crypto: ccp - Add a sample python script for Dynamic Boost Control

Dynamic Boost Control commands are triggered by userspace with
an IOCTL interface that userspace will prepare proper buffers
for a request.

To allow prototyping and testing this interface, add a python3
command line script that loads the dbc_library.so for utilizing
the IOCTLs.

The signature to use and UID are passed as arguments to this script.
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

tools/crypto/ccp/.gitignore

+__pycache__

tools/crypto/ccp/dbc.py

+#!/usr/bin/python3
+# SPDX-License-Identifier: GPL-2.0
+
+import ctypes
+import os
+
+DBC_UID_SIZE = 16
+DBC_NONCE_SIZE = 16
+DBC_SIG_SIZE = 32
+
+PARAM_GET_FMAX_CAP = (0x3,)
+PARAM_SET_FMAX_CAP = (0x4,)
+PARAM_GET_PWR_CAP = (0x5,)
+PARAM_SET_PWR_CAP = (0x6,)
+PARAM_GET_GFX_MODE = (0x7,)
+PARAM_SET_GFX_MODE = (0x8,)
+PARAM_GET_CURR_TEMP = (0x9,)
+PARAM_GET_FMAX_MAX = (0xA,)
+PARAM_GET_FMAX_MIN = (0xB,)
+PARAM_GET_SOC_PWR_MAX = (0xC,)
+PARAM_GET_SOC_PWR_MIN = (0xD,)
+PARAM_GET_SOC_PWR_CUR = (0xE,)
+
+DEVICE_NODE = "/dev/dbc"
+
+lib = ctypes.CDLL("./dbc_library.so", mode=ctypes.RTLD_GLOBAL)
+
+
+def handle_error(code):
+    val = code * -1
+    raise OSError(val, os.strerror(val))
+
+
+def get_nonce(device, signature):
+    if not device:
+        raise ValueError("Device required")
+    buf = ctypes.create_string_buffer(DBC_NONCE_SIZE)
+    ret = lib.get_nonce(device.fileno(), ctypes.byref(buf), signature)
+    if ret:
+        handle_error(ret)
+    return buf.value
+
+
+def set_uid(device, new_uid, signature):
+    if not signature:
+        raise ValueError("Signature required")
+    if not new_uid:
+        raise ValueError("UID required")
+    ret = lib.set_uid(device.fileno(), new_uid, signature)
+    if ret:
+        handle_error(ret)
+    return True
+
+
+def process_param(device, message, signature, data=None):
+    if not signature:
+        raise ValueError("Signature required")
+    if type(message) != tuple:
+        raise ValueError("Expected message tuple")
+    arg = ctypes.c_int(data if data else 0)
+    ret = lib.process_param(device.fileno(), message[0], signature, ctypes.pointer(arg))
+    if ret:
+        handle_error(ret)
+    return arg, signature

tools/crypto/ccp/dbc_cli.py

+#!/usr/bin/python3
+# SPDX-License-Identifier: GPL-2.0
+import argparse
+import binascii
+import os
+import errno
+from dbc import *
+
+ERRORS = {
+    errno.EACCES: "Access is denied",
+    errno.E2BIG: "Excess data provided",
+    errno.EINVAL: "Bad parameters",
+    errno.EAGAIN: "Bad state",
+    errno.ENOENT: "Not implemented or message failure",
+    errno.EBUSY: "Busy",
+    errno.ENFILE: "Overflow",
+    errno.EPERM: "Signature invalid",
+}
+
+messages = {
+    "get-fmax-cap": PARAM_GET_FMAX_CAP,
+    "set-fmax-cap": PARAM_SET_FMAX_CAP,
+    "get-power-cap": PARAM_GET_PWR_CAP,
+    "set-power-cap": PARAM_SET_PWR_CAP,
+    "get-graphics-mode": PARAM_GET_GFX_MODE,
+    "set-graphics-mode": PARAM_SET_GFX_MODE,
+    "get-current-temp": PARAM_GET_CURR_TEMP,
+    "get-fmax-max": PARAM_GET_FMAX_MAX,
+    "get-fmax-min": PARAM_GET_FMAX_MIN,
+    "get-soc-power-max": PARAM_GET_SOC_PWR_MAX,
+    "get-soc-power-min": PARAM_GET_SOC_PWR_MIN,
+    "get-soc-power-cur": PARAM_GET_SOC_PWR_CUR,
+}
+
+
+def _pretty_buffer(ba):
+    return str(binascii.hexlify(ba, " "))
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(
+        description="Dynamic Boost control command line interface"
+    )
+    parser.add_argument(
+        "command",
+        choices=["get-nonce", "get-param", "set-param", "set-uid"],
+        help="Command to send",
+    )
+    parser.add_argument("--device", default="/dev/dbc", help="Device to operate")
+    parser.add_argument("--signature", help="File containing signature for command")
+    parser.add_argument("--message", choices=messages.keys(), help="Message index")
+    parser.add_argument("--data", help="Argument to pass to message")
+    parser.add_argument("--uid", help="File containing UID to pass")
+    return parser.parse_args()
+
+
+def pretty_error(code):
+    if code in ERRORS:
+        print(ERRORS[code])
+    else:
+        print("failed with return code %d" % code)
+
+
+if __name__ == "__main__":
+    args = parse_args()
+    data = 0
+    sig = None
+    uid = None
+    if not os.path.exists(args.device):
+        raise IOError("Missing device {device}".format(device=args.device))
+    if args.signature:
+        if not os.path.exists(args.signature):
+            raise ValueError("Invalid signature file %s" % args.signature)
+        with open(args.signature, "rb") as f:
+            sig = f.read()
+        if len(sig) != DBC_SIG_SIZE:
+            raise ValueError(
+                "Invalid signature length %d (expected %d)" % (len(sig), DBC_SIG_SIZE)
+            )
+    if args.uid:
+        if not os.path.exists(args.uid):
+            raise ValueError("Invalid uid file %s" % args.uid)
+        with open(args.uid, "rb") as f:
+            uid = f.read()
+        if len(uid) != DBC_UID_SIZE:
+            raise ValueError(
+                "Invalid UID length %d (expected %d)" % (len(uid), DBC_UID_SIZE)
+            )
+    if args.data:
+        try:
+            data = int(args.data, 10)
+        except ValueError:
+            data = int(args.data, 16)
+
+    with open(args.device) as d:
+        if args.command == "get-nonce":
+            try:
+                nonce = get_nonce(d, sig)
+                print("Nonce: %s" % _pretty_buffer(bytes(nonce)))
+            except OSError as e:
+                pretty_error(e.errno)
+        elif args.command == "set-uid":
+            try:
+                result = set_uid(d, uid, sig)
+                if result:
+                    print("Set UID")
+            except OSError as e:
+                pretty_error(e.errno)
+        elif args.command == "get-param":
+            if not args.message or args.message.startswith("set"):
+                raise ValueError("Invalid message %s" % args.message)
+            try:
+                param, signature = process_param(d, messages[args.message], sig)
+                print(
+                    "Parameter: {par}, response signature {sig}".format(
+                        par=param,
+                        sig=_pretty_buffer(bytes(signature)),
+                    )
+                )
+            except OSError as e:
+                pretty_error(e.errno)
+        elif args.command == "set-param":
+            if not args.message or args.message.startswith("get"):
+                raise ValueError("Invalid message %s" % args.message)
+            try:
+                param, signature = process_param(d, messages[args.message], sig, data)
+                print(
+                    "Parameter: {par}, response signature {sig}".format(
+                        par=param,
+                        sig=_pretty_buffer(bytes(signature)),
+                    )
+                )
+            except OSError as e:
+                pretty_error(e.errno)