diff options
| -rw-r--r-- | arch/um/drivers/random.c | 101 | ||||
| -rw-r--r-- | drivers/char/hw_random/Kconfig | 16 |
2 files changed, 33 insertions, 84 deletions
diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c index ce115fce52f0..e4b9b2ce9abf 100644 --- a/arch/um/drivers/random.c +++ b/arch/um/drivers/random.c @@ -11,6 +11,7 @@ #include <linux/fs.h> #include <linux/interrupt.h> #include <linux/miscdevice.h> +#include <linux/hw_random.h> #include <linux/delay.h> #include <linux/uaccess.h> #include <init.h> @@ -18,9 +19,8 @@ #include <os.h> /* - * core module and version information + * core module information */ -#define RNG_VERSION "1.0.0" #define RNG_MODULE_NAME "hw_random" /* Changed at init time, in the non-modular case, and at module load @@ -28,88 +28,36 @@ * 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 struct hwrng hwrng = { 0, }; +static DECLARE_COMPLETION(have_data); -static int rng_dev_open (struct inode *inode, struct file *filp) +static int rng_dev_read(struct hwrng *rng, void *buf, size_t max, bool block) { - /* enforce read-only access to this chrdev */ - if ((filp->f_mode & FMODE_READ) == 0) - return -EINVAL; - if ((filp->f_mode & FMODE_WRITE) != 0) - return -EINVAL; + int ret; - 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) -{ - 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); + for (;;) { + ret = os_read_file(random_fd, buf, max); + if (block && ret == -EAGAIN) { add_sigio_fd(random_fd); - add_wait_queue(&host_read_wait, &wait); - set_current_state(TASK_INTERRUPTIBLE); + ret = wait_for_completion_killable(&have_data); - schedule(); - remove_wait_queue(&host_read_wait, &wait); + ignore_sigio_fd(random_fd); + deactivate_fd(random_fd, RANDOM_IRQ); - if (atomic_dec_and_test(&host_sleep_count)) { - ignore_sigio_fd(random_fd); - deactivate_fd(random_fd, RANDOM_IRQ); - } + if (ret < 0) + break; + } else { + break; } - else - return n; - - if (signal_pending (current)) - return ret ? : -ERESTARTSYS; } - return ret; -} -static const struct file_operations rng_chrdev_ops = { - .owner = THIS_MODULE, - .open = rng_dev_open, - .read = rng_dev_read, - .llseek = noop_llseek, -}; - -/* rng_init shouldn't be called more than once at boot time */ -static struct miscdevice rng_miscdev = { - HWRNG_MINOR, - RNG_MODULE_NAME, - &rng_chrdev_ops, -}; + return ret != -EAGAIN ? ret : 0; +} static irqreturn_t random_interrupt(int irq, void *data) { - wake_up(&host_read_wait); + complete(&have_data); return IRQ_HANDLED; } @@ -126,18 +74,19 @@ static int __init rng_init (void) goto out; random_fd = err; - err = um_request_irq(RANDOM_IRQ, random_fd, IRQ_READ, random_interrupt, 0, "random", NULL); if (err) goto err_out_cleanup_hw; sigio_broken(random_fd, 1); + hwrng.name = RNG_MODULE_NAME; + hwrng.read = rng_dev_read; + hwrng.quality = 1024; - err = misc_register (&rng_miscdev); + err = hwrng_register(&hwrng); if (err) { - printk (KERN_ERR RNG_MODULE_NAME ": misc device register " - "failed\n"); + pr_err(RNG_MODULE_NAME " registering failed (%d)\n", err); goto err_out_cleanup_hw; } out: @@ -161,8 +110,8 @@ static void cleanup(void) static void __exit rng_cleanup(void) { + hwrng_unregister(&hwrng); os_close_file(random_fd); - misc_deregister (&rng_miscdev); } module_init (rng_init); diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index e92c4d9469d8..5952210526aa 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -540,15 +540,15 @@ endif # HW_RANDOM config UML_RANDOM depends on UML - tristate "Hardware random number generator" + select HW_RANDOM + tristate "UML Random Number Generator support" help This option enables UML's "hardware" random number generator. It attaches itself to the host's /dev/random, supplying as much entropy as the host has, rather than the small amount the UML gets from its - own drivers. It registers itself as a standard hardware random number - generator, major 10, minor 183, and the canonical device name is - /dev/hwrng. - The way to make use of this is to install the rng-tools package - (check your distro, or download from - http://sourceforge.net/projects/gkernel/). rngd periodically reads - /dev/hwrng and injects the entropy into /dev/random. + own drivers. It registers itself as a rng-core driver thus providing + a device which is usually called /dev/hwrng. This hardware random + number generator does feed into the kernel's random number generator + entropy pool. + + If unsure, say Y. |