xref: /openbmc/linux/drivers/scsi/scsi_proc.c (revision 65ee8aeb)
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/proc_fs.h>
24 #include <linux/errno.h>
25 #include <linux/blkdev.h>
26 #include <linux/seq_file.h>
27 #include <linux/mutex.h>
28 #include <linux/gfp.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 static ssize_t proc_scsi_host_write(struct file *file, const char __user *buf,
49                            size_t count, loff_t *ppos)
50 {
51 	struct Scsi_Host *shost = PDE_DATA(file_inode(file));
52 	ssize_t ret = -ENOMEM;
53 	char *page;
54 
55 	if (count > PROC_BLOCK_SIZE)
56 		return -EOVERFLOW;
57 
58 	if (!shost->hostt->write_info)
59 		return -EINVAL;
60 
61 	page = (char *)__get_free_page(GFP_KERNEL);
62 	if (page) {
63 		ret = -EFAULT;
64 		if (copy_from_user(page, buf, count))
65 			goto out;
66 		ret = shost->hostt->write_info(shost, page, count);
67 	}
68 out:
69 	free_page((unsigned long)page);
70 	return ret;
71 }
72 
73 static int proc_scsi_show(struct seq_file *m, void *v)
74 {
75 	struct Scsi_Host *shost = m->private;
76 	return shost->hostt->show_info(m, shost);
77 }
78 
79 static int proc_scsi_host_open(struct inode *inode, struct file *file)
80 {
81 	return single_open_size(file, proc_scsi_show, PDE_DATA(inode),
82 				4 * PAGE_SIZE);
83 }
84 
85 static const struct file_operations proc_scsi_fops = {
86 	.open = proc_scsi_host_open,
87 	.release = single_release,
88 	.read = seq_read,
89 	.llseek = seq_lseek,
90 	.write = proc_scsi_host_write
91 };
92 
93 /**
94  * scsi_proc_hostdir_add - Create directory in /proc for a scsi host
95  * @sht: owner of this directory
96  *
97  * Sets sht->proc_dir to the new directory.
98  */
99 
100 void scsi_proc_hostdir_add(struct scsi_host_template *sht)
101 {
102 	if (!sht->show_info)
103 		return;
104 
105 	mutex_lock(&global_host_template_mutex);
106 	if (!sht->present++) {
107 		sht->proc_dir = proc_mkdir(sht->proc_name, proc_scsi);
108         	if (!sht->proc_dir)
109 			printk(KERN_ERR "%s: proc_mkdir failed for %s\n",
110 			       __func__, sht->proc_name);
111 	}
112 	mutex_unlock(&global_host_template_mutex);
113 }
114 
115 /**
116  * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
117  * @sht: owner of directory
118  */
119 void scsi_proc_hostdir_rm(struct scsi_host_template *sht)
120 {
121 	if (!sht->show_info)
122 		return;
123 
124 	mutex_lock(&global_host_template_mutex);
125 	if (!--sht->present && sht->proc_dir) {
126 		remove_proc_entry(sht->proc_name, proc_scsi);
127 		sht->proc_dir = NULL;
128 	}
129 	mutex_unlock(&global_host_template_mutex);
130 }
131 
132 
133 /**
134  * scsi_proc_host_add - Add entry for this host to appropriate /proc dir
135  * @shost: host to add
136  */
137 void scsi_proc_host_add(struct Scsi_Host *shost)
138 {
139 	struct scsi_host_template *sht = shost->hostt;
140 	struct proc_dir_entry *p;
141 	char name[10];
142 
143 	if (!sht->proc_dir)
144 		return;
145 
146 	sprintf(name,"%d", shost->host_no);
147 	p = proc_create_data(name, S_IRUGO | S_IWUSR,
148 		sht->proc_dir, &proc_scsi_fops, shost);
149 	if (!p)
150 		printk(KERN_ERR "%s: Failed to register host %d in"
151 		       "%s\n", __func__, shost->host_no,
152 		       sht->proc_name);
153 }
154 
155 /**
156  * scsi_proc_host_rm - remove this host's entry from /proc
157  * @shost: which host
158  */
159 void scsi_proc_host_rm(struct Scsi_Host *shost)
160 {
161 	char name[10];
162 
163 	if (!shost->hostt->proc_dir)
164 		return;
165 
166 	sprintf(name,"%d", shost->host_no);
167 	remove_proc_entry(name, shost->hostt->proc_dir);
168 }
169 /**
170  * proc_print_scsidevice - return data about this host
171  * @dev: A scsi device
172  * @data: &struct seq_file to output to.
173  *
174  * Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
175  * and revision.
176  */
177 static int proc_print_scsidevice(struct device *dev, void *data)
178 {
179 	struct scsi_device *sdev;
180 	struct seq_file *s = data;
181 	int i;
182 
183 	if (!scsi_is_sdev_device(dev))
184 		goto out;
185 
186 	sdev = to_scsi_device(dev);
187 	seq_printf(s,
188 		"Host: scsi%d Channel: %02d Id: %02d Lun: %02llu\n  Vendor: ",
189 		sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
190 	for (i = 0; i < 8; i++) {
191 		if (sdev->vendor[i] >= 0x20)
192 			seq_putc(s, sdev->vendor[i]);
193 		else
194 			seq_putc(s, ' ');
195 	}
196 
197 	seq_puts(s, " Model: ");
198 	for (i = 0; i < 16; i++) {
199 		if (sdev->model[i] >= 0x20)
200 			seq_putc(s, sdev->model[i]);
201 		else
202 			seq_putc(s, ' ');
203 	}
204 
205 	seq_puts(s, " Rev: ");
206 	for (i = 0; i < 4; i++) {
207 		if (sdev->rev[i] >= 0x20)
208 			seq_putc(s, sdev->rev[i]);
209 		else
210 			seq_putc(s, ' ');
211 	}
212 
213 	seq_putc(s, '\n');
214 
215 	seq_printf(s, "  Type:   %s ", scsi_device_type(sdev->type));
216 	seq_printf(s, "               ANSI  SCSI revision: %02x",
217 			sdev->scsi_level - (sdev->scsi_level > 1));
218 	if (sdev->scsi_level == 2)
219 		seq_puts(s, " CCS\n");
220 	else
221 		seq_putc(s, '\n');
222 
223 out:
224 	return 0;
225 }
226 
227 /**
228  * scsi_add_single_device - Respond to user request to probe for/add device
229  * @host: user-supplied decimal integer
230  * @channel: user-supplied decimal integer
231  * @id: user-supplied decimal integer
232  * @lun: user-supplied decimal integer
233  *
234  * Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
235  *
236  * does scsi_host_lookup() and either user_scan() if that transport
237  * type supports it, or else scsi_scan_host_selected()
238  *
239  * Note: this seems to be aimed exclusively at SCSI parallel busses.
240  */
241 
242 static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
243 {
244 	struct Scsi_Host *shost;
245 	int error = -ENXIO;
246 
247 	shost = scsi_host_lookup(host);
248 	if (!shost)
249 		return error;
250 
251 	if (shost->transportt->user_scan)
252 		error = shost->transportt->user_scan(shost, channel, id, lun);
253 	else
254 		error = scsi_scan_host_selected(shost, channel, id, lun, 1);
255 	scsi_host_put(shost);
256 	return error;
257 }
258 
259 /**
260  * scsi_remove_single_device - Respond to user request to remove a device
261  * @host: user-supplied decimal integer
262  * @channel: user-supplied decimal integer
263  * @id: user-supplied decimal integer
264  * @lun: user-supplied decimal integer
265  *
266  * Description: called by writing "scsi remove-single-device" to
267  * /proc/scsi/scsi.  Does a scsi_device_lookup() and scsi_remove_device()
268  */
269 static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
270 {
271 	struct scsi_device *sdev;
272 	struct Scsi_Host *shost;
273 	int error = -ENXIO;
274 
275 	shost = scsi_host_lookup(host);
276 	if (!shost)
277 		return error;
278 	sdev = scsi_device_lookup(shost, channel, id, lun);
279 	if (sdev) {
280 		scsi_remove_device(sdev);
281 		scsi_device_put(sdev);
282 		error = 0;
283 	}
284 
285 	scsi_host_put(shost);
286 	return error;
287 }
288 
289 /**
290  * proc_scsi_write - handle writes to /proc/scsi/scsi
291  * @file: not used
292  * @buf: buffer to write
293  * @length: length of buf, at most PAGE_SIZE
294  * @ppos: not used
295  *
296  * Description: this provides a legacy mechanism to add or remove devices by
297  * Host, Channel, ID, and Lun.  To use,
298  * "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
299  * "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
300  * "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
301  *
302  * Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
303  * SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
304  * provide a unique identifier and nothing more.
305  */
306 
307 
308 static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
309 			       size_t length, loff_t *ppos)
310 {
311 	int host, channel, id, lun;
312 	char *buffer, *p;
313 	int err;
314 
315 	if (!buf || length > PAGE_SIZE)
316 		return -EINVAL;
317 
318 	buffer = (char *)__get_free_page(GFP_KERNEL);
319 	if (!buffer)
320 		return -ENOMEM;
321 
322 	err = -EFAULT;
323 	if (copy_from_user(buffer, buf, length))
324 		goto out;
325 
326 	err = -EINVAL;
327 	if (length < PAGE_SIZE)
328 		buffer[length] = '\0';
329 	else if (buffer[PAGE_SIZE-1])
330 		goto out;
331 
332 	/*
333 	 * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
334 	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
335 	 */
336 	if (!strncmp("scsi add-single-device", buffer, 22)) {
337 		p = buffer + 23;
338 
339 		host = simple_strtoul(p, &p, 0);
340 		channel = simple_strtoul(p + 1, &p, 0);
341 		id = simple_strtoul(p + 1, &p, 0);
342 		lun = simple_strtoul(p + 1, &p, 0);
343 
344 		err = scsi_add_single_device(host, channel, id, lun);
345 
346 	/*
347 	 * Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
348 	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
349 	 */
350 	} else if (!strncmp("scsi remove-single-device", buffer, 25)) {
351 		p = buffer + 26;
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_remove_single_device(host, channel, id, lun);
359 	}
360 
361 	/*
362 	 * convert success returns so that we return the
363 	 * number of bytes consumed.
364 	 */
365 	if (!err)
366 		err = length;
367 
368  out:
369 	free_page((unsigned long)buffer);
370 	return err;
371 }
372 
373 static int always_match(struct device *dev, void *data)
374 {
375 	return 1;
376 }
377 
378 static inline struct device *next_scsi_device(struct device *start)
379 {
380 	struct device *next = bus_find_device(&scsi_bus_type, start, NULL,
381 					      always_match);
382 	put_device(start);
383 	return next;
384 }
385 
386 static void *scsi_seq_start(struct seq_file *sfile, loff_t *pos)
387 {
388 	struct device *dev = NULL;
389 	loff_t n = *pos;
390 
391 	while ((dev = next_scsi_device(dev))) {
392 		if (!n--)
393 			break;
394 		sfile->private++;
395 	}
396 	return dev;
397 }
398 
399 static void *scsi_seq_next(struct seq_file *sfile, void *v, loff_t *pos)
400 {
401 	(*pos)++;
402 	sfile->private++;
403 	return next_scsi_device(v);
404 }
405 
406 static void scsi_seq_stop(struct seq_file *sfile, void *v)
407 {
408 	put_device(v);
409 }
410 
411 static int scsi_seq_show(struct seq_file *sfile, void *dev)
412 {
413 	if (!sfile->private)
414 		seq_puts(sfile, "Attached devices:\n");
415 
416 	return proc_print_scsidevice(dev, sfile);
417 }
418 
419 static const struct seq_operations scsi_seq_ops = {
420 	.start	= scsi_seq_start,
421 	.next	= scsi_seq_next,
422 	.stop	= scsi_seq_stop,
423 	.show	= scsi_seq_show
424 };
425 
426 /**
427  * proc_scsi_open - glue function
428  * @inode: not used
429  * @file: passed to single_open()
430  *
431  * Associates proc_scsi_show with this file
432  */
433 static int proc_scsi_open(struct inode *inode, struct file *file)
434 {
435 	/*
436 	 * We don't really need this for the write case but it doesn't
437 	 * harm either.
438 	 */
439 	return seq_open(file, &scsi_seq_ops);
440 }
441 
442 static const struct file_operations proc_scsi_operations = {
443 	.owner		= THIS_MODULE,
444 	.open		= proc_scsi_open,
445 	.read		= seq_read,
446 	.write		= proc_scsi_write,
447 	.llseek		= seq_lseek,
448 	.release	= seq_release,
449 };
450 
451 /**
452  * scsi_init_procfs - create scsi and scsi/scsi in procfs
453  */
454 int __init scsi_init_procfs(void)
455 {
456 	struct proc_dir_entry *pde;
457 
458 	proc_scsi = proc_mkdir("scsi", NULL);
459 	if (!proc_scsi)
460 		goto err1;
461 
462 	pde = proc_create("scsi/scsi", 0, NULL, &proc_scsi_operations);
463 	if (!pde)
464 		goto err2;
465 
466 	return 0;
467 
468 err2:
469 	remove_proc_entry("scsi", NULL);
470 err1:
471 	return -ENOMEM;
472 }
473 
474 /**
475  * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
476  */
477 void scsi_exit_procfs(void)
478 {
479 	remove_proc_entry("scsi/scsi", NULL);
480 	remove_proc_entry("scsi", NULL);
481 }
482