Quelle  intel_scheduler_helpers.c   Sprache: C

// SPDX-License-Identifier: MIT
/*
 * Copyright © 2021 Intel Corporation
 */

#include <linux/jiffies.h>

//#include "gt/intel_engine_user.h"
#include "gt/intel_gt.h"
#include "i915_drv.h"
#include "i915_selftest.h"

#include "selftests/intel_scheduler_helpers.h"

#define REDUCED_TIMESLICE 5
#define REDUCED_PREEMPT  10
#define WAIT_FOR_RESET_TIME_MS 10000

struct intel_engine_cs *intel_selftest_find_any_engine(struct intel_gt *gt)
{
 struct intel_engine_cs *engine;
 enum intel_engine_id id;

 for_each_engine(engine, gt, id)
  return engine;

 pr_err("No valid engine found!\n");
 return NULL;
}

int intel_selftest_modify_policy(struct intel_engine_cs *engine,
     struct intel_selftest_saved_policy *saved,
     enum selftest_scheduler_modify modify_type)
{
 int err;

 saved->reset = engine->i915->params.reset;
 saved->flags = engine->flags;
 saved->timeslice = engine->props.timeslice_duration_ms;
 saved->preempt_timeout = engine->props.preempt_timeout_ms;

 switch (modify_type) {
 case SELFTEST_SCHEDULER_MODIFY_FAST_RESET:
  /*
 * Enable force pre-emption on time slice expiration
 * together with engine reset on pre-emption timeout.
 * This is required to make the GuC notice and reset
 * the single hanging context.
 * Also, reduce the preemption timeout to something
 * small to speed the test up.
 */
  engine->i915->params.reset = 2;
  engine->flags |= I915_ENGINE_WANT_FORCED_PREEMPTION;
  engine->props.timeslice_duration_ms = REDUCED_TIMESLICE;
  engine->props.preempt_timeout_ms = REDUCED_PREEMPT;
  break;

 case SELFTEST_SCHEDULER_MODIFY_NO_HANGCHECK:
  engine->props.preempt_timeout_ms = 0;
  break;

 default:
  pr_err("Invalid scheduler policy modification type: %d!\n", modify_type);
  return -EINVAL;
 }

 if (!intel_engine_uses_guc(engine))
  return 0;

 err = intel_guc_global_policies_update(&engine->gt->uc.guc);
 if (err)
  intel_selftest_restore_policy(engine, saved);

 return err;
}

int intel_selftest_restore_policy(struct intel_engine_cs *engine,
      struct intel_selftest_saved_policy *saved)
{
 /* Restore the original policies */
 engine->i915->params.reset = saved->reset;
 engine->flags = saved->flags;
 engine->props.timeslice_duration_ms = saved->timeslice;
 engine->props.preempt_timeout_ms = saved->preempt_timeout;

 if (!intel_engine_uses_guc(engine))
  return 0;

 return intel_guc_global_policies_update(&engine->gt->uc.guc);
}

int intel_selftest_wait_for_rq(struct i915_request *rq)
{
 long ret;

 ret = i915_request_wait(rq, 0, msecs_to_jiffies(WAIT_FOR_RESET_TIME_MS));
 if (ret < 0)
  return ret;

 return 0;
}