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1 : /* $OpenBSD: uvm_pmemrange.h,v 1.14 2016/09/16 02:47:09 dlg Exp $ */
2 :
3 : /*
4 : * Copyright (c) 2009 Ariane van der Steldt <ariane@stack.nl>
5 : *
6 : * Permission to use, copy, modify, and distribute this software for any
7 : * purpose with or without fee is hereby granted, provided that the above
8 : * copyright notice and this permission notice appear in all copies.
9 : *
10 : * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 : * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 : * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 : * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 : * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 : * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 : * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 : */
18 :
19 : /*
20 : * uvm_pmemrange.h: describe and manage free physical memory.
21 : */
22 :
23 : #ifndef _UVM_UVM_PMEMRANGE_H_
24 : #define _UVM_UVM_PMEMRANGE_H_
25 :
26 : RBT_HEAD(uvm_pmr_addr, vm_page);
27 : RBT_HEAD(uvm_pmr_size, vm_page);
28 :
29 : /*
30 : * Page types available:
31 : * - DIRTY: this page may contain random data.
32 : * - ZERO: this page has been zeroed.
33 : */
34 : #define UVM_PMR_MEMTYPE_DIRTY 0
35 : #define UVM_PMR_MEMTYPE_ZERO 1
36 : #define UVM_PMR_MEMTYPE_MAX 2
37 :
38 : /*
39 : * An address range of memory.
40 : */
41 : struct uvm_pmemrange {
42 : struct uvm_pmr_addr addr; /* Free page chunks, sorted by addr. */
43 : struct uvm_pmr_size size[UVM_PMR_MEMTYPE_MAX];
44 : /* Free page chunks, sorted by size. */
45 : TAILQ_HEAD(, vm_page) single[UVM_PMR_MEMTYPE_MAX];
46 : /* single page regions (uses pageq) */
47 :
48 : paddr_t low; /* Start of address range (pgno). */
49 : paddr_t high; /* End +1 (pgno). */
50 : int use; /* Use counter. */
51 : psize_t nsegs; /* Current range count. */
52 :
53 : TAILQ_ENTRY(uvm_pmemrange) pmr_use;
54 : /* pmr, sorted by use */
55 : RBT_ENTRY(uvm_pmemrange) pmr_addr;
56 : /* pmr, sorted by address */
57 : };
58 :
59 : /*
60 : * Description of failing memory allocation.
61 : *
62 : * Two ways new pages can become available:
63 : * [1] page daemon drops them (we notice because they are freed)
64 : * [2] a process calls free
65 : *
66 : * The buffer cache and page daemon can decide that they don't have the
67 : * ability to make pages available in the requested range. In that case,
68 : * the FAIL bit will be set.
69 : * XXX There's a possibility that a page is no longer on the queues but
70 : * XXX has not yet been freed, or that a page was busy.
71 : * XXX Also, wired pages are not considered for paging, so they could
72 : * XXX cause a failure that may be recoverable.
73 : */
74 : struct uvm_pmalloc {
75 : TAILQ_ENTRY(uvm_pmalloc) pmq;
76 :
77 : /*
78 : * Allocation request parameters.
79 : */
80 : struct uvm_constraint_range pm_constraint;
81 : psize_t pm_size;
82 :
83 : /*
84 : * State flags.
85 : */
86 : int pm_flags;
87 : };
88 :
89 : /*
90 : * uvm_pmalloc flags.
91 : */
92 : #define UVM_PMA_LINKED 0x01 /* uvm_pmalloc is on list */
93 : #define UVM_PMA_BUSY 0x02 /* entry is busy with fpageq unlocked */
94 : #define UVM_PMA_FAIL 0x10 /* page daemon cannot free pages */
95 : #define UVM_PMA_FREED 0x20 /* at least one page in the range was freed */
96 :
97 : RBT_HEAD(uvm_pmemrange_addr, uvm_pmemrange);
98 : TAILQ_HEAD(uvm_pmemrange_use, uvm_pmemrange);
99 :
100 : /*
101 : * pmr control structure. Contained in uvm.pmr_control.
102 : */
103 : struct uvm_pmr_control {
104 : struct uvm_pmemrange_addr addr;
105 : struct uvm_pmemrange_use use;
106 :
107 : /* Only changed while fpageq is locked. */
108 : TAILQ_HEAD(, uvm_pmalloc) allocs;
109 : };
110 :
111 : void uvm_pmr_freepages(struct vm_page *, psize_t);
112 : void uvm_pmr_freepageq(struct pglist *);
113 : int uvm_pmr_getpages(psize_t, paddr_t, paddr_t, paddr_t, paddr_t,
114 : int, int, struct pglist *);
115 : void uvm_pmr_init(void);
116 : int uvm_wait_pla(paddr_t, paddr_t, paddr_t, int);
117 : void uvm_wakeup_pla(paddr_t, psize_t);
118 :
119 : #if defined(DDB) || defined(DEBUG)
120 : int uvm_pmr_isfree(struct vm_page *pg);
121 : #endif
122 :
123 : /*
124 : * Internal tree logic.
125 : */
126 :
127 : int uvm_pmr_addr_cmp(const struct vm_page *, const struct vm_page *);
128 : int uvm_pmr_size_cmp(const struct vm_page *, const struct vm_page *);
129 :
130 0 : RBT_PROTOTYPE(uvm_pmr_addr, vm_page, objt, uvm_pmr_addr_cmp);
131 0 : RBT_PROTOTYPE(uvm_pmr_size, vm_page, objt, uvm_pmr_size_cmp);
132 0 : RBT_PROTOTYPE(uvm_pmemrange_addr, uvm_pmemrange, pmr_addr,
133 : uvm_pmemrange_addr_cmp);
134 :
135 : struct vm_page *uvm_pmr_insert_addr(struct uvm_pmemrange *,
136 : struct vm_page *, int);
137 : void uvm_pmr_insert_size(struct uvm_pmemrange *,
138 : struct vm_page *);
139 : struct vm_page *uvm_pmr_insert(struct uvm_pmemrange *,
140 : struct vm_page *, int);
141 : void uvm_pmr_remove_addr(struct uvm_pmemrange *,
142 : struct vm_page *);
143 : void uvm_pmr_remove_size(struct uvm_pmemrange *,
144 : struct vm_page *);
145 : void uvm_pmr_remove(struct uvm_pmemrange *,
146 : struct vm_page *);
147 : struct vm_page *uvm_pmr_extract_range(struct uvm_pmemrange *,
148 : struct vm_page *, paddr_t, paddr_t,
149 : struct pglist *);
150 :
151 : #endif /* _UVM_UVM_PMEMRANGE_H_ */
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