diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/s390/char/vmlogrdr.c | 902 |
1 files changed, 902 insertions, 0 deletions
diff --git a/drivers/s390/char/vmlogrdr.c b/drivers/s390/char/vmlogrdr.c new file mode 100644 index 000000000..58333cb45 --- /dev/null +++ b/drivers/s390/char/vmlogrdr.c @@ -0,0 +1,902 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * character device driver for reading z/VM system service records + * + * + * Copyright IBM Corp. 2004, 2009 + * character device driver for reading z/VM system service records, + * Version 1.0 + * Author(s): Xenia Tkatschow <xenia@us.ibm.com> + * Stefan Weinhuber <wein@de.ibm.com> + * + */ + +#define KMSG_COMPONENT "vmlogrdr" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <linux/atomic.h> +#include <linux/uaccess.h> +#include <asm/cpcmd.h> +#include <asm/debug.h> +#include <asm/ebcdic.h> +#include <net/iucv/iucv.h> +#include <linux/kmod.h> +#include <linux/cdev.h> +#include <linux/device.h> +#include <linux/string.h> + +MODULE_AUTHOR + ("(C) 2004 IBM Corporation by Xenia Tkatschow (xenia@us.ibm.com)\n" + " Stefan Weinhuber (wein@de.ibm.com)"); +MODULE_DESCRIPTION ("Character device driver for reading z/VM " + "system service records."); +MODULE_LICENSE("GPL"); + + +/* + * The size of the buffer for iucv data transfer is one page, + * but in addition to the data we read from iucv we also + * place an integer and some characters into that buffer, + * so the maximum size for record data is a little less then + * one page. + */ +#define NET_BUFFER_SIZE (PAGE_SIZE - sizeof(int) - sizeof(FENCE)) + +/* + * The elements that are concurrently accessed by bottom halves are + * connection_established, iucv_path_severed, local_interrupt_buffer + * and receive_ready. The first three can be protected by + * priv_lock. receive_ready is atomic, so it can be incremented and + * decremented without holding a lock. + * The variable dev_in_use needs to be protected by the lock, since + * it's a flag used by open to make sure that the device is opened only + * by one user at the same time. + */ +struct vmlogrdr_priv_t { + char system_service[8]; + char internal_name[8]; + char recording_name[8]; + struct iucv_path *path; + int connection_established; + int iucv_path_severed; + struct iucv_message local_interrupt_buffer; + atomic_t receive_ready; + int minor_num; + char * buffer; + char * current_position; + int remaining; + ulong residual_length; + int buffer_free; + int dev_in_use; /* 1: already opened, 0: not opened*/ + spinlock_t priv_lock; + struct device *device; + struct device *class_device; + int autorecording; + int autopurge; +}; + + +/* + * File operation structure for vmlogrdr devices + */ +static int vmlogrdr_open(struct inode *, struct file *); +static int vmlogrdr_release(struct inode *, struct file *); +static ssize_t vmlogrdr_read (struct file *filp, char __user *data, + size_t count, loff_t * ppos); + +static const struct file_operations vmlogrdr_fops = { + .owner = THIS_MODULE, + .open = vmlogrdr_open, + .release = vmlogrdr_release, + .read = vmlogrdr_read, + .llseek = no_llseek, +}; + + +static void vmlogrdr_iucv_path_complete(struct iucv_path *, u8 *ipuser); +static void vmlogrdr_iucv_path_severed(struct iucv_path *, u8 *ipuser); +static void vmlogrdr_iucv_message_pending(struct iucv_path *, + struct iucv_message *); + + +static struct iucv_handler vmlogrdr_iucv_handler = { + .path_complete = vmlogrdr_iucv_path_complete, + .path_severed = vmlogrdr_iucv_path_severed, + .message_pending = vmlogrdr_iucv_message_pending, +}; + + +static DECLARE_WAIT_QUEUE_HEAD(conn_wait_queue); +static DECLARE_WAIT_QUEUE_HEAD(read_wait_queue); + +/* + * pointer to system service private structure + * minor number 0 --> logrec + * minor number 1 --> account + * minor number 2 --> symptom + */ + +static struct vmlogrdr_priv_t sys_ser[] = { + { .system_service = "*LOGREC ", + .internal_name = "logrec", + .recording_name = "EREP", + .minor_num = 0, + .buffer_free = 1, + .priv_lock = __SPIN_LOCK_UNLOCKED(sys_ser[0].priv_lock), + .autorecording = 1, + .autopurge = 1, + }, + { .system_service = "*ACCOUNT", + .internal_name = "account", + .recording_name = "ACCOUNT", + .minor_num = 1, + .buffer_free = 1, + .priv_lock = __SPIN_LOCK_UNLOCKED(sys_ser[1].priv_lock), + .autorecording = 1, + .autopurge = 1, + }, + { .system_service = "*SYMPTOM", + .internal_name = "symptom", + .recording_name = "SYMPTOM", + .minor_num = 2, + .buffer_free = 1, + .priv_lock = __SPIN_LOCK_UNLOCKED(sys_ser[2].priv_lock), + .autorecording = 1, + .autopurge = 1, + } +}; + +#define MAXMINOR ARRAY_SIZE(sys_ser) + +static char FENCE[] = {"EOR"}; +static int vmlogrdr_major = 0; +static struct cdev *vmlogrdr_cdev = NULL; +static int recording_class_AB; + + +static void vmlogrdr_iucv_path_complete(struct iucv_path *path, u8 *ipuser) +{ + struct vmlogrdr_priv_t * logptr = path->private; + + spin_lock(&logptr->priv_lock); + logptr->connection_established = 1; + spin_unlock(&logptr->priv_lock); + wake_up(&conn_wait_queue); +} + + +static void vmlogrdr_iucv_path_severed(struct iucv_path *path, u8 *ipuser) +{ + struct vmlogrdr_priv_t * logptr = path->private; + u8 reason = (u8) ipuser[8]; + + pr_err("vmlogrdr: connection severed with reason %i\n", reason); + + iucv_path_sever(path, NULL); + kfree(path); + logptr->path = NULL; + + spin_lock(&logptr->priv_lock); + logptr->connection_established = 0; + logptr->iucv_path_severed = 1; + spin_unlock(&logptr->priv_lock); + + wake_up(&conn_wait_queue); + /* just in case we're sleeping waiting for a record */ + wake_up_interruptible(&read_wait_queue); +} + + +static void vmlogrdr_iucv_message_pending(struct iucv_path *path, + struct iucv_message *msg) +{ + struct vmlogrdr_priv_t * logptr = path->private; + + /* + * This function is the bottom half so it should be quick. + * Copy the external interrupt data into our local eib and increment + * the usage count + */ + spin_lock(&logptr->priv_lock); + memcpy(&logptr->local_interrupt_buffer, msg, sizeof(*msg)); + atomic_inc(&logptr->receive_ready); + spin_unlock(&logptr->priv_lock); + wake_up_interruptible(&read_wait_queue); +} + + +static int vmlogrdr_get_recording_class_AB(void) +{ + static const char cp_command[] = "QUERY COMMAND RECORDING "; + char cp_response[80]; + char *tail; + int len,i; + + cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); + len = strnlen(cp_response,sizeof(cp_response)); + // now the parsing + tail=strnchr(cp_response,len,'='); + if (!tail) + return 0; + tail++; + if (!strncmp("ANY",tail,3)) + return 1; + if (!strncmp("NONE",tail,4)) + return 0; + /* + * expect comma separated list of classes here, if one of them + * is A or B return 1 otherwise 0 + */ + for (i=tail-cp_response; i<len; i++) + if ( cp_response[i]=='A' || cp_response[i]=='B' ) + return 1; + return 0; +} + + +static int vmlogrdr_recording(struct vmlogrdr_priv_t * logptr, + int action, int purge) +{ + + char cp_command[80]; + char cp_response[160]; + char *onoff, *qid_string; + int rc; + + onoff = ((action == 1) ? "ON" : "OFF"); + qid_string = ((recording_class_AB == 1) ? " QID * " : ""); + + /* + * The recording commands needs to be called with option QID + * for guests that have previlege classes A or B. + * Purging has to be done as separate step, because recording + * can't be switched on as long as records are on the queue. + * Doing both at the same time doesn't work. + */ + if (purge && (action == 1)) { + memset(cp_command, 0x00, sizeof(cp_command)); + memset(cp_response, 0x00, sizeof(cp_response)); + snprintf(cp_command, sizeof(cp_command), + "RECORDING %s PURGE %s", + logptr->recording_name, + qid_string); + cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); + } + + memset(cp_command, 0x00, sizeof(cp_command)); + memset(cp_response, 0x00, sizeof(cp_response)); + snprintf(cp_command, sizeof(cp_command), "RECORDING %s %s %s", + logptr->recording_name, + onoff, + qid_string); + cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); + /* The recording command will usually answer with 'Command complete' + * on success, but when the specific service was never connected + * before then there might be an additional informational message + * 'HCPCRC8072I Recording entry not found' before the + * 'Command complete'. So I use strstr rather then the strncmp. + */ + if (strstr(cp_response,"Command complete")) + rc = 0; + else + rc = -EIO; + /* + * If we turn recording off, we have to purge any remaining records + * afterwards, as a large number of queued records may impact z/VM + * performance. + */ + if (purge && (action == 0)) { + memset(cp_command, 0x00, sizeof(cp_command)); + memset(cp_response, 0x00, sizeof(cp_response)); + snprintf(cp_command, sizeof(cp_command), + "RECORDING %s PURGE %s", + logptr->recording_name, + qid_string); + cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); + } + + return rc; +} + + +static int vmlogrdr_open (struct inode *inode, struct file *filp) +{ + int dev_num = 0; + struct vmlogrdr_priv_t * logptr = NULL; + int connect_rc = 0; + int ret; + + dev_num = iminor(inode); + if (dev_num >= MAXMINOR) + return -ENODEV; + logptr = &sys_ser[dev_num]; + + /* + * only allow for blocking reads to be open + */ + if (filp->f_flags & O_NONBLOCK) + return -EOPNOTSUPP; + + /* Besure this device hasn't already been opened */ + spin_lock_bh(&logptr->priv_lock); + if (logptr->dev_in_use) { + spin_unlock_bh(&logptr->priv_lock); + return -EBUSY; + } + logptr->dev_in_use = 1; + logptr->connection_established = 0; + logptr->iucv_path_severed = 0; + atomic_set(&logptr->receive_ready, 0); + logptr->buffer_free = 1; + spin_unlock_bh(&logptr->priv_lock); + + /* set the file options */ + filp->private_data = logptr; + + /* start recording for this service*/ + if (logptr->autorecording) { + ret = vmlogrdr_recording(logptr,1,logptr->autopurge); + if (ret) + pr_warn("vmlogrdr: failed to start recording automatically\n"); + } + + /* create connection to the system service */ + logptr->path = iucv_path_alloc(10, 0, GFP_KERNEL); + if (!logptr->path) + goto out_dev; + connect_rc = iucv_path_connect(logptr->path, &vmlogrdr_iucv_handler, + logptr->system_service, NULL, NULL, + logptr); + if (connect_rc) { + pr_err("vmlogrdr: iucv connection to %s " + "failed with rc %i \n", + logptr->system_service, connect_rc); + goto out_path; + } + + /* We've issued the connect and now we must wait for a + * ConnectionComplete or ConnectinSevered Interrupt + * before we can continue to process. + */ + wait_event(conn_wait_queue, (logptr->connection_established) + || (logptr->iucv_path_severed)); + if (logptr->iucv_path_severed) + goto out_record; + nonseekable_open(inode, filp); + return 0; + +out_record: + if (logptr->autorecording) + vmlogrdr_recording(logptr,0,logptr->autopurge); +out_path: + kfree(logptr->path); /* kfree(NULL) is ok. */ + logptr->path = NULL; +out_dev: + logptr->dev_in_use = 0; + return -EIO; +} + + +static int vmlogrdr_release (struct inode *inode, struct file *filp) +{ + int ret; + + struct vmlogrdr_priv_t * logptr = filp->private_data; + + iucv_path_sever(logptr->path, NULL); + kfree(logptr->path); + logptr->path = NULL; + if (logptr->autorecording) { + ret = vmlogrdr_recording(logptr,0,logptr->autopurge); + if (ret) + pr_warn("vmlogrdr: failed to stop recording automatically\n"); + } + logptr->dev_in_use = 0; + + return 0; +} + + +static int vmlogrdr_receive_data(struct vmlogrdr_priv_t *priv) +{ + int rc, *temp; + /* we need to keep track of two data sizes here: + * The number of bytes we need to receive from iucv and + * the total number of bytes we actually write into the buffer. + */ + int user_data_count, iucv_data_count; + char * buffer; + + if (atomic_read(&priv->receive_ready)) { + spin_lock_bh(&priv->priv_lock); + if (priv->residual_length){ + /* receive second half of a record */ + iucv_data_count = priv->residual_length; + user_data_count = 0; + buffer = priv->buffer; + } else { + /* receive a new record: + * We need to return the total length of the record + * + size of FENCE in the first 4 bytes of the buffer. + */ + iucv_data_count = priv->local_interrupt_buffer.length; + user_data_count = sizeof(int); + temp = (int*)priv->buffer; + *temp= iucv_data_count + sizeof(FENCE); + buffer = priv->buffer + sizeof(int); + } + /* + * If the record is bigger than our buffer, we receive only + * a part of it. We can get the rest later. + */ + if (iucv_data_count > NET_BUFFER_SIZE) + iucv_data_count = NET_BUFFER_SIZE; + rc = iucv_message_receive(priv->path, + &priv->local_interrupt_buffer, + 0, buffer, iucv_data_count, + &priv->residual_length); + spin_unlock_bh(&priv->priv_lock); + /* An rc of 5 indicates that the record was bigger than + * the buffer, which is OK for us. A 9 indicates that the + * record was purged befor we could receive it. + */ + if (rc == 5) + rc = 0; + if (rc == 9) + atomic_set(&priv->receive_ready, 0); + } else { + rc = 1; + } + if (!rc) { + priv->buffer_free = 0; + user_data_count += iucv_data_count; + priv->current_position = priv->buffer; + if (priv->residual_length == 0){ + /* the whole record has been captured, + * now add the fence */ + atomic_dec(&priv->receive_ready); + buffer = priv->buffer + user_data_count; + memcpy(buffer, FENCE, sizeof(FENCE)); + user_data_count += sizeof(FENCE); + } + priv->remaining = user_data_count; + } + + return rc; +} + + +static ssize_t vmlogrdr_read(struct file *filp, char __user *data, + size_t count, loff_t * ppos) +{ + int rc; + struct vmlogrdr_priv_t * priv = filp->private_data; + + while (priv->buffer_free) { + rc = vmlogrdr_receive_data(priv); + if (rc) { + rc = wait_event_interruptible(read_wait_queue, + atomic_read(&priv->receive_ready)); + if (rc) + return rc; + } + } + /* copy only up to end of record */ + if (count > priv->remaining) + count = priv->remaining; + + if (copy_to_user(data, priv->current_position, count)) + return -EFAULT; + + *ppos += count; + priv->current_position += count; + priv->remaining -= count; + + /* if all data has been transferred, set buffer free */ + if (priv->remaining == 0) + priv->buffer_free = 1; + + return count; +} + +static ssize_t vmlogrdr_autopurge_store(struct device * dev, + struct device_attribute *attr, + const char * buf, size_t count) +{ + struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev); + ssize_t ret = count; + + switch (buf[0]) { + case '0': + priv->autopurge=0; + break; + case '1': + priv->autopurge=1; + break; + default: + ret = -EINVAL; + } + return ret; +} + + +static ssize_t vmlogrdr_autopurge_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev); + return sprintf(buf, "%u\n", priv->autopurge); +} + + +static DEVICE_ATTR(autopurge, 0644, vmlogrdr_autopurge_show, + vmlogrdr_autopurge_store); + + +static ssize_t vmlogrdr_purge_store(struct device * dev, + struct device_attribute *attr, + const char * buf, size_t count) +{ + + char cp_command[80]; + char cp_response[80]; + struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev); + + if (buf[0] != '1') + return -EINVAL; + + memset(cp_command, 0x00, sizeof(cp_command)); + memset(cp_response, 0x00, sizeof(cp_response)); + + /* + * The recording command needs to be called with option QID + * for guests that have previlege classes A or B. + * Other guests will not recognize the command and we have to + * issue the same command without the QID parameter. + */ + + if (recording_class_AB) + snprintf(cp_command, sizeof(cp_command), + "RECORDING %s PURGE QID * ", + priv->recording_name); + else + snprintf(cp_command, sizeof(cp_command), + "RECORDING %s PURGE ", + priv->recording_name); + + cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); + + return count; +} + + +static DEVICE_ATTR(purge, 0200, NULL, vmlogrdr_purge_store); + + +static ssize_t vmlogrdr_autorecording_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev); + ssize_t ret = count; + + switch (buf[0]) { + case '0': + priv->autorecording=0; + break; + case '1': + priv->autorecording=1; + break; + default: + ret = -EINVAL; + } + return ret; +} + + +static ssize_t vmlogrdr_autorecording_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev); + return sprintf(buf, "%u\n", priv->autorecording); +} + + +static DEVICE_ATTR(autorecording, 0644, vmlogrdr_autorecording_show, + vmlogrdr_autorecording_store); + + +static ssize_t vmlogrdr_recording_store(struct device * dev, + struct device_attribute *attr, + const char * buf, size_t count) +{ + struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev); + ssize_t ret; + + switch (buf[0]) { + case '0': + ret = vmlogrdr_recording(priv,0,0); + break; + case '1': + ret = vmlogrdr_recording(priv,1,0); + break; + default: + ret = -EINVAL; + } + if (ret) + return ret; + else + return count; + +} + + +static DEVICE_ATTR(recording, 0200, NULL, vmlogrdr_recording_store); + + +static ssize_t recording_status_show(struct device_driver *driver, char *buf) +{ + static const char cp_command[] = "QUERY RECORDING "; + int len; + + cpcmd(cp_command, buf, 4096, NULL); + len = strlen(buf); + return len; +} +static DRIVER_ATTR_RO(recording_status); +static struct attribute *vmlogrdr_drv_attrs[] = { + &driver_attr_recording_status.attr, + NULL, +}; +static struct attribute_group vmlogrdr_drv_attr_group = { + .attrs = vmlogrdr_drv_attrs, +}; +static const struct attribute_group *vmlogrdr_drv_attr_groups[] = { + &vmlogrdr_drv_attr_group, + NULL, +}; + +static struct attribute *vmlogrdr_attrs[] = { + &dev_attr_autopurge.attr, + &dev_attr_purge.attr, + &dev_attr_autorecording.attr, + &dev_attr_recording.attr, + NULL, +}; +static struct attribute_group vmlogrdr_attr_group = { + .attrs = vmlogrdr_attrs, +}; +static const struct attribute_group *vmlogrdr_attr_groups[] = { + &vmlogrdr_attr_group, + NULL, +}; + +static int vmlogrdr_pm_prepare(struct device *dev) +{ + int rc; + struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev); + + rc = 0; + if (priv) { + spin_lock_bh(&priv->priv_lock); + if (priv->dev_in_use) + rc = -EBUSY; + spin_unlock_bh(&priv->priv_lock); + } + if (rc) + pr_err("vmlogrdr: device %s is busy. Refuse to suspend.\n", + dev_name(dev)); + return rc; +} + + +static const struct dev_pm_ops vmlogrdr_pm_ops = { + .prepare = vmlogrdr_pm_prepare, +}; + +static struct class *vmlogrdr_class; +static struct device_driver vmlogrdr_driver = { + .name = "vmlogrdr", + .bus = &iucv_bus, + .pm = &vmlogrdr_pm_ops, + .groups = vmlogrdr_drv_attr_groups, +}; + +static int vmlogrdr_register_driver(void) +{ + int ret; + + /* Register with iucv driver */ + ret = iucv_register(&vmlogrdr_iucv_handler, 1); + if (ret) + goto out; + + ret = driver_register(&vmlogrdr_driver); + if (ret) + goto out_iucv; + + vmlogrdr_class = class_create(THIS_MODULE, "vmlogrdr"); + if (IS_ERR(vmlogrdr_class)) { + ret = PTR_ERR(vmlogrdr_class); + vmlogrdr_class = NULL; + goto out_driver; + } + return 0; + +out_driver: + driver_unregister(&vmlogrdr_driver); +out_iucv: + iucv_unregister(&vmlogrdr_iucv_handler, 1); +out: + return ret; +} + + +static void vmlogrdr_unregister_driver(void) +{ + class_destroy(vmlogrdr_class); + vmlogrdr_class = NULL; + driver_unregister(&vmlogrdr_driver); + iucv_unregister(&vmlogrdr_iucv_handler, 1); +} + + +static int vmlogrdr_register_device(struct vmlogrdr_priv_t *priv) +{ + struct device *dev; + int ret; + + dev = kzalloc(sizeof(struct device), GFP_KERNEL); + if (dev) { + dev_set_name(dev, "%s", priv->internal_name); + dev->bus = &iucv_bus; + dev->parent = iucv_root; + dev->driver = &vmlogrdr_driver; + dev->groups = vmlogrdr_attr_groups; + dev_set_drvdata(dev, priv); + /* + * The release function could be called after the + * module has been unloaded. It's _only_ task is to + * free the struct. Therefore, we specify kfree() + * directly here. (Probably a little bit obfuscating + * but legitime ...). + */ + dev->release = (void (*)(struct device *))kfree; + } else + return -ENOMEM; + ret = device_register(dev); + if (ret) { + put_device(dev); + return ret; + } + + priv->class_device = device_create(vmlogrdr_class, dev, + MKDEV(vmlogrdr_major, + priv->minor_num), + priv, "%s", dev_name(dev)); + if (IS_ERR(priv->class_device)) { + ret = PTR_ERR(priv->class_device); + priv->class_device=NULL; + device_unregister(dev); + return ret; + } + priv->device = dev; + return 0; +} + + +static int vmlogrdr_unregister_device(struct vmlogrdr_priv_t *priv) +{ + device_destroy(vmlogrdr_class, MKDEV(vmlogrdr_major, priv->minor_num)); + if (priv->device != NULL) { + device_unregister(priv->device); + priv->device=NULL; + } + return 0; +} + + +static int vmlogrdr_register_cdev(dev_t dev) +{ + int rc = 0; + vmlogrdr_cdev = cdev_alloc(); + if (!vmlogrdr_cdev) { + return -ENOMEM; + } + vmlogrdr_cdev->owner = THIS_MODULE; + vmlogrdr_cdev->ops = &vmlogrdr_fops; + rc = cdev_add(vmlogrdr_cdev, dev, MAXMINOR); + if (!rc) + return 0; + + // cleanup: cdev is not fully registered, no cdev_del here! + kobject_put(&vmlogrdr_cdev->kobj); + vmlogrdr_cdev=NULL; + return rc; +} + + +static void vmlogrdr_cleanup(void) +{ + int i; + + if (vmlogrdr_cdev) { + cdev_del(vmlogrdr_cdev); + vmlogrdr_cdev=NULL; + } + for (i=0; i < MAXMINOR; ++i ) { + vmlogrdr_unregister_device(&sys_ser[i]); + free_page((unsigned long)sys_ser[i].buffer); + } + vmlogrdr_unregister_driver(); + if (vmlogrdr_major) { + unregister_chrdev_region(MKDEV(vmlogrdr_major, 0), MAXMINOR); + vmlogrdr_major=0; + } +} + + +static int __init vmlogrdr_init(void) +{ + int rc; + int i; + dev_t dev; + + if (! MACHINE_IS_VM) { + pr_err("not running under VM, driver not loaded.\n"); + return -ENODEV; + } + + recording_class_AB = vmlogrdr_get_recording_class_AB(); + + rc = alloc_chrdev_region(&dev, 0, MAXMINOR, "vmlogrdr"); + if (rc) + return rc; + vmlogrdr_major = MAJOR(dev); + + rc=vmlogrdr_register_driver(); + if (rc) + goto cleanup; + + for (i=0; i < MAXMINOR; ++i ) { + sys_ser[i].buffer = (char *) get_zeroed_page(GFP_KERNEL | GFP_DMA); + if (!sys_ser[i].buffer) { + rc = -ENOMEM; + break; + } + sys_ser[i].current_position = sys_ser[i].buffer; + rc=vmlogrdr_register_device(&sys_ser[i]); + if (rc) + break; + } + if (rc) + goto cleanup; + + rc = vmlogrdr_register_cdev(dev); + if (rc) + goto cleanup; + return 0; + +cleanup: + vmlogrdr_cleanup(); + return rc; +} + + +static void __exit vmlogrdr_exit(void) +{ + vmlogrdr_cleanup(); + return; +} + + +module_init(vmlogrdr_init); +module_exit(vmlogrdr_exit); |