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| author | Palmer Dabbelt <palmer@rivosinc.com> | 2022-01-20 06:23:41 +0300 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-01-20 06:37:44 +0300 |
| commit | 0c34e79e52bb13881c08f1a2c2390b7b88ff10c7 (patch) | |
| tree | e8caa54b625f2364cee088c37c088de1d28a32b8 /arch/riscv/Kconfig | |
| parent | fc839c6d33c8828514f595822f457e51328507e5 (diff) | |
| parent | c774de22c430733487f70d755067d9ea55dbe6de (diff) | |
| download | linux-0c34e79e52bb13881c08f1a2c2390b7b88ff10c7.tar.xz | |
RISC-V: Introduce sv48 support without relocatable kernel
This patchset allows to have a single kernel for sv39 and sv48 without
being relocatable.
The idea comes from Arnd Bergmann who suggested to do the same as x86,
that is mapping the kernel to the end of the address space, which allows
the kernel to be linked at the same address for both sv39 and sv48 and
then does not require to be relocated at runtime.
This implements sv48 support at runtime. The kernel will try to boot
with 4-level page table and will fallback to 3-level if the HW does not
support it. Folding the 4th level into a 3-level page table has almost
no cost at runtime.
Note that kasan region had to be moved to the end of the address space
since its location must be known at compile-time and then be valid for
both sv39 and sv48 (and sv57 that is coming).
* riscv-sv48-v3:
riscv: Explicit comment about user virtual address space size
riscv: Use pgtable_l4_enabled to output mmu_type in cpuinfo
riscv: Implement sv48 support
asm-generic: Prepare for riscv use of pud_alloc_one and pud_free
riscv: Allow to dynamically define VA_BITS
riscv: Introduce functions to switch pt_ops
riscv: Split early kasan mapping to prepare sv48 introduction
riscv: Move KASAN mapping next to the kernel mapping
riscv: Get rid of MAXPHYSMEM configs
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/Kconfig')
| -rw-r--r-- | arch/riscv/Kconfig | 37 |
1 files changed, 4 insertions, 33 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 4602cfe92a20..38205f25c0d7 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -147,27 +147,16 @@ config MMU Select if you want MMU-based virtualised addressing space support by paged memory management. If unsure, say 'Y'. -config VA_BITS - int - default 32 if 32BIT - default 39 if 64BIT - -config PA_BITS - int - default 34 if 32BIT - default 56 if 64BIT - config PAGE_OFFSET hex - default 0xC0000000 if 32BIT && MAXPHYSMEM_1GB + default 0xC0000000 if 32BIT default 0x80000000 if 64BIT && !MMU - default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB - default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB + default 0xffffaf8000000000 if 64BIT config KASAN_SHADOW_OFFSET hex depends on KASAN_GENERIC - default 0xdfffffc800000000 if 64BIT + default 0xdfffffff00000000 if 64BIT default 0xffffffff if 32BIT config ARCH_FLATMEM_ENABLE @@ -213,7 +202,7 @@ config FIX_EARLYCON_MEM config PGTABLE_LEVELS int - default 3 if 64BIT + default 4 if 64BIT default 2 config LOCKDEP_SUPPORT @@ -271,24 +260,6 @@ config MODULE_SECTIONS bool select HAVE_MOD_ARCH_SPECIFIC -choice - prompt "Maximum Physical Memory" - default MAXPHYSMEM_1GB if 32BIT - default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW - default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY - - config MAXPHYSMEM_1GB - depends on 32BIT - bool "1GiB" - config MAXPHYSMEM_2GB - depends on 64BIT - bool "2GiB" - config MAXPHYSMEM_128GB - depends on 64BIT && CMODEL_MEDANY - bool "128GiB" -endchoice - - config SMP bool "Symmetric Multi-Processing" help |