[v4,0/2] Two-stagged initial page table setup

Message

Anup Patel May 2, 2019, 5:02 a.m. UTC

This patchset implements two-stagged initial page table setup using fixmap
to avoid mapping non-existent RAM and also reduce high_memory consumed by
initial page tables.

The patchset is based on Linux-5.1-rc7 and tested on SiFive Unleashed board
and QEMU virt machine.

These patches can be found in riscv_setup_vm_v4 branch of
https//github.com/avpatel/linux.git

Changes since v3:
- Changed patch series subject.
- Dropped PATCH1 because it's already merged
- Dropped PATCH3 because trampoline page table handles a corner case
  for 32bit systems where load address range overlaps kernel virtual
  address range
- Revamped PATCH for 4K aligned booting into two-stagged initial page
  table setup

Changes since v2:
- Dropped PATCH2 because we have separate fix for Linux-5.1-rcX
- Moved PATCH5 to PATCH2
- Moved PATCH4 to PATCH3
- The "Booting kernel from any 4KB aligned address" is now PATCH4

Changes since v1:
- Add kconfig option BOOT_PAGE_ALIGNED to enable 4KB aligned booting
- Improved initial page table setup code to select best/biggest
  possible mapping size based on load address alignment
- Added PATCH4 to remove redundant trampoline page table
- Added PATCH5 to fix memory reservation in setup_bootmem()

Anup Patel (2):
  RISC-V: Fix memory reservation in setup_bootmem()
  RISC-V: Setup initial page tables in two stages

 arch/riscv/include/asm/fixmap.h     |   5 +
 arch/riscv/include/asm/pgtable-64.h |   5 +
 arch/riscv/include/asm/pgtable.h    |   7 +
 arch/riscv/kernel/head.S            |  17 +-
 arch/riscv/kernel/setup.c           |   4 +-
 arch/riscv/mm/init.c                | 327 ++++++++++++++++++++++------
 6 files changed, 289 insertions(+), 76 deletions(-)

--
2.17.1

Comments

Anup Patel May 20, 2019, 8:44 a.m. UTC | #1

On Thu, May 2, 2019 at 10:32 AM Anup Patel <[e-mail]> wrote:
>
> This patchset implements two-stagged initial page table setup using fixmap
> to avoid mapping non-existent RAM and also reduce high_memory consumed by
> initial page tables.
>
> The patchset is based on Linux-5.1-rc7 and tested on SiFive Unleashed board
> and QEMU virt machine.
>
> These patches can be found in riscv_setup_vm_v4 branch of
> https//github.com/avpatel/linux.git
>
> Changes since v3:
> - Changed patch series subject.
> - Dropped PATCH1 because it's already merged
> - Dropped PATCH3 because trampoline page table handles a corner case
>   for 32bit systems where load address range overlaps kernel virtual
>   address range
> - Revamped PATCH for 4K aligned booting into two-stagged initial page
>   table setup
>
> Changes since v2:
> - Dropped PATCH2 because we have separate fix for Linux-5.1-rcX
> - Moved PATCH5 to PATCH2
> - Moved PATCH4 to PATCH3
> - The "Booting kernel from any 4KB aligned address" is now PATCH4
>
> Changes since v1:
> - Add kconfig option BOOT_PAGE_ALIGNED to enable 4KB aligned booting
> - Improved initial page table setup code to select best/biggest
>   possible mapping size based on load address alignment
> - Added PATCH4 to remove redundant trampoline page table
> - Added PATCH5 to fix memory reservation in setup_bootmem()
>
> Anup Patel (2):
>   RISC-V: Fix memory reservation in setup_bootmem()
>   RISC-V: Setup initial page tables in two stages
>
>  arch/riscv/include/asm/fixmap.h     |   5 +
>  arch/riscv/include/asm/pgtable-64.h |   5 +
>  arch/riscv/include/asm/pgtable.h    |   7 +
>  arch/riscv/kernel/head.S            |  17 +-
>  arch/riscv/kernel/setup.c           |   4 +-
>  arch/riscv/mm/init.c                | 327 ++++++++++++++++++++++------
>  6 files changed, 289 insertions(+), 76 deletions(-)
>
> --
> 2.17.1

Hi All,

Any comments on this patchset?

Regards,
Anup