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/init.h> 13#include <linux/module.h> 14#include <linux/mm.h> 15#include <linux/miscdevice.h> 16#include <asm/uaccess.h> 17#include "mem_user.h" 18 19/* These are set in mmapper_init, which is called at boot time */ 20static unsigned long mmapper_size; 21static unsigned long p_buf = 0; 22static char *v_buf = NULL; 23 24static ssize_t 25mmapper_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) 26{ 27 return simple_read_from_buffer(buf, count, ppos, v_buf, mmapper_size); 28} 29 30static ssize_t 31mmapper_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) 32{ 33 if (*ppos > mmapper_size) 34 return -EINVAL; 35 36 if (count > mmapper_size - *ppos) 37 count = mmapper_size - *ppos; 38 39 if (copy_from_user(&v_buf[*ppos], buf, count)) 40 return -EFAULT; 41 42 return count; 43} 44 45static int 46mmapper_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 47 unsigned long arg) 48{ 49 return(-ENOIOCTLCMD); 50} 51 52static int 53mmapper_mmap(struct file *file, struct vm_area_struct * vma) 54{ 55 int ret = -EINVAL; 56 int size; 57 58 if (vma->vm_pgoff != 0) 59 goto out; 60 61 size = vma->vm_end - vma->vm_start; 62 if(size > mmapper_size) return(-EFAULT); 63 64 if (remap_pfn_range(vma, vma->vm_start, p_buf >> PAGE_SHIFT, size, 65 vma->vm_page_prot)) 66 goto out; 67 ret = 0; 68out: 69 return ret; 70} 71 72static int 73mmapper_open(struct inode *inode, struct file *file) 74{ 75 return 0; 76} 77 78static int 79mmapper_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 .ioctl = mmapper_ioctl, 89 .mmap = mmapper_mmap, 90 .open = mmapper_open, 91 .release = mmapper_release, 92}; 93 94/* No locking needed - only used (and modified) by below initcall and exitcall. */ 95static struct miscdevice mmapper_dev = { 96 .minor = MISC_DYNAMIC_MINOR, 97 .name = "mmapper", 98 .fops = &mmapper_fops 99}; 100 101static int __init mmapper_init(void) 102{ 103 int err; 104 105 printk(KERN_INFO "Mapper v0.1\n"); 106 107 v_buf = (char *) find_iomem("mmapper", &mmapper_size); 108 if(mmapper_size == 0){ 109 printk(KERN_ERR "mmapper_init - find_iomem failed\n"); 110 goto out; 111 } 112 113 err = misc_register(&mmapper_dev); 114 if(err){ 115 printk(KERN_ERR "mmapper - misc_register failed, err = %d\n", 116 err); 117 goto out; 118 } 119 120 p_buf = __pa(v_buf); 121out: 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/* 136 * --------------------------------------------------------------------------- 137 * Local variables: 138 * c-file-style: "linux" 139 * End: 140 */ 141