[v11,03/15] FWU: Add FWU metadata access driver for GPT partitioned block devices

In the FWU Multi Bank Update feature, the information about the
updatable images is stored as part of the metadata, on a separate
partition. Add a driver for reading from and writing to the metadata
when the updatable images and the metadata are stored on a block
device which is formatted with GPT based partition scheme.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
---
Changes since V10:
* Use array for storing the metadata partition numbers as suggested by
  Ilias
* Skip a couple of goto's in gpt_check_mdata_validity() as suggested
  by Ilias
* Have the FWU_MDATA_GPT_BLK config symbol depend on FWU_MDATA and BLK
* Remove the comment in fwu_gpt_mdata_check() as it is already
  mentioned in the corresponding API comment

 drivers/fwu-mdata/Kconfig   |  16 ++
 drivers/fwu-mdata/Makefile  |   8 +
 drivers/fwu-mdata/gpt_blk.c | 356 ++++++++++++++++++++++++++++++++++++
 include/fwu.h               |   4 +
 4 files changed, 384 insertions(+)
 create mode 100644 drivers/fwu-mdata/Kconfig
 create mode 100644 drivers/fwu-mdata/Makefile
 create mode 100644 drivers/fwu-mdata/gpt_blk.c

Hi Sughosh,

My R-b tag still applies, with the 2 below comments addressed or not.

Br,
etienne

On Wed, 28 Sept 2022 at 11:30, Sughosh Ganu <sughosh.ganu@linaro.org> wrote:
>
> In the FWU Multi Bank Update feature, the information about the
> updatable images is stored as part of the metadata, on a separate
> partition. Add a driver for reading from and writing to the metadata
> when the updatable images and the metadata are stored on a block
> device which is formatted with GPT based partition scheme.
>
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
> Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
> ---
> Changes since V10:
> * Use array for storing the metadata partition numbers as suggested by
>   Ilias
> * Skip a couple of goto's in gpt_check_mdata_validity() as suggested
>   by Ilias
> * Have the FWU_MDATA_GPT_BLK config symbol depend on FWU_MDATA and BLK
> * Remove the comment in fwu_gpt_mdata_check() as it is already
>   mentioned in the corresponding API comment
>
>  drivers/fwu-mdata/Kconfig   |  16 ++
>  drivers/fwu-mdata/Makefile  |   8 +
>  drivers/fwu-mdata/gpt_blk.c | 356 ++++++++++++++++++++++++++++++++++++
>  include/fwu.h               |   4 +
>  4 files changed, 384 insertions(+)
>  create mode 100644 drivers/fwu-mdata/Kconfig
>  create mode 100644 drivers/fwu-mdata/Makefile
>  create mode 100644 drivers/fwu-mdata/gpt_blk.c
>
> diff --git a/drivers/fwu-mdata/Kconfig b/drivers/fwu-mdata/Kconfig
> new file mode 100644
> index 0000000000..36c4479a59
> --- /dev/null
> +++ b/drivers/fwu-mdata/Kconfig
> @@ -0,0 +1,16 @@
> +config FWU_MDATA
> +       bool "Driver support for accessing FWU Metadata"
> +       depends on DM
> +       help
> +         Enable support for accessing FWU Metadata partitions. The
> +         FWU Metadata partitions reside on the same storage device
> +         which contains the other FWU updatable firmware images.
> +
> +config FWU_MDATA_GPT_BLK
> +       bool "FWU Metadata access for GPT partitioned Block devices"
> +       select PARTITION_TYPE_GUID
> +       select PARTITION_UUIDS
> +       depends on FWU_MDATA && BLK && EFI_PARTITION
> +       help
> +         Enable support for accessing FWU Metadata on GPT partitioned
> +         block devices.
> diff --git a/drivers/fwu-mdata/Makefile b/drivers/fwu-mdata/Makefile
> new file mode 100644
> index 0000000000..3fee64c10c
> --- /dev/null
> +++ b/drivers/fwu-mdata/Makefile
> @@ -0,0 +1,8 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +#
> +# Copyright (c) 2022, Linaro Limited
> +#
> +
> +
> +obj-$(CONFIG_FWU_MDATA) += fwu-mdata-uclass.o
> +obj-$(CONFIG_FWU_MDATA_GPT_BLK) += gpt_blk.o
> diff --git a/drivers/fwu-mdata/gpt_blk.c b/drivers/fwu-mdata/gpt_blk.c
> new file mode 100644
> index 0000000000..d20bb19d52
> --- /dev/null
> +++ b/drivers/fwu-mdata/gpt_blk.c
> @@ -0,0 +1,356 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2022, Linaro Limited
> + */
> +
> +#define LOG_CATEGORY UCLASS_FWU_MDATA
> +
> +#include <blk.h>
> +#include <dm.h>
> +#include <efi_loader.h>
> +#include <fwu.h>
> +#include <fwu_mdata.h>
> +#include <log.h>
> +#include <memalign.h>
> +#include <part.h>
> +#include <part_efi.h>
> +
> +#include <dm/device-internal.h>
> +#include <linux/errno.h>
> +#include <linux/types.h>
> +
> +#define PRIMARY_PART           BIT(0)
> +#define SECONDARY_PART         BIT(1)
> +#define BOTH_PARTS             (PRIMARY_PART | SECONDARY_PART)
> +
> +#define MDATA_READ             BIT(0)
> +#define MDATA_WRITE            BIT(1)
> +
> +static int gpt_get_mdata_partitions(struct blk_desc *desc,
> +                                   uint *mdata_parts)

Maybe nitpicking but I think this should better explicit declare a 2
cell array argument:
static int gpt_get_mdata_partitions(struct blk_desc *desc, uint mdata_parts[2])

> +{
> +       int i, ret;
> +       u32 nparts;
> +       efi_guid_t part_type_guid;
> +       struct disk_partition info;
> +       const efi_guid_t fwu_mdata_guid = FWU_MDATA_GUID;
> +
> +       nparts = 0;
> +       for (i = 1; i < MAX_SEARCH_PARTITIONS; i++) {
> +               if (part_get_info(desc, i, &info))
> +                       continue;
> +               uuid_str_to_bin(info.type_guid, part_type_guid.b,
> +                               UUID_STR_FORMAT_GUID);
> +
> +               if (nparts < 2 && !guidcmp(&fwu_mdata_guid, &part_type_guid)) {
> +                       mdata_parts[nparts] = i;
> +                       ++nparts;
> +               }
> +       }
> +
> +       if (nparts != 2) {
> +               log_debug("Expect two copies of the FWU metadata instead of %d\n",
> +                         nparts);
> +               ret = -EINVAL;
> +       } else {
> +               ret = 0;
> +       }
> +
> +       return ret;
> +}
> +
> +static int gpt_get_mdata_disk_part(struct blk_desc *desc,
> +                                  struct disk_partition *info,
> +                                  u32 part_num)
> +{
> +       int ret;
> +       char *mdata_guid_str = "8a7a84a0-8387-40f6-ab41-a8b9a5a60d23";
> +
> +       ret = part_get_info(desc, part_num, info);
> +       if (ret < 0) {
> +               log_debug("Unable to get the partition info for the FWU metadata part %d\n",
> +                         part_num);
> +               return -ENOENT;
> +       }
> +
> +       /* Check that it is indeed the FWU metadata partition */
> +       if (!strncmp(info->type_guid, mdata_guid_str, UUID_STR_LEN)) {
> +               /* Found the FWU metadata partition */
> +               return 0;
> +       }
> +
> +       return -ENOENT;
> +}
> +
> +static int gpt_read_write_mdata(struct blk_desc *desc,
> +                               struct fwu_mdata *mdata,
> +                               u8 access, u32 part_num)
> +{
> +       int ret;
> +       u32 len, blk_start, blkcnt;
> +       struct disk_partition info;
> +
> +       ALLOC_CACHE_ALIGN_BUFFER_PAD(struct fwu_mdata, mdata_aligned, 1,
> +                                    desc->blksz);
> +
> +       ret = gpt_get_mdata_disk_part(desc, &info, part_num);
> +       if (ret < 0) {
> +               printf("Unable to get the FWU metadata partition\n");
> +               return -ENOENT;
> +       }
> +
> +       len = sizeof(*mdata);
> +       blkcnt = BLOCK_CNT(len, desc);
> +       if (blkcnt > info.size) {
> +               log_debug("Block count exceeds FWU metadata partition size\n");
> +               return -ERANGE;
> +       }
> +
> +       blk_start = info.start;
> +       if (access == MDATA_READ) {
> +               if (blk_dread(desc, blk_start, blkcnt, mdata_aligned) != blkcnt) {
> +                       log_debug("Error reading FWU metadata from the device\n");
> +                       return -EIO;
> +               }
> +               memcpy(mdata, mdata_aligned, sizeof(struct fwu_mdata));
> +       } else {
> +               if (blk_dwrite(desc, blk_start, blkcnt, mdata) != blkcnt) {
> +                       log_debug("Error writing FWU metadata to the device\n");
> +                       return -EIO;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> +static int gpt_read_mdata(struct blk_desc *desc,
> +                         struct fwu_mdata *mdata, u32 part_num)
> +{
> +       return gpt_read_write_mdata(desc, mdata, MDATA_READ, part_num);
> +}
> +
> +static int gpt_write_mdata_partition(struct blk_desc *desc,
> +                                    struct fwu_mdata *mdata,
> +                                    u32 part_num)
> +{
> +       return gpt_read_write_mdata(desc, mdata, MDATA_WRITE, part_num);
> +}
> +
> +static int fwu_gpt_update_mdata(struct udevice *dev, struct fwu_mdata *mdata)
> +{
> +       int ret;
> +       struct blk_desc *desc;
> +       uint mdata_parts[2];
> +       struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
> +
> +       desc = dev_get_uclass_plat(priv->blk_dev);
> +
> +       ret = gpt_get_mdata_partitions(desc, mdata_parts);
> +       if (ret < 0) {
> +               log_debug("Error getting the FWU metadata partitions\n");
> +               return -ENOENT;
> +       }
> +
> +       /* First write the primary partition */
> +       ret = gpt_write_mdata_partition(desc, mdata, mdata_parts[0]);
> +       if (ret < 0) {
> +               log_debug("Updating primary FWU metadata partition failed\n");
> +               return ret;
> +       }
> +
> +       /* And now the replica */
> +       ret = gpt_write_mdata_partition(desc, mdata, mdata_parts[1]);
> +       if (ret < 0) {
> +               log_debug("Updating secondary FWU metadata partition failed\n");
> +               return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +static int gpt_get_mdata(struct blk_desc *desc, struct fwu_mdata *mdata)
> +{
> +       int ret;
> +       uint mdata_parts[2];
> +
> +       ret = gpt_get_mdata_partitions(desc, mdata_parts);
> +
> +       if (ret < 0) {
> +               log_debug("Error getting the FWU metadata partitions\n");
> +               return -ENOENT;
> +       }
> +
> +       ret = gpt_read_mdata(desc, mdata, mdata_parts[0]);
> +       if (ret < 0) {
> +               log_debug("Failed to read the FWU metadata from the device\n");
> +               return -EIO;
> +       }
> +
> +       ret = fwu_verify_mdata(mdata, 1);
> +       if (!ret)
> +               return 0;
> +
> +       /*
> +        * Verification of the primary FWU metadata copy failed.
> +        * Try to read the replica.
> +        */
> +       memset(mdata, '\0', sizeof(struct fwu_mdata));
> +       ret = gpt_read_mdata(desc, mdata, mdata_parts[1]);
> +       if (ret < 0) {
> +               log_debug("Failed to read the FWU metadata from the device\n");
> +               return -EIO;
> +       }
> +
> +       ret = fwu_verify_mdata(mdata, 0);
> +       if (!ret)
> +               return 0;
> +
> +       /* Both the FWU metadata copies are corrupted. */
> +       return -EIO;
> +}
> +
> +static int gpt_check_mdata_validity(struct udevice *dev)
> +{
> +       int ret;
> +       struct blk_desc *desc;
> +       struct fwu_mdata pri_mdata;
> +       struct fwu_mdata secondary_mdata;
> +       uint mdata_parts[2];
> +       uint valid_partitions, invalid_partitions;
> +       struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
> +
> +       desc = dev_get_uclass_plat(priv->blk_dev);
> +
> +       /*
> +        * Two FWU metadata partitions are expected.
> +        * If we don't have two, user needs to create
> +        * them first
> +        */
> +       valid_partitions = 0;
> +       ret = gpt_get_mdata_partitions(desc, mdata_parts);
> +       if (ret < 0) {
> +               log_debug("Error getting the FWU metadata partitions\n");
> +               return -ENOENT;
> +       }
> +
> +       ret = gpt_read_mdata(desc, &pri_mdata, mdata_parts[0]);
> +       if (!ret) {
> +               ret = fwu_verify_mdata(&pri_mdata, 1);
> +               if (!ret)
> +                       valid_partitions |= PRIMARY_PART;
> +       }
> +
> +       /* Now check the secondary partition */
> +       ret = gpt_read_mdata(desc, &secondary_mdata, mdata_parts[1]);
> +       if (!ret) {
> +               ret = fwu_verify_mdata(&secondary_mdata, 0);
> +               if (!ret)
> +                       valid_partitions |= SECONDARY_PART;
> +       }
> +
> +       if (valid_partitions == (PRIMARY_PART | SECONDARY_PART)) {
> +               ret = -1;
> +               /*
> +                * Before returning, check that both the
> +                * FWU metadata copies are the same. If not,
> +                * the FWU metadata copies need to be
> +                * re-populated.
> +                */
> +               if (!memcmp(&pri_mdata, &secondary_mdata,
> +                           sizeof(struct fwu_mdata))) {
> +                       ret = 0;
> +               } else {
> +                       log_debug("Both FWU metadata copies are valid but do not match. Please check!\n");
> +               }
> +               goto out;
> +       }
> +
> +       ret = -1;
> +       if (!(valid_partitions & BOTH_PARTS))
> +               goto out;

The 3 above preload of @ret are a bit misplaced (yet no functional
issue) i think.
Better a classic way:

       if (valid_partitions == (PRIMARY_PART | SECONDARY_PART)) {
-               ret = -1;
                (...)
                if (!memcmp(&pri_mdata, &secondary_mdata,
                            sizeof(struct fwu_mdata))) {
                        ret = 0;
                } else {
                        log_debug("Both FWU metadata copies are valid
but do not match. Please check!\n");
+                       ret = -1;
                }
                goto out;
        }

-       ret = -1;
        if (!(valid_partitions & BOTH_PARTS)) {
+              ret = -1;
               goto out;
       }




> +
> +       invalid_partitions = valid_partitions ^ BOTH_PARTS;
> +       ret = gpt_write_mdata_partition(desc,
> +                                       (invalid_partitions == PRIMARY_PART) ?
> +                                       &secondary_mdata : &pri_mdata,
> +                                       (invalid_partitions == PRIMARY_PART) ?
> +                                       mdata_parts[0] : mdata_parts[1]);
> +
> +       if (ret < 0)
> +               log_debug("Restoring %s FWU metadata partition failed\n",
> +                         (invalid_partitions == PRIMARY_PART) ?
> +                         "primary" : "secondary");
> +
> +out:
> +       return ret;
> +}
> +
> +static int fwu_gpt_mdata_check(struct udevice *dev)
> +{
> +       return gpt_check_mdata_validity(dev);
> +}
> +
> +static int fwu_gpt_get_mdata(struct udevice *dev, struct fwu_mdata *mdata)
> +{
> +       struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
> +
> +       return gpt_get_mdata(dev_get_uclass_plat(priv->blk_dev), mdata);
> +}
> +
> +static int fwu_get_mdata_device(struct udevice *dev, struct udevice **mdata_dev)
> +{
> +       u32 phandle;
> +       int ret, size;
> +       struct udevice *parent;
> +       const fdt32_t *phandle_p = NULL;
> +
> +       phandle_p = dev_read_prop(dev, "fwu-mdata-store", &size);
> +       if (!phandle_p) {
> +               log_debug("fwu-mdata-store property not found\n");
> +               return -ENOENT;
> +       }
> +
> +       phandle = fdt32_to_cpu(*phandle_p);
> +
> +       ret = device_get_global_by_ofnode(ofnode_get_by_phandle(phandle),
> +                                         &parent);
> +       if (ret)
> +               return ret;
> +
> +       return blk_get_from_parent(parent, mdata_dev);
> +}
> +
> +static int fwu_mdata_gpt_blk_probe(struct udevice *dev)
> +{
> +       int ret;
> +       struct udevice *mdata_dev = NULL;
> +       struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
> +
> +       ret = fwu_get_mdata_device(dev, &mdata_dev);
> +       if (ret)
> +               return ret;
> +
> +       priv->blk_dev = mdata_dev;
> +
> +       return 0;
> +}
> +
> +static const struct fwu_mdata_ops fwu_gpt_blk_ops = {
> +       .check_mdata = fwu_gpt_mdata_check,
> +       .get_mdata = fwu_gpt_get_mdata,
> +       .update_mdata = fwu_gpt_update_mdata,
> +};
> +
> +static const struct udevice_id fwu_mdata_ids[] = {
> +       { .compatible = "u-boot,fwu-mdata-gpt" },
> +       { }
> +};
> +
> +U_BOOT_DRIVER(fwu_mdata_gpt_blk) = {
> +       .name           = "fwu-mdata-gpt-blk",
> +       .id             = UCLASS_FWU_MDATA,
> +       .of_match       = fwu_mdata_ids,
> +       .ops            = &fwu_gpt_blk_ops,
> +       .probe          = fwu_mdata_gpt_blk_probe,
> +       .priv_auto      = sizeof(struct fwu_mdata_gpt_blk_priv),
> +};
> diff --git a/include/fwu.h b/include/fwu.h
> index a4d2d35d9a..167f91388e 100644
> --- a/include/fwu.h
> +++ b/include/fwu.h
> @@ -14,6 +14,10 @@
>  struct fwu_mdata;
>  struct udevice;
>
> +struct fwu_mdata_gpt_blk_priv {
> +       struct udevice *blk_dev;
> +};
> +
>  /**
>   * @mdata_check: check the validity of the FWU metadata partitions
>   * @get_mdata() - Get a FWU metadata copy
> --
> 2.34.1
>