Re: [PATCH 1/3] mm: define generic pudp_invalidate() implementation

在 2026/9/9 18:24, David Hildenbrand (Arm) 写道:

On 9/9/26 11:00, Jinjiang Tu wrote:

quoted

x86 and riscv have identical pudp_invalidate() implementations. Move it to
mm/pgtable-generic.c with the __HAVE_ARCH_PUDP_INVALIDATE override guard.
PowerPC keeps its own implementation. In the later patch, arm64 will use
the generic implementation too.

No functional change intended.

Signed-off-by: Jinjiang Tu <redacted>
---
  arch/powerpc/include/asm/book3s/64/pgtable.h |  1 +
  arch/riscv/include/asm/pgtable.h             |  3 ---
  arch/riscv/mm/pgtable.c                      |  9 ---------
  arch/x86/include/asm/pgtable.h               |  3 ---
  arch/x86/mm/pgtable.c                        | 12 ------------
  include/linux/pgtable.h                      |  7 +++++++
  mm/pgtable-generic.c                         | 14 ++++++++++++++
  7 files changed, 22 insertions(+), 27 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index f4db7d7fbd5c..55d33c5537f1 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h

@@ -1419,6 +1419,7 @@ static inline pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm,
  #define __HAVE_ARCH_PMDP_INVALIDATE
  extern pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
  			     pmd_t *pmdp);
+#define __HAVE_ARCH_PUDP_INVALIDATE
  extern pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
  			     pud_t *pudp);
  

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 40b1ed4f3ea8..327fa378032b 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h

@@ -1159,9 +1159,6 @@ static inline pud_t pud_mkinvalid(pud_t pud)
  	return __pud(pud_val(pud) & ~(_PAGE_PRESENT | _PAGE_PROT_NONE));
  }
  
-extern pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
-			     pud_t *pudp);
-
  static inline pud_t pud_modify(pud_t pud, pgprot_t newprot)
  {
  	return pte_pud(pte_modify(pud_pte(pud), newprot));

diff --git a/arch/riscv/mm/pgtable.c b/arch/riscv/mm/pgtable.c
index 9c4427d0b187..156e385e7db4 100644
--- a/arch/riscv/mm/pgtable.c
+++ b/arch/riscv/mm/pgtable.c

@@ -154,15 +154,6 @@ pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
  	return pmd;
  }
  
-pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
-		      pud_t *pudp)
-{
-	VM_WARN_ON_ONCE(!pud_present(*pudp));
-	pud_t old = pudp_establish(vma, address, pudp, pud_mkinvalid(*pudp));
-
-	flush_pud_tlb_range(vma, address, address + HPAGE_PUD_SIZE);
-	return old;
-}
  #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
  
  pte_t pte_mkwrite(pte_t pte, struct vm_area_struct *vma)

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index d5f4917c1edc..97051c02385e 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h

@@ -1387,9 +1387,6 @@ static inline pud_t pudp_establish(struct vm_area_struct *vma,
  extern pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma,
  				unsigned long address, pmd_t *pmdp);
  
-pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
-		      pud_t *pudp);
-
  /*
   * Page table pages are page-aligned.  The lower half of the top
   * level is used for userspace and the top half for the kernel.

diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index cb03f5a2b243..0945908631dc 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c

@@ -519,18 +519,6 @@ pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma, unsigned long address,
  }
  #endif
  
-#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
-	defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
-pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
-		     pud_t *pudp)
-{
-	VM_WARN_ON_ONCE(!pud_present(*pudp));
-	pud_t old = pudp_establish(vma, address, pudp, pud_mkinvalid(*pudp));
-	flush_pud_tlb_range(vma, address, address + HPAGE_PUD_SIZE);
-	return old;
-}
-#endif
-
  /**
   * reserve_top_address - Reserve a hole in the top of the kernel address space
   * @reserve: Size of hole to reserve

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 8c093c119e5a..32173005b087 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h

@@ -1318,6 +1318,13 @@ extern pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma,
  				unsigned long address, pmd_t *pmdp);
  #endif
  
+#ifndef __HAVE_ARCH_PUDP_INVALIDATE
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+extern pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
+			     pud_t *pudp);

No "extern" please.

Will update it.

Staring at this file, I do wonder why we are not smarter about combining blocks. E.g., here simply:'

Do you mean merging all #ifdef CONFIG_TRANSPARENT_HUGEPAGE blocks? There are many of them scattered
across include/linux/pgtable.h and arch/arm64/include/asm/pgtable.h. They are intentionally kept
separate to group the PTE, PMD, and PUD level variants of the same operation together. For example,
ptep_set_access_flags, pmdp_set_access_flags, and pudp_set_access_flags are placed adjacently.