[PATCH 1/2] ioat: convert to circ_buf

Dan Williams
2010-05-11T18:55:41Z

Use the common power-of-2 circular buffer macros.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---

drivers/dma/ioat/dma_v2.c | 2 +-
drivers/dma/ioat/dma_v2.h | 18 +++++++-----------
2 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/dma/ioat/dma_v2.c b/drivers/dma/ioat/dma_v2.c
index b5ae56c..b6699a3 100644
--- a/drivers/dma/ioat/dma_v2.c
+++ b/drivers/dma/ioat/dma_v2.c
@@ -553,7 +553,7 @@ bool reshape_ring(struct ioat2_dma_chan *ioat, int order)
*/
struct ioat_chan_common *chan = &ioat->base;
struct dma_chan *c = &chan->common;
- const u16 curr_size = ioat2_ring_mask(ioat) + 1;
+ const u16 curr_size = ioat2_ring_size(ioat);
const u16 active = ioat2_ring_active(ioat);
const u16 new_size = 1 << order;
struct ioat_ring_ent **ring;
diff --git a/drivers/dma/ioat/dma_v2.h b/drivers/dma/ioat/dma_v2.h
index ef2871f..d7b64f1 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"

@@ -71,31 +72,26 @@ 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;
+ return ioat2_ring_size(ioat) - ioat2_ring_active(ioat);
}

/* assumes caller already checked space */
@@ -151,7 +147,7 @@ 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)