#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/mod_devicetable.h>
+#include <linux/gfp.h>
/**
* virtqueue - a queue to register buffers for sending or receiving.
+ * @list: the chain of virtqueues for this device
* @callback: the function to call when buffers are consumed (can be NULL).
+ * @name: the name of this virtqueue (mainly for debugging)
* @vdev: the virtio device this queue was created for.
- * @vq_ops: the operations for this virtqueue (see below).
* @priv: a pointer for the virtqueue implementation to use.
*/
-struct virtqueue
-{
+struct virtqueue {
+ struct list_head list;
void (*callback)(struct virtqueue *vq);
+ const char *name;
struct virtio_device *vdev;
- struct virtqueue_ops *vq_ops;
void *priv;
};
/**
- * virtqueue_ops - operations for virtqueue abstraction layer
- * @add_buf: expose buffer to other end
+ * operations for virtqueue
+ * virtqueue_add_buf: expose buffer to other end
* vq: the struct virtqueue we're talking about.
* sg: the description of the buffer(s).
* out_num: the number of sg readable by other side
* in_num: the number of sg which are writable (after readable ones)
* data: the token identifying the buffer.
- * Returns 0 or an error.
- * @kick: update after add_buf
+ * gfp: how to do memory allocations (if necessary).
+ * Returns remaining capacity of queue (sg segments) or a negative error.
+ * virtqueue_kick: update after add_buf
* vq: the struct virtqueue
* After one or more add_buf calls, invoke this to kick the other side.
- * @get_buf: get the next used buffer
+ * virtqueue_get_buf: get the next used buffer
* vq: the struct virtqueue we're talking about.
* len: the length written into the buffer
* Returns NULL or the "data" token handed to add_buf.
- * @disable_cb: disable callbacks
+ * virtqueue_disable_cb: disable callbacks
* vq: the struct virtqueue we're talking about.
* Note that this is not necessarily synchronous, hence unreliable and only
* useful as an optimization.
- * @enable_cb: restart callbacks after disable_cb.
+ * virtqueue_enable_cb: restart callbacks after disable_cb.
* vq: the struct virtqueue we're talking about.
* This re-enables callbacks; it returns "false" if there are pending
* buffers in the queue, to detect a possible race between the driver
* checking for more work, and enabling callbacks.
+ * virtqueue_detach_unused_buf: detach first unused buffer
+ * vq: the struct virtqueue we're talking about.
+ * Returns NULL or the "data" token handed to add_buf
*
* Locking rules are straightforward: the driver is responsible for
* locking. No two operations may be invoked simultaneously, with the exception
- * of @disable_cb.
+ * of virtqueue_disable_cb.
*
* All operations can be called in any context.
*/
-struct virtqueue_ops {
- int (*add_buf)(struct virtqueue *vq,
- struct scatterlist sg[],
- unsigned int out_num,
- unsigned int in_num,
- void *data);
- void (*kick)(struct virtqueue *vq);
+int virtqueue_add_buf_gfp(struct virtqueue *vq,
+ struct scatterlist sg[],
+ unsigned int out_num,
+ unsigned int in_num,
+ void *data,
+ gfp_t gfp);
+
+static inline int virtqueue_add_buf(struct virtqueue *vq,
+ struct scatterlist sg[],
+ unsigned int out_num,
+ unsigned int in_num,
+ void *data)
+{
+ return virtqueue_add_buf_gfp(vq, sg, out_num, in_num, data, GFP_ATOMIC);
+}
- void *(*get_buf)(struct virtqueue *vq, unsigned int *len);
+void virtqueue_kick(struct virtqueue *vq);
- void (*disable_cb)(struct virtqueue *vq);
- bool (*enable_cb)(struct virtqueue *vq);
-};
+void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
+
+void virtqueue_disable_cb(struct virtqueue *vq);
+
+bool virtqueue_enable_cb(struct virtqueue *vq);
+
+void *virtqueue_detach_unused_buf(struct virtqueue *vq);
/**
* virtio_device - representation of a device using virtio
* @dev: underlying device.
* @id: the device type identification (used to match it with a driver).
* @config: the configuration ops for this device.
+ * @vqs: the list of virtqueues for this device.
* @features: the features supported by both driver and device.
* @priv: private pointer for the driver's use.
*/
-struct virtio_device
-{
+struct virtio_device {
int index;
struct device dev;
struct virtio_device_id id;
struct virtio_config_ops *config;
+ struct list_head vqs;
/* Note that this is a Linux set_bit-style bitmap. */
unsigned long features[1];
void *priv;
};
+#define dev_to_virtio(dev) container_of(dev, struct virtio_device, dev)
int register_virtio_device(struct virtio_device *dev);
void unregister_virtio_device(struct virtio_device *dev);
* @id_table: the ids serviced by this driver.
* @feature_table: an array of feature numbers supported by this device.
* @feature_table_size: number of entries in the feature table array.
- * @probe: the function to call when a device is found. Returns a token for
- * remove, or PTR_ERR().
+ * @probe: the function to call when a device is found. Returns 0 or -errno.
* @remove: the function when a device is removed.
* @config_changed: optional function to call when the device configuration
* changes; may be called in interrupt context.
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff