staging: visorchipset driver to provide registration and other services

The visorchipset module receives device creation and destruction
events from the Command service partition of s-Par, as well as
controlling registration of shared device drivers with the s-Par
driver core. The events received are used to populate other s-Par
modules with their assigned shared devices. Visorchipset is required
for shared device drivers to function properly. Visorchipset also
stores information for handling dump disk device creation during
kdump.

In operation, the visorchipset module processes device creation and
destruction messages sent by s-Par's Command service partition through
a channel. These messages result in creation (or destruction) of each
virtual bus and virtual device. Each bus and device is also associated
with a communication channel, which is used to communicate with one or
more IO service partitions to perform device IO on behalf of the
guest.

Signed-off-by: Ken Cox <jkc@redhat.com>
Cc: Ben Romer <sparmaintainer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 223 insertions, 0 deletions

diff --git a/drivers/staging/unisys/visorchipset/file.c b/drivers/staging/unisys/visorchipset/file.c
new file mode 100644
index 000000000000..b0d28a2b5231
--- /dev/null
+++ b/drivers/staging/unisys/visorchipset/file.c
@@ -0,0 +1,223 @@
+/* file.c
+ *
+ * Copyright © 2010 - 2013 UNISYS CORPORATION
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ */
+
+/* This contains the implementation that allows a usermode program to
+ * communicate with the visorchipset driver using a device/file interface.
+ */
+
+#include "globals.h"
+#include "visorchannel.h"
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include "uisutils.h"
+
+#define CURRENT_FILE_PC VISOR_CHIPSET_PC_file_c
+
+static struct cdev Cdev;
+static VISORCHANNEL **PControlVm_channel;
+static dev_t MajorDev = -1; /**< indicates major num for device */
+static BOOL Registered = FALSE;
+
+static int visorchipset_open(struct inode *inode, struct file *file);
+static int visorchipset_release(struct inode *inode, struct file *file);
+static int visorchipset_mmap(struct file *file, struct vm_area_struct *vma);
+#ifdef HAVE_UNLOCKED_IOCTL
+long visorchipset_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+#else
+int visorchipset_ioctl(struct inode *inode, struct file *file,
+		       unsigned int cmd, unsigned long arg);
+#endif
+
+static const struct file_operations visorchipset_fops = {
+	.owner = THIS_MODULE,
+	.open = visorchipset_open,
+	.read = NULL,
+	.write = NULL,
+#ifdef HAVE_UNLOCKED_IOCTL
+	.unlocked_ioctl = visorchipset_ioctl,
+#else
+	.ioctl = visorchipset_ioctl,
+#endif
+	.release = visorchipset_release,
+	.mmap = visorchipset_mmap,
+};
+
+int
+visorchipset_file_init(dev_t majorDev, VISORCHANNEL **pControlVm_channel)
+{
+	int rc = -1;
+
+	PControlVm_channel = pControlVm_channel;
+	MajorDev = majorDev;
+	cdev_init(&Cdev, &visorchipset_fops);
+	Cdev.owner = THIS_MODULE;
+	if (MAJOR(MajorDev) == 0) {
+		/* dynamic major device number registration required */
+		if (alloc_chrdev_region(&MajorDev, 0, 1, MYDRVNAME) < 0) {
+			ERRDRV("Unable to allocate+register char device %s",
+			       MYDRVNAME);
+			RETINT(-1);
+		}
+		Registered = TRUE;
+		INFODRV("New major number %d registered\n", MAJOR(MajorDev));
+	} else {
+		/* static major device number registration required */
+		if (register_chrdev_region(MajorDev, 1, MYDRVNAME) < 0) {
+			ERRDRV("Unable to register char device %s", MYDRVNAME);
+			RETINT(-1);
+		}
+		Registered = TRUE;
+		INFODRV("Static major number %d registered\n", MAJOR(MajorDev));
+	}
+	if (cdev_add(&Cdev, MKDEV(MAJOR(MajorDev), 0), 1) < 0)
+		FAIL("failed to create char device", -1);
+	INFODRV("Registered char device for %s (major=%d)",
+		MYDRVNAME, MAJOR(MajorDev));
+	RETINT(0);
+Away:
+	return rc;
+}
+
+void
+visorchipset_file_cleanup(void)
+{
+	if (Cdev.ops != NULL)
+		cdev_del(&Cdev);
+	Cdev.ops = NULL;
+	if (Registered) {
+		if (MAJOR(MajorDev) >= 0) {
+			unregister_chrdev_region(MajorDev, 1);
+			MajorDev = MKDEV(0, 0);
+		}
+		Registered = FALSE;
+	}
+}
+
+static int
+visorchipset_open(struct inode *inode, struct file *file)
+{
+	unsigned minor_number = iminor(inode);
+	int rc = -ENODEV;
+
+	DEBUGDRV("%s", __func__);
+	if (minor_number != 0)
+		RETINT(-ENODEV);
+	file->private_data = NULL;
+	RETINT(0);
+Away:
+	if (rc < 0)
+		ERRDRV("%s minor=%d failed", __func__, minor_number);
+	return rc;
+}
+
+static int
+visorchipset_release(struct inode *inode, struct file *file)
+{
+	int rc = -1;
+	DEBUGDRV("%s", __func__);
+	RETINT(0);
+Away:
+	return rc;
+}
+
+static int
+visorchipset_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	ulong physAddr = 0;
+	ulong offset = vma->vm_pgoff << PAGE_SHIFT;
+	GUEST_PHYSICAL_ADDRESS addr = 0;
+
+	/* sv_enable_dfp(); */
+	DEBUGDRV("%s", __func__);
+	if (offset & (PAGE_SIZE - 1)) {
+		ERRDRV("%s virtual address NOT page-aligned!", __func__);
+		return -ENXIO;	/* need aligned offsets */
+	}
+	switch (offset) {
+	case VISORCHIPSET_MMAP_CONTROLCHANOFFSET:
+		vma->vm_flags |= VM_IO;
+		if (*PControlVm_channel == NULL) {
+			ERRDRV("%s no controlvm channel yet", __func__);
+			return -ENXIO;
+		}
+		visorchannel_read(*PControlVm_channel,
+				  offsetof(ULTRA_CONTROLVM_CHANNEL_PROTOCOL,
+					   gpControlChannel), &addr,
+				  sizeof(addr));
+		if (addr == 0) {
+			ERRDRV("%s control channel address is 0", __func__);
+			return -ENXIO;
+		}
+		physAddr = (ulong) (addr);
+		DEBUGDRV("mapping physical address = 0x%lx", physAddr);
+		if (remap_pfn_range(vma, vma->vm_start,
+				    physAddr >> PAGE_SHIFT,
+				    vma->vm_end - vma->vm_start,
+				    /*pgprot_noncached */
+				    (vma->vm_page_prot))) {
+			ERRDRV("%s remap_pfn_range failed", __func__);
+			return -EAGAIN;
+		}
+		break;
+	default:
+		return -ENOSYS;
+	}
+	DEBUGDRV("%s success!", __func__);
+	return 0;
+}
+
+#ifdef HAVE_UNLOCKED_IOCTL
+long
+visorchipset_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+#else
+int
+visorchipset_ioctl(struct inode *inode, struct file *file,
+		   unsigned int cmd, unsigned long arg)
+#endif
+{
+	int rc = SUCCESS;
+	S64 adjustment;
+	S64 vrtc_offset;
+	DBGINF("entered visorchipset_ioctl, cmd=%d", cmd);
+	switch (cmd) {
+	case VMCALL_QUERY_GUEST_VIRTUAL_TIME_OFFSET:
+		/* get the physical rtc offset */
+		vrtc_offset = Issue_VMCALL_QUERY_GUEST_VIRTUAL_TIME_OFFSET();
+		if (copy_to_user
+		    ((void __user *)arg, &vrtc_offset, sizeof(vrtc_offset)))
+			RETINT(-EFAULT);
+		DBGINF("insde visorchipset_ioctl, cmd=%d, vrtc_offset=%lld",
+		       cmd, vrtc_offset);
+		break;
+	case VMCALL_UPDATE_PHYSICAL_TIME:
+		if (copy_from_user
+		    (&adjustment, (void __user *)arg, sizeof(adjustment)))
+			RETINT(-EFAULT);
+		DBGINF("insde visorchipset_ioctl, cmd=%d, adjustment=%lld", cmd,
+		       adjustment);
+		rc = Issue_VMCALL_UPDATE_PHYSICAL_TIME(adjustment);
+		break;
+	default:
+		LOGERR("visorchipset_ioctl received invalid command");
+		RETINT(-EFAULT);
+		break;
+	}
+	RETINT(rc);
+Away:
+	DBGINF("exiting %d!", rc);
+	return rc;
+}