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>

1 files changed, 26 insertions, 1 deletions

diff --git a/Documentation/arm64/memory.txt b/Documentation/arm64/memory.txt
index f28899d5c83e..5e054bfe4dde 100644
--- a/Documentation/arm64/memory.txt
+++ b/Documentation/arm64/memory.txt
@@ -21,7 +21,7 @@ The swapper_pgd_dir address is written to TTBR1 and never written to
 TTBR0.
 
 
-AArch64 Linux memory layout:
+AArch64 Linux memory layout with 4KB pages:
 
 Start                   End                     Size            Use
 -----------------------------------------------------------------------
@@ -46,6 +46,31 @@ ffffffbffc000000	ffffffbfffffffff	  64MB		modules
 ffffffc000000000        ffffffffffffffff         256GB          kernel logical memory map
 
 
+AArch64 Linux memory layout with 64KB pages:
+
+Start                   End                     Size            Use
+-----------------------------------------------------------------------
+0000000000000000        000003ffffffffff           4TB          user
+
+fffffc0000000000        fffffdfbfffeffff          ~2TB          vmalloc
+
+fffffdfbffff0000        fffffdfbffffffff          64KB          [guard page]
+
+fffffdfc00000000        fffffdfdffffffff           8GB          vmemmap
+
+fffffdfe00000000        fffffdfffbbfffff          ~8GB          [guard, future vmmemap]
+
+fffffdfffbc00000        fffffdfffbdfffff           2MB          earlyprintk device
+
+fffffdfffbe00000        fffffdfffbe0ffff          64KB          PCI I/O space
+
+fffffdfffbe10000        fffffdfffbffffff          ~2MB          [guard]
+
+fffffdfffc000000        fffffdffffffffff          64MB          modules
+
+fffffe0000000000        ffffffffffffffff           2TB          kernel logical memory map
+
+
 Translation table lookup with 4KB pages:
 
 +--------+--------+--------+--------+--------+--------+--------+--------+