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 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 19 static int xsd_release(struct inode *inode, struct file *file) 20 { 21 kfree(file->private_data); 22 return 0; 23 } 24 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 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 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