root/arch/x86/kernel/kdebugfs.c

DEFINITIONS

1. setup_data_read
2. setup_data_open
3. create_setup_data_node
4. create_setup_data_nodes
5. boot_params_kdebugfs_init
6. arch_kdebugfs_init

/*
 * Architecture specific debugfs files
 *
 * Copyright (C) 2007, Intel Corp.
 *      Huang Ying <ying.huang@intel.com>
 *
 * This file is released under the GPLv2.
 */
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/module.h>

#include <asm/setup.h>

struct dentry *arch_debugfs_dir;
EXPORT_SYMBOL(arch_debugfs_dir);

#ifdef CONFIG_DEBUG_BOOT_PARAMS
struct setup_data_node {
        u64 paddr;
        u32 type;
        u32 len;
};

static ssize_t
setup_data_read(struct file *file, char __user *user_buf, size_t count,
                loff_t *ppos)
{
        struct setup_data_node *node = file->private_data;
        unsigned long remain;
        loff_t pos = *ppos;
        struct page *pg;
        void *p;
        u64 pa;

        if (pos < 0)
                return -EINVAL;
        if (pos >= node->len)
                return 0;

        if (count > node->len - pos)
                count = node->len - pos;
        pa = node->paddr + sizeof(struct setup_data) + pos;
        pg = pfn_to_page((pa + count - 1) >> PAGE_SHIFT);
        if (PageHighMem(pg)) {
                p = ioremap_cache(pa, count);
                if (!p)
                        return -ENXIO;
        } else {
                p = __va(pa);
        }

        remain = copy_to_user(user_buf, p, count);

        if (PageHighMem(pg))
                iounmap(p);

        if (remain)
                return -EFAULT;

        *ppos = pos + count;

        return count;
}

static int setup_data_open(struct inode *inode, struct file *file)
{
        file->private_data = inode->i_private;
        return 0;
}

static const struct file_operations fops_setup_data = {
        .read =         setup_data_read,
        .open =         setup_data_open,
};

static int __init
create_setup_data_node(struct dentry *parent, int no,
                       struct setup_data_node *node)
{
        struct dentry *d, *type, *data;
        char buf[16];
        int error;

        sprintf(buf, "%d", no);
        d = debugfs_create_dir(buf, parent);
        if (!d) {
                error = -ENOMEM;
                goto err_return;
        }
        type = debugfs_create_x32("type", S_IRUGO, d, &node->type);
        if (!type) {
                error = -ENOMEM;
                goto err_dir;
        }
        data = debugfs_create_file("data", S_IRUGO, d, node, &fops_setup_data);
        if (!data) {
                error = -ENOMEM;
                goto err_type;
        }
        return 0;

err_type:
        debugfs_remove(type);
err_dir:
        debugfs_remove(d);
err_return:
        return error;
}

static int __init create_setup_data_nodes(struct dentry *parent)
{
        struct setup_data_node *node;
        struct setup_data *data;
        int error, no = 0;
        struct dentry *d;
        struct page *pg;
        u64 pa_data;

        d = debugfs_create_dir("setup_data", parent);
        if (!d) {
                error = -ENOMEM;
                goto err_return;
        }

        pa_data = boot_params.hdr.setup_data;

        while (pa_data) {
                node = kmalloc(sizeof(*node), GFP_KERNEL);
                if (!node) {
                        error = -ENOMEM;
                        goto err_dir;
                }
                pg = pfn_to_page((pa_data+sizeof(*data)-1) >> PAGE_SHIFT);
                if (PageHighMem(pg)) {
                        data = ioremap_cache(pa_data, sizeof(*data));
                        if (!data) {
                                kfree(node);
                                error = -ENXIO;
                                goto err_dir;
                        }
                } else {
                        data = __va(pa_data);
                }

                node->paddr = pa_data;
                node->type = data->type;
                node->len = data->len;
                error = create_setup_data_node(d, no, node);
                pa_data = data->next;

                if (PageHighMem(pg))
                        iounmap(data);
                if (error)
                        goto err_dir;
                no++;
        }
        return 0;

err_dir:
        debugfs_remove(d);
err_return:
        return error;
}

static struct debugfs_blob_wrapper boot_params_blob = {
        .data           = &boot_params,
        .size           = sizeof(boot_params),
};

static int __init boot_params_kdebugfs_init(void)
{
        struct dentry *dbp, *version, *data;
        int error;

        dbp = debugfs_create_dir("boot_params", NULL);
        if (!dbp) {
                error = -ENOMEM;
                goto err_return;
        }
        version = debugfs_create_x16("version", S_IRUGO, dbp,
                                     &boot_params.hdr.version);
        if (!version) {
                error = -ENOMEM;
                goto err_dir;
        }
        data = debugfs_create_blob("data", S_IRUGO, dbp,
                                   &boot_params_blob);
        if (!data) {
                error = -ENOMEM;
                goto err_version;
        }
        error = create_setup_data_nodes(dbp);
        if (error)
                goto err_data;
        return 0;

err_data:
        debugfs_remove(data);
err_version:
        debugfs_remove(version);
err_dir:
        debugfs_remove(dbp);
err_return:
        return error;
}
#endif

static int __init arch_kdebugfs_init(void)
{
        int error = 0;

        arch_debugfs_dir = debugfs_create_dir("x86", NULL);
        if (!arch_debugfs_dir)
                return -ENOMEM;

#ifdef CONFIG_DEBUG_BOOT_PARAMS
        error = boot_params_kdebugfs_init();
#endif

        return error;
}
arch_initcall(arch_kdebugfs_init);