Re: [PATCH 1/2] firmware: Google VPD: import lib_vpd source files

Greg Kroah-Hartman
2017-04-11T14:10:25Z

On Tue, Apr 11, 2017 at 11:14:30AM +0200, Thierry Escande wrote:
> From: Wei-Ning Huang <wnhuang@google.com>
>
> This patch imports lib_vpd.h and vpd_decode.c from the Chromium Vital
> Product Data project.
>
> This library is used to parse VPD sections obtained from coreboot table
> entries describing Chromebook devices product data. Only the sections of
> type VPD_TYPE_STRING are decoded.
>
> The VPD string sections in the coreboot tables contain the type (1 byte
> set to 0x01 for strings), the key length, the key ascii array, the value
> length, and the value ascii array. The key and value arrays are not null
> terminated.
>
> Signed-off-by: Wei-Ning Huang <wnhuang@google.com>
> Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
> ---
> drivers/firmware/google/vpd_decode.c | 99 ++++++++++++++++++++++++++++++++++++
> drivers/firmware/google/vpd_decode.h | 59 +++++++++++++++++++++
> 2 files changed, 158 insertions(+)
> create mode 100644 drivers/firmware/google/vpd_decode.c
> create mode 100644 drivers/firmware/google/vpd_decode.h
>
> diff --git a/drivers/firmware/google/vpd_decode.c b/drivers/firmware/google/vpd_decode.c
> new file mode 100644
> index 0000000..75e4027
> --- /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 decode_len(const int32_t max_len, const uint8_t *in,
> + int32_t *length, int32_t *decoded_len)
> +{
> + uint8_t 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 decode_vpd_string(const int32_t max_len, const uint8_t *input_buf,
> + int32_t *consumed, vpd_decode_callback callback,
> + void *callback_arg)
> +{
> + int type;
> + int res;
> + int32_t key_len, value_len;
> + int32_t decoded_len;
> + const uint8_t *key, *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 = 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 = 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;
> +}
> +EXPORT_SYMBOL(decode_vpd_string);

Normally put the prefix for the driver you are exporting from:
vpd_string_decode()?

And EXPORT_SYMBOL_GPL() perhaps?

thanks,

greg k-h