// SPDX-License-Identifier: GPL-2.0-only
/*
 * Architecture specific debugfs files
 *
 * Copyright (C) 2007, Intel Corp.
 *      Huang Ying <ying.huang@intel.com>
 */
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/stat.h>
#include <linux/io.h>
#include <linux/mm.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;
        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 + pos;

        /* Is it direct data or invalid indirect one? */
        if (!(node->type & SETUP_INDIRECT) || node->type == SETUP_INDIRECT)
                pa += sizeof(struct setup_data);

        p = memremap(pa, count, MEMREMAP_WB);
        if (!p)
                return -ENOMEM;

        remain = copy_to_user(user_buf, p, count);

        memunmap(p);

        if (remain)
                return -EFAULT;

        *ppos = pos + count;

        return count;
}

static const struct file_operations fops_setup_data = {
        .read           = setup_data_read,
        .open           = simple_open,
        .llseek         = default_llseek,
};

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

        sprintf(buf, "%d", no);
        d = debugfs_create_dir(buf, parent);

        debugfs_create_x32("type", S_IRUGO, d, &node->type);
        debugfs_create_file("data", S_IRUGO, d, node, &fops_setup_data);
}

static int __init create_setup_data_nodes(struct dentry *parent)
{
        struct setup_indirect *indirect;
        struct setup_data_node *node;
        struct setup_data *data;
        u64 pa_data, pa_next;
        struct dentry *d;
        int error;
        u32 len;
        int no = 0;

        d = debugfs_create_dir("setup_data", parent);

        pa_data = boot_params.hdr.setup_data;

        while (pa_data) {
                node = kmalloc_obj(*node);
                if (!node) {
                        error = -ENOMEM;
                        goto err_dir;
                }

                data = memremap(pa_data, sizeof(*data), MEMREMAP_WB);
                if (!data) {
                        kfree(node);
                        error = -ENOMEM;
                        goto err_dir;
                }
                pa_next = data->next;

                if (data->type == SETUP_INDIRECT) {
                        len = sizeof(*data) + data->len;
                        memunmap(data);
                        data = memremap(pa_data, len, MEMREMAP_WB);
                        if (!data) {
                                kfree(node);
                                error = -ENOMEM;
                                goto err_dir;
                        }

                        indirect = (struct setup_indirect *)data->data;

                        if (indirect->type != SETUP_INDIRECT) {
                                node->paddr = indirect->addr;
                                node->type  = indirect->type;
                                node->len   = indirect->len;
                        } else {
                                node->paddr = pa_data;
                                node->type  = data->type;
                                node->len   = data->len;
                        }
                } else {
                        node->paddr = pa_data;
                        node->type  = data->type;
                        node->len   = data->len;
                }

                create_setup_data_node(d, no, node);
                pa_data = pa_next;

                memunmap(data);
                no++;
        }

        return 0;

err_dir:
        debugfs_remove_recursive(d);
        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;
        int error;

        dbp = debugfs_create_dir("boot_params", arch_debugfs_dir);

        debugfs_create_x16("version", S_IRUGO, dbp, &boot_params.hdr.version);
        debugfs_create_blob("data", S_IRUGO, dbp, &boot_params_blob);

        error = create_setup_data_nodes(dbp);
        if (error)
                debugfs_remove_recursive(dbp);

        return error;
}
#endif /* CONFIG_DEBUG_BOOT_PARAMS */

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

        arch_debugfs_dir = debugfs_create_dir("x86", NULL);

#ifdef CONFIG_DEBUG_BOOT_PARAMS
        error = boot_params_kdebugfs_init();
#endif

        return error;
}
arch_initcall(arch_kdebugfs_init);