1 files changed, 79 insertions, 43 deletions

diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c
index 71f0959c1535..4949044773ba 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);
 }