FreeBSD/Linux Kernel Cross Reference
sys/sys/sf_buf.h
1 /*-
2 * Copyright (c) 2014 Gleb Smirnoff <glebius@FreeBSD.org>
3 * Copyright (c) 2003-2004 Alan L. Cox <alc@cs.rice.edu>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD: releng/11.2/sys/sys/sf_buf.h 331722 2018-03-29 02:50:57Z eadler $
28 */
29
30 #ifndef _SYS_SF_BUF_H_
31 #define _SYS_SF_BUF_H_
32
33 struct sfstat { /* sendfile statistics */
34 uint64_t sf_syscalls; /* times sendfile was called */
35 uint64_t sf_noiocnt; /* times sendfile didn't require I/O */
36 uint64_t sf_iocnt; /* times sendfile had to do disk I/O */
37 uint64_t sf_pages_read; /* pages read as part of a request */
38 uint64_t sf_pages_valid; /* pages were valid for a request */
39 uint64_t sf_rhpages_requested; /* readahead pages requested */
40 uint64_t sf_rhpages_read; /* readahead pages read */
41 uint64_t sf_busy; /* times aborted on a busy page */
42 uint64_t sf_allocfail; /* times sfbuf allocation failed */
43 uint64_t sf_allocwait; /* times sfbuf allocation had to wait */
44 };
45
46 #ifdef _KERNEL
47 #include <sys/types.h>
48 #include <sys/systm.h>
49 #include <sys/counter.h>
50 #include <vm/vm.h>
51 #include <vm/vm_param.h>
52 #include <vm/vm_page.h>
53
54 /*
55 * Sf_bufs, or sendfile(2) buffers provide a vm_page that is mapped
56 * into kernel address space. Note, that they aren't used only
57 * by sendfile(2)!
58 *
59 * Sf_bufs could be implemented as a feature of vm_page_t, but that
60 * would require growth of the structure. That's why they are implemented
61 * as a separate hash indexed by vm_page address. Implementation lives in
62 * kern/subr_sfbuf.c. Meanwhile, most 64-bit machines have a physical map,
63 * so they don't require this hash at all, thus ignore subr_sfbuf.c.
64 *
65 * Different 32-bit architectures demand different requirements on sf_buf
66 * hash and functions. They request features in machine/vmparam.h, which
67 * enable parts of this file. They can also optionally provide helpers in
68 * machine/sf_buf.h
69 *
70 * Defines are:
71 * SFBUF This machine requires sf_buf hash.
72 * subr_sfbuf.c should be compiled.
73 * SFBUF_CPUSET This machine can perform SFB_CPUPRIVATE mappings,
74 * that do no invalidate cache on the rest of CPUs.
75 * SFBUF_NOMD This machine doesn't have machine/sf_buf.h
76 *
77 * SFBUF_OPTIONAL_DIRECT_MAP Value of this define is used as boolean
78 * variable that tells whether machine is
79 * capable of direct map or not at runtime.
80 * SFBUF_MAP This machine provides its own sf_buf_map() and
81 * sf_buf_unmap().
82 * SFBUF_PROCESS_PAGE This machine provides sf_buf_process_page()
83 * function.
84 */
85
86 #ifdef SFBUF
87 #if defined(SMP) && defined(SFBUF_CPUSET)
88 #include <sys/_cpuset.h>
89 #endif
90 #include <sys/queue.h>
91
92 struct sf_buf {
93 LIST_ENTRY(sf_buf) list_entry; /* list of buffers */
94 TAILQ_ENTRY(sf_buf) free_entry; /* list of buffers */
95 vm_page_t m; /* currently mapped page */
96 vm_offset_t kva; /* va of mapping */
97 int ref_count; /* usage of this mapping */
98 #if defined(SMP) && defined(SFBUF_CPUSET)
99 cpuset_t cpumask; /* where mapping is valid */
100 #endif
101 };
102 #else /* ! SFBUF */
103 struct sf_buf;
104 #endif /* SFBUF */
105
106 #ifndef SFBUF_NOMD
107 #include <machine/sf_buf.h>
108 #endif
109 #ifdef SFBUF_OPTIONAL_DIRECT_MAP
110 #include <machine/md_var.h>
111 #endif
112
113 #ifdef SFBUF
114 struct sf_buf *sf_buf_alloc(struct vm_page *, int);
115 void sf_buf_free(struct sf_buf *);
116 void sf_buf_ref(struct sf_buf *);
117
118 static inline vm_offset_t
119 sf_buf_kva(struct sf_buf *sf)
120 {
121 #ifdef SFBUF_OPTIONAL_DIRECT_MAP
122 if (SFBUF_OPTIONAL_DIRECT_MAP)
123 return (SFBUF_PHYS_DMAP(VM_PAGE_TO_PHYS((vm_page_t)sf)));
124 #endif
125
126 return (sf->kva);
127 }
128
129 static inline vm_page_t
130 sf_buf_page(struct sf_buf *sf)
131 {
132 #ifdef SFBUF_OPTIONAL_DIRECT_MAP
133 if (SFBUF_OPTIONAL_DIRECT_MAP)
134 return ((vm_page_t)sf);
135 #endif
136
137 return (sf->m);
138 }
139
140 #ifndef SFBUF_MAP
141 #include <vm/pmap.h>
142
143 static inline void
144 sf_buf_map(struct sf_buf *sf, int flags)
145 {
146
147 pmap_qenter(sf->kva, &sf->m, 1);
148 }
149
150 static inline int
151 sf_buf_unmap(struct sf_buf *sf)
152 {
153
154 return (0);
155 }
156 #endif /* SFBUF_MAP */
157
158 #if defined(SMP) && defined(SFBUF_CPUSET)
159 void sf_buf_shootdown(struct sf_buf *, int);
160 #endif
161
162 #ifdef SFBUF_PROCESS_PAGE
163 boolean_t sf_buf_process_page(vm_page_t, void (*)(struct sf_buf *));
164 #endif
165
166 #else /* ! SFBUF */
167
168 static inline struct sf_buf *
169 sf_buf_alloc(struct vm_page *m, int pri)
170 {
171
172 return ((struct sf_buf *)m);
173 }
174
175 static inline void
176 sf_buf_free(struct sf_buf *sf)
177 {
178 }
179
180 static inline void
181 sf_buf_ref(struct sf_buf *sf)
182 {
183 }
184 #endif /* SFBUF */
185
186 /*
187 * Options to sf_buf_alloc() are specified through its flags argument. This
188 * argument's value should be the result of a bitwise or'ing of one or more
189 * of the following values.
190 */
191 #define SFB_CATCH 1 /* Check signals if the allocation
192 sleeps. */
193 #define SFB_CPUPRIVATE 2 /* Create a CPU private mapping. */
194 #define SFB_DEFAULT 0
195 #define SFB_NOWAIT 4 /* Return NULL if all bufs are used. */
196
197 extern counter_u64_t sfstat[sizeof(struct sfstat) / sizeof(uint64_t)];
198 #define SFSTAT_ADD(name, val) \
199 counter_u64_add(sfstat[offsetof(struct sfstat, name) / sizeof(uint64_t)],\
200 (val))
201 #define SFSTAT_INC(name) SFSTAT_ADD(name, 1)
202 #endif /* _KERNEL */
203 #endif /* !_SYS_SF_BUF_H_ */
Cache object: beca8148e56c14a21b5a4bed81d8a561
|