# Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import glob, logging, os, re
from autotest_lib.client.bin import test, utils
from autotest_lib.client.common_lib import error
from autotest_lib.client.cros import power_status


# Specify registers to check.  The format needs to be:
#   register offset : ('bits', 'expression')
DMI_BAR_CHECKS = {
    '0x88':  [('1:0', 3)],
    '0x200': [('27:26', 0)],
    '0x210': [('2:0', 1), ('15:8', 1)],
    '0xc28': [('5:1', 7)],
    '0xc2e': [('5', 1)],
    '0xc30': [('11', 0), ('10:8', 4)],
    '0xc34': [('9:4', 7), ('0', 1)],
}

MCH_BAR_CHECKS = {}

MSR_CHECKS = {
    '0xe2':  [('7', 0), ('2:0', 4)],
    '0x198': [('28:24', 6)],
    '0x1a0': [('33:32', 3), ('26:25', 3), ('16', 1)],
}

# Give an ASPM exception for these PCI devices. ID is taken from lspci -n.
ASPM_EXCEPTED_DEVICES = [
    '8086:27d8'  # Intel Corporation 82801G High Definition Audio Controller
]


class power_x86Settings(test.test):
    version = 1

    def run_once(self):
        if not self._check_cpu_type():
            raise error.TestNAError('Unsupported CPU')

        self._rdmsr_cmd = 'iotools rdmsr 0'
        self._pci_read32_cmd = 'iotools pci_read32'
        self._mmio_read32_cmd = 'iotools mmio_read32'

        status = power_status.get_status()
        if status.linepower[0].online:
            logging.info('AC Power is online')
            self._on_ac = True
        else:
            logging.info('AC Power is offline')
            self._on_ac = False

        failures = ''

        fail_count = self._verify_dmi_bar()
        if fail_count:
            failures += 'dmi_failures(%d) ' % fail_count

        fail_count = self._verify_mch_bar()
        if fail_count:
            failures += 'mch_failures(%d) ' % fail_count

        fail_count = self._verify_msrs()
        if fail_count:
            failures += 'msr_failures(%d) ' % fail_count

        fail_count = self._verify_pcie_aspm()
        if fail_count:
            failures += 'pcie_aspm_failures(%d) ' % fail_count

        fail_count = self._verify_wifi_power_settings()
        if fail_count:
            failures += 'wifi_failures(%d) ' % fail_count

        fail_count = self._verify_usb_power_settings()
        if fail_count:
            failures += 'usb_failures(%d) ' % fail_count

        fail_count = self._verify_storage_power_settings()
        if fail_count:
            failures += 'storage_failures(%d) ' % fail_count

        fail_count = self._verify_audio_power_settings()
        if fail_count:
            failures += 'audio_failures(%d) ' % fail_count

        if failures:
            raise error.TestFail(failures)


    def _check_cpu_type(self):
        cpuinfo = utils.read_file('/proc/cpuinfo')

        # Look for Intel Atom N4xx or N5xx series CPUs
        match = re.search(r'Intel.*Atom.*N[45]', cpuinfo)
        if match:
            return True

        logging.info(cpuinfo)
        return False


    def _verify_wifi_power_settings(self):
        if self._on_ac:
            expected_state = 'off'
        else:
            expected_state = 'on'

        iwconfig_out = utils.system_output('iwconfig', retain_output=True)
        match = re.search(r'Power Management:(.*)', iwconfig_out)
        if match and match.group(1) == expected_state:
            return 0

        logging.info(iwconfig_out)
        return 1


    def _verify_storage_power_settings(self):
        if self._on_ac:
            return 0

        expected_state = 'min_power'

        dirs_path = '/sys/class/scsi_host/host*'
        dirs = glob.glob(dirs_path)
        if not dirs:
            logging.info('scsi_host paths not found')
            return 1

        for dir in dirs:
            link_policy_file = os.path.join(dir,
                                            'link_power_management_policy')
            if not os.path.exists(link_policy_file):
                logging.debug('path does not exist: %s', link_policy_file)
                continue

            out = utils.read_one_line(link_policy_file)
            logging.debug('storage: path set to %s for %s',
                           out, link_policy_file)
            if out == expected_state:
                return 0

        return 1


    def _verify_usb_power_settings(self):
        if self._on_ac:
            expected_state = 'on'
        else:
            expected_state = 'auto'

        dirs_path = '/sys/bus/usb/devices/*/power'
        dirs = glob.glob(dirs_path)
        if not dirs:
            logging.info('USB power path not found')
            return 1

        errors = 0
        for dir in dirs:
            level_file = os.path.join(dir, 'level')
            if not os.path.exists(level_file):
                logging.info('USB: power level file not found for %s', dir)
                continue

            out = utils.read_one_line(level_file)
            logging.debug('USB: path set to %s for %s',
                           out, level_file)
            if out != expected_state:
                logging.info(level_file)
                errors += 1

        return errors


    def _verify_audio_power_settings(self):
        path = '/sys/module/snd_hda_intel/parameters/power_save'
        out = utils.read_one_line(path)
        logging.debug('Audio: %s = %s', path, out)

        # Make sure that power_save parameter is set to a non-zero value
        if int(out):
            return 0

        return 1


    def _verify_pcie_aspm(self):
        errors = 0
        out = utils.system_output('lspci -n')
        for line in out.splitlines():
            slot, _, id = line.split()[0:3]
            slot_out = utils.system_output('lspci -s %s -vv' % slot,
                                            retain_output=True)
            match = re.search(r'LnkCtl:(.*);', slot_out)
            if match:
                if id in ASPM_EXCEPTED_DEVICES:
                    continue

                split = match.group(1).split()
                if split[1] == 'Disabled' or \
                   (split[2] == 'Enabled' and split[1] != 'L1'):
                    errors += 1
                    logging.info(slot_out)
            else:
                logging.info('PCIe: LnkCtl not found for %s', line)

        return errors


    def _verify_dmi_bar(self):
        # DMIBAR is at offset 0x68 of B/D/F 0/0/0
        cmd = '%s 0 0 0 0x68' % (self._pci_read32_cmd)
        self._dmi_bar = int(utils.system_output(cmd), 16) & 0xfffffffe
        logging.debug('DMI BAR is %s', hex(self._dmi_bar))

        return self._verify_registers('dmi', self._read_dmi_bar,
                                      DMI_BAR_CHECKS)


    def _verify_mch_bar(self):
        # MCHBAR is at offset 0x48 of B/D/F 0/0/0
        cmd = '%s 0 0 0 0x48' % (self._pci_read32_cmd)
        self._mch_bar = int(utils.system_output(cmd), 16) & 0xfffffffe
        logging.debug('MCH BAR is %s', hex(self._mch_bar))

        return self._verify_registers('mch', self._read_mch_bar,
                                       MCH_BAR_CHECKS)


    def _verify_msrs(self):
        return self._verify_registers('msr', self._read_msr, MSR_CHECKS)


    def _verify_registers(self, type, read_fn, match_list):
        errors = 0
        for k, v in match_list.iteritems():
            r = read_fn(k)
            for item in v:
                good = self._shift_mask_match(r, item)
                if not good:
                    logging.info('%s: reg = %s value = %s match = %s',
                                  type, k, hex(r), v)
                    errors += 1
        return errors


    def _shift_mask_match(self, value, match):
        expr = match[1]
        bits = match[0].split(':')
        hi_bit = int(bits[0])
        if len(bits) == 2:
            lo_bit = int(bits[1])
        else:
            lo_bit = int(bits[0])

        value >>= lo_bit
        mask = (1 << (hi_bit - lo_bit + 1)) - 1
        value &= mask

        good = (value == expr)
        if not good:
            logging.info('FAILED: bits = %s value = %s mask = %s expr = %s',
                          bits, hex(value), mask, expr)
        return good


    def _read_dmi_bar(self, offset):
        return self._read_mmio_read32(self._dmi_bar + int(offset, 16))


    def _read_mch_bar(self, offset):
        return self._read_mmio_read32(self._mch_bar + int(offset, 16))


    def _read_mmio_read32(self, address):
        cmd = '%s %s' % (self._mmio_read32_cmd, address)
        return int(utils.system_output(cmd), 16)


    def _read_msr(self, register):
        cmd = '%s %s' % (self._rdmsr_cmd, register)
        return int(utils.system_output(cmd), 16)