diff options
Diffstat (limited to 'arch/um/drivers/random.c')
| -rw-r--r-- | arch/um/drivers/random.c | 41 |
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); } |