[Intel-gfx] [PATCH 5/7] drm/i915/skl: Support secondary (rotated) frame buffer mapping

Joonas Lahtinen joonas.lahtinen at linux.intel.com
Thu Mar 19 06:02:03 PDT 2015


On ti, 2015-03-17 at 15:45 +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> 90/270 rotated scanout needs a rotated GTT view of the framebuffer.
> 
> This is put in a separate VMA with a dedicated ggtt view and wired such that
> it is created when a framebuffer is pinned to a 90/270 rotated plane.
> 
> Rotation is only possible with Yb/Yf buffers and error is propagated to
> user space in case of a mismatch.
> 
> Special rotated page view is constructed at the VMA creation time by
> borrowing the DMA addresses from obj->pages.
> 
> v2:
>     * Do not bother with pages for rotated sg list, just populate the DMA
>       addresses. (Daniel Vetter)
>     * Checkpatch cleanup.
> 
> v3:
>     * Rebased on top of new plane handling (create rotated mapping when
>       setting the rotation property).
>     * Unpin rotated VMA on unpinning from display plane.
>     * Simplify rotation check using bitwise AND. (Chris Wilson)
> 
> v4:
>     * Fix unpinning of optional rotated mapping so it is really considered
>       to be optional.
> 
> v5:
>    * Rebased for fb modifier changes.
>    * Rebased for atomic commit.
>    * Only pin needed view for display. (Ville Syrjälä, Daniel Vetter)
> 
> v6:
>    * Rebased after preparatory work has been extracted out. (Daniel Vetter)
> 
> v7:
>    * Slightly simplified tiling geometry calculation.
>    * Moved rotated GGTT view implementation into i915_gem_gtt.c (Daniel Vetter)
> 
> v8:
>    * Do not use i915_gem_obj_size to get object size since that actually
>      returns the size of an VMA which may not exist.
>    * Rebased for ggtt view changes.
> 
> For: VIZ-4726
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Reviewed-by: Michel Thierry <michel.thierry at intel.com> (v4)
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_gem_gtt.c  | 113 ++++++++++++++++++++++++++++++++++-
>  drivers/gpu/drm/i915/i915_gem_gtt.h  |  12 ++++
>  drivers/gpu/drm/i915/intel_display.c |  29 ++++++++-
>  drivers/gpu/drm/i915/intel_drv.h     |   4 ++
>  4 files changed, 154 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index f1b9ea6..5381ebf 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -2413,15 +2413,119 @@ i915_gem_obj_lookup_or_create_ggtt_vma(struct drm_i915_gem_object *obj,
>  
>  }
>  
> +static
> +void rotate_pages(dma_addr_t *in, unsigned int width, unsigned int height,
> +		  struct sg_table *st)
> +{
> +	unsigned int column, row;
> +	unsigned int src_idx;
> +	struct scatterlist *sg = st->sgl;
> +
> +	st->nents = 0;
> +
> +	for (column = 0; column < width; column++) {
> +		src_idx = width * (height - 1) + column;
> +		for (row = 0; row < height; row++) {
> +			st->nents++;
> +			/* We don't need the pages, but need to initialize
> +			 * the entries so the sg list can be happily traversed.
> +			 * The only thing we need are DMA addresses.
> +			 */
> +			sg_set_page(sg, NULL, PAGE_SIZE, 0);
> +			sg_dma_address(sg) = in[src_idx];
> +			sg_dma_len(sg) = PAGE_SIZE;
> +			sg = sg_next(sg);
> +			src_idx -= width;
> +		}
> +	}
> +}
> +
> +static
> +struct sg_table *intel_rotate_fb_obj_pages(struct i915_ggtt_view *ggtt_view,
> +					   struct drm_i915_gem_object *obj)
> +{
> +	struct drm_device *dev = obj->base.dev;
> +	struct intel_rotation_info *rot_info = &ggtt_view->rotation_info;
> +	unsigned long size, pages, rot_pages;
> +	struct sg_page_iter sg_iter;
> +	unsigned long i;
> +	dma_addr_t *page_addr_list;
> +	struct sg_table *st;
> +	unsigned int tile_pitch, tile_height;
> +	unsigned int width_pages, height_pages;
> +	int ret = ENOMEM;
> +
> +	pages = obj->base.size / PAGE_SIZE;
> +
> +	/* Calculate tiling geometry. */
> +	tile_height = intel_tile_height(dev, rot_info->pixel_format,
> +					rot_info->fb_modifier);
> +	tile_pitch = PAGE_SIZE / tile_height;
> +	width_pages = DIV_ROUND_UP(rot_info->pitch, tile_pitch);
> +	height_pages = DIV_ROUND_UP(rot_info->height, tile_height);
> +	rot_pages = width_pages * height_pages;
> +	size = rot_pages * PAGE_SIZE;
> +
> +	/* Allocate a temporary list of source pages for random access. */
> +	page_addr_list = drm_malloc_ab(pages, sizeof(dma_addr_t));
> +	if (!page_addr_list)
> +		return ERR_PTR(ret);
> +
> +	/* Allocate target SG list. */
> +	st = kmalloc(sizeof(*st), GFP_KERNEL);
> +	if (!st)
> +		goto err_st_alloc;
> +
> +	ret = sg_alloc_table(st, rot_pages, GFP_KERNEL);
> +	if (ret)
> +		goto err_sg_alloc;
> +
> +	/* Populate source page list from the object. */
> +	i = 0;
> +	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) {
> +		page_addr_list[i] = sg_page_iter_dma_address(&sg_iter);
> +		i++;
> +	}
> +
> +	/* Rotate the pages. */
> +	rotate_pages(page_addr_list, width_pages, height_pages, st);
> +
> +	DRM_DEBUG_KMS(
> +		      "Created rotated page mapping for object size %lu (pitch=%u, height=%u, pixel_format=0x%x, %ux%u tiles, %lu pages).\n",
> +		      size, rot_info->pitch, rot_info->height,
> +		      rot_info->pixel_format, width_pages, height_pages,
> +		      rot_pages);
> +
> +	drm_free_large(page_addr_list);
> +
> +	return st;
> +
> +err_sg_alloc:
> +	kfree(st);
> +err_st_alloc:
> +	drm_free_large(page_addr_list);
> +
> +	DRM_DEBUG_KMS(
> +		      "Failed to create rotated mapping for object size %lu! (%d) (pitch=%u, height=%u, pixel_format=0x%x, %ux%u tiles, %lu pages)\n",
> +		      size, ret, rot_info->pitch, rot_info->height,
> +		      rot_info->pixel_format, width_pages, height_pages,
> +		      rot_pages);
> +	return ERR_PTR(ret);
> +}
>  
>  static inline
>  int i915_get_ggtt_vma_pages(struct i915_vma *vma)

Same rant about function signatures as on earlier patch, put all on the
same line like most of new the code has it.

>  {
> +	int ret = 0;
> +
>  	if (vma->ggtt_view.pages)
>  		return 0;
>  
>  	if (vma->ggtt_view.type == I915_GGTT_VIEW_NORMAL)
>  		vma->ggtt_view.pages = vma->obj->pages;
> +	else if (vma->ggtt_view.type == I915_GGTT_VIEW_ROTATED)
> +		vma->ggtt_view.pages =
> +			intel_rotate_fb_obj_pages(&vma->ggtt_view, vma->obj);
>  	else
>  		WARN_ONCE(1, "GGTT view %u not implemented!\n",
>  			  vma->ggtt_view.type);
> @@ -2429,10 +2533,15 @@ int i915_get_ggtt_vma_pages(struct i915_vma *vma)
>  	if (!vma->ggtt_view.pages) {
>  		DRM_ERROR("Failed to get pages for GGTT view type %u!\n",
>  			  vma->ggtt_view.type);
> -		return -EINVAL;
> +		ret = -EINVAL;
> +	} else if (IS_ERR(vma->ggtt_view.pages)) {
> +		ret = PTR_ERR(vma->ggtt_view.pages);
> +		vma->ggtt_view.pages = NULL;
> +		DRM_ERROR("Failed to get pages for VMA view type %u (%d)!\n",
> +			  vma->ggtt_view.type, ret);
>  	}
>  
> -	return 0;
> +	return ret;
>  }
>  
>  /**
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
> index c9e93f5..a61e8dd 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.h
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
> @@ -111,12 +111,24 @@ typedef gen8_gtt_pte_t gen8_ppgtt_pde_t;
>  
>  enum i915_ggtt_view_type {
>  	I915_GGTT_VIEW_NORMAL = 0,
> +	I915_GGTT_VIEW_ROTATED
> +};
> +
> +struct intel_rotation_info {
> +	unsigned int height;
> +	unsigned int pitch;
> +	uint32_t pixel_format;
> +	uint64_t fb_modifier;
>  };
>  
>  struct i915_ggtt_view {
>  	enum i915_ggtt_view_type type;
>  
>  	struct sg_table *pages;
> +
> +	union {
> +		struct intel_rotation_info rotation_info;
> +	};

In preparation for the memcmp way of comparing views, I would move this
be before the variable struct parts (namely sg_table *pages), and also
wrap it once more so the result would be like this:

[snip]
enum i915_ggtt_view_type type;

union {
	struct {
		struct intel_rotation_info info;
	} rotated;
	struct {
		...
	} partial;
};

// private bits go here, to be wrapped in their struct with view
// type comparing patches

struct sg_table *pages;
[snip]

That way it's clear which view owns what.

>  };
>  
>  extern const struct i915_ggtt_view i915_ggtt_view_normal;
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index fe11e99..c2c3a76 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -2194,7 +2194,7 @@ static bool need_vtd_wa(struct drm_device *dev)
>  	return false;
>  }
>  
> -static unsigned int
> +unsigned int
>  intel_tile_height(struct drm_device *dev, uint32_t pixel_format,
>  		  uint64_t fb_format_modifier)
>  {
> @@ -2254,9 +2254,34 @@ int intel_fill_fb_ggtt_view(struct i915_ggtt_view *view,
>  			    struct drm_framebuffer *fb,
>  			    const struct drm_plane_state *plane_state)
>  {
> +	struct intel_rotation_info *info = &view->rotation_info;
> +	static const struct i915_ggtt_view rotated_view =
> +				{ .type = I915_GGTT_VIEW_ROTATED };
> +
>  	*view = i915_ggtt_view_normal;
>  
> -	return 0;
> +	if (!plane_state)
> +		return 0;
> +
> +	if (!(plane_state->rotation &
> +	    (BIT(DRM_ROTATE_90) | BIT(DRM_ROTATE_270))))
> +		return 0;

Should the rotation checking helper introduced in previous patch be used
here too?

> +
> +	*view = rotated_view;
> +
> +	info->height = fb->height;
> +	info->pixel_format = fb->pixel_format;
> +	info->pitch = fb->pitches[0];
> +	info->fb_modifier = fb->modifier[0];
> +
> +	if (!(info->fb_modifier == I915_FORMAT_MOD_Y_TILED ||
> +	      info->fb_modifier == I915_FORMAT_MOD_Yf_TILED)) {
> +		DRM_DEBUG_KMS(
> +			      "Y or Yf tiling is needed for 90/270 rotation!\n");
> +		return -EINVAL;
> +	}
> +
> +	return 1;
>  }
>  
>  int
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 3721878..53a1372 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -987,6 +987,10 @@ int intel_plane_atomic_set_property(struct drm_plane *plane,
>  				    struct drm_property *property,
>  				    uint64_t val);
>  
> +unsigned int
> +intel_tile_height(struct drm_device *dev, uint32_t pixel_format,
> +		  uint64_t fb_format_modifier);
> +
>  /* shared dpll functions */
>  struct intel_shared_dpll *intel_crtc_to_shared_dpll(struct intel_crtc *crtc);
>  void assert_shared_dpll(struct drm_i915_private *dev_priv,




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