1 files changed, 129 insertions, 0 deletions
diff --git a/drivers/s390/char/sclp_ctl.c b/drivers/s390/char/sclp_ctl.c
new file mode 100644
index 000000000..248b5db3e
--- /dev/null
+++ b/drivers/s390/char/sclp_ctl.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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/init.h>
+#include <linux/ioctl.h>
+#include <linux/fs.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;
+	unsigned long copied;
+	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;
+	copied = PAGE_SIZE -
+		copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), PAGE_SIZE);
+	if (offsetof(struct sccb_header, length) +
+	    sizeof(sccb->length) > copied || sccb->length > copied) {
+		rc = -EFAULT;
+		goto out_free;
+	}
+	if (sccb->length < 8) {
+		rc = -EINVAL;
+		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,
+};
+builtin_misc_device(sclp_ctl_device);