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| author | Ard Biesheuvel <ardb@kernel.org> | 2020-10-08 17:36:01 +0200 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-11-09 17:15:37 +0000 |
| commit | 8c96400d6a39be763130a5c493647c57726f7013 (patch) | |
| tree | 0794db8f11e674731069015b34a5c593f8a77ac7 /arch/arm64/mm | |
| parent | f4693c2716b35d0846fd45a4ad7db78bfb25efc8 (diff) | |
| download | linux-8c96400d6a39be763130a5c493647c57726f7013.tar.gz | |
arm64: mm: make vmemmap region a projection of the linear region
Now that we have reverted the introduction of the vmemmap struct page
pointer and the separate physvirt_offset, we can simplify things further,
and place the vmemmap region in the VA space in such a way that virtual
to page translations and vice versa can be implemented using a single
arithmetic shift.
One happy coincidence resulting from this is that the 48-bit/4k and
52-bit/64k configurations (which are assumed to be the two most
prevalent) end up with the same placement of the vmemmap region. In
a subsequent patch, we will take advantage of this, and unify the
memory maps even more.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Link: https://lore.kernel.org/r/20201008153602.9467-4-ardb@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/mm')
| -rw-r--r-- | arch/arm64/mm/init.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 7e15d92836d8..3a5e9f9298e9 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -502,6 +502,8 @@ static void __init free_unused_memmap(void) */ void __init mem_init(void) { + BUILD_BUG_ON(!is_power_of_2(sizeof(struct page))); + if (swiotlb_force == SWIOTLB_FORCE || max_pfn > PFN_DOWN(arm64_dma_phys_limit ? : arm64_dma32_phys_limit)) swiotlb_init(1); |