The patch titled
Subject: mm/powerpc: add missing pud helpers
has been added to the -mm mm-unstable branch. Its filename is
mm-powerpc-add-missing-pud-helpers.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-powerpc-add-missing-pud-helpers.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Peter Xu <peterx@xxxxxxxxxx>
Subject: mm/powerpc: add missing pud helpers
Date: Mon, 12 Aug 2024 14:12:21 -0400
Some new helpers will be needed for pud entry updates soon. Introduce
these helpers by referencing the pmd ones. Namely:
- pudp_invalidate(): this helper invalidates a huge pud before a split
happens, so that the invalidated pud entry will make sure no race will
happen (either with software, like a concurrent zap, or hardware, like
a/d bit lost).
- pud_modify(): this helper applies a new pgprot to an existing huge pud
mapping.
For more information on why we need these two helpers, please refer to the
corresponding pmd helpers in the mprotect() code path.
Link: https://lkml.kernel.org/r/20240812181225.1360970-4-peterx@xxxxxxxxxx
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 3 ++
arch/powerpc/mm/book3s64/pgtable.c | 20 +++++++++++++++++
2 files changed, 23 insertions(+)
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h~mm-powerpc-add-missing-pud-helpers
+++ a/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -1124,6 +1124,7 @@ extern pmd_t pfn_pmd(unsigned long pfn,
extern pud_t pfn_pud(unsigned long pfn, pgprot_t pgprot);
extern pmd_t mk_pmd(struct page *page, pgprot_t pgprot);
extern pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot);
+extern pud_t pud_modify(pud_t pud, pgprot_t newprot);
extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd);
extern void set_pud_at(struct mm_struct *mm, unsigned long addr,
@@ -1384,6 +1385,8 @@ static inline pgtable_t pgtable_trans_hu
#define __HAVE_ARCH_PMDP_INVALIDATE
extern pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp);
+extern pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
+ pud_t *pudp);
#define pmd_move_must_withdraw pmd_move_must_withdraw
struct spinlock;
--- a/arch/powerpc/mm/book3s64/pgtable.c~mm-powerpc-add-missing-pud-helpers
+++ a/arch/powerpc/mm/book3s64/pgtable.c
@@ -176,6 +176,17 @@ pmd_t pmdp_invalidate(struct vm_area_str
return __pmd(old_pmd);
}
+pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
+ pud_t *pudp)
+{
+ unsigned long old_pud;
+
+ VM_WARN_ON_ONCE(!pud_present(*pudp));
+ old_pud = pud_hugepage_update(vma->vm_mm, address, pudp, _PAGE_PRESENT, _PAGE_INVALID);
+ flush_pud_tlb_range(vma, address, address + HPAGE_PUD_SIZE);
+ return __pud(old_pud);
+}
+
pmd_t pmdp_huge_get_and_clear_full(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp, int full)
{
@@ -259,6 +270,15 @@ pmd_t pmd_modify(pmd_t pmd, pgprot_t new
pmdv &= _HPAGE_CHG_MASK;
return pmd_set_protbits(__pmd(pmdv), newprot);
}
+
+pud_t pud_modify(pud_t pud, pgprot_t newprot)
+{
+ unsigned long pudv;
+
+ pudv = pud_val(pud);
+ pudv &= _HPAGE_CHG_MASK;
+ return pud_set_protbits(__pud(pudv), newprot);
+}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
/* For use by kexec, called with MMU off */
_
Patches currently in -mm which might be from peterx@xxxxxxxxxx are
mm-dax-dump-start-address-in-fault-handler.patch
mm-mprotect-push-mmu-notifier-to-puds.patch
mm-powerpc-add-missing-pud-helpers.patch
mm-x86-make-pud_leaf-only-care-about-pse-bit.patch
mm-x86-implement-arch_check_zapped_pud.patch
mm-x86-add-missing-pud-helpers.patch
mm-mprotect-fix-dax-pud-handlings.patch
