summaryrefslogtreecommitdiff
path: root/arch/um/drivers/random.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/um/drivers/random.c')
-rw-r--r--arch/um/drivers/random.c122
1 files changed, 79 insertions, 43 deletions
diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c
index 71f0959c153..4949044773b 100644
--- a/arch/um/drivers/random.c
+++ b/arch/um/drivers/random.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 2005 Jeff Dike <jdike@addtoit.com> */
+/* Copyright (C) 2005 - 2008 Jeff Dike <jdike@{linux.intel,addtoit}.com> */
+
/* Much of this ripped from drivers/char/hw_random.c, see there for other
* copyright.
*
@@ -8,16 +9,18 @@
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/fs.h>
+#include <linux/interrupt.h>
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
+#include "irq_kern.h"
#include "os.h"
/*
* core module and version information
*/
#define RNG_VERSION "1.0.0"
-#define RNG_MODULE_NAME "random"
+#define RNG_MODULE_NAME "hw_random"
#define RNG_MISCDEV_MINOR 183 /* official */
@@ -26,47 +29,67 @@
* protects against a module being loaded twice at the same time.
*/
static int random_fd = -1;
+static DECLARE_WAIT_QUEUE_HEAD(host_read_wait);
static int rng_dev_open (struct inode *inode, struct file *filp)
{
/* enforce read-only access to this chrdev */
if ((filp->f_mode & FMODE_READ) == 0)
return -EINVAL;
- if (filp->f_mode & FMODE_WRITE)
+ if ((filp->f_mode & FMODE_WRITE) != 0)
return -EINVAL;
return 0;
}
+static atomic_t host_sleep_count = ATOMIC_INIT(0);
+
static ssize_t rng_dev_read (struct file *filp, char __user *buf, size_t size,
- loff_t * offp)
+ loff_t *offp)
{
- u32 data;
- int n, ret = 0, have_data;
-
- while(size){
- n = os_read_file(random_fd, &data, sizeof(data));
- if(n > 0){
- have_data = n;
- while (have_data && size) {
- if (put_user((u8)data, buf++)) {
- ret = ret ? : -EFAULT;
- break;
- }
- size--;
- ret++;
- have_data--;
- data>>=8;
- }
- }
- else if(n == -EAGAIN){
- if (filp->f_flags & O_NONBLOCK)
- return ret ? : -EAGAIN;
-
- if(need_resched())
- schedule_timeout_interruptible(1);
- }
- else return n;
+ u32 data;
+ int n, ret = 0, have_data;
+
+ while (size) {
+ n = os_read_file(random_fd, &data, sizeof(data));
+ if (n > 0) {
+ have_data = n;
+ while (have_data && size) {
+ if (put_user((u8) data, buf++)) {
+ ret = ret ? : -EFAULT;
+ break;
+ }
+ size--;
+ ret++;
+ have_data--;
+ data >>= 8;
+ }
+ }
+ else if (n == -EAGAIN) {
+ DECLARE_WAITQUEUE(wait, current);
+
+ if (filp->f_flags & O_NONBLOCK)
+ return ret ? : -EAGAIN;
+
+ atomic_inc(&host_sleep_count);
+ reactivate_fd(random_fd, RANDOM_IRQ);
+ add_sigio_fd(random_fd);
+
+ add_wait_queue(&host_read_wait, &wait);
+ set_task_state(current, TASK_INTERRUPTIBLE);
+
+ schedule();
+ set_task_state(current, TASK_RUNNING);
+ remove_wait_queue(&host_read_wait, &wait);
+
+ if (atomic_dec_and_test(&host_sleep_count)) {
+ ignore_sigio_fd(random_fd);
+ deactivate_fd(random_fd, RANDOM_IRQ);
+ }
+ }
+ else
+ return n;
+
if (signal_pending (current))
return ret ? : -ERESTARTSYS;
}
@@ -86,6 +109,13 @@ static struct miscdevice rng_miscdev = {
&rng_chrdev_ops,
};
+static irqreturn_t random_interrupt(int irq, void *data)
+{
+ wake_up(&host_read_wait);
+
+ return IRQ_HANDLED;
+}
+
/*
* rng_init - initialize RNG module
*/
@@ -93,28 +123,33 @@ static int __init rng_init (void)
{
int err;
- err = os_open_file("/dev/random", of_read(OPENFLAGS()), 0);
- if(err < 0)
- goto out;
+ err = os_open_file("/dev/random", of_read(OPENFLAGS()), 0);
+ if (err < 0)
+ goto out;
- random_fd = err;
+ random_fd = err;
- err = os_set_fd_block(random_fd, 0);
- if(err)
+ err = um_request_irq(RANDOM_IRQ, random_fd, IRQ_READ, random_interrupt,
+ IRQF_DISABLED | IRQF_SAMPLE_RANDOM, "random",
+ NULL);
+ if (err)
goto err_out_cleanup_hw;
+ sigio_broken(random_fd, 1);
+
err = misc_register (&rng_miscdev);
if (err) {
- printk (KERN_ERR RNG_MODULE_NAME ": misc device register failed\n");
+ printk (KERN_ERR RNG_MODULE_NAME ": misc device register "
+ "failed\n");
goto err_out_cleanup_hw;
}
+out:
+ return err;
- out:
- return err;
-
- err_out_cleanup_hw:
- random_fd = -1;
- goto out;
+err_out_cleanup_hw:
+ os_close_file(random_fd);
+ random_fd = -1;
+ goto out;
}
/*
@@ -122,6 +157,7 @@ static int __init rng_init (void)
*/
static void __exit rng_cleanup (void)
{
+ os_close_file(random_fd);
misc_deregister (&rng_miscdev);
}