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fbdev: Fix sys_imageblit() for arbitrary image widths
Commit6f29e04938
("fbdev: Improve performance of sys_imageblit()") broke sys_imageblit() for image width that are not aligned to 8-bit boundaries. Fix this by handling the trailing pixels on each line separately. The performance improvements in the original commit do not regress by this change. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Fixes:6f29e04938
("fbdev: Improve performance of sys_imageblit()") Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Javier Martinez Canillas <javierm@redhat.com> Cc: Sam Ravnborg <sam@ravnborg.org> Link: https://patchwork.freedesktop.org/patch/msgid/20220313192952.12058-2-tzimmermann@suse.de
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5d5fb74630
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1 changed files with 25 additions and 4 deletions
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@ -188,7 +188,7 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p,
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{
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u32 fgx = fgcolor, bgx = bgcolor, bpp = p->var.bits_per_pixel;
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u32 ppw = 32/bpp, spitch = (image->width + 7)/8;
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u32 bit_mask, eorx;
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u32 bit_mask, eorx, shift;
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const char *s = image->data, *src;
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u32 *dst;
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const u32 *tab;
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@ -229,17 +229,23 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p,
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for (i = image->height; i--; ) {
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dst = dst1;
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shift = 8;
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src = s;
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/*
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* Manually unroll the per-line copying loop for better
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* performance. This works until we processed the last
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* completely filled source byte (inclusive).
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*/
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switch (ppw) {
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case 4: /* 8 bpp */
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for (j = k; j; j -= 2, ++src) {
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for (j = k; j >= 2; j -= 2, ++src) {
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*dst++ = colortab[(*src >> 4) & bit_mask];
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*dst++ = colortab[(*src >> 0) & bit_mask];
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}
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break;
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case 2: /* 16 bpp */
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for (j = k; j; j -= 4, ++src) {
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for (j = k; j >= 4; j -= 4, ++src) {
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*dst++ = colortab[(*src >> 6) & bit_mask];
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*dst++ = colortab[(*src >> 4) & bit_mask];
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*dst++ = colortab[(*src >> 2) & bit_mask];
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@ -247,7 +253,7 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p,
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}
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break;
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case 1: /* 32 bpp */
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for (j = k; j; j -= 8, ++src) {
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for (j = k; j >= 8; j -= 8, ++src) {
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*dst++ = colortab[(*src >> 7) & bit_mask];
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*dst++ = colortab[(*src >> 6) & bit_mask];
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*dst++ = colortab[(*src >> 5) & bit_mask];
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@ -259,6 +265,21 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p,
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}
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break;
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}
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/*
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* For image widths that are not a multiple of 8, there
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* are trailing pixels left on the current line. Print
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* them as well.
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*/
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for (; j--; ) {
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shift -= ppw;
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*dst++ = colortab[(*src >> shift) & bit_mask];
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if (!shift) {
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shift = 8;
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++src;
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}
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}
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dst1 += p->fix.line_length;
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s += spitch;
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}
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