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powerpc/mm/book3s: Check for pmd_large instead of pmd_trans_huge

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Update few code paths to check for pmd_large.

set_pmd_at:
We want to use this to store swap pte at pmd level. For swap ptes we don't want
to set H_PAGE_THP_HUGE. Hence check for pmd_large in set_pmd_at. This remove
the false WARN_ON when using this with swap pmd entry.

pmd_page:
We don't really use them on pmd migration entries. But they can also work with
migration entries and we don't differentiate at the pte level. Hence update
pmd_page to work with pmd migration entries too

__find_linux_pte:
lockless page table walk need to handle pmd migration entries. pmd_trans_huge
check will return false on them. We don't set thp = 1 for such entries, but
update hpage_shift correctly. Without this we will walk pmd migration entries
as a pte page pointer which is wrong.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Aneesh Kumar K.V 2018-09-20 23:39:44 +05:30 committed by Michael Ellerman
parent f1981b5b30
commit ae28f17b5e
3 changed files with 8 additions and 4 deletions
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8
arch/powerpc/mm/hugetlbpage.c
View file

@ -837,8 +837,12 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
ret_pte = (pte_t *) pmdp;
goto out;
}
if (pmd_huge(pmd)) {
/*
* pmd_large check below will handle the swap pmd pte
* we need to do both the check because they are config
* dependent.
*/
if (pmd_huge(pmd) || pmd_large(pmd)) {
ret_pte = (pte_t *) pmdp;
goto out;
} else if (is_hugepd(__hugepd(pmd_val(pmd))))

2
arch/powerpc/mm/pgtable-book3s64.c
View file

@ -75,7 +75,7 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
*/
WARN_ON(pte_val(pmd_pte(*pmdp)) & _PAGE_PRESENT);
assert_spin_locked(pmd_lockptr(mm, pmdp));
WARN_ON(!(pmd_trans_huge(pmd) || pmd_devmap(pmd)));
WARN_ON(!(pmd_large(pmd) || pmd_devmap(pmd)));
#endif
trace_hugepage_set_pmd(addr, pmd_val(pmd));
return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));

2
arch/powerpc/mm/pgtable_64.c
View file

@ -306,7 +306,7 @@ struct page *pud_page(pud_t pud)
*/
struct page *pmd_page(pmd_t pmd)
{
if (pmd_trans_huge(pmd) || pmd_huge(pmd) || pmd_devmap(pmd))
if (pmd_large(pmd) || pmd_huge(pmd) || pmd_devmap(pmd))
return pte_page(pmd_pte(pmd));
return virt_to_page(pmd_page_vaddr(pmd));
}