aboutsummaryrefslogtreecommitdiff
path: root/drivers/staging/epl/TimerHighReskX86.c
blob: 82eee4702aa67b7a80e412aada765cae2ddc2fb1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
/****************************************************************************

  (c) SYSTEC electronic GmbH, D-07973 Greiz, August-Bebel-Str. 29
      www.systec-electronic.com

  Project:      openPOWERLINK

  Description:  target specific implementation of
                high resolution timer module for X86 under Linux
                The Linux kernel has to be compiled with high resolution
                timers enabled. This is done by configuring the kernel
                with CONFIG_HIGH_RES_TIMERS enabled.

  License:

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.

    3. Neither the name of SYSTEC electronic GmbH nor the names of its
       contributors may be used to endorse or promote products derived
       from this software without prior written permission. For written
       permission, please contact info@systec-electronic.com.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
    COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.

    Severability Clause:

        If a provision of this License is or becomes illegal, invalid or
        unenforceable in any jurisdiction, that shall not affect:
        1. the validity or enforceability in that jurisdiction of any other
           provision of this License; or
        2. the validity or enforceability in other jurisdictions of that or
           any other provision of this License.

  -------------------------------------------------------------------------

                $RCSfile: TimerHighReskX86.c,v $

                $Author: D.Krueger $

                $Revision: 1.4 $  $Date: 2008/04/17 21:38:01 $

                $State: Exp $

                Build Environment:
                    GNU

  -------------------------------------------------------------------------

  Revision History:

****************************************************************************/

#include "EplInc.h"
#include "kernel/EplTimerHighResk.h"
#include "Benchmark.h"

//#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/hrtimer.h>

/***************************************************************************/
/*                                                                         */
/*                                                                         */
/*          G L O B A L   D E F I N I T I O N S                            */
/*                                                                         */
/*                                                                         */
/***************************************************************************/

//---------------------------------------------------------------------------
// const defines
//---------------------------------------------------------------------------

#define TIMER_COUNT           2	/* max 15 timers selectable */
#define TIMER_MIN_VAL_SINGLE  5000	/* min 5us */
#define TIMER_MIN_VAL_CYCLE   100000	/* min 100us */

#define PROVE_OVERRUN

#ifndef CONFIG_HIGH_RES_TIMERS
#error "Kernel symbol CONFIG_HIGH_RES_TIMERS is required."
#endif

// TracePoint support for realtime-debugging
#ifdef _DBG_TRACE_POINTS_
void PUBLIC TgtDbgSignalTracePoint(BYTE bTracePointNumber_p);
void PUBLIC TgtDbgPostTraceValue(DWORD dwTraceValue_p);
#define TGT_DBG_SIGNAL_TRACE_POINT(p)   TgtDbgSignalTracePoint(p)
#define TGT_DBG_POST_TRACE_VALUE(v)     TgtDbgPostTraceValue(v)
#else
#define TGT_DBG_SIGNAL_TRACE_POINT(p)
#define TGT_DBG_POST_TRACE_VALUE(v)
#endif
#define HRT_DBG_POST_TRACE_VALUE(Event_p, uiNodeId_p, wErrorCode_p) \
    TGT_DBG_POST_TRACE_VALUE((0xE << 28) | (Event_p << 24) \
                             | (uiNodeId_p << 16) | wErrorCode_p)

#define TIMERHDL_MASK         0x0FFFFFFF
#define TIMERHDL_SHIFT        28
#define HDL_TO_IDX(Hdl)       ((Hdl >> TIMERHDL_SHIFT) - 1)
#define HDL_INIT(Idx)         ((Idx + 1) << TIMERHDL_SHIFT)
#define HDL_INC(Hdl)          (((Hdl + 1) & TIMERHDL_MASK) \
                               | (Hdl & ~TIMERHDL_MASK))

//---------------------------------------------------------------------------
// modul global types
//---------------------------------------------------------------------------

typedef struct {
	tEplTimerEventArg m_EventArg;
	tEplTimerkCallback m_pfnCallback;
	struct hrtimer m_Timer;
	BOOL m_fContinuously;
	unsigned long long m_ullPeriod;

} tEplTimerHighReskTimerInfo;

typedef struct {
	tEplTimerHighReskTimerInfo m_aTimerInfo[TIMER_COUNT];

} tEplTimerHighReskInstance;

//---------------------------------------------------------------------------
// local vars
//---------------------------------------------------------------------------

static tEplTimerHighReskInstance EplTimerHighReskInstance_l;

//---------------------------------------------------------------------------
// local function prototypes
//---------------------------------------------------------------------------

enum hrtimer_restart EplTimerHighReskCallback(struct hrtimer *pTimer_p);

//=========================================================================//
//                                                                         //
//          P U B L I C   F U N C T I O N S                                //
//                                                                         //
//=========================================================================//

//---------------------------------------------------------------------------
//
// Function:    EplTimerHighReskInit()
//
// Description: initializes the high resolution timer module.
//
// Parameters:  void
//
// Return:      tEplKernel      = error code
//
// State:       not tested
//
//---------------------------------------------------------------------------

tEplKernel PUBLIC EplTimerHighReskInit(void)
{
	tEplKernel Ret;

	Ret = EplTimerHighReskAddInstance();

	return Ret;

}

//---------------------------------------------------------------------------
//
// Function:    EplTimerHighReskAddInstance()
//
// Description: initializes the high resolution timer module.
//
// Parameters:  void
//
// Return:      tEplKernel      = error code
//
// State:       not tested
//
//---------------------------------------------------------------------------

tEplKernel PUBLIC EplTimerHighReskAddInstance(void)
{
	tEplKernel Ret;
	unsigned int uiIndex;

	Ret = kEplSuccessful;

	EPL_MEMSET(&EplTimerHighReskInstance_l, 0,
		   sizeof(EplTimerHighReskInstance_l));

#ifndef CONFIG_HIGH_RES_TIMERS
	printk
	    ("EplTimerHighResk: Kernel symbol CONFIG_HIGH_RES_TIMERS is required.\n");
	Ret = kEplNoResource;
	return Ret;
#endif

	/*
	 * Initialize hrtimer structures for all usable timers.
	 */
	for (uiIndex = 0; uiIndex < TIMER_COUNT; uiIndex++) {
		tEplTimerHighReskTimerInfo *pTimerInfo;
		struct hrtimer *pTimer;

		pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[uiIndex];
		pTimer = &pTimerInfo->m_Timer;
		hrtimer_init(pTimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);

		pTimer->function = EplTimerHighReskCallback;
	}

	return Ret;
}

//---------------------------------------------------------------------------
//
// Function:    EplTimerHighReskDelInstance()
//
// Description: shuts down the high resolution timer module.
//
// Parameters:  void
//
// Return:      tEplKernel      = error code
//
// State:       not tested
//
//---------------------------------------------------------------------------

tEplKernel PUBLIC EplTimerHighReskDelInstance(void)
{
	tEplTimerHighReskTimerInfo *pTimerInfo;
	tEplKernel Ret;
	unsigned int uiIndex;

	Ret = kEplSuccessful;

	for (uiIndex = 0; uiIndex < TIMER_COUNT; uiIndex++) {
		pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[0];
		pTimerInfo->m_pfnCallback = NULL;
		pTimerInfo->m_EventArg.m_TimerHdl = 0;
		/*
		 * In this case we can not just try to cancel the timer.
		 * We actually have to wait until its callback function
		 * has returned.
		 */
		hrtimer_cancel(&pTimerInfo->m_Timer);
	}

	return Ret;

}

//---------------------------------------------------------------------------
//
// Function:    EplTimerHighReskModifyTimerNs()
//
// Description: modifies the timeout of the timer with the specified handle.
//              If the handle the pointer points to is zero, the timer must
//              be created first.
//              If it is not possible to stop the old timer,
//              this function always assures that the old timer does not
//              trigger the callback function with the same handle as the new
//              timer. That means the callback function must check the passed
//              handle with the one returned by this function. If these are
//              unequal, the call can be discarded.
//
// Parameters:  pTimerHdl_p     = pointer to timer handle
//              ullTimeNs_p     = relative timeout in [ns]
//              pfnCallback_p   = callback function, which is called mutual
//                                exclusive with the Edrv callback functions
//                                (Rx and Tx).
//              ulArgument_p    = user-specific argument
//              fContinuously_p = if TRUE, callback function will be called
//                                continuously;
//                                otherwise, it is a oneshot timer.
//
// Return:      tEplKernel      = error code
//
// State:       not tested
//
//---------------------------------------------------------------------------

tEplKernel PUBLIC EplTimerHighReskModifyTimerNs(tEplTimerHdl * pTimerHdl_p,
						unsigned long long ullTimeNs_p,
						tEplTimerkCallback
						pfnCallback_p,
						unsigned long ulArgument_p,
						BOOL fContinuously_p)
{
	tEplKernel Ret;
	unsigned int uiIndex;
	tEplTimerHighReskTimerInfo *pTimerInfo;
	ktime_t RelTime;

	Ret = kEplSuccessful;

	// check pointer to handle
	if (pTimerHdl_p == NULL) {
		Ret = kEplTimerInvalidHandle;
		goto Exit;
	}

	if (*pTimerHdl_p == 0) {	// no timer created yet

		// search free timer info structure
		pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[0];
		for (uiIndex = 0; uiIndex < TIMER_COUNT;
		     uiIndex++, pTimerInfo++) {
			if (pTimerInfo->m_EventArg.m_TimerHdl == 0) {	// free structure found
				break;
			}
		}
		if (uiIndex >= TIMER_COUNT) {	// no free structure found
			Ret = kEplTimerNoTimerCreated;
			goto Exit;
		}

		pTimerInfo->m_EventArg.m_TimerHdl = HDL_INIT(uiIndex);
	} else {
		uiIndex = HDL_TO_IDX(*pTimerHdl_p);
		if (uiIndex >= TIMER_COUNT) {	// invalid handle
			Ret = kEplTimerInvalidHandle;
			goto Exit;
		}

		pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[uiIndex];
	}

	/*
	 * increment timer handle
	 * (if timer expires right after this statement, the user
	 * would detect an unknown timer handle and discard it)
	 */
	pTimerInfo->m_EventArg.m_TimerHdl =
	    HDL_INC(pTimerInfo->m_EventArg.m_TimerHdl);
	*pTimerHdl_p = pTimerInfo->m_EventArg.m_TimerHdl;

	// reject too small time values
	if ((fContinuously_p && (ullTimeNs_p < TIMER_MIN_VAL_CYCLE))
	    || (!fContinuously_p && (ullTimeNs_p < TIMER_MIN_VAL_SINGLE))) {
		Ret = kEplTimerNoTimerCreated;
		goto Exit;
	}

	pTimerInfo->m_EventArg.m_ulArg = ulArgument_p;
	pTimerInfo->m_pfnCallback = pfnCallback_p;
	pTimerInfo->m_fContinuously = fContinuously_p;
	pTimerInfo->m_ullPeriod = ullTimeNs_p;

	/*
	 * HRTIMER_MODE_REL does not influence general handling of this timer.
	 * It only sets relative mode for this start operation.
	 * -> Expire time is calculated by: Now + RelTime
	 * hrtimer_start also skips pending timer events.
	 * The state HRTIMER_STATE_CALLBACK is ignored.
	 * We have to cope with that in our callback function.
	 */
	RelTime = ktime_add_ns(ktime_set(0, 0), ullTimeNs_p);
	hrtimer_start(&pTimerInfo->m_Timer, RelTime, HRTIMER_MODE_REL);

      Exit:
	return Ret;

}

//---------------------------------------------------------------------------
//
// Function:    EplTimerHighReskDeleteTimer()
//
// Description: deletes the timer with the specified handle. Afterward the
//              handle is set to zero.
//
// Parameters:  pTimerHdl_p     = pointer to timer handle
//
// Return:      tEplKernel      = error code
//
// State:       not tested
//
//---------------------------------------------------------------------------

tEplKernel PUBLIC EplTimerHighReskDeleteTimer(tEplTimerHdl * pTimerHdl_p)
{
	tEplKernel Ret = kEplSuccessful;
	unsigned int uiIndex;
	tEplTimerHighReskTimerInfo *pTimerInfo;

	// check pointer to handle
	if (pTimerHdl_p == NULL) {
		Ret = kEplTimerInvalidHandle;
		goto Exit;
	}

	if (*pTimerHdl_p == 0) {	// no timer created yet
		goto Exit;
	} else {
		uiIndex = HDL_TO_IDX(*pTimerHdl_p);
		if (uiIndex >= TIMER_COUNT) {	// invalid handle
			Ret = kEplTimerInvalidHandle;
			goto Exit;
		}
		pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[uiIndex];
		if (pTimerInfo->m_EventArg.m_TimerHdl != *pTimerHdl_p) {	// invalid handle
			goto Exit;
		}
	}

	*pTimerHdl_p = 0;
	pTimerInfo->m_EventArg.m_TimerHdl = 0;
	pTimerInfo->m_pfnCallback = NULL;

	/*
	 * Three return cases of hrtimer_try_to_cancel have to be tracked:
	 *  1 - timer has been removed
	 *  0 - timer was not active
	 *      We need not do anything. hrtimer timers just consist of
	 *      a hrtimer struct, which we might enqueue in the hrtimers
	 *      event list by calling hrtimer_start().
	 *      If a timer is not enqueued, it is not present in hrtimers.
	 * -1 - callback function is running
	 *      In this case we have to ensure that the timer is not
	 *      continuously restarted. This has been done by clearing
	 *      its handle.
	 */
	hrtimer_try_to_cancel(&pTimerInfo->m_Timer);

      Exit:
	return Ret;

}

//---------------------------------------------------------------------------
//
// Function:    EplTimerHighReskCallback()
//
// Description: Callback function commonly used for all timers.
//
// Parameters:  pTimer_p = pointer to hrtimer
//
// Return:
//
// State:       not tested
//
//---------------------------------------------------------------------------

enum hrtimer_restart EplTimerHighReskCallback(struct hrtimer *pTimer_p)
{
	unsigned int uiIndex;
	tEplTimerHighReskTimerInfo *pTimerInfo;
	tEplTimerHdl OrgTimerHdl;
	enum hrtimer_restart Ret;

	BENCHMARK_MOD_24_SET(4);

	Ret = HRTIMER_NORESTART;
	pTimerInfo =
	    container_of(pTimer_p, tEplTimerHighReskTimerInfo, m_Timer);
	uiIndex = HDL_TO_IDX(pTimerInfo->m_EventArg.m_TimerHdl);
	if (uiIndex >= TIMER_COUNT) {	// invalid handle
		goto Exit;
	}

	/*
	 * We store the timer handle before calling the callback function
	 * as the timer can be modified inside it.
	 */
	OrgTimerHdl = pTimerInfo->m_EventArg.m_TimerHdl;

	if (pTimerInfo->m_pfnCallback != NULL) {
		pTimerInfo->m_pfnCallback(&pTimerInfo->m_EventArg);
	}

	if (pTimerInfo->m_fContinuously) {
		ktime_t Interval;
#ifdef PROVE_OVERRUN
		ktime_t Now;
		unsigned long Overruns;
#endif

		if (OrgTimerHdl != pTimerInfo->m_EventArg.m_TimerHdl) {
			/* modified timer has already been restarted */
			goto Exit;
		}
#ifdef PROVE_OVERRUN
		Now = ktime_get();
		Interval =
		    ktime_add_ns(ktime_set(0, 0), pTimerInfo->m_ullPeriod);
		Overruns = hrtimer_forward(pTimer_p, Now, Interval);
		if (Overruns > 1) {
			printk
			    ("EplTimerHighResk: Continuous timer (handle 0x%lX) had to skip %lu interval(s)!\n",
			     pTimerInfo->m_EventArg.m_TimerHdl, Overruns - 1);
		}
#else
		pTimer_p->expires = ktime_add_ns(pTimer_p->expires,
						 pTimerInfo->m_ullPeriod);
#endif

		Ret = HRTIMER_RESTART;
	}

      Exit:
	BENCHMARK_MOD_24_RESET(4);
	return Ret;
}