]>
Commit | Line | Data |
---|---|---|
cbe056f7 VG |
1 | /* |
2 | * arc_hostlink.c: Pseudo-driver for Metaware provided "hostlink" facility | |
3 | * | |
4 | * Allows Linux userland access to host in absence of any peripherals. | |
5 | * | |
6 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include <linux/fs.h> /* file_operations */ | |
14 | #include <linux/miscdevice.h> | |
15 | #include <linux/mm.h> /* VM_IO */ | |
16 | #include <linux/module.h> | |
17 | #include <linux/uaccess.h> | |
18 | ||
19 | static unsigned char __HOSTLINK__[4 * PAGE_SIZE] __aligned(PAGE_SIZE); | |
20 | ||
21 | static int arc_hl_mmap(struct file *fp, struct vm_area_struct *vma) | |
22 | { | |
23 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); | |
24 | ||
25 | if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, | |
26 | vma->vm_end - vma->vm_start, | |
27 | vma->vm_page_prot)) { | |
28 | pr_warn("Hostlink buffer mmap ERROR\n"); | |
29 | return -EAGAIN; | |
30 | } | |
31 | return 0; | |
32 | } | |
33 | ||
34 | static long arc_hl_ioctl(struct file *file, unsigned int cmd, | |
35 | unsigned long arg) | |
36 | { | |
37 | /* we only support, returning the physical addr to mmap in user space */ | |
38 | put_user((unsigned int)__HOSTLINK__, (int __user *)arg); | |
39 | return 0; | |
40 | } | |
41 | ||
42 | static const struct file_operations arc_hl_fops = { | |
43 | .unlocked_ioctl = arc_hl_ioctl, | |
44 | .mmap = arc_hl_mmap, | |
45 | }; | |
46 | ||
47 | static struct miscdevice arc_hl_dev = { | |
48 | .minor = MISC_DYNAMIC_MINOR, | |
49 | .name = "hostlink", | |
50 | .fops = &arc_hl_fops | |
51 | }; | |
52 | ||
53 | static int __init arc_hl_init(void) | |
54 | { | |
55 | pr_info("ARC Hostlink driver mmap at 0x%p\n", __HOSTLINK__); | |
56 | return misc_register(&arc_hl_dev); | |
57 | } | |
58 | module_init(arc_hl_init); |