cregit-Linux how code gets into the kernel

Release 4.11 drivers/video/fbdev/c2p_core.h

/*
 *  Fast C2P (Chunky-to-Planar) Conversion
 *
 *  Copyright (C) 2003-2008 Geert Uytterhoeven
 *
 *  NOTES:
 *    - This code was inspired by Scout's C2P tutorial
 *    - It assumes to run on a big endian system
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License. See the file COPYING in the main directory of this archive
 *  for more details.
 */


    /*
     *  Basic transpose step
     */


static inline void _transp(u32 d[], unsigned int i1, unsigned int i2, unsigned int shift, u32 mask) { u32 t = (d[i1] ^ (d[i2] >> shift)) & mask; d[i1] ^= t; d[i2] ^= t << shift; }

Contributors

PersonTokensPropCommitsCommitProp
Geert Uytterhoeven63100.00%1100.00%
Total63100.00%1100.00%

extern void c2p_unsupported(void);
static inline u32 get_mask(unsigned int n) { switch (n) { case 1: return 0x55555555; case 2: return 0x33333333; case 4: return 0x0f0f0f0f; case 8: return 0x00ff00ff; case 16: return 0x0000ffff; } c2p_unsupported(); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Geert Uytterhoeven53100.00%1100.00%
Total53100.00%1100.00%

/* * Transpose operations on 8 32-bit words */
static inline void transp8(u32 d[], unsigned int n, unsigned int m) { u32 mask = get_mask(n); switch (m) { case 1: /* First n x 1 block */ _transp(d, 0, 1, n, mask); /* Second n x 1 block */ _transp(d, 2, 3, n, mask); /* Third n x 1 block */ _transp(d, 4, 5, n, mask); /* Fourth n x 1 block */ _transp(d, 6, 7, n, mask); return; case 2: /* First n x 2 block */ _transp(d, 0, 2, n, mask); _transp(d, 1, 3, n, mask); /* Second n x 2 block */ _transp(d, 4, 6, n, mask); _transp(d, 5, 7, n, mask); return; case 4: /* Single n x 4 block */ _transp(d, 0, 4, n, mask); _transp(d, 1, 5, n, mask); _transp(d, 2, 6, n, mask); _transp(d, 3, 7, n, mask); return; } c2p_unsupported(); }

Contributors

PersonTokensPropCommitsCommitProp
Geert Uytterhoeven211100.00%1100.00%
Total211100.00%1100.00%

/* * Transpose operations on 4 32-bit words */
static inline void transp4(u32 d[], unsigned int n, unsigned int m) { u32 mask = get_mask(n); switch (m) { case 1: /* First n x 1 block */ _transp(d, 0, 1, n, mask); /* Second n x 1 block */ _transp(d, 2, 3, n, mask); return; case 2: /* Single n x 2 block */ _transp(d, 0, 2, n, mask); _transp(d, 1, 3, n, mask); return; } c2p_unsupported(); }

Contributors

PersonTokensPropCommitsCommitProp
Geert Uytterhoeven99100.00%1100.00%
Total99100.00%1100.00%

/* * Transpose operations on 4 32-bit words (reverse order) */
static inline void transp4x(u32 d[], unsigned int n, unsigned int m) { u32 mask = get_mask(n); switch (m) { case 2: /* Single n x 2 block */ _transp(d, 2, 0, n, mask); _transp(d, 3, 1, n, mask); return; } c2p_unsupported(); }

Contributors

PersonTokensPropCommitsCommitProp
Geert Uytterhoeven67100.00%1100.00%
Total67100.00%1100.00%

/* * Compose two values, using a bitmask as decision value * This is equivalent to (a & mask) | (b & ~mask) */
static inline u32 comp(u32 a, u32 b, u32 mask) { return ((a ^ b) & mask) ^ b; }

Contributors

PersonTokensPropCommitsCommitProp
Geert Uytterhoeven29100.00%1100.00%
Total29100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Geert Uytterhoeven535100.00%2100.00%
Total535100.00%2100.00%
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