#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0
import argparse
import re
import shutil
import subprocess
import sys
import os

script = os.path.relpath(__file__)

DESCRIPTION = f"""
For Intel CPUs, update the microcode revisions that determine
X86_BUG_OLD_MICROCODE.

This script is intended to be run in response to releases of the
official Intel microcode GitHub repository:
https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files.git

It takes the Intel microcode files as input and uses iucode-tool to
extract the revision information. It prints the output in the format
expected by intel-ucode-defs.h.

Usage:
    ./{script} /path/to/microcode/files > /path/to/intel-ucode-defs.h

Typically, someone at Intel would see a new public release, wait for at
least three months to ensure the update is stable, run this script to
refresh the intel-ucode-defs.h file, and send a patch upstream to update
the mainline and stable versions.

Any exception to this process should be supported with an appropriate
justification.
"""

SIG_RE = re.compile(r'sig (0x[0-9a-fA-F]+)')
PFM_RE = re.compile(r'pf_mask (0x[0-9a-fA-F]+)')
REV_RE = re.compile(r'rev (0x[0-9a-fA-F]+)')

# Functions to extract family, model, and stepping
def bits(val, bottom, top):
    mask = (1 << (top + 1 - bottom)) - 1
    return (val >> bottom) & mask

def family(sig):
    if bits(sig, 8, 11) == 0xf:
        return bits(sig, 8, 11) + bits(sig, 20, 27)
    return bits(sig, 8, 11)

def model(sig):
    return bits(sig, 4, 7) | (bits(sig, 16, 19) << 4)

def step(sig):
    return bits(sig, 0, 3)

class Ucode:
    def __init__(self, sig, pfm, rev):
        self.family = family(sig)
        self.model = model(sig)
        self.steppings = 1 << step(sig)
        self.platforms = pfm
        self.rev = rev

        self.key = (self.family, self.model, self.steppings, self.platforms)

    def __eq__(self, other):
        return self.key == other.key

    def __hash__(self):
        return hash(self.key)

    def __str__(self):
        return "{ .flags = X86_CPU_ID_FLAG_ENTRY_VALID, .vendor = X86_VENDOR_INTEL, .family = 0x%x, .model = 0x%02x, .steppings = 0x%04x, .platform_mask = 0x%02x, .driver_data = 0x%x }," % \
                (self.family, self.model, self.steppings, self.platforms, self.rev)

def main():
    parser = argparse.ArgumentParser(description=DESCRIPTION,
                                     formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument('ucode_files', nargs='+', help='Path(s) to the microcode files')

    args = parser.parse_args()

    # Process the microcode files using iucode-tool
    iucode_tool = shutil.which("iucode-tool") or shutil.which("iucode_tool")
    if iucode_tool is None:
        print("Error: iucode-tool not found, please install it", file=sys.stderr)
        sys.exit(1)

    cmd = [iucode_tool, '--list-all'] + args.ucode_files

    result = subprocess.run(cmd, capture_output=True, text=True)
    if result.returncode != 0:
        print("Error: iucode-tool ran into an error, exiting", file=sys.stderr)
        if result.stderr:
            print(result.stderr, file=sys.stderr, end='')
        sys.exit(1)

    ucodes = set()

    # Parse the output of iucode-tool
    for line in result.stdout.splitlines():
        sig_match = SIG_RE.search(line)
        pfm_match = PFM_RE.search(line)
        rev_match = REV_RE.search(line)

        if not (sig_match and pfm_match and rev_match):
            continue

        sig = int(sig_match.group(1), 16)
        pfm = int(pfm_match.group(1), 16)
        rev = int(rev_match.group(1), 16)
        debug_rev = bits(rev, 31, 31)
        if debug_rev != 0:
            print("Error: Debug ucode file found, exiting", file=sys.stderr)
            sys.exit(1)

        ucodes.add(Ucode(sig, pfm, rev))

    if not ucodes:
        print("Error: No valid microcode files found, exiting", file=sys.stderr)
        sys.exit(1)

    # Sort and print the microcode entries
    print("/* SPDX-License-Identifier: GPL-2.0 */")
    print("/* Auto-generated by scripts/update-intel-ucode-defs.py */")
    for u in sorted(ucodes, key=lambda x: x.key):
        print(u)

if __name__ == "__main__":
    main()