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00a9d699bc
The function cfb_copyarea is buggy when the copy operation is not aligned on long boundary (4 bytes on 32-bit machines, 8 bytes on 64-bit machines). How to reproduce: - use x86-64 machine - use a framebuffer driver without acceleration (for example uvesafb) - set the framebuffer to 8-bit depth (for example fbset -a 1024x768-60 -depth 8) - load a font with character width that is not a multiple of 8 pixels note: the console-tools package cannot load a font that has width different from 8 pixels. You need to install the packages "kbd" and "console-terminus" and use the program "setfont" to set font width (for example: setfont Uni2-Terminus20x10) - move some text left and right on the bash command line and you get a screen corruption To expose more bugs, put this line to the end of uvesafb_init_info: info->flags |= FBINFO_HWACCEL_COPYAREA | FBINFO_READS_FAST; - Now framebuffer console will use cfb_copyarea for console scrolling. You get a screen corruption when console is scrolled. This patch is a rewrite of cfb_copyarea. It fixes the bugs, with this patch, console scrolling in 8-bit depth with a font width that is not a multiple of 8 pixels works fine. The cfb_copyarea code was very buggy and it looks like it was written and never tried with non-8-pixel font. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
435 lines
11 KiB
C
435 lines
11 KiB
C
/*
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* Generic function for frame buffer with packed pixels of any depth.
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*
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* Copyright (C) 1999-2005 James Simmons <jsimmons@www.infradead.org>
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive for
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* more details.
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*
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* NOTES:
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*
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* This is for cfb packed pixels. Iplan and such are incorporated in the
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* drivers that need them.
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*
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* FIXME
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*
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* Also need to add code to deal with cards endians that are different than
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* the native cpu endians. I also need to deal with MSB position in the word.
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*
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* The two functions or copying forward and backward could be split up like
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* the ones for filling, i.e. in aligned and unaligned versions. This would
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* help moving some redundant computations and branches out of the loop, too.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/fb.h>
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#include <asm/types.h>
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#include <asm/io.h>
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#include "fb_draw.h"
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#if BITS_PER_LONG == 32
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# define FB_WRITEL fb_writel
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# define FB_READL fb_readl
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#else
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# define FB_WRITEL fb_writeq
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# define FB_READL fb_readq
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#endif
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/*
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* Generic bitwise copy algorithm
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*/
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static void
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bitcpy(struct fb_info *p, unsigned long __iomem *dst, unsigned dst_idx,
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const unsigned long __iomem *src, unsigned src_idx, int bits,
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unsigned n, u32 bswapmask)
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{
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unsigned long first, last;
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int const shift = dst_idx-src_idx;
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#if 0
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/*
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* If you suspect bug in this function, compare it with this simple
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* memmove implementation.
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*/
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fb_memmove((char *)dst + ((dst_idx & (bits - 1))) / 8,
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(char *)src + ((src_idx & (bits - 1))) / 8, n / 8);
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return;
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#endif
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first = fb_shifted_pixels_mask_long(p, dst_idx, bswapmask);
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last = ~fb_shifted_pixels_mask_long(p, (dst_idx+n) % bits, bswapmask);
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if (!shift) {
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// Same alignment for source and dest
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if (dst_idx+n <= bits) {
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// Single word
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if (last)
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first &= last;
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FB_WRITEL( comp( FB_READL(src), FB_READL(dst), first), dst);
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} else {
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// Multiple destination words
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// Leading bits
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if (first != ~0UL) {
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FB_WRITEL( comp( FB_READL(src), FB_READL(dst), first), dst);
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dst++;
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src++;
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n -= bits - dst_idx;
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}
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// Main chunk
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n /= bits;
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while (n >= 8) {
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FB_WRITEL(FB_READL(src++), dst++);
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FB_WRITEL(FB_READL(src++), dst++);
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FB_WRITEL(FB_READL(src++), dst++);
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FB_WRITEL(FB_READL(src++), dst++);
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FB_WRITEL(FB_READL(src++), dst++);
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FB_WRITEL(FB_READL(src++), dst++);
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FB_WRITEL(FB_READL(src++), dst++);
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FB_WRITEL(FB_READL(src++), dst++);
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n -= 8;
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}
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while (n--)
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FB_WRITEL(FB_READL(src++), dst++);
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// Trailing bits
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if (last)
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FB_WRITEL( comp( FB_READL(src), FB_READL(dst), last), dst);
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}
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} else {
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/* Different alignment for source and dest */
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unsigned long d0, d1;
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int m;
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int const left = shift & (bits - 1);
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int const right = -shift & (bits - 1);
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if (dst_idx+n <= bits) {
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// Single destination word
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if (last)
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first &= last;
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d0 = FB_READL(src);
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d0 = fb_rev_pixels_in_long(d0, bswapmask);
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if (shift > 0) {
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// Single source word
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d0 <<= left;
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} else if (src_idx+n <= bits) {
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// Single source word
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d0 >>= right;
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} else {
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// 2 source words
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d1 = FB_READL(src + 1);
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d1 = fb_rev_pixels_in_long(d1, bswapmask);
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d0 = d0 >> right | d1 << left;
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}
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d0 = fb_rev_pixels_in_long(d0, bswapmask);
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FB_WRITEL(comp(d0, FB_READL(dst), first), dst);
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} else {
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// Multiple destination words
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/** We must always remember the last value read, because in case
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SRC and DST overlap bitwise (e.g. when moving just one pixel in
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1bpp), we always collect one full long for DST and that might
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overlap with the current long from SRC. We store this value in
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'd0'. */
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d0 = FB_READL(src++);
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d0 = fb_rev_pixels_in_long(d0, bswapmask);
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// Leading bits
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if (shift > 0) {
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// Single source word
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d1 = d0;
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d0 <<= left;
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n -= bits - dst_idx;
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} else {
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// 2 source words
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d1 = FB_READL(src++);
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d1 = fb_rev_pixels_in_long(d1, bswapmask);
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d0 = d0 >> right | d1 << left;
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n -= bits - dst_idx;
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}
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d0 = fb_rev_pixels_in_long(d0, bswapmask);
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FB_WRITEL(comp(d0, FB_READL(dst), first), dst);
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d0 = d1;
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dst++;
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// Main chunk
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m = n % bits;
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n /= bits;
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while ((n >= 4) && !bswapmask) {
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d1 = FB_READL(src++);
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FB_WRITEL(d0 >> right | d1 << left, dst++);
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d0 = d1;
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d1 = FB_READL(src++);
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FB_WRITEL(d0 >> right | d1 << left, dst++);
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d0 = d1;
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d1 = FB_READL(src++);
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FB_WRITEL(d0 >> right | d1 << left, dst++);
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d0 = d1;
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d1 = FB_READL(src++);
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FB_WRITEL(d0 >> right | d1 << left, dst++);
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d0 = d1;
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n -= 4;
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}
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while (n--) {
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d1 = FB_READL(src++);
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d1 = fb_rev_pixels_in_long(d1, bswapmask);
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d0 = d0 >> right | d1 << left;
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d0 = fb_rev_pixels_in_long(d0, bswapmask);
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FB_WRITEL(d0, dst++);
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d0 = d1;
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}
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// Trailing bits
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if (m) {
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if (m <= bits - right) {
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// Single source word
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d0 >>= right;
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} else {
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// 2 source words
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d1 = FB_READL(src);
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d1 = fb_rev_pixels_in_long(d1,
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bswapmask);
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d0 = d0 >> right | d1 << left;
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}
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d0 = fb_rev_pixels_in_long(d0, bswapmask);
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FB_WRITEL(comp(d0, FB_READL(dst), last), dst);
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}
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}
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}
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}
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/*
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* Generic bitwise copy algorithm, operating backward
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*/
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static void
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bitcpy_rev(struct fb_info *p, unsigned long __iomem *dst, unsigned dst_idx,
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const unsigned long __iomem *src, unsigned src_idx, int bits,
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unsigned n, u32 bswapmask)
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{
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unsigned long first, last;
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int shift;
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#if 0
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/*
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* If you suspect bug in this function, compare it with this simple
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* memmove implementation.
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*/
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fb_memmove((char *)dst + ((dst_idx & (bits - 1))) / 8,
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(char *)src + ((src_idx & (bits - 1))) / 8, n / 8);
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return;
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#endif
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dst += (dst_idx + n - 1) / bits;
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src += (src_idx + n - 1) / bits;
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dst_idx = (dst_idx + n - 1) % bits;
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src_idx = (src_idx + n - 1) % bits;
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shift = dst_idx-src_idx;
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first = ~fb_shifted_pixels_mask_long(p, (dst_idx + 1) % bits, bswapmask);
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last = fb_shifted_pixels_mask_long(p, (bits + dst_idx + 1 - n) % bits, bswapmask);
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if (!shift) {
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// Same alignment for source and dest
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if ((unsigned long)dst_idx+1 >= n) {
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// Single word
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if (first)
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last &= first;
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FB_WRITEL( comp( FB_READL(src), FB_READL(dst), last), dst);
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} else {
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// Multiple destination words
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// Leading bits
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if (first) {
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FB_WRITEL( comp( FB_READL(src), FB_READL(dst), first), dst);
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dst--;
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src--;
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n -= dst_idx+1;
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}
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// Main chunk
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n /= bits;
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while (n >= 8) {
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FB_WRITEL(FB_READL(src--), dst--);
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FB_WRITEL(FB_READL(src--), dst--);
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FB_WRITEL(FB_READL(src--), dst--);
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FB_WRITEL(FB_READL(src--), dst--);
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FB_WRITEL(FB_READL(src--), dst--);
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FB_WRITEL(FB_READL(src--), dst--);
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FB_WRITEL(FB_READL(src--), dst--);
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FB_WRITEL(FB_READL(src--), dst--);
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n -= 8;
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}
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while (n--)
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FB_WRITEL(FB_READL(src--), dst--);
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// Trailing bits
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if (last != -1UL)
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FB_WRITEL( comp( FB_READL(src), FB_READL(dst), last), dst);
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}
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} else {
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// Different alignment for source and dest
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unsigned long d0, d1;
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int m;
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int const left = shift & (bits-1);
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int const right = -shift & (bits-1);
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if ((unsigned long)dst_idx+1 >= n) {
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// Single destination word
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if (first)
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last &= first;
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d0 = FB_READL(src);
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if (shift < 0) {
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// Single source word
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d0 >>= right;
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} else if (1+(unsigned long)src_idx >= n) {
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// Single source word
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d0 <<= left;
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} else {
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// 2 source words
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d1 = FB_READL(src - 1);
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d1 = fb_rev_pixels_in_long(d1, bswapmask);
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d0 = d0 << left | d1 >> right;
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}
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d0 = fb_rev_pixels_in_long(d0, bswapmask);
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FB_WRITEL(comp(d0, FB_READL(dst), last), dst);
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} else {
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// Multiple destination words
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/** We must always remember the last value read, because in case
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SRC and DST overlap bitwise (e.g. when moving just one pixel in
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1bpp), we always collect one full long for DST and that might
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overlap with the current long from SRC. We store this value in
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'd0'. */
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d0 = FB_READL(src--);
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d0 = fb_rev_pixels_in_long(d0, bswapmask);
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// Leading bits
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if (shift < 0) {
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// Single source word
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d1 = d0;
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d0 >>= right;
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} else {
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// 2 source words
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d1 = FB_READL(src--);
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d1 = fb_rev_pixels_in_long(d1, bswapmask);
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d0 = d0 << left | d1 >> right;
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}
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d0 = fb_rev_pixels_in_long(d0, bswapmask);
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FB_WRITEL(comp(d0, FB_READL(dst), first), dst);
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d0 = d1;
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dst--;
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n -= dst_idx+1;
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// Main chunk
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m = n % bits;
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n /= bits;
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while ((n >= 4) && !bswapmask) {
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d1 = FB_READL(src--);
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FB_WRITEL(d0 << left | d1 >> right, dst--);
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d0 = d1;
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d1 = FB_READL(src--);
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FB_WRITEL(d0 << left | d1 >> right, dst--);
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d0 = d1;
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d1 = FB_READL(src--);
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FB_WRITEL(d0 << left | d1 >> right, dst--);
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d0 = d1;
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d1 = FB_READL(src--);
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FB_WRITEL(d0 << left | d1 >> right, dst--);
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d0 = d1;
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n -= 4;
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}
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while (n--) {
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d1 = FB_READL(src--);
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d1 = fb_rev_pixels_in_long(d1, bswapmask);
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d0 = d0 << left | d1 >> right;
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d0 = fb_rev_pixels_in_long(d0, bswapmask);
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FB_WRITEL(d0, dst--);
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d0 = d1;
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}
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// Trailing bits
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if (m) {
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if (m <= bits - left) {
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// Single source word
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d0 <<= left;
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} else {
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// 2 source words
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d1 = FB_READL(src);
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d1 = fb_rev_pixels_in_long(d1,
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bswapmask);
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d0 = d0 << left | d1 >> right;
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}
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d0 = fb_rev_pixels_in_long(d0, bswapmask);
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FB_WRITEL(comp(d0, FB_READL(dst), last), dst);
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}
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}
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}
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}
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void cfb_copyarea(struct fb_info *p, const struct fb_copyarea *area)
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{
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u32 dx = area->dx, dy = area->dy, sx = area->sx, sy = area->sy;
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u32 height = area->height, width = area->width;
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unsigned long const bits_per_line = p->fix.line_length*8u;
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unsigned long __iomem *base = NULL;
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int bits = BITS_PER_LONG, bytes = bits >> 3;
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unsigned dst_idx = 0, src_idx = 0, rev_copy = 0;
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u32 bswapmask = fb_compute_bswapmask(p);
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if (p->state != FBINFO_STATE_RUNNING)
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return;
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/* if the beginning of the target area might overlap with the end of
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the source area, be have to copy the area reverse. */
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if ((dy == sy && dx > sx) || (dy > sy)) {
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dy += height;
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sy += height;
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rev_copy = 1;
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}
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// split the base of the framebuffer into a long-aligned address and the
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// index of the first bit
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base = (unsigned long __iomem *)((unsigned long)p->screen_base & ~(bytes-1));
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dst_idx = src_idx = 8*((unsigned long)p->screen_base & (bytes-1));
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// add offset of source and target area
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dst_idx += dy*bits_per_line + dx*p->var.bits_per_pixel;
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src_idx += sy*bits_per_line + sx*p->var.bits_per_pixel;
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if (p->fbops->fb_sync)
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p->fbops->fb_sync(p);
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if (rev_copy) {
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while (height--) {
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dst_idx -= bits_per_line;
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src_idx -= bits_per_line;
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bitcpy_rev(p, base + (dst_idx / bits), dst_idx % bits,
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base + (src_idx / bits), src_idx % bits, bits,
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width*p->var.bits_per_pixel, bswapmask);
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}
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} else {
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while (height--) {
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bitcpy(p, base + (dst_idx / bits), dst_idx % bits,
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base + (src_idx / bits), src_idx % bits, bits,
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width*p->var.bits_per_pixel, bswapmask);
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dst_idx += bits_per_line;
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src_idx += bits_per_line;
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}
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}
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}
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EXPORT_SYMBOL(cfb_copyarea);
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MODULE_AUTHOR("James Simmons <jsimmons@users.sf.net>");
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MODULE_DESCRIPTION("Generic software accelerated copyarea");
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MODULE_LICENSE("GPL");
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