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@@ -0,0 +1,219 @@
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+/*
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+ * Copyright (C) 2004,2005 IBM Corporation
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+ * Interface implementation for communication with the v/VM control program
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+ * Author(s): Christian Borntraeger <cborntra@de.ibm.com>
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+ *
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+ *
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+ * z/VMs CP offers the possibility to issue commands via the diagnose code 8
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+ * this driver implements a character device that issues these commands and
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+ * returns the answer of CP.
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+
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+ * The idea of this driver is based on cpint from Neale Ferguson and #CP in CMS
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+ */
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+
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+#include <linux/fs.h>
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+#include <linux/init.h>
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+#include <linux/kernel.h>
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+#include <linux/miscdevice.h>
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+#include <linux/module.h>
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+#include <asm/cpcmd.h>
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+#include <asm/debug.h>
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+#include <asm/uaccess.h>
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+#include "vmcp.h"
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+
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+MODULE_LICENSE("GPL");
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+MODULE_AUTHOR("Christian Borntraeger <cborntra@de.ibm.com>");
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+MODULE_DESCRIPTION("z/VM CP interface");
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+
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+static debug_info_t *vmcp_debug;
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+
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+static int vmcp_open(struct inode *inode, struct file *file)
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+{
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+ struct vmcp_session *session;
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+
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+ if (!capable(CAP_SYS_ADMIN))
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+ return -EPERM;
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+
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+ session = kmalloc(sizeof(*session), GFP_KERNEL);
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+ if (!session)
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+ return -ENOMEM;
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+ session->bufsize = PAGE_SIZE;
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+ session->response = NULL;
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+ session->resp_size = 0;
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+ init_MUTEX(&session->mutex);
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+ file->private_data = session;
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+ return nonseekable_open(inode, file);
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+}
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+
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+static int vmcp_release(struct inode *inode, struct file *file)
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+{
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+ struct vmcp_session *session;
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+
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+ session = (struct vmcp_session *)file->private_data;
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+ file->private_data = NULL;
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+ free_pages((unsigned long)session->response, get_order(session->bufsize));
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+ kfree(session);
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+ return 0;
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+}
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+
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+static ssize_t
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+vmcp_read(struct file *file, char __user * buff, size_t count, loff_t * ppos)
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+{
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+ size_t tocopy;
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+ struct vmcp_session *session;
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+
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+ session = (struct vmcp_session *)file->private_data;
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+ if (down_interruptible(&session->mutex))
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+ return -ERESTARTSYS;
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+ if (!session->response) {
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+ up(&session->mutex);
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+ return 0;
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+ }
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+ if (*ppos > session->resp_size) {
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+ up(&session->mutex);
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+ return 0;
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+ }
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+ tocopy = min(session->resp_size - (size_t) (*ppos), count);
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+ tocopy = min(tocopy,session->bufsize - (size_t) (*ppos));
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+
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+ if (copy_to_user(buff, session->response + (*ppos), tocopy)) {
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+ up(&session->mutex);
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+ return -EFAULT;
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+ }
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+ up(&session->mutex);
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+ *ppos += tocopy;
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+ return tocopy;
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+}
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+
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+static ssize_t
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+vmcp_write(struct file *file, const char __user * buff, size_t count,
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+ loff_t * ppos)
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+{
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+ char *cmd;
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+ struct vmcp_session *session;
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+
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+ if (count > 240)
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+ return -EINVAL;
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+ cmd = kmalloc(count + 1, GFP_KERNEL);
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+ if (!cmd)
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+ return -ENOMEM;
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+ if (copy_from_user(cmd, buff, count)) {
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+ kfree(cmd);
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+ return -EFAULT;
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+ }
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+ cmd[count] = '\0';
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+ session = (struct vmcp_session *)file->private_data;
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+ if (down_interruptible(&session->mutex))
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+ return -ERESTARTSYS;
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+ if (!session->response)
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+ session->response = (char *)__get_free_pages(GFP_KERNEL
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+ | __GFP_REPEAT | GFP_DMA,
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+ get_order(session->bufsize));
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+ if (!session->response) {
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+ up(&session->mutex);
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+ kfree(cmd);
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+ return -ENOMEM;
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+ }
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+ debug_text_event(vmcp_debug, 1, cmd);
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+ session->resp_size = cpcmd(cmd, session->response,
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+ session->bufsize,
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+ &session->resp_code);
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+ up(&session->mutex);
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+ kfree(cmd);
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+ *ppos = 0; /* reset the file pointer after a command */
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+ return count;
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+}
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+
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+
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+/*
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+ * These ioctls are available, as the semantics of the diagnose 8 call
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+ * does not fit very well into a Linux call. Diagnose X'08' is described in
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+ * CP Programming Services SC24-6084-00
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+ *
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+ * VMCP_GETCODE: gives the CP return code back to user space
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+ * VMCP_SETBUF: sets the response buffer for the next write call. diagnose 8
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+ * expects adjacent pages in real storage and to make matters worse, we
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+ * dont know the size of the response. Therefore we default to PAGESIZE and
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+ * let userspace to change the response size, if userspace expects a bigger
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+ * response
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+ */
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+static long vmcp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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+{
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+ struct vmcp_session *session;
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+ int temp;
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+
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+ session = (struct vmcp_session *)file->private_data;
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+ if (down_interruptible(&session->mutex))
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+ return -ERESTARTSYS;
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+ switch (cmd) {
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+ case VMCP_GETCODE:
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+ temp = session->resp_code;
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+ up(&session->mutex);
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+ return put_user(temp, (int __user *)arg);
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+ case VMCP_SETBUF:
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+ free_pages((unsigned long)session->response,
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+ get_order(session->bufsize));
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+ session->response=NULL;
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+ temp = get_user(session->bufsize, (int __user *)arg);
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+ if (get_order(session->bufsize) > 8) {
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+ session->bufsize = PAGE_SIZE;
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+ temp = -EINVAL;
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+ }
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+ up(&session->mutex);
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+ return temp;
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+ case VMCP_GETSIZE:
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+ temp = session->resp_size;
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+ up(&session->mutex);
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+ return put_user(temp, (int __user *)arg);
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+ default:
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+ up(&session->mutex);
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+ return -ENOIOCTLCMD;
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+ }
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+}
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+
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+static struct file_operations vmcp_fops = {
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+ .owner = THIS_MODULE,
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+ .open = &vmcp_open,
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+ .release = &vmcp_release,
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+ .read = &vmcp_read,
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+ .llseek = &no_llseek,
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+ .write = &vmcp_write,
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+ .unlocked_ioctl = &vmcp_ioctl,
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+ .compat_ioctl = &vmcp_ioctl
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+};
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+
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+static struct miscdevice vmcp_dev = {
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+ .name = "vmcp",
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+ .minor = MISC_DYNAMIC_MINOR,
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+ .fops = &vmcp_fops,
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+};
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+
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+static int __init vmcp_init(void)
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+{
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+ int ret;
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+
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+ if (!MACHINE_IS_VM) {
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+ printk(KERN_WARNING
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+ "z/VM CP interface is only available under z/VM\n");
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+ return -ENODEV;
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+ }
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+ ret = misc_register(&vmcp_dev);
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+ if (!ret)
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+ printk(KERN_INFO "z/VM CP interface loaded\n");
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+ else
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+ printk(KERN_WARNING
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+ "z/VM CP interface not loaded. Could not register misc device.\n");
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+ vmcp_debug = debug_register("vmcp", 0, 1, 240);
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+ debug_register_view(vmcp_debug, &debug_hex_ascii_view);
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+ return ret;
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+}
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+
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+static void __exit vmcp_exit(void)
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+{
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+ WARN_ON(misc_deregister(&vmcp_dev) != 0);
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+ debug_unregister(vmcp_debug);
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+ printk(KERN_INFO "z/VM CP interface unloaded.\n");
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+}
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+
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+module_init(vmcp_init);
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+module_exit(vmcp_exit);
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Christian Borntraeger