drivers/s390/char/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 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  */
  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
  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
  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
  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
 112 tape_proc_init(void)
 113 {
 114         tape_proc_devices = proc_create_seq("tapedevices",
 115                         S_IFREG | S_IRUGO | S_IWUSR, NULL,  &tape_proc_seq);
 116         if (tape_proc_devices == NULL) {
 117                 return;
 118         }
 119 }
 120
 121 /*
 122  * Cleanup all stuff registered to the procfs
 123  */
 124 void
 125 tape_proc_cleanup(void)
 126 {
 127         if (tape_proc_devices != NULL)
 128                 remove_proc_entry ("tapedevices", NULL);
 129 }