avocado.utils: Add cpu module

Add utility functions to list and get information about
the CPUs present in a testing machine.
Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>

avocado/utils/cpu.py

+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+#
+# See LICENSE for more details.
+#
+# This code was inspired in the autotest project,
+#
+# client/base_utils.py
+# Original author: Martin J Bligh <mbligh@google.com>
+# Original author: John Admanski <jadmanski@google.com>
+
+
+"""
+Get information from the current's machine CPU.
+"""
+
+import re
+
+
+def _list_matches(lst, pattern):
+    """
+    True if any item in list matches the specified pattern.
+    """
+    compiled = re.compile(pattern)
+    for element in lst:
+        match = compiled.search(element)
+        if match:
+            return 1
+    return 0
+
+
+def _get_cpu_info():
+    """
+    Reads /proc/cpuinfo and returns a list of file lines
+
+    :returns: `list` of lines from /proc/cpuinfo file
+    :rtype: `list`
+    """
+    with open('/proc/cpuinfo', 'r') as f:
+        cpuinfo = f.readlines()
+    return cpuinfo
+
+
+def cpu_has_flags(flags):
+    """
+    Check if a list of flags are available on current CPU info
+
+    :param flags: A `list` of cpu flags that must exists on the current CPU.
+    :type flags: `list`
+    :returns: `bool` True if all the flags were found or False if not
+    :rtype: `list`
+    """
+    cpu_info = _get_cpu_info()
+
+    if not isinstance(flags, list):
+        flags = [flags]
+
+    for flag in flags:
+        if not _list_matches(cpu_info, '.*%s.*' % flag):
+            return False
+    return True
+
+
+def get_cpu_vendor_name():
+    """
+    Get the current cpu vendor name
+
+    :returns: string 'intel' or 'amd' or 'power7' depending on the current CPU architecture.
+    :rtype: `string`
+    """
+    vendors_map = {
+        'intel': ("GenuineIntel", ),
+        'amd': ("AMD", ),
+        'power7': ("POWER7", )
+    }
+
+    cpu_info = _get_cpu_info()
+    for vendor, identifiers in vendors_map.items():
+        for identifier in identifiers:
+            if _list_matches(cpu_info, identifier):
+                return vendor
+    return None
+
+
+def get_cpu_arch():
+    """
+    Work out which CPU architecture we're running on
+    """
+    cpuinfo = _get_cpu_info()
+
+    if _list_matches(cpuinfo, '^cpu.*(RS64|POWER3|Broadband Engine)'):
+        return 'power'
+    elif _list_matches(cpuinfo, '^cpu.*POWER4'):
+        return 'power4'
+    elif _list_matches(cpuinfo, '^cpu.*POWER5'):
+        return 'power5'
+    elif _list_matches(cpuinfo, '^cpu.*POWER6'):
+        return 'power6'
+    elif _list_matches(cpuinfo, '^cpu.*POWER7'):
+        return 'power7'
+    elif _list_matches(cpuinfo, '^cpu.*POWER8'):
+        return 'power8'
+    elif _list_matches(cpuinfo, '^cpu.*PPC970'):
+        return 'power970'
+    elif _list_matches(cpuinfo, 'ARM'):
+        return 'arm'
+    elif _list_matches(cpuinfo, '^flags.*:.* lm .*'):
+        return 'x86_64'
+    else:
+        return 'i386'