1 /*
2 * Copyright (c) 1998 David Greenman. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26 #include <sys/param.h>
27 #include <sys/types.h>
28 #include <sys/systm.h>
29 #include <sys/kernel.h>
30 #include <sys/malloc.h>
31 #include <sys/sfbuf.h>
32 #include <sys/refcount.h>
33 #include <sys/objcache.h>
34
35 #include <cpu/lwbuf.h>
36
37 #include <vm/vm.h>
38 #include <vm/vm_extern.h>
39 #include <vm/vm_kern.h>
40 #include <vm/vm_page.h>
41 #include <vm/pmap.h>
42
43 static void sf_buf_init(void *arg);
44 SYSINIT(sock_sf, SI_BOOT2_MACHDEP, SI_ORDER_ANY, sf_buf_init, NULL);
45
46 static struct objcache *sf_buf_cache;
47
48 MALLOC_DEFINE(M_SFBUF, "sfbuf", "Sendfile buffer structures");
49 static struct objcache_malloc_args sf_buf_malloc_args = {
50 sizeof(struct sf_buf),
51 M_SFBUF
52 };
53
54
55 static boolean_t
sf_buf_cache_ctor(void * obj,void * pdata,int ocflags)56 sf_buf_cache_ctor(void *obj, void *pdata, int ocflags)
57 {
58 struct sf_buf *sf = (struct sf_buf *)obj;
59
60 sf->lwbuf = NULL;
61 refcount_init(&sf->ref, 0);
62
63 return (TRUE);
64 }
65
66 /*
67 * Init objcache of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-))
68 */
69 static void
sf_buf_init(void * arg)70 sf_buf_init(void *arg)
71 {
72 sf_buf_cache = objcache_create("sf_buf", 0, 0,
73 sf_buf_cache_ctor, NULL, NULL,
74 objcache_malloc_alloc, objcache_malloc_free,
75 &sf_buf_malloc_args);
76 }
77
78 /*
79 * Acquire an sf_buf reference for a vm_page.
80 */
81 struct sf_buf *
sf_buf_alloc(struct vm_page * m)82 sf_buf_alloc(struct vm_page *m)
83 {
84 struct sf_buf *sf;
85
86 if ((sf = objcache_get(sf_buf_cache, M_WAITOK)) == NULL)
87 goto done;
88
89 if ((sf->lwbuf = lwbuf_alloc(m, &sf->lwbuf_cache)) == NULL) {
90 objcache_put(sf_buf_cache, sf);
91 sf = NULL;
92 goto done;
93 }
94
95 /*
96 * Force invalidation of the TLB entry on all CPU's
97 */
98 lwbuf_set_global(sf->lwbuf);
99
100 refcount_init(&sf->ref, 1);
101
102 done:
103 return (sf);
104 }
105
106 void
sf_buf_ref(void * arg)107 sf_buf_ref(void *arg)
108 {
109 struct sf_buf *sf = arg;
110
111 refcount_acquire(&sf->ref);
112 }
113
114 /*
115 * Detach mapped page and release resources back to the system.
116 *
117 * Returns non-zero (TRUE) if this was the last release of the sfbuf.
118 *
119 * (matching the same API that refcount_release() uses to reduce confusion)
120 */
121 int
sf_buf_free(void * arg)122 sf_buf_free(void *arg)
123 {
124 struct sf_buf *sf = arg;
125
126 if (refcount_release(&sf->ref)) {
127 lwbuf_free(sf->lwbuf);
128 objcache_put(sf_buf_cache, sf);
129 return (1);
130 }
131 return (0);
132 }
133