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/*

(C) Copyright IBM Corp. 2008

All rights reserved.

Redistribution and use in source and binary forms, with or without

modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice,

this list of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright

notice, this list of conditions and the following disclaimer in the

documentation and/or other materials provided with the distribution.

* Neither the name of IBM nor the names of its contributors may be

used to endorse or promote products derived from this software without

specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

POSSIBILITY OF SUCH DAMAGE.

*/

/* SPU timer start and alloc library services.  */

#include <spu_timer.h>

#include "spu_timer_internal.h"

/* The timers.  */

spu_timer_t __spu_timers[SPU_TIMER_NTIMERS] __attribute__ ((aligned (16)));

/* Active timer list.  */

spu_timer_t *__spu_timers_active;

/* Stopped (allocated) timer list.  */

spu_timer_t *__spu_timers_stopped;

/* List of timers being handled.  */

spu_timer_t *__spu_timers_handled;

/* Bitmask of available timers.  */

unsigned __spu_timers_avail =

  ((1 << (SPU_TIMER_NTIMERS - 1)) + ((1 << (SPU_TIMER_NTIMERS - 1)) - 1));

/* Allocates an SPU interval timer and returns the timer ID. Must be called

   before starting a timer. interval specifies the expiration interval in

   timebase units. func specifies the function pointer to expiration handler.

   Returns the timer ID on success or <0 on Failure:

    * SPU_TIMER_ERR_NONE_FREE - no free timers to allocate

    * SPU_TIMER_ERR_INVALID_PARM - invalid parm  */

int

spu_timer_alloc (int interval, void (*func) (int))

{

  unsigned was_enabled;

  int id;

  if (interval < MIN_INTVL || interval > MAX_INTVL || func == NULL)

    return SPU_TIMER_ERR_INVALID_PARM;

  was_enabled = spu_readch (SPU_RdMachStat) & 0x1;

  /* Get id of next available timer.  */

  id = spu_extract ((spu_sub ((unsigned) 31,

                                  spu_cntlz (spu_promote

                                             (__spu_timers_avail, 0)))), 0);

  /* No timers avail.  */

  if (id == -1)

    return SPU_TIMER_ERR_NONE_FREE;

  /* Higher order bits represent lower timer ids.  */

  __spu_timers_avail &= ~(1 << (id));

  id = (SPU_TIMER_NTIMERS - 1) - id;

  /* Initialize timer and put it on stopped list.  */

  (__spu_timers + id)->func = func;

  (__spu_timers + id)->intvl = interval;

  (__spu_timers + id)->id = id;

  (__spu_timers + id)->state = SPU_TIMER_STOPPED;

  spu_idisable ();

  (__spu_timers + id)->next = __spu_timers_stopped;

  __spu_timers_stopped = &__spu_timers[id];

  if (__likely (was_enabled))

    spu_ienable ();

  return id;

}

/* External interface for starting a timer.  See description of

   __spu_timer_start(). Returns 0 on success and <0 on failure:

    * SPU_TIMER_ERR_INVALID_ID - invalid id

    * SPU_TIMER_ERR_NOCLOCK - clock is off

    * SPU_TIMER_ERR_NOT_STOPPED - timer not in stopped state  */

int

spu_timer_start (int id)

{

  if (id < 0 || id >= SPU_TIMER_NTIMERS)

    return SPU_TIMER_ERR_INVALID_ID;

  if (__spu_clock_startcnt == 0)

    return SPU_TIMER_ERR_NOCLOCK;

  if (__spu_timers[id].state != SPU_TIMER_STOPPED)

    return SPU_TIMER_ERR_NOT_STOPPED;

  __spu_timer_start (id, 1);

  return 0;

}