arch/m68k/kernel/bootinfo_proc.c

   1 /*
   2  * Based on arch/arm/kernel/atags_proc.c
   3  */
   4
   5 #include <linux/fs.h>
   6 #include <linux/init.h>
   7 #include <linux/printk.h>
   8 #include <linux/proc_fs.h>
   9 #include <linux/slab.h>
  10 #include <linux/string.h>
  11
  12 #include <asm/bootinfo.h>
  13 #include <asm/byteorder.h>
  14
  15
  16 static char bootinfo_tmp[1536] __initdata;
  17
  18 static void *bootinfo_copy;
  19 static size_t bootinfo_size;
  20
  21 static ssize_t bootinfo_read(struct file *file, char __user *buf,
  22                           size_t count, loff_t *ppos)
  23 {
  24         return simple_read_from_buffer(buf, count, ppos, bootinfo_copy,
  25                                        bootinfo_size);
  26 }
  27
  28 static const struct file_operations bootinfo_fops = {
  29         .read = bootinfo_read,
  30         .llseek = default_llseek,
  31 };
  32
  33 void __init save_bootinfo(const struct bi_record *bi)
  34 {
  35         const void *start = bi;
  36         size_t size = sizeof(bi->tag);
  37
  38         while (be16_to_cpu(bi->tag) != BI_LAST) {
  39                 uint16_t n = be16_to_cpu(bi->size);
  40                 size += n;
  41                 bi = (struct bi_record *)((unsigned long)bi + n);
  42         }
  43
  44         if (size > sizeof(bootinfo_tmp)) {
  45                 pr_err("Cannot save %zu bytes of bootinfo\n", size);
  46                 return;
  47         }
  48
  49         pr_info("Saving %zu bytes of bootinfo\n", size);
  50         memcpy(bootinfo_tmp, start, size);
  51         bootinfo_size = size;
  52 }
  53
  54 static int __init init_bootinfo_procfs(void)
  55 {
  56         /*
  57          * This cannot go into save_bootinfo() because kmalloc and proc don't
  58          * work yet when it is called.
  59          */
  60         struct proc_dir_entry *pde;
  61
  62         if (!bootinfo_size)
  63                 return -EINVAL;
  64
  65         bootinfo_copy = kmalloc(bootinfo_size, GFP_KERNEL);
  66         if (!bootinfo_copy)
  67                 return -ENOMEM;
  68
  69         memcpy(bootinfo_copy, bootinfo_tmp, bootinfo_size);
  70
  71         pde = proc_create_data("bootinfo", 0400, NULL, &bootinfo_fops, NULL);
  72         if (!pde) {
  73                 kfree(bootinfo_copy);
  74                 return -ENOMEM;
  75         }
  76
  77         return 0;
  78 }
  79
  80 arch_initcall(init_bootinfo_procfs);