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Commit 15afdd43 authored by Pavel Pisa's avatar Pavel Pisa Committed by Linus Torvalds
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fbdev: copyarea function taught to fully support swapped pixel order in byte 



This correct case, when source and destination X coordinates difference is n
multiple of pixels in byte.  This is probably rare case, but this case should
supported for completeness.

Reorganization of FB_READL and FB_WRITEL calls results in code size decrease
for normal build without swapping support and size with support enabled is
reasonable too.

[adaplas]
Add missing fb_rev_pixels_in_long() prototype.

Signed-off-by: default avatarPavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: default avatarAntonino Daplas <adaplas@gmail.com>
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c3ca34f9

drivers/video/cfbcopyarea.c

+61 −25
Original line number Diff line number Diff line
@@ -94,29 +94,34 @@ bitcpy(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem *src 
				FB_WRITEL( comp( FB_READL(src), FB_READL(dst), last), dst);

		}

	} else {

		/* Different alignment for source and dest */

		unsigned long d0, d1;

		int m;

		// Different alignment for source and dest



		right = shift & (bits - 1);

		left = -shift & (bits - 1);

		bswapmask &= shift;



		if (dst_idx+n <= bits) {

			// Single destination word

			if (last)

				first &= last;

			d0 = FB_READL(src);

			d0 = fb_rev_pixels_in_long(d0, bswapmask);

			if (shift > 0) {

				// Single source word

				FB_WRITEL( comp( FB_READL(src) >> right, FB_READL(dst), first), dst);

				d0 >>= right;

			} else if (src_idx+n <= bits) {

				// Single source word

				FB_WRITEL( comp(FB_READL(src) << left, FB_READL(dst), first), dst);

				d0 <<= left;;

			} else {

				// 2 source words

				d0 = FB_READL(src++);

				d1 = FB_READL(src);

				FB_WRITEL( comp(d0<<left | d1>>right, FB_READL(dst), first), dst);

				d1 = FB_READL(src + 1);

				d1 = fb_rev_pixels_in_long(d1, bswapmask);

				d0 = d0<<left | d1>>right;

			}

			d0 = fb_rev_pixels_in_long(d0, bswapmask);

			FB_WRITEL(comp(d0, FB_READL(dst), first), dst);

		} else {

			// Multiple destination words

			/** We must always remember the last value read, because in case
@@ -125,25 +130,31 @@ bitcpy(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem *src 
			overlap with the current long from SRC. We store this value in

			'd0'. */

			d0 = FB_READL(src++);

			d0 = fb_rev_pixels_in_long(d0, bswapmask);

			// Leading bits

			if (shift > 0) {

				// Single source word

				FB_WRITEL( comp(d0 >> right, FB_READL(dst), first), dst);

				d1 = d0;

				d0 >>= right;

				dst++;

				n -= bits - dst_idx;

			} else {

				// 2 source words

				d1 = FB_READL(src++);

				FB_WRITEL( comp(d0<<left | d1>>right, FB_READL(dst), first), dst);

				d0 = d1;

				d1 = fb_rev_pixels_in_long(d1, bswapmask);



				d0 = d0<<left | d1>>right;

				dst++;

				n -= bits - dst_idx;

			}

			d0 = fb_rev_pixels_in_long(d0, bswapmask);

			FB_WRITEL(comp(d0, FB_READL(dst), first), dst);

			d0 = d1;



			// Main chunk

			m = n % bits;

			n /= bits;

			while (n >= 4) {

			while ((n >= 4) && !bswapmask) {

				d1 = FB_READL(src++);

				FB_WRITEL(d0 << left | d1 >> right, dst++);

				d0 = d1;
@@ -160,7 +171,10 @@ bitcpy(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem *src 
			}

			while (n--) {

				d1 = FB_READL(src++);

				FB_WRITEL(d0 << left | d1 >> right, dst++);

				d1 = fb_rev_pixels_in_long(d1, bswapmask);

				d0 = d0 << left | d1 >> right;

				d0 = fb_rev_pixels_in_long(d0, bswapmask);

				FB_WRITEL(d0, dst++);

				d0 = d1;

			}
@@ -168,12 +182,16 @@ bitcpy(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem *src 
			if (last) {

				if (m <= right) {

					// Single source word

					FB_WRITEL( comp(d0 << left, FB_READL(dst), last), dst);

					d0 <<= left;

				} else {

					// 2 source words

					d1 = FB_READL(src);

					FB_WRITEL( comp(d0<<left | d1>>right, FB_READL(dst), last), dst);

					d1 = fb_rev_pixels_in_long(d1,

								bswapmask);

					d0 = d0<<left | d1>>right;

				}

				d0 = fb_rev_pixels_in_long(d0, bswapmask);

				FB_WRITEL(comp(d0, FB_READL(dst), last), dst);

			}

		}

	}
@@ -247,24 +265,32 @@ bitcpy_rev(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem 
		}

	} else {

		// Different alignment for source and dest

		unsigned long d0, d1;

		int m;



		int const left = -shift & (bits-1);

		int const right = shift & (bits-1);

		bswapmask &= shift;



		if ((unsigned long)dst_idx+1 >= n) {

			// Single destination word

			if (last)

				first &= last;

			d0 = FB_READL(src);

			if (shift < 0) {

				// Single source word

				FB_WRITEL( comp( FB_READL(src)<<left, FB_READL(dst), first), dst);

				d0 <<= left;

			} else if (1+(unsigned long)src_idx >= n) {

				// Single source word

				FB_WRITEL( comp( FB_READL(src)>>right, FB_READL(dst), first), dst);

				d0 >>= right;

			} else {

				// 2 source words

				FB_WRITEL( comp( (FB_READL(src)>>right | FB_READL(src-1)<<left), FB_READL(dst), first), dst);

				d1 = FB_READL(src - 1);

				d1 = fb_rev_pixels_in_long(d1, bswapmask);

				d0 = d0>>right | d1<<left;

			}

			d0 = fb_rev_pixels_in_long(d0, bswapmask);

			FB_WRITEL(comp(d0, FB_READL(dst), first), dst);

		} else {

			// Multiple destination words

			/** We must always remember the last value read, because in case
@@ -272,27 +298,30 @@ bitcpy_rev(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem 
			1bpp), we always collect one full long for DST and that might

			overlap with the current long from SRC. We store this value in

			'd0'. */

			unsigned long d0, d1;

			int m;



			d0 = FB_READL(src--);

			d0 = fb_rev_pixels_in_long(d0, bswapmask);

			// Leading bits

			if (shift < 0) {

				// Single source word

				FB_WRITEL( comp( (d0 << left), FB_READL(dst), first), dst);

				d1 = d0;

				d0 <<= left;

			} else {

				// 2 source words

				d1 = FB_READL(src--);

				FB_WRITEL( comp( (d0>>right | d1<<left), FB_READL(dst), first), dst);

				d0 = d1;

				d1 = fb_rev_pixels_in_long(d1, bswapmask);

				d0 = d0>>right | d1<<left;

			}

			d0 = fb_rev_pixels_in_long(d0, bswapmask);

			FB_WRITEL(comp(d0, FB_READL(dst), first), dst);

			d0 = d1;

			dst--;

			n -= dst_idx+1;



			// Main chunk

			m = n % bits;

			n /= bits;

			while (n >= 4) {

			while ((n >= 4) && !bswapmask) {

				d1 = FB_READL(src--);

				FB_WRITEL(d0 >> right | d1 << left, dst--);

				d0 = d1;
@@ -309,7 +338,10 @@ bitcpy_rev(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem 
			}

			while (n--) {

				d1 = FB_READL(src--);

				FB_WRITEL(d0 >> right | d1 << left, dst--);

				d1 = fb_rev_pixels_in_long(d1, bswapmask);

				d0 = d0 >> right | d1 << left;

				d0 = fb_rev_pixels_in_long(d0, bswapmask);

				FB_WRITEL(d0, dst--);

				d0 = d1;

			}
@@ -317,12 +349,16 @@ bitcpy_rev(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem 
			if (last) {

				if (m <= left) {

					// Single source word

					FB_WRITEL( comp(d0 >> right, FB_READL(dst), last), dst);

					d0 >>= right;

				} else {

					// 2 source words

					d1 = FB_READL(src);

					FB_WRITEL( comp(d0>>right | d1<<left, FB_READL(dst), last), dst);

					d1 = fb_rev_pixels_in_long(d1,

								bswapmask);

					d0 = d0>>right | d1<<left;

				}

				d0 = fb_rev_pixels_in_long(d0, bswapmask);

				FB_WRITEL(comp(d0, FB_READL(dst), last), dst);

			}

		}

	}

drivers/video/fb_draw.h

+26 −0
Original line number Diff line number Diff line
@@ -72,6 +72,26 @@ pixel_to_pat( u32 bpp, u32 pixel) 
#endif



#ifdef CONFIG_FB_CFB_REV_PIXELS_IN_BYTE

#if BITS_PER_LONG == 64

#define REV_PIXELS_MASK1 0x5555555555555555ul

#define REV_PIXELS_MASK2 0x3333333333333333ul

#define REV_PIXELS_MASK4 0x0f0f0f0f0f0f0f0ful

#else

#define REV_PIXELS_MASK1 0x55555555ul

#define REV_PIXELS_MASK2 0x33333333ul

#define REV_PIXELS_MASK4 0x0f0f0f0ful

#endif



static inline unsigned long fb_rev_pixels_in_long(unsigned long val,

						  u32 bswapmask)

{

	if (bswapmask & 1)

		val = comp(val >> 1, val << 1, REV_PIXELS_MASK1);

	if (bswapmask & 2)

		val = comp(val >> 2, val << 2, REV_PIXELS_MASK2);

	if (bswapmask & 3)

		val = comp(val >> 4, val << 4, REV_PIXELS_MASK4);

}



static inline u32 fb_shifted_pixels_mask_u32(u32 index, u32 bswapmask)

{
@@ -131,6 +151,12 @@ static inline u32 fb_compute_bswapmask(struct fb_info *info) 


#else /* CONFIG_FB_CFB_REV_PIXELS_IN_BYTE */



static inline unsigned long fb_rev_pixels_in_long(unsigned long val,

						  u32 bswapmask)

{

	return val;

}



#define fb_shifted_pixels_mask_u32(i, b) FB_SHIFT_HIGH(~(u32)0, (i))

#define fb_shifted_pixels_mask_long(i, b) FB_SHIFT_HIGH(~0UL, (i))

#define fb_compute_bswapmask(...) 0