[PATCH v2 04/22] mm: Create flags arg for __apply_to_page_range()

[Brendan Jackman <jackmanb@google.com>]

Preparatory patch, no functional change intended.

To prepare for making this function more generic, convert the boolean
"create" arg into a flags arg with a single flag that has the same
meaning.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
---
 mm/internal.h | 10 ++++++++++
 mm/memory.c   | 29 +++++++++++++++++------------
 2 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/mm/internal.h b/mm/internal.h
index f98f4746ac412..4b389431b1639 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1870,4 +1870,14 @@ static inline int get_sysctl_max_map_count(void)
 	return READ_ONCE(sysctl_max_map_count);
 }
 
+/*
+ * Create a mapping if it doesn't exist. (Otherwise, skip regions with no
+ * existing mapping, and return an error for regions with no leaf pagetable).
+ */
+#define PGRANGE_CREATE		(1 << 0)
+
+int __apply_to_page_range(struct mm_struct *mm, unsigned long addr,
+			  unsigned long size, pte_fn_t fn,
+			  void *data, unsigned int flags);
+
 #endif	/* __MM_INTERNAL_H */
diff --git a/mm/memory.c b/mm/memory.c
index 219b9bf6cae00..7e55014e5560b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3208,9 +3208,10 @@ EXPORT_SYMBOL(vm_iomap_memory);
 
 static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
 				     unsigned long addr, unsigned long end,
-				     pte_fn_t fn, void *data, bool create,
+				     pte_fn_t fn, void *data, unsigned int flags,
 				     pgtbl_mod_mask *mask)
 {
+	bool create = flags & PGRANGE_CREATE;
 	pte_t *pte, *mapped_pte;
 	int err = 0;
 	spinlock_t *ptl;
@@ -3251,10 +3252,11 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
 
 static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud,
 				     unsigned long addr, unsigned long end,
-				     pte_fn_t fn, void *data, bool create,
+				     pte_fn_t fn, void *data, unsigned int flags,
 				     pgtbl_mod_mask *mask)
 {
 	pmd_t *pmd;
+	bool create = flags & PGRANGE_CREATE;
 	unsigned long next;
 	int err = 0;
 
@@ -3279,7 +3281,7 @@ static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud,
 			pmd_clear_bad(pmd);
 		}
 		err = apply_to_pte_range(mm, pmd, addr, next,
-					 fn, data, create, mask);
+					 fn, data, flags, mask);
 		if (err)
 			break;
 	} while (pmd++, addr = next, addr != end);
@@ -3289,10 +3291,11 @@ static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud,
 
 static int apply_to_pud_range(struct mm_struct *mm, p4d_t *p4d,
 				     unsigned long addr, unsigned long end,
-				     pte_fn_t fn, void *data, bool create,
+				     pte_fn_t fn, void *data, unsigned int flags,
 				     pgtbl_mod_mask *mask)
 {
 	pud_t *pud;
+	bool create = flags & PGRANGE_CREATE;
 	unsigned long next;
 	int err = 0;
 
@@ -3325,10 +3328,11 @@ static int apply_to_pud_range(struct mm_struct *mm, p4d_t *p4d,
 
 static int apply_to_p4d_range(struct mm_struct *mm, pgd_t *pgd,
 				     unsigned long addr, unsigned long end,
-				     pte_fn_t fn, void *data, bool create,
+				     pte_fn_t fn, void *data, unsigned int flags,
 				     pgtbl_mod_mask *mask)
 {
 	p4d_t *p4d;
+	bool create = flags & PGRANGE_CREATE;
 	unsigned long next;
 	int err = 0;
 
@@ -3351,7 +3355,7 @@ static int apply_to_p4d_range(struct mm_struct *mm, pgd_t *pgd,
 			p4d_clear_bad(p4d);
 		}
 		err = apply_to_pud_range(mm, p4d, addr, next,
-					 fn, data, create, mask);
+					 fn, data, flags, mask);
 		if (err)
 			break;
 	} while (p4d++, addr = next, addr != end);
@@ -3359,11 +3363,12 @@ static int apply_to_p4d_range(struct mm_struct *mm, pgd_t *pgd,
 	return err;
 }
 
-static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr,
-				 unsigned long size, pte_fn_t fn,
-				 void *data, bool create)
+int __apply_to_page_range(struct mm_struct *mm, unsigned long addr,
+			  unsigned long size, pte_fn_t fn,
+			  void *data, unsigned int flags)
 {
 	pgd_t *pgd;
+	bool create = flags & PGRANGE_CREATE;
 	unsigned long start = addr, next;
 	unsigned long end = addr + size;
 	pgtbl_mod_mask mask = 0;
@@ -3387,7 +3392,7 @@ static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr,
 			pgd_clear_bad(pgd);
 		}
 		err = apply_to_p4d_range(mm, pgd, addr, next,
-					 fn, data, create, &mask);
+					 fn, data, flags, &mask);
 		if (err)
 			break;
 	} while (pgd++, addr = next, addr != end);
@@ -3405,7 +3410,7 @@ static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr,
 int apply_to_page_range(struct mm_struct *mm, unsigned long addr,
 			unsigned long size, pte_fn_t fn, void *data)
 {
-	return __apply_to_page_range(mm, addr, size, fn, data, true);
+	return __apply_to_page_range(mm, addr, size, fn, data, PGRANGE_CREATE);
 }
 EXPORT_SYMBOL_GPL(apply_to_page_range);
 
@@ -3419,7 +3424,7 @@ EXPORT_SYMBOL_GPL(apply_to_page_range);
 int apply_to_existing_page_range(struct mm_struct *mm, unsigned long addr,
 				 unsigned long size, pte_fn_t fn, void *data)
 {
-	return __apply_to_page_range(mm, addr, size, fn, data, false);
+	return __apply_to_page_range(mm, addr, size, fn, data, 0);
 }
 
 /*

-- 
2.51.2