diff options
| -rw-r--r-- | .clang-format | 1 | ||||
| -rw-r--r-- | drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c | 8 | ||||
| -rw-r--r-- | drivers/media/pci/intel/ipu3/ipu3-cio2.c | 4 | ||||
| -rw-r--r-- | include/linux/scatterlist.h | 49 | ||||
| -rw-r--r-- | lib/scatterlist.c | 26 |
5 files changed, 76 insertions, 12 deletions
diff --git a/.clang-format b/.clang-format index bc2ffb2a0b53..335ce29ab813 100644 --- a/.clang-format +++ b/.clang-format @@ -240,6 +240,7 @@ ForEachMacros: - 'for_each_set_bit' - 'for_each_set_bit_from' - 'for_each_sg' + - 'for_each_sg_dma_page' - 'for_each_sg_page' - 'for_each_sibling_event' - '__for_each_thread' diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c index 31786b200afc..a3357ff7540d 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c @@ -311,7 +311,13 @@ static dma_addr_t __vmw_piter_dma_addr(struct vmw_piter *viter) static dma_addr_t __vmw_piter_sg_addr(struct vmw_piter *viter) { - return sg_page_iter_dma_address(&viter->iter); + /* + * FIXME: This driver wrongly mixes DMA and CPU SG list iteration and + * needs revision. See + * https://lore.kernel.org/lkml/20190104223531.GA1705@ziepe.ca/ + */ + return sg_page_iter_dma_address( + container_of(&viter->iter, struct sg_dma_page_iter, base)); } diff --git a/drivers/media/pci/intel/ipu3/ipu3-cio2.c b/drivers/media/pci/intel/ipu3/ipu3-cio2.c index cdb79ae2d8dc..9fbfbda74171 100644 --- a/drivers/media/pci/intel/ipu3/ipu3-cio2.c +++ b/drivers/media/pci/intel/ipu3/ipu3-cio2.c @@ -846,7 +846,7 @@ static int cio2_vb2_buf_init(struct vb2_buffer *vb) unsigned int pages = DIV_ROUND_UP(vb->planes[0].length, CIO2_PAGE_SIZE); unsigned int lops = DIV_ROUND_UP(pages + 1, entries_per_page); struct sg_table *sg; - struct sg_page_iter sg_iter; + struct sg_dma_page_iter sg_iter; int i, j; if (lops <= 0 || lops > CIO2_MAX_LOPS) { @@ -873,7 +873,7 @@ static int cio2_vb2_buf_init(struct vb2_buffer *vb) b->offset = sg->sgl->offset; i = j = 0; - for_each_sg_page(sg->sgl, &sg_iter, sg->nents, 0) { + for_each_sg_dma_page (sg->sgl, &sg_iter, sg->nents, 0) { if (!pages--) break; b->lop[i][j] = sg_page_iter_dma_address(&sg_iter) >> PAGE_SHIFT; diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index b96f0d0b5b8f..b4be960c7e5d 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -339,12 +339,12 @@ int sg_alloc_table_chained(struct sg_table *table, int nents, /* * sg page iterator * - * Iterates over sg entries page-by-page. On each successful iteration, - * you can call sg_page_iter_page(@piter) and sg_page_iter_dma_address(@piter) - * to get the current page and its dma address. @piter->sg will point to the - * sg holding this page and @piter->sg_pgoffset to the page's page offset - * within the sg. The iteration will stop either when a maximum number of sg - * entries was reached or a terminating sg (sg_last(sg) == true) was reached. + * Iterates over sg entries page-by-page. On each successful iteration, you + * can call sg_page_iter_page(@piter) to get the current page and its dma + * address. @piter->sg will point to the sg holding this page and + * @piter->sg_pgoffset to the page's page offset within the sg. The iteration + * will stop either when a maximum number of sg entries was reached or a + * terminating sg (sg_last(sg) == true) was reached. */ struct sg_page_iter { struct scatterlist *sg; /* sg holding the page */ @@ -356,7 +356,19 @@ struct sg_page_iter { * next step */ }; +/* + * sg page iterator for DMA addresses + * + * This is the same as sg_page_iter however you can call + * sg_page_iter_dma_address(@dma_iter) to get the page's DMA + * address. sg_page_iter_page() cannot be called on this iterator. + */ +struct sg_dma_page_iter { + struct sg_page_iter base; +}; + bool __sg_page_iter_next(struct sg_page_iter *piter); +bool __sg_page_iter_dma_next(struct sg_dma_page_iter *dma_iter); void __sg_page_iter_start(struct sg_page_iter *piter, struct scatterlist *sglist, unsigned int nents, unsigned long pgoffset); @@ -372,11 +384,13 @@ static inline struct page *sg_page_iter_page(struct sg_page_iter *piter) /** * sg_page_iter_dma_address - get the dma address of the current page held by * the page iterator. - * @piter: page iterator holding the page + * @dma_iter: page iterator holding the page */ -static inline dma_addr_t sg_page_iter_dma_address(struct sg_page_iter *piter) +static inline dma_addr_t +sg_page_iter_dma_address(struct sg_dma_page_iter *dma_iter) { - return sg_dma_address(piter->sg) + (piter->sg_pgoffset << PAGE_SHIFT); + return sg_dma_address(dma_iter->base.sg) + + (dma_iter->base.sg_pgoffset << PAGE_SHIFT); } /** @@ -385,11 +399,28 @@ static inline dma_addr_t sg_page_iter_dma_address(struct sg_page_iter *piter) * @piter: page iterator to hold current page, sg, sg_pgoffset * @nents: maximum number of sg entries to iterate over * @pgoffset: starting page offset + * + * Callers may use sg_page_iter_page() to get each page pointer. */ #define for_each_sg_page(sglist, piter, nents, pgoffset) \ for (__sg_page_iter_start((piter), (sglist), (nents), (pgoffset)); \ __sg_page_iter_next(piter);) +/** + * for_each_sg_dma_page - iterate over the pages of the given sg list + * @sglist: sglist to iterate over + * @dma_iter: page iterator to hold current page + * @dma_nents: maximum number of sg entries to iterate over, this is the value + * returned from dma_map_sg + * @pgoffset: starting page offset + * + * Callers may use sg_page_iter_dma_address() to get each page's DMA address. + */ +#define for_each_sg_dma_page(sglist, dma_iter, dma_nents, pgoffset) \ + for (__sg_page_iter_start(&(dma_iter)->base, sglist, dma_nents, \ + pgoffset); \ + __sg_page_iter_dma_next(dma_iter);) + /* * Mapping sg iterator * diff --git a/lib/scatterlist.c b/lib/scatterlist.c index 9ba349e775ef..739dc9fe2c55 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -625,6 +625,32 @@ bool __sg_page_iter_next(struct sg_page_iter *piter) } EXPORT_SYMBOL(__sg_page_iter_next); +static int sg_dma_page_count(struct scatterlist *sg) +{ + return PAGE_ALIGN(sg->offset + sg_dma_len(sg)) >> PAGE_SHIFT; +} + +bool __sg_page_iter_dma_next(struct sg_dma_page_iter *dma_iter) +{ + struct sg_page_iter *piter = &dma_iter->base; + + if (!piter->__nents || !piter->sg) + return false; + + piter->sg_pgoffset += piter->__pg_advance; + piter->__pg_advance = 1; + + while (piter->sg_pgoffset >= sg_dma_page_count(piter->sg)) { + piter->sg_pgoffset -= sg_dma_page_count(piter->sg); + piter->sg = sg_next(piter->sg); + if (!--piter->__nents || !piter->sg) + return false; + } + + return true; +} +EXPORT_SYMBOL(__sg_page_iter_dma_next); + /** * sg_miter_start - start mapping iteration over a sg list * @miter: sg mapping iter to be started |