v4.19.13 snapshot.
diff --git a/drivers/firmware/google/vpd_decode.c b/drivers/firmware/google/vpd_decode.c
new file mode 100644
index 0000000..943acaa
--- /dev/null
+++ b/drivers/firmware/google/vpd_decode.c
@@ -0,0 +1,99 @@
+/*
+ * vpd_decode.c
+ *
+ * Google VPD decoding routines.
+ *
+ * Copyright 2017 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License v2.0 as published by
+ * the Free Software Foundation.
+ *
+ * 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 the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/export.h>
+
+#include "vpd_decode.h"
+
+static int vpd_decode_len(const s32 max_len, const u8 *in,
+ s32 *length, s32 *decoded_len)
+{
+ u8 more;
+ int i = 0;
+
+ if (!length || !decoded_len)
+ return VPD_FAIL;
+
+ *length = 0;
+ do {
+ if (i >= max_len)
+ return VPD_FAIL;
+
+ more = in[i] & 0x80;
+ *length <<= 7;
+ *length |= in[i] & 0x7f;
+ ++i;
+ } while (more);
+
+ *decoded_len = i;
+
+ return VPD_OK;
+}
+
+int vpd_decode_string(const s32 max_len, const u8 *input_buf, s32 *consumed,
+ vpd_decode_callback callback, void *callback_arg)
+{
+ int type;
+ int res;
+ s32 key_len;
+ s32 value_len;
+ s32 decoded_len;
+ const u8 *key;
+ const u8 *value;
+
+ /* type */
+ if (*consumed >= max_len)
+ return VPD_FAIL;
+
+ type = input_buf[*consumed];
+
+ switch (type) {
+ case VPD_TYPE_INFO:
+ case VPD_TYPE_STRING:
+ (*consumed)++;
+
+ /* key */
+ res = vpd_decode_len(max_len - *consumed, &input_buf[*consumed],
+ &key_len, &decoded_len);
+ if (res != VPD_OK || *consumed + decoded_len >= max_len)
+ return VPD_FAIL;
+
+ *consumed += decoded_len;
+ key = &input_buf[*consumed];
+ *consumed += key_len;
+
+ /* value */
+ res = vpd_decode_len(max_len - *consumed, &input_buf[*consumed],
+ &value_len, &decoded_len);
+ if (res != VPD_OK || *consumed + decoded_len > max_len)
+ return VPD_FAIL;
+
+ *consumed += decoded_len;
+ value = &input_buf[*consumed];
+ *consumed += value_len;
+
+ if (type == VPD_TYPE_STRING)
+ return callback(key, key_len, value, value_len,
+ callback_arg);
+ break;
+
+ default:
+ return VPD_FAIL;
+ }
+
+ return VPD_OK;
+}