mm: Add a walk_page_mapping() function to the pagewalk code

For users that want to travers all page table entries pointing into a
region of a struct address_space mapping, introduce a walk_page_mapping()
function.

The walk_page_mapping() function will be initially be used for dirty-
tracking in virtual graphics drivers.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Thomas Hellstrom
2019-10-01 11:17:34 +02:00
parent ace88f1018
commit ecaad8aca2
2 changed files with 102 additions and 1 deletions

View File

@@ -24,6 +24,9 @@ struct mm_walk;
* "do page table walk over the current vma", returning
* a negative value means "abort current page table walk
* right now" and returning 1 means "skip the current vma"
* @pre_vma: if set, called before starting walk on a non-null vma.
* @post_vma: if set, called after a walk on a non-null vma, provided
* that @pre_vma and the vma walk succeeded.
*/
struct mm_walk_ops {
int (*pud_entry)(pud_t *pud, unsigned long addr,
@@ -39,6 +42,9 @@ struct mm_walk_ops {
struct mm_walk *walk);
int (*test_walk)(unsigned long addr, unsigned long next,
struct mm_walk *walk);
int (*pre_vma)(unsigned long start, unsigned long end,
struct mm_walk *walk);
void (*post_vma)(struct mm_walk *walk);
};
/**
@@ -62,5 +68,8 @@ int walk_page_range(struct mm_struct *mm, unsigned long start,
void *private);
int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops,
void *private);
int walk_page_mapping(struct address_space *mapping, pgoff_t first_index,
pgoff_t nr, const struct mm_walk_ops *ops,
void *private);
#endif /* _LINUX_PAGEWALK_H */