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Subject[PATCH v7 0/4] riscv: Use PUD/P4D/PGD pages for the linear mapping
Date
This patchset intends to improve tlb utilization by using hugepages for
the linear mapping.

As reported by Anup in v6, when STRICT_KERNEL_RWX is enabled, we must
take care of isolating the kernel text and rodata so that they are not
mapped with a PUD mapping which would then assign wrong permissions to
the whole region: it is achieved by introducing a new memblock API.

Another patch makes use of this new API in arm64 which used some sort of
hack to solve this issue: it was built/boot tested successfully.

base-commit-tag: v6.3-rc1

v7:
- Fix Anup bug report by introducing memblock_isolate_memory which
allows us to split the memblock mappings and then avoid to map the
the PUD which contains the kernel as read only
- Add a patch to arm64 to use this newly introduced API

v6:
- quiet LLVM warning by casting phys_ram_base into an unsigned long

v5:
- Fix nommu builds by getting rid of riscv_pfn_base in patch 1, thanks
Conor
- Add RB from Andrew

v4:
- Rebase on top of v6.2-rc3, as noted by Conor
- Add Acked-by Rob

v3:
- Change the comment about initrd_start VA conversion so that it fits
ARM64 and RISCV64 (and others in the future if needed), as suggested
by Rob

v2:
- Add a comment on why RISCV64 does not need to set initrd_start/end that
early in the boot process, as asked by Rob

Alexandre Ghiti (4):
riscv: Get rid of riscv_pfn_base variable
mm: Introduce memblock_isolate_memory
arm64: Make use of memblock_isolate_memory for the linear mapping
riscv: Use PUD/P4D/PGD pages for the linear mapping

arch/arm64/mm/mmu.c | 4 ++--
arch/riscv/include/asm/page.h | 19 +++++++++++++++--
arch/riscv/mm/init.c | 39 ++++++++++++++++++++++++++---------
arch/riscv/mm/physaddr.c | 16 ++++++++++++++
drivers/of/fdt.c | 11 +++++-----
include/linux/memblock.h | 1 +
mm/memblock.c | 22 +++++++++++++++++++-
7 files changed, 92 insertions(+), 20 deletions(-)

--
2.37.2

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