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powerpc/mm: use set_pte_at_unchecked() for internal usages

In the new set_ptes() API, set_pte_at() (a special case of set_ptes()) is
intended to be instrumented by the page table check facility. There are
however several other routines that constitute the API for setting page
table entries, including set_pmd_at() among others. Such routines are
themselves implemented in terms of set_ptes_at().

A future patch providing support for page table checking on powerpc must
take care to avoid duplicate calls to page_table_check_p{te,md,ud}_set().
Allow for assignment of pte entries without instrumentation through the
set_pte_at_unchecked() routine introduced in this patch.

Cause API-facing routines that call set_pte_at() to instead call
set_pte_at_unchecked(), which will remain uninstrumented by page table
check. set_ptes() is itself implemented by calls to __set_pte_at(), so
this eliminates redundant code.

[ajd@linux.ibm.com: don't change to unchecked for early boot/kernel mappings]
Link: https://lkml.kernel.org/r/20251219-pgtable_check_v18rebase-v18-11-755bc151a50b@linux.ibm.com
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Guo Weikang <guoweikang.kernel@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Magnus Lindholm <linmag7@gmail.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Cc: Thomas Huth <thuth@redhat.com>
Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

authored by

Rohan McLure and committed by
Andrew Morton 2360f523 2f5e5765

+16 -6
+2
arch/powerpc/include/asm/pgtable.h
··· 34 34 void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep, 35 35 pte_t pte, unsigned int nr); 36 36 #define set_ptes set_ptes 37 + void set_pte_at_unchecked(struct mm_struct *mm, unsigned long addr, 38 + pte_t *ptep, pte_t pte); 37 39 #define update_mmu_cache(vma, addr, ptep) \ 38 40 update_mmu_cache_range(NULL, vma, addr, ptep, 1) 39 41
+3 -3
arch/powerpc/mm/book3s64/pgtable.c
··· 127 127 WARN_ON(!(pmd_leaf(pmd))); 128 128 #endif 129 129 trace_hugepage_set_pmd(addr, pmd_val(pmd)); 130 - return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd)); 130 + return set_pte_at_unchecked(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd)); 131 131 } 132 132 133 133 void set_pud_at(struct mm_struct *mm, unsigned long addr, ··· 144 144 WARN_ON(!(pud_leaf(pud))); 145 145 #endif 146 146 trace_hugepage_set_pud(addr, pud_val(pud)); 147 - return set_pte_at(mm, addr, pudp_ptep(pudp), pud_pte(pud)); 147 + return set_pte_at_unchecked(mm, addr, pudp_ptep(pudp), pud_pte(pud)); 148 148 } 149 149 150 150 static void do_serialize(void *arg) ··· 550 550 if (radix_enabled()) 551 551 return radix__ptep_modify_prot_commit(vma, addr, 552 552 ptep, old_pte, pte); 553 - set_pte_at(vma->vm_mm, addr, ptep, pte); 553 + set_pte_at_unchecked(vma->vm_mm, addr, ptep, pte); 554 554 } 555 555 556 556 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
+3 -3
arch/powerpc/mm/book3s64/radix_pgtable.c
··· 1606 1606 (atomic_read(&mm->context.copros) > 0)) 1607 1607 radix__flush_tlb_page(vma, addr); 1608 1608 1609 - set_pte_at(mm, addr, ptep, pte); 1609 + set_pte_at_unchecked(mm, addr, ptep, pte); 1610 1610 } 1611 1611 1612 1612 int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) ··· 1617 1617 if (!radix_enabled()) 1618 1618 return 0; 1619 1619 1620 - set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pud); 1620 + set_pte_at_unchecked(&init_mm, 0 /* radix unused */, ptep, new_pud); 1621 1621 1622 1622 return 1; 1623 1623 } ··· 1664 1664 if (!radix_enabled()) 1665 1665 return 0; 1666 1666 1667 - set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pmd); 1667 + set_pte_at_unchecked(&init_mm, 0 /* radix unused */, ptep, new_pmd); 1668 1668 1669 1669 return 1; 1670 1670 }
+8
arch/powerpc/mm/pgtable.c
··· 224 224 } 225 225 } 226 226 227 + void set_pte_at_unchecked(struct mm_struct *mm, unsigned long addr, 228 + pte_t *ptep, pte_t pte) 229 + { 230 + VM_WARN_ON(pte_hw_valid(*ptep) && !pte_protnone(*ptep)); 231 + pte = set_pte_filter(pte, addr); 232 + __set_pte_at(mm, addr, ptep, pte, 0); 233 + } 234 + 227 235 void unmap_kernel_page(unsigned long va) 228 236 { 229 237 pmd_t *pmdp = pmd_off_k(va);