xref: /openbmc/linux/drivers/scsi/scsi_proc.c (revision 63dc02bd)
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 /**
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 	}
119 	mutex_unlock(&global_host_template_mutex);
120 }
121 
122 /**
123  * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
124  * @sht: owner of directory
125  */
126 void scsi_proc_hostdir_rm(struct scsi_host_template *sht)
127 {
128 	if (!sht->proc_info)
129 		return;
130 
131 	mutex_lock(&global_host_template_mutex);
132 	if (!--sht->present && sht->proc_dir) {
133 		remove_proc_entry(sht->proc_name, proc_scsi);
134 		sht->proc_dir = NULL;
135 	}
136 	mutex_unlock(&global_host_template_mutex);
137 }
138 
139 
140 /**
141  * scsi_proc_host_add - Add entry for this host to appropriate /proc dir
142  * @shost: host to add
143  */
144 void scsi_proc_host_add(struct Scsi_Host *shost)
145 {
146 	struct scsi_host_template *sht = shost->hostt;
147 	struct proc_dir_entry *p;
148 	char name[10];
149 
150 	if (!sht->proc_dir)
151 		return;
152 
153 	sprintf(name,"%d", shost->host_no);
154 	p = create_proc_read_entry(name, S_IFREG | S_IRUGO | S_IWUSR,
155 			sht->proc_dir, proc_scsi_read, shost);
156 	if (!p) {
157 		printk(KERN_ERR "%s: Failed to register host %d in"
158 		       "%s\n", __func__, shost->host_no,
159 		       sht->proc_name);
160 		return;
161 	}
162 
163 	p->write_proc = proc_scsi_write_proc;
164 }
165 
166 /**
167  * scsi_proc_host_rm - remove this host's entry from /proc
168  * @shost: which host
169  */
170 void scsi_proc_host_rm(struct Scsi_Host *shost)
171 {
172 	char name[10];
173 
174 	if (!shost->hostt->proc_dir)
175 		return;
176 
177 	sprintf(name,"%d", shost->host_no);
178 	remove_proc_entry(name, shost->hostt->proc_dir);
179 }
180 /**
181  * proc_print_scsidevice - return data about this host
182  * @dev: A scsi device
183  * @data: &struct seq_file to output to.
184  *
185  * Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
186  * and revision.
187  */
188 static int proc_print_scsidevice(struct device *dev, void *data)
189 {
190 	struct scsi_device *sdev;
191 	struct seq_file *s = data;
192 	int i;
193 
194 	if (!scsi_is_sdev_device(dev))
195 		goto out;
196 
197 	sdev = to_scsi_device(dev);
198 	seq_printf(s,
199 		"Host: scsi%d Channel: %02d Id: %02d Lun: %02d\n  Vendor: ",
200 		sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
201 	for (i = 0; i < 8; i++) {
202 		if (sdev->vendor[i] >= 0x20)
203 			seq_printf(s, "%c", sdev->vendor[i]);
204 		else
205 			seq_printf(s, " ");
206 	}
207 
208 	seq_printf(s, " Model: ");
209 	for (i = 0; i < 16; i++) {
210 		if (sdev->model[i] >= 0x20)
211 			seq_printf(s, "%c", sdev->model[i]);
212 		else
213 			seq_printf(s, " ");
214 	}
215 
216 	seq_printf(s, " Rev: ");
217 	for (i = 0; i < 4; i++) {
218 		if (sdev->rev[i] >= 0x20)
219 			seq_printf(s, "%c", sdev->rev[i]);
220 		else
221 			seq_printf(s, " ");
222 	}
223 
224 	seq_printf(s, "\n");
225 
226 	seq_printf(s, "  Type:   %s ", scsi_device_type(sdev->type));
227 	seq_printf(s, "               ANSI  SCSI revision: %02x",
228 			sdev->scsi_level - (sdev->scsi_level > 1));
229 	if (sdev->scsi_level == 2)
230 		seq_printf(s, " CCS\n");
231 	else
232 		seq_printf(s, "\n");
233 
234 out:
235 	return 0;
236 }
237 
238 /**
239  * scsi_add_single_device - Respond to user request to probe for/add device
240  * @host: user-supplied decimal integer
241  * @channel: user-supplied decimal integer
242  * @id: user-supplied decimal integer
243  * @lun: user-supplied decimal integer
244  *
245  * Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
246  *
247  * does scsi_host_lookup() and either user_scan() if that transport
248  * type supports it, or else scsi_scan_host_selected()
249  *
250  * Note: this seems to be aimed exclusively at SCSI parallel busses.
251  */
252 
253 static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
254 {
255 	struct Scsi_Host *shost;
256 	int error = -ENXIO;
257 
258 	shost = scsi_host_lookup(host);
259 	if (!shost)
260 		return error;
261 
262 	if (shost->transportt->user_scan)
263 		error = shost->transportt->user_scan(shost, channel, id, lun);
264 	else
265 		error = scsi_scan_host_selected(shost, channel, id, lun, 1);
266 	scsi_host_put(shost);
267 	return error;
268 }
269 
270 /**
271  * scsi_remove_single_device - Respond to user request to remove a device
272  * @host: user-supplied decimal integer
273  * @channel: user-supplied decimal integer
274  * @id: user-supplied decimal integer
275  * @lun: user-supplied decimal integer
276  *
277  * Description: called by writing "scsi remove-single-device" to
278  * /proc/scsi/scsi.  Does a scsi_device_lookup() and scsi_remove_device()
279  */
280 static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
281 {
282 	struct scsi_device *sdev;
283 	struct Scsi_Host *shost;
284 	int error = -ENXIO;
285 
286 	shost = scsi_host_lookup(host);
287 	if (!shost)
288 		return error;
289 	sdev = scsi_device_lookup(shost, channel, id, lun);
290 	if (sdev) {
291 		scsi_remove_device(sdev);
292 		scsi_device_put(sdev);
293 		error = 0;
294 	}
295 
296 	scsi_host_put(shost);
297 	return error;
298 }
299 
300 /**
301  * proc_scsi_write - handle writes to /proc/scsi/scsi
302  * @file: not used
303  * @buf: buffer to write
304  * @length: length of buf, at most PAGE_SIZE
305  * @ppos: not used
306  *
307  * Description: this provides a legacy mechanism to add or remove devices by
308  * Host, Channel, ID, and Lun.  To use,
309  * "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
310  * "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
311  * "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
312  *
313  * Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
314  * SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
315  * provide a unique identifier and nothing more.
316  */
317 
318 
319 static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
320 			       size_t length, loff_t *ppos)
321 {
322 	int host, channel, id, lun;
323 	char *buffer, *p;
324 	int err;
325 
326 	if (!buf || length > PAGE_SIZE)
327 		return -EINVAL;
328 
329 	buffer = (char *)__get_free_page(GFP_KERNEL);
330 	if (!buffer)
331 		return -ENOMEM;
332 
333 	err = -EFAULT;
334 	if (copy_from_user(buffer, buf, length))
335 		goto out;
336 
337 	err = -EINVAL;
338 	if (length < PAGE_SIZE)
339 		buffer[length] = '\0';
340 	else if (buffer[PAGE_SIZE-1])
341 		goto out;
342 
343 	/*
344 	 * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
345 	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
346 	 */
347 	if (!strncmp("scsi add-single-device", buffer, 22)) {
348 		p = buffer + 23;
349 
350 		host = simple_strtoul(p, &p, 0);
351 		channel = simple_strtoul(p + 1, &p, 0);
352 		id = simple_strtoul(p + 1, &p, 0);
353 		lun = simple_strtoul(p + 1, &p, 0);
354 
355 		err = scsi_add_single_device(host, channel, id, lun);
356 
357 	/*
358 	 * Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
359 	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
360 	 */
361 	} else if (!strncmp("scsi remove-single-device", buffer, 25)) {
362 		p = buffer + 26;
363 
364 		host = simple_strtoul(p, &p, 0);
365 		channel = simple_strtoul(p + 1, &p, 0);
366 		id = simple_strtoul(p + 1, &p, 0);
367 		lun = simple_strtoul(p + 1, &p, 0);
368 
369 		err = scsi_remove_single_device(host, channel, id, lun);
370 	}
371 
372 	/*
373 	 * convert success returns so that we return the
374 	 * number of bytes consumed.
375 	 */
376 	if (!err)
377 		err = length;
378 
379  out:
380 	free_page((unsigned long)buffer);
381 	return err;
382 }
383 
384 static int always_match(struct device *dev, void *data)
385 {
386 	return 1;
387 }
388 
389 static inline struct device *next_scsi_device(struct device *start)
390 {
391 	struct device *next = bus_find_device(&scsi_bus_type, start, NULL,
392 					      always_match);
393 	put_device(start);
394 	return next;
395 }
396 
397 static void *scsi_seq_start(struct seq_file *sfile, loff_t *pos)
398 {
399 	struct device *dev = NULL;
400 	loff_t n = *pos;
401 
402 	while ((dev = next_scsi_device(dev))) {
403 		if (!n--)
404 			break;
405 		sfile->private++;
406 	}
407 	return dev;
408 }
409 
410 static void *scsi_seq_next(struct seq_file *sfile, void *v, loff_t *pos)
411 {
412 	(*pos)++;
413 	sfile->private++;
414 	return next_scsi_device(v);
415 }
416 
417 static void scsi_seq_stop(struct seq_file *sfile, void *v)
418 {
419 	put_device(v);
420 }
421 
422 static int scsi_seq_show(struct seq_file *sfile, void *dev)
423 {
424 	if (!sfile->private)
425 		seq_puts(sfile, "Attached devices:\n");
426 
427 	return proc_print_scsidevice(dev, sfile);
428 }
429 
430 static const struct seq_operations scsi_seq_ops = {
431 	.start	= scsi_seq_start,
432 	.next	= scsi_seq_next,
433 	.stop	= scsi_seq_stop,
434 	.show	= scsi_seq_show
435 };
436 
437 /**
438  * proc_scsi_open - glue function
439  * @inode: not used
440  * @file: passed to single_open()
441  *
442  * Associates proc_scsi_show with this file
443  */
444 static int proc_scsi_open(struct inode *inode, struct file *file)
445 {
446 	/*
447 	 * We don't really need this for the write case but it doesn't
448 	 * harm either.
449 	 */
450 	return seq_open(file, &scsi_seq_ops);
451 }
452 
453 static const struct file_operations proc_scsi_operations = {
454 	.owner		= THIS_MODULE,
455 	.open		= proc_scsi_open,
456 	.read		= seq_read,
457 	.write		= proc_scsi_write,
458 	.llseek		= seq_lseek,
459 	.release	= seq_release,
460 };
461 
462 /**
463  * scsi_init_procfs - create scsi and scsi/scsi in procfs
464  */
465 int __init scsi_init_procfs(void)
466 {
467 	struct proc_dir_entry *pde;
468 
469 	proc_scsi = proc_mkdir("scsi", NULL);
470 	if (!proc_scsi)
471 		goto err1;
472 
473 	pde = proc_create("scsi/scsi", 0, NULL, &proc_scsi_operations);
474 	if (!pde)
475 		goto err2;
476 
477 	return 0;
478 
479 err2:
480 	remove_proc_entry("scsi", NULL);
481 err1:
482 	return -ENOMEM;
483 }
484 
485 /**
486  * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
487  */
488 void scsi_exit_procfs(void)
489 {
490 	remove_proc_entry("scsi/scsi", NULL);
491 	remove_proc_entry("scsi", NULL);
492 }
493