tape_proc.c

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/*
 *    tape device driver for S/390 and zSeries tapes.
 *
 *  S390 and zSeries version
 *    Copyright IBM Corp. 2001
 *    Author(s): Carsten Otte <[email protected]>
 *       Michael Holzheu <[email protected]>
 *       Tuan Ngo-Anh <[email protected]>
 *
 * PROCFS Functions
 */

#define KMSG_COMPONENT "tape"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>

#define TAPE_DBF_AREA   tape_core_dbf

#include "tape.h"

static const char *tape_med_st_verbose[MS_SIZE] =
{
    [MS_UNKNOWN] = "UNKNOWN ",
    [MS_LOADED] = "LOADED  ",
    [MS_UNLOADED] = "UNLOADED"
};

/* our proc tapedevices entry */
static struct proc_dir_entry *tape_proc_devices;

/*
 * Show function for /proc/tapedevices
 */
static int tape_proc_show(struct seq_file *m, void *v)
{
    struct tape_device *device;
    struct tape_request *request;
    const char *str;
    unsigned long n;

    n = (unsigned long) v - 1;
    if (!n) {
        seq_printf(m, "TapeNo\tBusID      CuType/Model\t"
            "DevType/Model\tBlkSize\tState\tOp\tMedState\n");
    }
    device = tape_find_device(n);
    if (IS_ERR(device))
        return 0;
    spin_lock_irq(get_ccwdev_lock(device->cdev));
    seq_printf(m, "%d\t", (int) n);
    seq_printf(m, "%-10.10s ", dev_name(&device->cdev->dev));
    seq_printf(m, "%04X/", device->cdev->id.cu_type);
    seq_printf(m, "%02X\t", device->cdev->id.cu_model);
    seq_printf(m, "%04X/", device->cdev->id.dev_type);
    seq_printf(m, "%02X\t\t", device->cdev->id.dev_model);
    if (device->char_data.block_size == 0)
        seq_printf(m, "auto\t");
    else
        seq_printf(m, "%i\t", device->char_data.block_size);
    if (device->tape_state >= 0 &&
        device->tape_state < TS_SIZE)
        str = tape_state_verbose[device->tape_state];
    else
        str = "UNKNOWN";
    seq_printf(m, "%s\t", str);
    if (!list_empty(&device->req_queue)) {
        request = list_entry(device->req_queue.next,
                     struct tape_request, list);
        str = tape_op_verbose[request->op];
    } else
        str = "---";
    seq_printf(m, "%s\t", str);
    seq_printf(m, "%s\n", tape_med_st_verbose[device->medium_state]);
    spin_unlock_irq(get_ccwdev_lock(device->cdev));
    tape_put_device(device);
        return 0;
}

static void *tape_proc_start(struct seq_file *m, loff_t *pos)
{
    if (*pos >= 256 / TAPE_MINORS_PER_DEV)
        return NULL;
    return (void *)((unsigned long) *pos + 1);
}

static void *tape_proc_next(struct seq_file *m, void *v, loff_t *pos)
{
    ++*pos;
    return tape_proc_start(m, pos);
}

static void tape_proc_stop(struct seq_file *m, void *v)
{
}

static const struct seq_operations tape_proc_seq = {
    .start      = tape_proc_start,
    .next       = tape_proc_next,
    .stop       = tape_proc_stop,
    .show       = tape_proc_show,
};

static int tape_proc_open(struct inode *inode, struct file *file)
{
    return seq_open(file, &tape_proc_seq);
}

static const struct file_operations tape_proc_ops =
{
    .owner      = THIS_MODULE,
    .open       = tape_proc_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = seq_release,
};

/*
 * Initialize procfs stuff on startup
 */
void
tape_proc_init(void)
{
    tape_proc_devices =
        proc_create("tapedevices", S_IFREG | S_IRUGO | S_IWUSR, NULL,
                &tape_proc_ops);
    if (tape_proc_devices == NULL) {
        return;
    }
}

/*
 * Cleanup all stuff registered to the procfs
 */
void
tape_proc_cleanup(void)
{
    if (tape_proc_devices != NULL)
        remove_proc_entry ("tapedevices", NULL);
}