2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-24 21:24:00 +08:00
linux-next/drivers/s390/char/monwriter.c
Arjan van de Ven d54b1fdb1d [PATCH] mark struct file_operations const 5
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>
2007-02-12 09:48:45 -08:00

299 lines
7.1 KiB
C

/*
* drivers/s390/char/monwriter.c
*
* Character device driver for writing z/VM *MONITOR service records.
*
* Copyright (C) IBM Corp. 2006
*
* Author(s): Melissa Howland <Melissa.Howland@us.ibm.com>
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/ctype.h>
#include <linux/poll.h>
#include <asm/uaccess.h>
#include <asm/ebcdic.h>
#include <asm/io.h>
#include <asm/appldata.h>
#include <asm/monwriter.h>
#define MONWRITE_MAX_DATALEN 4010
static int mon_max_bufs = 255;
static int mon_buf_count;
struct mon_buf {
struct list_head list;
struct monwrite_hdr hdr;
int diag_done;
char *data;
};
struct mon_private {
struct list_head list;
struct monwrite_hdr hdr;
size_t hdr_to_read;
size_t data_to_read;
struct mon_buf *current_buf;
};
/*
* helper functions
*/
static int monwrite_diag(struct monwrite_hdr *myhdr, char *buffer, int fcn)
{
struct appldata_product_id id;
int rc;
strcpy(id.prod_nr, "LNXAPPL");
id.prod_fn = myhdr->applid;
id.record_nr = myhdr->record_num;
id.version_nr = myhdr->version;
id.release_nr = myhdr->release;
id.mod_lvl = myhdr->mod_level;
rc = appldata_asm(&id, fcn, (void *) buffer, myhdr->datalen);
if (rc <= 0)
return rc;
if (rc == 5)
return -EPERM;
printk("DIAG X'DC' error with return code: %i\n", rc);
return -EINVAL;
}
static struct mon_buf *monwrite_find_hdr(struct mon_private *monpriv,
struct monwrite_hdr *monhdr)
{
struct mon_buf *entry, *next;
list_for_each_entry_safe(entry, next, &monpriv->list, list)
if ((entry->hdr.mon_function == monhdr->mon_function ||
monhdr->mon_function == MONWRITE_STOP_INTERVAL) &&
entry->hdr.applid == monhdr->applid &&
entry->hdr.record_num == monhdr->record_num &&
entry->hdr.version == monhdr->version &&
entry->hdr.release == monhdr->release &&
entry->hdr.mod_level == monhdr->mod_level)
return entry;
return NULL;
}
static int monwrite_new_hdr(struct mon_private *monpriv)
{
struct monwrite_hdr *monhdr = &monpriv->hdr;
struct mon_buf *monbuf;
int rc;
if (monhdr->datalen > MONWRITE_MAX_DATALEN ||
monhdr->mon_function > MONWRITE_START_CONFIG ||
monhdr->hdrlen != sizeof(struct monwrite_hdr))
return -EINVAL;
monbuf = NULL;
if (monhdr->mon_function != MONWRITE_GEN_EVENT)
monbuf = monwrite_find_hdr(monpriv, monhdr);
if (monbuf) {
if (monhdr->mon_function == MONWRITE_STOP_INTERVAL) {
monhdr->datalen = monbuf->hdr.datalen;
rc = monwrite_diag(monhdr, monbuf->data,
APPLDATA_STOP_REC);
list_del(&monbuf->list);
mon_buf_count--;
kfree(monbuf->data);
kfree(monbuf);
monbuf = NULL;
}
} else if (monhdr->mon_function != MONWRITE_STOP_INTERVAL) {
if (mon_buf_count >= mon_max_bufs)
return -ENOSPC;
monbuf = kzalloc(sizeof(struct mon_buf), GFP_KERNEL);
if (!monbuf)
return -ENOMEM;
monbuf->data = kzalloc(monhdr->datalen,
GFP_KERNEL | GFP_DMA);
if (!monbuf->data) {
kfree(monbuf);
return -ENOMEM;
}
monbuf->hdr = *monhdr;
list_add_tail(&monbuf->list, &monpriv->list);
if (monhdr->mon_function != MONWRITE_GEN_EVENT)
mon_buf_count++;
}
monpriv->current_buf = monbuf;
return 0;
}
static int monwrite_new_data(struct mon_private *monpriv)
{
struct monwrite_hdr *monhdr = &monpriv->hdr;
struct mon_buf *monbuf = monpriv->current_buf;
int rc = 0;
switch (monhdr->mon_function) {
case MONWRITE_START_INTERVAL:
if (!monbuf->diag_done) {
rc = monwrite_diag(monhdr, monbuf->data,
APPLDATA_START_INTERVAL_REC);
monbuf->diag_done = 1;
}
break;
case MONWRITE_START_CONFIG:
if (!monbuf->diag_done) {
rc = monwrite_diag(monhdr, monbuf->data,
APPLDATA_START_CONFIG_REC);
monbuf->diag_done = 1;
}
break;
case MONWRITE_GEN_EVENT:
rc = monwrite_diag(monhdr, monbuf->data,
APPLDATA_GEN_EVENT_REC);
list_del(&monpriv->current_buf->list);
kfree(monpriv->current_buf->data);
kfree(monpriv->current_buf);
monpriv->current_buf = NULL;
break;
default:
/* monhdr->mon_function is checked in monwrite_new_hdr */
BUG();
}
return rc;
}
/*
* file operations
*/
static int monwrite_open(struct inode *inode, struct file *filp)
{
struct mon_private *monpriv;
monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
if (!monpriv)
return -ENOMEM;
INIT_LIST_HEAD(&monpriv->list);
monpriv->hdr_to_read = sizeof(monpriv->hdr);
filp->private_data = monpriv;
return nonseekable_open(inode, filp);
}
static int monwrite_close(struct inode *inode, struct file *filp)
{
struct mon_private *monpriv = filp->private_data;
struct mon_buf *entry, *next;
list_for_each_entry_safe(entry, next, &monpriv->list, list) {
if (entry->hdr.mon_function != MONWRITE_GEN_EVENT)
monwrite_diag(&entry->hdr, entry->data,
APPLDATA_STOP_REC);
mon_buf_count--;
list_del(&entry->list);
kfree(entry->data);
kfree(entry);
}
kfree(monpriv);
return 0;
}
static ssize_t monwrite_write(struct file *filp, const char __user *data,
size_t count, loff_t *ppos)
{
struct mon_private *monpriv = filp->private_data;
size_t len, written;
void *to;
int rc;
for (written = 0; written < count; ) {
if (monpriv->hdr_to_read) {
len = min(count - written, monpriv->hdr_to_read);
to = (char *) &monpriv->hdr +
sizeof(monpriv->hdr) - monpriv->hdr_to_read;
if (copy_from_user(to, data + written, len)) {
rc = -EFAULT;
goto out_error;
}
monpriv->hdr_to_read -= len;
written += len;
if (monpriv->hdr_to_read > 0)
continue;
rc = monwrite_new_hdr(monpriv);
if (rc)
goto out_error;
monpriv->data_to_read = monpriv->current_buf ?
monpriv->current_buf->hdr.datalen : 0;
}
if (monpriv->data_to_read) {
len = min(count - written, monpriv->data_to_read);
to = monpriv->current_buf->data +
monpriv->hdr.datalen - monpriv->data_to_read;
if (copy_from_user(to, data + written, len)) {
rc = -EFAULT;
goto out_error;
}
monpriv->data_to_read -= len;
written += len;
if (monpriv->data_to_read > 0)
continue;
rc = monwrite_new_data(monpriv);
if (rc)
goto out_error;
}
monpriv->hdr_to_read = sizeof(monpriv->hdr);
}
return written;
out_error:
monpriv->data_to_read = 0;
monpriv->hdr_to_read = sizeof(struct monwrite_hdr);
return rc;
}
static const struct file_operations monwrite_fops = {
.owner = THIS_MODULE,
.open = &monwrite_open,
.release = &monwrite_close,
.write = &monwrite_write,
};
static struct miscdevice mon_dev = {
.name = "monwriter",
.fops = &monwrite_fops,
.minor = MISC_DYNAMIC_MINOR,
};
/*
* module init/exit
*/
static int __init mon_init(void)
{
if (MACHINE_IS_VM)
return misc_register(&mon_dev);
else
return -ENODEV;
}
static void __exit mon_exit(void)
{
WARN_ON(misc_deregister(&mon_dev) != 0);
}
module_init(mon_init);
module_exit(mon_exit);
module_param_named(max_bufs, mon_max_bufs, int, 0644);
MODULE_PARM_DESC(max_bufs, "Maximum number of sample monitor data buffers"
"that can be active at one time");
MODULE_AUTHOR("Melissa Howland <Melissa.Howland@us.ibm.com>");
MODULE_DESCRIPTION("Character device driver for writing z/VM "
"APPLDATA monitor records.");
MODULE_LICENSE("GPL");