[deliverable/linux.git] / drivers / s390 / char / monwriter.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/smp_lock.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 <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;
	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;
	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;
	lock_kernel();
	INIT_LIST_HEAD(&monpriv->list);
	monpriv->hdr_to_read = sizeof(monpriv->hdr);
	mutex_init(&monpriv->thread_mutex);
	filp->private_data = monpriv;
	unlock_kernel();
	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;

	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,
};

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");
Commit	Line	Data
31b58088 MH	1	/*
	2	* drivers/s390/char/monwriter.c
	3	*
	4	* Character device driver for writing z/VM *MONITOR service records.
	5	*
	6	* Copyright (C) IBM Corp. 2006
	7	*
	8	* Author(s): Melissa Howland <Melissa.Howland@us.ibm.com>
	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/moduleparam.h>
	13	#include <linux/init.h>
	14	#include <linux/errno.h>
dca67e9d	15	#include <linux/smp_lock.h>
31b58088 MH	16	#include <linux/types.h>
	17	#include <linux/kernel.h>
	18	#include <linux/miscdevice.h>
	19	#include <linux/ctype.h>
	20	#include <linux/poll.h>
cbea66d9	21	#include <linux/mutex.h>
31b58088 MH	22	#include <asm/uaccess.h>
	23	#include <asm/ebcdic.h>
	24	#include <asm/io.h>
	25	#include <asm/appldata.h>
	26	#include <asm/monwriter.h>
	27
524a237e	28	#define MONWRITE_MAX_DATALEN 4010
31b58088 MH	29
31b58088 MH	30	static int mon_max_bufs = 255;
2d103d5a	31	static int mon_buf_count;
31b58088 MH	32
	33	struct mon_buf {
	34	struct list_head list;
	35	struct monwrite_hdr hdr;
	36	int diag_done;
	37	char *data;
	38	};
	39
	40	struct mon_private {
	41	struct list_head list;
	42	struct monwrite_hdr hdr;
	43	size_t hdr_to_read;
	44	size_t data_to_read;
	45	struct mon_buf *current_buf;
cbea66d9	46	struct mutex thread_mutex;
31b58088 MH	47	};
	48
	49	/*
	50	* helper functions
	51	*/
	52
	53	static int monwrite_diag(struct monwrite_hdr myhdr, char buffer, int fcn)
	54	{
	55	struct appldata_product_id id;
	56	int rc;
	57
	58	strcpy(id.prod_nr, "LNXAPPL");
	59	id.prod_fn = myhdr->applid;
	60	id.record_nr = myhdr->record_num;
	61	id.version_nr = myhdr->version;
	62	id.release_nr = myhdr->release;
	63	id.mod_lvl = myhdr->mod_level;
	64	rc = appldata_asm(&id, fcn, (void *) buffer, myhdr->datalen);
	65	if (rc <= 0)
	66	return rc;
	67	if (rc == 5)
	68	return -EPERM;
	69	printk("DIAG X'DC' error with return code: %i\n", rc);
	70	return -EINVAL;
	71	}
	72
4d284cac HC	73	static struct mon_buf monwrite_find_hdr(struct mon_private monpriv,
4d284cac HC	74	struct monwrite_hdr *monhdr)
31b58088 MH	75	{
	76	struct mon_buf entry, next;
	77
	78	list_for_each_entry_safe(entry, next, &monpriv->list, list)
2c91971f MH	79	if ((entry->hdr.mon_function == monhdr->mon_function \|\|
	80	monhdr->mon_function == MONWRITE_STOP_INTERVAL) &&
	81	entry->hdr.applid == monhdr->applid &&
31b58088 MH	82	entry->hdr.record_num == monhdr->record_num &&
	83	entry->hdr.version == monhdr->version &&
	84	entry->hdr.release == monhdr->release &&
	85	entry->hdr.mod_level == monhdr->mod_level)
	86	return entry;
2c91971f	87
31b58088 MH	88	return NULL;
	89	}
	90
	91	static int monwrite_new_hdr(struct mon_private *monpriv)
	92	{
	93	struct monwrite_hdr *monhdr = &monpriv->hdr;
	94	struct mon_buf *monbuf;
	95	int rc;
	96
	97	if (monhdr->datalen > MONWRITE_MAX_DATALEN \|\|
	98	monhdr->mon_function > MONWRITE_START_CONFIG \|\|
	99	monhdr->hdrlen != sizeof(struct monwrite_hdr))
	100	return -EINVAL;
2c91971f MH	101	monbuf = NULL;
	102	if (monhdr->mon_function != MONWRITE_GEN_EVENT)
	103	monbuf = monwrite_find_hdr(monpriv, monhdr);
31b58088 MH	104	if (monbuf) {
	105	if (monhdr->mon_function == MONWRITE_STOP_INTERVAL) {
	106	monhdr->datalen = monbuf->hdr.datalen;
	107	rc = monwrite_diag(monhdr, monbuf->data,
	108	APPLDATA_STOP_REC);
	109	list_del(&monbuf->list);
2d103d5a	110	mon_buf_count--;
31b58088 MH	111	kfree(monbuf->data);
	112	kfree(monbuf);
	113	monbuf = NULL;
	114	}
2c91971f	115	} else if (monhdr->mon_function != MONWRITE_STOP_INTERVAL) {
2d103d5a	116	if (mon_buf_count >= mon_max_bufs)
31b58088 MH	117	return -ENOSPC;
	118	monbuf = kzalloc(sizeof(struct mon_buf), GFP_KERNEL);
	119	if (!monbuf)
	120	return -ENOMEM;
715d854b	121	monbuf->data = kzalloc(monhdr->datalen,
31b58088 MH	122	GFP_KERNEL \| GFP_DMA);
	123	if (!monbuf->data) {
	124	kfree(monbuf);
	125	return -ENOMEM;
	126	}
	127	monbuf->hdr = *monhdr;
	128	list_add_tail(&monbuf->list, &monpriv->list);
2c91971f MH	129	if (monhdr->mon_function != MONWRITE_GEN_EVENT)
2c91971f MH	130	mon_buf_count++;
31b58088 MH	131	}
	132	monpriv->current_buf = monbuf;
	133	return 0;
	134	}
	135
	136	static int monwrite_new_data(struct mon_private *monpriv)
	137	{
	138	struct monwrite_hdr *monhdr = &monpriv->hdr;
	139	struct mon_buf *monbuf = monpriv->current_buf;
	140	int rc = 0;
	141
	142	switch (monhdr->mon_function) {
	143	case MONWRITE_START_INTERVAL:
	144	if (!monbuf->diag_done) {
	145	rc = monwrite_diag(monhdr, monbuf->data,
	146	APPLDATA_START_INTERVAL_REC);
	147	monbuf->diag_done = 1;
	148	}
	149	break;
	150	case MONWRITE_START_CONFIG:
	151	if (!monbuf->diag_done) {
	152	rc = monwrite_diag(monhdr, monbuf->data,
	153	APPLDATA_START_CONFIG_REC);
	154	monbuf->diag_done = 1;
	155	}
	156	break;
	157	case MONWRITE_GEN_EVENT:
	158	rc = monwrite_diag(monhdr, monbuf->data,
	159	APPLDATA_GEN_EVENT_REC);
	160	list_del(&monpriv->current_buf->list);
	161	kfree(monpriv->current_buf->data);
	162	kfree(monpriv->current_buf);
	163	monpriv->current_buf = NULL;
	164	break;
	165	default:
	166	/* monhdr->mon_function is checked in monwrite_new_hdr */
	167	BUG();
	168	}
	169	return rc;
	170	}
	171
	172	/*
	173	* file operations
	174	*/
	175
	176	static int monwrite_open(struct inode inode, struct file filp)
	177	{
	178	struct mon_private *monpriv;
	179
	180	monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
	181	if (!monpriv)
	182	return -ENOMEM;
dca67e9d	183	lock_kernel();
31b58088 MH	184	INIT_LIST_HEAD(&monpriv->list);
31b58088 MH	185	monpriv->hdr_to_read = sizeof(monpriv->hdr);
cbea66d9	186	mutex_init(&monpriv->thread_mutex);
31b58088	187	filp->private_data = monpriv;
dca67e9d	188	unlock_kernel();
31b58088 MH	189	return nonseekable_open(inode, filp);
	190	}
	191
	192	static int monwrite_close(struct inode inode, struct file filp)
	193	{
	194	struct mon_private *monpriv = filp->private_data;
	195	struct mon_buf entry, next;
	196
	197	list_for_each_entry_safe(entry, next, &monpriv->list, list) {
	198	if (entry->hdr.mon_function != MONWRITE_GEN_EVENT)
	199	monwrite_diag(&entry->hdr, entry->data,
	200	APPLDATA_STOP_REC);
2d103d5a	201	mon_buf_count--;
31b58088 MH	202	list_del(&entry->list);
	203	kfree(entry->data);
	204	kfree(entry);
	205	}
	206	kfree(monpriv);
	207	return 0;
	208	}
	209
	210	static ssize_t monwrite_write(struct file filp, const char __user data,
	211	size_t count, loff_t *ppos)
	212	{
	213	struct mon_private *monpriv = filp->private_data;
	214	size_t len, written;
	215	void *to;
	216	int rc;
	217
cbea66d9	218	mutex_lock(&monpriv->thread_mutex);
31b58088 MH	219	for (written = 0; written < count; ) {
	220	if (monpriv->hdr_to_read) {
	221	len = min(count - written, monpriv->hdr_to_read);
	222	to = (char *) &monpriv->hdr +
	223	sizeof(monpriv->hdr) - monpriv->hdr_to_read;
	224	if (copy_from_user(to, data + written, len)) {
	225	rc = -EFAULT;
	226	goto out_error;
	227	}
	228	monpriv->hdr_to_read -= len;
	229	written += len;
	230	if (monpriv->hdr_to_read > 0)
	231	continue;
	232	rc = monwrite_new_hdr(monpriv);
	233	if (rc)
	234	goto out_error;
	235	monpriv->data_to_read = monpriv->current_buf ?
	236	monpriv->current_buf->hdr.datalen : 0;
	237	}
	238
	239	if (monpriv->data_to_read) {
	240	len = min(count - written, monpriv->data_to_read);
	241	to = monpriv->current_buf->data +
	242	monpriv->hdr.datalen - monpriv->data_to_read;
	243	if (copy_from_user(to, data + written, len)) {
	244	rc = -EFAULT;
	245	goto out_error;
	246	}
	247	monpriv->data_to_read -= len;
	248	written += len;
	249	if (monpriv->data_to_read > 0)
	250	continue;
	251	rc = monwrite_new_data(monpriv);
	252	if (rc)
	253	goto out_error;
	254	}
	255	monpriv->hdr_to_read = sizeof(monpriv->hdr);
	256	}
cbea66d9	257	mutex_unlock(&monpriv->thread_mutex);
31b58088 MH	258	return written;
	259
	260	out_error:
	261	monpriv->data_to_read = 0;
	262	monpriv->hdr_to_read = sizeof(struct monwrite_hdr);
cbea66d9	263	mutex_unlock(&monpriv->thread_mutex);
31b58088 MH	264	return rc;
	265	}
	266
d54b1fdb	267	static const struct file_operations monwrite_fops = {
31b58088 MH	268	.owner = THIS_MODULE,
	269	.open = &monwrite_open,
	270	.release = &monwrite_close,
	271	.write = &monwrite_write,
	272	};
	273
	274	static struct miscdevice mon_dev = {
	275	.name = "monwriter",
	276	.fops = &monwrite_fops,
	277	.minor = MISC_DYNAMIC_MINOR,
	278	};
	279
	280	/*
	281	* module init/exit
	282	*/
	283
	284	static int __init mon_init(void)
	285	{
	286	if (MACHINE_IS_VM)
	287	return misc_register(&mon_dev);
	288	else
	289	return -ENODEV;
	290	}
	291
	292	static void __exit mon_exit(void)
	293	{
	294	WARN_ON(misc_deregister(&mon_dev) != 0);
	295	}
	296
	297	module_init(mon_init);
	298	module_exit(mon_exit);
	299
	300	module_param_named(max_bufs, mon_max_bufs, int, 0644);
ceb3dfba	301	MODULE_PARM_DESC(max_bufs, "Maximum number of sample monitor data buffers "
31b58088 MH	302	"that can be active at one time");
	303
	304	MODULE_AUTHOR("Melissa Howland <Melissa.Howland@us.ibm.com>");
	305	MODULE_DESCRIPTION("Character device driver for writing z/VM "
	306	"APPLDATA monitor records.");
	307	MODULE_LICENSE("GPL");