Re: [PATCH v9 06/15] FWU: Add helper functions for accessing FWU metadata

Sughosh Ganu
2022-09-07T11:06:14Z

hi Ilias,

On Wed, 7 Sept 2022 at 11:29, Ilias Apalodimas
<ilias.apalodimas@linaro.org> wrote:
>
> On Fri, Aug 26, 2022 at 03:27:07PM +0530, Sughosh Ganu wrote:
> > Add weak functions for getting the update index value and dfu
> > alternate number needed for FWU Multi Bank update
> > functionality.
> >
> > The current implementation for getting the update index value is for
> > platforms with 2 banks. If a platform supports more than 2 banks, it
> > can implement it's own function. The function to get the dfu alternate
> > number has been added for platforms with GPT partitioned storage
> > devices. Platforms with other storage partition scheme need to
> > implement their own function.
> >
> > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> > Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
> > ---
> > Changes since V8:
> > * Add comments for API functions
> > * Update the logic to get the update index as suggested by Jassi
> >
> > include/fwu.h | 29 ++++++++++
> > lib/fwu_updates/fwu.c | 27 +++++++++
> > lib/fwu_updates/fwu_gpt.c | 115 ++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 171 insertions(+)
> > create mode 100644 lib/fwu_updates/fwu_gpt.c
> >
> > diff --git a/include/fwu.h b/include/fwu.h
> > index ecabf11210..7ebd3a7115 100644
> > --- a/include/fwu.h
> > +++ b/include/fwu.h
> > @@ -211,4 +211,33 @@ int fwu_accept_image(efi_guid_t *img_type_id, u32 bank);
> > */
> > int fwu_clear_accept_image(efi_guid_t *img_type_id, u32 bank);
> >
> > +/**
> > + * fwu_plat_get_alt_num() - Get the DFU Alt Num for the image from the platform
> > + * @dev: FWU device
> > + * @image_guid: Image GUID for which DFU alt number needs to be retrieved
> > + * @alt_num: Pointer to the alt_num
> > + *
> > + * Get the DFU alt number from the platform for the image specified by the
> > + * image GUID.
> > + *
> > + * Return: 0 if OK, -ve on error
> > + *
> > + */
> > +int fwu_plat_get_alt_num(struct udevice *dev, efi_guid_t *image_guid,
> > + int *alt_num);
> > +
> > +/**
> > + * fwu_plat_get_update_index() - Get the value of the update bank
> > + * @update_idx: Bank number to which images are to be updated
> > + *
> > + * Get the value of the bank(partition) to which the update needs to be
> > + * made.
> > + *
> > + * Note: This is a weak function and platforms can override this with
> > + * their own implementation for selection of the update bank.
> > + *
> > + * Return: 0 if OK, -ve on error
> > + *
> > + */
> > +int fwu_plat_get_update_index(uint *update_idx);
> > #endif /* _FWU_H_ */
> > diff --git a/lib/fwu_updates/fwu.c b/lib/fwu_updates/fwu.c
> > index a871d77b4c..94b15859a5 100644
> > --- a/lib/fwu_updates/fwu.c
> > +++ b/lib/fwu_updates/fwu.c
> > @@ -355,3 +355,30 @@ int fwu_clear_accept_image(efi_guid_t *img_type_id, u32 bank)
> > return fwu_clrset_image_accept(img_type_id, bank,
> > IMAGE_ACCEPT_CLEAR);
> > }
> > +
> > +/**
> > + * fwu_plat_get_update_index() - Get the value of the update bank
> > + * @update_idx: Bank number to which images are to be updated
> > + *
> > + * Get the value of the bank(partition) to which the update needs to be
> > + * made.
> > + *
> > + * Note: This is a weak function and platforms can override this with
> > + * their own implementation for selection of the update bank.
> > + *
> > + * Return: 0 if OK, -ve on error
> > + *
> > + */
> > +__weak int fwu_plat_get_update_index(uint *update_idx)
> > +{
> > + int ret;
> > + u32 active_idx;
> > +
> > + ret = fwu_get_active_index(&active_idx);
> > + if (ret < 0)
> > + return -1;
> > +
> > + *update_idx = (active_idx + 1) % CONFIG_FWU_NUM_BANKS;
> > +
> > + return ret;
> > +}
> > diff --git a/lib/fwu_updates/fwu_gpt.c b/lib/fwu_updates/fwu_gpt.c
> > new file mode 100644
> > index 0000000000..a3134b80c9
> > --- /dev/null
> > +++ b/lib/fwu_updates/fwu_gpt.c
> > @@ -0,0 +1,115 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Copyright (c) 2022, Linaro Limited
> > + */
> > +
> > +#include <blk.h>
> > +#include <dfu.h>
> > +#include <efi.h>
> > +#include <efi_loader.h>
> > +#include <fwu.h>
> > +#include <log.h>
> > +#include <part.h>
> > +
> > +#include <linux/errno.h>
> > +
> > +static int get_gpt_dfu_identifier(struct blk_desc *desc, efi_guid_t *image_guid)
> > +{
> > + int i;
> > + struct disk_partition info;
> > + efi_guid_t unique_part_guid;
> > +
> > + for (i = 1; i < MAX_SEARCH_PARTITIONS; i++) {
> > + if (part_get_info(desc, i, &info))
> > + continue;
> > + uuid_str_to_bin(info.uuid, unique_part_guid.b,
> > + UUID_STR_FORMAT_GUID);
> > +
> > + if (!guidcmp(&unique_part_guid, image_guid))
> > + return i;
> > + }
> > +
> > + log_err("No partition found with image_guid %pUs\n", image_guid);
> > + return -ENOENT;
> > +}
> > +
> > +static int fwu_gpt_get_alt_num(struct blk_desc *desc, efi_guid_t *image_guid,
> > + int *alt_num, unsigned char dfu_dev)
> > +{
> > + int ret = -1;
> > + int i, part, dev_num;
> > + int nalt;
> > + struct dfu_entity *dfu;
> > +
> > + dev_num = desc->devnum;
> > + part = get_gpt_dfu_identifier(desc, image_guid);
> > + if (part < 0)
> > + return -ENOENT;
> > +
> > + dfu_init_env_entities(NULL, NULL);
> > +
> > + nalt = 0;
> > + list_for_each_entry(dfu, &dfu_list, list) {
> > + nalt++;
> > + }
>
> Nit, you don't need {}

Will remove

>
> > +
> > + if (!nalt) {
> > + log_warning("No entities in dfu_alt_info\n");
> > + dfu_free_entities();
> > + return -ENOENT;
> > + }
> > +
> > + for (i = 0; i < nalt; i++) {
> > + dfu = dfu_get_entity(i);
> > +
> > + if (!dfu)
> > + continue;
> > +
> > + /*
> > + * Currently, Multi Bank update
> > + * feature is being supported
> > + * only on GPT partitioned
> > + * MMC/SD devices.
> > + */
> > + if (dfu->dev_type != dfu_dev)
> > + continue;
> > +
> > + if (dfu->layout == DFU_RAW_ADDR &&
> > + dfu->data.mmc.dev_num == dev_num &&
> > + dfu->data.mmc.part == part) {
> > + *alt_num = dfu->alt;
> > + ret = 0;
>
> Can we make this function return the partition number and < 0 on failure?
> If it's too big of a change, I don't mind keeping it as is

If you don't have a strong opinion on this, I would prefer to keep it
as is, since this is consistent with the behaviour of the other
functions where the value is being obtained through a pointer and the
function is returning the status.

-sughosh

>
> Regards
> /Ilias
> > + break;
> > + }
> > + }
> > +
> > + dfu_free_entities();
> > +
> > + return ret;
> > +}
> > +
> > +/**
> > + * fwu_plat_get_alt_num() - Get the DFU alt number
> > + * @dev: FWU metadata device
> > + * @image_guid: GUID value of the image for which the alt num is to
> > + * be obtained
> > + * @alt_num: The DFU alt number for the image that is to be updated
> > + *
> > + * Get the DFU alt number for the image that is to be updated. The
> > + * image is identified with the image_guid parameter that is passed
> > + * to the function.
> > + *
> > + * Note: This is a weak function and platforms can override this with
> > + * their own implementation for obtaining the alt number value.
> > + *
> > + * Return: 0 if OK, -ve on error
> > + *
> > + */
> > +__weak int fwu_plat_get_alt_num(struct udevice *dev, efi_guid_t *image_guid,
> > + int *alt_num)
> > +{
> > + struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
> > +
> > + return fwu_gpt_get_alt_num(dev_get_uclass_plat(priv->blk_dev),
> > + image_guid, alt_num, DFU_DEV_MMC);
> > +}
> > --
> > 2.34.1
> >