1 files changed, 12 insertions, 21 deletions

diff --git a/drivers/dma/ioat/dma_v2.h b/drivers/dma/ioat/dma_v2.h
index ef2871fd786..a2c413b2b8d 100644
--- a/drivers/dma/ioat/dma_v2.h
+++ b/drivers/dma/ioat/dma_v2.h
@@ -22,6 +22,7 @@
 #define IOATDMA_V2_H
 
 #include <linux/dmaengine.h>
+#include <linux/circ_buf.h>
 #include "dma.h"
 #include "hw.h"
 
@@ -49,8 +50,9 @@ extern int ioat_ring_alloc_order;
  * @tail: cleanup index
  * @dmacount: identical to 'head' except for occasionally resetting to zero
  * @alloc_order: log2 of the number of allocated descriptors
+ * @produce: number of descriptors to produce at submit time
  * @ring: software ring buffer implementation of hardware ring
- * @ring_lock: protects ring attributes
+ * @prep_lock: serializes descriptor preparation (producers)
  */
 struct ioat2_dma_chan {
 	struct ioat_chan_common base;
@@ -60,8 +62,9 @@ struct ioat2_dma_chan {
 	u16 tail;
 	u16 dmacount;
 	u16 alloc_order;
+	u16 produce;
 	struct ioat_ring_ent **ring;
-	spinlock_t ring_lock;
+	spinlock_t prep_lock;
 };
 
 static inline struct ioat2_dma_chan *to_ioat2_chan(struct dma_chan *c)
@@ -71,38 +74,26 @@ static inline struct ioat2_dma_chan *to_ioat2_chan(struct dma_chan *c)
 	return container_of(chan, struct ioat2_dma_chan, base);
 }
 
-static inline u16 ioat2_ring_mask(struct ioat2_dma_chan *ioat)
+static inline u16 ioat2_ring_size(struct ioat2_dma_chan *ioat)
 {
-	return (1 << ioat->alloc_order) - 1;
+	return 1 << ioat->alloc_order;
 }
 
 /* count of descriptors in flight with the engine */
 static inline u16 ioat2_ring_active(struct ioat2_dma_chan *ioat)
 {
-	return (ioat->head - ioat->tail) & ioat2_ring_mask(ioat);
+	return CIRC_CNT(ioat->head, ioat->tail, ioat2_ring_size(ioat));
 }
 
 /* count of descriptors pending submission to hardware */
 static inline u16 ioat2_ring_pending(struct ioat2_dma_chan *ioat)
 {
-	return (ioat->head - ioat->issued) & ioat2_ring_mask(ioat);
+	return CIRC_CNT(ioat->head, ioat->issued, ioat2_ring_size(ioat));
 }
 
 static inline u16 ioat2_ring_space(struct ioat2_dma_chan *ioat)
 {
-	u16 num_descs = ioat2_ring_mask(ioat) + 1;
-	u16 active = ioat2_ring_active(ioat);
-
-	BUG_ON(active > num_descs);
-
-	return num_descs - active;
-}
-
-/* assumes caller already checked space */
-static inline u16 ioat2_desc_alloc(struct ioat2_dma_chan *ioat, u16 len)
-{
-	ioat->head += len;
-	return ioat->head - len;
+	return ioat2_ring_size(ioat) - ioat2_ring_active(ioat);
 }
 
 static inline u16 ioat2_xferlen_to_descs(struct ioat2_dma_chan *ioat, size_t len)
@@ -151,7 +142,7 @@ struct ioat_ring_ent {
 static inline struct ioat_ring_ent *
 ioat2_get_ring_ent(struct ioat2_dma_chan *ioat, u16 idx)
 {
-	return ioat->ring[idx & ioat2_ring_mask(ioat)];
+	return ioat->ring[idx & (ioat2_ring_size(ioat) - 1)];
 }
 
 static inline void ioat2_set_chainaddr(struct ioat2_dma_chan *ioat, u64 addr)
@@ -168,7 +159,7 @@ int __devinit ioat2_dma_probe(struct ioatdma_device *dev, int dca);
 int __devinit ioat3_dma_probe(struct ioatdma_device *dev, int dca);
 struct dca_provider * __devinit ioat2_dca_init(struct pci_dev *pdev, void __iomem *iobase);
 struct dca_provider * __devinit ioat3_dca_init(struct pci_dev *pdev, void __iomem *iobase);
-int ioat2_alloc_and_lock(u16 *idx, struct ioat2_dma_chan *ioat, int num_descs);
+int ioat2_check_space_lock(struct ioat2_dma_chan *ioat, int num_descs);
 int ioat2_enumerate_channels(struct ioatdma_device *device);
 struct dma_async_tx_descriptor *
 ioat2_dma_prep_memcpy_lock(struct dma_chan *c, dma_addr_t dma_dest,