Commit graph

3 commits

Author SHA1 Message Date
Heinrich Schuchardt
657bd30c6b rng: eliminate common.h include from RNG drivers
Usage of common.h is deprecated.

* Remove common.h from RNG drivers.
* Sort includes.
* Add time.h to sandbox driver.
* Add linux/types.h to rng.h to provide size_t.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
2024-03-02 12:26:19 -05:00
Heinrich Schuchardt
badef4cd4a rng: fix ARMv8.5 RNDR driver
In different parts of our code we assume that the first RNG device is the
one to be used. Therefore it is preferable to detect the availability of
the RNDR register already in the bind method.

For signaling the non-existence of a device the driver model requires using
ENOENT (and not ENODEV).

Fixes: 31565bb0aa ("driver: rng: Add DM_RNG interface for ARMv8.5 RNDR registers")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
2024-01-09 07:36:18 +01:00
Andre Przywara
31565bb0aa driver: rng: Add DM_RNG interface for ARMv8.5 RNDR registers
The ARMv8.5 architecture extension defines architectural RNDR/RNDRRS
system registers, that provide 64 bits worth of randomness on every
read. Since it's an extension, and implementing it is optional, there is
a field in the ID_AA64ISAR0_EL1 ID register to query the availability
of those registers.

Add a UCLASS_RNG driver that returns entropy via repeated reads from
those system registers, if the extension is implemented.
The driver always binds, but checks the availability in the probe()
routine.

This helps systems which suffer from low boot entropy, since U-Boot can
provide entropy via the generic UEFI entropy gathering protocol to the OS,
at an early stage.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2023-10-11 13:22:32 -04:00