Re: [PATCH v7 02/13] FWU: Add FWU metadata structure and driver for accessing metadata

[Ilias Apalodimas <ilias.apalodimas@linaro.org>]

Hi Sughosh,

> + */
> +
> +#define LOG_CATEGORY UCLASS_FWU_MDATA

[...]

> +
> +/**
> + * fwu_verify_mdata() - Verify the FWU metadata
> + * @mdata: FWU metadata structure
> + * @pri_part: FWU metadata partition is primary or secondary
> + *
> + * Verify the FWU metadata by computing the CRC32 for the metadata
> + * structure and comparing it against the CRC32 value stored as part
> + * of the structure.

> +/**
> + * fwu_update_active_index() - Update active_index from the FWU metadata
> + * @active_idx: active_index value to be updated

> +int fwu_update_active_index(u32 active_idx)
> +{
> +       int ret;
> +       struct fwu_mdata *mdata = NULL;
> +
> +       if (active_idx > CONFIG_FWU_NUM_BANKS - 1) {
> +               log_err("Active index value to be updated is incorrect\n");

Nit but "Invalid active index value" is makes more sense

> +               return -1;
> +       }
> +

[...]

> +}
> +
> +/**
> + * fwu_get_image_alt_num() - Get the dfu alt number to be used for capsule update
> + * @image_type_id: pointer to the image guid as passed in the capsule
> + * @update_bank: Bank to which the update is to be made
> + * @alt_num: The alt_num for the image
> + *
> + * Based on the guid value passed in the capsule, along with the bank to which the
> + * image needs to be updated, get the dfu alt number which will be used for the
> + * capsule update
> + *
> + * Return: 0 if OK, -ve on error
> + *
> + */
> +int fwu_get_image_alt_num(efi_guid_t *image_type_id, u32 update_bank,
> +                         int *alt_num)
> +{
> +       int ret, i;
> +       efi_guid_t *image_guid;
> +       struct udevice *dev = NULL;
> +       struct fwu_mdata *mdata = NULL;
> +       struct fwu_image_entry *img_entry;
> +       const struct fwu_mdata_ops *ops = NULL;
> +       struct fwu_image_bank_info *img_bank_info;
> +
> +       ret = fwu_get_dev_ops(&dev, &ops);
> +       if (ret)
> +               return ret;
> +
> +       ret = fwu_get_mdata(&mdata);
> +       if (ret) {
> +               log_err("Unable to get valid FWU metadata\n");
> +               goto out;
> +       }
> +
> +       /*
> +        * The FWU metadata has been read. Now get the image_uuid for the
> +        * image with the update_bank.
> +        */
> +       for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; i++) {
> +               if (!guidcmp(image_type_id,
> +                            &mdata->img_entry[i].image_type_uuid)) {
> +                       img_entry = &mdata->img_entry[i];
> +                       img_bank_info = &img_entry->img_bank_info[update_bank];
> +                       image_guid = &img_bank_info->image_uuid;
> +                       ret = fwu_plat_get_alt_num(dev, image_guid, alt_num);
> +                       break;
> +               }
> +       }
> +

I think if you set ret = -EINVAL on top of the for loop you can mostly
get rid of the code below.
ret = -EINVAL
for () {
.....
    ret = fwu_plat_get_alt_num(dev, image_guid, alt_num);
    if (ret)
        log_err("alt_num not found for partition with GUID %pUs\n", image_guid);
    goto out; //on success instead of break
}
log_err("Partition with the image type %pUs not found\n", image_type_id);

out:
free(mdata);

return ret;

Isn't that more readable?

> +       if (i == CONFIG_FWU_NUM_IMAGES_PER_BANK) {
> +               log_err("Partition with the image type %pUs not found\n",
> +                       image_type_id);
> +               ret = -EINVAL;
> +               goto out;
> +       }
> +
> +       if (!ret) {
> +               log_debug("alt_num %d for partition %pUs\n",
> +                         *alt_num, image_guid);
> +       } else {
> +               log_err("alt_num not found for partition with GUID %pUs\n",
> +                       image_guid);
> +               ret = -EINVAL;
> +       }
> +
> +out:
> +       free(mdata);
> +
> +       return ret;
> +}
> +
> +/**

[...]

               u32 bank, u8 action)
> +{
> +       int ret, i;
> +       u32 nimages;

Get rid of nimages when they are only used as
CONFIG_FWU_NUM_IMAGES_PER_BANK (there's more than one)

[...]

> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
> index a432e43871..598a8c10a0 100644
> @@ -0,0 +1,67 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Copyright (c) 2022, Linaro Limited
> + */
> +
> +#if !defined _FWU_MDATA_H_
> +#define _FWU_MDATA_H_
> +
> +#include <efi.h>
> +
> +/**
> + * struct fwu_image_bank_info - firmware image information
> + * @image_uuid: Guid value of the image in this bank
> + * @accepted: Acceptance status of the image
> + * @reserved: Reserved
> + *
> + * The structure contains image specific fields which are
> + * used to identify the image and to specify the image's
> + * acceptance status
> + */
> +struct fwu_image_bank_info {
> +       efi_guid_t  image_uuid;
> +       uint32_t accepted;
> +       uint32_t reserved;
> +} __attribute__((__packed__));

The spec doesn't require those to be packed.  If there's a reason we
should have it in comments, otherwise just drop the packed attribute

> +
> +/**
> + * struct fwu_image_entry - information for a particular type of image
> + * @image_type_uuid: Guid value for identifying the image type
> + * @location_uuid: Guid of the storage volume where the image is located
> + * @img_bank_info: Array containing properties of images
> + *
> + * This structure contains information on various types of updatable
> + * firmware images. Each image type then contains an array of image
> + * information per bank.
> + */
> +struct fwu_image_entry {
> +       efi_guid_t image_type_uuid;
> +       efi_guid_t location_uuid;
> +       struct fwu_image_bank_info img_bank_info[CONFIG_FWU_NUM_BANKS];
> +} __attribute__((__packed__));
> +
> +/**
> + * struct fwu_mdata - FWU metadata structure for multi-bank updates
> + * @crc32: crc32 value for the FWU metadata
> + * @version: FWU metadata version
> + * @active_index: Index of the bank currently used for booting images
> + * @previous_active_inde: Index of the bank used before the current bank
> + *                        being used for booting
> + * @img_entry: Array of information on various firmware images that can
> + *             be updated
> + *
> + * This structure is used to store all the needed information for performing
> + * multi bank updates on the platform. This contains info on the bank being
> + * used to boot along with the information needed for identification of
> + * individual images
> + */
> +struct fwu_mdata {
> +       uint32_t crc32;
> +       uint32_t version;
> +       uint32_t active_index;
> +       uint32_t previous_active_index;
> +
> +       struct fwu_image_entry img_entry[CONFIG_FWU_NUM_IMAGES_PER_BANK];
> +} __attribute__((__packed__));
> +
> +#endif /* _FWU_MDATA_H_ */
> --
> 2.34.1
>

Thanks!
/Ilias