1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _VIDEO_ATAFB_UTILS_H
3#define _VIDEO_ATAFB_UTILS_H
4
5/* ================================================================= */
6/* Utility Assembler Functions */
7/* ================================================================= */
8
9/* ====================================================================== */
10
11/* Those of a delicate disposition might like to skip the next couple of
12 * pages.
13 *
14 * These functions are drop in replacements for memmove and
15 * memset(_, 0, _). However their five instances add at least a kilobyte
16 * to the object file. You have been warned.
17 *
18 * Not a great fan of assembler for the sake of it, but I think
19 * that these routines are at least 10 times faster than their C
20 * equivalents for large blits, and that's important to the lowest level of
21 * a graphics driver. Question is whether some scheme with the blitter
22 * would be faster. I suspect not for simple text system - not much
23 * asynchrony.
24 *
25 * Code is very simple, just gruesome expansion. Basic strategy is to
26 * increase data moved/cleared at each step to 16 bytes to reduce
27 * instruction per data move overhead. movem might be faster still
28 * For more than 15 bytes, we try to align the write direction on a
29 * longword boundary to get maximum speed. This is even more gruesome.
30 * Unaligned read/write used requires 68020+ - think this is a problem?
31 *
32 * Sorry!
33 */
34
35
36/* ++roman: I've optimized Robert's original versions in some minor
37 * aspects, e.g. moveq instead of movel, let gcc choose the registers,
38 * use movem in some places...
39 * For other modes than 1 plane, lots of more such assembler functions
40 * were needed (e.g. the ones using movep or expanding color values).
41 */
42
43/* ++andreas: more optimizations:
44 subl #65536,d0 replaced by clrw d0; subql #1,d0 for dbcc
45 addal is faster than addaw
46 movep is rather expensive compared to ordinary move's
47 some functions rewritten in C for clarity, no speed loss */
48
49static inline void *fb_memclear_small(void *s, size_t count)
50{
51 if (!count)
52 return 0;
53
54 asm volatile ("\n"
55 " lsr.l #1,%1 ; jcc 1f ; move.b %2,-(%0)\n"
56 "1: lsr.l #1,%1 ; jcc 1f ; move.w %2,-(%0)\n"
57 "1: lsr.l #1,%1 ; jcc 1f ; move.l %2,-(%0)\n"
58 "1: lsr.l #1,%1 ; jcc 1f ; move.l %2,-(%0) ; move.l %2,-(%0)\n"
59 "1:"
60 : "=a" (s), "=d" (count)
61 : "d" (0), "0" ((char *)s + count), "1" (count));
62 asm volatile ("\n"
63 " subq.l #1,%1\n"
64 " jcs 3f\n"
65 " move.l %2,%%d4; move.l %2,%%d5; move.l %2,%%d6\n"
66 "2: movem.l %2/%%d4/%%d5/%%d6,-(%0)\n"
67 " dbra %1,2b\n"
68 "3:"
69 : "=a" (s), "=d" (count)
70 : "d" (0), "0" (s), "1" (count)
71 : "d4", "d5", "d6"
72 );
73
74 return 0;
75}
76
77
78static inline void *fb_memclear(void *s, size_t count)
79{
80 if (!count)
81 return 0;
82
83 if (count < 16) {
84 asm volatile ("\n"
85 " lsr.l #1,%1 ; jcc 1f ; clr.b (%0)+\n"
86 "1: lsr.l #1,%1 ; jcc 1f ; clr.w (%0)+\n"
87 "1: lsr.l #1,%1 ; jcc 1f ; clr.l (%0)+\n"
88 "1: lsr.l #1,%1 ; jcc 1f ; clr.l (%0)+ ; clr.l (%0)+\n"
89 "1:"
90 : "=a" (s), "=d" (count)
91 : "0" (s), "1" (count));
92 } else {
93 long tmp;
94 asm volatile ("\n"
95 " move.l %1,%2\n"
96 " lsr.l #1,%2 ; jcc 1f ; clr.b (%0)+ ; subq.w #1,%1\n"
97 " lsr.l #1,%2 ; jcs 2f\n" /* %0 increased=>bit 2 switched*/
98 " clr.w (%0)+ ; subq.w #2,%1 ; jra 2f\n"
99 "1: lsr.l #1,%2 ; jcc 2f\n"
100 " clr.w (%0)+ ; subq.w #2,%1\n"
101 "2: move.w %1,%2; lsr.l #2,%1 ; jeq 6f\n"
102 " lsr.l #1,%1 ; jcc 3f ; clr.l (%0)+\n"
103 "3: lsr.l #1,%1 ; jcc 4f ; clr.l (%0)+ ; clr.l (%0)+\n"
104 "4: subq.l #1,%1 ; jcs 6f\n"
105 "5: clr.l (%0)+; clr.l (%0)+ ; clr.l (%0)+ ; clr.l (%0)+\n"
106 " dbra %1,5b ; clr.w %1; subq.l #1,%1; jcc 5b\n"
107 "6: move.w %2,%1; btst #1,%1 ; jeq 7f ; clr.w (%0)+\n"
108 "7: btst #0,%1 ; jeq 8f ; clr.b (%0)+\n"
109 "8:"
110 : "=a" (s), "=d" (count), "=d" (tmp)
111 : "0" (s), "1" (count));
112 }
113
114 return 0;
115}
116
117
118static inline void *fb_memset255(void *s, size_t count)
119{
120 if (!count)
121 return 0;
122
123 asm volatile ("\n"
124 " lsr.l #1,%1 ; jcc 1f ; move.b %2,-(%0)\n"
125 "1: lsr.l #1,%1 ; jcc 1f ; move.w %2,-(%0)\n"
126 "1: lsr.l #1,%1 ; jcc 1f ; move.l %2,-(%0)\n"
127 "1: lsr.l #1,%1 ; jcc 1f ; move.l %2,-(%0) ; move.l %2,-(%0)\n"
128 "1:"
129 : "=a" (s), "=d" (count)
130 : "d" (-1), "0" ((char *)s+count), "1" (count));
131 asm volatile ("\n"
132 " subq.l #1,%1 ; jcs 3f\n"
133 " move.l %2,%%d4; move.l %2,%%d5; move.l %2,%%d6\n"
134 "2: movem.l %2/%%d4/%%d5/%%d6,-(%0)\n"
135 " dbra %1,2b\n"
136 "3:"
137 : "=a" (s), "=d" (count)
138 : "d" (-1), "0" (s), "1" (count)
139 : "d4", "d5", "d6");
140
141 return 0;
142}
143
144
145static inline void *fb_memmove(void *d, const void *s, size_t count)
146{
147 if (d < s) {
148 if (count < 16) {
149 asm volatile ("\n"
150 " lsr.l #1,%2 ; jcc 1f ; move.b (%1)+,(%0)+\n"
151 "1: lsr.l #1,%2 ; jcc 1f ; move.w (%1)+,(%0)+\n"
152 "1: lsr.l #1,%2 ; jcc 1f ; move.l (%1)+,(%0)+\n"
153 "1: lsr.l #1,%2 ; jcc 1f ; move.l (%1)+,(%0)+ ; move.l (%1)+,(%0)+\n"
154 "1:"
155 : "=a" (d), "=a" (s), "=d" (count)
156 : "0" (d), "1" (s), "2" (count));
157 } else {
158 long tmp;
159 asm volatile ("\n"
160 " move.l %0,%3\n"
161 " lsr.l #1,%3 ; jcc 1f ; move.b (%1)+,(%0)+ ; subqw #1,%2\n"
162 " lsr.l #1,%3 ; jcs 2f\n" /* %0 increased=>bit 2 switched*/
163 " move.w (%1)+,(%0)+ ; subqw #2,%2 ; jra 2f\n"
164 "1: lsr.l #1,%3 ; jcc 2f\n"
165 " move.w (%1)+,(%0)+ ; subqw #2,%2\n"
166 "2: move.w %2,%-; lsr.l #2,%2 ; jeq 6f\n"
167 " lsr.l #1,%2 ; jcc 3f ; move.l (%1)+,(%0)+\n"
168 "3: lsr.l #1,%2 ; jcc 4f ; move.l (%1)+,(%0)+ ; move.l (%1)+,(%0)+\n"
169 "4: subq.l #1,%2 ; jcs 6f\n"
170 "5: move.l (%1)+,(%0)+; move.l (%1)+,(%0)+\n"
171 " move.l (%1)+,(%0)+; move.l (%1)+,(%0)+\n"
172 " dbra %2,5b ; clr.w %2; subq.l #1,%2; jcc 5b\n"
173 "6: move.w %+,%2; btst #1,%2 ; jeq 7f ; move.w (%1)+,(%0)+\n"
174 "7: btst #0,%2 ; jeq 8f ; move.b (%1)+,(%0)+\n"
175 "8:"
176 : "=a" (d), "=a" (s), "=d" (count), "=d" (tmp)
177 : "0" (d), "1" (s), "2" (count));
178 }
179 } else {
180 if (count < 16) {
181 asm volatile ("\n"
182 " lsr.l #1,%2 ; jcc 1f ; move.b -(%1),-(%0)\n"
183 "1: lsr.l #1,%2 ; jcc 1f ; move.w -(%1),-(%0)\n"
184 "1: lsr.l #1,%2 ; jcc 1f ; move.l -(%1),-(%0)\n"
185 "1: lsr.l #1,%2 ; jcc 1f ; move.l -(%1),-(%0) ; move.l -(%1),-(%0)\n"
186 "1:"
187 : "=a" (d), "=a" (s), "=d" (count)
188 : "0" ((char *) d + count), "1" ((char *) s + count), "2" (count));
189 } else {
190 long tmp;
191
192 asm volatile ("\n"
193 " move.l %0,%3\n"
194 " lsr.l #1,%3 ; jcc 1f ; move.b -(%1),-(%0) ; subqw #1,%2\n"
195 " lsr.l #1,%3 ; jcs 2f\n" /* %0 increased=>bit 2 switched*/
196 " move.w -(%1),-(%0) ; subqw #2,%2 ; jra 2f\n"
197 "1: lsr.l #1,%3 ; jcc 2f\n"
198 " move.w -(%1),-(%0) ; subqw #2,%2\n"
199 "2: move.w %2,%-; lsr.l #2,%2 ; jeq 6f\n"
200 " lsr.l #1,%2 ; jcc 3f ; move.l -(%1),-(%0)\n"
201 "3: lsr.l #1,%2 ; jcc 4f ; move.l -(%1),-(%0) ; move.l -(%1),-(%0)\n"
202 "4: subq.l #1,%2 ; jcs 6f\n"
203 "5: move.l -(%1),-(%0); move.l -(%1),-(%0)\n"
204 " move.l -(%1),-(%0); move.l -(%1),-(%0)\n"
205 " dbra %2,5b ; clr.w %2; subq.l #1,%2; jcc 5b\n"
206 "6: move.w %+,%2; btst #1,%2 ; jeq 7f ; move.w -(%1),-(%0)\n"
207 "7: btst #0,%2 ; jeq 8f ; move.b -(%1),-(%0)\n"
208 "8:"
209 : "=a" (d), "=a" (s), "=d" (count), "=d" (tmp)
210 : "0" ((char *) d + count), "1" ((char *) s + count), "2" (count));
211 }
212 }
213
214 return 0;
215}
216
217
218/* ++andreas: Simple and fast version of memmove, assumes size is
219 divisible by 16, suitable for moving the whole screen bitplane */
220static inline void fast_memmove(char *dst, const char *src, size_t size)
221{
222 if (!size)
223 return;
224 if (dst < src)
225 asm volatile ("\n"
226 "1: movem.l (%0)+,%%d0/%%d1/%%a0/%%a1\n"
227 " movem.l %%d0/%%d1/%%a0/%%a1,%1@\n"
228 " addq.l #8,%1; addq.l #8,%1\n"
229 " dbra %2,1b\n"
230 " clr.w %2; subq.l #1,%2\n"
231 " jcc 1b"
232 : "=a" (src), "=a" (dst), "=d" (size)
233 : "0" (src), "1" (dst), "2" (size / 16 - 1)
234 : "d0", "d1", "a0", "a1", "memory");
235 else
236 asm volatile ("\n"
237 "1: subq.l #8,%0; subq.l #8,%0\n"
238 " movem.l %0@,%%d0/%%d1/%%a0/%%a1\n"
239 " movem.l %%d0/%%d1/%%a0/%%a1,-(%1)\n"
240 " dbra %2,1b\n"
241 " clr.w %2; subq.l #1,%2\n"
242 " jcc 1b"
243 : "=a" (src), "=a" (dst), "=d" (size)
244 : "0" (src + size), "1" (dst + size), "2" (size / 16 - 1)
245 : "d0", "d1", "a0", "a1", "memory");
246}
247
248#ifdef BPL
249
250/*
251 * This expands a up to 8 bit color into two longs
252 * for movel operations.
253 */
254static const u32 four2long[] = {
255 0x00000000, 0x000000ff, 0x0000ff00, 0x0000ffff,
256 0x00ff0000, 0x00ff00ff, 0x00ffff00, 0x00ffffff,
257 0xff000000, 0xff0000ff, 0xff00ff00, 0xff00ffff,
258 0xffff0000, 0xffff00ff, 0xffffff00, 0xffffffff,
259};
260
261static inline void expand8_col2mask(u8 c, u32 m[])
262{
263 m[0] = four2long[c & 15];
264#if BPL > 4
265 m[1] = four2long[c >> 4];
266#endif
267}
268
269static inline void expand8_2col2mask(u8 fg, u8 bg, u32 fgm[], u32 bgm[])
270{
271 fgm[0] = four2long[fg & 15] ^ (bgm[0] = four2long[bg & 15]);
272#if BPL > 4
273 fgm[1] = four2long[fg >> 4] ^ (bgm[1] = four2long[bg >> 4]);
274#endif
275}
276
277/*
278 * set an 8bit value to a color
279 */
280static inline void fill8_col(u8 *dst, u32 m[])
281{
282 u32 tmp = m[0];
283 dst[0] = tmp;
284 dst[2] = (tmp >>= 8);
285#if BPL > 2
286 dst[4] = (tmp >>= 8);
287 dst[6] = tmp >> 8;
288#endif
289#if BPL > 4
290 tmp = m[1];
291 dst[8] = tmp;
292 dst[10] = (tmp >>= 8);
293 dst[12] = (tmp >>= 8);
294 dst[14] = tmp >> 8;
295#endif
296}
297
298/*
299 * set an 8bit value according to foreground/background color
300 */
301static inline void fill8_2col(u8 *dst, u8 fg, u8 bg, u32 mask)
302{
303 u32 fgm[2], bgm[2], tmp;
304
305 expand8_2col2mask(fg, bg, fgm, bgm);
306
307 mask |= mask << 8;
308#if BPL > 2
309 mask |= mask << 16;
310#endif
311 tmp = (mask & fgm[0]) ^ bgm[0];
312 dst[0] = tmp;
313 dst[2] = (tmp >>= 8);
314#if BPL > 2
315 dst[4] = (tmp >>= 8);
316 dst[6] = tmp >> 8;
317#endif
318#if BPL > 4
319 tmp = (mask & fgm[1]) ^ bgm[1];
320 dst[8] = tmp;
321 dst[10] = (tmp >>= 8);
322 dst[12] = (tmp >>= 8);
323 dst[14] = tmp >> 8;
324#endif
325}
326
327static const u32 two2word[] = {
328 0x00000000, 0xffff0000, 0x0000ffff, 0xffffffff
329};
330
331static inline void expand16_col2mask(u8 c, u32 m[])
332{
333 m[0] = two2word[c & 3];
334#if BPL > 2
335 m[1] = two2word[(c >> 2) & 3];
336#endif
337#if BPL > 4
338 m[2] = two2word[(c >> 4) & 3];
339 m[3] = two2word[c >> 6];
340#endif
341}
342
343static inline void expand16_2col2mask(u8 fg, u8 bg, u32 fgm[], u32 bgm[])
344{
345 bgm[0] = two2word[bg & 3];
346 fgm[0] = two2word[fg & 3] ^ bgm[0];
347#if BPL > 2
348 bgm[1] = two2word[(bg >> 2) & 3];
349 fgm[1] = two2word[(fg >> 2) & 3] ^ bgm[1];
350#endif
351#if BPL > 4
352 bgm[2] = two2word[(bg >> 4) & 3];
353 fgm[2] = two2word[(fg >> 4) & 3] ^ bgm[2];
354 bgm[3] = two2word[bg >> 6];
355 fgm[3] = two2word[fg >> 6] ^ bgm[3];
356#endif
357}
358
359static inline u32 *fill16_col(u32 *dst, int rows, u32 m[])
360{
361 while (rows) {
362 *dst++ = m[0];
363#if BPL > 2
364 *dst++ = m[1];
365#endif
366#if BPL > 4
367 *dst++ = m[2];
368 *dst++ = m[3];
369#endif
370 rows--;
371 }
372 return dst;
373}
374
375static inline void memmove32_col(void *dst, void *src, u32 mask, u32 h, u32 bytes)
376{
377 u32 *s, *d, v;
378
379 s = src;
380 d = dst;
381 do {
382 v = (*s++ & mask) | (*d & ~mask);
383 *d++ = v;
384#if BPL > 2
385 v = (*s++ & mask) | (*d & ~mask);
386 *d++ = v;
387#endif
388#if BPL > 4
389 v = (*s++ & mask) | (*d & ~mask);
390 *d++ = v;
391 v = (*s++ & mask) | (*d & ~mask);
392 *d++ = v;
393#endif
394 d = (u32 *)((u8 *)d + bytes);
395 s = (u32 *)((u8 *)s + bytes);
396 } while (--h);
397}
398
399#endif
400
401#endif /* _VIDEO_ATAFB_UTILS_H */
402

source code of linux/drivers/video/fbdev/atafb_utils.h