[PATCH] Documentation/arm64: add memory layout with 4KB pages + VA39-bit

From: Jisheng Zhang
Date: Thu Sep 30 2021 - 06:50:47 EST


The 4KB pages + 3 levels (39-bit) combination is also widely used in
arm64 world, add the memory layout description for this combination.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
---
Documentation/arm64/memory.rst | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/Documentation/arm64/memory.rst b/Documentation/arm64/memory.rst
index 901cd094f4ec..d1745b570f0c 100644
--- a/Documentation/arm64/memory.rst
+++ b/Documentation/arm64/memory.rst
@@ -26,6 +26,23 @@ The swapper_pg_dir address is written to TTBR1 and never written to
TTBR0.


+AArch64 Linux memory layout with 4KB pages + 3 levels (39-bit)::
+ Start End Size Use
+ -----------------------------------------------------------------------
+ 0000000000000000 0000007fffffffff 512GB user
+ ffffff8000000000 ffffffbfffffffff 256GB kernel logical memory map
+ [ffffffb000000000 ffffffbfffffffff] 64GB [kasan shadow region]
+ ffffffc000000000 ffffffc007ffffff 128MB bpf jit region
+ ffffffc008000000 ffffffc00fffffff 128MB modules
+ ffffffc010000000 fffffffdefffffff 253440MB vmalloc
+ fffffffdf0000000 fffffffdfdffffff 224MB fixed mappings (top down)
+ fffffffdfe000000 fffffffdfe7fffff 8MB [guard region]
+ fffffffdfe800000 fffffffdff7fffff 16MB PCI I/O space
+ fffffffdff800000 fffffffdffffffff 8MB [guard region]
+ fffffffe00000000 ffffffffefffffff 4GB vmemmap
+ ffffffff00000000 ffffffffffffffff 4GB [guard region]
+
+
AArch64 Linux memory layout with 4KB pages + 4 levels (48-bit)::

Start End Size Use
--
2.33.0