LXR linux/arch/powerpc/kernel/proc

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen IBM Corporation
   4 */
   5
   6#include <linux/init.h>
   7#include <linux/mm.h>
   8#include <linux/proc_fs.h>
   9#include <linux/kernel.h>
  10
  11#include <asm/machdep.h>
  12#include <asm/vdso_datapage.h>
  13#include <asm/rtas.h>
  14#include <linux/uaccess.h>
  15#include <asm/prom.h>
  16
  17#ifdef CONFIG_PPC64
  18
  19static loff_t page_map_seek(struct file *file, loff_t off, int whence)
  20{
  21        return fixed_size_llseek(file, off, whence, PAGE_SIZE);
  22}
  23
  24static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
  25                              loff_t *ppos)
  26{
  27        return simple_read_from_buffer(buf, nbytes, ppos,
  28                        PDE_DATA(file_inode(file)), PAGE_SIZE);
  29}
  30
  31static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
  32{
  33        if ((vma->vm_end - vma->vm_start) > PAGE_SIZE)
  34                return -EINVAL;
  35
  36        remap_pfn_range(vma, vma->vm_start,
  37                        __pa(PDE_DATA(file_inode(file))) >> PAGE_SHIFT,
  38                        PAGE_SIZE, vma->vm_page_prot);
  39        return 0;
  40}
  41
  42static const struct proc_ops page_map_proc_ops = {
  43        .proc_lseek     = page_map_seek,
  44        .proc_read      = page_map_read,
  45        .proc_mmap      = page_map_mmap,
  46};
  47
  48
  49static int __init proc_ppc64_init(void)
  50{
  51        struct proc_dir_entry *pde;
  52
  53        pde = proc_create_data("powerpc/systemcfg", S_IFREG | 0444, NULL,
  54                               &page_map_proc_ops, vdso_data);
  55        if (!pde)
  56                return 1;
  57        proc_set_size(pde, PAGE_SIZE);
  58
  59        return 0;
  60}
  61__initcall(proc_ppc64_init);
  62
  63#endif /* CONFIG_PPC64 */
  64
  65/*
  66 * Create the ppc64 and ppc64/rtas directories early. This allows us to
  67 * assume that they have been previously created in drivers.
  68 */
  69static int __init proc_ppc64_create(void)
  70{
  71        struct proc_dir_entry *root;
  72
  73        root = proc_mkdir("powerpc", NULL);
  74        if (!root)
  75                return 1;
  76
  77#ifdef CONFIG_PPC64
  78        if (!proc_symlink("ppc64", NULL, "powerpc"))
  79                pr_err("Failed to create link /proc/ppc64 -> /proc/powerpc\n");
  80#endif
  81
  82        if (!of_find_node_by_path("/rtas"))
  83                return 0;
  84
  85        if (!proc_mkdir("rtas", root))
  86                return 1;
  87
  88        if (!proc_symlink("rtas", NULL, "powerpc/rtas"))
  89                return 1;
  90
  91        return 0;
  92}
  93core_initcall(proc_ppc64_create);
  94