meta-arm/meta-arm-bsp/recipes-bsp/u-boot/u-boot/tc/0007-arm_ffa-unmap-rxtx-buffer-before-exiting-u-boot.patch

From 47be0456ea1760837d2de857e57842e595e9ea5e Mon Sep 17 00:00:00 2001
From: Davidson K <davidson.kumaresan@arm.com>
Date: Mon, 27 Jun 2022 14:11:27 +0530
Subject: [PATCH 7/7] arm_ffa: unmap rxtx buffer before exiting u-boot

The linux kernel ffa driver will be used after the kernel boots. It
will try to map its own rxtx buffer. But there can be only one rxtx
buffer mapped from the non secure world. Since the rxtx buffer of
the u-boot is no longer used and we have to map the rxtx buffer of
the linux kernel, the rxtx buffer of the u-boot should be unmapped.

This will not be needed after the efi runtime services are enabled

Signed-off-by: Davidson K <davidson.kumaresan@arm.com>
Change-Id: I9deb6283d81f791185aa0a32d205b394d6d91f76
Upstream-Status: Pending [Not submitted to upstream yet]
---
 drivers/arm-ffa/core.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/arm-ffa/core.c b/drivers/arm-ffa/core.c
index 98e2d2fa17..0c619439cb 100644
--- a/drivers/arm-ffa/core.c
+++ b/drivers/arm-ffa/core.c
@@ -1470,6 +1470,16 @@ static const struct udevice_id ffa_match_id[] = {
 	{},
 };
 
+/**
+ * Unmap the rxtx buffer before exiting u-boot
+ * This avoids conflicts with the linux kernel ffa driver
+ */
+
+static int ffa_remove(struct udevice *dev)
+{
+	return ffa_unmap_rxtx_buffers();
+}
+
 /**
  * Declaring the arm_ffa driver under UCLASS_FFA
  */
@@ -1481,4 +1491,6 @@ U_BOOT_DRIVER(arm_ffa) = {
 	.of_to_plat	= ffa_of_to_plat,
 	.probe		= ffa_probe,
 	.plat_auto	= sizeof(struct ffa_pdata),
+	.remove		= ffa_remove,
+	.flags		= DM_FLAG_OS_PREPARE,
 };
-- 
2.34.1