blob: 04ddf779a57e0f41d4559a0b1491a3dda873d849 [file] [log] [blame]
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
#include <linux/fs.h> // file_operations
#include <linux/device.h> // class_create
#include <linux/cdev.h> // cdev
#include <linux/mm.h> // VM_IO
#include <linux/module.h>
#include <asm/uaccess.h>
static unsigned char __HOSTLINK__ [4 * PAGE_SIZE]
__attribute__((aligned (PAGE_SIZE)));
static int arc_hl_mmap(struct file *fp, struct vm_area_struct *vma);
static int arc_hl_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg);
static struct file_operations arc_hl_fops = {
.owner = THIS_MODULE,
.ioctl = arc_hl_ioctl,
.mmap = arc_hl_mmap,
static int arc_hl_major;
static int arc_hl_minor;
static int arc_hl_nr_devs = 1;
static char arc_hl_devnm[]="hostlink";
static struct cdev arc_hl_cdev;
static struct class *arc_hl_class;
static int __init arc_hl_linux_glue(void)
dev_t arc_hl_dev;
int i;
if (arc_hl_major) { // Preallocated MAJOR
arc_hl_dev = MKDEV( arc_hl_major, arc_hl_minor );
register_chrdev_region( arc_hl_dev, arc_hl_nr_devs, arc_hl_devnm);
else { // allocates Major to devices
alloc_chrdev_region(&arc_hl_dev, 0, arc_hl_nr_devs, arc_hl_devnm);
arc_hl_major = MAJOR(arc_hl_dev);
// Populate sysfs entries: creates /sys/class/ sub-node for your device
arc_hl_class = class_create(THIS_MODULE, arc_hl_devnm);
// connect file ops with cdev
cdev_init(&arc_hl_cdev, &arc_hl_fops);
arc_hl_cdev.owner = THIS_MODULE;
// Connect major/minor number to cdev
// makes device available.
// device nodes created with 'mknod` are probably already active.
cdev_add(&arc_hl_cdev, arc_hl_dev, arc_hl_nr_devs);
// creates /sys/devices/virtual/<dev_name>/<names[i]> node with
// link from/sys/class/<dev_name>, needed by mdev.
for (i = 0; i < arc_hl_nr_devs; i++)
device_create(arc_hl_class,NULL,MKDEV(MAJOR(arc_hl_dev), i), NULL, arc_hl_devnm);
printk("Hostlink dev to mknod is %d:%d\n",arc_hl_major, arc_hl_minor);
return 0;
static int __init arc_hl_init(void)
printk("Hostlink shared mem PHY addr to mmap is 0x%p\n",__HOSTLINK__);
return 0;
static int arc_hl_mmap(struct file *fp, struct vm_area_struct *vma)
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
// printk("@ ARC Linux HostLink Drv %lx %lx %lx %lx\n",
// vma->vm_start, vma->vm_end, vma->vm_pgoff, vma->vm_page_prot);
if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
vma->vm_end - vma->vm_start, vma->vm_page_prot)) {
printk("@#$## ARC Hostlink ERROR in mmap\n");
return -EAGAIN;
return 0;
static int arc_hl_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
// we only support, returning the physical addr to mmap in user space
put_user(__HOSTLINK__, (int __user *)arg);
return 0;