On Tue, 4 Sep 2012 21:02:58 +0100
Chris Wilson <chris at chris-wilson.co.uk> wrote:
> By providing a callback for when we need to bind the pages, and then
> release them again later, we can shorten the amount of time we hold the
> foreign pages mapped and pinned, and importantly the dmabuf objects then
> behave as any other normal object with respect to the shrinker and
> memory management.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
with nitpicks below:
Reviewed-by: Ben Widawsky <ben at bwidawsk.net>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 1 -
> drivers/gpu/drm/i915/i915_gem.c | 10 ++++----
> drivers/gpu/drm/i915/i915_gem_dmabuf.c | 44 ++++++++++++++++++++++----------
> drivers/gpu/drm/i915/i915_gem_gtt.c | 4 +--
> 4 files changed, 37 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 1a714fa..a86f50d 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -998,7 +998,6 @@ struct drm_i915_gem_object {
> int pages_pin_count;
>
> /* prime dma-buf support */
> - struct sg_table *sg_table;
> void *dma_buf_vmapping;
> int vmapping_count;
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 06589a9..58075e3 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -1692,7 +1692,7 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj)
> {
> const struct drm_i915_gem_object_ops *ops = obj->ops;
>
> - if (obj->sg_table || obj->pages == NULL)
> + if (obj->pages == NULL)
> return 0;
>
> BUG_ON(obj->gtt_space);
> @@ -1838,7 +1838,7 @@ i915_gem_object_get_pages(struct drm_i915_gem_object *obj)
> const struct drm_i915_gem_object_ops *ops = obj->ops;
> int ret;
>
> - if (obj->sg_table || obj->pages)
> + if (obj->pages)
> return 0;
>
> BUG_ON(obj->pages_pin_count);
> @@ -3731,9 +3731,6 @@ void i915_gem_free_object(struct drm_gem_object *gem_obj)
>
> trace_i915_gem_object_destroy(obj);
>
> - if (gem_obj->import_attach)
> - drm_prime_gem_destroy(gem_obj, obj->sg_table);
> -
> if (obj->phys_obj)
> i915_gem_detach_phys_object(dev, obj);
>
> @@ -3755,6 +3752,9 @@ void i915_gem_free_object(struct drm_gem_object *gem_obj)
>
> BUG_ON(obj->pages);
>
> + if (obj->base.import_attach)
> + drm_prime_gem_destroy(&obj->base, NULL);
> +
> drm_gem_object_release(&obj->base);
> i915_gem_info_remove_obj(dev_priv, obj->base.size);
>
Was the order in which destroy happens moved intentionally?
> diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> index 4bb1b94..ca3497e 100644
> --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> @@ -82,7 +82,8 @@ out:
> }
>
> static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
> - struct sg_table *sg, enum dma_data_direction dir)
> + struct sg_table *sg,
> + enum dma_data_direction dir)
> {
> dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
> sg_free_table(sg);
I thought we frown upon unnecessary whitespace fixes in patches which
have behavioral changes?
> @@ -228,11 +229,35 @@ struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
> return dma_buf_export(obj, &i915_dmabuf_ops, obj->base.size, 0600);
> }
>
> +static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
> +{
> + struct sg_table *sg;
> +
> + sg = dma_buf_map_attachment(obj->base.import_attach, DMA_BIDIRECTIONAL);
> + if (IS_ERR(sg))
> + return PTR_ERR(sg);
> +
> + obj->pages = sg;
> + obj->has_dma_mapping = true;
> + return 0;
> +}
> +
> +static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj)
> +{
> + dma_buf_unmap_attachment(obj->base.import_attach,
> + obj->pages, DMA_BIDIRECTIONAL);
> + obj->has_dma_mapping = false;
> +}
> +
> +static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
> + .get_pages = i915_gem_object_get_pages_dmabuf,
> + .put_pages = i915_gem_object_put_pages_dmabuf,
> +};
> +
> struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
> struct dma_buf *dma_buf)
> {
> struct dma_buf_attachment *attach;
> - struct sg_table *sg;
> struct drm_i915_gem_object *obj;
> int ret;
>
> @@ -251,34 +276,25 @@ struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
> if (IS_ERR(attach))
> return ERR_CAST(attach);
>
> - sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
> - if (IS_ERR(sg)) {
> - ret = PTR_ERR(sg);
> - goto fail_detach;
> - }
>
> obj = kzalloc(sizeof(*obj), GFP_KERNEL);
> if (obj == NULL) {
> ret = -ENOMEM;
> - goto fail_unmap;
> + goto fail_detach;
> }
>
> ret = drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
> if (ret) {
> kfree(obj);
> - goto fail_unmap;
> + goto fail_detach;
> }
>
> - obj->has_dma_mapping = true;
> - obj->sg_table = sg;
> + i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
> obj->base.import_attach = attach;
>
> return &obj->base;
>
> -fail_unmap:
> - dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
> fail_detach:
> dma_buf_detach(dma_buf, attach);
> return ERR_PTR(ret);
> }
> -
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 6746109..c86dc59 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -234,7 +234,7 @@ void i915_ppgtt_bind_object(struct i915_hw_ppgtt *ppgtt,
> }
>
> i915_ppgtt_insert_sg_entries(ppgtt,
> - obj->sg_table ?: obj->pages,
> + obj->pages,
> obj->gtt_space->start >> PAGE_SHIFT,
> pte_flags);
> }
> @@ -325,7 +325,7 @@ void i915_gem_gtt_bind_object(struct drm_i915_gem_object *obj,
> struct drm_device *dev = obj->base.dev;
> unsigned int agp_type = cache_level_to_agp_type(dev, cache_level);
>
> - intel_gtt_insert_sg_entries(obj->sg_table ?: obj->pages,
> + intel_gtt_insert_sg_entries(obj->pages,
> obj->gtt_space->start >> PAGE_SHIFT,
> agp_type);
> obj->has_global_gtt_mapping = 1;
--
Ben Widawsky, Intel Open Source Technology Center
