[PATCH 5/9] x86/mm: Initialize vmemmap_base at boot-time

From: Kirill A. Shutemov
Date: Wed Feb 14 2018 - 13:27:15 EST


vmemmap area has different placement depending on paging mode.
Let's adjust it during early boot accodring to machine capability.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/pgtable_64_types.h | 9 +++------
arch/x86/kernel/head64.c | 3 ++-
2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h
index 686329994ade..68909a68e5b9 100644
--- a/arch/x86/include/asm/pgtable_64_types.h
+++ b/arch/x86/include/asm/pgtable_64_types.h
@@ -108,11 +108,8 @@ extern unsigned int ptrs_per_p4d;
#define VMALLOC_SIZE_TB_L4 32UL
#define VMALLOC_SIZE_TB_L5 12800UL

-#ifdef CONFIG_X86_5LEVEL
-# define __VMEMMAP_BASE _AC(0xffd4000000000000, UL)
-#else
-# define __VMEMMAP_BASE _AC(0xffffea0000000000, UL)
-#endif
+#define __VMEMMAP_BASE_L4 0xffffea0000000000
+#define __VMEMMAP_BASE_L5 0xffd4000000000000

#ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT
# define VMALLOC_START vmalloc_base
@@ -121,7 +118,7 @@ extern unsigned int ptrs_per_p4d;
#else
# define VMALLOC_START __VMALLOC_BASE_L4
# define VMALLOC_SIZE_TB VMALLOC_SIZE_TB_L4
-# define VMEMMAP_START __VMEMMAP_BASE
+# define VMEMMAP_START __VMEMMAP_BASE_L4
#endif /* CONFIG_DYNAMIC_MEMORY_LAYOUT */

#define VMALLOC_END (VMALLOC_START + (VMALLOC_SIZE_TB << 40) - 1)
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 22bf2015254c..795e762f3c66 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -53,7 +53,7 @@ unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE_L4;
EXPORT_SYMBOL(page_offset_base);
unsigned long vmalloc_base __ro_after_init = __VMALLOC_BASE_L4;
EXPORT_SYMBOL(vmalloc_base);
-unsigned long vmemmap_base __ro_after_init = __VMEMMAP_BASE;
+unsigned long vmemmap_base __ro_after_init = __VMEMMAP_BASE_L4;
EXPORT_SYMBOL(vmemmap_base);
#endif

@@ -88,6 +88,7 @@ static void __head check_la57_support(unsigned long physaddr)
*fixup_int(&ptrs_per_p4d, physaddr) = 512;
*fixup_long(&page_offset_base, physaddr) = __PAGE_OFFSET_BASE_L5;
*fixup_long(&vmalloc_base, physaddr) = __VMALLOC_BASE_L5;
+ *fixup_long(&vmemmap_base, physaddr) = __VMEMMAP_BASE_L5;
}
#else
static void __head check_la57_support(unsigned long physaddr) {}
--
2.15.1