cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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c2p_iplan2.c (3576B)

      1/*
      2 *  Fast C2P (Chunky-to-Planar) Conversion
      3 *
      4 *  Copyright (C) 2003-2008 Geert Uytterhoeven
      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
      8 *  for more details.
      9 */
     10
     11#include <linux/module.h>
     12#include <linux/string.h>
     13
     14#include <asm/unaligned.h>
     15
     16#include "c2p.h"
     17#include "c2p_core.h"
     18
     19
     20    /*
     21     *  Perform a full C2P step on 16 8-bit pixels, stored in 4 32-bit words
     22     *  containing
     23     *    - 16 8-bit chunky pixels on input
     24     *    - permutated planar data (2 planes per 32-bit word) on output
     25     */
     26
     27static void c2p_16x8(u32 d[4])
     28{
     29	transp4(d, 8, 2);
     30	transp4(d, 1, 2);
     31	transp4x(d, 16, 2);
     32	transp4x(d, 2, 2);
     33	transp4(d, 4, 1);
     34}
     35
     36
     37    /*
     38     *  Array containing the permutation indices of the planar data after c2p
     39     */
     40
     41static const int perm_c2p_16x8[4] = { 1, 3, 0, 2 };
     42
     43
     44    /*
     45     *  Store a full block of iplan2 data after c2p conversion
     46     */
     47
     48static inline void store_iplan2(void *dst, u32 bpp, u32 d[4])
     49{
     50	int i;
     51
     52	for (i = 0; i < bpp/2; i++, dst += 4)
     53		put_unaligned_be32(d[perm_c2p_16x8[i]], dst);
     54}
     55
     56
     57    /*
     58     *  Store a partial block of iplan2 data after c2p conversion
     59     */
     60
     61static inline void store_iplan2_masked(void *dst, u32 bpp, u32 d[4], u32 mask)
     62{
     63	int i;
     64
     65	for (i = 0; i < bpp/2; i++, dst += 4)
     66		put_unaligned_be32(comp(d[perm_c2p_16x8[i]],
     67					get_unaligned_be32(dst), mask),
     68				   dst);
     69}
     70
     71
     72    /*
     73     *  c2p_iplan2 - Copy 8-bit chunky image data to an interleaved planar
     74     *  frame buffer with 2 bytes of interleave
     75     *  @dst: Starting address of the planar frame buffer
     76     *  @dx: Horizontal destination offset (in pixels)
     77     *  @dy: Vertical destination offset (in pixels)
     78     *  @width: Image width (in pixels)
     79     *  @height: Image height (in pixels)
     80     *  @dst_nextline: Frame buffer offset to the next line (in bytes)
     81     *  @src_nextline: Image offset to the next line (in bytes)
     82     *  @bpp: Bits per pixel of the planar frame buffer (2, 4, or 8)
     83     */
     84
     85void c2p_iplan2(void *dst, const void *src, u32 dx, u32 dy, u32 width,
     86		u32 height, u32 dst_nextline, u32 src_nextline, u32 bpp)
     87{
     88	union {
     89		u8 pixels[16];
     90		u32 words[4];
     91	} d;
     92	u32 dst_idx, first, last, w;
     93	const u8 *c;
     94	void *p;
     95
     96	dst += dy*dst_nextline+(dx & ~15)*bpp;
     97	dst_idx = dx % 16;
     98	first = 0xffffU >> dst_idx;
     99	first |= first << 16;
    100	last = 0xffffU ^ (0xffffU >> ((dst_idx+width) % 16));
    101	last |= last << 16;
    102	while (height--) {
    103		c = src;
    104		p = dst;
    105		w = width;
    106		if (dst_idx+width <= 16) {
    107			/* Single destination word */
    108			first &= last;
    109			memset(d.pixels, 0, sizeof(d));
    110			memcpy(d.pixels+dst_idx, c, width);
    111			c += width;
    112			c2p_16x8(d.words);
    113			store_iplan2_masked(p, bpp, d.words, first);
    114			p += bpp*2;
    115		} else {
    116			/* Multiple destination words */
    117			w = width;
    118			/* Leading bits */
    119			if (dst_idx) {
    120				w = 16 - dst_idx;
    121				memset(d.pixels, 0, dst_idx);
    122				memcpy(d.pixels+dst_idx, c, w);
    123				c += w;
    124				c2p_16x8(d.words);
    125				store_iplan2_masked(p, bpp, d.words, first);
    126				p += bpp*2;
    127				w = width-w;
    128			}
    129			/* Main chunk */
    130			while (w >= 16) {
    131				memcpy(d.pixels, c, 16);
    132				c += 16;
    133				c2p_16x8(d.words);
    134				store_iplan2(p, bpp, d.words);
    135				p += bpp*2;
    136				w -= 16;
    137			}
    138			/* Trailing bits */
    139			w %= 16;
    140			if (w > 0) {
    141				memcpy(d.pixels, c, w);
    142				memset(d.pixels+w, 0, 16-w);
    143				c2p_16x8(d.words);
    144				store_iplan2_masked(p, bpp, d.words, last);
    145			}
    146		}
    147		src += src_nextline;
    148		dst += dst_nextline;
    149	}
    150}
    151EXPORT_SYMBOL_GPL(c2p_iplan2);
    152
    153MODULE_LICENSE("GPL");