From e7549b926dd3ceec048f5689df90d4ec970c9419 Mon Sep 17 00:00:00 2001
From: Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de>
Date: Fri, 23 Oct 2015 13:30:20 +0200
Subject: more driver stuff from 3.2.72

---
 drivers/vhost/vhost.h | 34 +++++++++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

(limited to 'drivers/vhost/vhost.h')

diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 8e03379..a801e28 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -11,7 +11,12 @@
 #include <linux/uio.h>
 #include <linux/virtio_config.h>
 #include <linux/virtio_ring.h>
-#include <asm/atomic.h>
+#include <linux/atomic.h>
+
+/* This is for zerocopy, used buffer len is set to 1 when lower device DMA
+ * done */
+#define VHOST_DMA_DONE_LEN	1
+#define VHOST_DMA_CLEAR_LEN	0
 
 struct vhost_device;
 
@@ -50,6 +55,18 @@ struct vhost_log {
 	u64 len;
 };
 
+struct vhost_virtqueue;
+
+struct vhost_ubuf_ref {
+	struct kref kref;
+	wait_queue_head_t wait;
+	struct vhost_virtqueue *vq;
+};
+
+struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *, bool zcopy);
+void vhost_ubuf_put(struct vhost_ubuf_ref *);
+void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *);
+
 /* The virtqueue structure describes a queue attached to a device. */
 struct vhost_virtqueue {
 	struct vhost_dev *dev;
@@ -114,6 +131,16 @@ struct vhost_virtqueue {
 	/* Log write descriptors */
 	void __user *log_base;
 	struct vhost_log *log;
+	/* vhost zerocopy support fields below: */
+	/* last used idx for outstanding DMA zerocopy buffers */
+	int upend_idx;
+	/* first used idx for DMA done zerocopy buffers */
+	int done_idx;
+	/* an array of userspace buffers info */
+	struct ubuf_info *ubuf_info;
+	/* Reference counting for outstanding ubufs.
+	 * Protected by vq mutex. Writers must also take device mutex. */
+	struct vhost_ubuf_ref *ubufs;
 };
 
 struct vhost_dev {
@@ -147,6 +174,7 @@ int vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *,
 		      struct vhost_log *log, unsigned int *log_num);
 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
 
+int vhost_init_used(struct vhost_virtqueue *);
 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
 		     unsigned count);
@@ -160,6 +188,8 @@ bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
 
 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
 		    unsigned int log_num, u64 len);
+void vhost_zerocopy_callback(void *arg);
+int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq);
 
 #define vq_err(vq, fmt, ...) do {                                  \
 		pr_debug(pr_fmt(fmt), ##__VA_ARGS__);       \
@@ -186,4 +216,6 @@ static inline int vhost_has_feature(struct vhost_dev *dev, int bit)
 	return acked_features & (1 << bit);
 }
 
+void vhost_enable_zcopy(int vq);
+
 #endif
-- 
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