Commit 4c2d56c5 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Vinod Koul
Browse files

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: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: default avatarViresh Kumar <viresh.linux@gmail.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@linux.intel.com>
parent 236b106f

drivers/dma/dw_dmac.c

+18 −28
Original line number Original line Diff line number Diff line
@@ -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)

static void dwc_dump_chan_regs(struct dw_dma_chan *dwc)

{

{

	dev_err(chan2dev(&dwc->chan),

	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;

		return NULL;

	}

	}





	/*

	src_width = dst_width = dwc_fast_fls(src | dest | len);

	 * 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;





	ctllo = DWC_DEFAULT_CTLLO(chan)

	ctllo = DWC_DEFAULT_CTLLO(chan)

			| DWC_CTLL_DST_WIDTH(dst_width)

			| 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);

			mem = sg_dma_address(sg);

			len = sg_dma_len(sg);

			len = sg_dma_len(sg);





			if (!((mem | len) & 7))

			mem_width = dwc_fast_fls(mem | len);

				mem_width = 3;

			else if (!((mem | len) & 3))

				mem_width = 2;

			else if (!((mem | len) & 1))

				mem_width = 1;

			else

				mem_width = 0;





slave_sg_todev_fill_desc:

slave_sg_todev_fill_desc:

			desc = dwc_desc_get(dwc);

			desc = dwc_desc_get(dwc);
@@ -819,14 +816,7 @@ slave_sg_todev_fill_desc: 
			mem = sg_dma_address(sg);

			mem = sg_dma_address(sg);

			len = sg_dma_len(sg);

			len = sg_dma_len(sg);





			if (!((mem | len) & 7))

			mem_width = dwc_fast_fls(mem | len);

				mem_width = 3;

			else if (!((mem | len) & 3))

				mem_width = 2;

			else if (!((mem | len) & 1))

				mem_width = 1;

			else

				mem_width = 0;





slave_sg_fromdev_fill_desc:

slave_sg_fromdev_fill_desc:

			desc = dwc_desc_get(dwc);

			desc = dwc_desc_get(dwc);

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