drivers/video/cfbcopyarea.c

   1 /*
   2  *  Generic function for frame buffer with packed pixels of any depth.
   3  *
   4  *      Copyright (C)  1999-2005 James Simmons <jsimmons@www.infradead.org>
   5  *
   6  *  This file is subject to the terms and conditions of the GNU General Public
   7  *  License.  See the file COPYING in the main directory of this archive for
   8  *  more details.
   9  *
  10  * NOTES:
  11  *
  12  *  This is for cfb packed pixels. Iplan and such are incorporated in the
  13  *  drivers that need them.
  14  *
  15  *  FIXME
  16  *
  17  *  Also need to add code to deal with cards endians that are different than
  18  *  the native cpu endians. I also need to deal with MSB position in the word.
  19  *
  20  *  The two functions or copying forward and backward could be split up like
  21  *  the ones for filling, i.e. in aligned and unaligned versions. This would
  22  *  help moving some redundant computations and branches out of the loop, too.
  23  */
  24
  25
  26
  27 #include <linux/config.h>
  28 #include <linux/module.h>
  29 #include <linux/kernel.h>
  30 #include <linux/string.h>
  31 #include <linux/fb.h>
  32 #include <linux/slab.h>
  33 #include <asm/types.h>
  34 #include <asm/io.h>
  35
  36 #if BITS_PER_LONG == 32
  37 #  define FB_WRITEL fb_writel
  38 #  define FB_READL  fb_readl
  39 #else
  40 #  define FB_WRITEL fb_writeq
  41 #  define FB_READL  fb_readq
  42 #endif
  43
  44     /*
  45      *  Compose two values, using a bitmask as decision value
  46      *  This is equivalent to (a & mask) | (b & ~mask)
  47      */
  48
  49 static inline unsigned long
  50 comp(unsigned long a, unsigned long b, unsigned long mask)
  51 {
  52     return ((a ^ b) & mask) ^ b;
  53 }
  54
  55     /*
  56      *  Generic bitwise copy algorithm
  57      */
  58
  59 static void
  60 bitcpy(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem *src,
  61         int src_idx, int bits, unsigned n)
  62 {
  63         unsigned long first, last;
  64         int const shift = dst_idx-src_idx;
  65         int left, right;
  66
  67         first = FB_SHIFT_HIGH(~0UL, dst_idx);
  68         last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
  69
  70         if (!shift) {
  71                 // Same alignment for source and dest
  72
  73                 if (dst_idx+n <= bits) {
  74                         // Single word
  75                         if (last)
  76                                 first &= last;
  77                         FB_WRITEL( comp( FB_READL(src), FB_READL(dst), first), dst);
  78                 } else {
  79                         // Multiple destination words
  80
  81                         // Leading bits
  82                         if (first != ~0UL) {
  83                                 FB_WRITEL( comp( FB_READL(src), FB_READL(dst), first), dst);
  84                                 dst++;
  85                                 src++;
  86                                 n -= bits - dst_idx;
  87                         }
  88
  89                         // Main chunk
  90                         n /= bits;
  91                         while (n >= 8) {
  92                                 FB_WRITEL(FB_READL(src++), dst++);
  93                                 FB_WRITEL(FB_READL(src++), dst++);
  94                                 FB_WRITEL(FB_READL(src++), dst++);
  95                                 FB_WRITEL(FB_READL(src++), dst++);
  96                                 FB_WRITEL(FB_READL(src++), dst++);
  97                                 FB_WRITEL(FB_READL(src++), dst++);
  98                                 FB_WRITEL(FB_READL(src++), dst++);
  99                                 FB_WRITEL(FB_READL(src++), dst++);
 100                                 n -= 8;
 101                         }
 102                         while (n--)
 103                                 FB_WRITEL(FB_READL(src++), dst++);
 104
 105                         // Trailing bits
 106                         if (last)
 107                                 FB_WRITEL( comp( FB_READL(src), FB_READL(dst), last), dst);
 108                 }
 109         } else {
 110                 unsigned long d0, d1;
 111                 int m;
 112                 // Different alignment for source and dest
 113
 114                 right = shift & (bits - 1);
 115                 left = -shift & (bits - 1);
 116
 117                 if (dst_idx+n <= bits) {
 118                         // Single destination word
 119                         if (last)
 120                                 first &= last;
 121                         if (shift > 0) {
 122                                 // Single source word
 123                                 FB_WRITEL( comp( FB_READL(src) >> right, FB_READL(dst), first), dst);
 124                         } else if (src_idx+n <= bits) {
 125                                 // Single source word
 126                                 FB_WRITEL( comp(FB_READL(src) << left, FB_READL(dst), first), dst);
 127                         } else {
 128                                 // 2 source words
 129                                 d0 = FB_READL(src++);
 130                                 d1 = FB_READL(src);
 131                                 FB_WRITEL( comp(d0<<left | d1>>right, FB_READL(dst), first), dst);
 132                         }
 133                 } else {
 134                         // Multiple destination words
 135                         /** We must always remember the last value read, because in case
 136                         SRC and DST overlap bitwise (e.g. when moving just one pixel in
 137                         1bpp), we always collect one full long for DST and that might
 138                         overlap with the current long from SRC. We store this value in
 139                         'd0'. */
 140                         d0 = FB_READL(src++);
 141                         // Leading bits
 142                         if (shift > 0) {
 143                                 // Single source word
 144                                 FB_WRITEL( comp(d0 >> right, FB_READL(dst), first), dst);
 145                                 dst++;
 146                                 n -= bits - dst_idx;
 147                         } else {
 148                                 // 2 source words
 149                                 d1 = FB_READL(src++);
 150                                 FB_WRITEL( comp(d0<<left | d1>>right, FB_READL(dst), first), dst);
 151                                 d0 = d1;
 152                                 dst++;
 153                                 n -= bits - dst_idx;
 154                         }
 155
 156                         // Main chunk
 157                         m = n % bits;
 158                         n /= bits;
 159                         while (n >= 4) {
 160                                 d1 = FB_READL(src++);
 161                                 FB_WRITEL(d0 << left | d1 >> right, dst++);
 162                                 d0 = d1;
 163                                 d1 = FB_READL(src++);
 164                                 FB_WRITEL(d0 << left | d1 >> right, dst++);
 165                                 d0 = d1;
 166                                 d1 = FB_READL(src++);
 167                                 FB_WRITEL(d0 << left | d1 >> right, dst++);
 168                                 d0 = d1;
 169                                 d1 = FB_READL(src++);
 170                                 FB_WRITEL(d0 << left | d1 >> right, dst++);
 171                                 d0 = d1;
 172                                 n -= 4;
 173                         }
 174                         while (n--) {
 175                                 d1 = FB_READL(src++);
 176                                 FB_WRITEL(d0 << left | d1 >> right, dst++);
 177                                 d0 = d1;
 178                         }
 179
 180                         // Trailing bits
 181                         if (last) {
 182                                 if (m <= right) {
 183                                         // Single source word
 184                                         FB_WRITEL( comp(d0 << left, FB_READL(dst), last), dst);
 185                                 } else {
 186                                         // 2 source words
 187                                         d1 = FB_READL(src);
 188                                         FB_WRITEL( comp(d0<<left | d1>>right, FB_READL(dst), last), dst);
 189                                 }
 190                         }
 191                 }
 192         }
 193 }
 194
 195     /*
 196      *  Generic bitwise copy algorithm, operating backward
 197      */
 198
 199 static void
 200 bitcpy_rev(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem *src,
 201                 int src_idx, int bits, unsigned n)
 202 {
 203         unsigned long first, last;
 204         int shift;
 205
 206         dst += (n-1)/bits;
 207         src += (n-1)/bits;
 208         if ((n-1) % bits) {
 209                 dst_idx += (n-1) % bits;
 210                 dst += dst_idx >> (ffs(bits) - 1);
 211                 dst_idx &= bits - 1;
 212                 src_idx += (n-1) % bits;
 213                 src += src_idx >> (ffs(bits) - 1);
 214                 src_idx &= bits - 1;
 215         }
 216
 217         shift = dst_idx-src_idx;
 218
 219         first = FB_SHIFT_LOW(~0UL, bits - 1 - dst_idx);
 220         last = ~(FB_SHIFT_LOW(~0UL, bits - 1 - ((dst_idx-n) % bits)));
 221
 222         if (!shift) {
 223                 // Same alignment for source and dest
 224
 225                 if ((unsigned long)dst_idx+1 >= n) {
 226                         // Single word
 227                         if (last)
 228                                 first &= last;
 229                         FB_WRITEL( comp( FB_READL(src), FB_READL(dst), first), dst);
 230                 } else {
 231                         // Multiple destination words
 232
 233                         // Leading bits
 234                         if (first != ~0UL) {
 235                                 FB_WRITEL( comp( FB_READL(src), FB_READL(dst), first), dst);
 236                                 dst--;
 237                                 src--;
 238                                 n -= dst_idx+1;
 239                         }
 240
 241                         // Main chunk
 242                         n /= bits;
 243                         while (n >= 8) {
 244                                 FB_WRITEL(FB_READL(src--), dst--);
 245                                 FB_WRITEL(FB_READL(src--), dst--);
 246                                 FB_WRITEL(FB_READL(src--), dst--);
 247                                 FB_WRITEL(FB_READL(src--), dst--);
 248                                 FB_WRITEL(FB_READL(src--), dst--);
 249                                 FB_WRITEL(FB_READL(src--), dst--);
 250                                 FB_WRITEL(FB_READL(src--), dst--);
 251                                 FB_WRITEL(FB_READL(src--), dst--);
 252                                 n -= 8;
 253                         }
 254                         while (n--)
 255                                 FB_WRITEL(FB_READL(src--), dst--);
 256
 257                         // Trailing bits
 258                         if (last)
 259                                 FB_WRITEL( comp( FB_READL(src), FB_READL(dst), last), dst);
 260                 }
 261         } else {
 262                 // Different alignment for source and dest
 263
 264                 int const left = -shift & (bits-1);
 265                 int const right = shift & (bits-1);
 266
 267                 if ((unsigned long)dst_idx+1 >= n) {
 268                         // Single destination word
 269                         if (last)
 270                                 first &= last;
 271                         if (shift < 0) {
 272                                 // Single source word
 273                                 FB_WRITEL( comp( FB_READL(src)<<left, FB_READL(dst), first), dst);
 274                         } else if (1+(unsigned long)src_idx >= n) {
 275                                 // Single source word
 276                                 FB_WRITEL( comp( FB_READL(src)>>right, FB_READL(dst), first), dst);
 277                         } else {
 278                                 // 2 source words
 279                                 FB_WRITEL( comp( (FB_READL(src)>>right | FB_READL(src-1)<<left), FB_READL(dst), first), dst);
 280                         }
 281                 } else {
 282                         // Multiple destination words
 283                         /** We must always remember the last value read, because in case
 284                         SRC and DST overlap bitwise (e.g. when moving just one pixel in
 285                         1bpp), we always collect one full long for DST and that might
 286                         overlap with the current long from SRC. We store this value in
 287                         'd0'. */
 288                         unsigned long d0, d1;
 289                         int m;
 290
 291                         d0 = FB_READL(src--);
 292                         // Leading bits
 293                         if (shift < 0) {
 294                                 // Single source word
 295                                 FB_WRITEL( comp( (d0 << left), FB_READL(dst), first), dst);
 296                         } else {
 297                                 // 2 source words
 298                                 d1 = FB_READL(src--);
 299                                 FB_WRITEL( comp( (d0>>right | d1<<left), FB_READL(dst), first), dst);
 300                                 d0 = d1;
 301                         }
 302                         dst--;
 303                         n -= dst_idx+1;
 304
 305                         // Main chunk
 306                         m = n % bits;
 307                         n /= bits;
 308                         while (n >= 4) {
 309                                 d1 = FB_READL(src--);
 310                                 FB_WRITEL(d0 >> right | d1 << left, dst--);
 311                                 d0 = d1;
 312                                 d1 = FB_READL(src--);
 313                                 FB_WRITEL(d0 >> right | d1 << left, dst--);
 314                                 d0 = d1;
 315                                 d1 = FB_READL(src--);
 316                                 FB_WRITEL(d0 >> right | d1 << left, dst--);
 317                                 d0 = d1;
 318                                 d1 = FB_READL(src--);
 319                                 FB_WRITEL(d0 >> right | d1 << left, dst--);
 320                                 d0 = d1;
 321                                 n -= 4;
 322                         }
 323                         while (n--) {
 324                                 d1 = FB_READL(src--);
 325                                 FB_WRITEL(d0 >> right | d1 << left, dst--);
 326                                 d0 = d1;
 327                         }
 328
 329                         // Trailing bits
 330                         if (last) {
 331                                 if (m <= left) {
 332                                         // Single source word
 333                                         FB_WRITEL( comp(d0 >> right, FB_READL(dst), last), dst);
 334                                 } else {
 335                                         // 2 source words
 336                                         d1 = FB_READL(src);
 337                                         FB_WRITEL( comp(d0>>right | d1<<left, FB_READL(dst), last), dst);
 338                                 }
 339                         }
 340                 }
 341         }
 342 }
 343
 344 void cfb_copyarea(struct fb_info *p, const struct fb_copyarea *area)
 345 {
 346         u32 dx = area->dx, dy = area->dy, sx = area->sx, sy = area->sy;
 347         u32 height = area->height, width = area->width;
 348         unsigned long const bits_per_line = p->fix.line_length*8u;
 349         unsigned long __iomem *dst = NULL, *src = NULL;
 350         int bits = BITS_PER_LONG, bytes = bits >> 3;
 351         int dst_idx = 0, src_idx = 0, rev_copy = 0;
 352
 353         if (p->state != FBINFO_STATE_RUNNING)
 354                 return;
 355
 356         /* if the beginning of the target area might overlap with the end of
 357         the source area, be have to copy the area reverse. */
 358         if ((dy == sy && dx > sx) || (dy > sy)) {
 359                 dy += height;
 360                 sy += height;
 361                 rev_copy = 1;
 362         }
 363
 364         // split the base of the framebuffer into a long-aligned address and the
 365         // index of the first bit
 366         dst = src = (unsigned long __iomem *)((unsigned long)p->screen_base & ~(bytes-1));
 367         dst_idx = src_idx = 8*((unsigned long)p->screen_base & (bytes-1));
 368         // add offset of source and target area
 369         dst_idx += dy*bits_per_line + dx*p->var.bits_per_pixel;
 370         src_idx += sy*bits_per_line + sx*p->var.bits_per_pixel;
 371
 372         if (p->fbops->fb_sync)
 373                 p->fbops->fb_sync(p);
 374
 375         if (rev_copy) {
 376                 while (height--) {
 377                         dst_idx -= bits_per_line;
 378                         src_idx -= bits_per_line;
 379                         dst += dst_idx >> (ffs(bits) - 1);
 380                         dst_idx &= (bytes - 1);
 381                         src += src_idx >> (ffs(bits) - 1);
 382                         src_idx &= (bytes - 1);
 383                         bitcpy_rev(dst, dst_idx, src, src_idx, bits,
 384                                 width*p->var.bits_per_pixel);
 385                 }
 386         } else {
 387                 while (height--) {
 388                         dst += dst_idx >> (ffs(bits) - 1);
 389                         dst_idx &= (bytes - 1);
 390                         src += src_idx >> (ffs(bits) - 1);
 391                         src_idx &= (bytes - 1);
 392                         bitcpy(dst, dst_idx, src, src_idx, bits,
 393                                 width*p->var.bits_per_pixel);
 394                         dst_idx += bits_per_line;
 395                         src_idx += bits_per_line;
 396                 }
 397         }
 398 }
 399
 400 EXPORT_SYMBOL(cfb_copyarea);
 401
 402 MODULE_AUTHOR("James Simmons <jsimmons@users.sf.net>");
 403 MODULE_DESCRIPTION("Generic software accelerated copyarea");
 404 MODULE_LICENSE("GPL");
 405