text: // SPDX-License-Identifier: GPL-2.0
  /*
   * /proc/bus/pnp interface for Plug and Play devices
   *
   * Written by David Hinds, dahinds@users.sourceforge.net
   * Modified by Thomas Hood
   *
   * The .../devices and .../<node> and .../boot/<node> files are
   * utilized by the lspnp and setpnp utilities, supplied with the
   * pcmcia-cs package.
   *     http://pcmcia-cs.sourceforge.net
   *
   * The .../escd file is utilized by the lsescd utility written by
   * Gunther Mayer.
   *
   * The .../legacy_device_resources file is not used yet.
   *
   * The other files are human-readable.
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/types.h>
  #include <linux/proc_fs.h>
  #include <linux/pnp.h>
  #include <linux/seq_file.h>
  #include <linux/init.h>
  
  #include <linux/uaccess.h>
  
  #include "pnpbios.h"
  
  static struct proc_dir_entry *proc_pnp = NULL;
  static struct proc_dir_entry *proc_pnp_boot = NULL;
  
  static int pnpconfig_proc_show(struct seq_file *m, void *v)
  {
  	struct pnp_isa_config_struc pnps;
  
  	if (pnp_bios_isapnp_config(&pnps))
  		return -EIO;
  	seq_printf(m, "structure_revision %d\n"
  		      "number_of_CSNs %d\n"
  		      "ISA_read_data_port 0x%x\n",
  		   pnps.revision, pnps.no_csns, pnps.isa_rd_data_port);
  	return 0;
  }
  
  static int escd_info_proc_show(struct seq_file *m, void *v)
  {
  	struct escd_info_struc escd;
  
  	if (pnp_bios_escd_info(&escd))
  		return -EIO;
  	seq_printf(m, "min_ESCD_write_size %d\n"
  			"ESCD_size %d\n"
  			"NVRAM_base 0x%x\n",
  			escd.min_escd_write_size,
  			escd.escd_size, escd.nv_storage_base);
  	return 0;
  }
  
  #define MAX_SANE_ESCD_SIZE (32*1024)
  static int escd_proc_show(struct seq_file *m, void *v)
  {
  	struct escd_info_struc escd;
  	char *tmpbuf;
  	int escd_size;
  
  	if (pnp_bios_escd_info(&escd))
  		return -EIO;
  
  	/* sanity check */
  	if (escd.escd_size > MAX_SANE_ESCD_SIZE) {
  		printk(KERN_ERR
  		       "PnPBIOS: %s: ESCD size reported by BIOS escd_info call is too great\n", __func__);
  		return -EFBIG;
  	}
  
  	tmpbuf = kzalloc(escd.escd_size, GFP_KERNEL);
  	if (!tmpbuf)
  		return -ENOMEM;
  
  	if (pnp_bios_read_escd(tmpbuf, escd.nv_storage_base)) {
  		kfree(tmpbuf);
  		return -EIO;
  	}
  
  	escd_size =
  	    (unsigned char)(tmpbuf[0]) + (unsigned char)(tmpbuf[1]) * 256;
  
  	/* sanity check */
  	if (escd_size > MAX_SANE_ESCD_SIZE) {
  		printk(KERN_ERR "PnPBIOS: %s: ESCD size reported by"
  				" BIOS read_escd call is too great\n", __func__);
  		kfree(tmpbuf);
  		return -EFBIG;
  	}
  
  	seq_write(m, tmpbuf, escd_size);
  	kfree(tmpbuf);
  	return 0;
  }
  
  static int pnp_legacyres_proc_show(struct seq_file *m, void *v)
  {
  	void *buf;
  
  	buf = kmalloc(65536, GFP_KERNEL);
  	if (!buf)
  		return -ENOMEM;
  	if (pnp_bios_get_stat_res(buf)) {
  		kfree(buf);
  		return -EIO;
  	}
  
  	seq_write(m, buf, 65536);
  	kfree(buf);
  	return 0;
  }
  
  static int pnp_devices_proc_show(struct seq_file *m, void *v)
  {
  	struct pnp_bios_node *node;
  	u8 nodenum;
  
  	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
  	if (!node)
  		return -ENOMEM;
  
  	for (nodenum = 0; nodenum < 0xff;) {
  		u8 thisnodenum = nodenum;
  
  		if (pnp_bios_get_dev_node(&nodenum, PNPMODE_DYNAMIC, node))
  			break;
  		seq_printf(m, "%02x\t%08x\t%3phC\t%04x\n",
  			     node->handle, node->eisa_id,
  			     node->type_code, node->flags);
  		if (nodenum <= thisnodenum) {
  			printk(KERN_ERR
  			       "%s Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
  			       "PnPBIOS: proc_read_devices:",
  			       (unsigned int)nodenum,
  			       (unsigned int)thisnodenum);
  			break;
  		}
  	}
  	kfree(node);
  	return 0;
  }
  
  static int pnpbios_proc_show(struct seq_file *m, void *v)
  {
  	void *data = m->private;
  	struct pnp_bios_node *node;
  	int boot = (long)data >> 8;
  	u8 nodenum = (long)data;
  	int len;
  
  	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
  	if (!node)
  		return -ENOMEM;
  	if (pnp_bios_get_dev_node(&nodenum, boot, node)) {
  		kfree(node);
  		return -EIO;
  	}
  	len = node->size - sizeof(struct pnp_bios_node);
  	seq_write(m, node->data, len);
  	kfree(node);
  	return 0;
  }
  
  static int pnpbios_proc_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, pnpbios_proc_show, PDE_DATA(inode));
  }
  
  static ssize_t pnpbios_proc_write(struct file *file, const char __user *buf,
  				  size_t count, loff_t *pos)
  {
  	void *data = PDE_DATA(file_inode(file));
  	struct pnp_bios_node *node;
  	int boot = (long)data >> 8;
  	u8 nodenum = (long)data;
  	int ret = count;
  
  	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
  	if (!node)
  		return -ENOMEM;
  	if (pnp_bios_get_dev_node(&nodenum, boot, node)) {
  		ret = -EIO;
  		goto out;
  	}
  	if (count != node->size - sizeof(struct pnp_bios_node)) {
  		ret = -EINVAL;
  		goto out;
  	}
  	if (copy_from_user(node->data, buf, count)) {
  		ret = -EFAULT;
  		goto out;
  	}
  	if (pnp_bios_set_dev_node(node->handle, boot, node) != 0) {
  		ret = -EINVAL;
  		goto out;
  	}
  	ret = count;
  out:
  	kfree(node);
  	return ret;
  }
  
  static const struct proc_ops pnpbios_proc_ops = {
  	.proc_open	= pnpbios_proc_open,
  	.proc_read	= seq_read,
  	.proc_lseek	= seq_lseek,
  	.proc_release	= single_release,
  	.proc_write	= pnpbios_proc_write,
  };
  
  int pnpbios_interface_attach_device(struct pnp_bios_node *node)
  {
  	char name[3];
  
  	sprintf(name, "%02x", node->handle);
  
  	if (!proc_pnp)
  		return -EIO;
  	if (!pnpbios_dont_use_current_config) {
  		proc_create_data(name, 0644, proc_pnp, &pnpbios_proc_ops,
  				 (void *)(long)(node->handle));
  	}
  
  	if (!proc_pnp_boot)
  		return -EIO;
  	if (proc_create_data(name, 0644, proc_pnp_boot, &pnpbios_proc_ops,
  			     (void *)(long)(node->handle + 0x100)))
  		return 0;
  	return -EIO;
  }
  
  /*
   * When this is called, pnpbios functions are assumed to
   * work and the pnpbios_dont_use_current_config flag
   * should already have been set to the appropriate value
   */
  int __init pnpbios_proc_init(void)
  {
  	proc_pnp = proc_mkdir("bus/pnp", NULL);
  	if (!proc_pnp)
  		return -EIO;
  	proc_pnp_boot = proc_mkdir("boot", proc_pnp);
  	if (!proc_pnp_boot)
  		return -EIO;
  	proc_create_single("devices", 0, proc_pnp, pnp_devices_proc_show);
  	proc_create_single("configuration_info", 0, proc_pnp,
  			pnpconfig_proc_show);
  	proc_create_single("escd_info", 0, proc_pnp, escd_info_proc_show);
  	proc_create_single("escd", S_IRUSR, proc_pnp, escd_proc_show);
  	proc_create_single("legacy_device_resources", 0, proc_pnp,
  			pnp_legacyres_proc_show);
  	return 0;
  }
  
  void __exit pnpbios_proc_exit(void)
  {
  	int i;
  	char name[3];
  
  	if (!proc_pnp)
  		return;
  
  	for (i = 0; i < 0xff; i++) {
  		sprintf(name, "%02x", i);
  		if (!pnpbios_dont_use_current_config)
  			remove_proc_entry(name, proc_pnp);
  		remove_proc_entry(name, proc_pnp_boot);
  	}
  	remove_proc_entry("legacy_device_resources", proc_pnp);
  	remove_proc_entry("escd", proc_pnp);
  	remove_proc_entry("escd_info", proc_pnp);
  	remove_proc_entry("configuration_info", proc_pnp);
  	remove_proc_entry("devices", proc_pnp);
  	remove_proc_entry("boot", proc_pnp);
  	remove_proc_entry("bus/pnp", NULL);
  }
  