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Diffstat (limited to 'arch/um/drivers/random.c')
-rw-r--r--arch/um/drivers/random.c41
1 files changed, 37 insertions, 4 deletions
diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c
index 71f0959c1535..f92b7c81eb00 100644
--- a/arch/um/drivers/random.c
+++ b/arch/um/drivers/random.c
@@ -8,16 +8,18 @@
#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 */
@@ -26,6 +28,7 @@
* 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)
{
@@ -38,6 +41,8 @@ static int rng_dev_open (struct inode *inode, struct file *filp)
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)
{
@@ -60,11 +65,26 @@ static ssize_t rng_dev_read (struct file *filp, char __user *buf, size_t size,
}
}
else if(n == -EAGAIN){
+ DECLARE_WAITQUEUE(wait, current);
+
if (filp->f_flags & O_NONBLOCK)
return ret ? : -EAGAIN;
- if(need_resched())
- schedule_timeout_interruptible(1);
+ 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))
@@ -86,6 +106,13 @@ 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
*/
@@ -99,10 +126,14 @@ static int __init rng_init (void)
random_fd = err;
- err = os_set_fd_block(random_fd, 0);
+ 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");
@@ -113,6 +144,7 @@ static int __init rng_init (void)
return err;
err_out_cleanup_hw:
+ os_close_file(random_fd);
random_fd = -1;
goto out;
}
@@ -122,6 +154,7 @@ static int __init rng_init (void)
*/
static void __exit rng_cleanup (void)
{
+ os_close_file(random_fd);
misc_deregister (&rng_miscdev);
}