70 lines · c
1// SPDX-License-Identifier: GPL-2.02#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 12static 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 19static int xsd_release(struct inode *inode, struct file *file)20{21 kfree(file->private_data);22 return 0;23}24 25static 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 34static 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 49const 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 56static 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 65const struct file_operations xsd_port_file_ops = {66 .open = xsd_port_open,67 .read = xsd_read,68 .release = xsd_release,69};70