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d54b1fdb1d
Many struct file_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
146 lines
3.4 KiB
C
146 lines
3.4 KiB
C
/*
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* drivers/s390/char/tape.c
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* tape device driver for S/390 and zSeries tapes.
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*
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* S390 and zSeries version
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* Copyright (C) 2001 IBM Corporation
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* Author(s): Carsten Otte <cotte@de.ibm.com>
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* Michael Holzheu <holzheu@de.ibm.com>
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* Tuan Ngo-Anh <ngoanh@de.ibm.com>
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*
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* PROCFS Functions
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*/
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#include <linux/module.h>
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#include <linux/vmalloc.h>
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#include <linux/seq_file.h>
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#include <linux/proc_fs.h>
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#define TAPE_DBF_AREA tape_core_dbf
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#include "tape.h"
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#define PRINTK_HEADER "TAPE_PROC: "
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static const char *tape_med_st_verbose[MS_SIZE] =
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{
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[MS_UNKNOWN] = "UNKNOWN ",
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[MS_LOADED] = "LOADED ",
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[MS_UNLOADED] = "UNLOADED"
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};
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/* our proc tapedevices entry */
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static struct proc_dir_entry *tape_proc_devices;
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/*
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* Show function for /proc/tapedevices
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*/
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static int tape_proc_show(struct seq_file *m, void *v)
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{
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struct tape_device *device;
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struct tape_request *request;
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const char *str;
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unsigned long n;
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n = (unsigned long) v - 1;
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if (!n) {
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seq_printf(m, "TapeNo\tBusID CuType/Model\t"
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"DevType/Model\tBlkSize\tState\tOp\tMedState\n");
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}
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device = tape_get_device(n);
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if (IS_ERR(device))
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return 0;
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spin_lock_irq(get_ccwdev_lock(device->cdev));
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seq_printf(m, "%d\t", (int) n);
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seq_printf(m, "%-10.10s ", device->cdev->dev.bus_id);
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seq_printf(m, "%04X/", device->cdev->id.cu_type);
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seq_printf(m, "%02X\t", device->cdev->id.cu_model);
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seq_printf(m, "%04X/", device->cdev->id.dev_type);
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seq_printf(m, "%02X\t\t", device->cdev->id.dev_model);
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if (device->char_data.block_size == 0)
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seq_printf(m, "auto\t");
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else
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seq_printf(m, "%i\t", device->char_data.block_size);
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if (device->tape_state >= 0 &&
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device->tape_state < TS_SIZE)
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str = tape_state_verbose[device->tape_state];
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else
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str = "UNKNOWN";
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seq_printf(m, "%s\t", str);
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if (!list_empty(&device->req_queue)) {
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request = list_entry(device->req_queue.next,
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struct tape_request, list);
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str = tape_op_verbose[request->op];
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} else
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str = "---";
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seq_printf(m, "%s\t", str);
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seq_printf(m, "%s\n", tape_med_st_verbose[device->medium_state]);
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spin_unlock_irq(get_ccwdev_lock(device->cdev));
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tape_put_device(device);
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return 0;
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}
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static void *tape_proc_start(struct seq_file *m, loff_t *pos)
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{
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if (*pos >= 256 / TAPE_MINORS_PER_DEV)
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return NULL;
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return (void *)((unsigned long) *pos + 1);
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}
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static void *tape_proc_next(struct seq_file *m, void *v, loff_t *pos)
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{
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++*pos;
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return tape_proc_start(m, pos);
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}
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static void tape_proc_stop(struct seq_file *m, void *v)
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{
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}
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static struct seq_operations tape_proc_seq = {
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.start = tape_proc_start,
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.next = tape_proc_next,
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.stop = tape_proc_stop,
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.show = tape_proc_show,
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};
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static int tape_proc_open(struct inode *inode, struct file *file)
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{
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return seq_open(file, &tape_proc_seq);
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}
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static const struct file_operations tape_proc_ops =
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{
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.open = tape_proc_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release,
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};
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/*
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* Initialize procfs stuff on startup
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*/
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void
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tape_proc_init(void)
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{
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tape_proc_devices =
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create_proc_entry ("tapedevices", S_IFREG | S_IRUGO | S_IWUSR,
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&proc_root);
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if (tape_proc_devices == NULL) {
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PRINT_WARN("tape: Cannot register procfs entry tapedevices\n");
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return;
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}
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tape_proc_devices->proc_fops = &tape_proc_ops;
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tape_proc_devices->owner = THIS_MODULE;
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}
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/*
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* Cleanup all stuff registered to the procfs
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*/
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void
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tape_proc_cleanup(void)
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{
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if (tape_proc_devices != NULL)
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remove_proc_entry ("tapedevices", &proc_root);
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}
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