1/* 2 * arch/um/drivers/mmapper_kern.c 3 * 4 * BRIEF MODULE DESCRIPTION 5 * 6 * Copyright (C) 2000 RidgeRun, Inc. 7 * Author: RidgeRun, Inc. 8 * Greg Lonnon glonnon@ridgerun.com or info@ridgerun.com 9 * 10 */ 11 12#include <linux/stddef.h> 13#include <linux/types.h> 14#include <linux/fs.h> 15#include <linux/init.h> 16#include <linux/miscdevice.h> 17#include <linux/module.h> 18#include <linux/mm.h> 19 20#include <asm/uaccess.h> 21#include "mem_user.h" 22 23/* These are set in mmapper_init, which is called at boot time */ 24static unsigned long mmapper_size; 25static unsigned long p_buf; 26static char *v_buf; 27 28static ssize_t mmapper_read(struct file *file, char __user *buf, size_t count, 29 loff_t *ppos) 30{ 31 return simple_read_from_buffer(buf, count, ppos, v_buf, mmapper_size); 32} 33 34static ssize_t mmapper_write(struct file *file, const char __user *buf, 35 size_t count, loff_t *ppos) 36{ 37 if (*ppos > mmapper_size) 38 return -EINVAL; 39 40 if (count > mmapper_size - *ppos) 41 count = mmapper_size - *ppos; 42 43 if (copy_from_user(&v_buf[*ppos], buf, count)) 44 return -EFAULT; 45 46 return count; 47} 48 49static long mmapper_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 50{ 51 return -ENOIOCTLCMD; 52} 53 54static int mmapper_mmap(struct file *file, struct vm_area_struct *vma) 55{ 56 int ret = -EINVAL; 57 int size; 58 59 if (vma->vm_pgoff != 0) 60 goto out; 61 62 size = vma->vm_end - vma->vm_start; 63 if (size > mmapper_size) 64 return -EFAULT; 65 66 if (remap_pfn_range(vma, vma->vm_start, p_buf >> PAGE_SHIFT, size, 67 vma->vm_page_prot)) 68 goto out; 69 ret = 0; 70out: 71 return ret; 72} 73 74static int mmapper_open(struct inode *inode, struct file *file) 75{ 76 return 0; 77} 78 79static int mmapper_release(struct inode *inode, struct file *file) 80{ 81 return 0; 82} 83 84static const struct file_operations mmapper_fops = { 85 .owner = THIS_MODULE, 86 .read = mmapper_read, 87 .write = mmapper_write, 88 .unlocked_ioctl = mmapper_ioctl, 89 .mmap = mmapper_mmap, 90 .open = mmapper_open, 91 .release = mmapper_release, 92}; 93 94/* 95 * No locking needed - only used (and modified) by below initcall and exitcall. 96 */ 97static struct miscdevice mmapper_dev = { 98 .minor = MISC_DYNAMIC_MINOR, 99 .name = "mmapper", 100 .fops = &mmapper_fops 101}; 102 103static int __init mmapper_init(void) 104{ 105 int err; 106 107 printk(KERN_INFO "Mapper v0.1\n"); 108 109 v_buf = (char *) find_iomem("mmapper", &mmapper_size); 110 if (mmapper_size == 0) { 111 printk(KERN_ERR "mmapper_init - find_iomem failed\n"); 112 return -ENODEV; 113 } 114 p_buf = __pa(v_buf); 115 116 err = misc_register(&mmapper_dev); 117 if (err) { 118 printk(KERN_ERR "mmapper - misc_register failed, err = %d\n", 119 err); 120 return err;; 121 } 122 return 0; 123} 124 125static void mmapper_exit(void) 126{ 127 misc_deregister(&mmapper_dev); 128} 129 130module_init(mmapper_init); 131module_exit(mmapper_exit); 132 133MODULE_AUTHOR("Greg Lonnon <glonnon@ridgerun.com>"); 134MODULE_DESCRIPTION("DSPLinux simulator mmapper driver"); 135