On Mon, Jan 25, 2016 at 08:52:12AM -0800, Laura Abbott wrote:
> create_mapping is only used in fixmap_remap_fdt. All the create_mapping
> calls need to happen on existing translation table pages without
> additional allocations. Rather than have an alloc function be called
> and fail, just set it to NULL and catch it's use.
This looks sensible to me, though I think we should rename
create_mapping to something that makes it clear that not allocating
pages is a deliberate design decision, and thus it must be called with
care.
Perhaps create_mapping_noalloc?
Thanks,
Mark.
> Signed-off-by: Laura Abbott <labb...@fedoraproject.org>
> ---
> arch/arm64/mm/mmu.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index e141762..2d6e7cf 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -116,7 +116,9 @@ static void alloc_init_pte(pmd_t *pmd, unsigned long addr,
> pte_t *pte;
>
> if (pmd_none(*pmd) || pmd_sect(*pmd)) {
> - phys_addr_t pte_phys = pgtable_alloc();
> + phys_addr_t pte_phys;
> + BUG_ON(!pgtable_alloc);
> + pte_phys = pgtable_alloc();
> pte = pte_fixmap(pte_phys);
> if (pmd_sect(*pmd))
> split_pmd(pmd, pte);
> @@ -158,7 +160,9 @@ static void alloc_init_pmd(pud_t *pud, unsigned long
> addr, unsigned long end,
> * Check for initial section mappings in the pgd/pud and remove them.
> */
> if (pud_none(*pud) || pud_sect(*pud)) {
> - phys_addr_t pmd_phys = pgtable_alloc();
> + phys_addr_t pmd_phys;
> + BUG_ON(!pgtable_alloc);
> + pmd_phys = pgtable_alloc();
> pmd = pmd_fixmap(pmd_phys);
> if (pud_sect(*pud)) {
> /*
> @@ -223,7 +227,9 @@ static void alloc_init_pud(pgd_t *pgd, unsigned long
> addr, unsigned long end,
> unsigned long next;
>
> if (pgd_none(*pgd)) {
> - phys_addr_t pud_phys = pgtable_alloc();
> + phys_addr_t pud_phys;
> + BUG_ON(!pgtable_alloc);
> + pud_phys = pgtable_alloc();
> __pgd_populate(pgd, pud_phys, PUD_TYPE_TABLE);
> }
> BUG_ON(pgd_bad(*pgd));
> @@ -319,7 +325,7 @@ static void __init create_mapping(phys_addr_t phys,
> unsigned long virt,
> return;
> }
> __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot,
> - early_pgtable_alloc);
> + NULL);
> }
>
> void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
> --
> 2.5.0
>
