[PATCH v5 11/13] Revert "xen/arm: Remove unused BOOT_RELOC_VIRT_START"

[Carlo Nonato <carlo.nonato@xxxxxxxxxxxxxxx>]

This reverts commit 0c18fb76323bfb13615b6f13c98767face2d8097 (not clean).

This is not a clean revert since the rework of the memory layout, but it is
sufficiently similar to a clean one.
The only difference is that the BOOT_RELOC_VIRT_START must match the new
layout.

Cache coloring support for Xen needs to relocate Xen code and data in a new
colored physical space. The BOOT_RELOC_VIRT_START will be used as the virtual
base address for a temporary mapping to this new space.

Signed-off-by: Carlo Nonato <carlo.nonato@xxxxxxxxxxxxxxx>
Signed-off-by: Marco Solieri <marco.solieri@xxxxxxxxxxxxxxx>
---
 xen/arch/arm/include/asm/mmu/layout.h | 2 ++
 xen/arch/arm/mmu/setup.c              | 1 +
 2 files changed, 3 insertions(+)

diff --git a/xen/arch/arm/include/asm/mmu/layout.h 
b/xen/arch/arm/include/asm/mmu/layout.h
index eac7eef885..30031f74d9 100644
--- a/xen/arch/arm/include/asm/mmu/layout.h
+++ b/xen/arch/arm/include/asm/mmu/layout.h
@@ -74,6 +74,8 @@
 #define BOOT_FDT_VIRT_START     (FIXMAP_VIRT_START + FIXMAP_VIRT_SIZE)
 #define BOOT_FDT_VIRT_SIZE      _AT(vaddr_t, MB(4))
 
+#define BOOT_RELOC_VIRT_START   (BOOT_FDT_VIRT_START + BOOT_FDT_VIRT_SIZE)
+
 #ifdef CONFIG_LIVEPATCH
 #define LIVEPATCH_VMAP_START    (BOOT_FDT_VIRT_START + BOOT_FDT_VIRT_SIZE)
 #define LIVEPATCH_VMAP_SIZE    _AT(vaddr_t, MB(2))
diff --git a/xen/arch/arm/mmu/setup.c b/xen/arch/arm/mmu/setup.c
index d5264e51bc..37b6d230ad 100644
--- a/xen/arch/arm/mmu/setup.c
+++ b/xen/arch/arm/mmu/setup.c
@@ -69,6 +69,7 @@ static void __init __maybe_unused build_assertions(void)
     /* 2MB aligned regions */
     BUILD_BUG_ON(XEN_VIRT_START & ~SECOND_MASK);
     BUILD_BUG_ON(FIXMAP_ADDR(0) & ~SECOND_MASK);
+    BUILD_BUG_ON(BOOT_RELOC_VIRT_START & ~SECOND_MASK);
     /* 1GB aligned regions */
 #ifdef CONFIG_ARM_32
     BUILD_BUG_ON(XENHEAP_VIRT_START & ~FIRST_MASK);
-- 
2.34.1