Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
tools/virtio/linux/virtio.h | 45 ++++++++++++++++++++++++++++++++++++++-------
1 file changed, 38 insertions(+), 7 deletions(-)
diff --git a/tools/virtio/linux/virtio.h b/tools/virtio/linux/virtio.h
index 390c4cb..0426a75 100644
--- a/tools/virtio/linux/virtio.h
+++ b/tools/virtio/linux/virtio.h
@@ -11,6 +11,13 @@
#include <linux/types.h>
#include <errno.h>
+# ifndef likely
+# define likely(x) (__builtin_expect(!!(x), 1))
+# endif
+# ifndef unlikely
+# define unlikely(x) (__builtin_expect(!!(x), 0))
+# endif
+
typedef unsigned long long dma_addr_t;
struct scatterlist {
@@ -43,6 +50,10 @@ static inline void sg_mark_end(struct scatterlist *sg)
sg->page_link |= 0x02;
sg->page_link &= ~0x01;
}
+static inline void sg_unmark_end(struct scatterlist *sg)
+{
+ sg->page_link &= ~0x02;
+}
static inline void sg_init_table(struct scatterlist *sgl, unsigned int nents)
{
memset(sgl, 0, sizeof(*sgl) * nents);
@@ -79,6 +90,26 @@ static inline void sg_init_one(struct scatterlist *sg, const void *buf, unsigned
sg_init_table(sg, 1);
sg_set_buf(sg, buf, buflen);
}
+/*
+ * We overload the LSB of the page pointer to indicate whether it's
+ * a valid sg entry, or whether it points to the start of a new scatterlist.
+ * Those low bits are there for everyone! (thanks mason :-)
+ */
+#define sg_is_chain(sg) ((sg)->page_link & 0x01)
+#define sg_is_last(sg) ((sg)->page_link & 0x02)
+#define sg_chain_ptr(sg) \
+ ((struct scatterlist *) ((sg)->page_link & ~0x03))
+static inline struct scatterlist *sg_next(struct scatterlist *sg)
+{
+ if (sg_is_last(sg))
+ return NULL;
+
+ sg++;
+ if (unlikely(sg_is_chain(sg)))
+ sg = sg_chain_ptr(sg);
+
+ return sg;
+}
typedef __u16 u16;
@@ -109,13 +140,6 @@ static inline void kfree(void *p)
#define uninitialized_var(x) x = x
-# ifndef likely
-# define likely(x) (__builtin_expect(!!(x), 1))
-# endif
-# ifndef unlikely
-# define unlikely(x) (__builtin_expect(!!(x), 0))
-# endif
-
#define pr_err(format, ...) fprintf (stderr, format, ## __VA_ARGS__)
#ifdef DEBUG
#define pr_debug(format, ...) fprintf (stderr, format, ## __VA_ARGS__)
@@ -200,6 +224,13 @@ int virtqueue_add_buf(struct virtqueue *vq,
void *data,
gfp_t gfp);
+int virtqueue_add_sgs(struct virtqueue *vq,
+ struct scatterlist *sgs[],
+ unsigned int out_sgs,
+ unsigned int in_sgs,
+ void *data,
+ gfp_t gfp);
+
void virtqueue_kick(struct virtqueue *vq);
void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
--
MST
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