]> git.baikalelectronics.ru Git - kernel.git/commit
arm64: Extend early page table code to allow for larger kernels
authorSteve Capper <steve.capper@arm.com>
Thu, 11 Jan 2018 10:11:59 +0000 (10:11 +0000)
committerCatalin Marinas <catalin.marinas@arm.com>
Sun, 14 Jan 2018 18:49:52 +0000 (18:49 +0000)
commit6d059b4a2df5a424f2c2194d5bd651750fb50402
tree343ee02500bf2154425f058c51e7af107a10635f
parenteee5b332f86abcbec12c3f9adfe906cfa67899c4
arm64: Extend early page table code to allow for larger kernels

Currently the early assembler page table code assumes that precisely
1xpgd, 1xpud, 1xpmd are sufficient to represent the early kernel text
mappings.

Unfortunately this is rarely the case when running with a 16KB granule,
and we also run into limits with 4KB granule when building much larger
kernels.

This patch re-writes the early page table logic to compute indices of
mappings for each level of page table, and if multiple indices are
required, the next-level page table is scaled up accordingly.

Also the required size of the swapper_pg_dir is computed at link time
to cover the mapping [KIMAGE_ADDR + VOFFSET, _end]. When KASLR is
enabled, an extra page is set aside for each level that may require extra
entries at runtime.

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arch/arm64/include/asm/kernel-pgtable.h
arch/arm64/include/asm/pgtable.h
arch/arm64/kernel/head.S
arch/arm64/kernel/vmlinux.lds.S
arch/arm64/mm/mmu.c