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Message-ID: <20250205151003.88959-7-ryan.roberts@arm.com>
Date: Wed, 5 Feb 2025 15:09:46 +0000
From: Ryan Roberts <ryan.roberts@....com>
To: Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will@...nel.org>,
Muchun Song <muchun.song@...ux.dev>,
Pasha Tatashin <pasha.tatashin@...een.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Uladzislau Rezki <urezki@...il.com>,
Christoph Hellwig <hch@...radead.org>,
Mark Rutland <mark.rutland@....com>,
Ard Biesheuvel <ardb@...nel.org>,
Anshuman Khandual <anshuman.khandual@....com>,
Dev Jain <dev.jain@....com>,
Alexandre Ghiti <alexghiti@...osinc.com>,
Steve Capper <steve.capper@...aro.org>,
Kevin Brodsky <kevin.brodsky@....com>
Cc: Ryan Roberts <ryan.roberts@....com>,
linux-arm-kernel@...ts.infradead.org,
linux-mm@...ck.org,
linux-kernel@...r.kernel.org
Subject: [PATCH v1 06/16] 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 generic ___set_ptes(), which takes pgsize
parameter. This cleans up the code to remove the confusing
__set_pte_at() (which was only ever used for pmd/pud) and will allow us
to perform future barrier optimizations in a single place. Additionally,
it will permit the huge_pte API to efficiently batch-set pgtable entries
and take advantage of the future barrier optimizations.
___set_ptes() calls the correct page_table_check_*_set() function based
on the pgsize. This means that huge_ptes be able to get proper coverage
regardless of their size, once it's plumbed into huge_pte. Currently the
huge_pte API always uses the pte API which assumes an entry only covers
a single page.
While we are at it, refactor __ptep_get_and_clear() and
pmdp_huge_get_and_clear() to use a common ___ptep_get_and_clear() which
also takes a pgsize parameter. This will provide the huge_pte API the
means to clear ptes corresponding with the way they were set.
Signed-off-by: Ryan Roberts <ryan.roberts@....com>
---
arch/arm64/include/asm/pgtable.h | 108 +++++++++++++++++++------------
1 file changed, 67 insertions(+), 41 deletions(-)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 0b2a2ad1b9e8..3b55d9a15f05 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -420,23 +420,6 @@ 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.
*/
@@ -641,30 +624,59 @@ 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(struct mm_struct *mm, pte_t *ptep, pte_t pte,
+ unsigned int nr, unsigned long pgsize)
{
- __sync_cache_and_tags(pte, nr);
- __check_safe_pte_update(mm, ptep, pte);
- __set_pte(ptep, pte);
+ 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;
+ case PUD_SIZE:
+ page_table_check_puds_set(mm, (pud_t *)ptep, pte_pud(pte), nr);
+ break;
+ 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_pmd_at(struct mm_struct *mm, unsigned long addr,
- pmd_t *pmdp, pmd_t pmd)
+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_pmd_set(mm, pmdp, pmd);
- return __set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd),
- PMD_SIZE >> PAGE_SHIFT);
+ ___set_ptes(mm, ptep, pte, nr, PAGE_SIZE);
}
-static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
- pud_t *pudp, pud_t pud)
+static inline void __set_pmds(struct mm_struct *mm,
+ unsigned long __always_unused addr,
+ pmd_t *pmdp, pmd_t pmd, unsigned int nr)
+{
+ ___set_ptes(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_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(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)
@@ -1276,16 +1288,34 @@ 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(struct mm_struct *mm, pte_t *ptep,
+ unsigned long pgsize)
{
pte_t pte = __pte(xchg_relaxed(&pte_val(*ptep), 0));
- page_table_check_pte_clear(mm, pte);
+ 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;
+ case PUD_SIZE:
+ page_table_check_pud_clear(mm, pte_pud(pte));
+ break;
+ 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(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)
{
@@ -1322,11 +1352,7 @@ 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(mm, (pte_t *)pmdp, PMD_SIZE));
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
--
2.43.0
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