1 files changed, 138 insertions, 84 deletions

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 69d7ea02cd4..fed0ce198ae 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -1,48 +1,79 @@
 #include <linux/virtio.h>
 #include <linux/spinlock.h>
 #include <linux/virtio_config.h>
+#include <linux/module.h>
+#include <linux/idr.h>
+
+/* Unique numbering for virtio devices. */
+static DEFINE_IDA(virtio_index_ida);
 
 static ssize_t device_show(struct device *_d,
 			   struct device_attribute *attr, char *buf)
 {
-	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
-	return sprintf(buf, "%hu", dev->id.device);
+	struct virtio_device *dev = dev_to_virtio(_d);
+	return sprintf(buf, "0x%04x\n", dev->id.device);
 }
+static DEVICE_ATTR_RO(device);
+
 static ssize_t vendor_show(struct device *_d,
 			   struct device_attribute *attr, char *buf)
 {
-	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
-	return sprintf(buf, "%hu", dev->id.vendor);
+	struct virtio_device *dev = dev_to_virtio(_d);
+	return sprintf(buf, "0x%04x\n", dev->id.vendor);
 }
+static DEVICE_ATTR_RO(vendor);
+
 static ssize_t status_show(struct device *_d,
 			   struct device_attribute *attr, char *buf)
 {
-	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
-	return sprintf(buf, "0x%08x", dev->config->get_status(dev));
+	struct virtio_device *dev = dev_to_virtio(_d);
+	return sprintf(buf, "0x%08x\n", dev->config->get_status(dev));
 }
+static DEVICE_ATTR_RO(status);
+
 static ssize_t modalias_show(struct device *_d,
 			     struct device_attribute *attr, char *buf)
 {
-	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
-
+	struct virtio_device *dev = dev_to_virtio(_d);
 	return sprintf(buf, "virtio:d%08Xv%08X\n",
 		       dev->id.device, dev->id.vendor);
 }
-static struct device_attribute virtio_dev_attrs[] = {
-	__ATTR_RO(device),
-	__ATTR_RO(vendor),
-	__ATTR_RO(status),
-	__ATTR_RO(modalias),
-	__ATTR_NULL
+static DEVICE_ATTR_RO(modalias);
+
+static ssize_t features_show(struct device *_d,
+			     struct device_attribute *attr, char *buf)
+{
+	struct virtio_device *dev = dev_to_virtio(_d);
+	unsigned int i;
+	ssize_t len = 0;
+
+	/* We actually represent this as a bitstring, as it could be
+	 * arbitrary length in future. */
+	for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++)
+		len += sprintf(buf+len, "%c",
+			       test_bit(i, dev->features) ? '1' : '0');
+	len += sprintf(buf+len, "\n");
+	return len;
+}
+static DEVICE_ATTR_RO(features);
+
+static struct attribute *virtio_dev_attrs[] = {
+	&dev_attr_device.attr,
+	&dev_attr_vendor.attr,
+	&dev_attr_status.attr,
+	&dev_attr_modalias.attr,
+	&dev_attr_features.attr,
+	NULL,
 };
+ATTRIBUTE_GROUPS(virtio_dev);
 
 static inline int virtio_id_match(const struct virtio_device *dev,
 				  const struct virtio_device_id *id)
 {
-	if (id->device != dev->id.device)
+	if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID)
 		return 0;
 
-	return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor != dev->id.vendor;
+	return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor;
 }
 
 /* This looks through all the IDs a driver claims to support.  If any of them
@@ -50,10 +81,10 @@ static inline int virtio_id_match(const struct virtio_device *dev,
 static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
 {
 	unsigned int i;
-	struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
+	struct virtio_device *dev = dev_to_virtio(_dv);
 	const struct virtio_device_id *ids;
 
-	ids = container_of(_dr, struct virtio_driver, driver)->id_table;
+	ids = drv_to_virtio(_dr)->id_table;
 	for (i = 0; ids[i].device; i++)
 		if (virtio_id_match(dev, &ids[i]))
 			return 1;
@@ -62,57 +93,100 @@ static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
 
 static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
 {
-	struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
+	struct virtio_device *dev = dev_to_virtio(_dv);
 
 	return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
 			      dev->id.device, dev->id.vendor);
 }
 
-static struct bus_type virtio_bus = {
-	.name  = "virtio",
-	.match = virtio_dev_match,
-	.dev_attrs = virtio_dev_attrs,
-	.uevent = virtio_uevent,
-};
-
 static void add_status(struct virtio_device *dev, unsigned status)
 {
 	dev->config->set_status(dev, dev->config->get_status(dev) | status);
 }
 
+void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
+					 unsigned int fbit)
+{
+	unsigned int i;
+	struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver);
+
+	for (i = 0; i < drv->feature_table_size; i++)
+		if (drv->feature_table[i] == fbit)
+			return;
+	BUG();
+}
+EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
+
 static int virtio_dev_probe(struct device *_d)
 {
-	int err;
-	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
-	struct virtio_driver *drv = container_of(dev->dev.driver,
-						 struct virtio_driver, driver);
+	int err, i;
+	struct virtio_device *dev = dev_to_virtio(_d);
+	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
+	u32 device_features;
 
+	/* We have a driver! */
 	add_status(dev, VIRTIO_CONFIG_S_DRIVER);
+
+	/* Figure out what features the device supports. */
+	device_features = dev->config->get_features(dev);
+
+	/* Features supported by both device and driver into dev->features. */
+	memset(dev->features, 0, sizeof(dev->features));
+	for (i = 0; i < drv->feature_table_size; i++) {
+		unsigned int f = drv->feature_table[i];
+		BUG_ON(f >= 32);
+		if (device_features & (1 << f))
+			set_bit(f, dev->features);
+	}
+
+	/* Transport features always preserved to pass to finalize_features. */
+	for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
+		if (device_features & (1 << i))
+			set_bit(i, dev->features);
+
+	dev->config->finalize_features(dev);
+
 	err = drv->probe(dev);
 	if (err)
 		add_status(dev, VIRTIO_CONFIG_S_FAILED);
-	else
+	else {
 		add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
+		if (drv->scan)
+			drv->scan(dev);
+	}
+
 	return err;
 }
 
 static int virtio_dev_remove(struct device *_d)
 {
-	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
-	struct virtio_driver *drv = container_of(dev->dev.driver,
-						 struct virtio_driver, driver);
+	struct virtio_device *dev = dev_to_virtio(_d);
+	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
 
-	dev->config->set_status(dev, dev->config->get_status(dev)
-				& ~VIRTIO_CONFIG_S_DRIVER);
 	drv->remove(dev);
+
+	/* Driver should have reset device. */
+	WARN_ON_ONCE(dev->config->get_status(dev));
+
+	/* Acknowledge the device's existence again. */
+	add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
 	return 0;
 }
 
+static struct bus_type virtio_bus = {
+	.name  = "virtio",
+	.match = virtio_dev_match,
+	.dev_groups = virtio_dev_groups,
+	.uevent = virtio_uevent,
+	.probe = virtio_dev_probe,
+	.remove = virtio_dev_remove,
+};
+
 int register_virtio_driver(struct virtio_driver *driver)
 {
+	/* Catch this early. */
+	BUG_ON(driver->feature_table_size && !driver->feature_table);
 	driver->driver.bus = &virtio_bus;
-	driver->driver.probe = virtio_dev_probe;
-	driver->driver.remove = virtio_dev_remove;
 	return driver_register(&driver->driver);
 }
 EXPORT_SYMBOL_GPL(register_virtio_driver);
@@ -128,14 +202,28 @@ int register_virtio_device(struct virtio_device *dev)
 	int err;
 
 	dev->dev.bus = &virtio_bus;
-	sprintf(dev->dev.bus_id, "%u", dev->index);
+
+	/* Assign a unique device index and hence name. */
+	err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL);
+	if (err < 0)
+		goto out;
+
+	dev->index = err;
+	dev_set_name(&dev->dev, "virtio%u", dev->index);
+
+	/* We always start by resetting the device, in case a previous
+	 * driver messed it up.  This also tests that code path a little. */
+	dev->config->reset(dev);
 
 	/* Acknowledge that we've seen the device. */
 	add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
 
+	INIT_LIST_HEAD(&dev->vqs);
+
 	/* device_register() causes the bus infrastructure to look for a
 	 * matching driver. */
 	err = device_register(&dev->dev);
+out:
 	if (err)
 		add_status(dev, VIRTIO_CONFIG_S_FAILED);
 	return err;
@@ -144,59 +232,25 @@ EXPORT_SYMBOL_GPL(register_virtio_device);
 
 void unregister_virtio_device(struct virtio_device *dev)
 {
+	int index = dev->index; /* save for after device release */
+
 	device_unregister(&dev->dev);
+	ida_simple_remove(&virtio_index_ida, index);
 }
 EXPORT_SYMBOL_GPL(unregister_virtio_device);
 
-int __virtio_config_val(struct virtio_device *vdev,
-			u8 type, void *val, size_t size)
-{
-	void *token;
-	unsigned int len;
-
-	token = vdev->config->find(vdev, type, &len);
-	if (!token)
-		return -ENOENT;
-
-	if (len != size)
-		return -EIO;
-
-	vdev->config->get(vdev, token, val, size);
-	return 0;
-}
-EXPORT_SYMBOL_GPL(__virtio_config_val);
-
-int virtio_use_bit(struct virtio_device *vdev,
-		   void *token, unsigned int len, unsigned int bitnum)
-{
-	unsigned long bits[16];
-
-	/* This makes it convenient to pass-through find() results. */
-	if (!token)
-		return 0;
-
-	/* bit not in range of this bitfield? */
-	if (bitnum * 8 >= len / 2)
-		return 0;
-
-	/* Giant feature bitfields are silly. */
-	BUG_ON(len > sizeof(bits));
-	vdev->config->get(vdev, token, bits, len);
-
-	if (!test_bit(bitnum, bits))
-		return 0;
-
-	/* Set acknowledge bit, and write it back. */
-	set_bit(bitnum + len * 8 / 2, bits);
-	vdev->config->set(vdev, token, bits, len);
-	return 1;
-}
-EXPORT_SYMBOL_GPL(virtio_use_bit);
-
 static int virtio_init(void)
 {
 	if (bus_register(&virtio_bus) != 0)
 		panic("virtio bus registration failed");
 	return 0;
 }
+
+static void __exit virtio_exit(void)
+{
+	bus_unregister(&virtio_bus);
+}
 core_initcall(virtio_init);
+module_exit(virtio_exit);
+
+MODULE_LICENSE("GPL");