diff options
| author | Alexandre Ghiti <alexandre.ghiti@canonical.com> | 2021-12-06 11:46:51 +0100 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-01-19 17:54:09 -0800 |
| commit | e8a62cc26ddf53a3c6ba2a8d33036cf7b84f3923 (patch) | |
| tree | 15b9020880a651c756268a4560b8c6c720fc1031 /arch/riscv/Kconfig | |
| parent | 60639f74c2f4fcc3ffa2ac0b120eaa874ccc713f (diff) | |
riscv: Implement sv48 support
By adding a new 4th level of page table, give the possibility to 64bit
kernel to address 2^48 bytes of virtual address: in practice, that offers
128TB of virtual address space to userspace and allows up to 64TB of
physical memory.
If the underlying hardware does not support sv48, we will automatically
fallback to a standard 3-level page table by folding the new PUD level into
PGDIR level. In order to detect HW capabilities at runtime, we
use SATP feature that ignores writes with an unsupported mode.
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/Kconfig')
| -rw-r--r-- | arch/riscv/Kconfig | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 7945bacb1d0e..c4289d755dd4 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -150,7 +150,7 @@ config PAGE_OFFSET hex default 0xC0000000 if 32BIT default 0x80000000 if 64BIT && !MMU - default 0xffffffd800000000 if 64BIT + default 0xffffaf8000000000 if 64BIT config KASAN_SHADOW_OFFSET hex @@ -201,7 +201,7 @@ config FIX_EARLYCON_MEM config PGTABLE_LEVELS int - default 3 if 64BIT + default 4 if 64BIT default 2 config LOCKDEP_SUPPORT |