sdm/libs/hwc/cpuhint.cpp

/* Copyright (c) 2015, The Linux Foundataion. All rights reserved.
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* modification, are permitted provided that the following conditions are
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*       notice, this list of conditions and the following disclaimer.
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*       with the distribution.
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*       from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
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#include <cutils/properties.h>
#include <dlfcn.h>

#include "cpuhint.h"
#include "hwc_debugger.h"

#define __CLASS__ "CPUHint"

namespace sdm {

CPUHint::~CPUHint() {
  if (lib_handle_) {
    dlclose(lib_handle_);
    lib_handle_ = NULL;
  }
}

DisplayError CPUHint::Init(HWCDebugHandler *debug_handler) {
  char path[PROPERTY_VALUE_MAX];
  if (debug_handler->GetProperty("ro.vendor.extension_library", path) != kErrorNone) {
    DLOGI("Vendor Extension Library not enabled");
    return kErrorNotSupported;
  }

  int pre_enable_window = -1;
  debug_handler->GetProperty("sdm.perf_hint_window", &pre_enable_window);
  if (pre_enable_window <= 0) {
    DLOGI("Invalid CPU Hint Pre-enable Window %d", pre_enable_window);
    return kErrorNotSupported;
  }

  DLOGI("CPU Hint Pre-enable Window %d", pre_enable_window);
  pre_enable_window_ = pre_enable_window;
  lib_handle_ = dlopen(path, RTLD_NOW);

  if (lib_handle_) {
    *(reinterpret_cast<void **>(&fn_lock_acquire_)) = dlsym(lib_handle_, "perf_lock_acq");
    *(reinterpret_cast<void **>(&fn_lock_release_)) = dlsym(lib_handle_, "perf_lock_rel");
    if (!fn_lock_acquire_ || !fn_lock_release_) {
      DLOGW("Failed to load symbols for Vendor Extension Library");
      return kErrorNotSupported;
    }
    DLOGI("Successfully Loaded Vendor Extension Library symbols");
    enabled_ = true;
  } else {
    DLOGW("Failed to open %s : %s", path, dlerror());
  }

  return kErrorNone;
}

void CPUHint::Set() {
  if (!enabled_) {
    return;
  }
  if (lock_acquired_) {
    return;
  }
  if (frame_countdown_) {
    --frame_countdown_;
    return;
  }

  int hint = HINT;
  lock_handle_ = fn_lock_acquire_(0 /*handle*/, 0/*duration*/,
                                  &hint, sizeof(hint) / sizeof(int));
  if (lock_handle_ >= 0) {
    lock_acquired_ = true;
  }
}

void CPUHint::Reset() {
  if (!enabled_) {
    return;
  }

  frame_countdown_ = pre_enable_window_;

  if (!lock_acquired_) {
    return;
  }

  fn_lock_release_(lock_handle_);
  lock_acquired_ = false;
}

}  // namespace sdm