1 files changed, 191 insertions, 112 deletions

diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
index 7047ca025787..492acce0516f 100644
--- a/drivers/gpu/drm/drm_rect.c
+++ b/drivers/gpu/drm/drm_rect.c
@@ -24,7 +24,9 @@
 #include <linux/errno.h>
 #include <linux/export.h>
 #include <linux/kernel.h>
-#include <drm/drmP.h>
+
+#include <drm/drm_mode.h>
+#include <drm/drm_print.h>
 #include <drm/drm_rect.h>
 
 /**
@@ -50,49 +52,81 @@ bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
 }
 EXPORT_SYMBOL(drm_rect_intersect);
 
+static u32 clip_scaled(int src, int dst, int *clip)
+{
+	u64 tmp;
+
+	if (dst == 0)
+		return 0;
+
+	/* Only clip what we have. Keeps the result bounded. */
+	*clip = min(*clip, dst);
+
+	tmp = mul_u32_u32(src, dst - *clip);
+
+	/*
+	 * Round toward 1.0 when clipping so that we don't accidentally
+	 * change upscaling to downscaling or vice versa.
+	 */
+	if (src < (dst << 16))
+		return DIV_ROUND_UP_ULL(tmp, dst);
+	else
+		return DIV_ROUND_DOWN_ULL(tmp, dst);
+}
+
 /**
  * drm_rect_clip_scaled - perform a scaled clip operation
  * @src: source window rectangle
  * @dst: destination window rectangle
  * @clip: clip rectangle
- * @hscale: horizontal scaling factor
- * @vscale: vertical scaling factor
  *
- * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
- * same amounts multiplied by @hscale and @vscale.
+ * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by
+ * the corresponding amounts, retaining the vertical and horizontal scaling
+ * factors from @src to @dst.
  *
  * RETURNS:
  * %true if rectangle @dst is still visible after being clipped,
- * %false otherwise
+ * %false otherwise.
  */
 bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
-			  const struct drm_rect *clip,
-			  int hscale, int vscale)
+			  const struct drm_rect *clip)
 {
 	int diff;
 
 	diff = clip->x1 - dst->x1;
 	if (diff > 0) {
-		int64_t tmp = src->x1 + (int64_t) diff * hscale;
-		src->x1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+		u32 new_src_w = clip_scaled(drm_rect_width(src),
+					    drm_rect_width(dst), &diff);
+
+		src->x1 = src->x2 - new_src_w;
+		dst->x1 += diff;
 	}
 	diff = clip->y1 - dst->y1;
 	if (diff > 0) {
-		int64_t tmp = src->y1 + (int64_t) diff * vscale;
-		src->y1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+		u32 new_src_h = clip_scaled(drm_rect_height(src),
+					    drm_rect_height(dst), &diff);
+
+		src->y1 = src->y2 - new_src_h;
+		dst->y1 += diff;
 	}
 	diff = dst->x2 - clip->x2;
 	if (diff > 0) {
-		int64_t tmp = src->x2 - (int64_t) diff * hscale;
-		src->x2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+		u32 new_src_w = clip_scaled(drm_rect_width(src),
+					    drm_rect_width(dst), &diff);
+
+		src->x2 = src->x1 + new_src_w;
+		dst->x2 -= diff;
 	}
 	diff = dst->y2 - clip->y2;
 	if (diff > 0) {
-		int64_t tmp = src->y2 - (int64_t) diff * vscale;
-		src->y2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
+		u32 new_src_h = clip_scaled(drm_rect_height(src),
+					    drm_rect_height(dst), &diff);
+
+		src->y2 = src->y1 + new_src_h;
+		dst->y2 -= diff;
 	}
 
-	return drm_rect_intersect(dst, clip);
+	return drm_rect_visible(dst);
 }
 EXPORT_SYMBOL(drm_rect_clip_scaled);
 
@@ -100,13 +134,16 @@ static int drm_calc_scale(int src, int dst)
 {
 	int scale = 0;
 
-	if (src < 0 || dst < 0)
+	if (WARN_ON(src < 0 || dst < 0))
 		return -EINVAL;
 
 	if (dst == 0)
 		return 0;
 
-	scale = src / dst;
+	if (src > (dst << 16))
+		return DIV_ROUND_UP(src, dst);
+	else
+		scale = src / dst;
 
 	return scale;
 }
@@ -121,6 +158,10 @@ static int drm_calc_scale(int src, int dst)
  * Calculate the horizontal scaling factor as
  * (@src width) / (@dst width).
  *
+ * If the scale is below 1 << 16, round down. If the scale is above
+ * 1 << 16, round up. This will calculate the scale with the most
+ * pessimistic limit calculation.
+ *
  * RETURNS:
  * The horizontal scaling factor, or errno of out of limits.
  */
@@ -152,6 +193,10 @@ EXPORT_SYMBOL(drm_rect_calc_hscale);
  * Calculate the vertical scaling factor as
  * (@src height) / (@dst height).
  *
+ * If the scale is below 1 << 16, round down. If the scale is above
+ * 1 << 16, round up. This will calculate the scale with the most
+ * pessimistic limit calculation.
+ *
  * RETURNS:
  * The vertical scaling factor, or errno of out of limits.
  */
@@ -174,122 +219,156 @@ int drm_rect_calc_vscale(const struct drm_rect *src,
 EXPORT_SYMBOL(drm_rect_calc_vscale);
 
 /**
- * drm_calc_hscale_relaxed - calculate the horizontal scaling factor
- * @src: source window rectangle
- * @dst: destination window rectangle
- * @min_hscale: minimum allowed horizontal scaling factor
- * @max_hscale: maximum allowed horizontal scaling factor
- *
- * Calculate the horizontal scaling factor as
- * (@src width) / (@dst width).
+ * drm_rect_debug_print - print the rectangle information
+ * @prefix: prefix string
+ * @r: rectangle to print
+ * @fixed_point: rectangle is in 16.16 fixed point format
+ */
+void drm_rect_debug_print(const char *prefix, const struct drm_rect *r, bool fixed_point)
+{
+	if (fixed_point)
+		DRM_DEBUG_KMS("%s" DRM_RECT_FP_FMT "\n", prefix, DRM_RECT_FP_ARG(r));
+	else
+		DRM_DEBUG_KMS("%s" DRM_RECT_FMT "\n", prefix, DRM_RECT_ARG(r));
+}
+EXPORT_SYMBOL(drm_rect_debug_print);
+
+/**
+ * drm_rect_rotate - Rotate the rectangle
+ * @r: rectangle to be rotated
+ * @width: Width of the coordinate space
+ * @height: Height of the coordinate space
+ * @rotation: Transformation to be applied
  *
- * If the calculated scaling factor is below @min_vscale,
- * decrease the height of rectangle @dst to compensate.
+ * Apply @rotation to the coordinates of rectangle @r.
  *
- * If the calculated scaling factor is above @max_vscale,
- * decrease the height of rectangle @src to compensate.
+ * @width and @height combined with @rotation define
+ * the location of the new origin.
  *
- * RETURNS:
- * The horizontal scaling factor.
+ * @width correcsponds to the horizontal and @height
+ * to the vertical axis of the untransformed coordinate
+ * space.
  */
-int drm_rect_calc_hscale_relaxed(struct drm_rect *src,
-				 struct drm_rect *dst,
-				 int min_hscale, int max_hscale)
+void drm_rect_rotate(struct drm_rect *r,
+		     int width, int height,
+		     unsigned int rotation)
 {
-	int src_w = drm_rect_width(src);
-	int dst_w = drm_rect_width(dst);
-	int hscale = drm_calc_scale(src_w, dst_w);
+	struct drm_rect tmp;
 
-	if (hscale < 0 || dst_w == 0)
-		return hscale;
+	if (rotation & (DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y)) {
+		tmp = *r;
 
-	if (hscale < min_hscale) {
-		int max_dst_w = src_w / min_hscale;
+		if (rotation & DRM_MODE_REFLECT_X) {
+			r->x1 = width - tmp.x2;
+			r->x2 = width - tmp.x1;
+		}
 
-		drm_rect_adjust_size(dst, max_dst_w - dst_w, 0);
-
-		return min_hscale;
+		if (rotation & DRM_MODE_REFLECT_Y) {
+			r->y1 = height - tmp.y2;
+			r->y2 = height - tmp.y1;
+		}
 	}
 
-	if (hscale > max_hscale) {
-		int max_src_w = dst_w * max_hscale;
-
-		drm_rect_adjust_size(src, max_src_w - src_w, 0);
-
-		return max_hscale;
+	switch (rotation & DRM_MODE_ROTATE_MASK) {
+	case DRM_MODE_ROTATE_0:
+		break;
+	case DRM_MODE_ROTATE_90:
+		tmp = *r;
+		r->x1 = tmp.y1;
+		r->x2 = tmp.y2;
+		r->y1 = width - tmp.x2;
+		r->y2 = width - tmp.x1;
+		break;
+	case DRM_MODE_ROTATE_180:
+		tmp = *r;
+		r->x1 = width - tmp.x2;
+		r->x2 = width - tmp.x1;
+		r->y1 = height - tmp.y2;
+		r->y2 = height - tmp.y1;
+		break;
+	case DRM_MODE_ROTATE_270:
+		tmp = *r;
+		r->x1 = height - tmp.y2;
+		r->x2 = height - tmp.y1;
+		r->y1 = tmp.x1;
+		r->y2 = tmp.x2;
+		break;
+	default:
+		break;
 	}
-
-	return hscale;
 }
-EXPORT_SYMBOL(drm_rect_calc_hscale_relaxed);
+EXPORT_SYMBOL(drm_rect_rotate);
 
 /**
- * drm_rect_calc_vscale_relaxed - calculate the vertical scaling factor
- * @src: source window rectangle
- * @dst: destination window rectangle
- * @min_vscale: minimum allowed vertical scaling factor
- * @max_vscale: maximum allowed vertical scaling factor
+ * drm_rect_rotate_inv - Inverse rotate the rectangle
+ * @r: rectangle to be rotated
+ * @width: Width of the coordinate space
+ * @height: Height of the coordinate space
+ * @rotation: Transformation whose inverse is to be applied
  *
- * Calculate the vertical scaling factor as
- * (@src height) / (@dst height).
+ * Apply the inverse of @rotation to the coordinates
+ * of rectangle @r.
  *
- * If the calculated scaling factor is below @min_vscale,
- * decrease the height of rectangle @dst to compensate.
+ * @width and @height combined with @rotation define
+ * the location of the new origin.
  *
- * If the calculated scaling factor is above @max_vscale,
- * decrease the height of rectangle @src to compensate.
+ * @width correcsponds to the horizontal and @height
+ * to the vertical axis of the original untransformed
+ * coordinate space, so that you never have to flip
+ * them when doing a rotatation and its inverse.
+ * That is, if you do ::
  *
- * RETURNS:
- * The vertical scaling factor.
+ *     drm_rect_rotate(&r, width, height, rotation);
+ *     drm_rect_rotate_inv(&r, width, height, rotation);
+ *
+ * you will always get back the original rectangle.
  */
-int drm_rect_calc_vscale_relaxed(struct drm_rect *src,
-				 struct drm_rect *dst,
-				 int min_vscale, int max_vscale)
+void drm_rect_rotate_inv(struct drm_rect *r,
+			 int width, int height,
+			 unsigned int rotation)
 {
-	int src_h = drm_rect_height(src);
-	int dst_h = drm_rect_height(dst);
-	int vscale = drm_calc_scale(src_h, dst_h);
-
-	if (vscale < 0 || dst_h == 0)
-		return vscale;
-
-	if (vscale < min_vscale) {
-		int max_dst_h = src_h / min_vscale;
-
-		drm_rect_adjust_size(dst, 0, max_dst_h - dst_h);
-
-		return min_vscale;
+	struct drm_rect tmp;
+
+	switch (rotation & DRM_MODE_ROTATE_MASK) {
+	case DRM_MODE_ROTATE_0:
+		break;
+	case DRM_MODE_ROTATE_90:
+		tmp = *r;
+		r->x1 = width - tmp.y2;
+		r->x2 = width - tmp.y1;
+		r->y1 = tmp.x1;
+		r->y2 = tmp.x2;
+		break;
+	case DRM_MODE_ROTATE_180:
+		tmp = *r;
+		r->x1 = width - tmp.x2;
+		r->x2 = width - tmp.x1;
+		r->y1 = height - tmp.y2;
+		r->y2 = height - tmp.y1;
+		break;
+	case DRM_MODE_ROTATE_270:
+		tmp = *r;
+		r->x1 = tmp.y1;
+		r->x2 = tmp.y2;
+		r->y1 = height - tmp.x2;
+		r->y2 = height - tmp.x1;
+		break;
+	default:
+		break;
 	}
 
-	if (vscale > max_vscale) {
-		int max_src_h = dst_h * max_vscale;
+	if (rotation & (DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y)) {
+		tmp = *r;
 
-		drm_rect_adjust_size(src, 0, max_src_h - src_h);
+		if (rotation & DRM_MODE_REFLECT_X) {
+			r->x1 = width - tmp.x2;
+			r->x2 = width - tmp.x1;
+		}
 
-		return max_vscale;
+		if (rotation & DRM_MODE_REFLECT_Y) {
+			r->y1 = height - tmp.y2;
+			r->y2 = height - tmp.y1;
+		}
 	}
-
-	return vscale;
 }
-EXPORT_SYMBOL(drm_rect_calc_vscale_relaxed);
-
-/**
- * drm_rect_debug_print - print the rectangle information
- * @r: rectangle to print
- * @fixed_point: rectangle is in 16.16 fixed point format
- */
-void drm_rect_debug_print(const struct drm_rect *r, bool fixed_point)
-{
-	int w = drm_rect_width(r);
-	int h = drm_rect_height(r);
-
-	if (fixed_point)
-		DRM_DEBUG_KMS("%d.%06ux%d.%06u%+d.%06u%+d.%06u\n",
-			      w >> 16, ((w & 0xffff) * 15625) >> 10,
-			      h >> 16, ((h & 0xffff) * 15625) >> 10,
-			      r->x1 >> 16, ((r->x1 & 0xffff) * 15625) >> 10,
-			      r->y1 >> 16, ((r->y1 & 0xffff) * 15625) >> 10);
-	else
-		DRM_DEBUG_KMS("%dx%d%+d%+d\n", w, h, r->x1, r->y1);
-}
-EXPORT_SYMBOL(drm_rect_debug_print);
+EXPORT_SYMBOL(drm_rect_rotate_inv);