diff options
Diffstat (limited to 'arch/um/drivers/mmapper_kern.c')
-rw-r--r-- | arch/um/drivers/mmapper_kern.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/arch/um/drivers/mmapper_kern.c b/arch/um/drivers/mmapper_kern.c new file mode 100644 index 000000000..62145c276 --- /dev/null +++ b/arch/um/drivers/mmapper_kern.c @@ -0,0 +1,134 @@ +/* + * arch/um/drivers/mmapper_kern.c + * + * BRIEF MODULE DESCRIPTION + * + * Copyright (C) 2000 RidgeRun, Inc. + * Author: RidgeRun, Inc. + * Greg Lonnon glonnon@ridgerun.com or info@ridgerun.com + * + */ + +#include <linux/stddef.h> +#include <linux/types.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/mm.h> + +#include <asm/uaccess.h> +#include <mem_user.h> + +/* These are set in mmapper_init, which is called at boot time */ +static unsigned long mmapper_size; +static unsigned long p_buf; +static char *v_buf; + +static ssize_t mmapper_read(struct file *file, char __user *buf, size_t count, + loff_t *ppos) +{ + return simple_read_from_buffer(buf, count, ppos, v_buf, mmapper_size); +} + +static ssize_t mmapper_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + if (*ppos > mmapper_size) + return -EINVAL; + + return simple_write_to_buffer(v_buf, mmapper_size, ppos, buf, count); +} + +static long mmapper_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + return -ENOIOCTLCMD; +} + +static int mmapper_mmap(struct file *file, struct vm_area_struct *vma) +{ + int ret = -EINVAL; + int size; + + if (vma->vm_pgoff != 0) + goto out; + + size = vma->vm_end - vma->vm_start; + if (size > mmapper_size) + return -EFAULT; + + /* + * XXX A comment above remap_pfn_range says it should only be + * called when the mm semaphore is held + */ + if (remap_pfn_range(vma, vma->vm_start, p_buf >> PAGE_SHIFT, size, + vma->vm_page_prot)) + goto out; + ret = 0; +out: + return ret; +} + +static int mmapper_open(struct inode *inode, struct file *file) +{ + return 0; +} + +static int mmapper_release(struct inode *inode, struct file *file) +{ + return 0; +} + +static const struct file_operations mmapper_fops = { + .owner = THIS_MODULE, + .read = mmapper_read, + .write = mmapper_write, + .unlocked_ioctl = mmapper_ioctl, + .mmap = mmapper_mmap, + .open = mmapper_open, + .release = mmapper_release, + .llseek = default_llseek, +}; + +/* + * No locking needed - only used (and modified) by below initcall and exitcall. + */ +static struct miscdevice mmapper_dev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "mmapper", + .fops = &mmapper_fops +}; + +static int __init mmapper_init(void) +{ + int err; + + printk(KERN_INFO "Mapper v0.1\n"); + + v_buf = (char *) find_iomem("mmapper", &mmapper_size); + if (mmapper_size == 0) { + printk(KERN_ERR "mmapper_init - find_iomem failed\n"); + return -ENODEV; + } + p_buf = __pa(v_buf); + + err = misc_register(&mmapper_dev); + if (err) { + printk(KERN_ERR "mmapper - misc_register failed, err = %d\n", + err); + return err; + } + return 0; +} + +static void mmapper_exit(void) +{ + misc_deregister(&mmapper_dev); +} + +module_init(mmapper_init); +module_exit(mmapper_exit); + +MODULE_AUTHOR("Greg Lonnon <glonnon@ridgerun.com>"); +MODULE_DESCRIPTION("DSPLinux simulator mmapper driver"); +MODULE_LICENSE("GPL"); |