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

[Abdellatif El Khlifi]

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 at arm.com>
Cc: Tom Rini <trini at konsulko.com>
Cc: Simon Glass <sjg at chromium.org>
Cc: Ilias Apalodimas <ilias.apalodimas at linaro.org>
Cc: Jens Wiklander <jens.wiklander at 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 at 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");
+		else
+			debug("[efi_boottime][INFO]: FF-A RX/TX buffers unmapped\n");
+#endif
+
 	/* Patch out unsupported runtime function */
 	efi_runtime_detach();
 
-- 
2.17.1