File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/video/fbdev/c2p_planar.c b/drivers/video/fbdev/c2p_planar.c
new file mode 100644
index 0000000..ec7ac85
--- /dev/null
+++ b/drivers/video/fbdev/c2p_planar.c
@@ -0,0 +1,156 @@
+/*
+ *  Fast C2P (Chunky-to-Planar) Conversion
+ *
+ *  Copyright (C) 2003-2008 Geert Uytterhoeven
+ *
+ *  This file is subject to the terms and conditions of the GNU General Public
+ *  License. See the file COPYING in the main directory of this archive
+ *  for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+
+#include <asm/unaligned.h>
+
+#include "c2p.h"
+#include "c2p_core.h"
+
+
+    /*
+     *  Perform a full C2P step on 32 8-bit pixels, stored in 8 32-bit words
+     *  containing
+     *    - 32 8-bit chunky pixels on input
+     *    - permutated planar data (1 plane per 32-bit word) on output
+     */
+
+static void c2p_32x8(u32 d[8])
+{
+	transp8(d, 16, 4);
+	transp8(d, 8, 2);
+	transp8(d, 4, 1);
+	transp8(d, 2, 4);
+	transp8(d, 1, 2);
+}
+
+
+    /*
+     *  Array containing the permutation indices of the planar data after c2p
+     */
+
+static const int perm_c2p_32x8[8] = { 7, 5, 3, 1, 6, 4, 2, 0 };
+
+
+    /*
+     *  Store a full block of planar data after c2p conversion
+     */
+
+static inline void store_planar(void *dst, u32 dst_inc, u32 bpp, u32 d[8])
+{
+	int i;
+
+	for (i = 0; i < bpp; i++, dst += dst_inc)
+		put_unaligned_be32(d[perm_c2p_32x8[i]], dst);
+}
+
+
+    /*
+     *  Store a partial block of planar data after c2p conversion
+     */
+
+static inline void store_planar_masked(void *dst, u32 dst_inc, u32 bpp,
+				       u32 d[8], u32 mask)
+{
+	int i;
+
+	for (i = 0; i < bpp; i++, dst += dst_inc)
+		put_unaligned_be32(comp(d[perm_c2p_32x8[i]],
+					get_unaligned_be32(dst), mask),
+				   dst);
+}
+
+
+    /*
+     *  c2p_planar - Copy 8-bit chunky image data to a planar frame buffer
+     *  @dst: Starting address of the planar frame buffer
+     *  @dx: Horizontal destination offset (in pixels)
+     *  @dy: Vertical destination offset (in pixels)
+     *  @width: Image width (in pixels)
+     *  @height: Image height (in pixels)
+     *  @dst_nextline: Frame buffer offset to the next line (in bytes)
+     *  @dst_nextplane: Frame buffer offset to the next plane (in bytes)
+     *  @src_nextline: Image offset to the next line (in bytes)
+     *  @bpp: Bits per pixel of the planar frame buffer (1-8)
+     */
+
+void c2p_planar(void *dst, const void *src, u32 dx, u32 dy, u32 width,
+		u32 height, u32 dst_nextline, u32 dst_nextplane,
+		u32 src_nextline, u32 bpp)
+{
+	union {
+		u8 pixels[32];
+		u32 words[8];
+	} d;
+	u32 dst_idx, first, last, w;
+	const u8 *c;
+	void *p;
+
+	dst += dy*dst_nextline+(dx & ~31);
+	dst_idx = dx % 32;
+	first = 0xffffffffU >> dst_idx;
+	last = ~(0xffffffffU >> ((dst_idx+width) % 32));
+	while (height--) {
+		c = src;
+		p = dst;
+		w = width;
+		if (dst_idx+width <= 32) {
+			/* Single destination word */
+			first &= last;
+			memset(d.pixels, 0, sizeof(d));
+			memcpy(d.pixels+dst_idx, c, width);
+			c += width;
+			c2p_32x8(d.words);
+			store_planar_masked(p, dst_nextplane, bpp, d.words,
+					    first);
+			p += 4;
+		} else {
+			/* Multiple destination words */
+			w = width;
+			/* Leading bits */
+			if (dst_idx) {
+				w = 32 - dst_idx;
+				memset(d.pixels, 0, dst_idx);
+				memcpy(d.pixels+dst_idx, c, w);
+				c += w;
+				c2p_32x8(d.words);
+				store_planar_masked(p, dst_nextplane, bpp,
+						    d.words, first);
+				p += 4;
+				w = width-w;
+			}
+			/* Main chunk */
+			while (w >= 32) {
+				memcpy(d.pixels, c, 32);
+				c += 32;
+				c2p_32x8(d.words);
+				store_planar(p, dst_nextplane, bpp, d.words);
+				p += 4;
+				w -= 32;
+			}
+			/* Trailing bits */
+			w %= 32;
+			if (w > 0) {
+				memcpy(d.pixels, c, w);
+				memset(d.pixels+w, 0, 32-w);
+				c2p_32x8(d.words);
+				store_planar_masked(p, dst_nextplane, bpp,
+						    d.words, last);
+			}
+		}
+		src += src_nextline;
+		dst += dst_nextline;
+	}
+}
+EXPORT_SYMBOL_GPL(c2p_planar);
+
+MODULE_LICENSE("GPL");