diff options
Diffstat (limited to 'mm/internal.h')
| -rw-r--r-- | mm/internal.h | 43 |
1 files changed, 39 insertions, 4 deletions
diff --git a/mm/internal.h b/mm/internal.h index aa30282a774ae..06f816cdb43bd 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -25,6 +25,44 @@ struct folio_batch; /* + * Maintains state across a page table move. The operation assumes both source + * and destination VMAs already exist and are specified by the user. + * + * Partial moves are permitted, but the old and new ranges must both reside + * within a VMA. + * + * mmap lock must be held in write and VMA write locks must be held on any VMA + * that is visible. + * + * Use the PAGETABLE_MOVE() macro to initialise this struct. + * + * NOTE: The page table move is affected by reading from [old_addr, old_end), + * and old_addr may be updated for better page table alignment, so len_in + * represents the length of the range being copied as specified by the user. + */ +struct pagetable_move_control { + struct vm_area_struct *old; /* Source VMA. */ + struct vm_area_struct *new; /* Destination VMA. */ + unsigned long old_addr; /* Address from which the move begins. */ + unsigned long old_end; /* Exclusive address at which old range ends. */ + unsigned long new_addr; /* Address to move page tables to. */ + unsigned long len_in; /* Bytes to remap specified by user. */ + + bool need_rmap_locks; /* Do rmap locks need to be taken? */ + bool for_stack; /* Is this an early temp stack being moved? */ +}; + +#define PAGETABLE_MOVE(name, old_, new_, old_addr_, new_addr_, len_) \ + struct pagetable_move_control name = { \ + .old = old_, \ + .new = new_, \ + .old_addr = old_addr_, \ + .old_end = (old_addr_) + (len_), \ + .new_addr = new_addr_, \ + .len_in = len_, \ + } + +/* * The set of flags that only affect watermark checking and reclaim * behaviour. This is used by the MM to obey the caller constraints * about IO, FS and watermark checking while ignoring placement @@ -1527,10 +1565,7 @@ extern struct list_lru shadow_nodes; } while (0) /* mremap.c */ -unsigned long move_page_tables(struct vm_area_struct *vma, - unsigned long old_addr, struct vm_area_struct *new_vma, - unsigned long new_addr, unsigned long len, - bool need_rmap_locks, bool for_stack); +unsigned long move_page_tables(struct pagetable_move_control *pmc); #ifdef CONFIG_UNACCEPTED_MEMORY void accept_page(struct page *page); |