+++ /dev/null
-From cac14f80f1e41f9a977c3cd84b0b3b73740818f8 Mon Sep 17 00:00:00 2001
-From: Harm Hanemaaijer <fgenfb@yahoo.com>
-Date: Thu, 20 Jun 2013 20:21:39 +0200
-Subject: [PATCH] Speed up console framebuffer imageblit function
-
-Especially on platforms with a slower CPU but a relatively high
-framebuffer fill bandwidth, like current ARM devices, the existing
-console monochrome imageblit function used to draw console text is
-suboptimal for common pixel depths such as 16bpp and 32bpp. The existing
-code is quite general and can deal with several pixel depths. By creating
-special case functions for 16bpp and 32bpp, by far the most common pixel
-formats used on modern systems, a significant speed-up is attained
-which can be readily felt on ARM-based devices like the Raspberry Pi
-and the Allwinner platform, but should help any platform using the
-fb layer.
-
-The special case functions allow constant folding, eliminating a number
-of instructions including divide operations, and allow the use of an
-unrolled loop, eliminating instructions with a variable shift size,
-reducing source memory access instructions, and eliminating excessive
-branching. These unrolled loops also allow much better code optimization
-by the C compiler. The code that selects which optimized variant is used
-is also simplified, eliminating integer divide instructions.
-
-The speed-up, measured by timing 'cat file.txt' in the console, varies
-between 40% and 70%, when testing on the Raspberry Pi and Allwinner
-ARM-based platforms, depending on font size and the pixel depth, with
-the greater benefit for 32bpp.
-
-Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>
----
- drivers/video/fbdev/core/cfbimgblt.c | 152 ++++++++++++++++++++++++++-
- 1 file changed, 147 insertions(+), 5 deletions(-)
-
---- a/drivers/video/fbdev/core/cfbimgblt.c
-+++ b/drivers/video/fbdev/core/cfbimgblt.c
-@@ -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 (fgenfb@yahoo.com) 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>
-@@ -262,6 +267,133 @@ static inline void fast_imageblit(const
- }
- }
-
-+/*
-+ * 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;
-@@ -294,11 +426,21 @@ void cfb_imageblit(struct fb_info *p, co
- 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
projects / openwrt / staging / chunkeey.git / blobdiff