From 9d19f2b5256ef6cdd4947b48fab4032d0060e916 Mon Sep 17 00:00:00 2001 From: Alexandre Ghiti Date: Mon, 6 Dec 2021 11:46:55 +0100 Subject: Documentation: riscv: Add sv48 description to VM layout sv48 was just introduced, so add its virtual memory layout to the documentation. Signed-off-by: Alexandre Ghiti Signed-off-by: Palmer Dabbelt --- Documentation/riscv/vm-layout.rst | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'Documentation/riscv') diff --git a/Documentation/riscv/vm-layout.rst b/Documentation/riscv/vm-layout.rst index 1bd687b97104..5b36e45fef60 100644 --- a/Documentation/riscv/vm-layout.rst +++ b/Documentation/riscv/vm-layout.rst @@ -61,3 +61,39 @@ RISC-V Linux Kernel SV39 ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | modules, BPF ffffffff80000000 | -2 GB | ffffffffffffffff | 2 GB | kernel __________________|____________|__________________|_________|____________________________________________________________ + + +RISC-V Linux Kernel SV48 +------------------------ + +:: + + ======================================================================================================================== + Start addr | Offset | End addr | Size | VM area description + ======================================================================================================================== + | | | | + 0000000000000000 | 0 | 00007fffffffffff | 128 TB | user-space virtual memory, different per mm + __________________|____________|__________________|_________|___________________________________________________________ + | | | | + 0000800000000000 | +128 TB | ffff7fffffffffff | ~16M TB | ... huge, almost 64 bits wide hole of non-canonical + | | | | virtual memory addresses up to the -128 TB + | | | | starting offset of kernel mappings. + __________________|____________|__________________|_________|___________________________________________________________ + | + | Kernel-space virtual memory, shared between all processes: + ____________________________________________________________|___________________________________________________________ + | | | | + ffff8d7ffee00000 | -114.5 TB | ffff8d7ffeffffff | 2 MB | fixmap + ffff8d7fff000000 | -114.5 TB | ffff8d7fffffffff | 16 MB | PCI io + ffff8d8000000000 | -114.5 TB | ffff8f7fffffffff | 2 TB | vmemmap + ffff8f8000000000 | -112.5 TB | ffffaf7fffffffff | 32 TB | vmalloc/ioremap space + ffffaf8000000000 | -80.5 TB | ffffef7fffffffff | 64 TB | direct mapping of all physical memory + ffffef8000000000 | -16.5 TB | fffffffeffffffff | 16.5 TB | 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 + __________________|____________|__________________|_________|____________________________________________________________ -- cgit v1.2.3