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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/um/drivers/random.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/um/drivers/random.c')
-rw-r--r-- | arch/um/drivers/random.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c new file mode 100644 index 000000000000..d43e9fab05a7 --- /dev/null +++ b/arch/um/drivers/random.c @@ -0,0 +1,122 @@ +/* Much of this ripped from hw_random.c */ + +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/delay.h> +#include <asm/uaccess.h> +#include "os.h" + +/* + * core module and version information + */ +#define RNG_VERSION "1.0.0" +#define RNG_MODULE_NAME "random" +#define RNG_DRIVER_NAME RNG_MODULE_NAME " virtual driver " RNG_VERSION +#define PFX RNG_MODULE_NAME ": " + +#define RNG_MISCDEV_MINOR 183 /* official */ + +static int random_fd = -1; + +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) + return -EINVAL; + + return 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){ + if (filp->f_flags & O_NONBLOCK) + return ret ? : -EAGAIN; + + if(need_resched()){ + current->state = TASK_INTERRUPTIBLE; + schedule_timeout(1); + } + } + else return n; + if (signal_pending (current)) + return ret ? : -ERESTARTSYS; + } + return ret; +} + +static struct file_operations rng_chrdev_ops = { + .owner = THIS_MODULE, + .open = rng_dev_open, + .read = rng_dev_read, +}; + +static struct miscdevice rng_miscdev = { + RNG_MISCDEV_MINOR, + RNG_MODULE_NAME, + &rng_chrdev_ops, +}; + +/* + * rng_init - initialize RNG module + */ +static int __init rng_init (void) +{ + int err; + + err = os_open_file("/dev/random", of_read(OPENFLAGS()), 0); + if(err < 0) + goto out; + + random_fd = err; + + err = os_set_fd_block(random_fd, 0); + if(err) + goto err_out_cleanup_hw; + + err = misc_register (&rng_miscdev); + if (err) { + printk (KERN_ERR PFX "misc device register failed\n"); + goto err_out_cleanup_hw; + } + + out: + return err; + + err_out_cleanup_hw: + random_fd = -1; + goto out; +} + +/* + * rng_cleanup - shutdown RNG module + */ +static void __exit rng_cleanup (void) +{ + misc_deregister (&rng_miscdev); +} + +module_init (rng_init); +module_exit (rng_cleanup); |