virtio: add_buf_gfp

Add an add_buf variant that gets gfp parameter. Use that
to allocate indirect buffers.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 17 insertions, 5 deletions

diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 5b0fce0d2aa2..aff5b4f74041 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -7,6 +7,7 @@
 #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.
@@ -32,6 +33,7 @@ struct virtqueue {
  *      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.
+ *      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
@@ -60,11 +62,21 @@ struct virtqueue {
  * All operations can be called in any context.
  */
 
-int virtqueue_add_buf(struct virtqueue *vq,
-                      struct scatterlist sg[],
-                      unsigned int out_num,
-                      unsigned int in_num,
-                      void *data);
+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 virtqueue_kick(struct virtqueue *vq);