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1/* Copyright (C) 2005 - 2008 Jeff Dike <jdike@{linux.intel,addtoit}.com> */
2
3/* Much of this ripped from drivers/char/hw_random.c, see there for other
4 * copyright.
5 *
6 * This software may be used and distributed according to the terms
7 * of the GNU General Public License, incorporated herein by reference.
8 */
9#include <linux/sched/signal.h>
10#include <linux/module.h>
11#include <linux/fs.h>
12#include <linux/interrupt.h>
13#include <linux/miscdevice.h>
14#include <linux/hw_random.h>
15#include <linux/delay.h>
16#include <linux/uaccess.h>
17#include <init.h>
18#include <irq_kern.h>
19#include <os.h>
20
21/*
22 * core module information
23 */
24#define RNG_MODULE_NAME "hw_random"
25
26/* Changed at init time, in the non-modular case, and at module load
27 * time, in the module case. Presumably, the module subsystem
28 * protects against a module being loaded twice at the same time.
29 */
30static int random_fd = -1;
31static struct hwrng hwrng;
32static DECLARE_COMPLETION(have_data);
33
34static int rng_dev_read(struct hwrng *rng, void *buf, size_t max, bool block)
35{
36 int ret;
37
38 for (;;) {
39 ret = os_read_file(random_fd, buf, max);
40 if (block && ret == -EAGAIN) {
41 add_sigio_fd(random_fd);
42
43 ret = wait_for_completion_killable(&have_data);
44
45 ignore_sigio_fd(random_fd);
46 deactivate_fd(random_fd, RANDOM_IRQ);
47
48 if (ret < 0)
49 break;
50 } else {
51 break;
52 }
53 }
54
55 return ret != -EAGAIN ? ret : 0;
56}
57
58static irqreturn_t random_interrupt(int irq, void *data)
59{
60 complete(&have_data);
61
62 return IRQ_HANDLED;
63}
64
65/*
66 * rng_init - initialize RNG module
67 */
68static int __init rng_init (void)
69{
70 int err;
71
72 err = os_open_file("/dev/random", of_read(OPENFLAGS()), 0);
73 if (err < 0)
74 goto out;
75
76 random_fd = err;
77 err = um_request_irq(RANDOM_IRQ, random_fd, IRQ_READ, random_interrupt,
78 0, "random", NULL);
79 if (err < 0)
80 goto err_out_cleanup_hw;
81
82 sigio_broken(random_fd);
83 hwrng.name = RNG_MODULE_NAME;
84 hwrng.read = rng_dev_read;
85
86 err = hwrng_register(&hwrng);
87 if (err) {
88 pr_err(RNG_MODULE_NAME " registering failed (%d)\n", err);
89 goto err_out_cleanup_hw;
90 }
91out:
92 return err;
93
94err_out_cleanup_hw:
95 os_close_file(random_fd);
96 random_fd = -1;
97 goto out;
98}
99
100/*
101 * rng_cleanup - shutdown RNG module
102 */
103
104static void cleanup(void)
105{
106 free_irq_by_fd(random_fd);
107 os_close_file(random_fd);
108}
109
110static void __exit rng_cleanup(void)
111{
112 hwrng_unregister(&hwrng);
113 os_close_file(random_fd);
114}
115
116module_init (rng_init);
117module_exit (rng_cleanup);
118__uml_exitcall(cleanup);
119
120MODULE_DESCRIPTION("UML Host Random Number Generator (RNG) driver");
121MODULE_LICENSE("GPL");
1/* Copyright (C) 2005 - 2008 Jeff Dike <jdike@{linux.intel,addtoit}.com> */
2
3/* Much of this ripped from drivers/char/hw_random.c, see there for other
4 * copyright.
5 *
6 * This software may be used and distributed according to the terms
7 * of the GNU General Public License, incorporated herein by reference.
8 */
9#include <linux/sched/signal.h>
10#include <linux/module.h>
11#include <linux/fs.h>
12#include <linux/interrupt.h>
13#include <linux/miscdevice.h>
14#include <linux/hw_random.h>
15#include <linux/delay.h>
16#include <linux/uaccess.h>
17#include <init.h>
18#include <irq_kern.h>
19#include <os.h>
20
21/*
22 * core module information
23 */
24#define RNG_MODULE_NAME "hw_random"
25
26/* Changed at init time, in the non-modular case, and at module load
27 * time, in the module case. Presumably, the module subsystem
28 * protects against a module being loaded twice at the same time.
29 */
30static int random_fd = -1;
31static struct hwrng hwrng;
32static DECLARE_COMPLETION(have_data);
33
34static int rng_dev_read(struct hwrng *rng, void *buf, size_t max, bool block)
35{
36 int ret;
37
38 for (;;) {
39 ret = os_read_file(random_fd, buf, max);
40 if (block && ret == -EAGAIN) {
41 add_sigio_fd(random_fd);
42
43 ret = wait_for_completion_killable(&have_data);
44
45 ignore_sigio_fd(random_fd);
46 deactivate_fd(random_fd, RANDOM_IRQ);
47
48 if (ret < 0)
49 break;
50 } else {
51 break;
52 }
53 }
54
55 return ret != -EAGAIN ? ret : 0;
56}
57
58static irqreturn_t random_interrupt(int irq, void *data)
59{
60 complete(&have_data);
61
62 return IRQ_HANDLED;
63}
64
65/*
66 * rng_init - initialize RNG module
67 */
68static int __init rng_init (void)
69{
70 int err;
71
72 err = os_open_file("/dev/random", of_read(OPENFLAGS()), 0);
73 if (err < 0)
74 goto out;
75
76 random_fd = err;
77 err = um_request_irq(RANDOM_IRQ, random_fd, IRQ_READ, random_interrupt,
78 0, "random", NULL);
79 if (err < 0)
80 goto err_out_cleanup_hw;
81
82 sigio_broken(random_fd);
83 hwrng.name = RNG_MODULE_NAME;
84 hwrng.read = rng_dev_read;
85
86 err = hwrng_register(&hwrng);
87 if (err) {
88 pr_err(RNG_MODULE_NAME " registering failed (%d)\n", err);
89 goto err_out_cleanup_hw;
90 }
91out:
92 return err;
93
94err_out_cleanup_hw:
95 os_close_file(random_fd);
96 random_fd = -1;
97 goto out;
98}
99
100/*
101 * rng_cleanup - shutdown RNG module
102 */
103
104static void cleanup(void)
105{
106 free_irq_by_fd(random_fd);
107 os_close_file(random_fd);
108}
109
110static void __exit rng_cleanup(void)
111{
112 hwrng_unregister(&hwrng);
113 os_close_file(random_fd);
114}
115
116module_init (rng_init);
117module_exit (rng_cleanup);
118__uml_exitcall(cleanup);
119
120MODULE_DESCRIPTION("UML Host Random Number Generator (RNG) driver");
121MODULE_LICENSE("GPL");