cregit-Linux how code gets into the kernel

Release 4.11 drivers/video/fbdev/atafb_utils.h

#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; }

Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz32100.00%1100.00%
Total32100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz48100.00%1100.00%
Total48100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz32100.00%1100.00%
Total32100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz78100.00%1100.00%
Total78100.00%1100.00%

/* ++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"); }

Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz38100.00%1100.00%
Total38100.00%1100.00%

#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 }

Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz45100.00%1100.00%
Total45100.00%1100.00%


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 }

Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz80100.00%1100.00%
Total80100.00%1100.00%

/* * 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 }

Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz120100.00%1100.00%
Total120100.00%1100.00%

/* * 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 }

Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz185100.00%1100.00%
Total185100.00%1100.00%

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 }

Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz84100.00%1100.00%
Total84100.00%1100.00%


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 }

Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz167100.00%1100.00%
Total167100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz81100.00%1100.00%
Total81100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz192100.00%1100.00%
Total192100.00%1100.00%

#endif #endif /* _VIDEO_ATAFB_UTILS_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
Michael Schmitz1263100.00%1100.00%
Total1263100.00%1100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.