diff options
author | Melissa Howland <melissah@us.ibm.com> | 2006-09-20 13:59:34 (GMT) |
---|---|---|
committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2006-09-20 13:59:34 (GMT) |
commit | 31b58088292c7f00f0b81088bfb557285b0b6247 (patch) | |
tree | 7ce82a49cbf3ad0c28feb63d15b35a6c97d668a0 /drivers/s390/char/monwriter.c | |
parent | e620c4940002348417e8d317d65bc7b152646493 (diff) | |
download | linux-31b58088292c7f00f0b81088bfb557285b0b6247.tar.xz |
[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: Melissa Howland <melissah@us.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/char/monwriter.c')
-rw-r--r-- | drivers/s390/char/monwriter.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/drivers/s390/char/monwriter.c b/drivers/s390/char/monwriter.c new file mode 100644 index 0000000..1e3939a --- /dev/null +++ b/drivers/s390/char/monwriter.c @@ -0,0 +1,292 @@ +/* + * 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"); |