Searched hist:"0 bfc445d" (Results 1 – 1 of 1) sorted by relevance
| /openbmc/linux/arch/arm64/mm/ |
| H A D | mmu.c | 0bfc445d Fri Oct 21 06:22:58 CDT 2016 Ard Biesheuvel <ard.biesheuvel@linaro.org> arm64: mm: set the contiguous bit for kernel mappings where appropriate
Now that we no longer allow live kernel PMDs to be split, it is safe to
start using the contiguous bit for kernel mappings. So set the contiguous
bit in the kernel page mappings for regions whose size and alignment are
suitable for this.
This enables the following contiguous range sizes for the virtual mapping
of the kernel image, and for the linear mapping:
granule size | cont PTE | cont PMD |
-------------+------------+------------+
4 KB | 64 KB | 32 MB |
16 KB | 2 MB | 1 GB* |
64 KB | 2 MB | 16 GB* |
* Only when built for 3 or more levels of translation. This is due to the
fact that a 2 level configuration only consists of PGDs and PTEs, and the
added complexity of dealing with folded PMDs is not justified considering
that 16 GB contiguous ranges are likely to be ignored by the hardware (and
16k/2 levels is a niche configuration)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
0bfc445d Fri Oct 21 06:22:58 CDT 2016 Ard Biesheuvel <ard.biesheuvel@linaro.org> arm64: mm: set the contiguous bit for kernel mappings where appropriate
Now that we no longer allow live kernel PMDs to be split, it is safe to
start using the contiguous bit for kernel mappings. So set the contiguous
bit in the kernel page mappings for regions whose size and alignment are
suitable for this.
This enables the following contiguous range sizes for the virtual mapping
of the kernel image, and for the linear mapping:
granule size | cont PTE | cont PMD |
-------------+------------+------------+
4 KB | 64 KB | 32 MB |
16 KB | 2 MB | 1 GB* |
64 KB | 2 MB | 16 GB* |
* Only when built for 3 or more levels of translation. This is due to the
fact that a 2 level configuration only consists of PGDs and PTEs, and the
added complexity of dealing with folded PMDs is not justified considering
that 16 GB contiguous ranges are likely to be ignored by the hardware (and
16k/2 levels is a niche configuration)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
|