git.oblomov.eu Git - linux-2.6/blob - drivers/staging/epl/TimerHighReskX86.c

   1 /****************************************************************************
   2
   3   (c) SYSTEC electronic GmbH, D-07973 Greiz, August-Bebel-Str. 29
   4       www.systec-electronic.com
   5
   6   Project:      openPOWERLINK
   7
   8   Description:  target specific implementation of
   9                 high resolution timer module for X86 under Linux
  10                 The Linux kernel has to be compiled with high resolution
  11                 timers enabled. This is done by configuring the kernel
  12                 with CONFIG_HIGH_RES_TIMERS enabled.
  13
  14   License:
  15
  16     Redistribution and use in source and binary forms, with or without
  17     modification, are permitted provided that the following conditions
  18     are met:
  19
  20     1. Redistributions of source code must retain the above copyright
  21        notice, this list of conditions and the following disclaimer.
  22
  23     2. Redistributions in binary form must reproduce the above copyright
  24        notice, this list of conditions and the following disclaimer in the
  25        documentation and/or other materials provided with the distribution.
  26
  27     3. Neither the name of SYSTEC electronic GmbH nor the names of its
  28        contributors may be used to endorse or promote products derived
  29        from this software without prior written permission. For written
  30        permission, please contact info@systec-electronic.com.
  31
  32     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  35     FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  36     COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  37     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  38     BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  39     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  40     CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  41     LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  42     ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  43     POSSIBILITY OF SUCH DAMAGE.
  44
  45     Severability Clause:
  46
  47         If a provision of this License is or becomes illegal, invalid or
  48         unenforceable in any jurisdiction, that shall not affect:
  49         1. the validity or enforceability in that jurisdiction of any other
  50            provision of this License; or
  51         2. the validity or enforceability in other jurisdictions of that or
  52            any other provision of this License.
  53
  54   -------------------------------------------------------------------------
  55
  56                 $RCSfile: TimerHighReskX86.c,v $
  57
  58                 $Author: D.Krueger $
  59
  60                 $Revision: 1.4 $  $Date: 2008/04/17 21:38:01 $
  61
  62                 $State: Exp $
  63
  64                 Build Environment:
  65                     GNU
  66
  67   -------------------------------------------------------------------------
  68
  69   Revision History:
  70
  71 ****************************************************************************/
  72
  73 #include "EplInc.h"
  74 #include "kernel/EplTimerHighResk.h"
  75 #include "Benchmark.h"
  76
  77 //#include <linux/config.h>
  78 #include <linux/module.h>
  79 #include <linux/kernel.h>
  80 #include <linux/hrtimer.h>
  81
  82 /***************************************************************************/
  83 /*                                                                         */
  84 /*                                                                         */
  85 /*          G L O B A L   D E F I N I T I O N S                            */
  86 /*                                                                         */
  87 /*                                                                         */
  88 /***************************************************************************/
  89
  90 //---------------------------------------------------------------------------
  91 // const defines
  92 //---------------------------------------------------------------------------
  93
  94 #define TIMER_COUNT           2 /* max 15 timers selectable */
  95 #define TIMER_MIN_VAL_SINGLE  5000      /* min 5us */
  96 #define TIMER_MIN_VAL_CYCLE   100000    /* min 100us */
  97
  98 #define PROVE_OVERRUN
  99
 100 // TracePoint support for realtime-debugging
 101 #ifdef _DBG_TRACE_POINTS_
 102 void TgtDbgSignalTracePoint(u8 bTracePointNumber_p);
 103 void TgtDbgPostTraceValue(u32 dwTraceValue_p);
 104 #define TGT_DBG_SIGNAL_TRACE_POINT(p)   TgtDbgSignalTracePoint(p)
 105 #define TGT_DBG_POST_TRACE_VALUE(v)     TgtDbgPostTraceValue(v)
 106 #else
 107 #define TGT_DBG_SIGNAL_TRACE_POINT(p)
 108 #define TGT_DBG_POST_TRACE_VALUE(v)
 109 #endif
 110 #define HRT_DBG_POST_TRACE_VALUE(Event_p, uiNodeId_p, wErrorCode_p) \
 111     TGT_DBG_POST_TRACE_VALUE((0xE << 28) | (Event_p << 24) \
 112                              | (uiNodeId_p << 16) | wErrorCode_p)
 113
 114 #define TIMERHDL_MASK         0x0FFFFFFF
 115 #define TIMERHDL_SHIFT        28
 116 #define HDL_TO_IDX(Hdl)       ((Hdl >> TIMERHDL_SHIFT) - 1)
 117 #define HDL_INIT(Idx)         ((Idx + 1) << TIMERHDL_SHIFT)
 118 #define HDL_INC(Hdl)          (((Hdl + 1) & TIMERHDL_MASK) \
 119                                | (Hdl & ~TIMERHDL_MASK))
 120
 121 //---------------------------------------------------------------------------
 122 // modul global types
 123 //---------------------------------------------------------------------------
 124
 125 typedef struct {
 126         tEplTimerEventArg m_EventArg;
 127         tEplTimerkCallback m_pfnCallback;
 128         struct hrtimer m_Timer;
 129         BOOL m_fContinuously;
 130         unsigned long long m_ullPeriod;
 131
 132 } tEplTimerHighReskTimerInfo;
 133
 134 typedef struct {
 135         tEplTimerHighReskTimerInfo m_aTimerInfo[TIMER_COUNT];
 136
 137 } tEplTimerHighReskInstance;
 138
 139 //---------------------------------------------------------------------------
 140 // local vars
 141 //---------------------------------------------------------------------------
 142
 143 static tEplTimerHighReskInstance EplTimerHighReskInstance_l;
 144
 145 //---------------------------------------------------------------------------
 146 // local function prototypes
 147 //---------------------------------------------------------------------------
 148
 149 enum hrtimer_restart EplTimerHighReskCallback(struct hrtimer *pTimer_p);
 150
 151 //=========================================================================//
 152 //                                                                         //
 153 //          P U B L I C   F U N C T I O N S                                //
 154 //                                                                         //
 155 //=========================================================================//
 156
 157 //---------------------------------------------------------------------------
 158 //
 159 // Function:    EplTimerHighReskInit()
 160 //
 161 // Description: initializes the high resolution timer module.
 162 //
 163 // Parameters:  void
 164 //
 165 // Return:      tEplKernel      = error code
 166 //
 167 // State:       not tested
 168 //
 169 //---------------------------------------------------------------------------
 170
 171 tEplKernel EplTimerHighReskInit(void)
 172 {
 173         tEplKernel Ret;
 174
 175         Ret = EplTimerHighReskAddInstance();
 176
 177         return Ret;
 178
 179 }
 180
 181 //---------------------------------------------------------------------------
 182 //
 183 // Function:    EplTimerHighReskAddInstance()
 184 //
 185 // Description: initializes the high resolution timer module.
 186 //
 187 // Parameters:  void
 188 //
 189 // Return:      tEplKernel      = error code
 190 //
 191 // State:       not tested
 192 //
 193 //---------------------------------------------------------------------------
 194
 195 tEplKernel EplTimerHighReskAddInstance(void)
 196 {
 197         tEplKernel Ret;
 198         unsigned int uiIndex;
 199
 200         Ret = kEplSuccessful;
 201
 202         EPL_MEMSET(&EplTimerHighReskInstance_l, 0,
 203                    sizeof(EplTimerHighReskInstance_l));
 204
 205         /*
 206          * Initialize hrtimer structures for all usable timers.
 207          */
 208         for (uiIndex = 0; uiIndex < TIMER_COUNT; uiIndex++) {
 209                 tEplTimerHighReskTimerInfo *pTimerInfo;
 210                 struct hrtimer *pTimer;
 211
 212                 pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[uiIndex];
 213                 pTimer = &pTimerInfo->m_Timer;
 214                 hrtimer_init(pTimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 215
 216                 pTimer->function = EplTimerHighReskCallback;
 217         }
 218
 219         return Ret;
 220 }
 221
 222 //---------------------------------------------------------------------------
 223 //
 224 // Function:    EplTimerHighReskDelInstance()
 225 //
 226 // Description: shuts down the high resolution timer module.
 227 //
 228 // Parameters:  void
 229 //
 230 // Return:      tEplKernel      = error code
 231 //
 232 // State:       not tested
 233 //
 234 //---------------------------------------------------------------------------
 235
 236 tEplKernel EplTimerHighReskDelInstance(void)
 237 {
 238         tEplTimerHighReskTimerInfo *pTimerInfo;
 239         tEplKernel Ret;
 240         unsigned int uiIndex;
 241
 242         Ret = kEplSuccessful;
 243
 244         for (uiIndex = 0; uiIndex < TIMER_COUNT; uiIndex++) {
 245                 pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[0];
 246                 pTimerInfo->m_pfnCallback = NULL;
 247                 pTimerInfo->m_EventArg.m_TimerHdl = 0;
 248                 /*
 249                  * In this case we can not just try to cancel the timer.
 250                  * We actually have to wait until its callback function
 251                  * has returned.
 252                  */
 253                 hrtimer_cancel(&pTimerInfo->m_Timer);
 254         }
 255
 256         return Ret;
 257
 258 }
 259
 260 //---------------------------------------------------------------------------
 261 //
 262 // Function:    EplTimerHighReskModifyTimerNs()
 263 //
 264 // Description: modifies the timeout of the timer with the specified handle.
 265 //              If the handle the pointer points to is zero, the timer must
 266 //              be created first.
 267 //              If it is not possible to stop the old timer,
 268 //              this function always assures that the old timer does not
 269 //              trigger the callback function with the same handle as the new
 270 //              timer. That means the callback function must check the passed
 271 //              handle with the one returned by this function. If these are
 272 //              unequal, the call can be discarded.
 273 //
 274 // Parameters:  pTimerHdl_p     = pointer to timer handle
 275 //              ullTimeNs_p     = relative timeout in [ns]
 276 //              pfnCallback_p   = callback function, which is called mutual
 277 //                                exclusive with the Edrv callback functions
 278 //                                (Rx and Tx).
 279 //              ulArgument_p    = user-specific argument
 280 //              fContinuously_p = if TRUE, callback function will be called
 281 //                                continuously;
 282 //                                otherwise, it is a oneshot timer.
 283 //
 284 // Return:      tEplKernel      = error code
 285 //
 286 // State:       not tested
 287 //
 288 //---------------------------------------------------------------------------
 289
 290 tEplKernel EplTimerHighReskModifyTimerNs(tEplTimerHdl *pTimerHdl_p,
 291                                          unsigned long long ullTimeNs_p,
 292                                          tEplTimerkCallback pfnCallback_p,
 293                                          unsigned long ulArgument_p,
 294                                          BOOL fContinuously_p)
 295 {
 296         tEplKernel Ret;
 297         unsigned int uiIndex;
 298         tEplTimerHighReskTimerInfo *pTimerInfo;
 299         ktime_t RelTime;
 300
 301         Ret = kEplSuccessful;
 302
 303         // check pointer to handle
 304         if (pTimerHdl_p == NULL) {
 305                 Ret = kEplTimerInvalidHandle;
 306                 goto Exit;
 307         }
 308
 309         if (*pTimerHdl_p == 0) {        // no timer created yet
 310
 311                 // search free timer info structure
 312                 pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[0];
 313                 for (uiIndex = 0; uiIndex < TIMER_COUNT;
 314                      uiIndex++, pTimerInfo++) {
 315                         if (pTimerInfo->m_EventArg.m_TimerHdl == 0) {   // free structure found
 316                                 break;
 317                         }
 318                 }
 319                 if (uiIndex >= TIMER_COUNT) {   // no free structure found
 320                         Ret = kEplTimerNoTimerCreated;
 321                         goto Exit;
 322                 }
 323
 324                 pTimerInfo->m_EventArg.m_TimerHdl = HDL_INIT(uiIndex);
 325         } else {
 326                 uiIndex = HDL_TO_IDX(*pTimerHdl_p);
 327                 if (uiIndex >= TIMER_COUNT) {   // invalid handle
 328                         Ret = kEplTimerInvalidHandle;
 329                         goto Exit;
 330                 }
 331
 332                 pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[uiIndex];
 333         }
 334
 335         /*
 336          * increment timer handle
 337          * (if timer expires right after this statement, the user
 338          * would detect an unknown timer handle and discard it)
 339          */
 340         pTimerInfo->m_EventArg.m_TimerHdl =
 341             HDL_INC(pTimerInfo->m_EventArg.m_TimerHdl);
 342         *pTimerHdl_p = pTimerInfo->m_EventArg.m_TimerHdl;
 343
 344         // reject too small time values
 345         if ((fContinuously_p && (ullTimeNs_p < TIMER_MIN_VAL_CYCLE))
 346             || (!fContinuously_p && (ullTimeNs_p < TIMER_MIN_VAL_SINGLE))) {
 347                 Ret = kEplTimerNoTimerCreated;
 348                 goto Exit;
 349         }
 350
 351         pTimerInfo->m_EventArg.m_ulArg = ulArgument_p;
 352         pTimerInfo->m_pfnCallback = pfnCallback_p;
 353         pTimerInfo->m_fContinuously = fContinuously_p;
 354         pTimerInfo->m_ullPeriod = ullTimeNs_p;
 355
 356         /*
 357          * HRTIMER_MODE_REL does not influence general handling of this timer.
 358          * It only sets relative mode for this start operation.
 359          * -> Expire time is calculated by: Now + RelTime
 360          * hrtimer_start also skips pending timer events.
 361          * The state HRTIMER_STATE_CALLBACK is ignored.
 362          * We have to cope with that in our callback function.
 363          */
 364         RelTime = ktime_add_ns(ktime_set(0, 0), ullTimeNs_p);
 365         hrtimer_start(&pTimerInfo->m_Timer, RelTime, HRTIMER_MODE_REL);
 366
 367       Exit:
 368         return Ret;
 369
 370 }
 371
 372 //---------------------------------------------------------------------------
 373 //
 374 // Function:    EplTimerHighReskDeleteTimer()
 375 //
 376 // Description: deletes the timer with the specified handle. Afterward the
 377 //              handle is set to zero.
 378 //
 379 // Parameters:  pTimerHdl_p     = pointer to timer handle
 380 //
 381 // Return:      tEplKernel      = error code
 382 //
 383 // State:       not tested
 384 //
 385 //---------------------------------------------------------------------------
 386
 387 tEplKernel EplTimerHighReskDeleteTimer(tEplTimerHdl *pTimerHdl_p)
 388 {
 389         tEplKernel Ret = kEplSuccessful;
 390         unsigned int uiIndex;
 391         tEplTimerHighReskTimerInfo *pTimerInfo;
 392
 393         // check pointer to handle
 394         if (pTimerHdl_p == NULL) {
 395                 Ret = kEplTimerInvalidHandle;
 396                 goto Exit;
 397         }
 398
 399         if (*pTimerHdl_p == 0) {        // no timer created yet
 400                 goto Exit;
 401         } else {
 402                 uiIndex = HDL_TO_IDX(*pTimerHdl_p);
 403                 if (uiIndex >= TIMER_COUNT) {   // invalid handle
 404                         Ret = kEplTimerInvalidHandle;
 405                         goto Exit;
 406                 }
 407                 pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[uiIndex];
 408                 if (pTimerInfo->m_EventArg.m_TimerHdl != *pTimerHdl_p) {        // invalid handle
 409                         goto Exit;
 410                 }
 411         }
 412
 413         *pTimerHdl_p = 0;
 414         pTimerInfo->m_EventArg.m_TimerHdl = 0;
 415         pTimerInfo->m_pfnCallback = NULL;
 416
 417         /*
 418          * Three return cases of hrtimer_try_to_cancel have to be tracked:
 419          *  1 - timer has been removed
 420          *  0 - timer was not active
 421          *      We need not do anything. hrtimer timers just consist of
 422          *      a hrtimer struct, which we might enqueue in the hrtimers
 423          *      event list by calling hrtimer_start().
 424          *      If a timer is not enqueued, it is not present in hrtimers.
 425          * -1 - callback function is running
 426          *      In this case we have to ensure that the timer is not
 427          *      continuously restarted. This has been done by clearing
 428          *      its handle.
 429          */
 430         hrtimer_try_to_cancel(&pTimerInfo->m_Timer);
 431
 432       Exit:
 433         return Ret;
 434
 435 }
 436
 437 //---------------------------------------------------------------------------
 438 //
 439 // Function:    EplTimerHighReskCallback()
 440 //
 441 // Description: Callback function commonly used for all timers.
 442 //
 443 // Parameters:  pTimer_p = pointer to hrtimer
 444 //
 445 // Return:
 446 //
 447 // State:       not tested
 448 //
 449 //---------------------------------------------------------------------------
 450
 451 enum hrtimer_restart EplTimerHighReskCallback(struct hrtimer *pTimer_p)
 452 {
 453         unsigned int uiIndex;
 454         tEplTimerHighReskTimerInfo *pTimerInfo;
 455         tEplTimerHdl OrgTimerHdl;
 456         enum hrtimer_restart Ret;
 457
 458         BENCHMARK_MOD_24_SET(4);
 459
 460         Ret = HRTIMER_NORESTART;
 461         pTimerInfo =
 462             container_of(pTimer_p, tEplTimerHighReskTimerInfo, m_Timer);
 463         uiIndex = HDL_TO_IDX(pTimerInfo->m_EventArg.m_TimerHdl);
 464         if (uiIndex >= TIMER_COUNT) {   // invalid handle
 465                 goto Exit;
 466         }
 467
 468         /*
 469          * We store the timer handle before calling the callback function
 470          * as the timer can be modified inside it.
 471          */
 472         OrgTimerHdl = pTimerInfo->m_EventArg.m_TimerHdl;
 473
 474         if (pTimerInfo->m_pfnCallback != NULL) {
 475                 pTimerInfo->m_pfnCallback(&pTimerInfo->m_EventArg);
 476         }
 477
 478         if (pTimerInfo->m_fContinuously) {
 479                 ktime_t Interval;
 480 #ifdef PROVE_OVERRUN
 481                 ktime_t Now;
 482                 unsigned long Overruns;
 483 #endif
 484
 485                 if (OrgTimerHdl != pTimerInfo->m_EventArg.m_TimerHdl) {
 486                         /* modified timer has already been restarted */
 487                         goto Exit;
 488                 }
 489 #ifdef PROVE_OVERRUN
 490                 Now = ktime_get();
 491                 Interval =
 492                     ktime_add_ns(ktime_set(0, 0), pTimerInfo->m_ullPeriod);
 493                 Overruns = hrtimer_forward(pTimer_p, Now, Interval);
 494                 if (Overruns > 1) {
 495                         printk
 496                             ("EplTimerHighResk: Continuous timer (handle 0x%lX) had to skip %lu interval(s)!\n",
 497                              pTimerInfo->m_EventArg.m_TimerHdl, Overruns - 1);
 498                 }
 499 #else
 500                 pTimer_p->expires = ktime_add_ns(pTimer_p->expires,
 501                                                  pTimerInfo->m_ullPeriod);
 502 #endif
 503
 504                 Ret = HRTIMER_RESTART;
 505         }
 506
 507       Exit:
 508         BENCHMARK_MOD_24_RESET(4);
 509         return Ret;
 510 }