From: Jinjiang Tu <tujinjiang@huawei.com>
To: <akpm@linux-foundation.org>, <david@kernel.org>, <ljs@kernel.org>,
<catalin.marinas@arm.com>, <will@kernel.org>,
<mark.rutland@arm.com>, <ryan.roberts@arm.com>,
<peterx@redhat.com>, <dave.jiang@intel.com>,
<linux-arm-kernel@lists.infradead.org>, <linux-mm@kvack.org>
Cc: <wangkefeng.wang@huawei.com>, <sunnanyong@huawei.com>,
<tujinjiang@huawei.com>
Subject: [PATCH 3/3] arm64: Add support for PUD THP
Date: Wed, 9 Sep 2026 17:00:18 +0800 [thread overview]
Message-ID: <20260909090018.1991485-4-tujinjiang@huawei.com> (raw)
In-Reply-To: <20260909090018.1991485-1-tujinjiang@huawei.com>
Add the necessary page table functions to deal with PUD THP, this enables
PUD THP for DAX and pfnmap.
I tested with CONFIG_DEBUG_VM_PGTABLE and CONFIG_PAGE_TABLE_CHECK
enabled. I wrote a test driver that invokes vmf_insert_pfn_pud() in
the huge_fault callback. Page table setup works as expected with no
errors, and userspace read/write access to the PUD-sized mapping is
verified correct.
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
---
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/pgtable.h | 52 ++++++++++++++++++++++++++++++++
2 files changed, 53 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b5a51b0ef944..8a7ca1863595 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -173,6 +173,7 @@ config ARM64
select HAVE_ARCH_THREAD_STRUCT_WHITELIST
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
+ select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if PAGE_SIZE_4KB
select HAVE_ARCH_VMAP_STACK
select HAVE_ARM_SMCCC
select HAVE_ASM_MODVERSIONS
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 427ea3d2bac7..fdc338970934 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -611,6 +611,11 @@ static inline pmd_t pmd_mkhuge(pmd_t pmd)
#define pmd_mkspecial(pmd) pte_pmd(pte_mkspecial(pmd_pte(pmd)))
#endif
+#ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP
+#define pud_special(pud) pte_special(pud_pte(pud))
+#define pud_mkspecial(pud) pte_pud(pte_mkspecial(pud_pte(pud)))
+#endif
+
#define __pmd_to_phys(pmd) __pte_to_phys(pmd_pte(pmd))
#define __phys_to_pmd_val(phys) __phys_to_pte_val(phys)
#define pmd_pfn(pmd) ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT)
@@ -619,8 +624,15 @@ static inline pmd_t pmd_mkhuge(pmd_t pmd)
#define pud_young(pud) pte_young(pud_pte(pud))
#define pud_mkyoung(pud) pte_pud(pte_mkyoung(pud_pte(pud)))
#define pud_mkwrite_novma(pud) pte_pud(pte_mkwrite_novma(pud_pte(pud)))
+#define pud_mkwrite(pud) pud_mkwrite_novma(pud)
#define pud_mkvalid_k(pud) pte_pud(pte_mkvalid_k(pud_pte(pud)))
#define pud_write(pud) pte_write(pud_pte(pud))
+#define pud_dirty(pud) pte_dirty(pud_pte(pud))
+#define pud_wrprotect(pud) pte_pud(pte_wrprotect(pud_pte(pud)))
+#define pud_mkdirty(pud) pte_pud(pte_mkdirty(pud_pte(pud)))
+#define pud_mkold(pud) pte_pud(pte_mkold(pud_pte(pud)))
+#define pud_mkinvalid(pud) pte_pud(pte_mkinvalid(pud_pte(pud)))
+#define pud_mkclean(pud) pte_pud(pte_mkclean(pud_pte(pud)))
static inline pud_t pud_mkhuge(pud_t pud)
{
@@ -871,6 +883,13 @@ static inline bool pud_leaf(pud_t pud)
#define pud_user(pud) pte_user(pud_pte(pud))
#define pud_user_exec(pud) pte_user_exec(pud_pte(pud))
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static inline int pud_trans_huge(pud_t pud)
+{
+ return pud_present(pud) && !pud_table(__pud(pud_val(pud) | PTE_VALID));
+}
+#endif
+
static inline bool pgtable_l4_enabled(void);
static inline void set_pud(pud_t *pudp, pud_t pud)
@@ -1237,6 +1256,11 @@ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
}
+static inline pud_t pud_modify(pud_t pud, pgprot_t newprot)
+{
+ return pte_pud(pte_modify(pud_pte(pud), newprot));
+}
+
extern int __ptep_set_access_flags_anysz(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep,
pte_t entry, int dirty,
@@ -1261,6 +1285,16 @@ static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
}
#endif
+#ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP
+static inline int pudp_set_access_flags(struct vm_area_struct *vma,
+ unsigned long address, pud_t *pudp,
+ pud_t entry, int dirty)
+{
+ return __ptep_set_access_flags_anysz(vma, address, (pte_t *)pudp,
+ pud_pte(entry), dirty, PUD_SIZE);
+}
+#endif
+
#ifdef CONFIG_PAGE_TABLE_CHECK
static inline bool pte_user_accessible_page(struct mm_struct *mm, unsigned long addr, pte_t pte)
{
@@ -1335,6 +1369,14 @@ static inline bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG */
+#ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP
+static inline bool pudp_test_and_clear_young(struct vm_area_struct *vma,
+ unsigned long address, pud_t *pudp)
+{
+ return __ptep_test_and_clear_young(vma, address, (pte_t *)pudp);
+}
+#endif
+
static inline pte_t __ptep_get_and_clear_anysz(struct mm_struct *mm,
unsigned long address,
pte_t *ptep,
@@ -1497,6 +1539,15 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
}
#endif
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static inline pud_t pudp_establish(struct vm_area_struct *vma,
+ unsigned long address, pud_t *pudp, pud_t pud)
+{
+ page_table_check_pud_set(vma->vm_mm, address, pudp, pud);
+ return __pud(xchg_relaxed(&pud_val(*pudp), pud_val(pud)));
+}
+#endif
+
/*
* Encode and decode a swap entry:
* bits 0-1: present (must be zero)
@@ -1571,6 +1622,7 @@ static inline void update_mmu_cache_range(struct vm_fault *vmf,
#define update_mmu_cache(vma, addr, ptep) \
update_mmu_cache_range(NULL, vma, addr, ptep, 1)
#define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
+#define update_mmu_cache_pud(vma, address, pud) do { } while (0)
#ifdef CONFIG_ARM64_PA_BITS_52
#define phys_to_ttbr(addr) (((addr) | ((addr) >> 46)) & TTBR_BADDR_MASK_52)
--
2.43.0
prev parent reply other threads:[~2026-09-09 9:28 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-09 9:00 [PATCH 0/3] arm64: Add support for PUD THP Jinjiang Tu
2026-09-09 9:00 ` [PATCH 1/3] mm: define generic pudp_invalidate() implementation Jinjiang Tu
2026-09-09 10:24 ` David Hildenbrand (Arm)
2026-09-11 2:28 ` Jinjiang Tu
2026-09-09 9:00 ` [PATCH 2/3] arm64: simplify pmd_special and pmd_mkspecial Jinjiang Tu
2026-09-09 9:00 ` Jinjiang Tu [this message]
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