Re: [PATCH v9 03/15] FWU: Add FWU metadata access driver for GPT partitioned block devices

Sughosh Ganu
2022-09-06T07:13:03Z

hi Etienne,

On Tue, 6 Sept 2022 at 12:31, Etienne Carriere
<etienne.carriere@linaro.org> wrote:
>
> Hi Sughosh,
>
> Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org> with
> comment addressed.

Will address both your review comments. Thanks.

-sughosh

>
>
> On Fri, 26 Aug 2022 at 11:57, 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.
>
> formatted
>
> >
> > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> > Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
> > ---
> > Changes since V8:
> > * Rename fwu_mdata_gpt_blk.c as gpt_blk.c as suggested by Simon
> > * Use natural integer types instead of specific width integers as
> > suggested by Simon
> > * Fix return codes as suggested by Simon
> > * Code cleanup of some superfluous error checks, like for
> > dev_get_uclass_plat() function
> > * Use blk_get_from_parent() for getting the parent of the block device
> > containing the FWU metadata
> > * Add comments to the API functions
> >
> > 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..4f0558825b
> > --- /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;
> > + }
> > +
> > + 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",
>
> missing terminal '\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;
> > + }
> > +
> > + 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");
> > + 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 2335981d28..ecabf11210 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
> >