diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2024-02-14 13:29:18 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2024-02-16 12:42:39 +0000 |
| commit | 2b6c8f96cc47eb1b41f7ebf28dfc2459c39f7fa9 (patch) | |
| tree | 2fa1b9722c08b73378422a64df19f3e0e244c388 /arch/arm64/kernel | |
| parent | a6bbf5d4d9d13509fd068de664238c16934962c6 (diff) | |
arm64: mm: add LPA2 and 5 level paging support to G-to-nG conversion
Add support for 5 level paging in the G-to-nG routine that creates its
own temporary page tables to traverse the swapper page tables. Also add
support for running the 5 level configuration with the top level folded
at runtime, to support CPUs that do not implement the LPA2 extension.
While at it, wire up the level skipping logic so it will also trigger on
4 level configurations with LPA2 enabled at build time but not active at
runtime, as we'll fall back to 3 level paging in that case.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240214122845.2033971-77-ardb+git@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index ed9670d8360c..bc5e4e569864 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1765,6 +1765,9 @@ static int __init __kpti_install_ng_mappings(void *__unused) pgd_t *kpti_ng_temp_pgd; u64 alloc = 0; + if (levels == 5 && !pgtable_l5_enabled()) + levels = 4; + remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings); if (!cpu) { @@ -1778,9 +1781,9 @@ static int __init __kpti_install_ng_mappings(void *__unused) // // The physical pages are laid out as follows: // - // +--------+-/-------+-/------ +-\\--------+ - // : PTE[] : | PMD[] : | PUD[] : || PGD[] : - // +--------+-\-------+-\------ +-//--------+ + // +--------+-/-------+-/------ +-/------ +-\\\--------+ + // : PTE[] : | PMD[] : | PUD[] : | P4D[] : ||| PGD[] : + // +--------+-\-------+-\------ +-\------ +-///--------+ // ^ // The first page is mapped into this hierarchy at a PMD_SHIFT // aligned virtual address, so that we can manipulate the PTE |