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Commit ceb5ac32 authored by Becky Bruce's avatar Becky Bruce Committed by Ingo Molnar
Browse files

swiotlb: comment corrections 



Impact: cleanup

swiotlb_map/unmap_single are now swiotlb_map/unmap_page;
trivially change all the comments to reference new names.

Also, there were some comments that should have been
referring to just plain old map_single, not swiotlb_map_single;
fix those as well.

Also change a use of the word "pointer", when what is
referred to is actually a dma/physical address.

Signed-off-by: default avatarBecky Bruce <beckyb@kernel.crashing.org>
Acked-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: default avatarKumar Gala <galak@kernel.crashing.org>
Cc: jeremy@goop.org
Cc: ian.campbell@citrix.com
LKML-Reference: <1239199761-22886-2-git-send-email-galak@kernel.crashing.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 577c9c45

lib/swiotlb.c

+11 −13
Original line number Diff line number Diff line
@@ -60,8 +60,8 @@ enum dma_sync_target { 
int swiotlb_force;



/*

 * Used to do a quick range check in swiotlb_unmap_single and

 * swiotlb_sync_single_*, to see if the memory was in fact allocated by this

 * Used to do a quick range check in unmap_single and

 * sync_single_*, to see if the memory was in fact allocated by this

 * API.

 */

static char *io_tlb_start, *io_tlb_end;
@@ -560,7 +560,6 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, 
				   size)) {

		/*

		 * The allocated memory isn't reachable by the device.

		 * Fall back on swiotlb_map_single().

		 */

		free_pages((unsigned long) ret, order);

		ret = NULL;
@@ -568,9 +567,8 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, 
	if (!ret) {

		/*

		 * We are either out of memory or the device can't DMA

		 * to GFP_DMA memory; fall back on

		 * swiotlb_map_single(), which will grab memory from

		 * the lowest available address range.

		 * to GFP_DMA memory; fall back on map_single(), which

		 * will grab memory from the lowest available address range.

		 */

		ret = map_single(hwdev, 0, size, DMA_FROM_DEVICE);

		if (!ret)
@@ -634,7 +632,7 @@ swiotlb_full(struct device *dev, size_t size, int dir, int do_panic) 
 * physical address to use is returned.

 *

 * Once the device is given the dma address, the device owns this memory until

 * either swiotlb_unmap_single or swiotlb_dma_sync_single is performed.

 * either swiotlb_unmap_page or swiotlb_dma_sync_single is performed.

 */

dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,

			    unsigned long offset, size_t size,
@@ -648,7 +646,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, 


	BUG_ON(dir == DMA_NONE);

	/*

	 * If the pointer passed in happens to be in the device's DMA window,

	 * If the address happens to be in the device's DMA window,

	 * we can safely return the device addr and not worry about bounce

	 * buffering it.

	 */
@@ -679,7 +677,7 @@ EXPORT_SYMBOL_GPL(swiotlb_map_page); 


/*

 * Unmap a single streaming mode DMA translation.  The dma_addr and size must

 * match what was provided for in a previous swiotlb_map_single call.  All

 * match what was provided for in a previous swiotlb_map_page call.  All

 * other usages are undefined.

 *

 * After this call, reads by the cpu to the buffer are guaranteed to see
@@ -703,7 +701,7 @@ EXPORT_SYMBOL_GPL(swiotlb_unmap_page); 
 * Make physical memory consistent for a single streaming mode DMA translation

 * after a transfer.

 *

 * If you perform a swiotlb_map_single() but wish to interrogate the buffer

 * If you perform a swiotlb_map_page() but wish to interrogate the buffer

 * using the cpu, yet do not wish to teardown the dma mapping, you must

 * call this function before doing so.  At the next point you give the dma

 * address back to the card, you must first perform a
@@ -777,7 +775,7 @@ EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_device); 


/*

 * Map a set of buffers described by scatterlist in streaming mode for DMA.

 * This is the scatter-gather version of the above swiotlb_map_single

 * This is the scatter-gather version of the above swiotlb_map_page

 * interface.  Here the scatter gather list elements are each tagged with the

 * appropriate dma address and length.  They are obtained via

 * sg_dma_{address,length}(SG).
@@ -788,7 +786,7 @@ EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_device); 
 *       The routine returns the number of addr/length pairs actually

 *       used, at most nents.

 *

 * Device ownership issues as mentioned above for swiotlb_map_single are the

 * Device ownership issues as mentioned above for swiotlb_map_page are the

 * same here.

 */

int
@@ -836,7 +834,7 @@ EXPORT_SYMBOL(swiotlb_map_sg); 


/*

 * Unmap a set of streaming mode DMA translations.  Again, cpu read rules

 * concerning calls here are the same as for swiotlb_unmap_single() above.

 * concerning calls here are the same as for swiotlb_unmap_page() above.

 */

void

swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,