[PATCH v2] firmware: arm_ffa: Add support for MEM_LEND

[Jens Wiklander]

On Fri, Oct 15, 2021 at 6:58 PM Marc Bonnici <marc.bonnici at arm.com> wrote:
>
> As part of the FF-A spec, an endpoint is allowed to
> transfer access of, or lend, a memory region to one
> or more borrowers.
>
> Extend the existing memory sharing implementation to
> support FF-A MEM_LEND functionality and expose this
> to other kernel drivers.
>
> Note that upon a successful MEM_LEND request the caller
> must ensure that the memory region specified is not accessed
> until a successful MEM_RECALIM call has been made.
> On systems with a hypervisor present this will been enforced,
> however on systems without a hypervisor the responsibility
> falls to the calling kernel driver to prevent access.
>
> Signed-off-by: Marc Bonnici <marc.bonnici at arm.com>
> ---
>  drivers/firmware/arm_ffa/driver.c | 17 +++++++++++++++++
>  include/linux/arm_ffa.h           |  2 ++
>  2 files changed, 19 insertions(+)

Reviewed-by: Jens Wiklander <jens.wiklander at linaro.org>