tape_proc.c

  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
 25static 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 */
 33static struct proc_dir_entry *tape_proc_devices;
 34
 35/*
 36 * Show function for /proc/tapedevices
 37 */
 38static 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
 83static 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
 90static 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
 96static void tape_proc_stop(struct seq_file *m, void *v)
 97{
 98}
 99
100static 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 */
110void
111tape_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 */
120void
121tape_proc_cleanup(void)
122{
123	if (tape_proc_devices != NULL)
124		remove_proc_entry ("tapedevices", NULL);
125}