4 files changed, 232 insertions, 1 deletions

diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
index f9df3b872c16..7c7af25b330c 100644
--- a/Documentation/DocBook/drm.tmpl
+++ b/Documentation/DocBook/drm.tmpl
@@ -1653,6 +1653,8 @@ void intel_crt_init(struct drm_device *dev)
     <sect2>
       <title>KMS API Functions</title>
 !Edrivers/gpu/drm/drm_crtc.c
+!Edrivers/gpu/drm/drm_rect.c
+!Finclude/drm/drm_rect.h
     </sect2>
   </sect1>
 
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 0d59b24f8d23..8f94018852a6 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -12,7 +12,8 @@ drm-y       :=	drm_auth.o drm_buffer.o drm_bufs.o drm_cache.o \
                 drm_platform.o drm_sysfs.o drm_hashtab.o drm_mm.o \
                 drm_crtc.o drm_modes.o drm_edid.o \
                 drm_info.o drm_debugfs.o drm_encoder_slave.o \
-                drm_trace_points.o drm_global.o drm_prime.o
+                drm_trace_points.o drm_global.o drm_prime.o \
+                drm_rect.o
 
 drm-$(CONFIG_COMPAT) += drm_ioc32.o
 drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o
diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
new file mode 100644
index 000000000000..22091ecdbff4
--- /dev/null
+++ b/drivers/gpu/drm/drm_rect.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2011-2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <drm/drm_rect.h>
+
+/**
+ * drm_rect_intersect - intersect two rectangles
+ * @r1: first rectangle
+ * @r2: second rectangle
+ *
+ * Calculate the intersection of rectangles @r1 and @r2.
+ * @r1 will be overwritten with the intersection.
+ *
+ * RETURNS:
+ * %true if rectangle @r1 is still visible after the operation,
+ * %false otherwise.
+ */
+bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
+{
+        r1->x1 = max(r1->x1, r2->x1);
+        r1->y1 = max(r1->y1, r2->y1);
+        r1->x2 = min(r1->x2, r2->x2);
+        r1->y2 = min(r1->y2, r2->y2);
+
+        return drm_rect_visible(r1);
+}
+EXPORT_SYMBOL(drm_rect_intersect);
+
+/**
+ * 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.
+ *
+ * RETURNS:
+ * %true if rectangle @dst is still visible after being clipped,
+ * %false otherwise
+ */
+bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
+                          const struct drm_rect *clip,
+                          int hscale, int vscale)
+{
+        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);
+        }
+        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);
+        }
+        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);
+        }
+        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);
+        }
+
+        return drm_rect_intersect(dst, clip);
+}
+EXPORT_SYMBOL(drm_rect_clip_scaled);
diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h
new file mode 100644
index 000000000000..2b7278c1bc42
--- /dev/null
+++ b/include/drm/drm_rect.h
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2011-2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef DRM_RECT_H
+#define DRM_RECT_H
+
+/**
+ * drm_rect - two dimensional rectangle
+ * @x1: horizontal starting coordinate (inclusive)
+ * @x2: horizontal ending coordinate (exclusive)
+ * @y1: vertical starting coordinate (inclusive)
+ * @y2: vertical ending coordinate (exclusive)
+ */
+struct drm_rect {
+        int x1, y1, x2, y2;
+};
+
+/**
+ * drm_rect_adjust_size - adjust the size of the rectangle
+ * @r: rectangle to be adjusted
+ * @dw: horizontal adjustment
+ * @dh: vertical adjustment
+ *
+ * Change the size of rectangle @r by @dw in the horizontal direction,
+ * and by @dh in the vertical direction, while keeping the center
+ * of @r stationary.
+ *
+ * Positive @dw and @dh increase the size, negative values decrease it.
+ */
+static inline void drm_rect_adjust_size(struct drm_rect *r, int dw, int dh)
+{
+        r->x1 -= dw >> 1;
+        r->y1 -= dh >> 1;
+        r->x2 += (dw + 1) >> 1;
+        r->y2 += (dh + 1) >> 1;
+}
+
+/**
+ * drm_rect_translate - translate the rectangle
+ * @r: rectangle to be tranlated
+ * @dx: horizontal translation
+ * @dy: vertical translation
+ *
+ * Move rectangle @r by @dx in the horizontal direction,
+ * and by @dy in the vertical direction.
+ */
+static inline void drm_rect_translate(struct drm_rect *r, int dx, int dy)
+{
+        r->x1 += dx;
+        r->y1 += dy;
+        r->x2 += dx;
+        r->y2 += dy;
+}
+
+/**
+ * drm_rect_downscale - downscale a rectangle
+ * @r: rectangle to be downscaled
+ * @horz: horizontal downscale factor
+ * @vert: vertical downscale factor
+ *
+ * Divide the coordinates of rectangle @r by @horz and @vert.
+ */
+static inline void drm_rect_downscale(struct drm_rect *r, int horz, int vert)
+{
+        r->x1 /= horz;
+        r->y1 /= vert;
+        r->x2 /= horz;
+        r->y2 /= vert;
+}
+
+/**
+ * drm_rect_width - determine the rectangle width
+ * @r: rectangle whose width is returned
+ *
+ * RETURNS:
+ * The width of the rectangle.
+ */
+static inline int drm_rect_width(const struct drm_rect *r)
+{
+        return r->x2 - r->x1;
+}
+
+/**
+ * drm_rect_height - determine the rectangle height
+ * @r: rectangle whose height is returned
+ *
+ * RETURNS:
+ * The height of the rectangle.
+ */
+static inline int drm_rect_height(const struct drm_rect *r)
+{
+        return r->y2 - r->y1;
+}
+
+/**
+ * drm_rect_visible - determine if the the rectangle is visible
+ * @r: rectangle whose visibility is returned
+ *
+ * RETURNS:
+ * %true if the rectangle is visible, %false otherwise.
+ */
+static inline bool drm_rect_visible(const struct drm_rect *r)
+{
+        return drm_rect_width(r) > 0 && drm_rect_height(r) > 0;
+}
+
+bool drm_rect_intersect(struct drm_rect *r, const struct drm_rect *clip);
+bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
+                          const struct drm_rect *clip,
+                          int hscale, int vscale);
+
+#endif