1/*
2**
3** Copyright 2015, The Android Open Source Project
4**
5** Licensed under the Apache License, Version 2.0 (the "License");
6** you may not use this file except in compliance with the License.
7** You may obtain a copy of the License at
8**
9**     http://www.apache.org/licenses/LICENSE-2.0
10**
11** Unless required by applicable law or agreed to in writing, software
12** distributed under the License is distributed on an "AS IS" BASIS,
13** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14** See the License for the specific language governing permissions and
15** limitations under the License.
16*/
17
18#include <stdio.h>
19#include <stdlib.h>
20#include <string.h>
21#include <unistd.h>
22#include <string>
23#include <sstream>
24#include <sys/types.h>
25#include <sys/wait.h>
26
27#include <cutils/properties.h>
28
29#include "cpuconfig.h"
30#include "perfprofdutils.h"
31
32#define SYSFSCPU "/sys/devices/system/cpu"
33
34HardwireCpuHelper::HardwireCpuHelper(bool perform)
35    : mpdecision_stopped_(false)
36{
37  if (perform && GetMpdecisionRunning()) {
38    mpdecision_stopped_ = true;
39    StopMpdecision();
40    int ncores = GetNumCores();
41    for (int i = 0; i < ncores; ++i) {
42      OnlineCore(i, 1);
43    }
44  }
45}
46
47HardwireCpuHelper::~HardwireCpuHelper()
48{
49  if (mpdecision_stopped_) {
50    RestartMpdecision();
51  }
52}
53
54bool HardwireCpuHelper::GetMpdecisionRunning()
55{
56  char propBuf[PROPERTY_VALUE_MAX];
57  property_get("init.svc.mpdecision", propBuf, "");
58  return strcmp(propBuf, "running") == 0;
59}
60
61
62int HardwireCpuHelper::GetNumCores()
63{
64  int ncores = -1;
65  std::string possible(SYSFSCPU "/possible");
66  FILE *fp = fopen(possible.c_str(), "re");
67  if (fp) {
68    unsigned lo = 0, hi = 0;
69    if (fscanf(fp, "%u-%u", &lo, &hi) == 2) {
70      ncores = hi - lo + 1;
71    }
72    fclose(fp);
73  }
74  return ncores;
75}
76
77void HardwireCpuHelper::OnlineCore(int i, int onoff)
78{
79  std::stringstream ss;
80  ss << SYSFSCPU "/cpu" << i << "/online";
81  FILE *fp = fopen(ss.str().c_str(), "we");
82  if (fp) {
83    fprintf(fp, onoff ? "1\n" : "0\n");
84    fclose(fp);
85  } else {
86    W_ALOGW("open failed for %s", ss.str().c_str());
87  }
88}
89
90void HardwireCpuHelper::StopMpdecision()
91{
92  if (property_set("ctl.stop", "mpdecision")) {
93    W_ALOGE("setprop ctl.stop mpdecision failed");
94  }
95}
96
97void HardwireCpuHelper::RestartMpdecision()
98{
99  // Don't try to offline the cores we previously onlined -- let
100  // mpdecision figure out what to do
101
102  if (property_set("ctl.start", "mpdecision")) {
103    W_ALOGE("setprop ctl.start mpdecision failed");
104  }
105}
106