xref: /openbmc/linux/drivers/s390/char/tape_proc.c (revision 87ccdcfa)
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 KMSG_COMPONENT "tape"
15 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
16 
17 #include <linux/module.h>
18 #include <linux/vmalloc.h>
19 #include <linux/seq_file.h>
20 #include <linux/proc_fs.h>
21 
22 #define TAPE_DBF_AREA	tape_core_dbf
23 
24 #include "tape.h"
25 
26 static const char *tape_med_st_verbose[MS_SIZE] =
27 {
28 	[MS_UNKNOWN] = "UNKNOWN ",
29 	[MS_LOADED] = "LOADED  ",
30 	[MS_UNLOADED] = "UNLOADED"
31 };
32 
33 /* our proc tapedevices entry */
34 static struct proc_dir_entry *tape_proc_devices;
35 
36 /*
37  * Show function for /proc/tapedevices
38  */
tape_proc_show(struct seq_file * m,void * v)39 static int tape_proc_show(struct seq_file *m, void *v)
40 {
41 	struct tape_device *device;
42 	struct tape_request *request;
43 	const char *str;
44 	unsigned long n;
45 
46 	n = (unsigned long) v - 1;
47 	if (!n) {
48 		seq_printf(m, "TapeNo\tBusID      CuType/Model\t"
49 			"DevType/Model\tBlkSize\tState\tOp\tMedState\n");
50 	}
51 	device = tape_find_device(n);
52 	if (IS_ERR(device))
53 		return 0;
54 	spin_lock_irq(get_ccwdev_lock(device->cdev));
55 	seq_printf(m, "%d\t", (int) n);
56 	seq_printf(m, "%-10.10s ", dev_name(&device->cdev->dev));
57 	seq_printf(m, "%04X/", device->cdev->id.cu_type);
58 	seq_printf(m, "%02X\t", device->cdev->id.cu_model);
59 	seq_printf(m, "%04X/", device->cdev->id.dev_type);
60 	seq_printf(m, "%02X\t\t", device->cdev->id.dev_model);
61 	if (device->char_data.block_size == 0)
62 		seq_printf(m, "auto\t");
63 	else
64 		seq_printf(m, "%i\t", device->char_data.block_size);
65 	if (device->tape_state >= 0 &&
66 	    device->tape_state < TS_SIZE)
67 		str = tape_state_verbose[device->tape_state];
68 	else
69 		str = "UNKNOWN";
70 	seq_printf(m, "%s\t", str);
71 	if (!list_empty(&device->req_queue)) {
72 		request = list_entry(device->req_queue.next,
73 				     struct tape_request, list);
74 		str = tape_op_verbose[request->op];
75 	} else
76 		str = "---";
77 	seq_printf(m, "%s\t", str);
78 	seq_printf(m, "%s\n", tape_med_st_verbose[device->medium_state]);
79 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
80 	tape_put_device(device);
81         return 0;
82 }
83 
tape_proc_start(struct seq_file * m,loff_t * pos)84 static void *tape_proc_start(struct seq_file *m, loff_t *pos)
85 {
86 	if (*pos >= 256 / TAPE_MINORS_PER_DEV)
87 		return NULL;
88 	return (void *)((unsigned long) *pos + 1);
89 }
90 
tape_proc_next(struct seq_file * m,void * v,loff_t * pos)91 static void *tape_proc_next(struct seq_file *m, void *v, loff_t *pos)
92 {
93 	++*pos;
94 	return tape_proc_start(m, pos);
95 }
96 
tape_proc_stop(struct seq_file * m,void * v)97 static void tape_proc_stop(struct seq_file *m, void *v)
98 {
99 }
100 
101 static const struct seq_operations tape_proc_seq = {
102 	.start		= tape_proc_start,
103 	.next		= tape_proc_next,
104 	.stop		= tape_proc_stop,
105 	.show		= tape_proc_show,
106 };
107 
108 /*
109  * Initialize procfs stuff on startup
110  */
111 void
tape_proc_init(void)112 tape_proc_init(void)
113 {
114 	tape_proc_devices = proc_create_seq("tapedevices", 0444, NULL,
115 					    &tape_proc_seq);
116 }
117 
118 /*
119  * Cleanup all stuff registered to the procfs
120  */
121 void
tape_proc_cleanup(void)122 tape_proc_cleanup(void)
123 {
124 	if (tape_proc_devices != NULL)
125 		remove_proc_entry ("tapedevices", NULL);
126 }
127