Commit ef493d23 authored by Ryan Roberts's avatar Ryan Roberts Committed by Will Deacon
Browse files

arm64/mm: Refactor __set_ptes() and __ptep_get_and_clear() 



Refactor __set_ptes(), set_pmd_at() and set_pud_at() so that they are
all a thin wrapper around a new common __set_ptes_anysz(), which takes
pgsize parameter. Additionally, refactor __ptep_get_and_clear() and
pmdp_huge_get_and_clear() to use a new common
__ptep_get_and_clear_anysz() which also takes a pgsize parameter.

These changes will permit the huge_pte API to efficiently batch-set
pgtable entries and take advantage of the future barrier optimizations.
Additionally since the new *_anysz() helpers call the correct
page_table_check_*_set() API based on pgsize, this means that huge_ptes
will be able to get proper coverage. Currently the huge_pte API always
uses the pte API which assumes an entry only covers a single page.

Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarRyan Roberts <ryan.roberts@arm.com>
Reviewed-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Tested-by: default avatarLuiz Capitulino <luizcap@redhat.com>
Link: https://lore.kernel.org/r/20250422081822.1836315-5-ryan.roberts@arm.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 91e40668

arch/arm64/include/asm/pgtable.h

+73 −41
Original line number Diff line number Diff line
@@ -423,23 +423,6 @@ static inline pte_t pte_advance_pfn(pte_t pte, unsigned long nr) 
	return pfn_pte(pte_pfn(pte) + nr, pte_pgprot(pte));

}



static inline void __set_ptes(struct mm_struct *mm,

			      unsigned long __always_unused addr,

			      pte_t *ptep, pte_t pte, unsigned int nr)

{

	page_table_check_ptes_set(mm, ptep, pte, nr);

	__sync_cache_and_tags(pte, nr);



	for (;;) {

		__check_safe_pte_update(mm, ptep, pte);

		__set_pte(ptep, pte);

		if (--nr == 0)

			break;

		ptep++;

		pte = pte_advance_pfn(pte, 1);

	}

}



/*

 * Hugetlb definitions.

 */
@@ -649,30 +632,62 @@ static inline pgprot_t pud_pgprot(pud_t pud) 
	return __pgprot(pud_val(pfn_pud(pfn, __pgprot(0))) ^ pud_val(pud));

}



static inline void __set_pte_at(struct mm_struct *mm,

				unsigned long __always_unused addr,

				pte_t *ptep, pte_t pte, unsigned int nr)

static inline void __set_ptes_anysz(struct mm_struct *mm, pte_t *ptep,

				    pte_t pte, unsigned int nr,

				    unsigned long pgsize)

{

	__sync_cache_and_tags(pte, nr);

	unsigned long stride = pgsize >> PAGE_SHIFT;



	switch (pgsize) {

	case PAGE_SIZE:

		page_table_check_ptes_set(mm, ptep, pte, nr);

		break;

	case PMD_SIZE:

		page_table_check_pmds_set(mm, (pmd_t *)ptep, pte_pmd(pte), nr);

		break;

#ifndef __PAGETABLE_PMD_FOLDED

	case PUD_SIZE:

		page_table_check_puds_set(mm, (pud_t *)ptep, pte_pud(pte), nr);

		break;

#endif

	default:

		VM_WARN_ON(1);

	}



	__sync_cache_and_tags(pte, nr * stride);



	for (;;) {

		__check_safe_pte_update(mm, ptep, pte);

		__set_pte(ptep, pte);

		if (--nr == 0)

			break;

		ptep++;

		pte = pte_advance_pfn(pte, stride);

	}

}



static inline void __set_ptes(struct mm_struct *mm,

			      unsigned long __always_unused addr,

			      pte_t *ptep, pte_t pte, unsigned int nr)

{

	__set_ptes_anysz(mm, ptep, pte, nr, PAGE_SIZE);

}



static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,

			      pmd_t *pmdp, pmd_t pmd)

static inline void __set_pmds(struct mm_struct *mm,

			      unsigned long __always_unused addr,

			      pmd_t *pmdp, pmd_t pmd, unsigned int nr)

{

	page_table_check_pmd_set(mm, pmdp, pmd);

	return __set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd),

						PMD_SIZE >> PAGE_SHIFT);

	__set_ptes_anysz(mm, (pte_t *)pmdp, pmd_pte(pmd), nr, PMD_SIZE);

}

#define set_pmd_at(mm, addr, pmdp, pmd) __set_pmds(mm, addr, pmdp, pmd, 1)



static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,

			      pud_t *pudp, pud_t pud)

static inline void __set_puds(struct mm_struct *mm,

			      unsigned long __always_unused addr,

			      pud_t *pudp, pud_t pud, unsigned int nr)

{

	page_table_check_pud_set(mm, pudp, pud);

	return __set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud),

						PUD_SIZE >> PAGE_SHIFT);

	__set_ptes_anysz(mm, (pte_t *)pudp, pud_pte(pud), nr, PUD_SIZE);

}

#define set_pud_at(mm, addr, pudp, pud) __set_puds(mm, addr, pudp, pud, 1)



#define __p4d_to_phys(p4d)	__pte_to_phys(p4d_pte(p4d))

#define __phys_to_p4d_val(phys)	__phys_to_pte_val(phys)
@@ -1301,16 +1316,37 @@ static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma, 
}

#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG */



static inline pte_t __ptep_get_and_clear(struct mm_struct *mm,

				       unsigned long address, pte_t *ptep)

static inline pte_t __ptep_get_and_clear_anysz(struct mm_struct *mm,

					       pte_t *ptep,

					       unsigned long pgsize)

{

	pte_t pte = __pte(xchg_relaxed(&pte_val(*ptep), 0));



	switch (pgsize) {

	case PAGE_SIZE:

		page_table_check_pte_clear(mm, pte);

		break;

	case PMD_SIZE:

		page_table_check_pmd_clear(mm, pte_pmd(pte));

		break;

#ifndef __PAGETABLE_PMD_FOLDED

	case PUD_SIZE:

		page_table_check_pud_clear(mm, pte_pud(pte));

		break;

#endif

	default:

		VM_WARN_ON(1);

	}



	return pte;

}



static inline pte_t __ptep_get_and_clear(struct mm_struct *mm,

				       unsigned long address, pte_t *ptep)

{

	return __ptep_get_and_clear_anysz(mm, ptep, PAGE_SIZE);

}



static inline void __clear_full_ptes(struct mm_struct *mm, unsigned long addr,

				pte_t *ptep, unsigned int nr, int full)

{
@@ -1347,11 +1383,7 @@ static inline pte_t __get_and_clear_full_ptes(struct mm_struct *mm, 
static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,

					    unsigned long address, pmd_t *pmdp)

{

	pmd_t pmd = __pmd(xchg_relaxed(&pmd_val(*pmdp), 0));



	page_table_check_pmd_clear(mm, pmd);



	return pmd;

	return pte_pmd(__ptep_get_and_clear_anysz(mm, (pte_t *)pmdp, PMD_SIZE));

}

#endif /* CONFIG_TRANSPARENT_HUGEPAGE */