Commit 1d6991f2 authored Mar 03, 2025 by Anshuman Khandual Committed by Liu Shixin Mar 03, 2025

arm64/mm: Re-organize arch_make_huge_pte()

mainline inclusion
from mainline-v6.13-rc1
commit f8192813dcbe6d27e7031d9d353ea1fcc67052fd
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IBPX2S

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f8192813dcbe6d27e7031d9d353ea1fcc67052fd



--------------------------------

Core HugeTLB defines a fallback definition for arch_make_huge_pte(), which
calls platform provided pte_mkhuge(). But if any platform already provides
an override for arch_make_huge_pte(), then it does not need to provide the
helper pte_mkhuge().

arm64 override for arch_make_huge_pte() calls pte_mkhuge() internally, thus
creating an impression, that both of these callbacks are being used in core
HugeTLB and hence required to be defined. This drops off pte_mkhuge() which
was never required to begin with as there could not be any section mappings
at the PTE level. Re-organize arch_make_huge_pte() based on requested page
size and create the entry for the applicable page table level as needed. It
also removes a redundancy of clearing PTE_TABLE_BIT bit followed by setting
both PTE_TABLE_BIT and PTE_VALID bits (via PTE_TYPE_MASK) in the pte, while
creating CONT_PTE_SIZE size entries.

Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20241029044529.2624785-1-anshuman.khandual@arm.com


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Liu Shixin <liushixin2@huawei.com>

parent 8c445538

arch/arm64/include/asm/pgtable.h

+0 −5

Original line number	Diff line number	Diff line
		@@ -378,11 +378,6 @@ static inline void __set_ptes(struct mm_struct *mm,
		}
		}

		/*
		* Huge pte definitions.
		*/
		#define pte_mkhuge(pte) (__pte(pte_val(pte) & ~PTE_TABLE_BIT))

		/*
		* Hugetlb definitions.
		*/

arch/arm64/mm/hugetlbpage.c

+16 −5

Original line number	Diff line number	Diff line
		@@ -379,14 +379,25 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
		{
		size_t pagesize = 1UL << shift;

		entry = pte_mkhuge(entry);
		if (pagesize == CONT_PTE_SIZE) {
		entry = pte_mkcont(entry);
		} else if (pagesize == CONT_PMD_SIZE) {
		switch (pagesize) {
		#ifndef __PAGETABLE_PMD_FOLDED
		case PUD_SIZE:
		entry = pud_pte(pud_mkhuge(pte_pud(entry)));
		break;
		#endif
		case CONT_PMD_SIZE:
		entry = pmd_pte(pmd_mkcont(pte_pmd(entry)));
		} else if (pagesize != PUD_SIZE && pagesize != PMD_SIZE) {
		fallthrough;
		case PMD_SIZE:
		entry = pmd_pte(pmd_mkhuge(pte_pmd(entry)));
		break;
		case CONT_PTE_SIZE:
		entry = pte_mkcont(entry);
		break;
		default:
		pr_warn("%s: unrecognized huge page size 0x%lx\n",
		__func__, pagesize);
		break;
		}
		return entry;
		}