[PATCH v3 07/14] powerpc/32: drop get_pteptr()

Mike Rapoport
2020-02-27T08:46:01Z

From: Christophe Leroy <christophe.leroy@c-s.fr>

Commit 8d30c14cab30 ("powerpc/mm: Rework I$/D$ coherency (v3)") and
commit 90ac19a8b21b ("[POWERPC] Abolish iopa(), mm_ptov(),
io_block_mapping() from arch/powerpc") removed the use of get_pteptr()
outside of mm/pgtable_32.c

In mm/pgtable_32.c, the only user of get_pteptr() is __change_page_attr()
which operates on kernel context and on lowmem pages only.

Move page table traversal to __change_page_attr() and drop get_pteptr().

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
arch/powerpc/mm/pgtable_32.c | 43 ++++++------------------------------
1 file changed, 7 insertions(+), 36 deletions(-)

diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index 5fb90edd865e..4894555622d7 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -121,53 +121,24 @@ void __init mapin_ram(void)
}
}

-/* Scan the real Linux page tables and return a PTE pointer for
- * a virtual address in a context.
- * Returns true (1) if PTE was found, zero otherwise. The pointer to
- * the PTE pointer is unmodified if PTE is not found.
- */
-static int
-get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp)
-{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *pte;
- int retval = 0;
-
- pgd = pgd_offset(mm, addr & PAGE_MASK);
- if (pgd) {
- pud = pud_offset(pgd, addr & PAGE_MASK);
- if (pud && pud_present(*pud)) {
- pmd = pmd_offset(pud, addr & PAGE_MASK);
- if (pmd_present(*pmd)) {
- pte = pte_offset_map(pmd, addr & PAGE_MASK);
- if (pte) {
- retval = 1;
- *ptep = pte;
- if (pmdp)
- *pmdp = pmd;
- /* XXX caller needs to do pte_unmap, yuck */
- }
- }
- }
- }
- return(retval);
-}
-
static int __change_page_attr_noflush(struct page *page, pgprot_t prot)
{
pte_t *kpte;
pmd_t *kpmd;
- unsigned long address;
+ unsigned long address, va;

BUG_ON(PageHighMem(page));
address = (unsigned long)page_address(page);
+ va = address & PAGE_MASK;

if (v_block_mapped(address))
return 0;
- if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
+
+ kpmd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
+ if (!pmd_present(*kpmd))
return -EINVAL;
+
+ kpte = pte_offset_map(kpmd, va);
__set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0);
pte_unmap(kpte);

--
2.24.0