pagewalk: separate function pointers from iterator data

The mm_walk structure currently mixed data and code.  Split out the
operations vectors into a new mm_walk_ops structure, and while we are
changing the API also declare the mm_walk structure inside the
walk_page_range and walk_page_vma functions.

Based on patch from Linus Torvalds.

Link: https://lore.kernel.org/r/20190828141955.22210-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 15 insertions, 18 deletions

diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index cf80feae970d..bd78d504fdad 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -2521,13 +2521,9 @@ static int __zap_zero_pages(pmd_t *pmd, unsigned long start,
         return 0;
 }
 
-static inline void zap_zero_pages(struct mm_struct *mm)
-{
-        struct mm_walk walk = { .pmd_entry = __zap_zero_pages };
-
-        walk.mm = mm;
-        walk_page_range(0, TASK_SIZE, &walk);
-}
+static const struct mm_walk_ops zap_zero_walk_ops = {
+        .pmd_entry      = __zap_zero_pages,
+};
 
 /*
  * switch on pgstes for its userspace process (for kvm)
@@ -2546,7 +2542,7 @@ int s390_enable_sie(void)
         mm->context.has_pgste = 1;
         /* split thp mappings and disable thp for future mappings */
         thp_split_mm(mm);
-        zap_zero_pages(mm);
+        walk_page_range(mm, 0, TASK_SIZE, &zap_zero_walk_ops, NULL);
         up_write(&mm->mmap_sem);
         return 0;
 }
@@ -2589,12 +2585,13 @@ static int __s390_enable_skey_hugetlb(pte_t *pte, unsigned long addr,
         return 0;
 }
 
+static const struct mm_walk_ops enable_skey_walk_ops = {
+        .hugetlb_entry          = __s390_enable_skey_hugetlb,
+        .pte_entry              = __s390_enable_skey_pte,
+};
+
 int s390_enable_skey(void)
 {
-        struct mm_walk walk = {
-                .hugetlb_entry = __s390_enable_skey_hugetlb,
-                .pte_entry = __s390_enable_skey_pte,
-        };
         struct mm_struct *mm = current->mm;
         struct vm_area_struct *vma;
         int rc = 0;
@@ -2614,8 +2611,7 @@ int s390_enable_skey(void)
         }
         mm->def_flags &= ~VM_MERGEABLE;
 
-        walk.mm = mm;
-        walk_page_range(0, TASK_SIZE, &walk);
+        walk_page_range(mm, 0, TASK_SIZE, &enable_skey_walk_ops, NULL);
 
 out_up:
         up_write(&mm->mmap_sem);
@@ -2633,13 +2629,14 @@ static int __s390_reset_cmma(pte_t *pte, unsigned long addr,
         return 0;
 }
 
+static const struct mm_walk_ops reset_cmma_walk_ops = {
+        .pte_entry              = __s390_reset_cmma,
+};
+
 void s390_reset_cmma(struct mm_struct *mm)
 {
-        struct mm_walk walk = { .pte_entry = __s390_reset_cmma };
-
         down_write(&mm->mmap_sem);
-        walk.mm = mm;
-        walk_page_range(0, TASK_SIZE, &walk);
+        walk_page_range(mm, 0, TASK_SIZE, &reset_cmma_walk_ops, NULL);
         up_write(&mm->mmap_sem);
 }
 EXPORT_SYMBOL_GPL(s390_reset_cmma);