This is a note to let you know that I've just added the patch titled
Documentation: riscv: Document the sv57 VM layout
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
documentation-riscv-document-the-sv57-vm-layout.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a6c803a703cd8d472810dae0ba1f2b2868a94354
Author: Björn Töpel <bjorn@xxxxxxxxxxxx>
Date: Fri Nov 18 18:15:56 2022 +0100
Documentation: riscv: Document the sv57 VM layout
[ Upstream commit dd3553793a759e4f7f21c1aaffd5cb2de7a0068d ]
RISC-V has been supporting the "sv57" address translation mode for a
while, but is has not been added to the VM layout documentation. Let
us fix that.
Signed-off-by: Björn Töpel <bjorn@xxxxxxxxxxxx>
Reviewed-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221118171556.1612190-1-bjorn@xxxxxxxxxx
Signed-off-by: Jonathan Corbet <corbet@xxxxxxx>
Stable-dep-of: ef69d2559fe9 ("riscv: Move early dtb mapping into the fixmap region")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/Documentation/riscv/vm-layout.rst b/Documentation/riscv/vm-layout.rst
index 5b36e45fef60b..3be44e74ec5d6 100644
--- a/Documentation/riscv/vm-layout.rst
+++ b/Documentation/riscv/vm-layout.rst
@@ -97,3 +97,39 @@ RISC-V Linux Kernel SV48
ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | modules, BPF
ffffffff80000000 | -2 GB | ffffffffffffffff | 2 GB | kernel
__________________|____________|__________________|_________|____________________________________________________________
+
+
+RISC-V Linux Kernel SV57
+------------------------
+
+::
+
+ ========================================================================================================================
+ Start addr | Offset | End addr | Size | VM area description
+ ========================================================================================================================
+ | | | |
+ 0000000000000000 | 0 | 00ffffffffffffff | 64 PB | user-space virtual memory, different per mm
+ __________________|____________|__________________|_________|___________________________________________________________
+ | | | |
+ 0100000000000000 | +64 PB | feffffffffffffff | ~16K PB | ... huge, almost 64 bits wide hole of non-canonical
+ | | | | virtual memory addresses up to the -64 PB
+ | | | | starting offset of kernel mappings.
+ __________________|____________|__________________|_________|___________________________________________________________
+ |
+ | Kernel-space virtual memory, shared between all processes:
+ ____________________________________________________________|___________________________________________________________
+ | | | |
+ ff1bfffffee00000 | -57 PB | ff1bfffffeffffff | 2 MB | fixmap
+ ff1bffffff000000 | -57 PB | ff1bffffffffffff | 16 MB | PCI io
+ ff1c000000000000 | -57 PB | ff1fffffffffffff | 1 PB | vmemmap
+ ff20000000000000 | -56 PB | ff5fffffffffffff | 16 PB | vmalloc/ioremap space
+ ff60000000000000 | -40 PB | ffdeffffffffffff | 32 PB | direct mapping of all physical memory
+ ffdf000000000000 | -8 PB | fffffffeffffffff | 8 PB | kasan
+ __________________|____________|__________________|_________|____________________________________________________________
+ |
+ | Identical layout to the 39-bit one from here on:
+ ____________________________________________________________|____________________________________________________________
+ | | | |
+ ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | modules, BPF
+ ffffffff80000000 | -2 GB | ffffffffffffffff | 2 GB | kernel
+ __________________|____________|__________________|_________|____________________________________________________________
