LXR linux/arch/m68k/kernel/bootinfo

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Based on arch/arm/kernel/atags_proc.c
   4 */
   5
   6#include <linux/fs.h>
   7#include <linux/init.h>
   8#include <linux/printk.h>
   9#include <linux/proc_fs.h>
  10#include <linux/slab.h>
  11#include <linux/string.h>
  12
  13#include <asm/bootinfo.h>
  14#include <asm/byteorder.h>
  15
  16
  17static char bootinfo_tmp[1536] __initdata;
  18
  19static void *bootinfo_copy;
  20static size_t bootinfo_size;
  21
  22static ssize_t bootinfo_read(struct file *file, char __user *buf,
  23                          size_t count, loff_t *ppos)
  24{
  25        return simple_read_from_buffer(buf, count, ppos, bootinfo_copy,
  26                                       bootinfo_size);
  27}
  28
  29static const struct proc_ops bootinfo_proc_ops = {
  30        .proc_read      = bootinfo_read,
  31        .proc_lseek     = default_llseek,
  32};
  33
  34void __init save_bootinfo(const struct bi_record *bi)
  35{
  36        const void *start = bi;
  37        size_t size = sizeof(bi->tag);
  38
  39        while (be16_to_cpu(bi->tag) != BI_LAST) {
  40                uint16_t n = be16_to_cpu(bi->size);
  41                size += n;
  42                bi = (struct bi_record *)((unsigned long)bi + n);
  43        }
  44
  45        if (size > sizeof(bootinfo_tmp)) {
  46                pr_err("Cannot save %zu bytes of bootinfo\n", size);
  47                return;
  48        }
  49
  50        pr_info("Saving %zu bytes of bootinfo\n", size);
  51        memcpy(bootinfo_tmp, start, size);
  52        bootinfo_size = size;
  53}
  54
  55static int __init init_bootinfo_procfs(void)
  56{
  57        /*
  58         * This cannot go into save_bootinfo() because kmalloc and proc don't
  59         * work yet when it is called.
  60         */
  61        struct proc_dir_entry *pde;
  62
  63        if (!bootinfo_size)
  64                return -EINVAL;
  65
  66        bootinfo_copy = kmemdup(bootinfo_tmp, bootinfo_size, GFP_KERNEL);
  67        if (!bootinfo_copy)
  68                return -ENOMEM;
  69
  70        pde = proc_create_data("bootinfo", 0400, NULL, &bootinfo_proc_ops, NULL);
  71        if (!pde) {
  72                kfree(bootinfo_copy);
  73                return -ENOMEM;
  74        }
  75
  76        return 0;
  77}
  78
  79arch_initcall(init_bootinfo_procfs);
  80