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Commit 9bb2bcdb authored by Ben Collins's avatar Ben Collins
Browse files

ieee1394: speed up of dma_region_sync_for_cpu 



when attempting to find the 'last' part of the dma region continue the
search from where we left off, instead of starting the search over.

Signed-off-by: default avatarJim Westfall <jwestfall@surrealistic.net>
Signed-off-by: default avatarBen Collins <bcollins@ubuntu.com>
parent f54b1bdf

drivers/ieee1394/dma.c

+9 −9
Original line number Diff line number Diff line
@@ -145,12 +145,12 @@ void dma_region_free(struct dma_region *dma) 
/* find the scatterlist index and remaining offset corresponding to a

   given offset from the beginning of the buffer */

static inline int dma_region_find(struct dma_region *dma, unsigned long offset,

				  unsigned long *rem)

				  unsigned int start, unsigned long *rem)

{

	int i;

	unsigned long off = offset;



	for (i = 0; i < dma->n_dma_pages; i++) {

	for (i = start; i < dma->n_dma_pages; i++) {

		if (off < sg_dma_len(&dma->sglist[i])) {

			*rem = off;

			break;
@@ -170,7 +170,7 @@ dma_addr_t dma_region_offset_to_bus(struct dma_region * dma, 
	unsigned long rem = 0;



	struct scatterlist *sg =

	    &dma->sglist[dma_region_find(dma, offset, &rem)];

	    &dma->sglist[dma_region_find(dma, offset, 0, &rem)];

	return sg_dma_address(sg) + rem;

}
@@ -178,13 +178,13 @@ void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset, 
			     unsigned long len)

{

	int first, last;

	unsigned long rem;

	unsigned long rem = 0;



	if (!len)

		len = 1;



	first = dma_region_find(dma, offset, &rem);

	last = dma_region_find(dma, offset + len - 1, &rem);

	first = dma_region_find(dma, offset, 0, &rem);

	last = dma_region_find(dma, rem + len - 1, first, &rem);



	pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1,

				dma->direction);
@@ -194,13 +194,13 @@ void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset, 
				unsigned long len)

{

	int first, last;

	unsigned long rem;

	unsigned long rem = 0;



	if (!len)

		len = 1;



	first = dma_region_find(dma, offset, &rem);

	last = dma_region_find(dma, offset + len - 1, &rem);

	first = dma_region_find(dma, offset, 0, &rem);

	last = dma_region_find(dma, rem + len - 1, first, &rem);



	pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first],

				   last - first + 1, dma->direction);