ioat3: xor support

ioat3.2 adds xor offload support for up to 8 sources.  It can also
perform an xor-zero-sum operation to validate whether all given sources
sum to zero, without writing to a destination.  Xor descriptors differ
from memcpy in that one operation may require multiple descriptors
depending on the number of sources.  When the number of sources exceeds
5 an extended descriptor is needed.  These descriptors need to be
accounted for when updating the DMA_COUNT register.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/dma/ioat/dma_v2.c b/drivers/dma/ioat/dma_v2.c
index 80ce32d..ee295d4 100644
--- a/drivers/dma/ioat/dma_v2.c
+++ b/drivers/dma/ioat/dma_v2.c
@@ -48,7 +48,7 @@
 MODULE_PARM_DESC(ioat_ring_max_alloc_order,
 		 "ioat2+: upper limit for dynamic ring resizing (default: n=16)");
 
-static void __ioat2_issue_pending(struct ioat2_dma_chan *ioat)
+void __ioat2_issue_pending(struct ioat2_dma_chan *ioat)
 {
 	void * __iomem reg_base = ioat->base.reg_base;