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arm64: mm: don't call page table ctors for init_mm

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init_mm doesn't require page table lock to be initialized at
any level. Add a separate page table allocator for it, and the
new one skips page table ctors.

The ctors allocate memory when ALLOC_SPLIT_PTLOCKS is set. Not
calling them avoids memory leak in case we call pte_free_kernel()
on init_mm.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Yu Zhao <yuzhao@google.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Yu Zhao 2019-03-11 18:57:47 -06:00 committed by Will Deacon
parent 90292aca98
commit 369aaab845
1 changed files with 13 additions and 2 deletions
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15
arch/arm64/mm/mmu.c
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@ -371,6 +371,16 @@ static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
} while (pgdp++, addr = next, addr != end);
}
static phys_addr_t pgd_kernel_pgtable_alloc(int shift)
{
void *ptr = (void *)__get_free_page(PGALLOC_GFP);
BUG_ON(!ptr);
/* Ensure the zeroed page is visible to the page table walker */
dsb(ishst);
return __pa(ptr);
}
static phys_addr_t pgd_pgtable_alloc(int shift)
{
void *ptr = (void *)__get_free_page(PGALLOC_GFP);
@ -595,7 +605,7 @@ static int __init map_entry_trampoline(void)
/* Map only the text into the trampoline page table */
memset(tramp_pg_dir, 0, PGD_SIZE);
__create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE,
prot, pgd_pgtable_alloc, 0);
prot, pgd_kernel_pgtable_alloc, 0);
/* Map both the text and data into the kernel page table */
__set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot);
@ -1067,7 +1077,8 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
__create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start),
size, PAGE_KERNEL, pgd_pgtable_alloc, flags);
size, PAGE_KERNEL, pgd_kernel_pgtable_alloc,
flags);
return __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT,
altmap, want_memblock);