![Pavel Pisa](/assets/img/avatar_default.png)
Allow generic frame-buffer code to correctly write texts and blit images for 1, 2 and 4 bit per pixel frame-buffer organizations when pixels in bytes are organized to in opposite order than bytes in long type. Overhead should be reasonable. If option is not selected, than compiler should eliminate completely all overhead. The feature is disabled at compile time if CONFIG_FB_CFB_REV_PIXELS_IN_BYTE is not set. [adaplas] Convert helper functions to macros if feature is not enabled. Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz> Signed-off-by: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
141 lines
3.1 KiB
C
141 lines
3.1 KiB
C
#ifndef _FB_DRAW_H
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#define _FB_DRAW_H
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#include <asm/types.h>
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#include <linux/fb.h>
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/*
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* Compose two values, using a bitmask as decision value
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* This is equivalent to (a & mask) | (b & ~mask)
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*/
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static inline unsigned long
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comp(unsigned long a, unsigned long b, unsigned long mask)
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{
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return ((a ^ b) & mask) ^ b;
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}
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/*
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* Create a pattern with the given pixel's color
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*/
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#if BITS_PER_LONG == 64
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static inline unsigned long
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pixel_to_pat( u32 bpp, u32 pixel)
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{
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switch (bpp) {
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case 1:
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return 0xfffffffffffffffful*pixel;
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case 2:
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return 0x5555555555555555ul*pixel;
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case 4:
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return 0x1111111111111111ul*pixel;
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case 8:
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return 0x0101010101010101ul*pixel;
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case 12:
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return 0x0001001001001001ul*pixel;
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case 16:
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return 0x0001000100010001ul*pixel;
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case 24:
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return 0x0000000001000001ul*pixel;
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case 32:
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return 0x0000000100000001ul*pixel;
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default:
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panic("pixel_to_pat(): unsupported pixelformat\n");
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}
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}
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#else
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static inline unsigned long
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pixel_to_pat( u32 bpp, u32 pixel)
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{
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switch (bpp) {
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case 1:
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return 0xfffffffful*pixel;
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case 2:
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return 0x55555555ul*pixel;
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case 4:
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return 0x11111111ul*pixel;
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case 8:
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return 0x01010101ul*pixel;
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case 12:
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return 0x00001001ul*pixel;
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case 16:
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return 0x00010001ul*pixel;
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case 24:
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return 0x00000001ul*pixel;
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case 32:
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return 0x00000001ul*pixel;
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default:
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panic("pixel_to_pat(): unsupported pixelformat\n");
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}
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}
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#endif
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#ifdef CONFIG_FB_CFB_REV_PIXELS_IN_BYTE
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static inline u32 fb_shifted_pixels_mask_u32(u32 index, u32 bswapmask)
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{
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u32 mask;
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if (!bswapmask) {
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mask = FB_SHIFT_HIGH(~(u32)0, index);
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} else {
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mask = 0xff << FB_LEFT_POS(8);
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mask = FB_SHIFT_LOW(mask, index & (bswapmask)) & mask;
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mask = FB_SHIFT_HIGH(mask, index & ~(bswapmask));
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#if defined(__i386__) || defined(__x86_64__)
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/* Shift argument is limited to 0 - 31 on x86 based CPU's */
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if(index + bswapmask < 32)
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#endif
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mask |= FB_SHIFT_HIGH(~(u32)0,
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(index + bswapmask) & ~(bswapmask));
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}
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return mask;
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}
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static inline unsigned long fb_shifted_pixels_mask_long(u32 index, u32 bswapmask)
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{
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unsigned long mask;
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if (!bswapmask) {
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mask = FB_SHIFT_HIGH(~0UL, index);
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} else {
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mask = 0xff << FB_LEFT_POS(8);
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mask = FB_SHIFT_LOW(mask, index & (bswapmask)) & mask;
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mask = FB_SHIFT_HIGH(mask, index & ~(bswapmask));
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#if defined(__i386__) || defined(__x86_64__)
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/* Shift argument is limited to 0 - 31 on x86 based CPU's */
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if(index + bswapmask < BITS_PER_LONG)
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#endif
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mask |= FB_SHIFT_HIGH(~0UL,
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(index + bswapmask) & ~(bswapmask));
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}
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return mask;
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}
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static inline u32 fb_compute_bswapmask(struct fb_info *info)
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{
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u32 bswapmask = 0;
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unsigned bpp = info->var.bits_per_pixel;
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if ((bpp < 8) && (info->var.nonstd & FB_NONSTD_REV_PIX_IN_B)) {
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/*
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* Reversed order of pixel layout in bytes
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* works only for 1, 2 and 4 bpp
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*/
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bswapmask = 7 - bpp + 1;
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}
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return bswapmask;
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}
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#else /* CONFIG_FB_CFB_REV_PIXELS_IN_BYTE */
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#define fb_shifted_pixels_mask_u32(i, b) FB_SHIFT_HIGH(~(u32)0, (i))
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#define fb_shifted_pixels_mask_long(i, b) FB_SHIFT_HIGH(~0UL, (i))
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#define fb_compute_bswapmask(...) 0
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#endif /* CONFIG_FB_CFB_REV_PIXELS_IN_BYTE */
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#endif /* FB_DRAW_H */
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