2 * Copyright (c) 2013-2015 Mark R V Murray
3 * Copyright (c) 2013 David E. O'Brien <obrien@NUXI.org>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer
11 * in this position and unchanged.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/kernel.h>
36 #include <sys/malloc.h>
37 #include <sys/module.h>
38 #include <sys/random.h>
39 #include <sys/systm.h>
41 #include <machine/segments.h>
42 #include <machine/pcb.h>
43 #include <machine/md_var.h>
44 #include <machine/specialreg.h>
46 #include <dev/random/randomdev.h>
48 static void random_nehemiah_init(void);
49 static void random_nehemiah_deinit(void);
50 static u_int random_nehemiah_read(void *, u_int);
52 static struct random_source random_nehemiah = {
53 .rs_ident = "VIA Nehemiah Padlock RNG",
54 .rs_source = RANDOM_PURE_NEHEMIAH,
55 .rs_read = random_nehemiah_read
58 static struct fpu_kern_ctx *fpu_ctx_save;
60 /* This H/W source never stores more than 8 bytes in one go */
62 static __inline size_t
63 VIA_RNG_store(void *buf)
72 : "=a" (retval), "+d" (rate), "+D" (buf)
83 random_nehemiah_init(void)
86 fpu_ctx_save = fpu_kern_alloc_ctx(FPU_KERN_NORMAL);
90 random_nehemiah_deinit(void)
93 fpu_kern_free_ctx(fpu_ctx_save);
96 /* It is specifically allowed that buf is a multiple of sizeof(long) */
98 random_nehemiah_read(void *buf, u_int c)
104 if ((fpu_kern_enter(curthread, fpu_ctx_save, FPU_KERN_NORMAL) == 0)) {
106 for (count = c; count > 0; count -= ret) {
107 ret = MIN(VIA_RNG_store(&tmp), count);
108 memcpy(b, &tmp, ret);
111 fpu_kern_leave(curthread, fpu_ctx_save);
120 nehemiah_modevent(module_t mod, int type, void *unused)
126 if (via_feature_rng & VIA_HAS_RNG) {
127 random_source_register(&random_nehemiah);
128 printf("random: fast provider: \"%s\"\n", random_nehemiah.rs_ident);
129 random_nehemiah_init();
134 if (via_feature_rng & VIA_HAS_RNG) {
135 random_nehemiah_deinit();
136 random_source_deregister(&random_nehemiah);
152 DEV_MODULE(nehemiah, nehemiah_modevent, NULL);
153 MODULE_VERSION(nehemiah, 1);
154 MODULE_DEPEND(nehemiah, random_device, 1, 1, 1);