linux/arch/x86/kernel/kdebugfs.c
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   1/*
   2 * Architecture specific debugfs files
   3 *
   4 * Copyright (C) 2007, Intel Corp.
   5 *      Huang Ying <ying.huang@intel.com>
   6 *
   7 * This file is released under the GPLv2.
   8 */
   9#include <linux/debugfs.h>
  10#include <linux/uaccess.h>
  11#include <linux/stat.h>
  12#include <linux/init.h>
  13#include <linux/io.h>
  14#include <linux/mm.h>
  15#include <linux/module.h>
  16
  17#include <asm/setup.h>
  18
  19struct dentry *arch_debugfs_dir;
  20EXPORT_SYMBOL(arch_debugfs_dir);
  21
  22#ifdef CONFIG_DEBUG_BOOT_PARAMS
  23struct setup_data_node {
  24        u64 paddr;
  25        u32 type;
  26        u32 len;
  27};
  28
  29static ssize_t
  30setup_data_read(struct file *file, char __user *user_buf, size_t count,
  31                loff_t *ppos)
  32{
  33        struct setup_data_node *node = file->private_data;
  34        unsigned long remain;
  35        loff_t pos = *ppos;
  36        struct page *pg;
  37        void *p;
  38        u64 pa;
  39
  40        if (pos < 0)
  41                return -EINVAL;
  42        if (pos >= node->len)
  43                return 0;
  44
  45        if (count > node->len - pos)
  46                count = node->len - pos;
  47        pa = node->paddr + sizeof(struct setup_data) + pos;
  48        pg = pfn_to_page((pa + count - 1) >> PAGE_SHIFT);
  49        if (PageHighMem(pg)) {
  50                p = ioremap_cache(pa, count);
  51                if (!p)
  52                        return -ENXIO;
  53        } else {
  54                p = __va(pa);
  55        }
  56
  57        remain = copy_to_user(user_buf, p, count);
  58
  59        if (PageHighMem(pg))
  60                iounmap(p);
  61
  62        if (remain)
  63                return -EFAULT;
  64
  65        *ppos = pos + count;
  66
  67        return count;
  68}
  69
  70static int setup_data_open(struct inode *inode, struct file *file)
  71{
  72        file->private_data = inode->i_private;
  73        return 0;
  74}
  75
  76static const struct file_operations fops_setup_data = {
  77        .read =         setup_data_read,
  78        .open =         setup_data_open,
  79};
  80
  81static int __init
  82create_setup_data_node(struct dentry *parent, int no,
  83                       struct setup_data_node *node)
  84{
  85        struct dentry *d, *type, *data;
  86        char buf[16];
  87        int error;
  88
  89        sprintf(buf, "%d", no);
  90        d = debugfs_create_dir(buf, parent);
  91        if (!d) {
  92                error = -ENOMEM;
  93                goto err_return;
  94        }
  95        type = debugfs_create_x32("type", S_IRUGO, d, &node->type);
  96        if (!type) {
  97                error = -ENOMEM;
  98                goto err_dir;
  99        }
 100        data = debugfs_create_file("data", S_IRUGO, d, node, &fops_setup_data);
 101        if (!data) {
 102                error = -ENOMEM;
 103                goto err_type;
 104        }
 105        return 0;
 106
 107err_type:
 108        debugfs_remove(type);
 109err_dir:
 110        debugfs_remove(d);
 111err_return:
 112        return error;
 113}
 114
 115static int __init create_setup_data_nodes(struct dentry *parent)
 116{
 117        struct setup_data_node *node;
 118        struct setup_data *data;
 119        int error, no = 0;
 120        struct dentry *d;
 121        struct page *pg;
 122        u64 pa_data;
 123
 124        d = debugfs_create_dir("setup_data", parent);
 125        if (!d) {
 126                error = -ENOMEM;
 127                goto err_return;
 128        }
 129
 130        pa_data = boot_params.hdr.setup_data;
 131
 132        while (pa_data) {
 133                node = kmalloc(sizeof(*node), GFP_KERNEL);
 134                if (!node) {
 135                        error = -ENOMEM;
 136                        goto err_dir;
 137                }
 138                pg = pfn_to_page((pa_data+sizeof(*data)-1) >> PAGE_SHIFT);
 139                if (PageHighMem(pg)) {
 140                        data = ioremap_cache(pa_data, sizeof(*data));
 141                        if (!data) {
 142                                kfree(node);
 143                                error = -ENXIO;
 144                                goto err_dir;
 145                        }
 146                } else {
 147                        data = __va(pa_data);
 148                }
 149
 150                node->paddr = pa_data;
 151                node->type = data->type;
 152                node->len = data->len;
 153                error = create_setup_data_node(d, no, node);
 154                pa_data = data->next;
 155
 156                if (PageHighMem(pg))
 157                        iounmap(data);
 158                if (error)
 159                        goto err_dir;
 160                no++;
 161        }
 162        return 0;
 163
 164err_dir:
 165        debugfs_remove(d);
 166err_return:
 167        return error;
 168}
 169
 170static struct debugfs_blob_wrapper boot_params_blob = {
 171        .data           = &boot_params,
 172        .size           = sizeof(boot_params),
 173};
 174
 175static int __init boot_params_kdebugfs_init(void)
 176{
 177        struct dentry *dbp, *version, *data;
 178        int error;
 179
 180        dbp = debugfs_create_dir("boot_params", NULL);
 181        if (!dbp) {
 182                error = -ENOMEM;
 183                goto err_return;
 184        }
 185        version = debugfs_create_x16("version", S_IRUGO, dbp,
 186                                     &boot_params.hdr.version);
 187        if (!version) {
 188                error = -ENOMEM;
 189                goto err_dir;
 190        }
 191        data = debugfs_create_blob("data", S_IRUGO, dbp,
 192                                   &boot_params_blob);
 193        if (!data) {
 194                error = -ENOMEM;
 195                goto err_version;
 196        }
 197        error = create_setup_data_nodes(dbp);
 198        if (error)
 199                goto err_data;
 200        return 0;
 201
 202err_data:
 203        debugfs_remove(data);
 204err_version:
 205        debugfs_remove(version);
 206err_dir:
 207        debugfs_remove(dbp);
 208err_return:
 209        return error;
 210}
 211#endif
 212
 213static int __init arch_kdebugfs_init(void)
 214{
 215        int error = 0;
 216
 217        arch_debugfs_dir = debugfs_create_dir("x86", NULL);
 218        if (!arch_debugfs_dir)
 219                return -ENOMEM;
 220
 221#ifdef CONFIG_DEBUG_BOOT_PARAMS
 222        error = boot_params_kdebugfs_init();
 223#endif
 224
 225        return error;
 226}
 227arch_initcall(arch_kdebugfs_init);
 228
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