1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/slab.h>
3 #include <linux/types.h>
4 #include <linux/mm.h>
5 #include <linux/fs.h>
6 
7 #include <xen/page.h>
8 #include <xen/xenbus.h>
9 
10 #include "xenfs.h"
11 
xsd_read(struct file * file,char __user * buf,size_t size,loff_t * off)12 static ssize_t xsd_read(struct file *file, char __user *buf,
13 			    size_t size, loff_t *off)
14 {
15 	const char *str = (const char *)file->private_data;
16 	return simple_read_from_buffer(buf, size, off, str, strlen(str));
17 }
18 
xsd_release(struct inode * inode,struct file * file)19 static int xsd_release(struct inode *inode, struct file *file)
20 {
21 	kfree(file->private_data);
22 	return 0;
23 }
24 
xsd_kva_open(struct inode * inode,struct file * file)25 static int xsd_kva_open(struct inode *inode, struct file *file)
26 {
27 	file->private_data = (void *)kasprintf(GFP_KERNEL, "0x%p",
28 					       xen_store_interface);
29 	if (!file->private_data)
30 		return -ENOMEM;
31 	return 0;
32 }
33 
xsd_kva_mmap(struct file * file,struct vm_area_struct * vma)34 static int xsd_kva_mmap(struct file *file, struct vm_area_struct *vma)
35 {
36 	size_t size = vma->vm_end - vma->vm_start;
37 
38 	if ((size > PAGE_SIZE) || (vma->vm_pgoff != 0))
39 		return -EINVAL;
40 
41 	if (remap_pfn_range(vma, vma->vm_start,
42 			    virt_to_pfn(xen_store_interface),
43 			    size, vma->vm_page_prot))
44 		return -EAGAIN;
45 
46 	return 0;
47 }
48 
49 const struct file_operations xsd_kva_file_ops = {
50 	.open = xsd_kva_open,
51 	.mmap = xsd_kva_mmap,
52 	.read = xsd_read,
53 	.release = xsd_release,
54 };
55 
xsd_port_open(struct inode * inode,struct file * file)56 static int xsd_port_open(struct inode *inode, struct file *file)
57 {
58 	file->private_data = (void *)kasprintf(GFP_KERNEL, "%d",
59 					       xen_store_evtchn);
60 	if (!file->private_data)
61 		return -ENOMEM;
62 	return 0;
63 }
64 
65 const struct file_operations xsd_port_file_ops = {
66 	.open = xsd_port_open,
67 	.read = xsd_read,
68 	.release = xsd_release,
69 };
70