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authorAlexandre Ghiti <alexandre.ghiti@canonical.com>2021-12-06 11:46:55 +0100
committerPalmer Dabbelt <palmer@rivosinc.com>2022-06-02 05:38:34 +0200
commit9d19f2b5256ef6cdd4947b48fab4032d0060e916 (patch)
treee9367ff01cbc4a6c422d1c59448e6dc6a292bc42 /Documentation
parentRISC-V: Only default to spinwait on SBI-0.1 and M-mode (diff)
downloadlinux-9d19f2b5256ef6cdd4947b48fab4032d0060e916.tar.xz
linux-9d19f2b5256ef6cdd4947b48fab4032d0060e916.zip
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 <alexandre.ghiti@canonical.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/riscv/vm-layout.rst36
1 files changed, 36 insertions, 0 deletions
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
+ __________________|____________|__________________|_________|____________________________________________________________