1// SPDX-License-Identifier: GPL-2.0
2/*
3 * /proc/bus/pnp interface for Plug and Play devices
4 *
5 * Written by David Hinds, dahinds@users.sourceforge.net
6 * Modified by Thomas Hood
7 *
8 * The .../devices and .../<node> and .../boot/<node> files are
9 * utilized by the lspnp and setpnp utilities, supplied with the
10 * pcmcia-cs package.
11 *     http://pcmcia-cs.sourceforge.net
12 *
13 * The .../escd file is utilized by the lsescd utility written by
14 * Gunther Mayer.
15 *
16 * The .../legacy_device_resources file is not used yet.
17 *
18 * The other files are human-readable.
19 */
20
21#include <linux/module.h>
22#include <linux/kernel.h>
23#include <linux/slab.h>
24#include <linux/types.h>
25#include <linux/proc_fs.h>
26#include <linux/pnp.h>
27#include <linux/seq_file.h>
28#include <linux/init.h>
29
30#include <linux/uaccess.h>
31
32#include "pnpbios.h"
33
34static struct proc_dir_entry *proc_pnp = NULL;
35static struct proc_dir_entry *proc_pnp_boot = NULL;
36
37static int pnpconfig_proc_show(struct seq_file *m, void *v)
38{
39	struct pnp_isa_config_struc pnps;
40
41	if (pnp_bios_isapnp_config(&pnps))
42		return -EIO;
43	seq_printf(m, "structure_revision %d\n"
44		      "number_of_CSNs %d\n"
45		      "ISA_read_data_port 0x%x\n",
46		   pnps.revision, pnps.no_csns, pnps.isa_rd_data_port);
47	return 0;
48}
49
50static int escd_info_proc_show(struct seq_file *m, void *v)
51{
52	struct escd_info_struc escd;
53
54	if (pnp_bios_escd_info(&escd))
55		return -EIO;
56	seq_printf(m, "min_ESCD_write_size %d\n"
57			"ESCD_size %d\n"
58			"NVRAM_base 0x%x\n",
59			escd.min_escd_write_size,
60			escd.escd_size, escd.nv_storage_base);
61	return 0;
62}
63
64#define MAX_SANE_ESCD_SIZE (32*1024)
65static int escd_proc_show(struct seq_file *m, void *v)
66{
67	struct escd_info_struc escd;
68	char *tmpbuf;
69	int escd_size;
70
71	if (pnp_bios_escd_info(&escd))
72		return -EIO;
73
74	/* sanity check */
75	if (escd.escd_size > MAX_SANE_ESCD_SIZE) {
76		printk(KERN_ERR
77		       "PnPBIOS: %s: ESCD size reported by BIOS escd_info call is too great\n", __func__);
78		return -EFBIG;
79	}
80
81	tmpbuf = kzalloc(escd.escd_size, GFP_KERNEL);
82	if (!tmpbuf)
83		return -ENOMEM;
84
85	if (pnp_bios_read_escd(tmpbuf, escd.nv_storage_base)) {
86		kfree(tmpbuf);
87		return -EIO;
88	}
89
90	escd_size =
91	    (unsigned char)(tmpbuf[0]) + (unsigned char)(tmpbuf[1]) * 256;
92
93	/* sanity check */
94	if (escd_size > MAX_SANE_ESCD_SIZE) {
95		printk(KERN_ERR "PnPBIOS: %s: ESCD size reported by"
96				" BIOS read_escd call is too great\n", __func__);
97		kfree(tmpbuf);
98		return -EFBIG;
99	}
100
101	seq_write(m, tmpbuf, escd_size);
102	kfree(tmpbuf);
103	return 0;
104}
105
106static int pnp_legacyres_proc_show(struct seq_file *m, void *v)
107{
108	void *buf;
109
110	buf = kmalloc(65536, GFP_KERNEL);
111	if (!buf)
112		return -ENOMEM;
113	if (pnp_bios_get_stat_res(buf)) {
114		kfree(buf);
115		return -EIO;
116	}
117
118	seq_write(m, buf, 65536);
119	kfree(buf);
120	return 0;
121}
122
123static int pnp_devices_proc_show(struct seq_file *m, void *v)
124{
125	struct pnp_bios_node *node;
126	u8 nodenum;
127
128	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
129	if (!node)
130		return -ENOMEM;
131
132	for (nodenum = 0; nodenum < 0xff;) {
133		u8 thisnodenum = nodenum;
134
135		if (pnp_bios_get_dev_node(&nodenum, PNPMODE_DYNAMIC, node))
136			break;
137		seq_printf(m, "%02x\t%08x\t%3phC\t%04x\n",
138			     node->handle, node->eisa_id,
139			     node->type_code, node->flags);
140		if (nodenum <= thisnodenum) {
141			printk(KERN_ERR
142			       "%s Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
143			       "PnPBIOS: proc_read_devices:",
144			       (unsigned int)nodenum,
145			       (unsigned int)thisnodenum);
146			break;
147		}
148	}
149	kfree(node);
150	return 0;
151}
152
153static int pnpbios_proc_show(struct seq_file *m, void *v)
154{
155	void *data = m->private;
156	struct pnp_bios_node *node;
157	int boot = (long)data >> 8;
158	u8 nodenum = (long)data;
159	int len;
160
161	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
162	if (!node)
163		return -ENOMEM;
164	if (pnp_bios_get_dev_node(&nodenum, boot, node)) {
165		kfree(node);
166		return -EIO;
167	}
168	len = node->size - sizeof(struct pnp_bios_node);
169	seq_write(m, node->data, len);
170	kfree(node);
171	return 0;
172}
173
174static int pnpbios_proc_open(struct inode *inode, struct file *file)
175{
176	return single_open(file, pnpbios_proc_show, pde_data(inode));
177}
178
179static ssize_t pnpbios_proc_write(struct file *file, const char __user *buf,
180				  size_t count, loff_t *pos)
181{
182	void *data = pde_data(file_inode(file));
183	struct pnp_bios_node *node;
184	int boot = (long)data >> 8;
185	u8 nodenum = (long)data;
186	int ret = count;
187
188	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
189	if (!node)
190		return -ENOMEM;
191	if (pnp_bios_get_dev_node(&nodenum, boot, node)) {
192		ret = -EIO;
193		goto out;
194	}
195	if (count != node->size - sizeof(struct pnp_bios_node)) {
196		ret = -EINVAL;
197		goto out;
198	}
199	if (copy_from_user(node->data, buf, count)) {
200		ret = -EFAULT;
201		goto out;
202	}
203	if (pnp_bios_set_dev_node(node->handle, boot, node) != 0) {
204		ret = -EINVAL;
205		goto out;
206	}
207	ret = count;
208out:
209	kfree(node);
210	return ret;
211}
212
213static const struct proc_ops pnpbios_proc_ops = {
214	.proc_open	= pnpbios_proc_open,
215	.proc_read	= seq_read,
216	.proc_lseek	= seq_lseek,
217	.proc_release	= single_release,
218	.proc_write	= pnpbios_proc_write,
219};
220
221int pnpbios_interface_attach_device(struct pnp_bios_node *node)
222{
223	char name[3];
224
225	sprintf(name, "%02x", node->handle);
226
227	if (!proc_pnp)
228		return -EIO;
229	if (!pnpbios_dont_use_current_config) {
230		proc_create_data(name, 0644, proc_pnp, &pnpbios_proc_ops,
231				 (void *)(long)(node->handle));
232	}
233
234	if (!proc_pnp_boot)
235		return -EIO;
236	if (proc_create_data(name, 0644, proc_pnp_boot, &pnpbios_proc_ops,
237			     (void *)(long)(node->handle + 0x100)))
238		return 0;
239	return -EIO;
240}
241
242/*
243 * When this is called, pnpbios functions are assumed to
244 * work and the pnpbios_dont_use_current_config flag
245 * should already have been set to the appropriate value
246 */
247int __init pnpbios_proc_init(void)
248{
249	proc_pnp = proc_mkdir("bus/pnp", NULL);
250	if (!proc_pnp)
251		return -EIO;
252	proc_pnp_boot = proc_mkdir("boot", proc_pnp);
253	if (!proc_pnp_boot)
254		return -EIO;
255	proc_create_single("devices", 0, proc_pnp, pnp_devices_proc_show);
256	proc_create_single("configuration_info", 0, proc_pnp,
257			pnpconfig_proc_show);
258	proc_create_single("escd_info", 0, proc_pnp, escd_info_proc_show);
259	proc_create_single("escd", S_IRUSR, proc_pnp, escd_proc_show);
260	proc_create_single("legacy_device_resources", 0, proc_pnp,
261			pnp_legacyres_proc_show);
262	return 0;
263}
264
265void __exit pnpbios_proc_exit(void)
266{
267	int i;
268	char name[3];
269
270	if (!proc_pnp)
271		return;
272
273	for (i = 0; i < 0xff; i++) {
274		sprintf(name, "%02x", i);
275		if (!pnpbios_dont_use_current_config)
276			remove_proc_entry(name, proc_pnp);
277		remove_proc_entry(name, proc_pnp_boot);
278	}
279	remove_proc_entry("legacy_device_resources", proc_pnp);
280	remove_proc_entry("escd", proc_pnp);
281	remove_proc_entry("escd_info", proc_pnp);
282	remove_proc_entry("configuration_info", proc_pnp);
283	remove_proc_entry("devices", proc_pnp);
284	remove_proc_entry("boot", proc_pnp);
285	remove_proc_entry("bus/pnp", NULL);
286}
287