Am Mittwoch, 29. September 2021, 16:51:03 CET schrieb Alexandre Ghiti: > 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. > > Tested on: > - qemu rv64 sv39: OK > - qemu rv64 sv48: OK > - qemu rv64 sv39 + kasan: OK > - qemu rv64 sv48 + kasan: OK > - qemu rv32: OK > - Unmatched: OK On a beagleV (which supports only sv39) I've tested both the limit via the mmu-type in the devicetree and also that the fallback works when I disable the mmu-type in the dt, so Tested-by: Heiko Stuebner <heiko@xxxxxxxxx> > > > Changes in v2: > - Rebase onto for-next > - Fix KASAN > - Fix stack canary > - Get completely rid of MAXPHYSMEM configs > - Add documentation > > Alexandre Ghiti (10): > riscv: Allow to dynamically define VA_BITS > riscv: Get rid of MAXPHYSMEM configs > asm-generic: Prepare for riscv use of pud_alloc_one and pud_free > riscv: Implement sv48 support > riscv: Use pgtable_l4_enabled to output mmu_type in cpuinfo > riscv: Explicit comment about user virtual address space size > riscv: Improve virtual kernel memory layout dump > Documentation: riscv: Add sv48 description to VM layout > riscv: Initialize thread pointer before calling C functions > riscv: Allow user to downgrade to sv39 when hw supports sv48 > > Documentation/riscv/vm-layout.rst | 36 ++ > arch/riscv/Kconfig | 35 +- > arch/riscv/configs/nommu_k210_defconfig | 1 - > .../riscv/configs/nommu_k210_sdcard_defconfig | 1 - > arch/riscv/configs/nommu_virt_defconfig | 1 - > arch/riscv/include/asm/csr.h | 3 +- > arch/riscv/include/asm/fixmap.h | 1 + > arch/riscv/include/asm/kasan.h | 2 +- > arch/riscv/include/asm/page.h | 10 + > arch/riscv/include/asm/pgalloc.h | 40 +++ > arch/riscv/include/asm/pgtable-64.h | 108 +++++- > arch/riscv/include/asm/pgtable.h | 30 +- > arch/riscv/include/asm/sparsemem.h | 6 +- > arch/riscv/kernel/cpu.c | 23 +- > arch/riscv/kernel/head.S | 4 +- > arch/riscv/mm/context.c | 4 +- > arch/riscv/mm/init.c | 323 +++++++++++++++--- > arch/riscv/mm/kasan_init.c | 91 +++-- > drivers/firmware/efi/libstub/efi-stub.c | 2 + > include/asm-generic/pgalloc.h | 24 +- > include/linux/sizes.h | 1 + > 21 files changed, 615 insertions(+), 131 deletions(-) > >
