LXR linux/drivers/xen/xenfs/xenstored.c

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