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authorAdrian Schmutzler <freifunk@adrianschmutzler.de>2020-02-08 21:58:55 +0100
committerAdrian Schmutzler <freifunk@adrianschmutzler.de>2020-02-14 14:10:51 +0100
commit7d7aa2fd924c27829ec25f825481554dd81bce97 (patch)
tree658b87b89331670266163e522ea5fb52535633cb /target/linux/bcm27xx/patches-4.19/950-0041-Speed-up-console-framebuffer-imageblit-function.patch
parente7bfda2c243e66a75ff966ba04c28b1590b5d24c (diff)
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brcm2708: rename target to bcm27xx
This change makes the names of Broadcom targets consistent by using the common notation based on SoC/CPU ID (which is used internally anyway), bcmXXXX instead of brcmXXXX. This is even used for target TITLE in make menuconfig already, only the short target name used brcm so far. Despite, since subtargets range from bcm2708 to bcm2711, it seems appropriate to use bcm27xx instead of bcm2708 (again, as already done for BOARDNAME). This also renames the packages brcm2708-userland and brcm2708-gpu-fw. Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de> Acked-by: Álvaro Fernández Rojas <noltari@gmail.com>
Diffstat (limited to 'target/linux/bcm27xx/patches-4.19/950-0041-Speed-up-console-framebuffer-imageblit-function.patch')
-rw-r--r--target/linux/bcm27xx/patches-4.19/950-0041-Speed-up-console-framebuffer-imageblit-function.patch209
1 files changed, 209 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-4.19/950-0041-Speed-up-console-framebuffer-imageblit-function.patch b/target/linux/bcm27xx/patches-4.19/950-0041-Speed-up-console-framebuffer-imageblit-function.patch
new file mode 100644
index 0000000000..17d6137728
--- /dev/null
+++ b/target/linux/bcm27xx/patches-4.19/950-0041-Speed-up-console-framebuffer-imageblit-function.patch
@@ -0,0 +1,209 @@
+From f4489532d7a73ded68e1b8a815a71b0fe25e9e21 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