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Diffstat (limited to 'Documentation/arch/riscv/vm-layout.rst')
| -rw-r--r-- | Documentation/arch/riscv/vm-layout.rst | 16 |
1 files changed, 0 insertions, 16 deletions
diff --git a/Documentation/arch/riscv/vm-layout.rst b/Documentation/arch/riscv/vm-layout.rst index 077b968dcc81..eabec99b5852 100644 --- a/Documentation/arch/riscv/vm-layout.rst +++ b/Documentation/arch/riscv/vm-layout.rst @@ -134,19 +134,3 @@ RISC-V Linux Kernel SV57 ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | modules, BPF ffffffff80000000 | -2 GB | ffffffffffffffff | 2 GB | kernel __________________|____________|__________________|_________|____________________________________________________________ - - -Userspace VAs --------------------- -To maintain compatibility with software that relies on the VA space with a -maximum of 48 bits the kernel will, by default, return virtual addresses to -userspace from a 48-bit range (sv48). This default behavior is achieved by -passing 0 into the hint address parameter of mmap. On CPUs with an address space -smaller than sv48, the CPU maximum supported address space will be the default. - -Software can "opt-in" to receiving VAs from another VA space by providing -a hint address to mmap. When a hint address is passed to mmap, the returned -address will never use more bits than the hint address. For example, if a hint -address of `1 << 40` is passed to mmap, a valid returned address will never use -bits 41 through 63. If no mappable addresses are available in that range, mmap -will return `MAP_FAILED`. |