Re: [PATCH v10 03/15] FWU: Add FWU metadata access driver for GPT partitioned block devices

Hi Sughosh

On Thu, Sep 15, 2022 at 01:44:39PM +0530, Sughosh Ganu 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 V9:

• s/formated/formatted in the commit message
• Add a '\n' character in the log message

drivers/fwu-mdata/Kconfig | 16 ++ drivers/fwu-mdata/Makefile | 8 + drivers/fwu-mdata/gpt_blk.c | 378 ++++++++++++++++++++++++++++++++++++ include/fwu.h | 4 + 4 files changed, 406 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..7322da48b1 --- /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 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 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..df115575e0 --- /dev/null +++ b/drivers/fwu-mdata/gpt_blk.c @@ -0,0 +1,378 @@ +// 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 *primary_mpart,
  

• 		    uint *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_debug("Expect two copies of the FWU metadata instead of %d\n",
  

• 	  mdata_parts);
  

• ret = -EINVAL;
  

• } else {

• ret = 0;
  

• }

Can we change that a bit? There are are some assumptions in this code, e.g the user must pass the values zero'ed out. Can we instead get an array of 2 instead? In that case you don't care if any of the values are zero and you can just fill in the array. Something like:

if (!guidcmp(&fwu_mdata_guid, &part_type_guid)) { array[mdata_parts] = i; mdata_parts++; You can also move the check in that if and make the func a lot easier to read.

• 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 primary_mpart = 0, secondary_mpart = 0;
• 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, &primary_mpart,

• 		       &secondary_mpart);
  

• 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, primary_mpart);
• 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, secondary_mpart);
• 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 primary_mpart = 0, secondary_mpart = 0;
• ret = gpt_get_mdata_partitions(desc, &primary_mpart,

• 		       &secondary_mpart);
  

• if (ret < 0) {

• log_debug("Error getting the FWU metadata partitions\n");
  

• return -ENOENT;
  

• }
• ret = gpt_read_mdata(desc, mdata, primary_mpart);
• 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, secondary_mpart);
• 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 primary_mpart = 0, secondary_mpart = 0;
• 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, &primary_mpart,

• 		       &secondary_mpart);
  

• if (ret < 0) {

• log_debug("Error getting the FWU metadata partitions\n");
  

• return -ENOENT;
  

• }
• ret = gpt_read_mdata(desc, &pri_mdata, primary_mpart);
• if (ret < 0) {

• log_debug("Failed to read the FWU metadata from the device\n");
  

• goto secondary_read;
  

Can't we skip the goto here and just make the if above (if ret == 0)?

• }
• 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_debug("Failed to read the FWU metadata from the device\n");
  

Same here

• 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_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;
  

• 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_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) +{

• /*

• * 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);

+}

+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 = {

• .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,
• .priv_auto = sizeof(struct fwu_mdata_gpt_blk_priv),

+}; diff --git a/include/fwu.h b/include/fwu.h index 745f6225d0..1e16253f69 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

Cheers /Ilias