xref: /openbmc/linux/drivers/scsi/scsi_proc.c (revision 384740dc)
1 /*
2  * linux/drivers/scsi/scsi_proc.c
3  *
4  * The functions in this file provide an interface between
5  * the PROC file system and the SCSI device drivers
6  * It is mainly used for debugging, statistics and to pass
7  * information directly to the lowlevel driver.
8  *
9  * (c) 1995 Michael Neuffer neuffer@goofy.zdv.uni-mainz.de
10  * Version: 0.99.8   last change: 95/09/13
11  *
12  * generic command parser provided by:
13  * Andreas Heilwagen <crashcar@informatik.uni-koblenz.de>
14  *
15  * generic_proc_info() support of xxxx_info() by:
16  * Michael A. Griffith <grif@acm.org>
17  */
18 
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/string.h>
22 #include <linux/mm.h>
23 #include <linux/slab.h>
24 #include <linux/proc_fs.h>
25 #include <linux/errno.h>
26 #include <linux/blkdev.h>
27 #include <linux/seq_file.h>
28 #include <linux/mutex.h>
29 #include <asm/uaccess.h>
30 
31 #include <scsi/scsi.h>
32 #include <scsi/scsi_device.h>
33 #include <scsi/scsi_host.h>
34 #include <scsi/scsi_transport.h>
35 
36 #include "scsi_priv.h"
37 #include "scsi_logging.h"
38 
39 
40 /* 4K page size, but our output routines, use some slack for overruns */
41 #define PROC_BLOCK_SIZE (3*1024)
42 
43 static struct proc_dir_entry *proc_scsi;
44 
45 /* Protect sht->present and sht->proc_dir */
46 static DEFINE_MUTEX(global_host_template_mutex);
47 
48 /**
49  * proc_scsi_read - handle read from /proc by calling host's proc_info() command
50  * @buffer: passed to proc_info
51  * @start: passed to proc_info
52  * @offset: passed to proc_info
53  * @length: passed to proc_info
54  * @eof: returns whether length read was less than requested
55  * @data: pointer to a &struct Scsi_Host
56  */
57 
58 static int proc_scsi_read(char *buffer, char **start, off_t offset,
59 			  int length, int *eof, void *data)
60 {
61 	struct Scsi_Host *shost = data;
62 	int n;
63 
64 	n = shost->hostt->proc_info(shost, buffer, start, offset, length, 0);
65 	*eof = (n < length);
66 
67 	return n;
68 }
69 
70 /**
71  * proc_scsi_write_proc - Handle write to /proc by calling host's proc_info()
72  * @file: not used
73  * @buf: source of data to write.
74  * @count: number of bytes (at most PROC_BLOCK_SIZE) to write.
75  * @data: pointer to &struct Scsi_Host
76  */
77 static int proc_scsi_write_proc(struct file *file, const char __user *buf,
78                            unsigned long count, void *data)
79 {
80 	struct Scsi_Host *shost = data;
81 	ssize_t ret = -ENOMEM;
82 	char *page;
83 	char *start;
84 
85 	if (count > PROC_BLOCK_SIZE)
86 		return -EOVERFLOW;
87 
88 	page = (char *)__get_free_page(GFP_KERNEL);
89 	if (page) {
90 		ret = -EFAULT;
91 		if (copy_from_user(page, buf, count))
92 			goto out;
93 		ret = shost->hostt->proc_info(shost, page, &start, 0, count, 1);
94 	}
95 out:
96 	free_page((unsigned long)page);
97 	return ret;
98 }
99 
100 /**
101  * scsi_proc_hostdir_add - Create directory in /proc for a scsi host
102  * @sht: owner of this directory
103  *
104  * Sets sht->proc_dir to the new directory.
105  */
106 
107 void scsi_proc_hostdir_add(struct scsi_host_template *sht)
108 {
109 	if (!sht->proc_info)
110 		return;
111 
112 	mutex_lock(&global_host_template_mutex);
113 	if (!sht->present++) {
114 		sht->proc_dir = proc_mkdir(sht->proc_name, proc_scsi);
115         	if (!sht->proc_dir)
116 			printk(KERN_ERR "%s: proc_mkdir failed for %s\n",
117 			       __func__, sht->proc_name);
118 		else
119 			sht->proc_dir->owner = sht->module;
120 	}
121 	mutex_unlock(&global_host_template_mutex);
122 }
123 
124 /**
125  * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
126  * @sht: owner of directory
127  */
128 void scsi_proc_hostdir_rm(struct scsi_host_template *sht)
129 {
130 	if (!sht->proc_info)
131 		return;
132 
133 	mutex_lock(&global_host_template_mutex);
134 	if (!--sht->present && sht->proc_dir) {
135 		remove_proc_entry(sht->proc_name, proc_scsi);
136 		sht->proc_dir = NULL;
137 	}
138 	mutex_unlock(&global_host_template_mutex);
139 }
140 
141 
142 /**
143  * scsi_proc_host_add - Add entry for this host to appropriate /proc dir
144  * @shost: host to add
145  */
146 void scsi_proc_host_add(struct Scsi_Host *shost)
147 {
148 	struct scsi_host_template *sht = shost->hostt;
149 	struct proc_dir_entry *p;
150 	char name[10];
151 
152 	if (!sht->proc_dir)
153 		return;
154 
155 	sprintf(name,"%d", shost->host_no);
156 	p = create_proc_read_entry(name, S_IFREG | S_IRUGO | S_IWUSR,
157 			sht->proc_dir, proc_scsi_read, shost);
158 	if (!p) {
159 		printk(KERN_ERR "%s: Failed to register host %d in"
160 		       "%s\n", __func__, shost->host_no,
161 		       sht->proc_name);
162 		return;
163 	}
164 
165 	p->write_proc = proc_scsi_write_proc;
166 	p->owner = sht->module;
167 }
168 
169 /**
170  * scsi_proc_host_rm - remove this host's entry from /proc
171  * @shost: which host
172  */
173 void scsi_proc_host_rm(struct Scsi_Host *shost)
174 {
175 	char name[10];
176 
177 	if (!shost->hostt->proc_dir)
178 		return;
179 
180 	sprintf(name,"%d", shost->host_no);
181 	remove_proc_entry(name, shost->hostt->proc_dir);
182 }
183 /**
184  * proc_print_scsidevice - return data about this host
185  * @dev: A scsi device
186  * @data: &struct seq_file to output to.
187  *
188  * Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
189  * and revision.
190  */
191 static int proc_print_scsidevice(struct device *dev, void *data)
192 {
193 	struct scsi_device *sdev;
194 	struct seq_file *s = data;
195 	int i;
196 
197 	if (!scsi_is_sdev_device(dev))
198 		goto out;
199 
200 	sdev = to_scsi_device(dev);
201 	seq_printf(s,
202 		"Host: scsi%d Channel: %02d Id: %02d Lun: %02d\n  Vendor: ",
203 		sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
204 	for (i = 0; i < 8; i++) {
205 		if (sdev->vendor[i] >= 0x20)
206 			seq_printf(s, "%c", sdev->vendor[i]);
207 		else
208 			seq_printf(s, " ");
209 	}
210 
211 	seq_printf(s, " Model: ");
212 	for (i = 0; i < 16; i++) {
213 		if (sdev->model[i] >= 0x20)
214 			seq_printf(s, "%c", sdev->model[i]);
215 		else
216 			seq_printf(s, " ");
217 	}
218 
219 	seq_printf(s, " Rev: ");
220 	for (i = 0; i < 4; i++) {
221 		if (sdev->rev[i] >= 0x20)
222 			seq_printf(s, "%c", sdev->rev[i]);
223 		else
224 			seq_printf(s, " ");
225 	}
226 
227 	seq_printf(s, "\n");
228 
229 	seq_printf(s, "  Type:   %s ", scsi_device_type(sdev->type));
230 	seq_printf(s, "               ANSI  SCSI revision: %02x",
231 			sdev->scsi_level - (sdev->scsi_level > 1));
232 	if (sdev->scsi_level == 2)
233 		seq_printf(s, " CCS\n");
234 	else
235 		seq_printf(s, "\n");
236 
237 out:
238 	return 0;
239 }
240 
241 /**
242  * scsi_add_single_device - Respond to user request to probe for/add device
243  * @host: user-supplied decimal integer
244  * @channel: user-supplied decimal integer
245  * @id: user-supplied decimal integer
246  * @lun: user-supplied decimal integer
247  *
248  * Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
249  *
250  * does scsi_host_lookup() and either user_scan() if that transport
251  * type supports it, or else scsi_scan_host_selected()
252  *
253  * Note: this seems to be aimed exclusively at SCSI parallel busses.
254  */
255 
256 static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
257 {
258 	struct Scsi_Host *shost;
259 	int error = -ENXIO;
260 
261 	shost = scsi_host_lookup(host);
262 	if (!shost)
263 		return error;
264 
265 	if (shost->transportt->user_scan)
266 		error = shost->transportt->user_scan(shost, channel, id, lun);
267 	else
268 		error = scsi_scan_host_selected(shost, channel, id, lun, 1);
269 	scsi_host_put(shost);
270 	return error;
271 }
272 
273 /**
274  * scsi_remove_single_device - Respond to user request to remove a device
275  * @host: user-supplied decimal integer
276  * @channel: user-supplied decimal integer
277  * @id: user-supplied decimal integer
278  * @lun: user-supplied decimal integer
279  *
280  * Description: called by writing "scsi remove-single-device" to
281  * /proc/scsi/scsi.  Does a scsi_device_lookup() and scsi_remove_device()
282  */
283 static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
284 {
285 	struct scsi_device *sdev;
286 	struct Scsi_Host *shost;
287 	int error = -ENXIO;
288 
289 	shost = scsi_host_lookup(host);
290 	if (!shost)
291 		return error;
292 	sdev = scsi_device_lookup(shost, channel, id, lun);
293 	if (sdev) {
294 		scsi_remove_device(sdev);
295 		scsi_device_put(sdev);
296 		error = 0;
297 	}
298 
299 	scsi_host_put(shost);
300 	return error;
301 }
302 
303 /**
304  * proc_scsi_write - handle writes to /proc/scsi/scsi
305  * @file: not used
306  * @buf: buffer to write
307  * @length: length of buf, at most PAGE_SIZE
308  * @ppos: not used
309  *
310  * Description: this provides a legacy mechanism to add or remove devices by
311  * Host, Channel, ID, and Lun.  To use,
312  * "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
313  * "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
314  * "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
315  *
316  * Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
317  * SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
318  * provide a unique identifier and nothing more.
319  */
320 
321 
322 static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
323 			       size_t length, loff_t *ppos)
324 {
325 	int host, channel, id, lun;
326 	char *buffer, *p;
327 	int err;
328 
329 	if (!buf || length > PAGE_SIZE)
330 		return -EINVAL;
331 
332 	buffer = (char *)__get_free_page(GFP_KERNEL);
333 	if (!buffer)
334 		return -ENOMEM;
335 
336 	err = -EFAULT;
337 	if (copy_from_user(buffer, buf, length))
338 		goto out;
339 
340 	err = -EINVAL;
341 	if (length < PAGE_SIZE)
342 		buffer[length] = '\0';
343 	else if (buffer[PAGE_SIZE-1])
344 		goto out;
345 
346 	/*
347 	 * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
348 	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
349 	 */
350 	if (!strncmp("scsi add-single-device", buffer, 22)) {
351 		p = buffer + 23;
352 
353 		host = simple_strtoul(p, &p, 0);
354 		channel = simple_strtoul(p + 1, &p, 0);
355 		id = simple_strtoul(p + 1, &p, 0);
356 		lun = simple_strtoul(p + 1, &p, 0);
357 
358 		err = scsi_add_single_device(host, channel, id, lun);
359 
360 	/*
361 	 * Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
362 	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
363 	 */
364 	} else if (!strncmp("scsi remove-single-device", buffer, 25)) {
365 		p = buffer + 26;
366 
367 		host = simple_strtoul(p, &p, 0);
368 		channel = simple_strtoul(p + 1, &p, 0);
369 		id = simple_strtoul(p + 1, &p, 0);
370 		lun = simple_strtoul(p + 1, &p, 0);
371 
372 		err = scsi_remove_single_device(host, channel, id, lun);
373 	}
374 
375 	/*
376 	 * convert success returns so that we return the
377 	 * number of bytes consumed.
378 	 */
379 	if (!err)
380 		err = length;
381 
382  out:
383 	free_page((unsigned long)buffer);
384 	return err;
385 }
386 
387 /**
388  * proc_scsi_show - show contents of /proc/scsi/scsi (attached devices)
389  * @s: output goes here
390  * @p: not used
391  */
392 static int proc_scsi_show(struct seq_file *s, void *p)
393 {
394 	seq_printf(s, "Attached devices:\n");
395 	bus_for_each_dev(&scsi_bus_type, NULL, s, proc_print_scsidevice);
396 	return 0;
397 }
398 
399 /**
400  * proc_scsi_open - glue function
401  * @inode: not used
402  * @file: passed to single_open()
403  *
404  * Associates proc_scsi_show with this file
405  */
406 static int proc_scsi_open(struct inode *inode, struct file *file)
407 {
408 	/*
409 	 * We don't really need this for the write case but it doesn't
410 	 * harm either.
411 	 */
412 	return single_open(file, proc_scsi_show, NULL);
413 }
414 
415 static const struct file_operations proc_scsi_operations = {
416 	.owner		= THIS_MODULE,
417 	.open		= proc_scsi_open,
418 	.read		= seq_read,
419 	.write		= proc_scsi_write,
420 	.llseek		= seq_lseek,
421 	.release	= single_release,
422 };
423 
424 /**
425  * scsi_init_procfs - create scsi and scsi/scsi in procfs
426  */
427 int __init scsi_init_procfs(void)
428 {
429 	struct proc_dir_entry *pde;
430 
431 	proc_scsi = proc_mkdir("scsi", NULL);
432 	if (!proc_scsi)
433 		goto err1;
434 
435 	pde = proc_create("scsi/scsi", 0, NULL, &proc_scsi_operations);
436 	if (!pde)
437 		goto err2;
438 
439 	return 0;
440 
441 err2:
442 	remove_proc_entry("scsi", NULL);
443 err1:
444 	return -ENOMEM;
445 }
446 
447 /**
448  * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
449  */
450 void scsi_exit_procfs(void)
451 {
452 	remove_proc_entry("scsi/scsi", NULL);
453 	remove_proc_entry("scsi", NULL);
454 }
455