https://jxself.org/git/linux-libre.git
Tip revision: 2d81dea751272a1db9c1d8887b084bc972358283 authored by Jason Self on 09 May 2014, 06:36:02 UTC
Linux-libre 3.12.19-gnu
Linux-libre 3.12.19-gnu
Tip revision: 2d81dea
monwriter.c
/*
* Character device driver for writing z/VM *MONITOR service records.
*
* Copyright IBM Corp. 2006, 2009
*
* Author(s): Melissa Howland <Melissa.Howland@us.ibm.com>
*/
#define KMSG_COMPONENT "monwriter"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#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 <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/slab.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;
};
static LIST_HEAD(mon_priv_list);
struct mon_private {
struct list_head priv_list;
struct list_head list;
struct monwrite_hdr hdr;
size_t hdr_to_read;
size_t data_to_read;
struct mon_buf *current_buf;
struct mutex thread_mutex;
};
/*
* 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;
pr_err("Writing monitor data failed with rc=%i\n", rc);
if (rc == 5)
return -EPERM;
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 = 0;
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 rc;
}
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);
mutex_init(&monpriv->thread_mutex);
filp->private_data = monpriv;
list_add_tail(&monpriv->priv_list, &mon_priv_list);
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);
}
list_del(&monpriv->priv_list);
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;
mutex_lock(&monpriv->thread_mutex);
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);
}
mutex_unlock(&monpriv->thread_mutex);
return written;
out_error:
monpriv->data_to_read = 0;
monpriv->hdr_to_read = sizeof(struct monwrite_hdr);
mutex_unlock(&monpriv->thread_mutex);
return rc;
}
static const struct file_operations monwrite_fops = {
.owner = THIS_MODULE,
.open = &monwrite_open,
.release = &monwrite_close,
.write = &monwrite_write,
.llseek = noop_llseek,
};
static struct miscdevice mon_dev = {
.name = "monwriter",
.fops = &monwrite_fops,
.minor = MISC_DYNAMIC_MINOR,
};
/*
* suspend/resume
*/
static int monwriter_freeze(struct device *dev)
{
struct mon_private *monpriv;
struct mon_buf *monbuf;
list_for_each_entry(monpriv, &mon_priv_list, priv_list) {
list_for_each_entry(monbuf, &monpriv->list, list) {
if (monbuf->hdr.mon_function != MONWRITE_GEN_EVENT)
monwrite_diag(&monbuf->hdr, monbuf->data,
APPLDATA_STOP_REC);
}
}
return 0;
}
static int monwriter_restore(struct device *dev)
{
struct mon_private *monpriv;
struct mon_buf *monbuf;
list_for_each_entry(monpriv, &mon_priv_list, priv_list) {
list_for_each_entry(monbuf, &monpriv->list, list) {
if (monbuf->hdr.mon_function == MONWRITE_START_INTERVAL)
monwrite_diag(&monbuf->hdr, monbuf->data,
APPLDATA_START_INTERVAL_REC);
if (monbuf->hdr.mon_function == MONWRITE_START_CONFIG)
monwrite_diag(&monbuf->hdr, monbuf->data,
APPLDATA_START_CONFIG_REC);
}
}
return 0;
}
static int monwriter_thaw(struct device *dev)
{
return monwriter_restore(dev);
}
static const struct dev_pm_ops monwriter_pm_ops = {
.freeze = monwriter_freeze,
.thaw = monwriter_thaw,
.restore = monwriter_restore,
};
static struct platform_driver monwriter_pdrv = {
.driver = {
.name = "monwriter",
.owner = THIS_MODULE,
.pm = &monwriter_pm_ops,
},
};
static struct platform_device *monwriter_pdev;
/*
* module init/exit
*/
static int __init mon_init(void)
{
int rc;
if (!MACHINE_IS_VM)
return -ENODEV;
rc = platform_driver_register(&monwriter_pdrv);
if (rc)
return rc;
monwriter_pdev = platform_device_register_simple("monwriter", -1, NULL,
0);
if (IS_ERR(monwriter_pdev)) {
rc = PTR_ERR(monwriter_pdev);
goto out_driver;
}
/*
* misc_register() has to be the last action in module_init(), because
* file operations will be available right after this.
*/
rc = misc_register(&mon_dev);
if (rc)
goto out_device;
return 0;
out_device:
platform_device_unregister(monwriter_pdev);
out_driver:
platform_driver_unregister(&monwriter_pdrv);
return rc;
}
static void __exit mon_exit(void)
{
misc_deregister(&mon_dev);
platform_device_unregister(monwriter_pdev);
platform_driver_unregister(&monwriter_pdrv);
}
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");