diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2023-12-13 09:40:27 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2024-02-09 10:56:11 +0000 |
| commit | b730b0f2b1fcfbdaed816152cc71993fd708aa11 (patch) | |
| tree | 071b31e37f70c215f569ba94d0aa960f4758ce8a /arch/arm64/mm/fixmap.c | |
| parent | 031e011d8b22346a6513c7879cbecd7105b4c11d (diff) | |
arm64: mm: Move fixmap region above vmemmap region
Move the fixmap region above the vmemmap region, so that the start of
the vmemmap delineates the end of the region available for vmalloc and
vmap allocations and the randomized placement of the kernel and modules.
In a subsequent patch, we will take advantage of this to reclaim most of
the vmemmap area when running a 52-bit VA capable build with 52-bit
virtual addressing disabled at runtime.
Note that the existing guard region of 256 MiB covers the fixmap and PCI
I/O regions as well, so we can reduce it 8 MiB, which is what we use in
other places too.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20231213084024.2367360-11-ardb@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Diffstat (limited to 'arch/arm64/mm/fixmap.c')
| -rw-r--r-- | arch/arm64/mm/fixmap.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm64/mm/fixmap.c b/arch/arm64/mm/fixmap.c index c0a3301203bd..6fc17b2e1714 100644 --- a/arch/arm64/mm/fixmap.c +++ b/arch/arm64/mm/fixmap.c @@ -16,6 +16,9 @@ #include <asm/pgalloc.h> #include <asm/tlbflush.h> +/* ensure that the fixmap region does not grow down into the PCI I/O region */ +static_assert(FIXADDR_TOT_START > PCI_IO_END); + #define NR_BM_PTE_TABLES \ SPAN_NR_ENTRIES(FIXADDR_TOT_START, FIXADDR_TOP, PMD_SHIFT) #define NR_BM_PMD_TABLES \ |