flFlags;
IPRT_LINUX_SAVE_EFL_AC();
/*
* Validate.
*/
AssertPtrReturn(pTimer, VERR_INVALID_HANDLE);
AssertReturn(pTimer->u32Magic == RTTIMER_MAGIC, VERR_INVALID_HANDLE);
AssertReturn(u64NanoInterval, VERR_INVALID_PARAMETER);
AssertReturn(u64NanoInterval < UINT64_MAX / 8, VERR_INVALID_PARAMETER);
AssertReturn(pTimer->u64NanoInterval, VERR_INVALID_STATE);
RTTIMERLNX_LOG(("change %p %llu\n", pTimer, u64NanoInterval));
#ifdef RTTIMER_LINUX_WITH_HRTIMER
/*
* For the high resolution timers it is easy since we don't care so much
* about when it is applied to the sub-timers.
*/
if (pTimer->fHighRes)
{
ASMAtomicWriteU64(&pTimer->u64NanoInterval, u64NanoInterval);
IPRT_LINUX_RESTORE_EFL_AC();
return VINF_SUCCESS;
}
#endif
/*
* Standard timers have a bit more complicated way of calculating
* their interval and such. So, forget omni timers for now.
*/
if (pTimer->cCpus > 1)
return VERR_NOT_SUPPORTED;
cJiffies = u64NanoInterval / RTTimerGetSystemGranularity();
if (cJiffies * RTTimerGetSystemGranularity() != u64NanoInterval)
cJiffies = 0;
spin_lock_irqsave(&pTimer->ChgIntLock, flFlags);
pTimer->aSubTimers[0].u.Std.fFirstAfterChg = true;
pTimer->cJiffies = cJiffies;
ASMAtomicWriteU64(&pTimer->u64NanoInterval, u64NanoInterval);
spin_unlock_irqrestore(&pTimer->ChgIntLock, flFlags);
IPRT_LINUX_RESTORE_EFL_AC();
return VINF_SUCCESS;
}
RT_EXPORT_SYMBOL(RTTimerChangeInterval);
RTDECL(int) RTTimerDestroy(PRTTIMER pTimer)
{
bool fCanDestroy;
IPRT_LINUX_SAVE_EFL_AC();
/*
* Validate. It's ok to pass NULL pointer.
*/
if (pTimer == /*NIL_RTTIMER*/ NULL)
return VINF_SUCCESS;
AssertPtrReturn(pTimer, VERR_INVALID_HANDLE);
AssertReturn(pTimer->u32Magic == RTTIMER_MAGIC, VERR_INVALID_HANDLE);
RTTIMERLNX_LOG(("destroy %p\n", pTimer));
/** @todo We should invalidate the magic here! */
/*
* Stop the timer if it's still active, then destroy it if we can.
*/
if (!ASMAtomicUoReadBool(&pTimer->fSuspended))
fCanDestroy = rtTimerLnxStop(pTimer, true /*fForDestroy*/);
else
{
uint32_t iCpu = pTimer->cCpus;
if (pTimer->cCpus > 1)
RTSpinlockAcquire(pTimer->hSpinlock);
fCanDestroy = true;
while (iCpu-- > 0)
{
for (;;)
{
RTTIMERLNXSTATE enmState = rtTimerLnxGetState(&pTimer->aSubTimers[iCpu].enmState);
switch (enmState)
{
case RTTIMERLNXSTATE_CALLBACK:
case RTTIMERLNXSTATE_CB_RESTARTING:
case RTTIMERLNXSTATE_CB_STOPPING:
if (!rtTimerLnxCmpXchgState(&pTimer->aSubTimers[iCpu].enmState, RTTIMERLNXSTATE_CB_DESTROYING, enmState))
continue;
fCanDestroy = false;
break;
case RTTIMERLNXSTATE_CB_DESTROYING:
AssertMsgFailed(("%d\n", enmState));
fCanDestroy = false;
break;
default:
break;
}
break;
}
}
if (pTimer->cCpus > 1)
RTSpinlockRelease(pTimer->hSpinlock);
}
if (fCanDestroy)
{
/* For paranoid reasons, defer actually destroying the semaphore when
in atomic or interrupt context. */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 32)
if (in_atomic() || in_interrupt())
#else
if (in_interrupt())
#endif
rtR0LnxWorkqueuePush(&pTimer->DtorWorkqueueItem, rtTimerLnxDestroyDeferred);
else
rtTimerLnxDestroyIt(pTimer);
}
IPRT_LINUX_RESTORE_EFL_AC();
return VINF_SUCCESS;
}
RT_EXPORT_SYMBOL(RTTimerDestroy);
RTDECL(int) RTTimerCreateEx(PRTTIMER *ppTimer, uint64_t u64NanoInterval, uint32_t fFlags, PFNRTTIMER pfnTimer, void *pvUser)
{
PRTTIMER pTimer;
RTCPUID iCpu;
unsigned cCpus;
int rc;
IPRT_LINUX_SAVE_EFL_AC();
rtR0LnxWorkqueueFlush(); /* for 2.4 */
*ppTimer = NULL;
/*
* Validate flags.
*/
if (!RTTIMER_FLAGS_ARE_VALID(fFlags))
{
IPRT_LINUX_RESTORE_EFL_AC();
return VERR_INVALID_PARAMETER;
}
if ( (fFlags & RTTIMER_FLAGS_CPU_SPECIFIC)
&& (fFlags & RTTIMER_FLAGS_CPU_ALL) != RTTIMER_FLAGS_CPU_ALL
&& !RTMpIsCpuPossible(RTMpCpuIdFromSetIndex(fFlags & RTTIMER_FLAGS_CPU_MASK)))
{
IPRT_LINUX_RESTORE_EFL_AC();
return VERR_CPU_NOT_FOUND;
}
/*
* Allocate the timer handler.
*/
cCpus = 1;
#ifdef CONFIG_SMP
if ((fFlags & RTTIMER_FLAGS_CPU_ALL) == RTTIMER_FLAGS_CPU_ALL)
{
cCpus = RTMpGetMaxCpuId() + 1;
Assert(cCpus <= RTCPUSET_MAX_CPUS); /* On linux we have a 1:1 relationship between cpuid and set index. */
AssertReturnStmt(u64NanoInterval, IPRT_LINUX_RESTORE_EFL_AC(), VERR_NOT_IMPLEMENTED); /* We don't implement single shot on all cpus, sorry. */
}
#endif
rc = RTMemAllocEx(RT_UOFFSETOF_DYN(RTTIMER, aSubTimers[cCpus]), 0,
RTMEMALLOCEX_FLAGS_ZEROED | RTMEMALLOCEX_FLAGS_ANY_CTX_FREE, (void **)&pTimer);
if (RT_FAILURE(rc))
{
IPRT_LINUX_RESTORE_EFL_AC();
return rc;
}
/*
* Initialize it.
*/
pTimer->u32Magic = RTTIMER_MAGIC;
pTimer->hSpinlock = NIL_RTSPINLOCK;
pTimer->fSuspended = true;
pTimer->fHighRes = !!(fFlags & RTTIMER_FLAGS_HIGH_RES);
#ifdef CONFIG_SMP
pTimer->fSpecificCpu = (fFlags & RTTIMER_FLAGS_CPU_SPECIFIC) && (fFlags & RTTIMER_FLAGS_CPU_ALL) != RTTIMER_FLAGS_CPU_ALL;
pTimer->fAllCpus = (fFlags & RTTIMER_FLAGS_CPU_ALL) == RTTIMER_FLAGS_CPU_ALL;
pTimer->idCpu = pTimer->fSpecificCpu
? RTMpCpuIdFromSetIndex(fFlags & RTTIMER_FLAGS_CPU_MASK)
: NIL_RTCPUID;
#else
pTimer->fSpecificCpu = !!(fFlags & RTTIMER_FLAGS_CPU_SPECIFIC);
pTimer->idCpu = RTMpCpuId();
#endif
pTimer->cCpus = cCpus;
pTimer->pfnTimer = pfnTimer;
pTimer->pvUser = pvUser;
pTimer->u64NanoInterval = u64NanoInterval;
pTimer->cJiffies = u64NanoInterval / RTTimerGetSystemGranularity();
if (pTimer->cJiffies * RTTimerGetSystemGranularity() != u64NanoInterval)
pTimer->cJiffies = 0;
spin_lock_init(&pTimer->ChgIntLock);
for (iCpu = 0; iCpu < cCpus; iCpu++)
{
#ifdef RTTIMER_LINUX_WITH_HRTIMER
if (pTimer->fHighRes)
{
hrtimer_init(&pTimer->aSubTimers[iCpu].u.Hr.LnxTimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
pTimer->aSubTimers[iCpu].u.Hr.LnxTimer.function = rtTimerLinuxHrCallback;
}
else
#endif
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
timer_setup(&pTimer->aSubTimers[iCpu].u.Std.LnxTimer, rtTimerLinuxStdCallback, TIMER_PINNED);
#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
init_timer_pinned(&pTimer->aSubTimers[iCpu].u.Std.LnxTimer);
#else
init_timer(&pTimer->aSubTimers[iCpu].u.Std.LnxTimer);
#endif
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
pTimer->aSubTimers[iCpu].u.Std.LnxTimer.data = (unsigned long)&pTimer->aSubTimers[iCpu];
pTimer->aSubTimers[iCpu].u.Std.LnxTimer.function = rtTimerLinuxStdCallback;
#endif
pTimer->aSubTimers[iCpu].u.Std.LnxTimer.expires = jiffies;
pTimer->aSubTimers[iCpu].u.Std.u64NextTS = 0;
}
pTimer->aSubTimers[iCpu].iTick = 0;
pTimer->aSubTimers[iCpu].pParent = pTimer;
pTimer->aSubTimers[iCpu].enmState = RTTIMERLNXSTATE_STOPPED;
}
#ifdef CONFIG_SMP
/*
* If this is running on ALL cpus, we'll have to register a callback
* for MP events (so timers can be started/stopped on cpus going
* online/offline). We also create the spinlock for synchronizing
* stop/start/mp-event.
*/
if (cCpus > 1)
{
int rc = RTSpinlockCreate(&pTimer->hSpinlock, RTSPINLOCK_FLAGS_INTERRUPT_SAFE, "RTTimerLnx");
if (RT_SUCCESS(rc))
rc = RTMpNotificationRegister(rtTimerLinuxMpEvent, pTimer);
else
pTimer->hSpinlock = NIL_RTSPINLOCK;
if (RT_FAILURE(rc))
{
RTTimerDestroy(pTimer);
IPRT_LINUX_RESTORE_EFL_AC();
return rc;
}
}
#endif /* CONFIG_SMP */
RTTIMERLNX_LOG(("create %p hires=%d fFlags=%#x cCpus=%u\n", pTimer, pTimer->fHighRes, fFlags, cCpus));
*ppTimer = pTimer;
IPRT_LINUX_RESTORE_EFL_AC();
return VINF_SUCCESS;
}
RT_EXPORT_SYMBOL(RTTimerCreateEx);
RTDECL(uint32_t) RTTimerGetSystemGranularity(void)
{
#if 0 /** @todo Not sure if this is what we want or not... Add new API for
* querying the resolution of the high res timers? */
struct timespec Ts;
int rc;
IPRT_LINUX_SAVE_EFL_AC();
rc = hrtimer_get_res(CLOCK_MONOTONIC, &Ts);
IPRT_LINUX_RESTORE_EFL_AC();
if (!rc)
{
Assert(!Ts.tv_sec);
return Ts.tv_nsec;
}
#endif
return RT_NS_1SEC / HZ; /* ns */
}
RT_EXPORT_SYMBOL(RTTimerGetSystemGranularity);
RTDECL(int) RTTimerRequestSystemGranularity(uint32_t u32Request, uint32_t *pu32Granted)
{
RT_NOREF_PV(u32Request); RT_NOREF_PV(*pu32Granted);
return VERR_NOT_SUPPORTED;
}
RT_EXPORT_SYMBOL(RTTimerRequestSystemGranularity);
RTDECL(int) RTTimerReleaseSystemGranularity(uint32_t u32Granted)
{
RT_NOREF_PV(u32Granted);
return VERR_NOT_SUPPORTED;
}
RT_EXPORT_SYMBOL(RTTimerReleaseSystemGranularity);
RTDECL(bool) RTTimerCanDoHighResolution(void)
{
#ifdef RTTIMER_LINUX_WITH_HRTIMER
return true;
#else
return false;
#endif
}
RT_EXPORT_SYMBOL(RTTimerCanDoHighResolution);
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