drivers/video/fbdev/atafb_utils.h

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