On 31.05.23 22:01, Marco Felsch wrote:
> Hi Ahmad,
>
> On 23-05-31, Ahmad Fatoum wrote:
>> The backend device tree property so far always pointed at a partition.
>> Let's allow pointing it at GPT storage devices directly and lookup
>> the correct barebox state partition by the well-known type GUID:
>>
>> 4778ed65-bf42-45fa-9c5b-287a1dc4aab1
>
> we should add an example within the Documetation/ too.
I'd wait until we have a new dt-utils release with the same
binding. Anything else would be confusing.
>
>> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
>> ---
>> common/state/state.c | 22 ++++++++++++++++++++++
>> include/driver.h | 17 +++++++++++++++++
>> include/state.h | 4 ++++
>> 3 files changed, 43 insertions(+)
>>
>> diff --git a/common/state/state.c b/common/state/state.c
>> index 88e246198fb8..8f56c60b0e82 100644
>> --- a/common/state/state.c
>> +++ b/common/state/state.c
>> @@ -21,8 +21,10 @@
>> #include <fs.h>
>> #include <crc.h>
>> #include <init.h>
>> +#include <block.h>
>> #include <linux/err.h>
>> #include <linux/list.h>
>> +#include <linux/uuid.h>
>>
>> #include <linux/mtd/mtd-abi.h>
>> #include <malloc.h>
>> @@ -595,6 +597,8 @@ static char *cdev_to_devpath(struct cdev *cdev, off_t *offset, size_t *size)
>> }
>> #endif
>>
>> +static guid_t barebox_state_partition_guid = BAREBOX_STATE_PARTITION_GUID;
>> +
>> /*
>> * state_new_from_node - create a new state instance from a device_node
>> *
>> @@ -641,6 +645,24 @@ struct state *state_new_from_node(struct device_node *node, bool readonly)
>> goto out_release_state;
>> }
>>
>> + /* Is the backend referencing an on-disk partitonable block device? */
>> + if (cdev_is_block_disk(cdev)) {
>> + struct cdev *partcdev = NULL;
>> +
>> + if (cdev_is_gpt_partitioned(cdev))
>> + partcdev = cdev_find_child_by_typeuuid(cdev, &barebox_state_partition_guid);
>> +
>> + if (!partcdev) {
>> + ret = -EINVAL;
>> + goto out_release_state;
>> + }
>> +
>> + pr_debug("%s: backend GPT partition looked up via PartitionTypeGUID\n",
>> + node->full_name);
>> +
>> + cdev = partcdev;
>> + }
>
> What about having the above logic within a seperate function and the
> above code would be:
>
> if (cdev_is_block_disk(cdev))
> cdev = get_cdev_by_typeuuid(cdev, &barebox_state_partition_guid)
>
> if (!cdev) {
> ret = -EINVAL;
> goto out_release_state;
> }
>
> This way we would have everything in place to re-use the same logic for
> the barebox-environmnet too. What do you think?
cdev from of_cdev_find not being available -> -EPROBE_DEFER
cdev GPT partition not existing,despite backend pointing at root device -> -EINVAL
So the cdev check needs to be within if (cdev_is_block_disk(cdev)).
I don't object to combining cdev_is_gpt_partitioned and cdev_find_child_by_typeuuid into
cdev_find_child_by_gpt_typeuuid though.
Thanks for all the review!
Ahmad
>
> Regards,
> Marco
>
>> +
>> state->backend_path = cdev_to_devpath(cdev, &offset, &size);
>>
>> pr_debug("%s: backend resolved to %s\n", node->full_name, state->backend_path);
>> diff --git a/include/driver.h b/include/driver.h
>> index 6407f7d6ba36..579b03fbac34 100644
>> --- a/include/driver.h
>> +++ b/include/driver.h
>> @@ -585,6 +585,23 @@ extern struct list_head cdev_list;
>> #define for_each_cdev(cdev) \
>> list_for_each_entry(cdev, &cdev_list, list)
>>
>> +#define for_each_cdev_partition(partcdev, cdev) \
>> + list_for_each_entry((partcdev), &(cdev)->partitions, partition_entry)
>> +
>> +
>> +static inline struct cdev *cdev_find_child_by_typeuuid(struct cdev *cdev,
>> + guid_t *typeuuid)
>> +{
>> + struct cdev *partcdev;
>> +
>> + for_each_cdev_partition(partcdev, cdev) {
>> + if (guid_equal(&partcdev->typeuuid, typeuuid))
>> + return partcdev;
>> + }
>> +
>> + return NULL;
>> +}
>> +
>> #define DEVFS_PARTITION_FIXED (1U << 0)
>> #define DEVFS_PARTITION_READONLY (1U << 1)
>> #define DEVFS_IS_CHARACTER_DEV (1U << 3)
>> diff --git a/include/state.h b/include/state.h
>> index bffcd5a9007f..3daf82c0735f 100644
>> --- a/include/state.h
>> +++ b/include/state.h
>> @@ -62,4 +62,8 @@ static inline int state_read_mac(struct state *state, const char *name, u8 *buf)
>>
>> #endif /* #if IS_ENABLED(CONFIG_STATE) / #else */
>>
>> +#define BAREBOX_STATE_PARTITION_GUID \
>> + GUID_INIT(0x4778ed65, 0xbf42, 0x45fa, 0x9c, 0x5b, \
>> + 0x28, 0x7a, 0x1d, 0xc4, 0xaa, 0xb1)
>> +
>> #endif /* __STATE_H */
>> --
>> 2.39.2
>>
>>
>>
>
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