Re: [PATCH v5 03/23] FWU: Add FWU metadata access driver for GPT partitioned block devices

Etienne Carriere
2022-06-21T10:56:19Z

Hello Sughosh,

On Thu, 9 Jun 2022 at 14:30, 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 formated with GPT based partition scheme.
>
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> ---
> drivers/fwu-mdata/Kconfig | 9 +
> drivers/fwu-mdata/Makefile | 1 +
> drivers/fwu-mdata/fwu_mdata_gpt_blk.c | 404 ++++++++++++++++++++++++++
> include/fwu.h | 2 +
> 4 files changed, 416 insertions(+)
> create mode 100644 drivers/fwu-mdata/fwu_mdata_gpt_blk.c
>
> diff --git a/drivers/fwu-mdata/Kconfig b/drivers/fwu-mdata/Kconfig
> index d6a21c8e19..d5edef19d6 100644
> --- a/drivers/fwu-mdata/Kconfig
> +++ b/drivers/fwu-mdata/Kconfig
> @@ -5,3 +5,12 @@ config DM_FWU_MDATA
> 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 DM && HAVE_BLOCK_DEVICE && 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
> index 7fec7171f4..12a5b4fe04 100644
> --- a/drivers/fwu-mdata/Makefile
> +++ b/drivers/fwu-mdata/Makefile
> @@ -4,3 +4,4 @@
> #
>
> obj-$(CONFIG_DM_FWU_MDATA) += fwu-mdata-uclass.o
> +obj-$(CONFIG_FWU_MDATA_GPT_BLK) += fwu_mdata_gpt_blk.o
> diff --git a/drivers/fwu-mdata/fwu_mdata_gpt_blk.c b/drivers/fwu-mdata/fwu_mdata_gpt_blk.c
> new file mode 100644
> index 0000000000..329bd3779b
> --- /dev/null
> +++ b/drivers/fwu-mdata/fwu_mdata_gpt_blk.c
> @@ -0,0 +1,404 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2022, Linaro Limited
> + */
> +
> +#include <blk.h>
> +#include <dm.h>
> +#include <efi_loader.h>
> +#include <fwu.h>
> +#include <fwu_mdata.h>
> +#include <log.h>
> +#include <malloc.h>
> +#include <memalign.h>
> +#include <part.h>
> +#include <part_efi.h>
> +
> +#include <dm/device-internal.h>
> +#include <linux/errno.h>
> +#include <linux/types.h>
> +#include <u-boot/crc.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,
> + u16 *primary_mpart,
> + u16 *secondary_mpart)
> +{
> + int i, ret;
> + u32 mdata_parts;
> + efi_guid_t part_type_guid;
> + struct disk_partition info;
> + const efi_guid_t fwu_mdata_guid = FWU_MDATA_GUID;
> +
> + mdata_parts = 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 (!guidcmp(&fwu_mdata_guid, &part_type_guid)) {
> + ++mdata_parts;
> + if (!*primary_mpart)
> + *primary_mpart = i;
> + else
> + *secondary_mpart = i;
> + }
> + }
> +
> + if (mdata_parts != 2) {
> + log_err("Expect two copies of the FWU metadata instead of %d\n",
> + mdata_parts);
> + 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_err("Unable to get the partition info for the FWU metadata part %d",
> + part_num);
> + return -1;
> + }
> +
> + /* 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 -1;
> +}
> +
> +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 -ENODEV;
> + }
> +
> + len = sizeof(*mdata);
> + blkcnt = BLOCK_CNT(len, desc);
> + if (blkcnt > info.size) {
> + log_err("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_err("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_err("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;
> + u16 primary_mpart = 0, secondary_mpart = 0;
> +
> + desc = dev_get_uclass_plat(dev_get_priv(dev));
> + if (!desc) {
> + log_err("Block device not found\n");
> + return -ENODEV;
> + }
> +
> + ret = gpt_get_mdata_partitions(desc, &primary_mpart,
> + &secondary_mpart);
> +
> + if (ret < 0) {
> + log_err("Error getting the FWU metadata partitions\n");
> + return -ENODEV;
> + }
> +
> + /* First write the primary partition*/
> + ret = gpt_write_mdata_partition(desc, mdata, primary_mpart);
> + if (ret < 0) {
> + log_err("Updating primary FWU metadata partition failed\n");
> + return ret;
> + }
> +
> + /* And now the replica */
> + ret = gpt_write_mdata_partition(desc, mdata, secondary_mpart);
> + if (ret < 0) {
> + log_err("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;
> + u16 primary_mpart = 0, secondary_mpart = 0;
> +
> + ret = gpt_get_mdata_partitions(desc, &primary_mpart,
> + &secondary_mpart);
> +
> + if (ret < 0) {
> + log_err("Error getting the FWU metadata partitions\n");
> + return -ENODEV;
> + }
> +
> + *mdata = malloc(sizeof(struct fwu_mdata));
> + if (!*mdata) {
> + log_err("Unable to allocate memory for reading FWU metadata\n");
> + return -ENOMEM;
> + }
> +
> + ret = gpt_read_mdata(desc, *mdata, primary_mpart);
> + if (ret < 0) {
> + log_err("Failed to read the FWU metadata from the device\n");
> + return -EIO;
> + }
> +
> + ret = fwu_verify_mdata(*mdata, 1);
> + if (!ret)

Upon success, I think this function should also either ensure
secondary_part contains a valid copy of primary part,
Maybe this function should call gpt_check_mdata_validity() and then
read mdata content.

> + 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, secondary_mpart);
> + if (ret < 0) {
> + log_err("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 -1;
> +}
> +
> +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;
> + u16 primary_mpart = 0, secondary_mpart = 0;
> + u16 valid_partitions, invalid_partitions;
> +
> + desc = dev_get_uclass_plat(dev_get_priv(dev));
> + if (!desc) {
> + log_err("Block device not found\n");
> + return -ENODEV;
> + }
> +
> + /*
> + * 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, &primary_mpart,
> + &secondary_mpart);
> +
> + if (ret < 0) {
> + log_err("Error getting the FWU metadata partitions\n");
> + return -ENODEV;
> + }
> +
> + ret = gpt_read_mdata(desc, &pri_mdata, primary_mpart);
> + if (ret < 0) {
> + log_err("Failed to read the FWU metadata from the device\n");
> + goto secondary_read;
> + }
> +
> + ret = fwu_verify_mdata(&pri_mdata, 1);
> + if (!ret)
> + valid_partitions |= PRIMARY_PART;
> +
> +secondary_read:
> + /* Now check the secondary partition */
> + ret = gpt_read_mdata(desc, &secondary_mdata, secondary_mpart);
> + if (ret < 0) {
> + log_err("Failed to read the FWU metadata from the device\n");
> + goto mdata_restore;
> + }
> +
> + ret = fwu_verify_mdata(&secondary_mdata, 0);
> + if (!ret)
> + valid_partitions |= SECONDARY_PART;
> +
> +mdata_restore:
> + 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_err("Both FWU metadata copies are valid but do not match. Please check!\n");

I think this function should select one of the part and copies to the
other, e.g. assume primary is fine, copy primary to secondary and
return upon success.

> + }
> + goto out;
> + }
> +
> + ret = -1;
> + if (!(valid_partitions & BOTH_PARTS))
> + 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) ?
> + primary_mpart : secondary_mpart);
> +
> + if (ret < 0)
> + log_err("Restoring %s FWU metadata partition failed\n",
> + (invalid_partitions == PRIMARY_PART) ?
> + "primary" : "secondary");
> +
> +out:
> + return ret;
> +}
> +
> +int fwu_gpt_mdata_check(struct udevice *dev)

Function should be static.

> +{
> + /*
> + * Check if both the copies of the FWU metadata are
> + * valid. If one has gone bad, restore it from the
> + * other good copy.
> + */
> + return gpt_check_mdata_validity(dev);
> +}
> +
> +int fwu_gpt_get_mdata(struct udevice *dev, struct fwu_mdata **mdata)

Function should be static.

> +{
> + struct blk_desc *desc;
> +
> + desc = dev_get_uclass_plat(dev_get_priv(dev));
> + if (!desc) {
> + log_err("Block device not found\n");
> + return -ENODEV;
> + }
> +
> + return gpt_get_mdata(desc, mdata);
> +}
> +
> +int fwu_get_mdata_device(struct udevice *dev, struct udevice **mdata_dev)

Function could be static (and declaration removed from fwu.h).

> +{
> + u32 phandle;
> + int ret, size;
> + struct udevice *parent, *child;
> + const fdt32_t *phandle_p = NULL;
> +
> + phandle_p = ofnode_get_property(dev_ofnode(dev), "fwu-mdata-store",
> + &size);

Should this be retrieved from driver's ::of_to_plat method?

Br,
etienne

> + if (!phandle_p) {
> + log_err("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;
> +
> + ret = -ENODEV;
> + for (device_find_first_child(parent, &child); child;
> + device_find_next_child(&child)) {
> + if (device_get_uclass_id(child) == UCLASS_BLK) {
> + *mdata_dev = child;
> + ret = 0;
> + }
> + }
> +
> + return ret;
> +}
> +
> +static int fwu_mdata_gpt_blk_probe(struct udevice *dev)
> +{
> + int ret;
> + struct udevice *mdata_dev = NULL;
> +
> + ret = fwu_get_mdata_device(dev, &mdata_dev);
> + if (ret)
> + return ret;
> +
> + dev_set_priv(dev, mdata_dev);
> +
> + return 0;
> +}
> +
> +static const struct fwu_mdata_ops fwu_gpt_blk_ops = {
> + .mdata_check = 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,
> +};
> diff --git a/include/fwu.h b/include/fwu.h
> index f9e44e7b39..3b1ee4e83e 100644
> --- a/include/fwu.h
> +++ b/include/fwu.h
> @@ -39,6 +39,8 @@ int fwu_get_active_index(u32 *active_idx);
> int fwu_update_active_index(u32 active_idx);
> int fwu_get_image_alt_num(efi_guid_t *image_type_id, u32 update_bank,
> int *alt_num);
> +int fwu_get_mdata_device(struct udevice *dev, struct udevice **mdata_dev);
> +int fwu_verify_mdata(struct fwu_mdata *mdata, bool pri_part);
> int fwu_mdata_check(void);
> int fwu_revert_boot_index(void);
> int fwu_accept_image(efi_guid_t *img_type_id, u32 bank);
> --
> 2.25.1
>