+static struct ioat_desc_sw *
+ioat2_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan)
+{
+ struct ioat_desc_sw *new;
+
+ /*
+ * used.prev points to where to start processing
+ * used.next points to next free descriptor
+ * if used.prev == NULL, there are none waiting to be processed
+ * if used.next == used.prev.prev, there is only one free descriptor,
+ * and we need to use it to as a noop descriptor before
+ * linking in a new set of descriptors, since the device
+ * has probably already read the pointer to it
+ */
+ if (ioat_chan->used_desc.prev &&
+ ioat_chan->used_desc.next == ioat_chan->used_desc.prev->prev) {
+
+ struct ioat_desc_sw *desc;
+ struct ioat_desc_sw *noop_desc;
+ int i;
+
+ /* set up the noop descriptor */
+ noop_desc = to_ioat_desc(ioat_chan->used_desc.next);
+ noop_desc->hw->size = 0;
+ noop_desc->hw->ctl = IOAT_DMA_DESCRIPTOR_NUL;
+ noop_desc->hw->src_addr = 0;
+ noop_desc->hw->dst_addr = 0;
+
+ ioat_chan->used_desc.next = ioat_chan->used_desc.next->next;
+ ioat_chan->pending++;
+ ioat_chan->dmacount++;
+
+ /* try to get a few more descriptors */
+ for (i = 16; i; i--) {
+ desc = ioat_dma_alloc_descriptor(ioat_chan, GFP_ATOMIC);
+ if (!desc) {
+ dev_err(&ioat_chan->device->pdev->dev,
+ "alloc failed\n");
+ break;
+ }
+ list_add_tail(&desc->node, ioat_chan->used_desc.next);
+
+ desc->hw->next
+ = to_ioat_desc(desc->node.next)->async_tx.phys;
+ to_ioat_desc(desc->node.prev)->hw->next
+ = desc->async_tx.phys;
+ ioat_chan->desccount++;
+ }
+
+ ioat_chan->used_desc.next = noop_desc->node.next;
+ }
+ new = to_ioat_desc(ioat_chan->used_desc.next);
+ prefetch(new);
+ ioat_chan->used_desc.next = new->node.next;
+
+ if (ioat_chan->used_desc.prev == NULL)
+ ioat_chan->used_desc.prev = &new->node;
+
+ prefetch(new->hw);
+ return new;
+}
+
+static struct ioat_desc_sw *ioat_dma_get_next_descriptor(
+ struct ioat_dma_chan *ioat_chan)
+{
+ if (!ioat_chan)
+ return NULL;
+
+ switch (ioat_chan->device->version) {
+ case IOAT_VER_1_2:
+ return ioat1_dma_get_next_descriptor(ioat_chan);
+ break;
+ case IOAT_VER_2_0:
+ return ioat2_dma_get_next_descriptor(ioat_chan);
+ break;
+ }
+ return NULL;
+}
+
+static struct dma_async_tx_descriptor *ioat1_dma_prep_memcpy(