1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4 *		    Horst Hummel <Horst.Hummel@de.ibm.com>
5 *		    Carsten Otte <Cotte@de.ibm.com>
6 *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
7 * Bugreports.to..: <Linux390@de.ibm.com>
8 * Copyright IBM Corp. 1999, 2002
9 *
10 * /proc interface for the dasd driver.
11 *
12 */
13
14#define KMSG_COMPONENT "dasd"
15
16#include <linux/ctype.h>
17#include <linux/slab.h>
18#include <linux/string.h>
19#include <linux/seq_file.h>
20#include <linux/vmalloc.h>
21#include <linux/proc_fs.h>
22
23#include <asm/debug.h>
24#include <linux/uaccess.h>
25
26/* This is ugly... */
27#define PRINTK_HEADER "dasd_proc:"
28
29#include "dasd_int.h"
30
31static struct proc_dir_entry *dasd_proc_root_entry = NULL;
32static struct proc_dir_entry *dasd_devices_entry = NULL;
33static struct proc_dir_entry *dasd_statistics_entry = NULL;
34
35static int
36dasd_devices_show(struct seq_file *m, void *v)
37{
38	struct dasd_device *device;
39	struct dasd_block *block;
40	char *substr;
41
42	device = dasd_device_from_devindex((unsigned long) v - 1);
43	if (IS_ERR(device))
44		return 0;
45	if (device->block)
46		block = device->block;
47	else {
48		dasd_put_device(device);
49		return 0;
50	}
51	/* Print device number. */
52	seq_printf(m, "%s", dev_name(&device->cdev->dev));
53	/* Print discipline string. */
54	if (device->discipline != NULL)
55		seq_printf(m, "(%s)", device->discipline->name);
56	else
57		seq_printf(m, "(none)");
58	/* Print kdev. */
59	if (block->gdp)
60		seq_printf(m, " at (%3d:%6d)",
61			   MAJOR(disk_devt(block->gdp)),
62			   MINOR(disk_devt(block->gdp)));
63	else
64		seq_printf(m, "  at (???:??????)");
65	/* Print device name. */
66	if (block->gdp)
67		seq_printf(m, " is %-8s", block->gdp->disk_name);
68	else
69		seq_printf(m, " is ????????");
70	/* Print devices features. */
71	substr = (device->features & DASD_FEATURE_READONLY) ? "(ro)" : " ";
72	seq_printf(m, "%4s: ", substr);
73	/* Print device status information. */
74	switch (device->state) {
75	case DASD_STATE_NEW:
76		seq_printf(m, "new");
77		break;
78	case DASD_STATE_KNOWN:
79		seq_printf(m, "detected");
80		break;
81	case DASD_STATE_BASIC:
82		seq_printf(m, "basic");
83		break;
84	case DASD_STATE_UNFMT:
85		seq_printf(m, "unformatted");
86		break;
87	case DASD_STATE_READY:
88	case DASD_STATE_ONLINE:
89		seq_printf(m, "active ");
90		if (dasd_check_blocksize(block->bp_block))
91			seq_printf(m, "n/f	 ");
92		else
93			seq_printf(m,
94				   "at blocksize: %u, %lu blocks, %lu MB",
95				   block->bp_block, block->blocks,
96				   ((block->bp_block >> 9) *
97				    block->blocks) >> 11);
98		break;
99	default:
100		seq_printf(m, "no stat");
101		break;
102	}
103	dasd_put_device(device);
104	if (dasd_probeonly)
105		seq_printf(m, "(probeonly)");
106	seq_printf(m, "\n");
107	return 0;
108}
109
110static void *dasd_devices_start(struct seq_file *m, loff_t *pos)
111{
112	if (*pos >= dasd_max_devindex)
113		return NULL;
114	return (void *)((unsigned long) *pos + 1);
115}
116
117static void *dasd_devices_next(struct seq_file *m, void *v, loff_t *pos)
118{
119	++*pos;
120	return dasd_devices_start(m, pos);
121}
122
123static void dasd_devices_stop(struct seq_file *m, void *v)
124{
125}
126
127static const struct seq_operations dasd_devices_seq_ops = {
128	.start		= dasd_devices_start,
129	.next		= dasd_devices_next,
130	.stop		= dasd_devices_stop,
131	.show		= dasd_devices_show,
132};
133
134#ifdef CONFIG_DASD_PROFILE
135static int dasd_stats_all_block_on(void)
136{
137	int i, rc;
138	struct dasd_device *device;
139
140	rc = 0;
141	for (i = 0; i < dasd_max_devindex; ++i) {
142		device = dasd_device_from_devindex(i);
143		if (IS_ERR(device))
144			continue;
145		if (device->block)
146			rc = dasd_profile_on(&device->block->profile);
147		dasd_put_device(device);
148		if (rc)
149			return rc;
150	}
151	return 0;
152}
153
154static void dasd_stats_all_block_off(void)
155{
156	int i;
157	struct dasd_device *device;
158
159	for (i = 0; i < dasd_max_devindex; ++i) {
160		device = dasd_device_from_devindex(i);
161		if (IS_ERR(device))
162			continue;
163		if (device->block)
164			dasd_profile_off(&device->block->profile);
165		dasd_put_device(device);
166	}
167}
168
169static void dasd_stats_all_block_reset(void)
170{
171	int i;
172	struct dasd_device *device;
173
174	for (i = 0; i < dasd_max_devindex; ++i) {
175		device = dasd_device_from_devindex(i);
176		if (IS_ERR(device))
177			continue;
178		if (device->block)
179			dasd_profile_reset(&device->block->profile);
180		dasd_put_device(device);
181	}
182}
183
184static void dasd_statistics_array(struct seq_file *m, unsigned int *array, int factor)
185{
186	int i;
187
188	for (i = 0; i < 32; i++) {
189		seq_printf(m, "%7d ", array[i] / factor);
190		if (i == 15)
191			seq_putc(m, '\n');
192	}
193	seq_putc(m, '\n');
194}
195#endif /* CONFIG_DASD_PROFILE */
196
197static int dasd_stats_proc_show(struct seq_file *m, void *v)
198{
199#ifdef CONFIG_DASD_PROFILE
200	struct dasd_profile_info *prof;
201	int factor;
202
203	spin_lock_bh(&dasd_global_profile.lock);
204	prof = dasd_global_profile.data;
205	if (!prof) {
206		spin_unlock_bh(&dasd_global_profile.lock);
207		seq_printf(m, "Statistics are off - they might be "
208				    "switched on using 'echo set on > "
209				    "/proc/dasd/statistics'\n");
210		return 0;
211	}
212
213	/* prevent counter 'overflow' on output */
214	for (factor = 1; (prof->dasd_io_reqs / factor) > 9999999;
215	     factor *= 10);
216
217	seq_printf(m, "%d dasd I/O requests\n", prof->dasd_io_reqs);
218	seq_printf(m, "with %u sectors(512B each)\n",
219		       prof->dasd_io_sects);
220	seq_printf(m, "Scale Factor is  %d\n", factor);
221	seq_printf(m,
222		       "   __<4	   ___8	   __16	   __32	   __64	   _128	"
223		       "   _256	   _512	   __1k	   __2k	   __4k	   __8k	"
224		       "   _16k	   _32k	   _64k	   128k\n");
225	seq_printf(m,
226		       "   _256	   _512	   __1M	   __2M	   __4M	   __8M	"
227		       "   _16M	   _32M	   _64M	   128M	   256M	   512M	"
228		       "   __1G	   __2G	   __4G " "   _>4G\n");
229
230	seq_printf(m, "Histogram of sizes (512B secs)\n");
231	dasd_statistics_array(m, prof->dasd_io_secs, factor);
232	seq_printf(m, "Histogram of I/O times (microseconds)\n");
233	dasd_statistics_array(m, prof->dasd_io_times, factor);
234	seq_printf(m, "Histogram of I/O times per sector\n");
235	dasd_statistics_array(m, prof->dasd_io_timps, factor);
236	seq_printf(m, "Histogram of I/O time till ssch\n");
237	dasd_statistics_array(m, prof->dasd_io_time1, factor);
238	seq_printf(m, "Histogram of I/O time between ssch and irq\n");
239	dasd_statistics_array(m, prof->dasd_io_time2, factor);
240	seq_printf(m, "Histogram of I/O time between ssch "
241			    "and irq per sector\n");
242	dasd_statistics_array(m, prof->dasd_io_time2ps, factor);
243	seq_printf(m, "Histogram of I/O time between irq and end\n");
244	dasd_statistics_array(m, prof->dasd_io_time3, factor);
245	seq_printf(m, "# of req in chanq at enqueuing (1..32) \n");
246	dasd_statistics_array(m, prof->dasd_io_nr_req, factor);
247	spin_unlock_bh(&dasd_global_profile.lock);
248#else
249	seq_printf(m, "Statistics are not activated in this kernel\n");
250#endif
251	return 0;
252}
253
254static int dasd_stats_proc_open(struct inode *inode, struct file *file)
255{
256	return single_open(file, dasd_stats_proc_show, NULL);
257}
258
259static ssize_t dasd_stats_proc_write(struct file *file,
260		const char __user *user_buf, size_t user_len, loff_t *pos)
261{
262#ifdef CONFIG_DASD_PROFILE
263	char *buffer, *str;
264	int rc;
265
266	if (user_len > 65536)
267		user_len = 65536;
268	buffer = dasd_get_user_string(user_buf, user_len);
269	if (IS_ERR(buffer))
270		return PTR_ERR(buffer);
271
272	/* check for valid verbs */
273	str = skip_spaces(buffer);
274	if (strncmp(str, "set", 3) == 0 && isspace(str[3])) {
275		/* 'set xxx' was given */
276		str = skip_spaces(str + 4);
277		if (strcmp(str, "on") == 0) {
278			/* switch on statistics profiling */
279			rc = dasd_stats_all_block_on();
280			if (rc) {
281				dasd_stats_all_block_off();
282				goto out_error;
283			}
284			rc = dasd_profile_on(&dasd_global_profile);
285			if (rc) {
286				dasd_stats_all_block_off();
287				goto out_error;
288			}
289			dasd_profile_reset(&dasd_global_profile);
290			dasd_global_profile_level = DASD_PROFILE_ON;
291			pr_info("The statistics feature has been switched "
292				"on\n");
293		} else if (strcmp(str, "off") == 0) {
294			/* switch off statistics profiling */
295			dasd_global_profile_level = DASD_PROFILE_OFF;
296			dasd_profile_off(&dasd_global_profile);
297			dasd_stats_all_block_off();
298			pr_info("The statistics feature has been switched "
299				"off\n");
300		} else
301			goto out_parse_error;
302	} else if (strncmp(str, "reset", 5) == 0) {
303		/* reset the statistics */
304		dasd_profile_reset(&dasd_global_profile);
305		dasd_stats_all_block_reset();
306		pr_info("The statistics have been reset\n");
307	} else
308		goto out_parse_error;
309	vfree(buffer);
310	return user_len;
311out_parse_error:
312	rc = -EINVAL;
313	pr_warn("%s is not a supported value for /proc/dasd/statistics\n", str);
314out_error:
315	vfree(buffer);
316	return rc;
317#else
318	pr_warn("/proc/dasd/statistics: is not activated in this kernel\n");
319	return user_len;
320#endif				/* CONFIG_DASD_PROFILE */
321}
322
323static const struct proc_ops dasd_stats_proc_ops = {
324	.proc_open	= dasd_stats_proc_open,
325	.proc_read	= seq_read,
326	.proc_lseek	= seq_lseek,
327	.proc_release	= single_release,
328	.proc_write	= dasd_stats_proc_write,
329};
330
331/*
332 * Create dasd proc-fs entries.
333 * In case creation failed, cleanup and return -ENOENT.
334 */
335int
336dasd_proc_init(void)
337{
338	dasd_proc_root_entry = proc_mkdir("dasd", NULL);
339	if (!dasd_proc_root_entry)
340		goto out_nodasd;
341	dasd_devices_entry = proc_create_seq("devices", 0444,
342					 dasd_proc_root_entry,
343					 &dasd_devices_seq_ops);
344	if (!dasd_devices_entry)
345		goto out_nodevices;
346	dasd_statistics_entry = proc_create("statistics",
347					    S_IFREG | S_IRUGO | S_IWUSR,
348					    dasd_proc_root_entry,
349					    &dasd_stats_proc_ops);
350	if (!dasd_statistics_entry)
351		goto out_nostatistics;
352	return 0;
353
354 out_nostatistics:
355	remove_proc_entry("devices", dasd_proc_root_entry);
356 out_nodevices:
357	remove_proc_entry("dasd", NULL);
358 out_nodasd:
359	return -ENOENT;
360}
361
362void
363dasd_proc_exit(void)
364{
365	remove_proc_entry("devices", dasd_proc_root_entry);
366	remove_proc_entry("statistics", dasd_proc_root_entry);
367	remove_proc_entry("dasd", NULL);
368}
369