1 /* 2 * Copyright (c) 1990 University of Utah. 3 * Copyright (c) 1991 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * %sccs.include.redist.c% 11 * 12 * @(#)vm_pager.h 7.2 (Berkeley) 04/20/91 13 */ 14 15 /* 16 * Pager routine interface definition. 17 * For BSD we use a cleaner version of the internal pager interface. 18 */ 19 20 #ifndef _VM_PAGER_ 21 #define _VM_PAGER_ 22 23 struct pager_struct { 24 queue_head_t pg_list; /* links for list management */ 25 caddr_t pg_handle; /* external handle (vp, dev, fp) */ 26 int pg_type; /* type of pager */ 27 struct pagerops *pg_ops; /* pager operations */ 28 caddr_t pg_data; /* private pager data */ 29 }; 30 typedef struct pager_struct *vm_pager_t; 31 32 /* pager types */ 33 #define PG_DFLT -1 34 #define PG_SWAP 0 35 #define PG_VNODE 1 36 #define PG_DEVICE 2 37 38 struct pagerops { 39 void (*pgo_init)(); /* initialize pager */ 40 vm_pager_t (*pgo_alloc)(); /* allocate pager */ 41 void (*pgo_dealloc)(); /* disassociate */ 42 int (*pgo_getpage)(); /* get (read) page */ 43 int (*pgo_putpage)(); /* put (write) page */ 44 boolean_t (*pgo_haspage)(); /* does pager have page? */ 45 }; 46 47 /* 48 * get/put return values 49 * OK operation was successful 50 * BAD specified data was out of the accepted range 51 * FAIL specified data was in range, but doesn't exist 52 * PEND operations was initiated but not completed 53 */ 54 #define VM_PAGER_OK 0 55 #define VM_PAGER_BAD 1 56 #define VM_PAGER_FAIL 2 57 #define VM_PAGER_PEND 3 58 59 #define VM_PAGER_ALLOC(h, s, p) (*(pg)->pg_ops->pgo_alloc)(h, s, p) 60 #define VM_PAGER_DEALLOC(pg) (*(pg)->pg_ops->pgo_dealloc)(pg) 61 #define VM_PAGER_GET(pg, m, s) (*(pg)->pg_ops->pgo_getpage)(pg, m, s) 62 #define VM_PAGER_PUT(pg, m, s) (*(pg)->pg_ops->pgo_putpage)(pg, m, s) 63 #define VM_PAGER_HASPAGE(pg, o) (*(pg)->pg_ops->pgo_haspage)(pg, o) 64 65 #ifdef KERNEL 66 vm_pager_t vm_pager_allocate(); 67 void vm_pager_deallocate(); 68 int vm_pager_get(); 69 int vm_pager_put(); 70 boolean_t vm_pager_has_page(); 71 72 vm_offset_t vm_pager_map_page(); 73 void vm_pager_unmap_page(); 74 vm_pager_t vm_pager_lookup(); 75 void vm_pager_sync(); 76 77 extern struct pagerops *dfltpagerops; 78 #endif 79 80 #endif /* _VM_PAGER_ */ 81