2 files changed, 98 insertions, 1 deletions

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);