xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

arm64: mm: Introduce MAX_USER_VA_BITS definition

Browse Source 
With the introduction of 52-bit virtual addressing for userspace, we are
now in a position where the virtual addressing capability of userspace
may exceed that of the kernel. Consequently, the VA_BITS definition
cannot be used blindly, since it reflects only the size of kernel
virtual addresses.

This patch introduces MAX_USER_VA_BITS which is either VA_BITS or 52
depending on whether 52-bit virtual addressing has been configured at
build time, removing a few places where the 52 is open-coded based on
explicit CONFIG_ guards.

Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Will Deacon
2018-12-12 11:51:40 +00:00
parent 4d08d20f1c
commit 9b31cf493f
3 changed files with 8 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
arch/arm64/include/asm/pgtable-hwdef.h
View File

@@ -80,11 +80,7 @@
#define PGDIR_SHIFT ARM64_HW_PGTABLE_LEVEL_SHIFT(4 - CONFIG_PGTABLE_LEVELS)
#define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
#ifdef CONFIG_ARM64_USER_VA_BITS_52
#define PTRS_PER_PGD (1 << (52 - PGDIR_SHIFT))
#else
#define PTRS_PER_PGD (1 << (VA_BITS - PGDIR_SHIFT))
#endif
#define PTRS_PER_PGD (1 << (MAX_USER_VA_BITS - PGDIR_SHIFT))
/*
* Section address mask and size definitions.