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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/s390/char/vmlogrdr.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/s390/char/vmlogrdr.c')
-rw-r--r-- | drivers/s390/char/vmlogrdr.c | 920 |
1 files changed, 920 insertions, 0 deletions
diff --git a/drivers/s390/char/vmlogrdr.c b/drivers/s390/char/vmlogrdr.c new file mode 100644 index 0000000..edf50d2 --- /dev/null +++ b/drivers/s390/char/vmlogrdr.c @@ -0,0 +1,920 @@ +/* + * drivers/s390/char/vmlogrdr.c + * character device driver for reading z/VM system service records + * + * + * Copyright (C) 2004 IBM Corporation + * 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> + * + */ +#include <linux/module.h> +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <asm/atomic.h> +#include <asm/uaccess.h> +#include <asm/cpcmd.h> +#include <asm/debug.h> +#include <asm/ebcdic.h> +#include "../net/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]; + u16 pathid; + int connection_established; + int iucv_path_severed; + iucv_MessagePending local_interrupt_buffer; + atomic_t receive_ready; + iucv_handle_t iucv_handle; + 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 class_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 *data, size_t count, + loff_t * ppos); + +static struct file_operations vmlogrdr_fops = { + .owner = THIS_MODULE, + .open = vmlogrdr_open, + .release = vmlogrdr_release, + .read = vmlogrdr_read, +}; + + +static u8 iucvMagic[16] = { + 0xF0, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, + 0xF0, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40 +}; + + +static u8 mask[] = { + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff +}; + + +static u8 iucv_host[8] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; + + +static void +vmlogrdr_iucv_ConnectionComplete(iucv_ConnectionComplete *eib, void *pgm_data); +static void +vmlogrdr_iucv_ConnectionSevered(iucv_ConnectionSevered *eib, void *pgm_data); +static void +vmlogrdr_iucv_MessagePending(iucv_MessagePending *eib, void *pgm_data); + + +static iucv_interrupt_ops_t vmlogrdr_iucvops = { + .ConnectionComplete = vmlogrdr_iucv_ConnectionComplete, + .ConnectionSevered = vmlogrdr_iucv_ConnectionSevered, + .MessagePending = vmlogrdr_iucv_MessagePending, +}; + + +DECLARE_WAIT_QUEUE_HEAD(conn_wait_queue); +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, + .autorecording = 1, + .autopurge = 1, + }, + { .system_service = "*ACCOUNT", + .internal_name = "account", + .recording_name = "ACCOUNT", + .minor_num = 1, + .buffer_free = 1, + .priv_lock = SPIN_LOCK_UNLOCKED, + .autorecording = 1, + .autopurge = 1, + }, + { .system_service = "*SYMPTOM", + .internal_name = "symptom", + .recording_name = "SYMPTOM", + .minor_num = 2, + .buffer_free = 1, + .priv_lock = SPIN_LOCK_UNLOCKED, + .autorecording = 1, + .autopurge = 1, + } +}; + +#define MAXMINOR (sizeof(sys_ser)/sizeof(struct vmlogrdr_priv_t)) + +static char FENCE[] = {"EOR"}; +static int vmlogrdr_major = 0; +static struct cdev *vmlogrdr_cdev = NULL; +static int recording_class_AB; + + +static void +vmlogrdr_iucv_ConnectionComplete (iucv_ConnectionComplete * eib, + void * pgm_data) +{ + struct vmlogrdr_priv_t * logptr = pgm_data; + spin_lock(&logptr->priv_lock); + logptr->connection_established = 1; + spin_unlock(&logptr->priv_lock); + wake_up(&conn_wait_queue); + return; +} + + +static void +vmlogrdr_iucv_ConnectionSevered (iucv_ConnectionSevered * eib, void * pgm_data) +{ + u8 reason = (u8) eib->ipuser[8]; + struct vmlogrdr_priv_t * logptr = pgm_data; + + printk (KERN_ERR "vmlogrdr: connection severed with" + " reason %i\n", reason); + + 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_MessagePending (iucv_MessagePending * eib, void * pgm_data) +{ + struct vmlogrdr_priv_t * logptr = pgm_data; + + /* + * 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), eib, sizeof(*eib)); + atomic_inc(&logptr->receive_ready); + spin_unlock(&logptr->priv_lock); + wake_up_interruptible(&read_wait_queue); +} + + +static int +vmlogrdr_get_recording_class_AB(void) { + char cp_command[]="QUERY COMMAND RECORDING "; + char cp_response[80]; + char *tail; + int len,i; + + printk (KERN_DEBUG "vmlogrdr: query command: %s\n", cp_command); + cpcmd(cp_command, cp_response, sizeof(cp_response)); + printk (KERN_DEBUG "vmlogrdr: response: %s", cp_response); + 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; + + memset(cp_command, 0x00, sizeof(cp_command)); + memset(cp_response, 0x00, sizeof(cp_response)); + + 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) { + snprintf(cp_command, sizeof(cp_command), + "RECORDING %s PURGE %s", + logptr->recording_name, + qid_string); + + printk (KERN_DEBUG "vmlogrdr: recording command: %s\n", + cp_command); + cpcmd(cp_command, cp_response, sizeof(cp_response)); + printk (KERN_DEBUG "vmlogrdr: recording response: %s", + cp_response); + } + + 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); + + printk (KERN_DEBUG "vmlogrdr: recording command: %s\n", cp_command); + cpcmd(cp_command, cp_response, sizeof(cp_response)); + printk (KERN_DEBUG "vmlogrdr: recording response: %s", + cp_response); + /* 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")) + return 0; + else + return -EIO; + +} + + +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]; + if (logptr == NULL) + return -ENODEV; + + /* + * only allow for blocking reads to be open + */ + if (filp->f_flags & O_NONBLOCK) + return -ENOSYS; + + /* 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; + } else { + logptr->dev_in_use = 1; + spin_unlock_bh(&logptr->priv_lock); + } + + atomic_set(&logptr->receive_ready, 0); + logptr->buffer_free = 1; + + /* set the file options */ + filp->private_data = logptr; + filp->f_op = &vmlogrdr_fops; + + /* start recording for this service*/ + ret=0; + if (logptr->autorecording) + ret = vmlogrdr_recording(logptr,1,logptr->autopurge); + if (ret) + printk (KERN_WARNING "vmlogrdr: failed to start " + "recording automatically\n"); + + /* Register with iucv driver */ + logptr->iucv_handle = iucv_register_program(iucvMagic, + logptr->system_service, mask, &vmlogrdr_iucvops, + logptr); + + if (logptr->iucv_handle == NULL) { + printk (KERN_ERR "vmlogrdr: failed to register with" + "iucv driver\n"); + goto not_registered; + } + + /* create connection to the system service */ + spin_lock_bh(&logptr->priv_lock); + logptr->connection_established = 0; + logptr->iucv_path_severed = 0; + spin_unlock_bh(&logptr->priv_lock); + + connect_rc = iucv_connect (&(logptr->pathid), 10, iucvMagic, + logptr->system_service, iucv_host, 0, + NULL, NULL, + logptr->iucv_handle, NULL); + if (connect_rc) { + printk (KERN_ERR "vmlogrdr: iucv connection to %s " + "failed with rc %i \n", logptr->system_service, + connect_rc); + goto not_connected; + } + + /* 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 not_connected; + } + + return nonseekable_open(inode, filp); + +not_connected: + iucv_unregister_program(logptr->iucv_handle); + logptr->iucv_handle = NULL; +not_registered: + if (logptr->autorecording) + vmlogrdr_recording(logptr,0,logptr->autopurge); + 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_unregister_program(logptr->iucv_handle); + logptr->iucv_handle = NULL; + + if (logptr->autorecording) { + ret = vmlogrdr_recording(logptr,0,logptr->autopurge); + if (ret) + printk (KERN_WARNING "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.ln1msg2.ipbfln1f; + 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 then 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_receive(priv->pathid, + priv->local_interrupt_buffer.ipmsgid, + priv->local_interrupt_buffer.iptrgcls, + buffer, + iucv_data_count, + NULL, + NULL, + &priv->residual_length); + spin_unlock_bh(&priv->priv_lock); + /* An rc of 5 indicates that the record was bigger then + * 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 *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, const char * buf, size_t count) { + struct vmlogrdr_priv_t *priv = dev->driver_data; + 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, char *buf) { + struct vmlogrdr_priv_t *priv = dev->driver_data; + 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, const char * buf, size_t count) { + + char cp_command[80]; + char cp_response[80]; + struct vmlogrdr_priv_t *priv = dev->driver_data; + + 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); + + printk (KERN_DEBUG "vmlogrdr: recording command: %s\n", cp_command); + cpcmd(cp_command, cp_response, sizeof(cp_response)); + printk (KERN_DEBUG "vmlogrdr: recording response: %s", + cp_response); + + return count; +} + + +static DEVICE_ATTR(purge, 0200, NULL, vmlogrdr_purge_store); + + +static ssize_t +vmlogrdr_autorecording_store(struct device *dev, const char *buf, + size_t count) { + struct vmlogrdr_priv_t *priv = dev->driver_data; + 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, char *buf) { + struct vmlogrdr_priv_t *priv = dev->driver_data; + 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, const char * buf, size_t count) { + + struct vmlogrdr_priv_t *priv = dev->driver_data; + 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 +vmlogrdr_recording_status_show(struct device_driver *driver, char *buf) { + + char cp_command[] = "QUERY RECORDING "; + int len; + + cpcmd(cp_command, buf, 4096); + len = strlen(buf); + return len; +} + + +static DRIVER_ATTR(recording_status, 0444, vmlogrdr_recording_status_show, + 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 struct class_simple *vmlogrdr_class; +static struct device_driver vmlogrdr_driver = { + .name = "vmlogrdr", + .bus = &iucv_bus, +}; + + +static int +vmlogrdr_register_driver(void) { + int ret; + + ret = driver_register(&vmlogrdr_driver); + if (ret) { + printk(KERN_ERR "vmlogrdr: failed to register driver.\n"); + return ret; + } + + ret = driver_create_file(&vmlogrdr_driver, + &driver_attr_recording_status); + if (ret) { + printk(KERN_ERR "vmlogrdr: failed to add driver attribute.\n"); + goto unregdriver; + } + + vmlogrdr_class = class_simple_create(THIS_MODULE, "vmlogrdr"); + if (IS_ERR(vmlogrdr_class)) { + printk(KERN_ERR "vmlogrdr: failed to create class.\n"); + ret=PTR_ERR(vmlogrdr_class); + vmlogrdr_class=NULL; + goto unregattr; + } + return 0; + +unregattr: + driver_remove_file(&vmlogrdr_driver, &driver_attr_recording_status); +unregdriver: + driver_unregister(&vmlogrdr_driver); + return ret; +} + + +static void +vmlogrdr_unregister_driver(void) { + class_simple_destroy(vmlogrdr_class); + vmlogrdr_class = NULL; + driver_remove_file(&vmlogrdr_driver, &driver_attr_recording_status); + driver_unregister(&vmlogrdr_driver); + return; +} + + +static int +vmlogrdr_register_device(struct vmlogrdr_priv_t *priv) { + struct device *dev; + int ret; + + dev = kmalloc(sizeof(struct device), GFP_KERNEL); + if (dev) { + memset(dev, 0, sizeof(struct device)); + snprintf(dev->bus_id, BUS_ID_SIZE, "%s", + priv->internal_name); + dev->bus = &iucv_bus; + dev->parent = iucv_root; + dev->driver = &vmlogrdr_driver; + /* + * 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) + return ret; + + ret = sysfs_create_group(&dev->kobj, &vmlogrdr_attr_group); + if (ret) { + device_unregister(dev); + return ret; + } + priv->class_device = class_simple_device_add( + vmlogrdr_class, + MKDEV(vmlogrdr_major, priv->minor_num), + dev, + "%s", dev->bus_id ); + if (IS_ERR(priv->class_device)) { + ret = PTR_ERR(priv->class_device); + priv->class_device=NULL; + sysfs_remove_group(&dev->kobj, &vmlogrdr_attr_group); + device_unregister(dev); + return ret; + } + dev->driver_data = priv; + priv->device = dev; + return 0; +} + + +static int +vmlogrdr_unregister_device(struct vmlogrdr_priv_t *priv ) { + class_simple_device_remove(MKDEV(vmlogrdr_major, priv->minor_num)); + if (priv->device != NULL) { + sysfs_remove_group(&priv->device->kobj, &vmlogrdr_attr_group); + 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; + vmlogrdr_cdev->dev = dev; + rc = cdev_add(vmlogrdr_cdev, 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 +vmlogrdr_init(void) +{ + int rc; + int i; + dev_t dev; + + if (! MACHINE_IS_VM) { + printk (KERN_ERR "vmlogrdr: 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); + 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; + printk (KERN_INFO "vmlogrdr: driver loaded\n"); + return 0; + +cleanup: + vmlogrdr_cleanup(); + printk (KERN_ERR "vmlogrdr: driver not loaded.\n"); + return rc; +} + + +static void +vmlogrdr_exit(void) +{ + vmlogrdr_cleanup(); + printk (KERN_INFO "vmlogrdr: driver unloaded\n"); + return; +} + + +module_init(vmlogrdr_init); +module_exit(vmlogrdr_exit); |