From 8dc39cfca32c9a4e6deddaa0e76bd47d56f1876b Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom Date: Wed, 15 May 2019 17:45:23 +0200 Subject: drm/vmwgfx: Use the dma scatter-gather iterator to get dma addresses Use struct sg_dma_page_iter in favour struct of sg_page_iter, which fairly recently was declared useless for obtaining dma addresses. With a struct sg_dma_page_iter we can't call sg_page_iter_page() so when the page is needed, use the same page lookup mechanism as for the non-sg dma modes instead of calling sg_dma_page_iter. Note, the fixes tag doesn't really point to a commit introducing a failure / regression, but rather to a commit that implemented a simple workaround for this problem. Cc: Jason Gunthorpe Fixes: d901b2760dc6 ("lib/scatterlist: Provide a DMA page iterator") Signed-off-by: Thomas Hellstrom Reviewed-by: Jason Gunthorpe --- drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c | 27 +++++++-------------------- 1 file changed, 7 insertions(+), 20 deletions(-) (limited to 'drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c') diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c index a3357ff7540d..a6ea75b58a83 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c @@ -266,7 +266,9 @@ static bool __vmw_piter_non_sg_next(struct vmw_piter *viter) static bool __vmw_piter_sg_next(struct vmw_piter *viter) { - return __sg_page_iter_next(&viter->iter); + bool ret = __vmw_piter_non_sg_next(viter); + + return __sg_page_iter_dma_next(&viter->iter) && ret; } @@ -284,12 +286,6 @@ static struct page *__vmw_piter_non_sg_page(struct vmw_piter *viter) return viter->pages[viter->i]; } -static struct page *__vmw_piter_sg_page(struct vmw_piter *viter) -{ - return sg_page_iter_page(&viter->iter); -} - - /** * Helper functions to return the DMA address of the current page. * @@ -311,13 +307,7 @@ static dma_addr_t __vmw_piter_dma_addr(struct vmw_piter *viter) static dma_addr_t __vmw_piter_sg_addr(struct vmw_piter *viter) { - /* - * 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)); + return sg_page_iter_dma_address(&viter->iter); } @@ -336,26 +326,23 @@ void vmw_piter_start(struct vmw_piter *viter, const struct vmw_sg_table *vsgt, { viter->i = p_offset - 1; viter->num_pages = vsgt->num_pages; + viter->page = &__vmw_piter_non_sg_page; + viter->pages = vsgt->pages; switch (vsgt->mode) { case vmw_dma_phys: viter->next = &__vmw_piter_non_sg_next; viter->dma_address = &__vmw_piter_phys_addr; - viter->page = &__vmw_piter_non_sg_page; - viter->pages = vsgt->pages; break; case vmw_dma_alloc_coherent: viter->next = &__vmw_piter_non_sg_next; viter->dma_address = &__vmw_piter_dma_addr; - viter->page = &__vmw_piter_non_sg_page; viter->addrs = vsgt->addrs; - viter->pages = vsgt->pages; break; case vmw_dma_map_populate: case vmw_dma_map_bind: viter->next = &__vmw_piter_sg_next; viter->dma_address = &__vmw_piter_sg_addr; - viter->page = &__vmw_piter_sg_page; - __sg_page_iter_start(&viter->iter, vsgt->sgt->sgl, + __sg_page_iter_start(&viter->iter.base, vsgt->sgt->sgl, vsgt->sgt->orig_nents, p_offset); break; default: -- cgit v1.2.1