Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / s390 / char / sclp_ctl.c

diff --git a/kernel/drivers/s390/char/sclp_ctl.c b/kernel/drivers/s390/char/sclp_ctl.c
new file mode 100644 (file)
index 0000000..648cb86
--- /dev/null
+++ b/kernel/drivers/s390/char/sclp_ctl.c
@@ -0,0 +1,144 @@
+/*
+ * IOCTL interface for SCLP
+ *
+ * Copyright IBM Corp. 2012
+ *
+ * Author: Michael Holzheu <holzheu@linux.vnet.ibm.com>
+ */
+
+#include <linux/compat.h>
+#include <linux/uaccess.h>
+#include <linux/miscdevice.h>
+#include <linux/gfp.h>
+#include <linux/module.h>
+#include <linux/ioctl.h>
+#include <linux/fs.h>
+#include <asm/compat.h>
+#include <asm/sclp_ctl.h>
+#include <asm/sclp.h>
+
+#include "sclp.h"
+
+/*
+ * Supported command words
+ */
+static unsigned int sclp_ctl_sccb_wlist[] = {
+       0x00400002,
+       0x00410002,
+};
+
+/*
+ * Check if command word is supported
+ */
+static int sclp_ctl_cmdw_supported(unsigned int cmdw)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(sclp_ctl_sccb_wlist); i++) {
+               if (cmdw == sclp_ctl_sccb_wlist[i])
+                       return 1;
+       }
+       return 0;
+}
+
+static void __user *u64_to_uptr(u64 value)
+{
+       if (is_compat_task())
+               return compat_ptr(value);
+       else
+               return (void __user *)(unsigned long)value;
+}
+
+/*
+ * Start SCLP request
+ */
+static int sclp_ctl_ioctl_sccb(void __user *user_area)
+{
+       struct sclp_ctl_sccb ctl_sccb;
+       struct sccb_header *sccb;
+       int rc;
+
+       if (copy_from_user(&ctl_sccb, user_area, sizeof(ctl_sccb)))
+               return -EFAULT;
+       if (!sclp_ctl_cmdw_supported(ctl_sccb.cmdw))
+               return -EOPNOTSUPP;
+       sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
+       if (!sccb)
+               return -ENOMEM;
+       if (copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), sizeof(*sccb))) {
+               rc = -EFAULT;
+               goto out_free;
+       }
+       if (sccb->length > PAGE_SIZE || sccb->length < 8)
+               return -EINVAL;
+       if (copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), sccb->length)) {
+               rc = -EFAULT;
+               goto out_free;
+       }
+       rc = sclp_sync_request(ctl_sccb.cmdw, sccb);
+       if (rc)
+               goto out_free;
+       if (copy_to_user(u64_to_uptr(ctl_sccb.sccb), sccb, sccb->length))
+               rc = -EFAULT;
+out_free:
+       free_page((unsigned long) sccb);
+       return rc;
+}
+
+/*
+ * SCLP SCCB ioctl function
+ */
+static long sclp_ctl_ioctl(struct file *filp, unsigned int cmd,
+                          unsigned long arg)
+{
+       void __user *argp;
+
+       if (is_compat_task())
+               argp = compat_ptr(arg);
+       else
+               argp = (void __user *) arg;
+       switch (cmd) {
+       case SCLP_CTL_SCCB:
+               return sclp_ctl_ioctl_sccb(argp);
+       default: /* unknown ioctl number */
+               return -ENOTTY;
+       }
+}
+
+/*
+ * File operations
+ */
+static const struct file_operations sclp_ctl_fops = {
+       .owner = THIS_MODULE,
+       .open = nonseekable_open,
+       .unlocked_ioctl = sclp_ctl_ioctl,
+       .compat_ioctl = sclp_ctl_ioctl,
+       .llseek = no_llseek,
+};
+
+/*
+ * Misc device definition
+ */
+static struct miscdevice sclp_ctl_device = {
+       .minor = MISC_DYNAMIC_MINOR,
+       .name = "sclp",
+       .fops = &sclp_ctl_fops,
+};
+
+/*
+ * Register sclp_ctl misc device
+ */
+static int __init sclp_ctl_init(void)
+{
+       return misc_register(&sclp_ctl_device);
+}
+module_init(sclp_ctl_init);
+
+/*
+ * Deregister sclp_ctl misc device
+ */
+static void __exit sclp_ctl_exit(void)
+{
+       misc_deregister(&sclp_ctl_device);
+}
+module_exit(sclp_ctl_exit);