uvm_page_array.h revision 1.3 1 1.3 ad /* $NetBSD: uvm_page_array.h,v 1.3 2020/05/25 21:15:10 ad Exp $ */
2 1.2 ad
3 1.2 ad /*-
4 1.2 ad * Copyright (c)2011 YAMAMOTO Takashi,
5 1.2 ad * All rights reserved.
6 1.2 ad *
7 1.2 ad * Redistribution and use in source and binary forms, with or without
8 1.2 ad * modification, are permitted provided that the following conditions
9 1.2 ad * are met:
10 1.2 ad * 1. Redistributions of source code must retain the above copyright
11 1.2 ad * notice, this list of conditions and the following disclaimer.
12 1.2 ad * 2. Redistributions in binary form must reproduce the above copyright
13 1.2 ad * notice, this list of conditions and the following disclaimer in the
14 1.2 ad * documentation and/or other materials provided with the distribution.
15 1.2 ad *
16 1.2 ad * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 1.2 ad * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 1.2 ad * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 1.2 ad * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 1.2 ad * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 1.2 ad * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 1.2 ad * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 1.2 ad * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 1.2 ad * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 1.2 ad * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 1.2 ad * SUCH DAMAGE.
27 1.2 ad */
28 1.2 ad
29 1.2 ad #if !defined(_UVM_UVM_PAGE_ARRAY_H_)
30 1.2 ad #define _UVM_UVM_PAGE_ARRAY_H_
31 1.2 ad
32 1.2 ad /*
33 1.2 ad * uvm_page_array: an array of pages.
34 1.2 ad *
35 1.2 ad * these structure and functions simply manipulate struct vm_page pointers.
36 1.2 ad * it's caller's responsibity to acquire and keep the object lock so that
37 1.2 ad * the result is valid.
38 1.2 ad *
39 1.2 ad * typical usage:
40 1.2 ad *
41 1.2 ad * struct uvm_page_array a;
42 1.2 ad *
43 1.3 ad * uvm_page_array_init(&a, uobj, ...);
44 1.3 ad * while ((pg = uvm_page_array_fill_and_peek(&a, off, 0)) != NULL) {
45 1.2 ad * off = pg->offset + PAGE_SIZE;
46 1.2 ad * do_something(pg);
47 1.2 ad * uvm_page_array_advance(&a);
48 1.2 ad * }
49 1.2 ad * uvm_page_array_fini(&a);
50 1.3 ad *
51 1.3 ad * if scanning forwards the "off" argument may not go backwards.
52 1.3 ad * if scanning backwards, the "off" argument may not go forwards.
53 1.2 ad */
54 1.2 ad
55 1.2 ad struct vm_page;
56 1.2 ad
57 1.2 ad struct uvm_page_array {
58 1.2 ad unsigned int ar_npages; /* valid elements in ar_pages */
59 1.2 ad unsigned int ar_idx; /* index in ar_pages */
60 1.3 ad struct uvm_object *ar_uobj;
61 1.3 ad unsigned int ar_flags;
62 1.3 ad voff_t ar_lastoff;
63 1.3 ad struct vm_page *ar_pages[16]; /* XXX tune */
64 1.2 ad };
65 1.2 ad
66 1.3 ad void uvm_page_array_init(struct uvm_page_array *, struct uvm_object *,
67 1.3 ad unsigned int);
68 1.2 ad void uvm_page_array_fini(struct uvm_page_array *);
69 1.2 ad void uvm_page_array_clear(struct uvm_page_array *);
70 1.2 ad struct vm_page *uvm_page_array_peek(struct uvm_page_array *);
71 1.2 ad void uvm_page_array_advance(struct uvm_page_array *);
72 1.3 ad int uvm_page_array_fill(struct uvm_page_array *, voff_t, unsigned int);
73 1.2 ad struct vm_page *uvm_page_array_fill_and_peek(struct uvm_page_array *,
74 1.3 ad voff_t, unsigned int);
75 1.2 ad
76 1.2 ad /*
77 1.2 ad * flags for uvm_page_array_fill and uvm_page_array_fill_and_peek
78 1.2 ad */
79 1.2 ad #define UVM_PAGE_ARRAY_FILL_DIRTY 1 /* dirty pages */
80 1.2 ad #define UVM_PAGE_ARRAY_FILL_WRITEBACK 2 /* dirty or written-back */
81 1.2 ad #define UVM_PAGE_ARRAY_FILL_DENSE 4 /* stop on a hole */
82 1.2 ad #define UVM_PAGE_ARRAY_FILL_BACKWARD 8 /* descend order */
83 1.2 ad
84 1.2 ad #endif /* defined(_UVM_UVM_ARRAY_H_) */
85