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Speed up framebuffer console text rendering #314

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Merged
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Jun 22, 2013
Merged

Speed up framebuffer console text rendering #314

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152 changes: 147 additions & 5 deletions drivers/video/cfbimgblt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,11 @@
*
* Also need to add code to deal with cards endians that are different than
* the native cpu endians. I also need to deal with MSB position in the word.
* Modified by Harm Hanemaaijer ([email protected]) 2013:
* - Provide optimized versions of fast_imageblit for 16 and 32bpp that are
* significantly faster than the previous implementation.
* - Simplify the fast/slow_imageblit selection code, avoiding integer
* divides.
*/
#include <linux/module.h>
#include <linux/string.h>
Expand Down Expand Up @@ -262,6 +267,133 @@ static inline void fast_imageblit(const struct fb_image *image, struct fb_info *
}
}

/*
* Optimized fast_imageblit for bpp == 16. ppw = 2, bit_mask = 3 folded
* into the code, main loop unrolled.
*/

static inline void fast_imageblit16(const struct fb_image *image,
struct fb_info *p, u8 __iomem * dst1,
u32 fgcolor, u32 bgcolor)
{
u32 fgx = fgcolor, bgx = bgcolor;
u32 spitch = (image->width + 7) / 8;
u32 end_mask, eorx;
const char *s = image->data, *src;
u32 __iomem *dst;
const u32 *tab = NULL;
int i, j, k;

tab = fb_be_math(p) ? cfb_tab16_be : cfb_tab16_le;

fgx <<= 16;
bgx <<= 16;
fgx |= fgcolor;
bgx |= bgcolor;

eorx = fgx ^ bgx;
k = image->width / 2;

for (i = image->height; i--;) {
dst = (u32 __iomem *) dst1;
src = s;

j = k;
while (j >= 4) {
u8 bits = *src;
end_mask = tab[(bits >> 6) & 3];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
end_mask = tab[(bits >> 4) & 3];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
end_mask = tab[(bits >> 2) & 3];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
end_mask = tab[bits & 3];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
src++;
j -= 4;
}
if (j != 0) {
u8 bits = *src;
end_mask = tab[(bits >> 6) & 3];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
if (j >= 2) {
end_mask = tab[(bits >> 4) & 3];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
if (j == 3) {
end_mask = tab[(bits >> 2) & 3];
FB_WRITEL((end_mask & eorx) ^ bgx, dst);
}
}
}
dst1 += p->fix.line_length;
s += spitch;
}
}

/*
* Optimized fast_imageblit for bpp == 32. ppw = 1, bit_mask = 1 folded
* into the code, main loop unrolled.
*/

static inline void fast_imageblit32(const struct fb_image *image,
struct fb_info *p, u8 __iomem * dst1,
u32 fgcolor, u32 bgcolor)
{
u32 fgx = fgcolor, bgx = bgcolor;
u32 spitch = (image->width + 7) / 8;
u32 end_mask, eorx;
const char *s = image->data, *src;
u32 __iomem *dst;
const u32 *tab = NULL;
int i, j, k;

tab = cfb_tab32;

eorx = fgx ^ bgx;
k = image->width;

for (i = image->height; i--;) {
dst = (u32 __iomem *) dst1;
src = s;

j = k;
while (j >= 8) {
u8 bits = *src;
end_mask = tab[(bits >> 7) & 1];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
end_mask = tab[(bits >> 6) & 1];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
end_mask = tab[(bits >> 5) & 1];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
end_mask = tab[(bits >> 4) & 1];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
end_mask = tab[(bits >> 3) & 1];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
end_mask = tab[(bits >> 2) & 1];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
end_mask = tab[(bits >> 1) & 1];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
end_mask = tab[bits & 1];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
src++;
j -= 8;
}
if (j != 0) {
u32 bits = (u32) * src;
while (j > 1) {
end_mask = tab[(bits >> 7) & 1];
FB_WRITEL((end_mask & eorx) ^ bgx, dst++);
bits <<= 1;
j--;
}
end_mask = tab[(bits >> 7) & 1];
FB_WRITEL((end_mask & eorx) ^ bgx, dst);
}
dst1 += p->fix.line_length;
s += spitch;
}
}

void cfb_imageblit(struct fb_info *p, const struct fb_image *image)
{
u32 fgcolor, bgcolor, start_index, bitstart, pitch_index = 0;
Expand Down Expand Up @@ -294,11 +426,21 @@ void cfb_imageblit(struct fb_info *p, const struct fb_image *image)
bgcolor = image->bg_color;
}

if (32 % bpp == 0 && !start_index && !pitch_index &&
((width & (32/bpp-1)) == 0) &&
bpp >= 8 && bpp <= 32)
fast_imageblit(image, p, dst1, fgcolor, bgcolor);
else
if (!start_index && !pitch_index) {
if (bpp == 32)
fast_imageblit32(image, p, dst1, fgcolor,
bgcolor);
else if (bpp == 16 && (width & 1) == 0)
fast_imageblit16(image, p, dst1, fgcolor,
bgcolor);
else if (bpp == 8 && (width & 3) == 0)
fast_imageblit(image, p, dst1, fgcolor,
bgcolor);
else
slow_imageblit(image, p, dst1, fgcolor,
bgcolor,
start_index, pitch_index);
} else
slow_imageblit(image, p, dst1, fgcolor, bgcolor,
start_index, pitch_index);
} else
Expand Down