diff options
author | Becky Bruce <beckyb@kernel.crashing.org> | 2009-04-08 10:09:15 -0400 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2009-04-08 10:18:35 -0400 |
commit | ceb5ac3264686e75e6951de6a18d4baa9bdecb92 (patch) | |
tree | 7e4f70b16dbb548ec8a428a701430da3acd896ec /lib/swiotlb.c | |
parent | 577c9c456f0e1371cbade38eaf91ae8e8a308555 (diff) |
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: Becky Bruce <beckyb@kernel.crashing.org>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Kumar 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: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'lib/swiotlb.c')
-rw-r--r-- | lib/swiotlb.c | 24 |
1 files changed, 11 insertions, 13 deletions
diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 2b0b5a7d2ced..170cf56af6a9 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c | |||
@@ -60,8 +60,8 @@ enum dma_sync_target { | |||
60 | int swiotlb_force; | 60 | int swiotlb_force; |
61 | 61 | ||
62 | /* | 62 | /* |
63 | * Used to do a quick range check in swiotlb_unmap_single and | 63 | * Used to do a quick range check in unmap_single and |
64 | * swiotlb_sync_single_*, to see if the memory was in fact allocated by this | 64 | * sync_single_*, to see if the memory was in fact allocated by this |
65 | * API. | 65 | * API. |
66 | */ | 66 | */ |
67 | static char *io_tlb_start, *io_tlb_end; | 67 | static char *io_tlb_start, *io_tlb_end; |
@@ -560,7 +560,6 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, | |||
560 | size)) { | 560 | size)) { |
561 | /* | 561 | /* |
562 | * The allocated memory isn't reachable by the device. | 562 | * The allocated memory isn't reachable by the device. |
563 | * Fall back on swiotlb_map_single(). | ||
564 | */ | 563 | */ |
565 | free_pages((unsigned long) ret, order); | 564 | free_pages((unsigned long) ret, order); |
566 | ret = NULL; | 565 | ret = NULL; |
@@ -568,9 +567,8 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, | |||
568 | if (!ret) { | 567 | if (!ret) { |
569 | /* | 568 | /* |
570 | * We are either out of memory or the device can't DMA | 569 | * We are either out of memory or the device can't DMA |
571 | * to GFP_DMA memory; fall back on | 570 | * to GFP_DMA memory; fall back on map_single(), which |
572 | * swiotlb_map_single(), which will grab memory from | 571 | * will grab memory from the lowest available address range. |
573 | * the lowest available address range. | ||
574 | */ | 572 | */ |
575 | ret = map_single(hwdev, 0, size, DMA_FROM_DEVICE); | 573 | ret = map_single(hwdev, 0, size, DMA_FROM_DEVICE); |
576 | if (!ret) | 574 | if (!ret) |
@@ -634,7 +632,7 @@ swiotlb_full(struct device *dev, size_t size, int dir, int do_panic) | |||
634 | * physical address to use is returned. | 632 | * physical address to use is returned. |
635 | * | 633 | * |
636 | * Once the device is given the dma address, the device owns this memory until | 634 | * Once the device is given the dma address, the device owns this memory until |
637 | * either swiotlb_unmap_single or swiotlb_dma_sync_single is performed. | 635 | * either swiotlb_unmap_page or swiotlb_dma_sync_single is performed. |
638 | */ | 636 | */ |
639 | dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, | 637 | dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, |
640 | unsigned long offset, size_t size, | 638 | unsigned long offset, size_t size, |
@@ -648,7 +646,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, | |||
648 | 646 | ||
649 | BUG_ON(dir == DMA_NONE); | 647 | BUG_ON(dir == DMA_NONE); |
650 | /* | 648 | /* |
651 | * If the pointer passed in happens to be in the device's DMA window, | 649 | * If the address happens to be in the device's DMA window, |
652 | * we can safely return the device addr and not worry about bounce | 650 | * we can safely return the device addr and not worry about bounce |
653 | * buffering it. | 651 | * buffering it. |
654 | */ | 652 | */ |
@@ -679,7 +677,7 @@ EXPORT_SYMBOL_GPL(swiotlb_map_page); | |||
679 | 677 | ||
680 | /* | 678 | /* |
681 | * Unmap a single streaming mode DMA translation. The dma_addr and size must | 679 | * Unmap a single streaming mode DMA translation. The dma_addr and size must |
682 | * match what was provided for in a previous swiotlb_map_single call. All | 680 | * match what was provided for in a previous swiotlb_map_page call. All |
683 | * other usages are undefined. | 681 | * other usages are undefined. |
684 | * | 682 | * |
685 | * After this call, reads by the cpu to the buffer are guaranteed to see | 683 | * After this call, reads by the cpu to the buffer are guaranteed to see |
@@ -703,7 +701,7 @@ EXPORT_SYMBOL_GPL(swiotlb_unmap_page); | |||
703 | * Make physical memory consistent for a single streaming mode DMA translation | 701 | * Make physical memory consistent for a single streaming mode DMA translation |
704 | * after a transfer. | 702 | * after a transfer. |
705 | * | 703 | * |
706 | * If you perform a swiotlb_map_single() but wish to interrogate the buffer | 704 | * If you perform a swiotlb_map_page() but wish to interrogate the buffer |
707 | * using the cpu, yet do not wish to teardown the dma mapping, you must | 705 | * using the cpu, yet do not wish to teardown the dma mapping, you must |
708 | * call this function before doing so. At the next point you give the dma | 706 | * call this function before doing so. At the next point you give the dma |
709 | * address back to the card, you must first perform a | 707 | * address back to the card, you must first perform a |
@@ -777,7 +775,7 @@ EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_device); | |||
777 | 775 | ||
778 | /* | 776 | /* |
779 | * Map a set of buffers described by scatterlist in streaming mode for DMA. | 777 | * Map a set of buffers described by scatterlist in streaming mode for DMA. |
780 | * This is the scatter-gather version of the above swiotlb_map_single | 778 | * This is the scatter-gather version of the above swiotlb_map_page |
781 | * interface. Here the scatter gather list elements are each tagged with the | 779 | * interface. Here the scatter gather list elements are each tagged with the |
782 | * appropriate dma address and length. They are obtained via | 780 | * appropriate dma address and length. They are obtained via |
783 | * sg_dma_{address,length}(SG). | 781 | * sg_dma_{address,length}(SG). |
@@ -788,7 +786,7 @@ EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_device); | |||
788 | * The routine returns the number of addr/length pairs actually | 786 | * The routine returns the number of addr/length pairs actually |
789 | * used, at most nents. | 787 | * used, at most nents. |
790 | * | 788 | * |
791 | * Device ownership issues as mentioned above for swiotlb_map_single are the | 789 | * Device ownership issues as mentioned above for swiotlb_map_page are the |
792 | * same here. | 790 | * same here. |
793 | */ | 791 | */ |
794 | int | 792 | int |
@@ -836,7 +834,7 @@ EXPORT_SYMBOL(swiotlb_map_sg); | |||
836 | 834 | ||
837 | /* | 835 | /* |
838 | * Unmap a set of streaming mode DMA translations. Again, cpu read rules | 836 | * Unmap a set of streaming mode DMA translations. Again, cpu read rules |
839 | * concerning calls here are the same as for swiotlb_unmap_single() above. | 837 | * concerning calls here are the same as for swiotlb_unmap_page() above. |
840 | */ | 838 | */ |
841 | void | 839 | void |
842 | swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, | 840 | swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, |