arm64: Use 42-bit address space with 64K pages
This patch expands the VA_BITS to 42 when the 64K page configuration is
enabled allowing 2TB kernel linear mapping. Linux still uses 2 levels of
page tables in this configuration with pgd now being a full page.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 847264fb7e73ade5b5e4b6eea3daa243a1f5217e)
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 381f556..9abb57d 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -33,18 +33,23 @@
#define UL(x) _AC(x, UL)
/*
- * PAGE_OFFSET - the virtual address of the start of the kernel image.
+ * PAGE_OFFSET - the virtual address of the start of the kernel image (top
+ * (VA_BITS - 1))
* VA_BITS - the maximum number of bits for virtual addresses.
* TASK_SIZE - the maximum size of a user space task.
* TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
* The module space lives between the addresses given by TASK_SIZE
* and PAGE_OFFSET - it must be within 128MB of the kernel text.
*/
-#define PAGE_OFFSET UL(0xffffffc000000000)
+#ifdef CONFIG_ARM64_64K_PAGES
+#define VA_BITS (42)
+#else
+#define VA_BITS (39)
+#endif
+#define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1))
#define MODULES_END (PAGE_OFFSET)
#define MODULES_VADDR (MODULES_END - SZ_64M)
#define EARLYCON_IOBASE (MODULES_VADDR - SZ_4M)
-#define VA_BITS (39)
#define TASK_SIZE_64 (UL(1) << VA_BITS)
#ifdef CONFIG_COMPAT