m68k: Atari fb revival

Update the atari fb to 2.6 by Michael Schmitz,
Reformatting and rewrite of bit plane functions by Roman Zippel,
A few more fixes by Geert Uytterhoeven.

Signed-off-by: Michael Schmitz <schmitz@debian.org>
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 400 insertions, 0 deletions

diff --git a/drivers/video/atafb_utils.h b/drivers/video/atafb_utils.h
new file mode 100644
index 0000000..ac9e19d
--- /dev/null
+++ b/drivers/video/atafb_utils.h
@@ -0,0 +1,400 @@
+#ifndef _VIDEO_ATAFB_UTILS_H
+#define _VIDEO_ATAFB_UTILS_H
+
+/* ================================================================= */
+/*                      Utility Assembler Functions                  */
+/* ================================================================= */
+
+/* ====================================================================== */
+
+/* Those of a delicate disposition might like to skip the next couple of
+ * pages.
+ *
+ * These functions are drop in replacements for memmove and
+ * memset(_, 0, _). However their five instances add at least a kilobyte
+ * to the object file. You have been warned.
+ *
+ * Not a great fan of assembler for the sake of it, but I think
+ * that these routines are at least 10 times faster than their C
+ * equivalents for large blits, and that's important to the lowest level of
+ * a graphics driver. Question is whether some scheme with the blitter
+ * would be faster. I suspect not for simple text system - not much
+ * asynchrony.
+ *
+ * Code is very simple, just gruesome expansion. Basic strategy is to
+ * increase data moved/cleared at each step to 16 bytes to reduce
+ * instruction per data move overhead. movem might be faster still
+ * For more than 15 bytes, we try to align the write direction on a
+ * longword boundary to get maximum speed. This is even more gruesome.
+ * Unaligned read/write used requires 68020+ - think this is a problem?
+ *
+ * Sorry!
+ */
+
+
+/* ++roman: I've optimized Robert's original versions in some minor
+ * aspects, e.g. moveq instead of movel, let gcc choose the registers,
+ * use movem in some places...
+ * For other modes than 1 plane, lots of more such assembler functions
+ * were needed (e.g. the ones using movep or expanding color values).
+ */
+
+/* ++andreas: more optimizations:
+   subl #65536,d0 replaced by clrw d0; subql #1,d0 for dbcc
+   addal is faster than addaw
+   movep is rather expensive compared to ordinary move's
+   some functions rewritten in C for clarity, no speed loss */
+
+static inline void *fb_memclear_small(void *s, size_t count)
+{
+	if (!count)
+		return 0;
+
+	asm volatile ("\n"
+		"	lsr.l	#1,%1 ; jcc 1f ; move.b %2,-(%0)\n"
+		"1:	lsr.l	#1,%1 ; jcc 1f ; move.w %2,-(%0)\n"
+		"1:	lsr.l	#1,%1 ; jcc 1f ; move.l %2,-(%0)\n"
+		"1:	lsr.l	#1,%1 ; jcc 1f ; move.l %2,-(%0) ; move.l %2,-(%0)\n"
+		"1:"
+		: "=a" (s), "=d" (count)
+		: "d" (0), "0" ((char *)s + count), "1" (count));
+	asm volatile ("\n"
+		"	subq.l  #1,%1\n"
+		"	jcs	3f\n"
+		"	move.l	%2,%%d4; move.l %2,%%d5; move.l %2,%%d6\n"
+		"2:	movem.l	%2/%%d4/%%d5/%%d6,-(%0)\n"
+		"	dbra	%1,2b\n"
+		"3:"
+		: "=a" (s), "=d" (count)
+		: "d" (0), "0" (s), "1" (count)
+		: "d4", "d5", "d6"
+		);
+
+	return 0;
+}
+
+
+static inline void *fb_memclear(void *s, size_t count)
+{
+	if (!count)
+		return 0;
+
+	if (count < 16) {
+		asm volatile ("\n"
+			"	lsr.l	#1,%1 ; jcc 1f ; clr.b (%0)+\n"
+			"1:	lsr.l	#1,%1 ; jcc 1f ; clr.w (%0)+\n"
+			"1:	lsr.l	#1,%1 ; jcc 1f ; clr.l (%0)+\n"
+			"1:	lsr.l	#1,%1 ; jcc 1f ; clr.l (%0)+ ; clr.l (%0)+\n"
+			"1:"
+			: "=a" (s), "=d" (count)
+			: "0" (s), "1" (count));
+	} else {
+		long tmp;
+		asm volatile ("\n"
+			"	move.l	%1,%2\n"
+			"	lsr.l	#1,%2 ; jcc 1f ; clr.b (%0)+ ; subq.w #1,%1\n"
+			"	lsr.l	#1,%2 ; jcs 2f\n"  /* %0 increased=>bit 2 switched*/
+			"	clr.w	(%0)+  ; subq.w  #2,%1 ; jra 2f\n"
+			"1:	lsr.l	#1,%2 ; jcc 2f\n"
+			"	clr.w	(%0)+  ; subq.w  #2,%1\n"
+			"2:	move.w	%1,%2; lsr.l #2,%1 ; jeq 6f\n"
+			"	lsr.l	#1,%1 ; jcc 3f ; clr.l (%0)+\n"
+			"3:	lsr.l	#1,%1 ; jcc 4f ; clr.l (%0)+ ; clr.l (%0)+\n"
+			"4:	subq.l	#1,%1 ; jcs 6f\n"
+			"5:	clr.l	(%0)+; clr.l (%0)+ ; clr.l (%0)+ ; clr.l (%0)+\n"
+			"	dbra	%1,5b ; clr.w %1; subq.l #1,%1; jcc 5b\n"
+			"6:	move.w	%2,%1; btst #1,%1 ; jeq 7f ; clr.w (%0)+\n"
+			"7:	btst	#0,%1 ; jeq 8f ; clr.b (%0)+\n"
+			"8:"
+			: "=a" (s), "=d" (count), "=d" (tmp)
+			: "0" (s), "1" (count));
+	}
+
+	return 0;
+}
+
+
+static inline void *fb_memset255(void *s, size_t count)
+{
+	if (!count)
+		return 0;
+
+	asm volatile ("\n"
+		"	lsr.l	#1,%1 ; jcc 1f ; move.b %2,-(%0)\n"
+		"1:	lsr.l	#1,%1 ; jcc 1f ; move.w %2,-(%0)\n"
+		"1:	lsr.l	#1,%1 ; jcc 1f ; move.l %2,-(%0)\n"
+		"1:	lsr.l	#1,%1 ; jcc 1f ; move.l %2,-(%0) ; move.l %2,-(%0)\n"
+		"1:"
+		: "=a" (s), "=d" (count)
+		: "d" (-1), "0" ((char *)s+count), "1" (count));
+	asm volatile ("\n"
+		"	subq.l	#1,%1 ; jcs 3f\n"
+		"	move.l	%2,%%d4; move.l %2,%%d5; move.l %2,%%d6\n"
+		"2:	movem.l	%2/%%d4/%%d5/%%d6,-(%0)\n"
+		"	dbra	%1,2b\n"
+		"3:"
+		: "=a" (s), "=d" (count)
+		: "d" (-1), "0" (s), "1" (count)
+		: "d4", "d5", "d6");
+
+	return 0;
+}
+
+
+static inline void *fb_memmove(void *d, const void *s, size_t count)
+{
+	if (d < s) {
+		if (count < 16) {
+			asm volatile ("\n"
+				"	lsr.l	#1,%2 ; jcc 1f ; move.b (%1)+,(%0)+\n"
+				"1:	lsr.l	#1,%2 ; jcc 1f ; move.w (%1)+,(%0)+\n"
+				"1:	lsr.l	#1,%2 ; jcc 1f ; move.l (%1)+,(%0)+\n"
+				"1:	lsr.l	#1,%2 ; jcc 1f ; move.l (%1)+,(%0)+ ; move.l (%1)+,(%0)+\n"
+				"1:"
+				: "=a" (d), "=a" (s), "=d" (count)
+				: "0" (d), "1" (s), "2" (count));
+		} else {
+			long tmp;
+			asm volatile ("\n"
+				"	move.l	%0,%3\n"
+				"	lsr.l	#1,%3 ; jcc 1f ; move.b (%1)+,(%0)+ ; subqw #1,%2\n"
+				"	lsr.l	#1,%3 ; jcs 2f\n"  /* %0 increased=>bit 2 switched*/
+				"	move.w	(%1)+,(%0)+  ; subqw  #2,%2 ; jra 2f\n"
+				"1:	lsr.l   #1,%3 ; jcc 2f\n"
+				"	move.w	(%1)+,(%0)+  ; subqw  #2,%2\n"
+				"2:	move.w	%2,%-; lsr.l #2,%2 ; jeq 6f\n"
+				"	lsr.l	#1,%2 ; jcc 3f ; move.l (%1)+,(%0)+\n"
+				"3:	lsr.l	#1,%2 ; jcc 4f ; move.l (%1)+,(%0)+ ; move.l (%1)+,(%0)+\n"
+				"4:	subq.l	#1,%2 ; jcs 6f\n"
+				"5:	move.l	(%1)+,(%0)+; move.l (%1)+,(%0)+\n"
+				"	move.l	(%1)+,(%0)+; move.l (%1)+,(%0)+\n"
+				"	dbra	%2,5b ; clr.w %2; subq.l #1,%2; jcc 5b\n"
+				"6:	move.w	%+,%2; btst #1,%2 ; jeq 7f ; move.w (%1)+,(%0)+\n"
+				"7:	btst	#0,%2 ; jeq 8f ; move.b (%1)+,(%0)+\n"
+				"8:"
+				: "=a" (d), "=a" (s), "=d" (count), "=d" (tmp)
+				: "0" (d), "1" (s), "2" (count));
+		}
+	} else {
+		if (count < 16) {
+			asm volatile ("\n"
+				"	lsr.l	#1,%2 ; jcc 1f ; move.b -(%1),-(%0)\n"
+				"1:	lsr.l	#1,%2 ; jcc 1f ; move.w -(%1),-(%0)\n"
+				"1:	lsr.l	#1,%2 ; jcc 1f ; move.l -(%1),-(%0)\n"
+				"1:	lsr.l	#1,%2 ; jcc 1f ; move.l -(%1),-(%0) ; move.l -(%1),-(%0)\n"
+				"1:"
+				: "=a" (d), "=a" (s), "=d" (count)
+				: "0" ((char *) d + count), "1" ((char *) s + count), "2" (count));
+		} else {
+			long tmp;
+
+			asm volatile ("\n"
+				"	move.l	%0,%3\n"
+				"	lsr.l	#1,%3 ; jcc 1f ; move.b -(%1),-(%0) ; subqw #1,%2\n"
+				"	lsr.l	#1,%3 ; jcs 2f\n"  /* %0 increased=>bit 2 switched*/
+				"	move.w	-(%1),-(%0) ; subqw  #2,%2 ; jra 2f\n"
+				"1:	lsr.l	#1,%3 ; jcc 2f\n"
+				"	move.w	-(%1),-(%0) ; subqw  #2,%2\n"
+				"2:	move.w	%2,%-; lsr.l #2,%2 ; jeq 6f\n"
+				"	lsr.l	#1,%2 ; jcc 3f ; move.l -(%1),-(%0)\n"
+				"3:	lsr.l	#1,%2 ; jcc 4f ; move.l -(%1),-(%0) ; move.l -(%1),-(%0)\n"
+				"4:	subq.l	#1,%2 ; jcs 6f\n"
+				"5:	move.l	-(%1),-(%0); move.l -(%1),-(%0)\n"
+				"	move.l	-(%1),-(%0); move.l -(%1),-(%0)\n"
+				"	dbra	%2,5b ; clr.w %2; subq.l #1,%2; jcc 5b\n"
+				"6:	move.w	%+,%2; btst #1,%2 ; jeq 7f ; move.w -(%1),-(%0)\n"
+				"7:	btst	#0,%2 ; jeq 8f ; move.b -(%1),-(%0)\n"
+				"8:"
+				: "=a" (d), "=a" (s), "=d" (count), "=d" (tmp)
+				: "0" ((char *) d + count), "1" ((char *) s + count), "2" (count));
+		}
+	}
+
+	return 0;
+}
+
+
+/* ++andreas: Simple and fast version of memmove, assumes size is
+   divisible by 16, suitable for moving the whole screen bitplane */
+static inline void fast_memmove(char *dst, const char *src, size_t size)
+{
+	if (!size)
+		return;
+	if (dst < src)
+		asm volatile ("\n"
+			"1:	movem.l	(%0)+,%%d0/%%d1/%%a0/%%a1\n"
+			"	movem.l	%%d0/%%d1/%%a0/%%a1,%1@\n"
+			"	addq.l	#8,%1; addq.l #8,%1\n"
+			"	dbra	%2,1b\n"
+			"	clr.w	%2; subq.l #1,%2\n"
+			"	jcc	1b"
+			: "=a" (src), "=a" (dst), "=d" (size)
+			: "0" (src), "1" (dst), "2" (size / 16 - 1)
+			: "d0", "d1", "a0", "a1", "memory");
+	else
+		asm volatile ("\n"
+			"1:	subq.l	#8,%0; subq.l #8,%0\n"
+			"	movem.l	%0@,%%d0/%%d1/%%a0/%%a1\n"
+			"	movem.l	%%d0/%%d1/%%a0/%%a1,-(%1)\n"
+			"	dbra	%2,1b\n"
+			"	clr.w	%2; subq.l #1,%2\n"
+			"	jcc 1b"
+			: "=a" (src), "=a" (dst), "=d" (size)
+			: "0" (src + size), "1" (dst + size), "2" (size / 16 - 1)
+			: "d0", "d1", "a0", "a1", "memory");
+}
+
+#ifdef BPL
+
+/*
+ * This expands a up to 8 bit color into two longs
+ * for movel operations.
+ */
+static const u32 four2long[] = {
+	0x00000000, 0x000000ff, 0x0000ff00, 0x0000ffff,
+	0x00ff0000, 0x00ff00ff, 0x00ffff00, 0x00ffffff,
+	0xff000000, 0xff0000ff, 0xff00ff00, 0xff00ffff,
+	0xffff0000, 0xffff00ff, 0xffffff00, 0xffffffff,
+};
+
+static inline void expand8_col2mask(u8 c, u32 m[])
+{
+	m[0] = four2long[c & 15];
+#if BPL > 4
+	m[1] = four2long[c >> 4];
+#endif
+}
+
+static inline void expand8_2col2mask(u8 fg, u8 bg, u32 fgm[], u32 bgm[])
+{
+	fgm[0] = four2long[fg & 15] ^ (bgm[0] = four2long[bg & 15]);
+#if BPL > 4
+	fgm[1] = four2long[fg >> 4] ^ (bgm[1] = four2long[bg >> 4]);
+#endif
+}
+
+/*
+ * set an 8bit value to a color
+ */
+static inline void fill8_col(u8 *dst, u32 m[])
+{
+	u32 tmp = m[0];
+	dst[0] = tmp;
+	dst[2] = (tmp >>= 8);
+#if BPL > 2
+	dst[4] = (tmp >>= 8);
+	dst[6] = tmp >> 8;
+#endif
+#if BPL > 4
+	tmp = m[1];
+	dst[8] = tmp;
+	dst[10] = (tmp >>= 8);
+	dst[12] = (tmp >>= 8);
+	dst[14] = tmp >> 8;
+#endif
+}
+
+/*
+ * set an 8bit value according to foreground/background color
+ */
+static inline void fill8_2col(u8 *dst, u8 fg, u8 bg, u32 mask)
+{
+	u32 fgm[2], bgm[2], tmp;
+
+	expand8_2col2mask(fg, bg, fgm, bgm);
+
+	mask |= mask << 8;
+#if BPL > 2
+	mask |= mask << 16;
+#endif
+	tmp = (mask & fgm[0]) ^ bgm[0];
+	dst[0] = tmp;
+	dst[2] = (tmp >>= 8);
+#if BPL > 2
+	dst[4] = (tmp >>= 8);
+	dst[6] = tmp >> 8;
+#endif
+#if BPL > 4
+	tmp = (mask & fgm[1]) ^ bgm[1];
+	dst[8] = tmp;
+	dst[10] = (tmp >>= 8);
+	dst[12] = (tmp >>= 8);
+	dst[14] = tmp >> 8;
+#endif
+}
+
+static const u32 two2word[] = {
+	0x00000000, 0xffff0000, 0x0000ffff, 0xffffffff
+};
+
+static inline void expand16_col2mask(u8 c, u32 m[])
+{
+	m[0] = two2word[c & 3];
+#if BPL > 2
+	m[1] = two2word[(c >> 2) & 3];
+#endif
+#if BPL > 4
+	m[2] = two2word[(c >> 4) & 3];
+	m[3] = two2word[c >> 6];
+#endif
+}
+
+static inline void expand16_2col2mask(u8 fg, u8 bg, u32 fgm[], u32 bgm[])
+{
+	bgm[0] = two2word[bg & 3];
+	fgm[0] = two2word[fg & 3] ^ bgm[0];
+#if BPL > 2
+	bgm[1] = two2word[(bg >> 2) & 3];
+	fgm[1] = two2word[(fg >> 2) & 3] ^ bgm[1];
+#endif
+#if BPL > 4
+	bgm[2] = two2word[(bg >> 4) & 3];
+	fgm[2] = two2word[(fg >> 4) & 3] ^ bgm[2];
+	bgm[3] = two2word[bg >> 6];
+	fgm[3] = two2word[fg >> 6] ^ bgm[3];
+#endif
+}
+
+static inline u32 *fill16_col(u32 *dst, int rows, u32 m[])
+{
+	while (rows) {
+		*dst++ = m[0];
+#if BPL > 2
+		*dst++ = m[1];
+#endif
+#if BPL > 4
+		*dst++ = m[2];
+		*dst++ = m[3];
+#endif
+		rows--;
+	}
+	return dst;
+}
+
+static inline void memmove32_col(void *dst, void *src, u32 mask, u32 h, u32 bytes)
+{
+	u32 *s, *d, v;
+
+        s = src;
+        d = dst;
+        do {
+                v = (*s++ & mask) | (*d  & ~mask);
+                *d++ = v;
+#if BPL > 2
+                v = (*s++ & mask) | (*d  & ~mask);
+                *d++ = v;
+#endif
+#if BPL > 4
+                v = (*s++ & mask) | (*d  & ~mask);
+                *d++ = v;
+                v = (*s++ & mask) | (*d  & ~mask);
+                *d++ = v;
+#endif
+                d = (u32 *)((u8 *)d + bytes);
+                s = (u32 *)((u8 *)s + bytes);
+        } while (--h);
+}
+
+#endif
+
+#endif /* _VIDEO_ATAFB_UTILS_H */