[PATCH v9 6/7] powerpc: mm: Use __set_pte_at() for early-boot / internal usages

[Rohan McLure]

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().

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

Also prefer __set_pte_at() in early-boot usages which should not be
instrumented.

Signed-off-by: Rohan McLure <rmclure at linux.ibm.com>
---
v9: New patch
---
 arch/powerpc/mm/book3s64/hash_pgtable.c  |  2 +-
 arch/powerpc/mm/book3s64/pgtable.c       |  4 ++--
 arch/powerpc/mm/book3s64/radix_pgtable.c | 10 +++++-----
 arch/powerpc/mm/nohash/book3e_pgtable.c  |  2 +-
 arch/powerpc/mm/pgtable_32.c             |  2 +-
 5 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/mm/book3s64/hash_pgtable.c b/arch/powerpc/mm/book3s64/hash_pgtable.c
index 988948d69bc1..ae52c8db45b7 100644
--- a/arch/powerpc/mm/book3s64/hash_pgtable.c
+++ b/arch/powerpc/mm/book3s64/hash_pgtable.c
@@ -165,7 +165,7 @@ int hash__map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t prot)
 		ptep = pte_alloc_kernel(pmdp, ea);
 		if (!ptep)
 			return -ENOMEM;
-		set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot));
+		__set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot), 0);
 	} else {
 		/*
 		 * If the mm subsystem is not fully up, we cannot create a
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index be229290a6a7..9a0a2accb261 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -116,7 +116,7 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 	WARN_ON(!(pmd_large(pmd)));
 #endif
 	trace_hugepage_set_pmd(addr, pmd_val(pmd));
-	return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
+	return __set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd), 0);
 }
 
 void set_pud_at(struct mm_struct *mm, unsigned long addr,
@@ -539,7 +539,7 @@ void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
 	if (radix_enabled())
 		return radix__ptep_modify_prot_commit(vma, addr,
 						      ptep, old_pte, pte);
-	set_pte_at(vma->vm_mm, addr, ptep, pte);
+	__set_pte_at(vma->vm_mm, addr, ptep, pte, 0);
 }
 
 /*
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 1f8db10693e3..ae4a5f66ccd2 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -109,7 +109,7 @@ static int early_map_kernel_page(unsigned long ea, unsigned long pa,
 	ptep = pte_offset_kernel(pmdp, ea);
 
 set_the_pte:
-	set_pte_at(&init_mm, ea, ptep, pfn_pte(pfn, flags));
+	__set_pte_at(&init_mm, ea, ptep, pfn_pte(pfn, flags), 0);
 	asm volatile("ptesync": : :"memory");
 	return 0;
 }
@@ -169,7 +169,7 @@ static int __map_kernel_page(unsigned long ea, unsigned long pa,
 		return -ENOMEM;
 
 set_the_pte:
-	set_pte_at(&init_mm, ea, ptep, pfn_pte(pfn, flags));
+	__set_pte_at(&init_mm, ea, ptep, pfn_pte(pfn, flags), 0);
 	asm volatile("ptesync": : :"memory");
 	return 0;
 }
@@ -1536,7 +1536,7 @@ void radix__ptep_modify_prot_commit(struct vm_area_struct *vma,
 	    (atomic_read(&mm->context.copros) > 0))
 		radix__flush_tlb_page(vma, addr);
 
-	set_pte_at(mm, addr, ptep, pte);
+	__set_pte_at(mm, addr, ptep, pte, 0);
 }
 
 int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
@@ -1547,7 +1547,7 @@ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
 	if (!radix_enabled())
 		return 0;
 
-	set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pud);
+	__set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pud, 0);
 
 	return 1;
 }
@@ -1594,7 +1594,7 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
 	if (!radix_enabled())
 		return 0;
 
-	set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pmd);
+	__set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pmd, 0);
 
 	return 1;
 }
diff --git a/arch/powerpc/mm/nohash/book3e_pgtable.c b/arch/powerpc/mm/nohash/book3e_pgtable.c
index 1c5e4ecbebeb..4de91b54fd89 100644
--- a/arch/powerpc/mm/nohash/book3e_pgtable.c
+++ b/arch/powerpc/mm/nohash/book3e_pgtable.c
@@ -111,7 +111,7 @@ int __ref map_kernel_page(unsigned long ea, phys_addr_t pa, pgprot_t prot)
 		}
 		ptep = pte_offset_kernel(pmdp, ea);
 	}
-	set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot));
+	__set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot), 0);
 
 	smp_wmb();
 	return 0;
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index 5c02fd08d61e..4bf3ca6af7cd 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -89,7 +89,7 @@ int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot)
 		 * hash table
 		 */
 		BUG_ON((pte_present(*pg) | pte_hashpte(*pg)) && pgprot_val(prot));
-		set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot));
+		__set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot), 0);
 	}
 	smp_wmb();
 	return err;
-- 
2.43.0