From 2bb9839e312ed55a6d5824ffa6077ce3d7d63b1e Mon Sep 17 00:00:00 2001
From: Nicolas Pitre <nicolas.pitre@linaro.org>
Date: Tue, 5 Jul 2011 22:38:10 -0400
Subject: [PATCH] ARM: introduce atag_offset to replace boot_params
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The boot_params member of the mdesc structure is used to provide a
default physical address for the ATAG list. Since this value is fixed
at compile time and sometimes based on constants such as ARCH_PHYS_OFFSET,
it gets in the way of runtime PHYS_OFFSET and CONFIG_ARM_PATCH_PHYS_VIRT
usage.
Let's introduce atag_offset which should contains only the relative
offset from PHYS_OFFSET instead of an absolute value, in preparation
to move all instance of boot_params over to it.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Tested-by: Petr Å tetiar <ynezz@true.cz>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
arch/arm/include/asm/mach/arch.h | 1 +
arch/arm/kernel/setup.c | 2 ++
2 files changed, 3 insertions(+)
diff --git a/arch/arm/include/asm/mach/arch.h b/arch/arm/include/asm/mach/arch.h
index 217aa1911dd7..cc240c03efec 100644
--- a/arch/arm/include/asm/mach/arch.h
+++ b/arch/arm/include/asm/mach/arch.h
@@ -18,6 +18,7 @@ struct machine_desc {
unsigned int nr; /* architecture number */
const char *name; /* architecture name */
unsigned long boot_params; /* tagged list */
+ unsigned long atag_offset; /* tagged list (relative) */
const char **dt_compat; /* array of device tree
* 'compatible' strings */
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 70bca649e925..2737ba3f739c 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -819,6 +819,8 @@ static struct machine_desc * __init setup_machine_tags(unsigned int nr)
if (__atags_pointer)
tags = phys_to_virt(__atags_pointer);
+ else if (mdesc->atag_offset)
+ tags = (void *)(PAGE_OFFSET + mdesc->atag_offset);
else if (mdesc->boot_params) {
#ifdef CONFIG_MMU
/*
--
2.20.1