The state framework grew organically over the time. Unfortunately the
architecture and abstractions disappeared during this period.
This patch refactors the framework to recreate the abstractions. The
main focus was the backend with its storage. The main use-case was to
offer better NAND support with less erase cycles and interchangeable
data formats (dtb,raw).
The general architecture now has a backend which consists of a data
format and storage. The storage consists of multiple storage buckets
each holding exactly one copy of the state data. A data format describes
a data serialization for the state framework. This can be either dtb or
raw. A storage bucket is a storage location which is used to store any
data. There is a (new) circular type which writes changes behind the
last written data and therefore reduces the number of erases. The other
type is a direct bucket which writes directly to a storage offset for
all non-erase storage.
Furthermore this patch splits up all classes into different files in a
subdirectory.
This is currently all in one patch as I can't see a good way to split
the changes up without having a non-working state framework in between.
The following diagram shows the new architecture roughly:
.----------.
| state |
'----------'
|
|
v
.----------------------------.
| state_backend |
|----------------------------|
| + state_load(*state); |
| + state_save(*state); |
| + state_backend_init(...); |
| |
| |
'----------------------------'
| | The format describes
| | how the state data
| '-------------> is serialized
| .--------------------------------------------.
| | state_backend_format <INTERFACE> |
| |--------------------------------------------|
| | + verify(*format, magic, *buf, len); |
| | + pack(*format, *state, **buf, len); |
| | + unpack(*format, *state, *buf, len); |
| | + get_packed_len(*format, *state); |
| | + free(*format); |
| '--------------------------------------------'
| ^ ^
| * *
| * *
| .--------------------. .--------------------.
| | backend_format_dtb | | backend_format_raw |
| '--------------------' '--------------------'
|
|
|
v
.----------------------------------------------------------.
| state_backend_storage |
|----------------------------------------------------------|
| + init(...); |
| + free(*storage); |
| + read(*storage, *format, magic, **buf, *len, len_hint); |
| + write(*storage, *buf, len); |
| + restore_consistency(*storage, *buf, len); |
'----------------------------------------------------------'
|
The backend storage is responsible to manage multiple
data copies and distribute them onto several buckets.
Read data is verified against the given format to
ensure that the read data is correct.
|
|
|
|
|
v
.------------------------------------------.
| state_backend_storage_bucket <INTERFACE> |
|------------------------------------------|
| + init(*bucket); |
| + write(*bucket, *buf, len); |
| + read(*bucket, **buf, len_hint); |
| + free(*bucket); |
'------------------------------------------'
^ ^ ^
* * *
* * *
A storage bucket represents*exactly one data copy at one
data location. A circular b*cket writes any new data to
the end of the bucket (for *educed erases on NAND). A
direct bucket directly writ*s at one location.
* * *
* * *
* * *
.-----------------------. * .-------------------------.
| backend_bucket_direct | * | backend_bucket_circular |
'-----------------------' * '-------------------------'
^ * ^
| * |
| * |
| * |
| .-----------------------. |
'--| backend_bucket_cached |---'
'-----------------------'
A backend_bucket_cached is a transparent
bucket that directly uses another bucket
as backend device and caches all accesses.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Explicitly loading environment is not required as it will be loaded if
available during device probing
Signed-off-by: Enrico Jorns <ejo@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This patch improves the backend property, it can be either a phandle or a
of_path. During probe() of the state driver the backend property is
dereferenced and the resulting of_path is saved in the state context. In a
later patch it will be used to generate a phandle reference to the backend
during DT fixup.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Otherwise compilation may fail with:
include/fdt.h:11:15: error: unknown type name 'uint64_t'
static inline uint64_t fdt64_to_cpu(uint64_t x)
include/of.h:22:19: error: field 'list' has incomplete type
struct list_head list;
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This patch adds a framework to describe, access, store and restore a set of
variables. A state variable set can be fully described in a devicetree node.
This node could be part of the regular devicetree blob or it could be an extra
devicetree solely for the state. The state variable set contains variables of
different types and a place to store the variable set.
For more information see:
Documentation/devicetree/bindings/barebox/barebox,state.rst
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Markus Pargmann
Enrico Jorns
Marc Kleine-Budde
Sascha Hauer