dmaengine: ioat: fixing chunk sizing macros dependency

changing macros which assumption is chunk size of 2M,
which can be other size
prepare for changing allocation chunk size.

Acked-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Leonid Ravich <Leonid.Ravich@emc.com>
Link: https://lore.kernel.org/r/20200416170628.16196-1-leonid.ravich@dell.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h
index b8e8e0b..5216c6b 100644
--- a/drivers/dma/ioat/dma.h
+++ b/drivers/dma/ioat/dma.h
@@ -81,6 +81,11 @@ struct ioatdma_device {
 	u32 msixpba;
 };
 
+#define IOAT_MAX_ORDER 16
+#define IOAT_MAX_DESCS (1 << IOAT_MAX_ORDER)
+#define IOAT_CHUNK_SIZE (SZ_2M)
+#define IOAT_DESCS_PER_CHUNK (IOAT_CHUNK_SIZE / IOAT_DESC_SZ)
+
 struct ioat_descs {
 	void *virt;
 	dma_addr_t hw;
@@ -128,7 +133,7 @@ struct ioatdma_chan {
 	u16 produce;
 	struct ioat_ring_ent **ring;
 	spinlock_t prep_lock;
-	struct ioat_descs descs[2];
+	struct ioat_descs descs[IOAT_MAX_DESCS / IOAT_DESCS_PER_CHUNK];
 	int desc_chunks;
 	int intr_coalesce;
 	int prev_intr_coalesce;
@@ -301,9 +306,6 @@ static inline bool is_ioat_bug(unsigned long err)
 	return !!err;
 }
 
-#define IOAT_MAX_ORDER 16
-#define IOAT_MAX_DESCS 65536
-#define IOAT_DESCS_PER_2M 32768
 
 static inline u32 ioat_ring_size(struct ioatdma_chan *ioat_chan)
 {