path: root/arch/arm64/include/asm/pgtable.h
diff options
authorArd Biesheuvel <ard.biesheuvel@linaro.org>2017-03-09 21:52:09 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2017-03-23 14:09:23 +0000
commitd27cfa1fc823d35a6cf45ba51f5623db8a14a9b9 (patch)
tree789957b38e836bdb084b2588b6d5223688ad3119 /arch/arm64/include/asm/pgtable.h
parentarm64/mm: remove pointless map/unmap sequences when creating page tables (diff)
arm64: mm: set the contiguous bit for kernel mappings where appropriate
This is the third attempt at enabling the use of contiguous hints for kernel mappings. The most recent attempt 0bfc445dec9d was reverted after it turned out that updating permission attributes on live contiguous ranges may result in TLB conflicts. So this time, the contiguous hint is not set for .rodata or for the linear alias of .text/.rodata, both of which are mapped read-write initially, and remapped read-only at a later stage. (Note that the latter region could also be unmapped and remapped again with updated permission attributes, given that the region, while live, is only mapped for the convenience of the hibernation code, but that also means the TLB footprint is negligible anyway, so why bother) This enables the following contiguous range sizes for the virtual mapping of the kernel image, and for the linear mapping: granule size | cont PTE | cont PMD | -------------+------------+------------+ 4 KB | 64 KB | 32 MB | 16 KB | 2 MB | 1 GB* | 64 KB | 2 MB | 16 GB* | * Only when built for 3 or more levels of translation. This is due to the fact that a 2 level configuration only consists of PGDs and PTEs, and the added complexity of dealing with folded PMDs is not justified considering that 16 GB contiguous ranges are likely to be ignored by the hardware (and 16k/2 levels is a niche configuration) Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to '')
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 0eef6064bf3b..c213fdbd056c 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -74,6 +74,16 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
#define pte_user_exec(pte) (!(pte_val(pte) & PTE_UXN))
#define pte_cont(pte) (!!(pte_val(pte) & PTE_CONT))
+#define pte_cont_addr_end(addr, end) \
+({ unsigned long __boundary = ((addr) + CONT_PTE_SIZE) & CONT_PTE_MASK; \
+ (__boundary - 1 < (end) - 1) ? __boundary : (end); \
+#define pmd_cont_addr_end(addr, end) \
+({ unsigned long __boundary = ((addr) + CONT_PMD_SIZE) & CONT_PMD_MASK; \
+ (__boundary - 1 < (end) - 1) ? __boundary : (end); \
#define pte_hw_dirty(pte) (pte_write(pte) && !(pte_val(pte) & PTE_RDONLY))