virtio: add_buf_gfp
Michael S. Tsirkin [Thu, 29 Apr 2010 14:26:37 +0000 (17:26 +0300)]
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>

drivers/virtio/virtio_ring.c
include/linux/virtio.h

index 0717b5b..1ca8890 100644 (file)
@@ -110,13 +110,14 @@ struct vring_virtqueue
 static int vring_add_indirect(struct vring_virtqueue *vq,
                              struct scatterlist sg[],
                              unsigned int out,
-                             unsigned int in)
+                             unsigned int in,
+                             gfp_t gfp)
 {
        struct vring_desc *desc;
        unsigned head;
        int i;
 
-       desc = kmalloc((out + in) * sizeof(struct vring_desc), GFP_ATOMIC);
+       desc = kmalloc((out + in) * sizeof(struct vring_desc), gfp);
        if (!desc)
                return vq->vring.num;
 
@@ -155,11 +156,12 @@ static int vring_add_indirect(struct vring_virtqueue *vq,
        return head;
 }
 
-int virtqueue_add_buf(struct virtqueue *_vq,
-                 struct scatterlist sg[],
-                 unsigned int out,
-                 unsigned int in,
-                 void *data)
+int virtqueue_add_buf_gfp(struct virtqueue *_vq,
+                         struct scatterlist sg[],
+                         unsigned int out,
+                         unsigned int in,
+                         void *data,
+                         gfp_t gfp)
 {
        struct vring_virtqueue *vq = to_vvq(_vq);
        unsigned int i, avail, head, uninitialized_var(prev);
@@ -171,7 +173,7 @@ int virtqueue_add_buf(struct virtqueue *_vq,
        /* If the host supports indirect descriptor tables, and we have multiple
         * buffers, then go indirect. FIXME: tune this threshold */
        if (vq->indirect && (out + in) > 1 && vq->num_free) {
-               head = vring_add_indirect(vq, sg, out, in);
+               head = vring_add_indirect(vq, sg, out, in, gfp);
                if (head != vq->vring.num)
                        goto add_head;
        }
@@ -232,7 +234,7 @@ add_head:
                return vq->num_free ? vq->vring.num : 0;
        return vq->num_free;
 }
-EXPORT_SYMBOL_GPL(virtqueue_add_buf);
+EXPORT_SYMBOL_GPL(virtqueue_add_buf_gfp);
 
 void virtqueue_kick(struct virtqueue *_vq)
 {
index 5b0fce0..aff5b4f 100644 (file)
@@ -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);