xref: /openbmc/linux/drivers/pnp/pnpbios/proc.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
1 /*
2  * /proc/bus/pnp interface for Plug and Play devices
3  *
4  * Written by David Hinds, dahinds@users.sourceforge.net
5  * Modified by Thomas Hood
6  *
7  * The .../devices and .../<node> and .../boot/<node> files are
8  * utilized by the lspnp and setpnp utilities, supplied with the
9  * pcmcia-cs package.
10  *     http://pcmcia-cs.sourceforge.net
11  *
12  * The .../escd file is utilized by the lsescd utility written by
13  * Gunther Mayer.
14  *     http://home.t-online.de/home/gunther.mayer/lsescd
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/init.h>
28 
29 #include <asm/uaccess.h>
30 
31 #include "pnpbios.h"
32 
33 static struct proc_dir_entry *proc_pnp = NULL;
34 static struct proc_dir_entry *proc_pnp_boot = NULL;
35 
36 static int proc_read_pnpconfig(char *buf, char **start, off_t pos,
37 			       int count, int *eof, void *data)
38 {
39 	struct pnp_isa_config_struc pnps;
40 
41 	if (pnp_bios_isapnp_config(&pnps))
42 		return -EIO;
43 	return snprintf(buf, count,
44 			"structure_revision %d\n"
45 			"number_of_CSNs %d\n"
46 			"ISA_read_data_port 0x%x\n",
47 			pnps.revision, pnps.no_csns, pnps.isa_rd_data_port);
48 }
49 
50 static int proc_read_escdinfo(char *buf, char **start, off_t pos,
51 			      int count, int *eof, void *data)
52 {
53 	struct escd_info_struc escd;
54 
55 	if (pnp_bios_escd_info(&escd))
56 		return -EIO;
57 	return snprintf(buf, count,
58 			"min_ESCD_write_size %d\n"
59 			"ESCD_size %d\n"
60 			"NVRAM_base 0x%x\n",
61 			escd.min_escd_write_size,
62 			escd.escd_size, escd.nv_storage_base);
63 }
64 
65 #define MAX_SANE_ESCD_SIZE (32*1024)
66 static int proc_read_escd(char *buf, char **start, off_t pos,
67 			  int count, int *eof, void *data)
68 {
69 	struct escd_info_struc escd;
70 	char *tmpbuf;
71 	int escd_size, escd_left_to_read, n;
72 
73 	if (pnp_bios_escd_info(&escd))
74 		return -EIO;
75 
76 	/* sanity check */
77 	if (escd.escd_size > MAX_SANE_ESCD_SIZE) {
78 		printk(KERN_ERR
79 		       "PnPBIOS: proc_read_escd: ESCD size reported by BIOS escd_info call is too great\n");
80 		return -EFBIG;
81 	}
82 
83 	tmpbuf = kzalloc(escd.escd_size, GFP_KERNEL);
84 	if (!tmpbuf)
85 		return -ENOMEM;
86 
87 	if (pnp_bios_read_escd(tmpbuf, escd.nv_storage_base)) {
88 		kfree(tmpbuf);
89 		return -EIO;
90 	}
91 
92 	escd_size =
93 	    (unsigned char)(tmpbuf[0]) + (unsigned char)(tmpbuf[1]) * 256;
94 
95 	/* sanity check */
96 	if (escd_size > MAX_SANE_ESCD_SIZE) {
97 		printk(KERN_ERR "PnPBIOS: proc_read_escd: ESCD size reported by"
98 				" BIOS read_escd call is too great\n");
99 		kfree(tmpbuf);
100 		return -EFBIG;
101 	}
102 
103 	escd_left_to_read = escd_size - pos;
104 	if (escd_left_to_read < 0)
105 		escd_left_to_read = 0;
106 	if (escd_left_to_read == 0)
107 		*eof = 1;
108 	n = min(count, escd_left_to_read);
109 	memcpy(buf, tmpbuf + pos, n);
110 	kfree(tmpbuf);
111 	*start = buf;
112 	return n;
113 }
114 
115 static int proc_read_legacyres(char *buf, char **start, off_t pos,
116 			       int count, int *eof, void *data)
117 {
118 	/* Assume that the following won't overflow the buffer */
119 	if (pnp_bios_get_stat_res(buf))
120 		return -EIO;
121 
122 	return count;		// FIXME: Return actual length
123 }
124 
125 static int proc_read_devices(char *buf, char **start, off_t pos,
126 			     int count, int *eof, void *data)
127 {
128 	struct pnp_bios_node *node;
129 	u8 nodenum;
130 	char *p = buf;
131 
132 	if (pos >= 0xff)
133 		return 0;
134 
135 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
136 	if (!node)
137 		return -ENOMEM;
138 
139 	for (nodenum = pos; nodenum < 0xff;) {
140 		u8 thisnodenum = nodenum;
141 		/* 26 = the number of characters per line sprintf'ed */
142 		if ((p - buf + 26) > count)
143 			break;
144 		if (pnp_bios_get_dev_node(&nodenum, PNPMODE_DYNAMIC, node))
145 			break;
146 		p += sprintf(p, "%02x\t%08x\t%02x:%02x:%02x\t%04x\n",
147 			     node->handle, node->eisa_id,
148 			     node->type_code[0], node->type_code[1],
149 			     node->type_code[2], node->flags);
150 		if (nodenum <= thisnodenum) {
151 			printk(KERN_ERR
152 			       "%s Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
153 			       "PnPBIOS: proc_read_devices:",
154 			       (unsigned int)nodenum,
155 			       (unsigned int)thisnodenum);
156 			*eof = 1;
157 			break;
158 		}
159 	}
160 	kfree(node);
161 	if (nodenum == 0xff)
162 		*eof = 1;
163 	*start = (char *)((off_t) nodenum - pos);
164 	return p - buf;
165 }
166 
167 static int proc_read_node(char *buf, char **start, off_t pos,
168 			  int count, int *eof, void *data)
169 {
170 	struct pnp_bios_node *node;
171 	int boot = (long)data >> 8;
172 	u8 nodenum = (long)data;
173 	int len;
174 
175 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
176 	if (!node)
177 		return -ENOMEM;
178 	if (pnp_bios_get_dev_node(&nodenum, boot, node)) {
179 		kfree(node);
180 		return -EIO;
181 	}
182 	len = node->size - sizeof(struct pnp_bios_node);
183 	memcpy(buf, node->data, len);
184 	kfree(node);
185 	return len;
186 }
187 
188 static int proc_write_node(struct file *file, const char __user * buf,
189 			   unsigned long count, void *data)
190 {
191 	struct pnp_bios_node *node;
192 	int boot = (long)data >> 8;
193 	u8 nodenum = (long)data;
194 	int ret = count;
195 
196 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
197 	if (!node)
198 		return -ENOMEM;
199 	if (pnp_bios_get_dev_node(&nodenum, boot, node)) {
200 		ret = -EIO;
201 		goto out;
202 	}
203 	if (count != node->size - sizeof(struct pnp_bios_node)) {
204 		ret = -EINVAL;
205 		goto out;
206 	}
207 	if (copy_from_user(node->data, buf, count)) {
208 		ret = -EFAULT;
209 		goto out;
210 	}
211 	if (pnp_bios_set_dev_node(node->handle, boot, node) != 0) {
212 		ret = -EINVAL;
213 		goto out;
214 	}
215 	ret = count;
216 out:
217 	kfree(node);
218 	return ret;
219 }
220 
221 int pnpbios_interface_attach_device(struct pnp_bios_node *node)
222 {
223 	char name[3];
224 	struct proc_dir_entry *ent;
225 
226 	sprintf(name, "%02x", node->handle);
227 
228 	if (!proc_pnp)
229 		return -EIO;
230 	if (!pnpbios_dont_use_current_config) {
231 		ent = create_proc_entry(name, 0, proc_pnp);
232 		if (ent) {
233 			ent->read_proc = proc_read_node;
234 			ent->write_proc = proc_write_node;
235 			ent->data = (void *)(long)(node->handle);
236 		}
237 	}
238 
239 	if (!proc_pnp_boot)
240 		return -EIO;
241 	ent = create_proc_entry(name, 0, proc_pnp_boot);
242 	if (ent) {
243 		ent->read_proc = proc_read_node;
244 		ent->write_proc = proc_write_node;
245 		ent->data = (void *)(long)(node->handle + 0x100);
246 		return 0;
247 	}
248 
249 	return -EIO;
250 }
251 
252 /*
253  * When this is called, pnpbios functions are assumed to
254  * work and the pnpbios_dont_use_current_config flag
255  * should already have been set to the appropriate value
256  */
257 int __init pnpbios_proc_init(void)
258 {
259 	proc_pnp = proc_mkdir("bus/pnp", NULL);
260 	if (!proc_pnp)
261 		return -EIO;
262 	proc_pnp_boot = proc_mkdir("boot", proc_pnp);
263 	if (!proc_pnp_boot)
264 		return -EIO;
265 	create_proc_read_entry("devices", 0, proc_pnp, proc_read_devices, NULL);
266 	create_proc_read_entry("configuration_info", 0, proc_pnp,
267 			       proc_read_pnpconfig, NULL);
268 	create_proc_read_entry("escd_info", 0, proc_pnp, proc_read_escdinfo,
269 			       NULL);
270 	create_proc_read_entry("escd", S_IRUSR, proc_pnp, proc_read_escd, NULL);
271 	create_proc_read_entry("legacy_device_resources", 0, proc_pnp,
272 			       proc_read_legacyres, NULL);
273 
274 	return 0;
275 }
276 
277 void __exit pnpbios_proc_exit(void)
278 {
279 	int i;
280 	char name[3];
281 
282 	if (!proc_pnp)
283 		return;
284 
285 	for (i = 0; i < 0xff; i++) {
286 		sprintf(name, "%02x", i);
287 		if (!pnpbios_dont_use_current_config)
288 			remove_proc_entry(name, proc_pnp);
289 		remove_proc_entry(name, proc_pnp_boot);
290 	}
291 	remove_proc_entry("legacy_device_resources", proc_pnp);
292 	remove_proc_entry("escd", proc_pnp);
293 	remove_proc_entry("escd_info", proc_pnp);
294 	remove_proc_entry("configuration_info", proc_pnp);
295 	remove_proc_entry("devices", proc_pnp);
296 	remove_proc_entry("boot", proc_pnp);
297 	remove_proc_entry("bus/pnp", NULL);
298 }
299