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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2016-03-30 16:46:00 +0200 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2016-04-14 16:31:49 +0100 |
| commit | 3e1907d5bf5a1e0b182ee599f92586f0165029e2 (patch) | |
| tree | 1882d1a6d4532815ebe3090d12d3920f0cef3243 /arch/arm64/mm/init.c | |
| parent | e44308e62e19b42810207780a2a32148af0cb5d9 (diff) | |
| download | op-kernel-dev-3e1907d5bf5a1e0b182ee599f92586f0165029e2.zip op-kernel-dev-3e1907d5bf5a1e0b182ee599f92586f0165029e2.tar.gz | |
arm64: mm: move vmemmap region right below the linear region
This moves the vmemmap region right below PAGE_OFFSET, aka the start
of the linear region, and redefines its size to be a power of two.
Due to the placement of PAGE_OFFSET in the middle of the address space,
whose size is a power of two as well, this guarantees that virt to
page conversions and vice versa can be implemented efficiently, by
masking and shifting rather than ordinary arithmetic.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/mm/init.c')
| -rw-r--r-- | arch/arm64/mm/init.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 89376f3..d55d720 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -412,6 +412,10 @@ void __init mem_init(void) MLK_ROUNDUP(__start_rodata, _etext), MLK_ROUNDUP(__init_begin, __init_end), MLK_ROUNDUP(_sdata, _edata)); + pr_cont(" fixed : 0x%16lx - 0x%16lx (%6ld KB)\n", + MLK(FIXADDR_START, FIXADDR_TOP)); + pr_cont(" PCI I/O : 0x%16lx - 0x%16lx (%6ld MB)\n", + MLM(PCI_IO_START, PCI_IO_END)); #ifdef CONFIG_SPARSEMEM_VMEMMAP pr_cont(" vmemmap : 0x%16lx - 0x%16lx (%6ld GB maximum)\n" " 0x%16lx - 0x%16lx (%6ld MB actual)\n", @@ -420,10 +424,6 @@ void __init mem_init(void) MLM((unsigned long)phys_to_page(memblock_start_of_DRAM()), (unsigned long)virt_to_page(high_memory))); #endif - pr_cont(" fixed : 0x%16lx - 0x%16lx (%6ld KB)\n", - MLK(FIXADDR_START, FIXADDR_TOP)); - pr_cont(" PCI I/O : 0x%16lx - 0x%16lx (%6ld MB)\n", - MLM(PCI_IO_START, PCI_IO_END)); pr_cont(" memory : 0x%16lx - 0x%16lx (%6ld MB)\n", MLM(__phys_to_virt(memblock_start_of_DRAM()), (unsigned long)high_memory)); @@ -440,6 +440,12 @@ void __init mem_init(void) BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64); #endif + /* + * Make sure we chose the upper bound of sizeof(struct page) + * correctly. + */ + BUILD_BUG_ON(sizeof(struct page) > (1 << STRUCT_PAGE_MAX_SHIFT)); + if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) { extern int sysctl_overcommit_memory; /* |
