xref: /linux/drivers/s390/char/tape_proc.c (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *    tape device driver for S/390 and zSeries tapes.
4  *
5  *  S390 and zSeries version
6  *    Copyright IBM Corp. 2001
7  *    Author(s): Carsten Otte <cotte@de.ibm.com>
8  *		 Michael Holzheu <holzheu@de.ibm.com>
9  *		 Tuan Ngo-Anh <ngoanh@de.ibm.com>
10  *
11  * PROCFS Functions
12  */
13 
14 #define pr_fmt(fmt) "tape: " fmt
15 
16 #include <linux/module.h>
17 #include <linux/vmalloc.h>
18 #include <linux/seq_file.h>
19 #include <linux/proc_fs.h>
20 
21 #define TAPE_DBF_AREA	tape_core_dbf
22 
23 #include "tape.h"
24 
25 static const char *tape_med_st_verbose[MS_SIZE] =
26 {
27 	[MS_UNKNOWN] = "UNKNOWN ",
28 	[MS_LOADED] = "LOADED  ",
29 	[MS_UNLOADED] = "UNLOADED"
30 };
31 
32 /* our proc tapedevices entry */
33 static struct proc_dir_entry *tape_proc_devices;
34 
35 /*
36  * Show function for /proc/tapedevices
37  */
38 static int tape_proc_show(struct seq_file *m, void *v)
39 {
40 	struct tape_device *device;
41 	struct tape_request *request;
42 	const char *str;
43 	unsigned long n;
44 
45 	n = (unsigned long) v - 1;
46 	if (!n) {
47 		seq_printf(m, "TapeNo\tBusID      CuType/Model\t"
48 			"DevType/Model\tBlkSize\tState\tOp\tMedState\n");
49 	}
50 	device = tape_find_device(n);
51 	if (IS_ERR(device))
52 		return 0;
53 	spin_lock_irq(get_ccwdev_lock(device->cdev));
54 	seq_printf(m, "%d\t", (int) n);
55 	seq_printf(m, "%-10.10s ", dev_name(&device->cdev->dev));
56 	seq_printf(m, "%04X/", device->cdev->id.cu_type);
57 	seq_printf(m, "%02X\t", device->cdev->id.cu_model);
58 	seq_printf(m, "%04X/", device->cdev->id.dev_type);
59 	seq_printf(m, "%02X\t\t", device->cdev->id.dev_model);
60 	if (device->char_data.block_size == 0)
61 		seq_printf(m, "auto\t");
62 	else
63 		seq_printf(m, "%i\t", device->char_data.block_size);
64 	if (device->tape_state >= 0 &&
65 	    device->tape_state < TS_SIZE)
66 		str = tape_state_verbose[device->tape_state];
67 	else
68 		str = "UNKNOWN";
69 	seq_printf(m, "%s\t", str);
70 	if (!list_empty(&device->req_queue)) {
71 		request = list_entry(device->req_queue.next,
72 				     struct tape_request, list);
73 		str = tape_op_verbose[request->op];
74 	} else
75 		str = "---";
76 	seq_printf(m, "%s\t", str);
77 	seq_printf(m, "%s\n", tape_med_st_verbose[device->medium_state]);
78 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
79 	tape_put_device(device);
80         return 0;
81 }
82 
83 static void *tape_proc_start(struct seq_file *m, loff_t *pos)
84 {
85 	if (*pos >= 256 / TAPE_MINORS_PER_DEV)
86 		return NULL;
87 	return (void *)((unsigned long) *pos + 1);
88 }
89 
90 static void *tape_proc_next(struct seq_file *m, void *v, loff_t *pos)
91 {
92 	++*pos;
93 	return tape_proc_start(m, pos);
94 }
95 
96 static void tape_proc_stop(struct seq_file *m, void *v)
97 {
98 }
99 
100 static const struct seq_operations tape_proc_seq = {
101 	.start		= tape_proc_start,
102 	.next		= tape_proc_next,
103 	.stop		= tape_proc_stop,
104 	.show		= tape_proc_show,
105 };
106 
107 /*
108  * Initialize procfs stuff on startup
109  */
110 void
111 tape_proc_init(void)
112 {
113 	tape_proc_devices = proc_create_seq("tapedevices", 0444, NULL,
114 					    &tape_proc_seq);
115 }
116 
117 /*
118  * Cleanup all stuff registered to the procfs
119  */
120 void
121 tape_proc_cleanup(void)
122 {
123 	if (tape_proc_devices != NULL)
124 		remove_proc_entry ("tapedevices", NULL);
125 }
126