qxl: convert qxl driver to proper use for reservations

The recent addition of lockdep support to reservations and their subsequent
use by TTM showed up a number of potential problems with the way qxl was using
TTM objects.

a) it was allocating objects, and reserving them later without validating
underneath the reservation, which meant in extreme conditions the objects could
be evicted before the reservation ever used them.

b) it was reserving objects straight after allocating them, but with no
ability to back off should the reservations fail. It now allocates the necessary
objects then does a complete reservation pass on them to avoid deadlocks.

c) it had two lists per release tracking objects, unnecessary complicating
the reservation process.

This patch removes the dual object tracking, adds reservations ticket support
to the release and fence object handling. It then ports the internal fb
drawing code and the userspace facing ioctl to use the new interfaces properly,
along with cleanup up the error path handling in some codepaths.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 180 insertions, 83 deletions

diff --git a/drivers/gpu/drm/qxl/qxl_draw.c b/drivers/gpu/drm/qxl/qxl_draw.c
index 3c8c3dbf9378..56e1d633875e 100644
--- a/drivers/gpu/drm/qxl/qxl_draw.c
+++ b/drivers/gpu/drm/qxl/qxl_draw.c
@@ -23,25 +23,29 @@
 #include "qxl_drv.h"
 #include "qxl_object.h"
 
+static int alloc_clips(struct qxl_device *qdev,
+		       struct qxl_release *release,
+		       unsigned num_clips,
+		       struct qxl_bo **clips_bo)
+{
+	int size = sizeof(struct qxl_clip_rects) + sizeof(struct qxl_rect) * num_clips;
+
+	return qxl_alloc_bo_reserved(qdev, release, size, clips_bo);
+}
+
 /* returns a pointer to the already allocated qxl_rect array inside
  * the qxl_clip_rects. This is *not* the same as the memory allocated
  * on the device, it is offset to qxl_clip_rects.chunk.data */
 static struct qxl_rect *drawable_set_clipping(struct qxl_device *qdev,
 					      struct qxl_drawable *drawable,
 					      unsigned num_clips,
-					      struct qxl_bo **clips_bo,
-					      struct qxl_release *release)
+					      struct qxl_bo *clips_bo)
 {
 	struct qxl_clip_rects *dev_clips;
 	int ret;
-	int size = sizeof(*dev_clips) + sizeof(struct qxl_rect) * num_clips;
-	ret = qxl_alloc_bo_reserved(qdev, size, clips_bo);
-	if (ret)
-		return NULL;
 
-	ret = qxl_bo_kmap(*clips_bo, (void **)&dev_clips);
+	ret = qxl_bo_kmap(clips_bo, (void **)&dev_clips);
 	if (ret) {
-		qxl_bo_unref(clips_bo);
 		return NULL;
 	}
 	dev_clips->num_rects = num_clips;
@@ -52,20 +56,34 @@ static struct qxl_rect *drawable_set_clipping(struct qxl_device *qdev,
 }
 
 static int
+alloc_drawable(struct qxl_device *qdev, struct qxl_release **release)
+{
+	int ret;
+	ret = qxl_alloc_release_reserved(qdev, sizeof(struct qxl_drawable),
+					 QXL_RELEASE_DRAWABLE, release,
+					 NULL);
+	return ret;
+}
+
+static void
+free_drawable(struct qxl_device *qdev, struct qxl_release *release)
+{
+	qxl_release_free(qdev, release);
+}
+
+/* release needs to be reserved at this point */
+static int
 make_drawable(struct qxl_device *qdev, int surface, uint8_t type,
 	      const struct qxl_rect *rect,
-	      struct qxl_release **release)
+	      struct qxl_release *release)
 {
 	struct qxl_drawable *drawable;
-	int i, ret;
+	int i;
 
-	ret = qxl_alloc_release_reserved(qdev, sizeof(*drawable),
-					 QXL_RELEASE_DRAWABLE, release,
-					 NULL);
-	if (ret)
-		return ret;
+	drawable = (struct qxl_drawable *)qxl_release_map(qdev, release);
+	if (!drawable)
+		return -ENOMEM;
 
-	drawable = (struct qxl_drawable *)qxl_release_map(qdev, *release);
 	drawable->type = type;
 
 	drawable->surface_id = surface;		/* Only primary for now */
@@ -91,14 +109,23 @@ make_drawable(struct qxl_device *qdev, int surface, uint8_t type,
 		drawable->bbox = *rect;
 
 	drawable->mm_time = qdev->rom->mm_clock;
-	qxl_release_unmap(qdev, *release, &drawable->release_info);
+	qxl_release_unmap(qdev, release, &drawable->release_info);
 	return 0;
 }
 
-static int qxl_palette_create_1bit(struct qxl_bo **palette_bo,
+static int alloc_palette_object(struct qxl_device *qdev,
+				struct qxl_release *release,
+				struct qxl_bo **palette_bo)
+{
+	return qxl_alloc_bo_reserved(qdev, release,
+				     sizeof(struct qxl_palette) + sizeof(uint32_t) * 2,
+				     palette_bo);
+}
+
+static int qxl_palette_create_1bit(struct qxl_bo *palette_bo,
+				   struct qxl_release *release,
 				   const struct qxl_fb_image *qxl_fb_image)
 {
-	struct qxl_device *qdev = qxl_fb_image->qdev;
 	const struct fb_image *fb_image = &qxl_fb_image->fb_image;
 	uint32_t visual = qxl_fb_image->visual;
 	const uint32_t *pseudo_palette = qxl_fb_image->pseudo_palette;
@@ -108,12 +135,7 @@ static int qxl_palette_create_1bit(struct qxl_bo **palette_bo,
 	static uint64_t unique; /* we make no attempt to actually set this
 				 * correctly globaly, since that would require
 				 * tracking all of our palettes. */
-
-	ret = qxl_alloc_bo_reserved(qdev,
-				    sizeof(struct qxl_palette) + sizeof(uint32_t) * 2,
-				    palette_bo);
-
-	ret = qxl_bo_kmap(*palette_bo, (void **)&pal);
+	ret = qxl_bo_kmap(palette_bo, (void **)&pal);
 	pal->num_ents = 2;
 	pal->unique = unique++;
 	if (visual == FB_VISUAL_TRUECOLOR || visual == FB_VISUAL_DIRECTCOLOR) {
@@ -126,7 +148,7 @@ static int qxl_palette_create_1bit(struct qxl_bo **palette_bo,
 	}
 	pal->ents[0] = bgcolor;
 	pal->ents[1] = fgcolor;
-	qxl_bo_kunmap(*palette_bo);
+	qxl_bo_kunmap(palette_bo);
 	return 0;
 }
 
@@ -144,44 +166,63 @@ void qxl_draw_opaque_fb(const struct qxl_fb_image *qxl_fb_image,
 	const char *src = fb_image->data;
 	int depth = fb_image->depth;
 	struct qxl_release *release;
-	struct qxl_bo *image_bo;
 	struct qxl_image *image;
 	int ret;
-
+	struct qxl_drm_image *dimage;
+	struct qxl_bo *palette_bo = NULL;
 	if (stride == 0)
 		stride = depth * width / 8;
 
+	ret = alloc_drawable(qdev, &release);
+	if (ret)
+		return;
+
+	ret = qxl_image_alloc_objects(qdev, release,
+				      &dimage,
+				      height, stride);
+	if (ret)
+		goto out_free_drawable;
+
+	if (depth == 1) {
+		ret = alloc_palette_object(qdev, release, &palette_bo);
+		if (ret)
+			goto out_free_image;
+	}
+
+	/* do a reservation run over all the objects we just allocated */
+	ret = qxl_release_reserve_list(release, true);
+	if (ret)
+		goto out_free_palette;
+
 	rect.left = x;
 	rect.right = x + width;
 	rect.top = y;
 	rect.bottom = y + height;
 
-	ret = make_drawable(qdev, 0, QXL_DRAW_COPY, &rect, &release);
-	if (ret)
-		return;
+	ret = make_drawable(qdev, 0, QXL_DRAW_COPY, &rect, release);
+	if (ret) {
+		qxl_release_backoff_reserve_list(release);
+		goto out_free_palette;
+	}
 
-	ret = qxl_image_create(qdev, release, &image_bo,
-			       (const uint8_t *)src, 0, 0,
-			       width, height, depth, stride);
+	ret = qxl_image_init(qdev, release, dimage,
+			     (const uint8_t *)src, 0, 0,
+			     width, height, depth, stride);
 	if (ret) {
-		qxl_release_unreserve(qdev, release);
+		qxl_release_backoff_reserve_list(release);
 		qxl_release_free(qdev, release);
 		return;
 	}
 
 	if (depth == 1) {
-		struct qxl_bo *palette_bo;
 		void *ptr;
-		ret = qxl_palette_create_1bit(&palette_bo, qxl_fb_image);
-		qxl_release_add_res(qdev, release, palette_bo);
+		ret = qxl_palette_create_1bit(palette_bo, release, qxl_fb_image);
 
-		ptr = qxl_bo_kmap_atomic_page(qdev, image_bo, 0);
+		ptr = qxl_bo_kmap_atomic_page(qdev, dimage->bo, 0);
 		image = ptr;
 		image->u.bitmap.palette =
 			qxl_bo_physical_address(qdev, palette_bo, 0);
-		qxl_bo_kunmap_atomic_page(qdev, image_bo, ptr);
-		qxl_bo_unreserve(palette_bo);
-		qxl_bo_unref(&palette_bo);
+		qxl_bo_kunmap_atomic_page(qdev, dimage->bo, ptr);
 	}
 
 	drawable = (struct qxl_drawable *)qxl_release_map(qdev, release);
@@ -199,16 +240,20 @@ void qxl_draw_opaque_fb(const struct qxl_fb_image *qxl_fb_image,
 	drawable->u.copy.mask.bitmap = 0;
 
 	drawable->u.copy.src_bitmap =
-		qxl_bo_physical_address(qdev, image_bo, 0);
+		qxl_bo_physical_address(qdev, dimage->bo, 0);
 	qxl_release_unmap(qdev, release, &drawable->release_info);
 
-	qxl_release_add_res(qdev, release, image_bo);
-	qxl_bo_unreserve(image_bo);
-	qxl_bo_unref(&image_bo);
-
-	qxl_fence_releaseable(qdev, release);
 	qxl_push_command_ring_release(qdev, release, QXL_CMD_DRAW, false);
-	qxl_release_unreserve(qdev, release);
+	qxl_release_fence_buffer_objects(release);
+
+out_free_palette:
+	if (palette_bo)
+		qxl_bo_unref(&palette_bo);
+out_free_image:
+	qxl_image_free_objects(qdev, dimage);
+out_free_drawable:
+	if (ret)
+		free_drawable(qdev, release);
 }
 
 /* push a draw command using the given clipping rectangles as
@@ -243,10 +288,14 @@ void qxl_draw_dirty_fb(struct qxl_device *qdev,
 	int depth = qxl_fb->base.bits_per_pixel;
 	uint8_t *surface_base;
 	struct qxl_release *release;
-	struct qxl_bo *image_bo;
 	struct qxl_bo *clips_bo;
+	struct qxl_drm_image *dimage;
 	int ret;
 
+	ret = alloc_drawable(qdev, &release);
+	if (ret)
+		return;
+
 	left = clips->x1;
 	right = clips->x2;
 	top = clips->y1;
@@ -263,36 +312,52 @@ void qxl_draw_dirty_fb(struct qxl_device *qdev,
 
 	width = right - left;
 	height = bottom - top;
+
+	ret = alloc_clips(qdev, release, num_clips, &clips_bo);
+	if (ret)
+		goto out_free_drawable;
+
+	ret = qxl_image_alloc_objects(qdev, release,
+				      &dimage,
+				      height, stride);
+	if (ret)
+		goto out_free_clips;
+
+	/* do a reservation run over all the objects we just allocated */
+	ret = qxl_release_reserve_list(release, true);
+	if (ret)
+		goto out_free_image;
+
 	drawable_rect.left = left;
 	drawable_rect.right = right;
 	drawable_rect.top = top;
 	drawable_rect.bottom = bottom;
+
 	ret = make_drawable(qdev, 0, QXL_DRAW_COPY, &drawable_rect,
-			    &release);
+			    release);
 	if (ret)
-		return;
+		goto out_release_backoff;
 
 	ret = qxl_bo_kmap(bo, (void **)&surface_base);
 	if (ret)
-		goto out_unref;
+		goto out_release_backoff;
 
-	ret = qxl_image_create(qdev, release, &image_bo, surface_base,
-			       left, top, width, height, depth, stride);
+
+	ret = qxl_image_init(qdev, release, dimage, surface_base,
+			     left, top, width, height, depth, stride);
 	qxl_bo_kunmap(bo);
 	if (ret)
-		goto out_unref;
+		goto out_release_backoff;
+
+	rects = drawable_set_clipping(qdev, drawable, num_clips, clips_bo);
+	if (!rects)
+		goto out_release_backoff;
 
-	rects = drawable_set_clipping(qdev, drawable, num_clips, &clips_bo, release);
-	if (!rects) {
-		qxl_bo_unref(&image_bo);
-		goto out_unref;
-	}
 	drawable = (struct qxl_drawable *)qxl_release_map(qdev, release);
 
 	drawable->clip.type = SPICE_CLIP_TYPE_RECTS;
 	drawable->clip.data = qxl_bo_physical_address(qdev,
 						      clips_bo, 0);
-	qxl_release_add_res(qdev, release, clips_bo);
 
 	drawable->u.copy.src_area.top = 0;
 	drawable->u.copy.src_area.bottom = height;
@@ -306,11 +371,9 @@ void qxl_draw_dirty_fb(struct qxl_device *qdev,
 	drawable->u.copy.mask.pos.y = 0;
 	drawable->u.copy.mask.bitmap = 0;
 
-	drawable->u.copy.src_bitmap = qxl_bo_physical_address(qdev, image_bo, 0);
+	drawable->u.copy.src_bitmap = qxl_bo_physical_address(qdev, dimage->bo, 0);
 	qxl_release_unmap(qdev, release, &drawable->release_info);
-	qxl_release_add_res(qdev, release, image_bo);
-	qxl_bo_unreserve(image_bo);
-	qxl_bo_unref(&image_bo);
+
 	clips_ptr = clips;
 	for (i = 0; i < num_clips; i++, clips_ptr += inc) {
 		rects[i].left   = clips_ptr->x1;
@@ -319,17 +382,22 @@ void qxl_draw_dirty_fb(struct qxl_device *qdev,
 		rects[i].bottom = clips_ptr->y2;
 	}
 	qxl_bo_kunmap(clips_bo);
-	qxl_bo_unreserve(clips_bo);
-	qxl_bo_unref(&clips_bo);
 
-	qxl_fence_releaseable(qdev, release);
 	qxl_push_command_ring_release(qdev, release, QXL_CMD_DRAW, false);
-	qxl_release_unreserve(qdev, release);
-	return;
+	qxl_release_fence_buffer_objects(release);
+
+out_release_backoff:
+	if (ret)
+		qxl_release_backoff_reserve_list(release);
+out_free_image:
+	qxl_image_free_objects(qdev, dimage);
+out_free_clips:
+	qxl_bo_unref(&clips_bo);
+out_free_drawable:
+	/* only free drawable on error */
+	if (ret)
+		free_drawable(qdev, release);
 
-out_unref:
-	qxl_release_unreserve(qdev, release);
-	qxl_release_free(qdev, release);
 }
 
 void qxl_draw_copyarea(struct qxl_device *qdev,
@@ -342,22 +410,36 @@ void qxl_draw_copyarea(struct qxl_device *qdev,
 	struct qxl_release *release;
 	int ret;
 
+	ret = alloc_drawable(qdev, &release);
+	if (ret)
+		return;
+
+	/* do a reservation run over all the objects we just allocated */
+	ret = qxl_release_reserve_list(release, true);
+	if (ret)
+		goto out_free_release;
+
 	rect.left = dx;
 	rect.top = dy;
 	rect.right = dx + width;
 	rect.bottom = dy + height;
-	ret = make_drawable(qdev, 0, QXL_COPY_BITS, &rect, &release);
-	if (ret)
-		return;
+	ret = make_drawable(qdev, 0, QXL_COPY_BITS, &rect, release);
+	if (ret) {
+		qxl_release_backoff_reserve_list(release);
+		goto out_free_release;
+	}
 
 	drawable = (struct qxl_drawable *)qxl_release_map(qdev, release);
 	drawable->u.copy_bits.src_pos.x = sx;
 	drawable->u.copy_bits.src_pos.y = sy;
-
 	qxl_release_unmap(qdev, release, &drawable->release_info);
-	qxl_fence_releaseable(qdev, release);
+
 	qxl_push_command_ring_release(qdev, release, QXL_CMD_DRAW, false);
-	qxl_release_unreserve(qdev, release);
+	qxl_release_fence_buffer_objects(release);
+
+out_free_release:
+	if (ret)
+		free_drawable(qdev, release);
 }
 
 void qxl_draw_fill(struct qxl_draw_fill *qxl_draw_fill_rec)
@@ -370,10 +452,21 @@ void qxl_draw_fill(struct qxl_draw_fill *qxl_draw_fill_rec)
 	struct qxl_release *release;
 	int ret;
 
-	ret = make_drawable(qdev, 0, QXL_DRAW_FILL, &rect, &release);
+	ret = alloc_drawable(qdev, &release);
 	if (ret)
 		return;
 
+	/* do a reservation run over all the objects we just allocated */
+	ret = qxl_release_reserve_list(release, true);
+	if (ret)
+		goto out_free_release;
+
+	ret = make_drawable(qdev, 0, QXL_DRAW_FILL, &rect, release);
+	if (ret) {
+		qxl_release_backoff_reserve_list(release);
+		goto out_free_release;
+	}
+
 	drawable = (struct qxl_drawable *)qxl_release_map(qdev, release);
 	drawable->u.fill.brush.type = SPICE_BRUSH_TYPE_SOLID;
 	drawable->u.fill.brush.u.color = color;
@@ -384,7 +477,11 @@ void qxl_draw_fill(struct qxl_draw_fill *qxl_draw_fill_rec)
 	drawable->u.fill.mask.bitmap = 0;
 
 	qxl_release_unmap(qdev, release, &drawable->release_info);
-	qxl_fence_releaseable(qdev, release);
+
 	qxl_push_command_ring_release(qdev, release, QXL_CMD_DRAW, false);
-	qxl_release_unreserve(qdev, release);
+	qxl_release_fence_buffer_objects(release);
+
+out_free_release:
+	if (ret)
+		free_drawable(qdev, release);
 }