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Merge branch 'for-next/docs' into for-next/core

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* for-next/docs:
  Documentation: arm64: Remove stale and redundant virtual memory diagrams
  docs: arm64: Document EL3 requirements for FEAT_PMUv3
  docs: arm64: Document EL3 requirements for cpu debug architecture
This commit is contained in:
Will Deacon 2025-01-17 13:52:23 +00:00
commit e190227be4
2 changed files with 12 additions and 65 deletions
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12
Documentation/arch/arm64/booting.rst
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@ -449,6 +449,18 @@ Before jumping into the kernel, the following conditions must be met:
- HFGWTR_EL2.nGCS_EL0 (bit 52) must be initialised to 0b1.
- For CPUs with debug architecture i.e FEAT_Debugv8pN (all versions):
- If EL3 is present:
- MDCR_EL3.TDA (bit 9) must be initialized to 0b0
- For CPUs with FEAT_PMUv3:
- If EL3 is present:
- MDCR_EL3.TPM (bit 6) must be initialized to 0b0
The requirements described above for CPU mode, caches, MMUs, architected
timers, coherency and system registers apply to all CPUs. All CPUs must
enter the kernel in the same exception level. Where the values documented

65
Documentation/arch/arm64/memory.rst
View File

@ -23,71 +23,6 @@ swapper_pg_dir contains only kernel (global) mappings while the user pgd
contains only user (non-global) mappings. The swapper_pg_dir address is
written to TTBR1 and never written to TTBR0.
AArch64 Linux memory layout with 4KB pages + 4 levels (48-bit)::
Start End Size Use
-----------------------------------------------------------------------
0000000000000000 0000ffffffffffff 256TB user
ffff000000000000 ffff7fffffffffff 128TB kernel logical memory map
[ffff600000000000 ffff7fffffffffff] 32TB [kasan shadow region]
ffff800000000000 ffff80007fffffff 2GB modules
ffff800080000000 fffffbffefffffff 124TB vmalloc
fffffbfff0000000 fffffbfffdffffff 224MB fixed mappings (top down)
fffffbfffe000000 fffffbfffe7fffff 8MB [guard region]
fffffbfffe800000 fffffbffff7fffff 16MB PCI I/O space
fffffbffff800000 fffffbffffffffff 8MB [guard region]
fffffc0000000000 fffffdffffffffff 2TB vmemmap
fffffe0000000000 ffffffffffffffff 2TB [guard region]
AArch64 Linux memory layout with 64KB pages + 3 levels (52-bit with HW support)::
Start End Size Use
-----------------------------------------------------------------------
0000000000000000 000fffffffffffff 4PB user
fff0000000000000 ffff7fffffffffff ~4PB kernel logical memory map
[fffd800000000000 ffff7fffffffffff] 512TB [kasan shadow region]
ffff800000000000 ffff80007fffffff 2GB modules
ffff800080000000 fffffbffefffffff 124TB vmalloc
fffffbfff0000000 fffffbfffdffffff 224MB fixed mappings (top down)
fffffbfffe000000 fffffbfffe7fffff 8MB [guard region]
fffffbfffe800000 fffffbffff7fffff 16MB PCI I/O space
fffffbffff800000 fffffbffffffffff 8MB [guard region]
fffffc0000000000 ffffffdfffffffff ~4TB vmemmap
ffffffe000000000 ffffffffffffffff 128GB [guard region]
Translation table lookup with 4KB pages::
+--------+--------+--------+--------+--------+--------+--------+--------+
|63 56|55 48|47 40|39 32|31 24|23 16|15 8|7 0|
+--------+--------+--------+--------+--------+--------+--------+--------+
| | | | | |
| | | | | v
| | | | | [11:0] in-page offset
| | | | +-> [20:12] L3 index
| | | +-----------> [29:21] L2 index
| | +---------------------> [38:30] L1 index
| +-------------------------------> [47:39] L0 index
+----------------------------------------> [55] TTBR0/1
Translation table lookup with 64KB pages::
+--------+--------+--------+--------+--------+--------+--------+--------+
|63 56|55 48|47 40|39 32|31 24|23 16|15 8|7 0|
+--------+--------+--------+--------+--------+--------+--------+--------+
| | | | |
| | | | v
| | | | [15:0] in-page offset
| | | +----------> [28:16] L3 index
| | +--------------------------> [41:29] L2 index
| +-------------------------------> [47:42] L1 index (48-bit)
| [51:42] L1 index (52-bit)
+----------------------------------------> [55] TTBR0/1
When using KVM without the Virtualization Host Extensions, the
hypervisor maps kernel pages in EL2 at a fixed (and potentially
random) offset from the linear mapping. See the kern_hyp_va macro and