This reverts commit 45f41c134baf5ff1bbf59d33027f6c79884fa4d9.
This weird workaround was the best I came up with at that time
to boot U-Boot from TF-A.
I noticed U-Boot successfully boots on LD20 (i.e. CA72 CPU) by using
the latest TF-A.
Specifically, since the following TF-A commit, U-Boot runs at EL2
instead of EL1, and this issue went away as a side-effect.
|commit f998a052fd94ea082833109f25b94ed5bfa24e8b
|Author: Masahiro Yamada <yamada.masah...@socionext.com>
|Date: Thu Jul 25 10:57:38 2019 +0900
|
| uniphier: run BL33 at EL2
|
| All the SoCs in 64-bit UniPhier SoC family support EL2.
|
| Just hard-code MODE_EL2 instead of using el_implemented() helper.
|
| Change-Id: I7ab48002c5205bc8c013e1b46313b57d6c431db0
| Signed-off-by: Masahiro Yamada <yamada.masah...@socionext.com>
However, if I reverted that, this problem would come back, presumably
because some EL1 code in U-Boot triggers this issue.
Now that commit f8ddd8cbb513 ("arm64: issue ISB after updating system
registers") fixed this issue properly, this weird workaround is no
longer needed irrespective of the exception level at which U-Boot runs.
Signed-off-by: Masahiro Yamada <yamada.masah...@socionext.com>
---
arch/arm/mach-uniphier/arm64/Makefile | 1 -
arch/arm/mach-uniphier/arm64/lowlevel_init.S | 13 -------------
2 files changed, 14 deletions(-)
delete mode 100644 arch/arm/mach-uniphier/arm64/lowlevel_init.S
diff --git a/arch/arm/mach-uniphier/arm64/Makefile
b/arch/arm/mach-uniphier/arm64/Makefile
index c569551120..750c4f756e 100644
--- a/arch/arm/mach-uniphier/arm64/Makefile
+++ b/arch/arm/mach-uniphier/arm64/Makefile
@@ -1,4 +1,3 @@
# SPDX-License-Identifier: GPL-2.0+
obj-y += mem_map.o
-obj-$(CONFIG_ARCH_UNIPHIER_LD20) += lowlevel_init.o
diff --git a/arch/arm/mach-uniphier/arm64/lowlevel_init.S
b/arch/arm/mach-uniphier/arm64/lowlevel_init.S
deleted file mode 100644
index f4e5cbbbd1..0000000000
--- a/arch/arm/mach-uniphier/arm64/lowlevel_init.S
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0+ */
-/*
- * Copyright (C) 2017 Socionext Inc.
- */
-
-#include <linux/linkage.h>
-
-ENTRY(lowlevel_init)
- /* LD20 needs the following code to boot. I do not know why. */
- mrs x0, sctlr_el1
- msr sctlr_el1, x0
- ret
-ENDPROC(lowlevel_init)
--
2.25.1
