xref: /openbmc/linux/drivers/scsi/scsi_proc.c (revision 5e012745)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/drivers/scsi/scsi_proc.c
4  *
5  * The functions in this file provide an interface between
6  * the PROC file system and the SCSI device drivers
7  * It is mainly used for debugging, statistics and to pass
8  * information directly to the lowlevel driver.
9  *
10  * (c) 1995 Michael Neuffer neuffer@goofy.zdv.uni-mainz.de
11  * Version: 0.99.8   last change: 95/09/13
12  *
13  * generic command parser provided by:
14  * Andreas Heilwagen <crashcar@informatik.uni-koblenz.de>
15  *
16  * generic_proc_info() support of xxxx_info() by:
17  * Michael A. Griffith <grif@acm.org>
18  */
19 
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/string.h>
23 #include <linux/mm.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 <linux/gfp.h>
30 #include <linux/uaccess.h>
31 
32 #include <scsi/scsi.h>
33 #include <scsi/scsi_device.h>
34 #include <scsi/scsi_host.h>
35 #include <scsi/scsi_transport.h>
36 
37 #include "scsi_priv.h"
38 #include "scsi_logging.h"
39 
40 
41 /* 4K page size, but our output routines, use some slack for overruns */
42 #define PROC_BLOCK_SIZE (3*1024)
43 
44 static struct proc_dir_entry *proc_scsi;
45 
46 /* Protect sht->present and sht->proc_dir */
47 static DEFINE_MUTEX(global_host_template_mutex);
48 
49 static ssize_t proc_scsi_host_write(struct file *file, const char __user *buf,
50                            size_t count, loff_t *ppos)
51 {
52 	struct Scsi_Host *shost = PDE_DATA(file_inode(file));
53 	ssize_t ret = -ENOMEM;
54 	char *page;
55 
56 	if (count > PROC_BLOCK_SIZE)
57 		return -EOVERFLOW;
58 
59 	if (!shost->hostt->write_info)
60 		return -EINVAL;
61 
62 	page = (char *)__get_free_page(GFP_KERNEL);
63 	if (page) {
64 		ret = -EFAULT;
65 		if (copy_from_user(page, buf, count))
66 			goto out;
67 		ret = shost->hostt->write_info(shost, page, count);
68 	}
69 out:
70 	free_page((unsigned long)page);
71 	return ret;
72 }
73 
74 static int proc_scsi_show(struct seq_file *m, void *v)
75 {
76 	struct Scsi_Host *shost = m->private;
77 	return shost->hostt->show_info(m, shost);
78 }
79 
80 static int proc_scsi_host_open(struct inode *inode, struct file *file)
81 {
82 	return single_open_size(file, proc_scsi_show, PDE_DATA(inode),
83 				4 * PAGE_SIZE);
84 }
85 
86 static const struct file_operations proc_scsi_fops = {
87 	.open = proc_scsi_host_open,
88 	.release = single_release,
89 	.read = seq_read,
90 	.llseek = seq_lseek,
91 	.write = proc_scsi_host_write
92 };
93 
94 /**
95  * scsi_proc_hostdir_add - Create directory in /proc for a scsi host
96  * @sht: owner of this directory
97  *
98  * Sets sht->proc_dir to the new directory.
99  */
100 
101 void scsi_proc_hostdir_add(struct scsi_host_template *sht)
102 {
103 	if (!sht->show_info)
104 		return;
105 
106 	mutex_lock(&global_host_template_mutex);
107 	if (!sht->present++) {
108 		sht->proc_dir = proc_mkdir(sht->proc_name, proc_scsi);
109         	if (!sht->proc_dir)
110 			printk(KERN_ERR "%s: proc_mkdir failed for %s\n",
111 			       __func__, sht->proc_name);
112 	}
113 	mutex_unlock(&global_host_template_mutex);
114 }
115 
116 /**
117  * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
118  * @sht: owner of directory
119  */
120 void scsi_proc_hostdir_rm(struct scsi_host_template *sht)
121 {
122 	if (!sht->show_info)
123 		return;
124 
125 	mutex_lock(&global_host_template_mutex);
126 	if (!--sht->present && sht->proc_dir) {
127 		remove_proc_entry(sht->proc_name, proc_scsi);
128 		sht->proc_dir = NULL;
129 	}
130 	mutex_unlock(&global_host_template_mutex);
131 }
132 
133 
134 /**
135  * scsi_proc_host_add - Add entry for this host to appropriate /proc dir
136  * @shost: host to add
137  */
138 void scsi_proc_host_add(struct Scsi_Host *shost)
139 {
140 	struct scsi_host_template *sht = shost->hostt;
141 	struct proc_dir_entry *p;
142 	char name[10];
143 
144 	if (!sht->proc_dir)
145 		return;
146 
147 	sprintf(name,"%d", shost->host_no);
148 	p = proc_create_data(name, S_IRUGO | S_IWUSR,
149 		sht->proc_dir, &proc_scsi_fops, shost);
150 	if (!p)
151 		printk(KERN_ERR "%s: Failed to register host %d in"
152 		       "%s\n", __func__, shost->host_no,
153 		       sht->proc_name);
154 }
155 
156 /**
157  * scsi_proc_host_rm - remove this host's entry from /proc
158  * @shost: which host
159  */
160 void scsi_proc_host_rm(struct Scsi_Host *shost)
161 {
162 	char name[10];
163 
164 	if (!shost->hostt->proc_dir)
165 		return;
166 
167 	sprintf(name,"%d", shost->host_no);
168 	remove_proc_entry(name, shost->hostt->proc_dir);
169 }
170 /**
171  * proc_print_scsidevice - return data about this host
172  * @dev: A scsi device
173  * @data: &struct seq_file to output to.
174  *
175  * Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
176  * and revision.
177  */
178 static int proc_print_scsidevice(struct device *dev, void *data)
179 {
180 	struct scsi_device *sdev;
181 	struct seq_file *s = data;
182 	int i;
183 
184 	if (!scsi_is_sdev_device(dev))
185 		goto out;
186 
187 	sdev = to_scsi_device(dev);
188 	seq_printf(s,
189 		"Host: scsi%d Channel: %02d Id: %02d Lun: %02llu\n  Vendor: ",
190 		sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
191 	for (i = 0; i < 8; i++) {
192 		if (sdev->vendor[i] >= 0x20)
193 			seq_putc(s, sdev->vendor[i]);
194 		else
195 			seq_putc(s, ' ');
196 	}
197 
198 	seq_puts(s, " Model: ");
199 	for (i = 0; i < 16; i++) {
200 		if (sdev->model[i] >= 0x20)
201 			seq_putc(s, sdev->model[i]);
202 		else
203 			seq_putc(s, ' ');
204 	}
205 
206 	seq_puts(s, " Rev: ");
207 	for (i = 0; i < 4; i++) {
208 		if (sdev->rev[i] >= 0x20)
209 			seq_putc(s, sdev->rev[i]);
210 		else
211 			seq_putc(s, ' ');
212 	}
213 
214 	seq_putc(s, '\n');
215 
216 	seq_printf(s, "  Type:   %s ", scsi_device_type(sdev->type));
217 	seq_printf(s, "               ANSI  SCSI revision: %02x",
218 			sdev->scsi_level - (sdev->scsi_level > 1));
219 	if (sdev->scsi_level == 2)
220 		seq_puts(s, " CCS\n");
221 	else
222 		seq_putc(s, '\n');
223 
224 out:
225 	return 0;
226 }
227 
228 /**
229  * scsi_add_single_device - Respond to user request to probe for/add device
230  * @host: user-supplied decimal integer
231  * @channel: user-supplied decimal integer
232  * @id: user-supplied decimal integer
233  * @lun: user-supplied decimal integer
234  *
235  * Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
236  *
237  * does scsi_host_lookup() and either user_scan() if that transport
238  * type supports it, or else scsi_scan_host_selected()
239  *
240  * Note: this seems to be aimed exclusively at SCSI parallel busses.
241  */
242 
243 static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
244 {
245 	struct Scsi_Host *shost;
246 	int error = -ENXIO;
247 
248 	shost = scsi_host_lookup(host);
249 	if (!shost)
250 		return error;
251 
252 	if (shost->transportt->user_scan)
253 		error = shost->transportt->user_scan(shost, channel, id, lun);
254 	else
255 		error = scsi_scan_host_selected(shost, channel, id, lun,
256 						SCSI_SCAN_MANUAL);
257 	scsi_host_put(shost);
258 	return error;
259 }
260 
261 /**
262  * scsi_remove_single_device - Respond to user request to remove a device
263  * @host: user-supplied decimal integer
264  * @channel: user-supplied decimal integer
265  * @id: user-supplied decimal integer
266  * @lun: user-supplied decimal integer
267  *
268  * Description: called by writing "scsi remove-single-device" to
269  * /proc/scsi/scsi.  Does a scsi_device_lookup() and scsi_remove_device()
270  */
271 static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
272 {
273 	struct scsi_device *sdev;
274 	struct Scsi_Host *shost;
275 	int error = -ENXIO;
276 
277 	shost = scsi_host_lookup(host);
278 	if (!shost)
279 		return error;
280 	sdev = scsi_device_lookup(shost, channel, id, lun);
281 	if (sdev) {
282 		scsi_remove_device(sdev);
283 		scsi_device_put(sdev);
284 		error = 0;
285 	}
286 
287 	scsi_host_put(shost);
288 	return error;
289 }
290 
291 /**
292  * proc_scsi_write - handle writes to /proc/scsi/scsi
293  * @file: not used
294  * @buf: buffer to write
295  * @length: length of buf, at most PAGE_SIZE
296  * @ppos: not used
297  *
298  * Description: this provides a legacy mechanism to add or remove devices by
299  * Host, Channel, ID, and Lun.  To use,
300  * "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
301  * "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
302  * "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
303  *
304  * Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
305  * SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
306  * provide a unique identifier and nothing more.
307  */
308 
309 
310 static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
311 			       size_t length, loff_t *ppos)
312 {
313 	int host, channel, id, lun;
314 	char *buffer, *p;
315 	int err;
316 
317 	if (!buf || length > PAGE_SIZE)
318 		return -EINVAL;
319 
320 	buffer = (char *)__get_free_page(GFP_KERNEL);
321 	if (!buffer)
322 		return -ENOMEM;
323 
324 	err = -EFAULT;
325 	if (copy_from_user(buffer, buf, length))
326 		goto out;
327 
328 	err = -EINVAL;
329 	if (length < PAGE_SIZE)
330 		buffer[length] = '\0';
331 	else if (buffer[PAGE_SIZE-1])
332 		goto out;
333 
334 	/*
335 	 * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
336 	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
337 	 */
338 	if (!strncmp("scsi add-single-device", buffer, 22)) {
339 		p = buffer + 23;
340 
341 		host = simple_strtoul(p, &p, 0);
342 		channel = simple_strtoul(p + 1, &p, 0);
343 		id = simple_strtoul(p + 1, &p, 0);
344 		lun = simple_strtoul(p + 1, &p, 0);
345 
346 		err = scsi_add_single_device(host, channel, id, lun);
347 
348 	/*
349 	 * Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
350 	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
351 	 */
352 	} else if (!strncmp("scsi remove-single-device", buffer, 25)) {
353 		p = buffer + 26;
354 
355 		host = simple_strtoul(p, &p, 0);
356 		channel = simple_strtoul(p + 1, &p, 0);
357 		id = simple_strtoul(p + 1, &p, 0);
358 		lun = simple_strtoul(p + 1, &p, 0);
359 
360 		err = scsi_remove_single_device(host, channel, id, lun);
361 	}
362 
363 	/*
364 	 * convert success returns so that we return the
365 	 * number of bytes consumed.
366 	 */
367 	if (!err)
368 		err = length;
369 
370  out:
371 	free_page((unsigned long)buffer);
372 	return err;
373 }
374 
375 static int always_match(struct device *dev, const void *data)
376 {
377 	return 1;
378 }
379 
380 static inline struct device *next_scsi_device(struct device *start)
381 {
382 	struct device *next = bus_find_device(&scsi_bus_type, start, NULL,
383 					      always_match);
384 	put_device(start);
385 	return next;
386 }
387 
388 static void *scsi_seq_start(struct seq_file *sfile, loff_t *pos)
389 {
390 	struct device *dev = NULL;
391 	loff_t n = *pos;
392 
393 	while ((dev = next_scsi_device(dev))) {
394 		if (!n--)
395 			break;
396 		sfile->private++;
397 	}
398 	return dev;
399 }
400 
401 static void *scsi_seq_next(struct seq_file *sfile, void *v, loff_t *pos)
402 {
403 	(*pos)++;
404 	sfile->private++;
405 	return next_scsi_device(v);
406 }
407 
408 static void scsi_seq_stop(struct seq_file *sfile, void *v)
409 {
410 	put_device(v);
411 }
412 
413 static int scsi_seq_show(struct seq_file *sfile, void *dev)
414 {
415 	if (!sfile->private)
416 		seq_puts(sfile, "Attached devices:\n");
417 
418 	return proc_print_scsidevice(dev, sfile);
419 }
420 
421 static const struct seq_operations scsi_seq_ops = {
422 	.start	= scsi_seq_start,
423 	.next	= scsi_seq_next,
424 	.stop	= scsi_seq_stop,
425 	.show	= scsi_seq_show
426 };
427 
428 /**
429  * proc_scsi_open - glue function
430  * @inode: not used
431  * @file: passed to single_open()
432  *
433  * Associates proc_scsi_show with this file
434  */
435 static int proc_scsi_open(struct inode *inode, struct file *file)
436 {
437 	/*
438 	 * We don't really need this for the write case but it doesn't
439 	 * harm either.
440 	 */
441 	return seq_open(file, &scsi_seq_ops);
442 }
443 
444 static const struct file_operations proc_scsi_operations = {
445 	.owner		= THIS_MODULE,
446 	.open		= proc_scsi_open,
447 	.read		= seq_read,
448 	.write		= proc_scsi_write,
449 	.llseek		= seq_lseek,
450 	.release	= seq_release,
451 };
452 
453 /**
454  * scsi_init_procfs - create scsi and scsi/scsi in procfs
455  */
456 int __init scsi_init_procfs(void)
457 {
458 	struct proc_dir_entry *pde;
459 
460 	proc_scsi = proc_mkdir("scsi", NULL);
461 	if (!proc_scsi)
462 		goto err1;
463 
464 	pde = proc_create("scsi/scsi", 0, NULL, &proc_scsi_operations);
465 	if (!pde)
466 		goto err2;
467 
468 	return 0;
469 
470 err2:
471 	remove_proc_entry("scsi", NULL);
472 err1:
473 	return -ENOMEM;
474 }
475 
476 /**
477  * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
478  */
479 void scsi_exit_procfs(void)
480 {
481 	remove_proc_entry("scsi/scsi", NULL);
482 	remove_proc_entry("scsi", NULL);
483 }
484