/* * 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");