Commit 31b58088 authored by Melissa Howland's avatar Melissa Howland Committed by Martin Schwidefsky
Browse files

[S390] Linux API for writing z/VM APPLDATA Monitor records.



This patch delivers a new Linux API in the form of a misc char
device that is useable from user space and allows write access
to the z/VM APPLDATA Monitor Records collected by the *MONITOR
System Service of z/VM.
Signed-off-by: default avatarMelissa Howland <melissah@us.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent e620c494
......@@ -428,6 +428,7 @@ CONFIG_S390_TAPE_34XX=m
# CONFIG_VMLOGRDR is not set
# CONFIG_VMCP is not set
# CONFIG_MONREADER is not set
CONFIG_MONWRITER=m
#
# Cryptographic devices
......
......@@ -213,6 +213,12 @@ config MONREADER
help
Character device driver for reading z/VM monitor service records
config MONWRITER
tristate "API for writing z/VM monitor service records"
default "m"
help
Character device driver for writing z/VM monitor service records
endmenu
menu "Cryptographic devices"
......
......@@ -28,3 +28,4 @@ obj-$(CONFIG_S390_TAPE) += tape.o tape_class.o
obj-$(CONFIG_S390_TAPE_34XX) += tape_34xx.o
obj-$(CONFIG_S390_TAPE_3590) += tape_3590.o
obj-$(CONFIG_MONREADER) += monreader.o
obj-$(CONFIG_MONWRITER) += monwriter.o
/*
* 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 4024
static int mon_max_bufs = 255;
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;
int mon_buf_count;
};
/*
* 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 inline 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.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 = 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);
monpriv->mon_buf_count--;
kfree(monbuf->data);
kfree(monbuf);
monbuf = NULL;
}
} else {
if (monpriv->mon_buf_count >= mon_max_bufs)
return -ENOSPC;
monbuf = kzalloc(sizeof(struct mon_buf), GFP_KERNEL);
if (!monbuf)
return -ENOMEM;
monbuf->data = kzalloc(monbuf->hdr.datalen,
GFP_KERNEL | GFP_DMA);
if (!monbuf->data) {
kfree(monbuf);
return -ENOMEM;
}
monbuf->hdr = *monhdr;
list_add_tail(&monbuf->list, &monpriv->list);
monpriv->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);
monpriv->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 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");
include include/asm-generic/Kbuild.asm
unifdef-y += cmb.h debug.h
header-y += dasd.h qeth.h tape390.h ucontext.h vtoc.h z90crypt.h
header-y += dasd.h monwriter.h qeth.h tape390.h ucontext.h vtoc.h z90crypt.h
/*
* include/asm-s390/monwriter.h
*
* Copyright (C) IBM Corp. 2006
* Character device driver for writing z/VM APPLDATA monitor records
* Version 1.0
* Author(s): Melissa Howland <melissah@us.ibm.com>
*
*/
#ifndef _ASM_390_MONWRITER_H
#define _ASM_390_MONWRITER_H
/* mon_function values */
#define MONWRITE_START_INTERVAL 0x00 /* start interval recording */
#define MONWRITE_STOP_INTERVAL 0x01 /* stop interval or config recording */
#define MONWRITE_GEN_EVENT 0x02 /* generate event record */
#define MONWRITE_START_CONFIG 0x03 /* start configuration recording */
/* the header the app uses in its write() data */
struct monwrite_hdr {
unsigned char mon_function;
unsigned short applid;
unsigned char record_num;
unsigned short version;
unsigned short release;
unsigned short mod_level;
unsigned short datalen;
unsigned char hdrlen;
} __attribute__((packed));
#endif /* _ASM_390_MONWRITER_H */
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