timer-r0drv-linux.c@ 32670

Last change on this file since 32670 was 32670, checked in by vboxsync, 14 years ago
timer-r0drv-linux.c: bug fixes. The ugly guest debugging tracking will be removed when fully debugged.
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 51.4 KB

Line
1	/* $Id: timer-r0drv-linux.c 32670 2010-09-21 16:21:55Z vboxsync $ */
2	/** @file
3	* IPRT - Timers, Ring-0 Driver, Linux.
4	*/
5
6	/*
7	* Copyright (C) 2006-2010 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*
17	* The contents of this file may alternatively be used under the terms
18	* of the Common Development and Distribution License Version 1.0
19	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20	* VirtualBox OSE distribution, in which case the provisions of the
21	* CDDL are applicable instead of those of the GPL.
22	*
23	* You may elect to license modified versions of this file under the
24	* terms and conditions of either the GPL or the CDDL or both.
25	*/
26
27
28	/*******************************************************************************
29	* Header Files *
30	*******************************************************************************/
31	#include "the-linux-kernel.h"
32	#include "internal/iprt.h"
33
34	#include <iprt/timer.h>
35	#include <iprt/time.h>
36	#include <iprt/mp.h>
37	#include <iprt/cpuset.h>
38	#include <iprt/spinlock.h>
39	#include <iprt/err.h>
40	#include <iprt/asm.h>
41	#include <iprt/assert.h>
42	#include <iprt/alloc.h>
43
44	#include "internal/magics.h"
45
46	/** @def RTTIMER_LINUX_HAVE_HRTIMER
47	* Whether the kernel support high resolution timers (Linux kernel versions
48	* 2.6.28 and later (hrtimer_add_expires_ns()). */
49	#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 28)
50	# define RTTIMER_LINUX_HAVE_HRTIMER
51	#endif
52
53	/** @def RTTIMER_LINUX_WITH_HRTIMER
54	* Whether to use high resolution timers. */
55	#if !defined(RTTIMER_LINUX_WITH_HRTIMER) \
56	&& defined(RTTIMER_LINUX_HAVE_HRTIMER)
57	# define RTTIMER_LINUX_WITH_HRTIMER
58	#endif
59
60	#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 31)
61	# define mod_timer_pinned mod_timer
62	# define HRTIMER_MODE_ABS_PINNED HRTIMER_MODE_ABS
63	#endif
64
65
66	/*******************************************************************************
67	* Structures and Typedefs *
68	*******************************************************************************/
69	/**
70	* Timer state machine.
71	*
72	* This is used to try handle the issues with MP events and
73	* timers that runs on all CPUs. It's relatively nasty :-/
74	*/
75	typedef enum RTTIMERLNXSTATE
76	{
77	/** Stopped. */
78	RTTIMERLNXSTATE_STOPPED = 0,
79	/** Transient state; next ACTIVE. */
80	RTTIMERLNXSTATE_STARTING,
81	/** Transient state; next ACTIVE. (not really necessary) */
82	RTTIMERLNXSTATE_MP_STARTING,
83	/** Active. */
84	RTTIMERLNXSTATE_ACTIVE,
85	/** Active and in callback; next ACTIVE, STOPPED or CALLBACK_DESTROYING. */
86	RTTIMERLNXSTATE_CALLBACK,
87	/** Stopped while in the callback; next STOPPED. */
88	RTTIMERLNXSTATE_CB_STOPPING,
89	/** Restarted while in the callback; next ACTIVE, STOPPED, DESTROYING. */
90	RTTIMERLNXSTATE_CB_RESTARTING,
91	/** The callback shall destroy the timer; next STOPPED. */
92	RTTIMERLNXSTATE_CB_DESTROYING,
93	/** Transient state; next STOPPED. */
94	RTTIMERLNXSTATE_STOPPING,
95	/** Transient state; next STOPPED. */
96	RTTIMERLNXSTATE_MP_STOPPING,
97	/** The usual 32-bit hack. */
98	RTTIMERLNXSTATE_32BIT_HACK = 0x7fffffff
99	} RTTIMERLNXSTATE;
100
101
102	/**
103	* A Linux sub-timer.
104	*/
105	typedef struct RTTIMERLNXSUBTIMER
106	{
107	/** Timer specific data. */
108	union
109	{
110	#if defined(RTTIMER_LINUX_WITH_HRTIMER)
111	/** High resolution timer. */
112	struct
113	{
114	/** The linux timer structure. */
115	struct hrtimer LnxTimer;
116	} Hr;
117	#endif
118	/** Standard timer. */
119	struct
120	{
121	/** The linux timer structure. */
122	struct timer_list LnxTimer;
123	/** The start of the current run (ns).
124	* This is used to calculate when the timer ought to fire the next time. */
125	uint64_t u64StartTS;
126	/** The start of the current run (ns).
127	* This is used to calculate when the timer ought to fire the next time. */
128	uint64_t u64NextTS;
129	/** The u64NextTS in jiffies. */
130	unsigned long ulNextJiffies;
131	} Std;
132	} u;
133	/** The current tick number (since u.Std.u64StartTS). */
134	uint64_t iTick;
135	/** Restart the single shot timer at this specific time.
136	* Used when a single shot timer is restarted from the callback. */
137	uint64_t volatile uNsRestartAt;
138	/** Pointer to the parent timer. */
139	PRTTIMER pParent;
140	/** The current sub-timer state. */
141	RTTIMERLNXSTATE volatile enmState;
142	} RTTIMERLNXSUBTIMER;
143	/** Pointer to a linux sub-timer. */
144	typedef RTTIMERLNXSUBTIMER *PRTTIMERLNXSUBTIMER;
145
146
147	/**
148	* The internal representation of an Linux timer handle.
149	*/
150	typedef struct RTTIMER
151	{
152	/** Magic.
153	* This is RTTIMER_MAGIC, but changes to something else before the timer
154	* is destroyed to indicate clearly that thread should exit. */
155	uint32_t volatile u32Magic;
156	/** Spinlock synchronizing the fSuspended and MP event handling.
157	* This is NIL_RTSPINLOCK if cCpus == 1. */
158	RTSPINLOCK hSpinlock;
159	/** Flag indicating that the timer is suspended. */
160	bool volatile fSuspended;
161	/** Whether the timer must run on one specific CPU or not. */
162	bool fSpecificCpu;
163	#ifdef CONFIG_SMP
164	/** Whether the timer must run on all CPUs or not. */
165	bool fAllCpus;
166	#endif /* else: All -> specific on non-SMP kernels */
167	/** Whether it is a high resolution timer or a standard one. */
168	bool fHighRes;
169	/** The id of the CPU it must run on if fSpecificCpu is set. */
170	RTCPUID idCpu;
171	/** The number of CPUs this timer should run on. */
172	RTCPUID cCpus;
173	/** Callback. */
174	PFNRTTIMER pfnTimer;
175	/** User argument. */
176	void *pvUser;
177	/** The timer interval. 0 if one-shot. */
178	uint64_t volatile u64NanoInterval;
179	/** This is set to the number of jiffies between ticks if the interval is
180	* an exact number of jiffies. (Standard timers only.) */
181	unsigned long cJiffies;
182	/** Sub-timers.
183	* Normally there is just one, but for RTTIMER_FLAGS_CPU_ALL this will contain
184	* an entry for all possible cpus. In that case the index will be the same as
185	* for the RTCpuSet. */
186	RTTIMERLNXSUBTIMER aSubTimers[1];
187	} RTTIMER;
188
189
190	/**
191	* A rtTimerLinuxStartOnCpu and rtTimerLinuxStartOnCpu argument package.
192	*/
193	typedef struct RTTIMERLINUXSTARTONCPUARGS
194	{
195	/** The current time (RTTimeNanoTS). */
196	uint64_t u64Now;
197	/** When to start firing (delta). */
198	uint64_t u64First;
199	} RTTIMERLINUXSTARTONCPUARGS;
200	/** Pointer to a rtTimerLinuxStartOnCpu argument package. */
201	typedef RTTIMERLINUXSTARTONCPUARGS *PRTTIMERLINUXSTARTONCPUARGS;
202
203
204	/*******************************************************************************
205	* Internal Functions *
206	*******************************************************************************/
207	#ifdef CONFIG_SMP
208	static DECLCALLBACK(void) rtTimerLinuxMpEvent(RTMPEVENT enmEvent, RTCPUID idCpu, void *pvUser);
209	#endif
210
211	#if 0
212	#define DEBUG_HACKING
213	#include <iprt/string.h>
214	#include <iprt/asm-amd64-x86.h>
215	static void myLogBackdoorPrintf(const char *pszFormat, ...)
216	{
217	char szTmp[256];
218	va_list args;
219	size_t cb;
220
221	cb = RTStrPrintf(szTmp, sizeof(szTmp) - 10, "%d: ", RTMpCpuId());
222	va_start(args, pszFormat);
223	cb += RTStrPrintfV(&szTmp[cb], sizeof(szTmp) - cb, pszFormat, args);
224	va_end(args);
225
226	ASMOutStrU8(0x504, (uint8_t *)&szTmp[0], cb);
227	}
228	#define RTAssertMsg1Weak(pszExpr, uLine, pszFile, pszFunction) \
229	myLogBackdoorPrintf("\n!!Guest Assertion failed!!\n%s(%d) %s\n%s\n", uLine, pszFile, pszFunction, (pszExpr))
230	#define RTAssertMsg2Weak myLogBackdoorPrintf
231	#define dprintf(a) myLogBackdoorPrintf a
232	#else
233	#define dprintf(a) do { } while (0)
234	#endif
235
236	/**
237	* Sets the state.
238	*/
239	DECLINLINE(void) rtTimerLnxSetState(RTTIMERLNXSTATE volatile *penmState, RTTIMERLNXSTATE enmNewState)
240	{
241	#ifdef DEBUG_HACKING
242	dprintf(("set %d -> %d\n", *penmState, enmNewState));
243	#endif
244	ASMAtomicWriteU32((uint32_t volatile *)penmState, enmNewState);
245	}
246
247
248	/**
249	* Sets the state if it has a certain value.
250	*
251	* @return true if xchg was done.
252	* @return false if xchg wasn't done.
253	*/
254	#ifdef DEBUG_HACKING
255	#define rtTimerLnxCmpXchgState(penmState, enmNewState, enmCurState) rtTimerLnxCmpXchgStateDebug(penmState, enmNewState, enmCurState, __LINE__)
256	static bool rtTimerLnxCmpXchgStateDebug(RTTIMERLNXSTATE volatile *penmState, RTTIMERLNXSTATE enmNewState,
257	RTTIMERLNXSTATE enmCurState, uint32_t uLine)
258	{
259	RTTIMERLNXSTATE enmOldState = enmCurState;
260	bool fRc = ASMAtomicCmpXchgExU32((uint32_t volatile )penmState, enmNewState, enmCurState, (uint32_t )&enmOldState);
261	dprintf(("cxg %d -> %d - %d at %u\n", enmOldState, enmNewState, fRc, uLine));
262	return fRc;
263	}
264	#else
265	DECLINLINE(bool) rtTimerLnxCmpXchgState(RTTIMERLNXSTATE volatile *penmState, RTTIMERLNXSTATE enmNewState,
266	RTTIMERLNXSTATE enmCurState)
267	{
268	return ASMAtomicCmpXchgU32((uint32_t volatile *)penmState, enmNewState, enmCurState);
269	}
270	#endif
271
272
273	/**
274	* Gets the state.
275	*/
276	DECLINLINE(RTTIMERLNXSTATE) rtTimerLnxGetState(RTTIMERLNXSTATE volatile *penmState)
277	{
278	return (RTTIMERLNXSTATE)ASMAtomicUoReadU32((uint32_t volatile *)penmState);
279	}
280
281	#ifdef RTTIMER_LINUX_WITH_HRTIMER
282
283	/**
284	* Converts a nano second time stamp to ktime_t.
285	*
286	* ASSUMES RTTimeNanoTS() is implemented using ktime_get_ts().
287	*
288	* @returns ktime_t.
289	* @param cNanoSecs Nanoseconds.
290	*/
291	DECLINLINE(ktime_t) rtTimerLnxNanoToKt(uint64_t cNanoSecs)
292	{
293	/* With some luck the compiler optimizes the division out of this... (Bet it doesn't.) */
294	return ktime_set(cNanoSecs / 1000000000, cNanoSecs % 1000000000);
295	}
296
297	/**
298	* Converts ktime_t to a nano second time stamp.
299	*
300	* ASSUMES RTTimeNanoTS() is implemented using ktime_get_ts().
301	*
302	* @returns nano second time stamp.
303	* @param Kt ktime_t.
304	*/
305	DECLINLINE(uint64_t) rtTimerLnxKtToNano(ktime_t Kt)
306	{
307	return ktime_to_ns(Kt);
308	}
309
310	#endif /* RTTIMER_LINUX_WITH_HRTIMER */
311
312	/**
313	* Converts a nano second interval to jiffies.
314	*
315	* @returns Jiffies.
316	* @param cNanoSecs Nanoseconds.
317	*/
318	DECLINLINE(unsigned long) rtTimerLnxNanoToJiffies(uint64_t cNanoSecs)
319	{
320	/* this can be made even better... */
321	if (cNanoSecs > (uint64_t)TICK_NSEC * MAX_JIFFY_OFFSET)
322	return MAX_JIFFY_OFFSET;
323	# if ARCH_BITS == 32
324	if (RT_LIKELY(cNanoSecs <= UINT32_MAX))
325	return ((uint32_t)cNanoSecs + (TICK_NSEC-1)) / TICK_NSEC;
326	# endif
327	return (cNanoSecs + (TICK_NSEC-1)) / TICK_NSEC;
328	}
329
330
331	/**
332	* Starts a sub-timer (RTTimerStart).
333	*
334	* @param pSubTimer The sub-timer to start.
335	* @param u64Now The current timestamp (RTTimeNanoTS()).
336	* @param u64First The interval from u64Now to the first time the timer should fire.
337	* @param fPinned true = timer pinned to a specific CPU,
338	* false = timer can migrate between CPUs
339	* @param fHighRes Whether the user requested a high resolution timer or not.
340	* @param enmOldState The old timer state.
341	*/
342	static void rtTimerLnxStartSubTimer(PRTTIMERLNXSUBTIMER pSubTimer, uint64_t u64Now, uint64_t u64First,
343	bool fPinned, bool fHighRes)
344	{
345	/*
346	* Calc when it should start firing.
347	*/
348	uint64_t u64NextTS = u64Now + u64First;
349	if (fHighRes)
350	{
351	pSubTimer->u.Std.u64StartTS = u64NextTS;
352	pSubTimer->u.Std.u64NextTS = u64NextTS;
353	}
354	dprintf(("startsubtimer %p\n", pSubTimer->pParent));
355
356	pSubTimer->iTick = 0;
357
358	#ifdef RTTIMER_LINUX_WITH_HRTIMER
359	if (fHighRes)
360	hrtimer_start(&pSubTimer->u.Hr.LnxTimer, rtTimerLnxNanoToKt(u64NextTS),
361	fPinned ? HRTIMER_MODE_ABS_PINNED : HRTIMER_MODE_ABS);
362	else
363	#endif
364	{
365	unsigned long cJiffies = !u64First ? 0 : rtTimerLnxNanoToJiffies(u64First);
366	pSubTimer->u.Std.ulNextJiffies = jiffies + cJiffies;
367	#ifdef CONFIG_SMP
368	if (fPinned)
369	mod_timer_pinned(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
370	else
371	#endif
372	mod_timer(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
373	}
374
375	/* Be a bit careful here since we could be racing the callback. */
376	if (!rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_ACTIVE, RTTIMERLNXSTATE_STARTING))
377	rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_ACTIVE, RTTIMERLNXSTATE_MP_STARTING);
378	}
379
380
381	/**
382	* Stops a sub-timer (RTTimerStart and rtTimerLinuxMpEvent()).
383	*
384	* The caller has already changed the state, so we will not be in a callback
385	* situation wrt to the calling thread.
386	*
387	* @param pSubTimer The sub-timer.
388	* @param fHighRes Whether the user requested a high resolution timer or not.
389	*/
390	static void rtTimerLnxStopSubTimer(PRTTIMERLNXSUBTIMER pSubTimer, bool fHighRes)
391	{
392	dprintf(("stopsubtimer %p %d\n", pSubTimer->pParent, fHighRes));
393	#ifdef RTTIMER_LINUX_WITH_HRTIMER
394	if (fHighRes)
395	hrtimer_cancel(&pSubTimer->u.Hr.LnxTimer);
396	else
397	#endif
398	{
399	if (timer_pending(&pSubTimer->u.Std.LnxTimer))
400	del_timer_sync(&pSubTimer->u.Std.LnxTimer);
401	}
402
403	rtTimerLnxSetState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED);
404	}
405
406
407	/**
408	* Used by RTTimerDestroy and rtTimerLnxCallbackDestroy to do the actual work.
409	*
410	* @param pTimer The timer in question.
411	*/
412	static void rtTimerLnxDestroyIt(PRTTIMER pTimer)
413	{
414	RTSPINLOCK hSpinlock = pTimer->hSpinlock;
415	Assert(pTimer->fSuspended);
416	dprintf(("destroyit %p\n", pTimer));
417
418	/*
419	* Remove the MP notifications first because it'll reduce the risk of
420	* us overtaking any MP event that might theoretically be racing us here.
421	*/
422	#ifdef CONFIG_SMP
423	if ( pTimer->cCpus > 1
424	&& hSpinlock != NIL_RTSPINLOCK)
425	{
426	int rc = RTMpNotificationDeregister(rtTimerLinuxMpEvent, pTimer);
427	AssertRC(rc);
428	}
429	#endif /* CONFIG_SMP */
430
431	/*
432	* Uninitialize the structure and free the associated resources.
433	* The spinlock goes last.
434	*/
435	ASMAtomicWriteU32(&pTimer->u32Magic, ~RTTIMER_MAGIC);
436	#if 0 /fixme/
437	rtR0MemFreeNoCtxCheck(pTimer);
438	#else
439	RTMemFree(pTimer);
440	#endif
441	if (hSpinlock != NIL_RTSPINLOCK)
442	RTSpinlockDestroy(hSpinlock);
443	}
444
445
446	/**
447	* Called when the timer was destroyed by the callback function.
448	*
449	* @param pTimer The timer.
450	* @param pSubTimer The sub-timer which we're handling, the state of this
451	* will be RTTIMERLNXSTATE_CALLBACK_DESTROYING.
452	*/
453	static void rtTimerLnxCallbackDestroy(PRTTIMER pTimer, PRTTIMERLNXSUBTIMER pSubTimer)
454	{
455	/*
456	* If it's an omni timer, the last dude does the destroying.
457	*/
458	if (pTimer->cCpus > 1)
459	{
460	bool fAllStopped = true;
461	uint32_t iCpu = pTimer->cCpus;
462	RTSPINLOCKTMP Tmp = RTSPINLOCKTMP_INITIALIZER;
463	RTSpinlockAcquire(pTimer->hSpinlock, &Tmp);
464
465	Assert(pSubTimer->enmState == RTTIMERLNXSTATE_CB_DESTROYING);
466	rtTimerLnxSetState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED);
467
468	while (iCpu-- > 0)
469	if (rtTimerLnxGetState(&pTimer->aSubTimers[iCpu].enmState) != RTTIMERLNXSTATE_STOPPED)
470	{
471	RTSpinlockRelease(pTimer->hSpinlock, &Tmp);
472	return;
473	}
474
475	RTSpinlockRelease(pTimer->hSpinlock, &Tmp);
476	}
477
478	rtTimerLnxDestroyIt(pTimer);
479	}
480
481
482	#ifdef CONFIG_SMP
483	/**
484	* Deal with a sub-timer that has migrated.
485	*
486	* @param pTimer The timer.
487	* @param pSubTimer The sub-timer.
488	*/
489	static void rtTimerLnxCallbackHandleMigration(PRTTIMER pTimer, PRTTIMERLNXSUBTIMER pSubTimer)
490	{
491	RTTIMERLNXSTATE enmState;
492	RTSPINLOCKTMP Tmp = RTSPINLOCKTMP_INITIALIZER;
493	if (pTimer->cCpus > 1)
494	RTSpinlockAcquire(pTimer->hSpinlock, &Tmp);
495
496	do
497	{
498	enmState = rtTimerLnxGetState(&pSubTimer->enmState);
499	switch (enmState)
500	{
501	case RTTIMERLNXSTATE_STOPPING:
502	case RTTIMERLNXSTATE_MP_STOPPING:
503	enmState = RTTIMERLNXSTATE_STOPPED;
504	case RTTIMERLNXSTATE_STOPPED:
505	break;
506
507	default:
508	AssertMsgFailed(("%d\n", enmState));
509	case RTTIMERLNXSTATE_STARTING:
510	case RTTIMERLNXSTATE_MP_STARTING:
511	case RTTIMERLNXSTATE_ACTIVE:
512	case RTTIMERLNXSTATE_CALLBACK:
513	case RTTIMERLNXSTATE_CB_STOPPING:
514	case RTTIMERLNXSTATE_CB_RESTARTING:
515	if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED, enmState))
516	enmState = RTTIMERLNXSTATE_STOPPED;
517	break;
518
519	case RTTIMERLNXSTATE_CB_DESTROYING:
520	{
521	if (pTimer->cCpus > 1)
522	RTSpinlockRelease(pTimer->hSpinlock, &Tmp);
523
524	rtTimerLnxCallbackDestroy(pTimer, pSubTimer);
525	return;
526	}
527	}
528	} while (enmState != RTTIMERLNXSTATE_STOPPED);
529
530	if (pTimer->cCpus > 1)
531	RTSpinlockRelease(pTimer->hSpinlock, &Tmp);
532	}
533	#endif /* CONFIG_SMP */
534
535
536	/**
537	* The slow path of rtTimerLnxChangeToCallbackState.
538	*
539	* @returns true if changed successfully, false if not.
540	* @param pSubTimer The sub-timer.
541	*/
542	static bool rtTimerLnxChangeToCallbackStateSlow(PRTTIMERLNXSUBTIMER pSubTimer)
543	{
544	for (;;)
545	{
546	RTTIMERLNXSTATE enmState = rtTimerLnxGetState(&pSubTimer->enmState);
547	switch (enmState)
548	{
549	case RTTIMERLNXSTATE_ACTIVE:
550	case RTTIMERLNXSTATE_STARTING:
551	case RTTIMERLNXSTATE_MP_STARTING:
552	if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_CALLBACK, enmState))
553	return true;
554	break;
555
556	case RTTIMERLNXSTATE_CALLBACK:
557	case RTTIMERLNXSTATE_CB_STOPPING:
558	case RTTIMERLNXSTATE_CB_RESTARTING:
559	case RTTIMERLNXSTATE_CB_DESTROYING:
560	AssertMsgFailed(("%d\n", enmState));
561	default:
562	return false;
563	}
564	ASMNopPause();
565	}
566	}
567
568
569	/**
570	* Tries to change the sub-timer state to 'callback'.
571	*
572	* @returns true if changed successfully, false if not.
573	* @param pSubTimer The sub-timer.
574	*/
575	DECLINLINE(bool) rtTimerLnxChangeToCallbackState(PRTTIMERLNXSUBTIMER pSubTimer)
576	{
577	if (RT_LIKELY(rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_CALLBACK, RTTIMERLNXSTATE_ACTIVE)))
578	return true;
579	return rtTimerLnxChangeToCallbackStateSlow(pSubTimer);
580	}
581
582
583	#ifdef RTTIMER_LINUX_WITH_HRTIMER
584	/**
585	* Timer callback function for high resolution timers.
586	*
587	* @returns HRTIMER_NORESTART or HRTIMER_RESTART depending on whether it's a
588	* one-shot or interval timer.
589	* @param pHrTimer Pointer to the sub-timer structure.
590	*/
591	static enum hrtimer_restart rtTimerLinuxHrCallback(struct hrtimer *pHrTimer)
592	{
593	PRTTIMERLNXSUBTIMER pSubTimer = RT_FROM_MEMBER(pHrTimer, RTTIMERLNXSUBTIMER, u.Hr.LnxTimer);
594	PRTTIMER pTimer = pSubTimer->pParent;
595
596
597	dprintf(("hrcallback %p\n", pTimer));
598	if (RT_UNLIKELY(!rtTimerLnxChangeToCallbackState(pSubTimer)))
599	return HRTIMER_NORESTART;
600
601	#ifdef CONFIG_SMP
602	/*
603	* Check for unwanted migration.
604	*/
605	if ( pTimer->fAllCpus
606	&& RT_LIKELY((RTCPUID)(pSubTimer - &pTimer->aSubTimers[0]) == RTMpCpuId()))
607	{
608	rtTimerLnxCallbackHandleMigration(pTimer, pSubTimer);
609	return HRTIMER_NORESTART;
610	}
611	#endif
612
613	if (pTimer->u64NanoInterval)
614	{
615	/*
616	* Periodic timer, run it and update the native timer afterwards so
617	* we can handle RTTimerStop and RTTimerChangeInterval from the
618	* callback as well as a racing control thread.
619	*/
620	pTimer->pfnTimer(pTimer, pTimer->pvUser, ++pSubTimer->iTick);
621	hrtimer_add_expires_ns(&pSubTimer->u.Hr.LnxTimer, ASMAtomicReadU64(&pTimer->u64NanoInterval));
622	if (RT_LIKELY(rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_ACTIVE, RTTIMERLNXSTATE_CALLBACK)))
623	return HRTIMER_RESTART;
624	}
625	else
626	{
627	/*
628	* One shot timer (no omni), stop it before dispatching it.
629	* Allow RTTimerStart as well as RTTimerDestroy to be called from
630	* the callback.
631	*/
632	ASMAtomicWriteBool(&pTimer->fSuspended, true);
633	pTimer->pfnTimer(pTimer, pTimer->pvUser, ++pSubTimer->iTick);
634	if (RT_LIKELY(rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED, RTTIMERLNXSTATE_CALLBACK)))
635	return HRTIMER_NORESTART;
636	}
637
638	/*
639	* Some state change occured while we were in the callback routine.
640	*/
641	for (;;)
642	{
643	RTTIMERLNXSTATE enmState = rtTimerLnxGetState(&pSubTimer->enmState);
644	switch (enmState)
645	{
646	case RTTIMERLNXSTATE_CB_DESTROYING:
647	rtTimerLnxCallbackDestroy(pTimer, pSubTimer);
648	return HRTIMER_NORESTART;
649
650	case RTTIMERLNXSTATE_CB_STOPPING:
651	if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED, RTTIMERLNXSTATE_CB_STOPPING))
652	return HRTIMER_NORESTART;
653	break;
654
655	case RTTIMERLNXSTATE_CB_RESTARTING:
656	if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_ACTIVE, RTTIMERLNXSTATE_CB_RESTARTING))
657	{
658	pSubTimer->iTick = 0;
659	hrtimer_set_expires(&pSubTimer->u.Hr.LnxTimer, rtTimerLnxNanoToKt(pSubTimer->uNsRestartAt));
660	return HRTIMER_RESTART;
661	}
662	break;
663
664	default:
665	AssertMsgFailed(("%d\n", enmState));
666	return HRTIMER_NORESTART;
667	}
668	ASMNopPause();
669	}
670	}
671	#endif /* RTTIMER_LINUX_WITH_HRTIMER */
672
673
674	/**
675	* Timer callback function for standard timers.
676	*
677	* @param ulUser Address of the sub-timer structure.
678	*/
679	static void rtTimerLinuxStdCallback(unsigned long ulUser)
680	{
681	PRTTIMERLNXSUBTIMER pSubTimer = (PRTTIMERLNXSUBTIMER)ulUser;
682	PRTTIMER pTimer = pSubTimer->pParent;
683
684	dprintf(("hrcallback %p\n", pTimer));
685	if (RT_UNLIKELY(!rtTimerLnxChangeToCallbackState(pSubTimer)))
686	return;
687
688	#ifdef CONFIG_SMP
689	/*
690	* Check for unwanted migration.
691	*/
692	if ( pTimer->fAllCpus
693	&& RT_LIKELY((RTCPUID)(pSubTimer - &pTimer->aSubTimers[0]) == RTMpCpuId()))
694	{
695	rtTimerLnxCallbackHandleMigration(pTimer, pSubTimer);
696	return;
697	}
698	#endif
699
700	if (pTimer->u64NanoInterval)
701	{
702	/*
703	* Interval timer, calculate the next timeout and re-arm it.
704	*
705	* The first time around, we'll re-adjust the u.Std.u64StartTS to
706	* try prevent some jittering if we were started at a bad time.
707	*/
708	const uint64_t u64NanoInterval = pTimer->u64NanoInterval;
709	const uint64_t iTick = ++pSubTimer->iTick;
710	const uint64_t u64NanoTS = RTTimeNanoTS();
711
712	if (RT_UNLIKELY(iTick == 1))
713	{
714	pSubTimer->u.Std.u64StartTS = u64NanoTS;
715	pSubTimer->u.Std.u64NextTS = u64NanoTS;
716	pSubTimer->u.Std.ulNextJiffies = jiffies;
717	}
718
719	pSubTimer->u.Std.u64NextTS += u64NanoInterval;
720	if (pTimer->cJiffies)
721	{
722	pSubTimer->u.Std.ulNextJiffies += pTimer->cJiffies;
723	/* Prevent overflows when the jiffies counter wraps around.
724	* Special thanks to Ken Preslan for helping debugging! */
725	while (time_before(pSubTimer->u.Std.ulNextJiffies, jiffies))
726	{
727	pSubTimer->u.Std.ulNextJiffies += pTimer->cJiffies;
728	pSubTimer->u.Std.u64NextTS += u64NanoInterval;
729	}
730	}
731	else
732	{
733	while (pSubTimer->u.Std.u64NextTS < u64NanoTS)
734	pSubTimer->u.Std.u64NextTS += u64NanoInterval;
735	pSubTimer->u.Std.ulNextJiffies = jiffies + rtTimerLnxNanoToJiffies(pSubTimer->u.Std.u64NextTS - u64NanoTS);
736	}
737
738	#ifdef CONFIG_SMP
739	if (pTimer->fSpecificCpu \|\| pTimer->fAllCpus)
740	mod_timer_pinned(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
741	else
742	#endif
743	mod_timer(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
744
745	/*
746	* Run the timer.
747	*/
748	pTimer->pfnTimer(pTimer, pTimer->pvUser, iTick);
749	if (RT_LIKELY(rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_ACTIVE, RTTIMERLNXSTATE_CALLBACK)))
750	return;
751	}
752	else
753	{
754	/*
755	* One shot timer, stop it before dispatching it.
756	* Allow RTTimerStart as well as RTTimerDestroy to be called from
757	* the callback.
758	*/
759	ASMAtomicWriteBool(&pTimer->fSuspended, true);
760	pTimer->pfnTimer(pTimer, pTimer->pvUser, ++pSubTimer->iTick);
761	if (RT_LIKELY(rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED, RTTIMERLNXSTATE_CALLBACK)))
762	return;
763	}
764
765	/*
766	* Some state change occured while we were in the callback routine.
767	*/
768	if (pTimer->u64NanoInterval)
769	del_timer_sync(&pSubTimer->u.Std.LnxTimer);
770	for (;;)
771	{
772	RTTIMERLNXSTATE enmState = rtTimerLnxGetState(&pSubTimer->enmState);
773	switch (enmState)
774	{
775	case RTTIMERLNXSTATE_CB_DESTROYING:
776	rtTimerLnxCallbackDestroy(pTimer, pSubTimer);
777	return;
778
779	case RTTIMERLNXSTATE_CB_STOPPING:
780	if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED, RTTIMERLNXSTATE_CB_STOPPING))
781	return;
782	break;
783
784	case RTTIMERLNXSTATE_CB_RESTARTING:
785	if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_ACTIVE, RTTIMERLNXSTATE_CB_RESTARTING))
786	{
787	const uint64_t u64NanoTS = RTTimeNanoTS();
788	const uint64_t u64NextTS = pSubTimer->uNsRestartAt;
789	if (pTimer->fHighRes)
790	{
791	pSubTimer->u.Std.u64StartTS = u64NextTS;
792	pSubTimer->u.Std.u64NextTS = u64NextTS;
793	}
794	pSubTimer->iTick = 0;
795	pSubTimer->u.Std.ulNextJiffies = u64NextTS > u64NanoTS
796	? jiffies + rtTimerLnxNanoToJiffies(u64NextTS - u64NanoTS)
797	: jiffies;
798	#ifdef CONFIG_SMP
799	if (pTimer->fSpecificCpu \|\| pTimer->fAllCpus)
800	mod_timer_pinned(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
801	else
802	#endif
803	mod_timer(&pSubTimer->u.Std.LnxTimer, pSubTimer->u.Std.ulNextJiffies);
804	return;
805	}
806	break;
807
808	default:
809	AssertMsgFailed(("%d\n", enmState));
810	return;
811	}
812	ASMNopPause();
813	}
814	}
815
816
817	#ifdef CONFIG_SMP
818
819	/**
820	* Per-cpu callback function (RTMpOnAll/RTMpOnSpecific).
821	*
822	* @param idCpu The current CPU.
823	* @param pvUser1 Pointer to the timer.
824	* @param pvUser2 Pointer to the argument structure.
825	*/
826	static DECLCALLBACK(void) rtTimerLnxStartAllOnCpu(RTCPUID idCpu, void pvUser1, void pvUser2)
827	{
828	PRTTIMERLINUXSTARTONCPUARGS pArgs = (PRTTIMERLINUXSTARTONCPUARGS)pvUser2;
829	PRTTIMER pTimer = (PRTTIMER)pvUser1;
830	Assert(idCpu < pTimer->cCpus);
831	rtTimerLnxStartSubTimer(&pTimer->aSubTimers[idCpu], pArgs->u64Now, pArgs->u64First, true /fPinned/, pTimer->fHighRes);
832	}
833
834
835	/**
836	* Worker for RTTimerStart() that takes care of the ugly bits.
837	*
838	* @returns RTTimerStart() return value.
839	* @param pTimer The timer.
840	* @param pArgs The argument structure.
841	*/
842	static int rtTimerLnxOmniStart(PRTTIMER pTimer, PRTTIMERLINUXSTARTONCPUARGS pArgs)
843	{
844	RTSPINLOCKTMP Tmp = RTSPINLOCKTMP_INITIALIZER;
845	RTCPUID iCpu;
846	RTCPUSET OnlineSet;
847	RTCPUSET OnlineSet2;
848	int rc2;
849
850	/*
851	* Prepare all the sub-timers for the startup and then flag the timer
852	* as a whole as non-suspended, make sure we get them all before
853	* clearing fSuspended as the MP handler will be waiting on this
854	* should something happen while we're looping.
855	*/
856	RTSpinlockAcquire(pTimer->hSpinlock, &Tmp);
857
858	/* Just make it a omni timer restriction that no stop/start races are allowed. */
859	for (iCpu = 0; iCpu < pTimer->cCpus; iCpu++)
860	if (rtTimerLnxGetState(&pTimer->aSubTimers[iCpu].enmState) != RTTIMERLNXSTATE_STOPPED)
861	{
862	RTSpinlockRelease(pTimer->hSpinlock, &Tmp);
863	return VERR_TIMER_BUSY;
864	}
865
866	do
867	{
868	RTMpGetOnlineSet(&OnlineSet);
869	for (iCpu = 0; iCpu < pTimer->cCpus; iCpu++)
870	{
871	Assert(pTimer->aSubTimers[iCpu].enmState != RTTIMERLNXSTATE_MP_STOPPING);
872	rtTimerLnxSetState(&pTimer->aSubTimers[iCpu].enmState,
873	RTCpuSetIsMember(&OnlineSet, iCpu)
874	? RTTIMERLNXSTATE_STARTING
875	: RTTIMERLNXSTATE_STOPPED);
876	}
877	} while (!RTCpuSetIsEqual(&OnlineSet, RTMpGetOnlineSet(&OnlineSet2)));
878
879	ASMAtomicWriteBool(&pTimer->fSuspended, false);
880
881	RTSpinlockRelease(pTimer->hSpinlock, &Tmp);
882
883	/*
884	* Start them (can't find any exported function that allows me to
885	* do this without the cross calls).
886	*/
887	pArgs->u64Now = RTTimeNanoTS();
888	rc2 = RTMpOnAll(rtTimerLnxStartAllOnCpu, pTimer, pArgs);
889	AssertRC(rc2); /* screw this if it fails. */
890
891	/*
892	* Reset the sub-timers who didn't start up (ALL CPUs case).
893	*/
894	RTSpinlockAcquire(pTimer->hSpinlock, &Tmp);
895
896	for (iCpu = 0; iCpu < pTimer->cCpus; iCpu++)
897	if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[iCpu].enmState, RTTIMERLNXSTATE_STOPPED, RTTIMERLNXSTATE_STARTING))
898	{
899	/** @todo very odd case for a rainy day. Cpus that temporarily went offline while
900	* we were between calls needs to nudged as the MP handler will ignore events for
901	* them because of the STARTING state. This is an extremely unlikely case - not that
902	* that means anything in my experience... ;-) */
903	}
904
905	RTSpinlockRelease(pTimer->hSpinlock, &Tmp);
906
907	return VINF_SUCCESS;
908	}
909
910
911	/**
912	* Worker for RTTimerStop() that takes care of the ugly SMP bits.
913	*
914	* @returns true if there was any active callbacks, false if not.
915	* @param pTimer The timer (valid).
916	* @param fForDestroy Whether this is for RTTimerDestroy or not.
917	*/
918	static bool rtTimerLnxOmniStop(PRTTIMER pTimer, bool fForDestroy)
919	{
920	bool fActiveCallbacks = false;
921	RTSPINLOCKTMP Tmp = RTSPINLOCKTMP_INITIALIZER;
922	RTCPUID iCpu;
923
924
925	/*
926	* Mark the timer as suspended and flag all timers as stopping, except
927	* for those being stopped by an MP event.
928	*/
929	RTSpinlockAcquire(pTimer->hSpinlock, &Tmp);
930
931	ASMAtomicWriteBool(&pTimer->fSuspended, true);
932	for (iCpu = 0; iCpu < pTimer->cCpus; iCpu++)
933	{
934	RTTIMERLNXSTATE enmState;
935	for (;;)
936	{
937	enmState = rtTimerLnxGetState(&pTimer->aSubTimers[iCpu].enmState);
938	if ( enmState == RTTIMERLNXSTATE_STOPPED
939	\|\| enmState == RTTIMERLNXSTATE_MP_STOPPING)
940	break;
941	if ( enmState == RTTIMERLNXSTATE_CALLBACK
942	\|\| enmState == RTTIMERLNXSTATE_CB_STOPPING
943	\|\| enmState == RTTIMERLNXSTATE_CB_RESTARTING)
944	{
945	Assert(enmState != RTTIMERLNXSTATE_CB_STOPPING \|\| fForDestroy);
946	if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[iCpu].enmState,
947	!fForDestroy ? RTTIMERLNXSTATE_CB_STOPPING : RTTIMERLNXSTATE_CB_DESTROYING,
948	enmState))
949	{
950	fActiveCallbacks = true;
951	break;
952	}
953	}
954	else
955	{
956	Assert(enmState == RTTIMERLNXSTATE_ACTIVE);
957	if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[iCpu].enmState, RTTIMERLNXSTATE_STOPPING, enmState))
958	break;
959	}
960	ASMNopPause();
961	}
962	}
963
964	RTSpinlockRelease(pTimer->hSpinlock, &Tmp);
965
966	/*
967	* Do the actual stopping. Fortunately, this doesn't require any IPIs.
968	* Unfortunately it cannot be done synchronously from within the spinlock,
969	* because we might end up in an active waiting for a handler to complete.
970	*/
971	for (iCpu = 0; iCpu < pTimer->cCpus; iCpu++)
972	if (rtTimerLnxGetState(&pTimer->aSubTimers[iCpu].enmState) == RTTIMERLNXSTATE_STOPPING)
973	rtTimerLnxStopSubTimer(&pTimer->aSubTimers[iCpu], pTimer->fHighRes);
974
975	return fActiveCallbacks;
976	}
977
978
979	/**
980	* Per-cpu callback function (RTMpOnSpecific) used by rtTimerLinuxMpEvent()
981	* to start a sub-timer on a cpu that just have come online.
982	*
983	* @param idCpu The current CPU.
984	* @param pvUser1 Pointer to the timer.
985	* @param pvUser2 Pointer to the argument structure.
986	*/
987	static DECLCALLBACK(void) rtTimerLinuxMpStartOnCpu(RTCPUID idCpu, void pvUser1, void pvUser2)
988	{
989	PRTTIMERLINUXSTARTONCPUARGS pArgs = (PRTTIMERLINUXSTARTONCPUARGS)pvUser2;
990	PRTTIMER pTimer = (PRTTIMER)pvUser1;
991	RTSPINLOCK hSpinlock;
992	Assert(idCpu < pTimer->cCpus);
993
994	/*
995	* We have to be kind of careful here as we might be racing RTTimerStop
996	* (and/or RTTimerDestroy, thus the paranoia.
997	*/
998	hSpinlock = pTimer->hSpinlock;
999	if ( hSpinlock != NIL_RTSPINLOCK
1000	&& pTimer->u32Magic == RTTIMER_MAGIC)
1001	{
1002	RTSPINLOCKTMP Tmp = RTSPINLOCKTMP_INITIALIZER;
1003	RTSpinlockAcquire(hSpinlock, &Tmp);
1004
1005	if ( !ASMAtomicUoReadBool(&pTimer->fSuspended)
1006	&& pTimer->u32Magic == RTTIMER_MAGIC)
1007	{
1008	/* We're sane and the timer is not suspended yet. */
1009	PRTTIMERLNXSUBTIMER pSubTimer = &pTimer->aSubTimers[idCpu];
1010	if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_MP_STARTING, RTTIMERLNXSTATE_STOPPED))
1011	rtTimerLnxStartSubTimer(pSubTimer, pArgs->u64Now, pArgs->u64First, true /fPinned/, pTimer->fHighRes);
1012	}
1013
1014	RTSpinlockRelease(hSpinlock, &Tmp);
1015	}
1016	}
1017
1018
1019	/**
1020	* MP event notification callback.
1021	*
1022	* @param enmEvent The event.
1023	* @param idCpu The cpu it applies to.
1024	* @param pvUser The timer.
1025	*/
1026	static DECLCALLBACK(void) rtTimerLinuxMpEvent(RTMPEVENT enmEvent, RTCPUID idCpu, void *pvUser)
1027	{
1028	PRTTIMER pTimer = (PRTTIMER)pvUser;
1029	PRTTIMERLNXSUBTIMER pSubTimer = &pTimer->aSubTimers[idCpu];
1030	RTSPINLOCKTMP Tmp = RTSPINLOCKTMP_INITIALIZER;
1031	RTSPINLOCK hSpinlock;
1032
1033	Assert(idCpu < pTimer->cCpus);
1034
1035	/*
1036	* Some initial paranoia.
1037	*/
1038	if (pTimer->u32Magic != RTTIMER_MAGIC)
1039	return;
1040	hSpinlock = pTimer->hSpinlock;
1041	if (hSpinlock == NIL_RTSPINLOCK)
1042	return;
1043
1044	RTSpinlockAcquire(hSpinlock, &Tmp);
1045
1046	/* Is it active? */
1047	if ( !ASMAtomicUoReadBool(&pTimer->fSuspended)
1048	&& pTimer->u32Magic == RTTIMER_MAGIC)
1049	{
1050	switch (enmEvent)
1051	{
1052	/*
1053	* Try do it without leaving the spin lock, but if we have to, retake it
1054	* when we're on the right cpu.
1055	*/
1056	case RTMPEVENT_ONLINE:
1057	if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_MP_STARTING, RTTIMERLNXSTATE_STOPPED))
1058	{
1059	RTTIMERLINUXSTARTONCPUARGS Args;
1060	Args.u64Now = RTTimeNanoTS();
1061	Args.u64First = 0;
1062
1063	if (RTMpCpuId() == idCpu)
1064	rtTimerLnxStartSubTimer(pSubTimer, Args.u64Now, Args.u64First, true /fPinned/, pTimer->fHighRes);
1065	else
1066	{
1067	rtTimerLnxSetState(&pSubTimer->enmState, RTTIMERLNXSTATE_STOPPED); /* we'll recheck it. */
1068	RTSpinlockRelease(hSpinlock, &Tmp);
1069
1070	RTMpOnSpecific(idCpu, rtTimerLinuxMpStartOnCpu, pTimer, &Args);
1071	return; /* we've left the spinlock */
1072	}
1073	}
1074	break;
1075
1076	/*
1077	* The CPU is (going) offline, make sure the sub-timer is stopped.
1078	*
1079	* Linux will migrate it to a different CPU, but we don't want this. The
1080	* timer function is checking for this.
1081	*/
1082	case RTMPEVENT_OFFLINE:
1083	{
1084	RTTIMERLNXSTATE enmState;
1085	while ( (enmState = rtTimerLnxGetState(&pSubTimer->enmState)) == RTTIMERLNXSTATE_ACTIVE
1086	\|\| enmState == RTTIMERLNXSTATE_CALLBACK
1087	\|\| enmState == RTTIMERLNXSTATE_CB_RESTARTING)
1088	{
1089	if (enmState == RTTIMERLNXSTATE_ACTIVE)
1090	{
1091	if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_MP_STOPPING, RTTIMERLNXSTATE_ACTIVE))
1092	{
1093	RTSpinlockRelease(hSpinlock, &Tmp);
1094
1095	rtTimerLnxStopSubTimer(pSubTimer, pTimer->fHighRes);
1096	return; /* we've left the spinlock */
1097	}
1098	}
1099	else if (rtTimerLnxCmpXchgState(&pSubTimer->enmState, RTTIMERLNXSTATE_CB_STOPPING, enmState))
1100	break;
1101
1102	/* State not stable, try again. */
1103	ASMNopPause();
1104	}
1105	break;
1106	}
1107	}
1108	}
1109
1110	RTSpinlockRelease(hSpinlock, &Tmp);
1111	}
1112
1113	#endif /* CONFIG_SMP */
1114
1115
1116	/**
1117	* Callback function use by RTTimerStart via RTMpOnSpecific to start a timer
1118	* running on a specific CPU.
1119	*
1120	* @param idCpu The current CPU.
1121	* @param pvUser1 Pointer to the timer.
1122	* @param pvUser2 Pointer to the argument structure.
1123	*/
1124	static DECLCALLBACK(void) rtTimerLnxStartOnSpecificCpu(RTCPUID idCpu, void pvUser1, void pvUser2)
1125	{
1126	PRTTIMERLINUXSTARTONCPUARGS pArgs = (PRTTIMERLINUXSTARTONCPUARGS)pvUser2;
1127	PRTTIMER pTimer = (PRTTIMER)pvUser1;
1128	rtTimerLnxStartSubTimer(&pTimer->aSubTimers[0], pArgs->u64Now, pArgs->u64First, true /fPinned/, pTimer->fHighRes);
1129	}
1130
1131
1132	RTDECL(int) RTTimerStart(PRTTIMER pTimer, uint64_t u64First)
1133	{
1134	RTTIMERLINUXSTARTONCPUARGS Args;
1135	int rc2;
1136
1137	/*
1138	* Validate.
1139	*/
1140	AssertPtrReturn(pTimer, VERR_INVALID_HANDLE);
1141	AssertReturn(pTimer->u32Magic == RTTIMER_MAGIC, VERR_INVALID_HANDLE);
1142
1143	if (!ASMAtomicUoReadBool(&pTimer->fSuspended))
1144	return VERR_TIMER_ACTIVE;
1145	dprintf(("start %p\n", pTimer));
1146
1147	Args.u64First = u64First;
1148	#ifdef CONFIG_SMP
1149	/*
1150	* Omni timer?
1151	*/
1152	if (pTimer->fAllCpus)
1153	return rtTimerLnxOmniStart(pTimer, &Args);
1154	#endif
1155
1156	/*
1157	* Simple timer - Pretty straight forward if it wasn't for restarting.
1158	*/
1159	Args.u64Now = RTTimeNanoTS();
1160	ASMAtomicWriteU64(&pTimer->aSubTimers[0].uNsRestartAt, Args.u64Now + u64First);
1161	for (;;)
1162	{
1163	RTTIMERLNXSTATE enmState = rtTimerLnxGetState(&pTimer->aSubTimers[0].enmState);
1164	switch (enmState)
1165	{
1166	case RTTIMERLNXSTATE_STOPPED:
1167	if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[0].enmState, RTTIMERLNXSTATE_STARTING, RTTIMERLNXSTATE_STOPPED))
1168	{
1169	ASMAtomicWriteBool(&pTimer->fSuspended, false);
1170	if (!pTimer->fSpecificCpu)
1171	rtTimerLnxStartSubTimer(&pTimer->aSubTimers[0], Args.u64Now, Args.u64First,
1172	false /fPinned/, pTimer->fHighRes);
1173	else
1174	{
1175	rc2 = RTMpOnSpecific(pTimer->idCpu, rtTimerLnxStartOnSpecificCpu, pTimer, &Args);
1176	if (RT_FAILURE(rc2))
1177	{
1178	/* Suspend it, the cpu id is probably invalid or offline. */
1179	ASMAtomicWriteBool(&pTimer->fSuspended, true);
1180	rtTimerLnxSetState(&pTimer->aSubTimers[0].enmState, RTTIMERLNXSTATE_STOPPED);
1181	return rc2;
1182	}
1183	}
1184	return VINF_SUCCESS;
1185	}
1186	break;
1187
1188	case RTTIMERLNXSTATE_CALLBACK:
1189	case RTTIMERLNXSTATE_CB_STOPPING:
1190	if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[0].enmState, RTTIMERLNXSTATE_CB_RESTARTING, enmState))
1191	{
1192	ASMAtomicWriteBool(&pTimer->fSuspended, false);
1193	return VINF_SUCCESS;
1194	}
1195	break;
1196
1197	default:
1198	AssertMsgFailed(("%d\n", enmState));
1199	return VERR_INTERNAL_ERROR_4;
1200	}
1201	ASMNopPause();
1202	}
1203	}
1204	RT_EXPORT_SYMBOL(RTTimerStart);
1205
1206
1207	/**
1208	* Common worker for RTTimerStop and RTTimerDestroy.
1209	*
1210	* @returns true if there was any active callbacks, false if not.
1211	* @param pTimer The timer to stop.
1212	* @param fForDestroy Whether it's RTTimerDestroy calling or not.
1213	*/
1214	static bool rtTimerLnxStop(PRTTIMER pTimer, bool fForDestroy)
1215	{
1216	dprintf(("lnxstop %p %d\n", pTimer, fForDestroy));
1217	#ifdef CONFIG_SMP
1218	/*
1219	* Omni timer?
1220	*/
1221	if (pTimer->fAllCpus)
1222	return rtTimerLnxOmniStop(pTimer, fForDestroy);
1223	#endif
1224
1225	/*
1226	* Simple timer.
1227	*/
1228	ASMAtomicWriteBool(&pTimer->fSuspended, true);
1229	for (;;)
1230	{
1231	RTTIMERLNXSTATE enmState = rtTimerLnxGetState(&pTimer->aSubTimers[0].enmState);
1232	switch (enmState)
1233	{
1234	case RTTIMERLNXSTATE_ACTIVE:
1235	if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[0].enmState, RTTIMERLNXSTATE_MP_STOPPING, RTTIMERLNXSTATE_ACTIVE))
1236	{
1237	rtTimerLnxStopSubTimer(&pTimer->aSubTimers[0], pTimer->fHighRes);
1238	return false;
1239	}
1240	break;
1241
1242	case RTTIMERLNXSTATE_CALLBACK:
1243	case RTTIMERLNXSTATE_CB_RESTARTING:
1244	case RTTIMERLNXSTATE_CB_STOPPING:
1245	Assert(enmState != RTTIMERLNXSTATE_CB_STOPPING \|\| fForDestroy);
1246	if (rtTimerLnxCmpXchgState(&pTimer->aSubTimers[0].enmState,
1247	!fForDestroy ? RTTIMERLNXSTATE_STOPPED : RTTIMERLNXSTATE_CB_DESTROYING,
1248	enmState))
1249	return true;
1250	break;
1251
1252	case RTTIMERLNXSTATE_STOPPED:
1253	return VINF_SUCCESS;
1254
1255	case RTTIMERLNXSTATE_CB_DESTROYING:
1256	AssertMsgFailed(("enmState=%d pTimer=%p\n", enmState, pTimer));
1257	return true;
1258
1259	default:
1260	case RTTIMERLNXSTATE_STARTING:
1261	case RTTIMERLNXSTATE_MP_STARTING:
1262	case RTTIMERLNXSTATE_STOPPING:
1263	case RTTIMERLNXSTATE_MP_STOPPING:
1264	AssertMsgFailed(("enmState=%d pTimer=%p\n", enmState, pTimer));
1265	return false;
1266	}
1267
1268	/* State not stable, try again. */
1269	ASMNopPause();
1270	}
1271	}
1272
1273
1274	RTDECL(int) RTTimerStop(PRTTIMER pTimer)
1275	{
1276	/*
1277	* Validate.
1278	*/
1279	AssertPtrReturn(pTimer, VERR_INVALID_HANDLE);
1280	AssertReturn(pTimer->u32Magic == RTTIMER_MAGIC, VERR_INVALID_HANDLE);
1281	dprintf(("stop %p\n", pTimer));
1282
1283	if (ASMAtomicUoReadBool(&pTimer->fSuspended))
1284	return VERR_TIMER_SUSPENDED;
1285
1286	rtTimerLnxStop(pTimer, false /fForDestroy/);
1287	return VINF_SUCCESS;
1288	}
1289	RT_EXPORT_SYMBOL(RTTimerStop);
1290
1291
1292	RTDECL(int) RTTimerChangeInterval(PRTTIMER pTimer, uint64_t u64NanoInterval)
1293	{
1294	/*
1295	* Validate.
1296	*/
1297	AssertPtrReturn(pTimer, VERR_INVALID_HANDLE);
1298	AssertReturn(pTimer->u32Magic == RTTIMER_MAGIC, VERR_INVALID_HANDLE);
1299	AssertReturn(u64NanoInterval, VERR_INVALID_PARAMETER);
1300	dprintf(("change %p %llu\n", pTimer, u64NanoInterval));
1301
1302	#ifdef RTTIMER_LINUX_WITH_HRTIMER
1303	/*
1304	* For the high resolution timers it is easy since we don't care so much
1305	* about when it is applied to the sub-timers.
1306	*/
1307	if (pTimer->fHighRes)
1308	{
1309	ASMAtomicWriteU64(&pTimer->u64NanoInterval, u64NanoInterval);
1310	return VINF_SUCCESS;
1311	}
1312	#endif
1313
1314	/*
1315	* Standard timers have a bit more complicated way of calculating
1316	* their interval and such. So, forget omni timers for now.
1317	*/
1318	if (pTimer->cCpus > 1)
1319	return VERR_NOT_SUPPORTED;
1320	RTTimerStop(pTimer);
1321	return RTTimerStart(pTimer, u64NanoInterval);
1322	}
1323	RT_EXPORT_SYMBOL(RTTimerChangeInterval);
1324
1325
1326	RTDECL(int) RTTimerDestroy(PRTTIMER pTimer)
1327	{
1328	bool fCanDestroy;
1329
1330	/*
1331	* Validate. It's ok to pass NULL pointer.
1332	*/
1333	if (pTimer == /NIL_RTTIMER/ NULL)
1334	return VINF_SUCCESS;
1335	AssertPtrReturn(pTimer, VERR_INVALID_HANDLE);
1336	AssertReturn(pTimer->u32Magic == RTTIMER_MAGIC, VERR_INVALID_HANDLE);
1337	dprintf(("destroy %p\n", pTimer));
1338
1339	/*
1340	* Stop the timer if it's still active, then destroy it if we can.
1341	*/
1342	if (!ASMAtomicUoReadBool(&pTimer->fSuspended))
1343	fCanDestroy = rtTimerLnxStop(pTimer, true /fForDestroy/);
1344	else
1345	{
1346	uint32_t iCpu = pTimer->cCpus;
1347	RTSPINLOCKTMP Tmp = RTSPINLOCKTMP_INITIALIZER;
1348	if (pTimer->cCpus > 1)
1349	RTSpinlockAcquireNoInts(pTimer->hSpinlock, &Tmp);
1350
1351	fCanDestroy = true;
1352	while (iCpu-- > 0)
1353	{
1354	for (;;)
1355	{
1356	RTTIMERLNXSTATE enmState = rtTimerLnxGetState(&pTimer->aSubTimers[iCpu].enmState);
1357	switch (enmState)
1358	{
1359	case RTTIMERLNXSTATE_CALLBACK:
1360	case RTTIMERLNXSTATE_CB_RESTARTING:
1361	case RTTIMERLNXSTATE_CB_STOPPING:
1362	if (!rtTimerLnxCmpXchgState(&pTimer->aSubTimers[iCpu].enmState, RTTIMERLNXSTATE_CB_DESTROYING, enmState))
1363	continue;
1364	fCanDestroy = false;
1365	break;
1366
1367	case RTTIMERLNXSTATE_CB_DESTROYING:
1368	AssertMsgFailed(("%d\n", enmState));
1369	fCanDestroy = false;
1370	break;
1371	default:
1372	break;
1373	}
1374	break;
1375	}
1376	}
1377
1378	if (pTimer->cCpus > 1)
1379	RTSpinlockReleaseNoInts(pTimer->hSpinlock, &Tmp);
1380	}
1381
1382	if (fCanDestroy)
1383	rtTimerLnxDestroyIt(pTimer);
1384
1385	return VINF_SUCCESS;
1386	}
1387	RT_EXPORT_SYMBOL(RTTimerDestroy);
1388
1389
1390	RTDECL(int) RTTimerCreateEx(PRTTIMER ppTimer, uint64_t u64NanoInterval, uint32_t fFlags, PFNRTTIMER pfnTimer, void pvUser)
1391	{
1392	PRTTIMER pTimer;
1393	RTCPUID iCpu;
1394	unsigned cCpus;
1395
1396	*ppTimer = NULL;
1397
1398	/*
1399	* Validate flags.
1400	*/
1401	if (!RTTIMER_FLAGS_ARE_VALID(fFlags))
1402	return VERR_INVALID_PARAMETER;
1403	if ( (fFlags & RTTIMER_FLAGS_CPU_SPECIFIC)
1404	&& (fFlags & RTTIMER_FLAGS_CPU_ALL) != RTTIMER_FLAGS_CPU_ALL
1405	&& !RTMpIsCpuPossible(RTMpCpuIdFromSetIndex(fFlags & RTTIMER_FLAGS_CPU_MASK)))
1406	return VERR_CPU_NOT_FOUND;
1407
1408	/*
1409	* Allocate the timer handler.
1410	*/
1411	cCpus = 1;
1412	#ifdef CONFIG_SMP
1413	if ((fFlags & RTTIMER_FLAGS_CPU_ALL) == RTTIMER_FLAGS_CPU_ALL)
1414	{
1415	cCpus = RTMpGetMaxCpuId() + 1;
1416	Assert(cCpus <= RTCPUSET_MAX_CPUS); /* On linux we have a 1:1 relationship between cpuid and set index. */
1417	AssertReturn(u64NanoInterval, VERR_NOT_IMPLEMENTED); /* We don't implement single shot on all cpus, sorry. */
1418	}
1419	#endif
1420
1421	pTimer = (PRTTIMER)RTMemAllocZ(RT_OFFSETOF(RTTIMER, aSubTimers[cCpus]));
1422	if (!pTimer)
1423	return VERR_NO_MEMORY;
1424
1425	/*
1426	* Initialize it.
1427	*/
1428	pTimer->u32Magic = RTTIMER_MAGIC;
1429	pTimer->hSpinlock = NIL_RTSPINLOCK;
1430	pTimer->fSuspended = true;
1431	pTimer->fHighRes = !!(fFlags & RTTIMER_FLAGS_HIGH_RES);
1432	#ifdef CONFIG_SMP
1433	pTimer->fSpecificCpu = (fFlags & RTTIMER_FLAGS_CPU_SPECIFIC) && (fFlags & RTTIMER_FLAGS_CPU_ALL) != RTTIMER_FLAGS_CPU_ALL;
1434	pTimer->fAllCpus = (fFlags & RTTIMER_FLAGS_CPU_ALL) == RTTIMER_FLAGS_CPU_ALL;
1435	pTimer->idCpu = pTimer->fSpecificCpu
1436	? RTMpCpuIdFromSetIndex(fFlags & RTTIMER_FLAGS_CPU_MASK)
1437	: NIL_RTCPUID;
1438	#else
1439	pTimer->fSpecificCpu = !!(fFlags & RTTIMER_FLAGS_CPU_SPECIFIC);
1440	pTimer->idCpu = RTMpCpuId();
1441	#endif
1442	pTimer->cCpus = cCpus;
1443	pTimer->pfnTimer = pfnTimer;
1444	pTimer->pvUser = pvUser;
1445	pTimer->u64NanoInterval = u64NanoInterval;
1446	pTimer->cJiffies = u64NanoInterval / RTTimerGetSystemGranularity();
1447	if (pTimer->cJiffies * RTTimerGetSystemGranularity() != u64NanoInterval)
1448	pTimer->cJiffies = 0;
1449
1450	for (iCpu = 0; iCpu < cCpus; iCpu++)
1451	{
1452	#ifdef RTTIMER_LINUX_WITH_HRTIMER
1453	if (pTimer->fHighRes)
1454	{
1455	hrtimer_init(&pTimer->aSubTimers[iCpu].u.Hr.LnxTimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
1456	pTimer->aSubTimers[iCpu].u.Hr.LnxTimer.function = rtTimerLinuxHrCallback;
1457	}
1458	else
1459	#endif
1460	{
1461	init_timer(&pTimer->aSubTimers[iCpu].u.Std.LnxTimer);
1462	pTimer->aSubTimers[iCpu].u.Std.LnxTimer.data = (unsigned long)&pTimer->aSubTimers[iCpu];
1463	pTimer->aSubTimers[iCpu].u.Std.LnxTimer.function = rtTimerLinuxStdCallback;
1464	pTimer->aSubTimers[iCpu].u.Std.LnxTimer.expires = jiffies;
1465	pTimer->aSubTimers[iCpu].u.Std.u64StartTS = 0;
1466	pTimer->aSubTimers[iCpu].u.Std.u64NextTS = 0;
1467	}
1468	pTimer->aSubTimers[iCpu].iTick = 0;
1469	pTimer->aSubTimers[iCpu].pParent = pTimer;
1470	pTimer->aSubTimers[iCpu].enmState = RTTIMERLNXSTATE_STOPPED;
1471	}
1472
1473	#ifdef CONFIG_SMP
1474	/*
1475	* If this is running on ALL cpus, we'll have to register a callback
1476	* for MP events (so timers can be started/stopped on cpus going
1477	* online/offline). We also create the spinlock for syncrhonizing
1478	* stop/start/mp-event.
1479	*/
1480	if (cCpus > 1)
1481	{
1482	int rc = RTSpinlockCreate(&pTimer->hSpinlock);
1483	if (RT_SUCCESS(rc))
1484	rc = RTMpNotificationRegister(rtTimerLinuxMpEvent, pTimer);
1485	else
1486	pTimer->hSpinlock = NIL_RTSPINLOCK;
1487	if (RT_FAILURE(rc))
1488	{
1489	RTTimerDestroy(pTimer);
1490	return rc;
1491	}
1492	}
1493	#endif /* CONFIG_SMP */
1494
1495	dprintf(("create %p\n", pTimer));
1496	*ppTimer = pTimer;
1497	return VINF_SUCCESS;
1498	}
1499	RT_EXPORT_SYMBOL(RTTimerCreateEx);
1500
1501
1502	RTDECL(uint32_t) RTTimerGetSystemGranularity(void)
1503	{
1504	#if 0 /** @todo Not sure if this is what we want or not... Add new API for
1505	* querying the resolution of the high res timers? */
1506	struct timespec Ts;
1507	int rc = hrtimer_get_res(CLOCK_MONOTONIC, &Ts);
1508	if (!rc)
1509	{
1510	Assert(!Ts.tv_sec);
1511	return Ts.tv_nsec;
1512	}
1513	#endif
1514	return 1000000000 / HZ; /* ns */
1515	}
1516	RT_EXPORT_SYMBOL(RTTimerGetSystemGranularity);
1517
1518
1519	RTDECL(int) RTTimerRequestSystemGranularity(uint32_t u32Request, uint32_t *pu32Granted)
1520	{
1521	return VERR_NOT_SUPPORTED;
1522	}
1523	RT_EXPORT_SYMBOL(RTTimerRequestSystemGranularity);
1524
1525
1526	RTDECL(int) RTTimerReleaseSystemGranularity(uint32_t u32Granted)
1527	{
1528	return VERR_NOT_SUPPORTED;
1529	}
1530	RT_EXPORT_SYMBOL(RTTimerReleaseSystemGranularity);
1531
1532
1533	RTDECL(bool) RTTimerCanDoHighResolution(void)
1534	{
1535	#ifdef RTTIMER_LINUX_WITH_HRTIMER
1536	return true;
1537	#else
1538	return false;
1539	#endif
1540	}
1541	RT_EXPORT_SYMBOL(RTTimerCanDoHighResolution);
1542

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source: vbox/trunk/src/VBox/Runtime/r0drv/linux/timer-r0drv-linux.c@ 32670

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