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

Tvrtko Ursulin
2015-03-05T14:08:03Z

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)

For: VIZ-4726
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Michel Thierry <michel.thierry@intel.com> (v4)
---
drivers/gpu/drm/i915/i915_gem_gtt.c | 116 ++++++++++++++++++++++++++++++++++-
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, 157 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 74df3d1..084aac1 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -2372,14 +2372,121 @@ i915_gem_obj_lookup_or_create_vma_view(struct drm_i915_gem_object *obj,
return vma;
}

+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 drm_i915_private *dev_priv = dev->dev_private;
+ struct i915_address_space *ggtt = &dev_priv->gtt.base;
+ 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 = i915_gem_obj_size(obj, ggtt) / 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_vma_pages(struct i915_vma *vma)
{
+ 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);
@@ -2387,10 +2494,15 @@ int i915_get_vma_pages(struct i915_vma *vma)
if (!vma->ggtt_view.pages) {
DRM_ERROR("Failed to get pages for VMA 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;
+ };
};

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 8157999..9867f55 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2189,7 +2189,7 @@ 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)
{
@@ -2249,9 +2249,34 @@ 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;
+
+ *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 9b96d48..67b21cf 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -983,6 +983,10 @@ 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,