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Commit 1f034456 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven
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fbdev: c2p - Cleanups 

  - Improve comments and naming
  - Convert macros to static inline functions
  - Remove superfluous `break' after `return'
  - Make sure we get a build-time error (undefined reference to
    'c2p_unsupported') in case of future misuse
  - Replace `unsigned long' by `u32' in comp(), as that's what all callers use
  - Use {get,put}_unaligned_be32() in store_planar{,_masked}()
  - Use void * for arbitrary pointers
  - Use a union to represent pixels/words, to avoid casts
Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
parent 8280eb8a
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Showing with 99 additions and 88 deletions
drivers/video/c2p.c
View file @ 1f034456
/* /*
* Fast C2P (Chunky-to-Planar) Conversion * Fast C2P (Chunky-to-Planar) Conversion
* *
* Copyright (C) 2003 Geert Uytterhoeven * Copyright (C) 2003-2008 Geert Uytterhoeven
* *
* NOTES: * NOTES:
* - This code was inspired by Scout's C2P tutorial * - This code was inspired by Scout's C2P tutorial
...@@ -14,6 +14,9 @@ ...@@ -14,6 +14,9 @@
#include <linux/module.h> #include <linux/module.h>
#include <linux/string.h> #include <linux/string.h>
#include <asm/unaligned.h>
#include "c2p.h" #include "c2p.h"
...@@ -21,97 +24,100 @@ ...@@ -21,97 +24,100 @@
* Basic transpose step * Basic transpose step
*/ */
#define _transp(d, i1, i2, shift, mask) \ static inline void _transp(u32 d[], unsigned int i1, unsigned int i2,
do { \ unsigned int shift, u32 mask)
u32 t = (d[i1] ^ (d[i2] >> shift)) & mask; \ {
d[i1] ^= t; \ u32 t = (d[i1] ^ (d[i2] >> shift)) & mask;
d[i2] ^= t << shift; \
} while (0) d[i1] ^= t;
d[i2] ^= t << shift;
}
extern void c2p_unsupported(void);
static inline u32 get_mask(int n) static inline u32 get_mask(unsigned int n)
{ {
switch (n) { switch (n) {
case 1: case 1:
return 0x55555555; return 0x55555555;
break;
case 2: case 2:
return 0x33333333; return 0x33333333;
break;
case 4: case 4:
return 0x0f0f0f0f; return 0x0f0f0f0f;
break;
case 8: case 8:
return 0x00ff00ff; return 0x00ff00ff;
break;
case 16: case 16:
return 0x0000ffff; return 0x0000ffff;
break;
} }
c2p_unsupported();
return 0; return 0;
} }
#define transp_nx1(d, n) \ static inline void transp8(u32 d[], unsigned int n, unsigned int m)
do { \ {
u32 mask = get_mask(n); \ u32 mask = get_mask(n);
/* First block */ \
_transp(d, 0, 1, n, mask); \ switch (m) {
/* Second block */ \ case 1:
_transp(d, 2, 3, n, mask); \ /* First n x 1 block */
/* Third block */ \ _transp(d, 0, 1, n, mask);
_transp(d, 4, 5, n, mask); \ /* Second n x 1 block */
/* Fourth block */ \ _transp(d, 2, 3, n, mask);
_transp(d, 6, 7, n, mask); \ /* Third n x 1 block */
} while (0) _transp(d, 4, 5, n, mask);
/* Fourth n x 1 block */
#define transp_nx2(d, n) \ _transp(d, 6, 7, n, mask);
do { \ return;
u32 mask = get_mask(n); \
/* First block */ \ case 2:
_transp(d, 0, 2, n, mask); \ /* First n x 2 block */
_transp(d, 1, 3, n, mask); \ _transp(d, 0, 2, n, mask);
/* Second block */ \ _transp(d, 1, 3, n, mask);
_transp(d, 4, 6, n, mask); \ /* Second n x 2 block */
_transp(d, 5, 7, n, mask); \ _transp(d, 4, 6, n, mask);
} while (0) _transp(d, 5, 7, n, mask);
return;
#define transp_nx4(d, n) \
do { \ case 4:
u32 mask = get_mask(n); \ /* Single n x 4 block */
_transp(d, 0, 4, n, mask); \ _transp(d, 0, 4, n, mask);
_transp(d, 1, 5, n, mask); \ _transp(d, 1, 5, n, mask);
_transp(d, 2, 6, n, mask); \ _transp(d, 2, 6, n, mask);
_transp(d, 3, 7, n, mask); \ _transp(d, 3, 7, n, mask);
} while (0) return;
}
#define transp(d, n, m) transp_nx ## m(d, n)
c2p_unsupported();
}
/* /*
* Perform a full C2P step on 32 8-bit pixels, stored in 8 32-bit words * Perform a full C2P step on 32 8-bit pixels, stored in 8 32-bit words
* containing * containing
* - 32 8-bit chunky pixels on input * - 32 8-bit chunky pixels on input
* - permuted planar data on output * - permutated planar data (1 plane per 32-bit word) on output
*/ */
static void c2p_8bpp(u32 d[8]) static void c2p_32x8(u32 d[8])
{ {
transp(d, 16, 4); transp8(d, 16, 4);
transp(d, 8, 2); transp8(d, 8, 2);
transp(d, 4, 1); transp8(d, 4, 1);
transp(d, 2, 4); transp8(d, 2, 4);
transp(d, 1, 2); transp8(d, 1, 2);
} }
/* /*
* Array containing the permution indices of the planar data after c2p * Array containing the permutation indices of the planar data after c2p
*/ */
static const int perm_c2p_8bpp[8] = { 7, 5, 3, 1, 6, 4, 2, 0 }; static const int perm_c2p_32x8[8] = { 7, 5, 3, 1, 6, 4, 2, 0 };
/* /*
...@@ -119,8 +125,7 @@ static const int perm_c2p_8bpp[8] = { 7, 5, 3, 1, 6, 4, 2, 0 }; ...@@ -119,8 +125,7 @@ static const int perm_c2p_8bpp[8] = { 7, 5, 3, 1, 6, 4, 2, 0 };
* This is equivalent to (a & mask) | (b & ~mask) * This is equivalent to (a & mask) | (b & ~mask)
*/ */
static inline unsigned long comp(unsigned long a, unsigned long b, static inline u32 comp(u32 a, u32 b, u32 mask)
unsigned long mask)
{ {
return ((a ^ b) & mask) ^ b; return ((a ^ b) & mask) ^ b;
} }
...@@ -130,12 +135,12 @@ static inline unsigned long comp(unsigned long a, unsigned long b, ...@@ -130,12 +135,12 @@ static inline unsigned long comp(unsigned long a, unsigned long b,
* Store a full block of planar data after c2p conversion * Store a full block of planar data after c2p conversion
*/ */
static inline void store_planar(char *dst, u32 dst_inc, u32 bpp, u32 d[8]) static inline void store_planar(void *dst, u32 dst_inc, u32 bpp, u32 d[8])
{ {
int i; int i;
for (i = 0; i < bpp; i++, dst += dst_inc) for (i = 0; i < bpp; i++, dst += dst_inc)
*(u32 *)dst = d[perm_c2p_8bpp[i]]; put_unaligned_be32(d[perm_c2p_32x8[i]], dst);
} }
...@@ -143,13 +148,15 @@ static inline void store_planar(char *dst, u32 dst_inc, u32 bpp, u32 d[8]) ...@@ -143,13 +148,15 @@ static inline void store_planar(char *dst, u32 dst_inc, u32 bpp, u32 d[8])
* Store a partial block of planar data after c2p conversion * Store a partial block of planar data after c2p conversion
*/ */
static inline void store_planar_masked(char *dst, u32 dst_inc, u32 bpp, static inline void store_planar_masked(void *dst, u32 dst_inc, u32 bpp,
u32 d[8], u32 mask) u32 d[8], u32 mask)
{ {
int i; int i;
for (i = 0; i < bpp; i++, dst += dst_inc) for (i = 0; i < bpp; i++, dst += dst_inc)
*(u32 *)dst = comp(d[perm_c2p_8bpp[i]], *(u32 *)dst, mask); put_unaligned_be32(comp(d[perm_c2p_32x8[i]],
get_unaligned_be32(dst), mask),
dst);
} }
...@@ -166,18 +173,21 @@ static inline void store_planar_masked(char *dst, u32 dst_inc, u32 bpp, ...@@ -166,18 +173,21 @@ static inline void store_planar_masked(char *dst, u32 dst_inc, u32 bpp,
* @bpp: Bits per pixel of the planar frame buffer (1-8) * @bpp: Bits per pixel of the planar frame buffer (1-8)
*/ */
void c2p(u8 *dst, const u8 *src, u32 dx, u32 dy, u32 width, u32 height, void c2p(void *dst, const void *src, u32 dx, u32 dy, u32 width, u32 height,
u32 dst_nextline, u32 dst_nextplane, u32 src_nextline, u32 bpp) u32 dst_nextline, u32 dst_nextplane, u32 src_nextline, u32 bpp)
{ {
int dst_idx; union {
u32 d[8], first, last, w; u8 pixels[32];
u32 words[8];
} d;
u32 dst_idx, first, last, w;
const u8 *c; const u8 *c;
u8 *p; void *p;
dst += dy*dst_nextline+(dx & ~31); dst += dy*dst_nextline+(dx & ~31);
dst_idx = dx % 32; dst_idx = dx % 32;
first = ~0UL >> dst_idx; first = 0xffffffffU >> dst_idx;
last = ~(~0UL >> ((dst_idx+width) % 32)); last = ~(0xffffffffU >> ((dst_idx+width) % 32));
while (height--) { while (height--) {
c = src; c = src;
p = dst; p = dst;
...@@ -185,11 +195,12 @@ void c2p(u8 *dst, const u8 *src, u32 dx, u32 dy, u32 width, u32 height, ...@@ -185,11 +195,12 @@ void c2p(u8 *dst, const u8 *src, u32 dx, u32 dy, u32 width, u32 height,
if (dst_idx+width <= 32) { if (dst_idx+width <= 32) {
/* Single destination word */ /* Single destination word */
first &= last; first &= last;
memset(d, 0, sizeof(d)); memset(d.pixels, 0, sizeof(d));
memcpy((u8 *)d+dst_idx, c, width); memcpy(d.pixels+dst_idx, c, width);
c += width; c += width;
c2p_8bpp(d); c2p_32x8(d.words);
store_planar_masked(p, dst_nextplane, bpp, d, first); store_planar_masked(p, dst_nextplane, bpp, d.words,
first);
p += 4; p += 4;
} else { } else {
/* Multiple destination words */ /* Multiple destination words */
...@@ -197,32 +208,32 @@ void c2p(u8 *dst, const u8 *src, u32 dx, u32 dy, u32 width, u32 height, ...@@ -197,32 +208,32 @@ void c2p(u8 *dst, const u8 *src, u32 dx, u32 dy, u32 width, u32 height,
/* Leading bits */ /* Leading bits */
if (dst_idx) { if (dst_idx) {
w = 32 - dst_idx; w = 32 - dst_idx;
memset(d, 0, dst_idx); memset(d.pixels, 0, dst_idx);
memcpy((u8 *)d+dst_idx, c, w); memcpy(d.pixels+dst_idx, c, w);
c += w; c += w;
c2p_8bpp(d); c2p_32x8(d.words);
store_planar_masked(p, dst_nextplane, bpp, d, store_planar_masked(p, dst_nextplane, bpp,
first); d.words, first);
p += 4; p += 4;
w = width-w; w = width-w;
} }
/* Main chunk */ /* Main chunk */
while (w >= 32) { while (w >= 32) {
memcpy(d, c, 32); memcpy(d.pixels, c, 32);
c += 32; c += 32;
c2p_8bpp(d); c2p_32x8(d.words);
store_planar(p, dst_nextplane, bpp, d); store_planar(p, dst_nextplane, bpp, d.words);
p += 4; p += 4;
w -= 32; w -= 32;
} }
/* Trailing bits */ /* Trailing bits */
w %= 32; w %= 32;
if (w > 0) { if (w > 0) {
memcpy(d, c, w); memcpy(d.pixels, c, w);
memset((u8 *)d+w, 0, 32-w); memset(d.pixels+w, 0, 32-w);
c2p_8bpp(d); c2p_32x8(d.words);
store_planar_masked(p, dst_nextplane, bpp, d, store_planar_masked(p, dst_nextplane, bpp,
last); d.words, last);
} }
} }
src += src_nextline; src += src_nextline;
......
drivers/video/c2p.h
View file @ 1f034456
...@@ -10,7 +10,7 @@ ...@@ -10,7 +10,7 @@
#include <linux/types.h> #include <linux/types.h>
extern void c2p(u8 *dst, const u8 *src, u32 dx, u32 dy, u32 width, u32 height, extern void c2p(void *dst, const void *src, u32 dx, u32 dy, u32 width,
u32 dst_nextline, u32 dst_nextplane, u32 src_nextline, u32 height, u32 dst_nextline, u32 dst_nextplane,
u32 bpp); u32 src_nextline, u32 bpp);
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