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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2012-06-19 13:34:08 +0300
committerVinod Koul <vinod.koul@linux.intel.com>2012-06-21 08:05:38 +0530
commit4c2d56c574db84ef6e0101f28a37c044e89b0302 (patch)
tree5570d474ccabcf1fafe60cc4466eff2cbc41b866 /drivers/dma
parent236b106f1a66a272708e4960cde8cbcdd1611435 (diff)
dw_dmac: introduce dwc_fast_fls()
There were three places where such function is used. We still avoid to use native fls() because in one case it requires to use 64bit version which is suboptimal in our case. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Viresh Kumar <viresh.linux@gmail.com> Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/dw_dmac.c46
1 files changed, 18 insertions, 28 deletions
diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index d3038a03503d..6b456f042557 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -191,6 +191,21 @@ static void dwc_initialize(struct dw_dma_chan *dwc)
/*----------------------------------------------------------------------*/
+static inline unsigned int dwc_fast_fls(unsigned long long v)
+{
+ /*
+ * We can be a lot more clever here, but this should take care
+ * of the most common optimization.
+ */
+ if (!(v & 7))
+ return 3;
+ else if (!(v & 3))
+ return 2;
+ else if (!(v & 1))
+ return 1;
+ return 0;
+}
+
static void dwc_dump_chan_regs(struct dw_dma_chan *dwc)
{
dev_err(chan2dev(&dwc->chan),
@@ -641,18 +656,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
return NULL;
}
- /*
- * We can be a lot more clever here, but this should take care
- * of the most common optimization.
- */
- if (!((src | dest | len) & 7))
- src_width = dst_width = 3;
- else if (!((src | dest | len) & 3))
- src_width = dst_width = 2;
- else if (!((src | dest | len) & 1))
- src_width = dst_width = 1;
- else
- src_width = dst_width = 0;
+ src_width = dst_width = dwc_fast_fls(src | dest | len);
ctllo = DWC_DEFAULT_CTLLO(chan)
| DWC_CTLL_DST_WIDTH(dst_width)
@@ -752,14 +756,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
mem = sg_dma_address(sg);
len = sg_dma_len(sg);
- if (!((mem | len) & 7))
- mem_width = 3;
- else if (!((mem | len) & 3))
- mem_width = 2;
- else if (!((mem | len) & 1))
- mem_width = 1;
- else
- mem_width = 0;
+ mem_width = dwc_fast_fls(mem | len);
slave_sg_todev_fill_desc:
desc = dwc_desc_get(dwc);
@@ -819,14 +816,7 @@ slave_sg_todev_fill_desc:
mem = sg_dma_address(sg);
len = sg_dma_len(sg);
- if (!((mem | len) & 7))
- mem_width = 3;
- else if (!((mem | len) & 3))
- mem_width = 2;
- else if (!((mem | len) & 1))
- mem_width = 1;
- else
- mem_width = 0;
+ mem_width = dwc_fast_fls(mem | len);
slave_sg_fromdev_fill_desc:
desc = dwc_desc_get(dwc);