From: Antonino A. Daplas Date: Tue, 13 Dec 2005 06:17:21 +0000 (-0800) Subject: [PATCH] fbdev: Fix incorrect unaligned access in little-endian machines X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=be0d9b6c7aeaad1683059c00131cabd4c894c17c;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git [PATCH] fbdev: Fix incorrect unaligned access in little-endian machines The drawing function cfbfillrect does not work correctly when access is not unsigned-long aligned. It manifests as extra lines of pixels that are not complete drawn. Reversing the shift operator solves the problem, so I would presume that this bug would manifest only on little endian machines. The function cfbcopyarea may also have this bug. Aligned access should present no problems. Signed-off-by: Antonino Daplas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/video/cfbcopyarea.c b/drivers/video/cfbcopyarea.c index cdc71572cf3..74415325b01 100644 --- a/drivers/video/cfbcopyarea.c +++ b/drivers/video/cfbcopyarea.c @@ -64,8 +64,8 @@ bitcpy(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem *src int const shift = dst_idx-src_idx; int left, right; - first = ~0UL >> dst_idx; - last = ~(~0UL >> ((dst_idx+n) % bits)); + first = FB_SHIFT_HIGH(~0UL, dst_idx); + last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits)); if (!shift) { // Same alignment for source and dest @@ -216,8 +216,8 @@ bitcpy_rev(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem shift = dst_idx-src_idx; - first = ~0UL << (bits - 1 - dst_idx); - last = ~(~0UL << (bits - 1 - ((dst_idx-n) % bits))); + first = FB_SHIFT_LOW(~0UL, bits - 1 - dst_idx); + last = ~(FB_SHIFT_LOW(~0UL, bits - 1 - ((dst_idx-n) % bits))); if (!shift) { // Same alignment for source and dest diff --git a/drivers/video/cfbfillrect.c b/drivers/video/cfbfillrect.c index 167d9314e6e..e5ff62e9cfb 100644 --- a/drivers/video/cfbfillrect.c +++ b/drivers/video/cfbfillrect.c @@ -110,8 +110,8 @@ bitfill_aligned(unsigned long __iomem *dst, int dst_idx, unsigned long pat, unsi if (!n) return; - first = ~0UL >> dst_idx; - last = ~(~0UL >> ((dst_idx+n) % bits)); + first = FB_SHIFT_HIGH(~0UL, dst_idx); + last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits)); if (dst_idx+n <= bits) { // Single word @@ -167,8 +167,8 @@ bitfill_unaligned(unsigned long __iomem *dst, int dst_idx, unsigned long pat, if (!n) return; - first = ~0UL >> dst_idx; - last = ~(~0UL >> ((dst_idx+n) % bits)); + first = FB_SHIFT_HIGH(~0UL, dst_idx); + last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits)); if (dst_idx+n <= bits) { // Single word @@ -221,8 +221,8 @@ bitfill_aligned_rev(unsigned long __iomem *dst, int dst_idx, unsigned long pat, if (!n) return; - first = ~0UL >> dst_idx; - last = ~(~0UL >> ((dst_idx+n) % bits)); + first = FB_SHIFT_HIGH(~0UL, dst_idx); + last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits)); if (dst_idx+n <= bits) { // Single word @@ -290,8 +290,8 @@ bitfill_unaligned_rev(unsigned long __iomem *dst, int dst_idx, unsigned long pat if (!n) return; - first = ~0UL >> dst_idx; - last = ~(~0UL >> ((dst_idx+n) % bits)); + first = FB_SHIFT_HIGH(~0UL, dst_idx); + last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits)); if (dst_idx+n <= bits) { // Single word diff --git a/drivers/video/cfbimgblt.c b/drivers/video/cfbimgblt.c index 7a01742a82a..910e2338a27 100644 --- a/drivers/video/cfbimgblt.c +++ b/drivers/video/cfbimgblt.c @@ -76,18 +76,6 @@ static u32 cfb_tab32[] = { #define FB_WRITEL fb_writel #define FB_READL fb_readl -#if defined (__BIG_ENDIAN) -#define LEFT_POS(bpp) (32 - bpp) -#define SHIFT_HIGH(val, bits) ((val) >> (bits)) -#define SHIFT_LOW(val, bits) ((val) << (bits)) -#define BIT_NR(b) (7 - (b)) -#else -#define LEFT_POS(bpp) (0) -#define SHIFT_HIGH(val, bits) ((val) << (bits)) -#define SHIFT_LOW(val, bits) ((val) >> (bits)) -#define BIT_NR(b) (b) -#endif - static inline void color_imageblit(const struct fb_image *image, struct fb_info *p, u8 __iomem *dst1, u32 start_index, @@ -109,7 +97,7 @@ static inline void color_imageblit(const struct fb_image *image, val = 0; if (start_index) { - u32 start_mask = ~(SHIFT_HIGH(~(u32)0, start_index)); + u32 start_mask = ~(FB_SHIFT_HIGH(~(u32)0, start_index)); val = FB_READL(dst) & start_mask; shift = start_index; } @@ -119,20 +107,20 @@ static inline void color_imageblit(const struct fb_image *image, color = palette[*src]; else color = *src; - color <<= LEFT_POS(bpp); - val |= SHIFT_HIGH(color, shift); + color <<= FB_LEFT_POS(bpp); + val |= FB_SHIFT_HIGH(color, shift); if (shift >= null_bits) { FB_WRITEL(val, dst++); val = (shift == null_bits) ? 0 : - SHIFT_LOW(color, 32 - shift); + FB_SHIFT_LOW(color, 32 - shift); } shift += bpp; shift &= (32 - 1); src++; } if (shift) { - u32 end_mask = SHIFT_HIGH(~(u32)0, shift); + u32 end_mask = FB_SHIFT_HIGH(~(u32)0, shift); FB_WRITEL((FB_READL(dst) & end_mask) | val, dst); } @@ -162,8 +150,8 @@ static inline void slow_imageblit(const struct fb_image *image, struct fb_info * u32 i, j, l; dst2 = (u32 __iomem *) dst1; - fgcolor <<= LEFT_POS(bpp); - bgcolor <<= LEFT_POS(bpp); + fgcolor <<= FB_LEFT_POS(bpp); + bgcolor <<= FB_LEFT_POS(bpp); for (i = image->height; i--; ) { shift = val = 0; @@ -174,21 +162,21 @@ static inline void slow_imageblit(const struct fb_image *image, struct fb_info * /* write leading bits */ if (start_index) { - u32 start_mask = ~(SHIFT_HIGH(~(u32)0, start_index)); + u32 start_mask = ~(FB_SHIFT_HIGH(~(u32)0,start_index)); val = FB_READL(dst) & start_mask; shift = start_index; } while (j--) { l--; - color = (*s & 1 << (BIT_NR(l))) ? fgcolor : bgcolor; - val |= SHIFT_HIGH(color, shift); + color = (*s & 1 << (FB_BIT_NR(l))) ? fgcolor : bgcolor; + val |= FB_SHIFT_HIGH(color, shift); /* Did the bitshift spill bits to the next long? */ if (shift >= null_bits) { FB_WRITEL(val, dst++); val = (shift == null_bits) ? 0 : - SHIFT_LOW(color,32 - shift); + FB_SHIFT_LOW(color,32 - shift); } shift += bpp; shift &= (32 - 1); @@ -197,7 +185,7 @@ static inline void slow_imageblit(const struct fb_image *image, struct fb_info * /* write trailing bits */ if (shift) { - u32 end_mask = SHIFT_HIGH(~(u32)0, shift); + u32 end_mask = FB_SHIFT_HIGH(~(u32)0, shift); FB_WRITEL((FB_READL(dst) & end_mask) | val, dst); } diff --git a/include/linux/fb.h b/include/linux/fb.h index dab3a4decb4..a973be2cfe6 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -833,6 +833,18 @@ struct fb_info { #define fb_writeq(b,addr) (*(volatile u64 *) (addr) = (b)) #define fb_memset memset +#endif + +#if defined (__BIG_ENDIAN) +#define FB_LEFT_POS(bpp) (32 - bpp) +#define FB_SHIFT_HIGH(val, bits) ((val) >> (bits)) +#define FB_SHIFT_LOW(val, bits) ((val) << (bits)) +#define FB_BIT_NR(b) (7 - (b)) +#else +#define FB_LEFT_POS(bpp) (0) +#define FB_SHIFT_HIGH(val, bits) ((val) << (bits)) +#define FB_SHIFT_LOW(val, bits) ((val) >> (bits)) +#define FB_BIT_NR(b) (b) #endif /*