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

[Etienne Carriere <etienne.carriere@linaro.org>]

Hello Sughosh and all,

On Mon, 26 Sept 2022 at 10:46, Sughosh Ganu <sughosh.ganu@linaro.org> wrote:
>
> hi Ilias,
>
> On Thu, 22 Sept 2022 at 14:16, Ilias Apalodimas
> <ilias.apalodimas@linaro.org> wrote:
> >
> > 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.

By the way, drop HAVE_BLOCK_DEVICE that is no more needed here.
See https://source.denx.de/u-boot/u-boot/-/commit/7f8967c2b82f9917987b69fbf43f8f591f3a8516

> > > 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

I don't agree. If the function returns an error code, caller shall not
use the output content.
That is what callers of gpt_get_mdata_partitions() do in this patch,
so returning -EINVAL if fine.
(note that I don't mind this gets an array ref rather than 2 pointers).

best regards,
etienne

> > 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:
>
> Okay, will make use of the array as you suggest.
>
> >
> > 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.
>
> Sorry, I do not get this part.

>
> >
> >
> > > +
> > > +     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)?
>
> Will change
>
> > > +     }
> > > +
> > > +     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
>
> Will change
>
> -sughosh
>
> >
> > > +             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