Re: [PATCH v6 04/10] arm_ffa: efi: unmap RX/TX buffers

Ilias Apalodimas
2022-10-24T12:09:04Z

On Thu, Oct 13, 2022 at 11:38:51AM +0100, Abdellatif El Khlifi wrote:
> unmap RX/TX buffers at ExitBootServices()
>
> Unmapping the RX/TX buffers created by u-boot is needed before EFI
> runtime.
>
> At EFI runtime the linux kernel takes care of allocating its own RX/TX
> buffers and registering them with the secure world.
>
> Secure world should be using the RX/TX buffers created by the kernel.
> So, RX/TX buffers created by u-boot must be unmapped.
>
> Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Simon Glass <sjg@chromium.org>
> Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> Cc: Jens Wiklander <jens.wiklander@linaro.org>
> ---
> lib/efi_loader/efi_boottime.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index a56021559b..2054b33568 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -3,6 +3,9 @@
> * EFI application boot time services
> *
> * Copyright (c) 2016 Alexander Graf
> + *
> + * (C) Copyright 2022 ARM Limited
> + * Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
> */
>
> #include <common.h>
> @@ -23,6 +26,10 @@
> #include <asm/setjmp.h>
> #include <linux/libfdt_env.h>
>
> +#if CONFIG_IS_ENABLED(ARM_FFA_TRANSPORT)
> +#include <arm_ffa.h>
> +#endif
> +
> DECLARE_GLOBAL_DATA_PTR;
>
> /* Task priority level */
> @@ -2178,6 +2185,14 @@ static efi_status_t EFIAPI efi_exit_boot_services(efi_handle_t image_handle,
> dm_remove_devices_flags(DM_REMOVE_ACTIVE_ALL);
> }
>
> +#if CONFIG_IS_ENABLED(ARM_FFA_TRANSPORT)
> + /* unmap FF-A RX/TX buffers */
> + if (ffa_bus_ops_get()->rxtx_unmap())
> + debug("[efi_boottime][ERROR]: can not unmap FF-A RX/TX buffers\n");

Just do log_err() here and get rid of the else

> + else
> + debug("[efi_boottime][INFO]: FF-A RX/TX buffers unmapped\n");
> +#endif
> +
> /* Patch out unsupported runtime function */
> efi_runtime_detach();
>
> --
> 2.17.1
>

Thanks
/Ilias