fbdev: add drawing functions for framebuffers in system RAM

The generic drawing functions (cfbimgblt, cfbcopyarea, cfbfillrect) assume
that the framebuffer is in IO memory.  However, we have 3 drivers (hecubafb,
arcfb, and vfb) where the framebuffer is allocated from system RAM (via
vmalloc). Using _raw_read/write and family for these drivers (as used in
the cfb* functions) is illegal, especially in other platforms.

Create 3 new drawing functions, based almost entirely from the original
except that the framebuffer memory is assumed to be in system RAM.
These are named as sysimgblt, syscopyarea, and sysfillrect.

Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 291 insertions, 0 deletions

diff --git a/drivers/video/sysimgblt.c b/drivers/video/sysimgblt.c
new file mode 100644
index 000000000000..bd7e7e9d155f
--- /dev/null
+++ b/drivers/video/sysimgblt.c
@@ -0,0 +1,291 @@
+/*
+ *  Generic 1-bit or 8-bit source to 1-32 bit destination expansion
+ *  for frame buffer located in system RAM with packed pixels of any depth.
+ *
+ *  Based almost entirely on cfbimgblt.c
+ *
+ *      Copyright (C)  April 2007 Antonino Daplas <adaplas@pol.net>
+ *
+ *  This file is subject to the terms and conditions of the GNU General Public
+ *  License.  See the file COPYING in the main directory of this archive for
+ *  more details.
+ */
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fb.h>
+#include <asm/types.h>
+
+#define DEBUG
+
+#ifdef DEBUG
+#define DPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt,__FUNCTION__,## args)
+#else
+#define DPRINTK(fmt, args...)
+#endif
+
+static const u32 cfb_tab8[] = {
+#if defined(__BIG_ENDIAN)
+    0x00000000,0x000000ff,0x0000ff00,0x0000ffff,
+    0x00ff0000,0x00ff00ff,0x00ffff00,0x00ffffff,
+    0xff000000,0xff0000ff,0xff00ff00,0xff00ffff,
+    0xffff0000,0xffff00ff,0xffffff00,0xffffffff
+#elif defined(__LITTLE_ENDIAN)
+    0x00000000,0xff000000,0x00ff0000,0xffff0000,
+    0x0000ff00,0xff00ff00,0x00ffff00,0xffffff00,
+    0x000000ff,0xff0000ff,0x00ff00ff,0xffff00ff,
+    0x0000ffff,0xff00ffff,0x00ffffff,0xffffffff
+#else
+#error FIXME: No endianness??
+#endif
+};
+
+static const u32 cfb_tab16[] = {
+#if defined(__BIG_ENDIAN)
+    0x00000000, 0x0000ffff, 0xffff0000, 0xffffffff
+#elif defined(__LITTLE_ENDIAN)
+    0x00000000, 0xffff0000, 0x0000ffff, 0xffffffff
+#else
+#error FIXME: No endianness??
+#endif
+};
+
+static const u32 cfb_tab32[] = {
+        0x00000000, 0xffffffff
+};
+
+static void color_imageblit(const struct fb_image *image, struct fb_info *p,
+                            void *dst1, u32 start_index, u32 pitch_index)
+{
+        /* Draw the penguin */
+        u32 *dst, *dst2;
+        u32 color = 0, val, shift;
+        int i, n, bpp = p->var.bits_per_pixel;
+        u32 null_bits = 32 - bpp;
+        u32 *palette = (u32 *) p->pseudo_palette;
+        const u8 *src = image->data;
+
+        dst2 = dst1;
+        for (i = image->height; i--; ) {
+                n = image->width;
+                dst = dst1;
+                shift = 0;
+                val = 0;
+
+                if (start_index) {
+                        u32 start_mask = ~(FB_SHIFT_HIGH(~(u32)0,
+                                                         start_index));
+                        val = *dst & start_mask;
+                        shift = start_index;
+                }
+                while (n--) {
+                        if (p->fix.visual == FB_VISUAL_TRUECOLOR ||
+                            p->fix.visual == FB_VISUAL_DIRECTCOLOR )
+                                color = palette[*src];
+                        else
+                                color = *src;
+                        color <<= FB_LEFT_POS(bpp);
+                        val |= FB_SHIFT_HIGH(color, shift);
+                        if (shift >= null_bits) {
+                                *dst++ = val;
+
+                                val = (shift == null_bits) ? 0 :
+                                        FB_SHIFT_LOW(color, 32 - shift);
+                        }
+                        shift += bpp;
+                        shift &= (32 - 1);
+                        src++;
+                }
+                if (shift) {
+                        u32 end_mask = FB_SHIFT_HIGH(~(u32)0, shift);
+
+                        *dst &= end_mask;
+                        *dst |= val;
+                }
+                dst1 += p->fix.line_length;
+                if (pitch_index) {
+                        dst2 += p->fix.line_length;
+                        dst1 = (u8 *)((long)dst2 & ~(sizeof(u32) - 1));
+
+                        start_index += pitch_index;
+                        start_index &= 32 - 1;
+                }
+        }
+}
+
+static void slow_imageblit(const struct fb_image *image, struct fb_info *p,
+                                  void *dst1, u32 fgcolor, u32 bgcolor,
+                                  u32 start_index, u32 pitch_index)
+{
+        u32 shift, color = 0, bpp = p->var.bits_per_pixel;
+        u32 *dst, *dst2;
+        u32 val, pitch = p->fix.line_length;
+        u32 null_bits = 32 - bpp;
+        u32 spitch = (image->width+7)/8;
+        const u8 *src = image->data, *s;
+        u32 i, j, l;
+
+        dst2 = dst1;
+        fgcolor <<= FB_LEFT_POS(bpp);
+        bgcolor <<= FB_LEFT_POS(bpp);
+
+        for (i = image->height; i--; ) {
+                shift = val = 0;
+                l = 8;
+                j = image->width;
+                dst = dst1;
+                s = src;
+
+                /* write leading bits */
+                if (start_index) {
+                        u32 start_mask = ~(FB_SHIFT_HIGH(~(u32)0,start_index));
+                        val = *dst & start_mask;
+                        shift = start_index;
+                }
+
+                while (j--) {
+                        l--;
+                        color = (*s & (1 << l)) ? fgcolor : bgcolor;
+                        val |= FB_SHIFT_HIGH(color, shift);
+
+                        /* Did the bitshift spill bits to the next long? */
+                        if (shift >= null_bits) {
+                                *dst++ = val;
+                                val = (shift == null_bits) ? 0 :
+                                        FB_SHIFT_LOW(color,32 - shift);
+                        }
+                        shift += bpp;
+                        shift &= (32 - 1);
+                        if (!l) { l = 8; s++; };
+                }
+
+                /* write trailing bits */
+                if (shift) {
+                        u32 end_mask = FB_SHIFT_HIGH(~(u32)0, shift);
+
+                        *dst &= end_mask;
+                        *dst |= val;
+                }
+
+                dst1 += pitch;
+                src += spitch;
+                if (pitch_index) {
+                        dst2 += pitch;
+                        dst1 = (u8 *)((long)dst2 & ~(sizeof(u32) - 1));
+                        start_index += pitch_index;
+                        start_index &= 32 - 1;
+                }
+
+        }
+}
+
+/*
+ * fast_imageblit - optimized monochrome color expansion
+ *
+ * Only if:  bits_per_pixel == 8, 16, or 32
+ *           image->width is divisible by pixel/dword (ppw);
+ *           fix->line_legth is divisible by 4;
+ *           beginning and end of a scanline is dword aligned
+ */
+static void fast_imageblit(const struct fb_image *image, struct fb_info *p,
+                                  void *dst1, u32 fgcolor, u32 bgcolor)
+{
+        u32 fgx = fgcolor, bgx = bgcolor, bpp = p->var.bits_per_pixel;
+        u32 ppw = 32/bpp, spitch = (image->width + 7)/8;
+        u32 bit_mask, end_mask, eorx, shift;
+        const char *s = image->data, *src;
+        u32 *dst;
+        const u32 *tab = NULL;
+        int i, j, k;
+
+        switch (bpp) {
+        case 8:
+                tab = cfb_tab8;
+                break;
+        case 16:
+                tab = cfb_tab16;
+                break;
+        case 32:
+        default:
+                tab = cfb_tab32;
+                break;
+        }
+
+        for (i = ppw-1; i--; ) {
+                fgx <<= bpp;
+                bgx <<= bpp;
+                fgx |= fgcolor;
+                bgx |= bgcolor;
+        }
+
+        bit_mask = (1 << ppw) - 1;
+        eorx = fgx ^ bgx;
+        k = image->width/ppw;
+
+        for (i = image->height; i--; ) {
+                dst = dst1;
+                shift = 8;
+                src = s;
+
+                for (j = k; j--; ) {
+                        shift -= ppw;
+                        end_mask = tab[(*src >> shift) & bit_mask];
+                        *dst++ = (end_mask & eorx) ^ bgx;
+                        if (!shift) {
+                                shift = 8;
+                                src++;
+                        }
+                }
+                dst1 += p->fix.line_length;
+                s += spitch;
+        }
+}
+
+void sys_imageblit(struct fb_info *p, const struct fb_image *image)
+{
+        u32 fgcolor, bgcolor, start_index, bitstart, pitch_index = 0;
+        u32 bpl = sizeof(u32), bpp = p->var.bits_per_pixel;
+        u32 width = image->width;
+        u32 dx = image->dx, dy = image->dy;
+        void *dst1;
+
+        if (p->state != FBINFO_STATE_RUNNING)
+                return;
+
+        bitstart = (dy * p->fix.line_length * 8) + (dx * bpp);
+        start_index = bitstart & (32 - 1);
+        pitch_index = (p->fix.line_length & (bpl - 1)) * 8;
+
+        bitstart /= 8;
+        bitstart &= ~(bpl - 1);
+        dst1 = (void __force *)p->screen_base + bitstart;
+
+        if (p->fbops->fb_sync)
+                p->fbops->fb_sync(p);
+
+        if (image->depth == 1) {
+                if (p->fix.visual == FB_VISUAL_TRUECOLOR ||
+                    p->fix.visual == FB_VISUAL_DIRECTCOLOR) {
+                        fgcolor = ((u32*)(p->pseudo_palette))[image->fg_color];
+                        bgcolor = ((u32*)(p->pseudo_palette))[image->bg_color];
+                } else {
+                        fgcolor = image->fg_color;
+                        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
+                        slow_imageblit(image, p, dst1, fgcolor, bgcolor,
+                                        start_index, pitch_index);
+        } else
+                color_imageblit(image, p, dst1, start_index, pitch_index);
+}
+
+EXPORT_SYMBOL(sys_imageblit);
+
+MODULE_AUTHOR("Antonino Daplas <adaplas@pol.net>");
+MODULE_DESCRIPTION("1-bit/8-bit to 1-32 bit color expansion (sys-to-sys)");
+MODULE_LICENSE("GPL");
+