leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Documentation: riscv: Add sv48 description to VM layout

Browse Source 
sv48 was just introduced, so add its virtual memory layout to the
documentation.

Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Alexandre Ghiti 2021-12-06 11:46:55 +01:00 committed by Palmer Dabbelt
parent 77d707a310
commit 9d19f2b525
No known key found for this signature in database
GPG Key ID: 2E1319F35FBB1889
1 changed files with 36 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
Documentation/riscv/vm-layout.rst
View File

@ -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
__________________|____________|__________________|_________|____________________________________________________________