[PATCH 2/6] xen: Add xenbus device driver

From: Bastian Blank
Date: Sat Dec 10 2011 - 13:31:04 EST


Access to xenbus is currently handled via xenfs. This adds a device
driver for xenbus and makes xenfs use this code.

Signed-off-by: Bastian Blank <waldi@xxxxxxxxxx>
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
drivers/xen/xenbus/Makefile | 1 +
drivers/xen/xenbus/xenbus_comms.h | 4 ++
.../xenbus.c => xenbus/xenbus_dev_frontend.c} | 37 ++++++++++++++++++--
drivers/xen/xenfs/Makefile | 2 +-
drivers/xen/xenfs/super.c | 3 +-
drivers/xen/xenfs/xenfs.h | 1 -
6 files changed, 42 insertions(+), 6 deletions(-)
rename drivers/xen/{xenfs/xenbus.c => xenbus/xenbus_dev_frontend.c} (95%)

diff --git a/drivers/xen/xenbus/Makefile b/drivers/xen/xenbus/Makefile
index 8dca685..a2ea363 100644
--- a/drivers/xen/xenbus/Makefile
+++ b/drivers/xen/xenbus/Makefile
@@ -1,4 +1,5 @@
obj-y += xenbus.o
+obj-y += xenbus_dev_frontend.o

xenbus-objs =
xenbus-objs += xenbus_client.o
diff --git a/drivers/xen/xenbus/xenbus_comms.h b/drivers/xen/xenbus/xenbus_comms.h
index c21db75..6e42800 100644
--- a/drivers/xen/xenbus/xenbus_comms.h
+++ b/drivers/xen/xenbus/xenbus_comms.h
@@ -31,6 +31,8 @@
#ifndef _XENBUS_COMMS_H
#define _XENBUS_COMMS_H

+#include <linux/fs.h>
+
int xs_init(void);
int xb_init_comms(void);

@@ -43,4 +45,6 @@ int xs_input_avail(void);
extern struct xenstore_domain_interface *xen_store_interface;
extern int xen_store_evtchn;

+extern const struct file_operations xen_xenbus_fops;
+
#endif /* _XENBUS_COMMS_H */
diff --git a/drivers/xen/xenfs/xenbus.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
similarity index 95%
rename from drivers/xen/xenfs/xenbus.c
rename to drivers/xen/xenbus/xenbus_dev_frontend.c
index bbd000f..fb30cff 100644
--- a/drivers/xen/xenfs/xenbus.c
+++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -52,13 +52,16 @@
#include <linux/namei.h>
#include <linux/string.h>
#include <linux/slab.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>

-#include "xenfs.h"
-#include "../xenbus/xenbus_comms.h"
+#include "xenbus_comms.h"

#include <xen/xenbus.h>
#include <asm/xen/hypervisor.h>

+MODULE_LICENSE("GPL");
+
/*
* An element of a list of outstanding transactions, for which we're
* still waiting a reply.
@@ -583,7 +586,7 @@ static unsigned int xenbus_file_poll(struct file *file, poll_table *wait)
return 0;
}

-const struct file_operations xenbus_file_ops = {
+const struct file_operations xen_xenbus_fops = {
.read = xenbus_file_read,
.write = xenbus_file_write,
.open = xenbus_file_open,
@@ -591,3 +594,31 @@ const struct file_operations xenbus_file_ops = {
.poll = xenbus_file_poll,
.llseek = no_llseek,
};
+EXPORT_SYMBOL_GPL(xen_xenbus_fops);
+
+static struct miscdevice xenbus_dev = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "xen/xenbus",
+ .fops = &xen_xenbus_fops,
+};
+
+static int __init xenbus_init(void)
+{
+ int err;
+
+ if (!xen_domain())
+ return -ENODEV;
+
+ err = misc_register(&xenbus_dev);
+ if (err)
+ printk(KERN_ERR "Could not register xenbus device\n");
+ return err;
+}
+
+static void __exit xenbus_exit(void)
+{
+ misc_deregister(&xenbus_dev);
+}
+
+module_init(xenbus_init);
+module_exit(xenbus_exit);
diff --git a/drivers/xen/xenfs/Makefile b/drivers/xen/xenfs/Makefile
index 5d45ff1..b019865 100644
--- a/drivers/xen/xenfs/Makefile
+++ b/drivers/xen/xenfs/Makefile
@@ -1,4 +1,4 @@
obj-$(CONFIG_XENFS) += xenfs.o

-xenfs-y = super.o xenbus.o
+xenfs-y = super.o
xenfs-$(CONFIG_XEN_DOM0) += xenstored.o
diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c
index a55fbf9..a84b53c 100644
--- a/drivers/xen/xenfs/super.c
+++ b/drivers/xen/xenfs/super.c
@@ -17,6 +17,7 @@

#include "xenfs.h"
#include "../privcmd.h"
+#include "../xenbus/xenbus_comms.h"

#include <asm/xen/hypervisor.h>

@@ -83,7 +84,7 @@ static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
{
static struct tree_descr xenfs_files[] = {
[1] = {},
- { "xenbus", &xenbus_file_ops, S_IRUSR|S_IWUSR },
+ { "xenbus", &xen_xenbus_fops, S_IRUSR|S_IWUSR },
{ "capabilities", &capabilities_file_ops, S_IRUGO },
{ "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },
{""},
diff --git a/drivers/xen/xenfs/xenfs.h b/drivers/xen/xenfs/xenfs.h
index 5056306..6b80c77 100644
--- a/drivers/xen/xenfs/xenfs.h
+++ b/drivers/xen/xenfs/xenfs.h
@@ -1,7 +1,6 @@
#ifndef _XENFS_XENBUS_H
#define _XENFS_XENBUS_H

-extern const struct file_operations xenbus_file_ops;
extern const struct file_operations xsd_kva_file_ops;
extern const struct file_operations xsd_port_file_ops;

--
1.7.7.3

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