mirror of https://gitee.com/openkylin/linux.git
drm: exynos: fix for mapping of dma buffers
This patch fixes the problem of mapping contigous and non contigous dma buffers. Currently page struct is calculated from the buf->dma_addr which is not the physical address. It is replaced by buf->pages which points to the page struct of the first page of contigous memory chunk. This gives the correct page frame number for mapping. Non-contigous dma buffers are described using SG table and SG lists. Each valid SG List is pointing to a single page or group of pages which are physically contigous. Current implementation just maps the first page of each SG List and leave the other pages unmapped, leading to a crash. Given solution finds the page struct for the faulting page through parsing SG table and map it. Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com> Signed-off-by: Inki Dae <inki.dae@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
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ea6d66c3a7
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4ddc404bc0
drivers/gpu/drm/exynos
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@ -95,15 +95,37 @@ static int exynos_drm_gem_map_buf(struct drm_gem_object *obj,
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{
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struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
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struct exynos_drm_gem_buf *buf = exynos_gem_obj->buffer;
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struct scatterlist *sgl;
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unsigned long pfn;
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int i;
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if (exynos_gem_obj->flags & EXYNOS_BO_NONCONTIG) {
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if (!buf->sgt)
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return -EINTR;
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sgl = buf->sgt->sgl;
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for_each_sg(buf->sgt->sgl, sgl, buf->sgt->nents, i) {
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if (!sgl) {
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DRM_ERROR("invalid SG table\n");
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return -EINTR;
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}
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if (page_offset < (sgl->length >> PAGE_SHIFT))
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break;
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page_offset -= (sgl->length >> PAGE_SHIFT);
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}
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if (i >= buf->sgt->nents) {
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DRM_ERROR("invalid page offset\n");
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return -EINVAL;
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}
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pfn = __phys_to_pfn(sg_phys(sgl)) + page_offset;
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} else {
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if (!buf->pages)
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return -EINTR;
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pfn = page_to_pfn(buf->pages[page_offset++]);
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} else
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pfn = (buf->dma_addr >> PAGE_SHIFT) + page_offset;
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pfn = page_to_pfn(buf->pages[0]) + page_offset;
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}
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return vm_insert_mixed(vma, f_vaddr, pfn);
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}
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