Commit 6ba1917a authored Mar 03, 2026 by Vishal Moola (Oracle) Committed by Dave Hansen Mar 04, 2026

x86/mm/pat: Convert pmd code to use page table apis



Use the ptdesc APIs for all page table allocation and free sites to allow
their separate allocation from struct page in the future. Convert the PMD
allocation and free sites to use the generic page table APIs, as they
already use ptdescs.

Pass through init_mm since these are kernel page tables, as
pmd_alloc_one() requires it to identify kernel page tables. Because the
generic implementation does not use the second argument, pass a
placeholder to avoid reimplementing it or risking breakage on other
architectures.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260303194828.1406905-3-vishal.moola@gmail.com

parent c22ca4a9

arch/x86/mm/pat/set_memory.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -1420,7 +1420,7 @@ static bool try_to_free_pmd_page(pmd_t *pmd)
		if (!pmd_none(pmd[i]))
		return false;

		free_page((unsigned long)pmd);
		pmd_free(&init_mm, pmd);
		return true;
		}

		@@ -1549,7 +1549,11 @@ static int alloc_pte_page(pmd_t *pmd)

		static int alloc_pmd_page(pud_t *pud)
		{
		pmd_t pmd = (pmd_t )get_zeroed_page(GFP_KERNEL);
		/*
		* Pass 0 as a placeholder for the second argument, since the
		* generic implementation of pmd_alloc_one() does not use it.
		*/
		pmd_t *pmd = pmd_alloc_one(&init_mm, 0);
		if (!pmd)
		return -1;