I've just been talking with Ben about nouveau having some issues since
this path,
ttm_resource can be subclassed by drivers, and the code below that
copies ttm_resources around pretty much seems to destroy that.
> + struct ttm_resource *src_mem = &bo->mem;
> + struct ttm_resource_manager *src_man =
> + ttm_manager_type(bdev, src_mem->mem_type);
> + struct ttm_resource src_copy = *src_mem;
This here ^^
> + union {
> + struct ttm_kmap_iter_tt tt;
> + struct ttm_kmap_iter_linear_io io;
> + } _dst_iter, _src_iter;
> + struct ttm_kmap_iter *dst_iter, *src_iter;
> + int ret = 0;
>
> - /*
> - * TTM might be null for moves within the same region.
> - */
> - if (ttm) {
> + if (ttm && ((ttm->page_flags & TTM_PAGE_FLAG_SWAPPED) ||
> + dst_man->use_tt)) {
> ret = ttm_tt_populate(bdev, ttm, ctx);
> if (ret)
> - goto out1;
> + return ret;
> }
>
> - for (i = 0; i < new_mem->num_pages; ++i) {
> - if (old_iomap == NULL) {
> - pgprot_t prot = ttm_io_prot(bo, old_mem, PAGE_KERNEL);
> - ret = ttm_copy_ttm_io_page(ttm, new_iomap, i,
> - prot);
> - } else if (new_iomap == NULL) {
> - pgprot_t prot = ttm_io_prot(bo, new_mem, PAGE_KERNEL);
> - ret = ttm_copy_io_ttm_page(ttm, old_iomap, i,
> - prot);
> - } else {
> - ret = ttm_copy_io_page(new_iomap, old_iomap, i);
> - }
> - if (ret)
> - goto out1;
> + dst_iter = ttm_kmap_iter_linear_io_init(&_dst_iter.io, bdev, dst_mem);
> + if (PTR_ERR(dst_iter) == -EINVAL && dst_man->use_tt)
> + dst_iter = ttm_kmap_iter_tt_init(&_dst_iter.tt, bo->ttm);
> + if (IS_ERR(dst_iter))
> + return PTR_ERR(dst_iter);
> +
> + src_iter = ttm_kmap_iter_linear_io_init(&_src_iter.io, bdev, src_mem);
> + if (PTR_ERR(src_iter) == -EINVAL && src_man->use_tt)
> + src_iter = ttm_kmap_iter_tt_init(&_src_iter.tt, bo->ttm);
> + if (IS_ERR(src_iter)) {
> + ret = PTR_ERR(src_iter);
> + goto out_src_iter;
> }
> - mb();
> -out2:
> - old_copy = *old_mem;
>
> - ttm_bo_assign_mem(bo, new_mem);
> -
> - if (!man->use_tt)
> - ttm_bo_tt_destroy(bo);
> + ttm_move_memcpy(bo, dst_mem->num_pages, dst_iter, src_iter);
> + src_copy = *src_mem;
> + ttm_bo_move_sync_cleanup(bo, dst_mem);
>
> -out1:
> - ttm_resource_iounmap(bdev, old_mem, new_iomap);
> -out:
> - ttm_resource_iounmap(bdev, &old_copy, old_iomap);
> + if (!src_iter->ops->maps_tt)
> + ttm_kmap_iter_linear_io_fini(&_src_iter.io, bdev, &src_copy);
passes a copy into linear_io_fini which calls the driver io_mem_free
without the subclass data.
Dave.
