Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394...

[linux-2.6-omap-h63xx.git] / arch / um / drivers / random.c

diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c
index 71f0959c15357b4587cd10c816d3eca1db1fbe92..6eabb7022a2d6c1c45a7f62327a50c4b1c88d734 100644 (file)
--- 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.
  *
@@ -6,18 +7,21 @@
  * of the GNU General Public License, incorporated herein by reference.
  */
 #include <linux/sched.h>
+#include <linux/smp_lock.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 +30,69 @@
  * 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)
 {
+       cycle_kernel_lock();
+
        /* 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 +112,13 @@ 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 +126,33 @@ 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 +160,7 @@ static int __init rng_init (void)
  */
 static void __exit rng_cleanup (void)
 {
+       os_close_file(random_fd);
        misc_deregister (&rng_miscdev);
 }