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>
diff --git a/drivers/video/syscopyarea.c b/drivers/video/syscopyarea.c
new file mode 100644
index 0000000..e348893
--- /dev/null
+++ b/drivers/video/syscopyarea.c
@@ -0,0 +1,388 @@
+/*
+ * Generic Bit Block Transfer for frame buffers located in system RAM with
+ * packed pixels of any depth.
+ *
+ * Based almost entirely from cfbcopyarea.c (which is based almost entirely
+ * on Geert Uytterhoeven's copyarea routine)
+ *
+ * Copyright (C) 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/kernel.h>
+#include <linux/string.h>
+#include <linux/fb.h>
+#include <linux/slab.h>
+#include <asm/types.h>
+#include <asm/io.h>
+
+ /*
+ * Compose two values, using a bitmask as decision value
+ * This is equivalent to (a & mask) | (b & ~mask)
+ */
+
+static inline unsigned long
+comp(unsigned long a, unsigned long b, unsigned long mask)
+{
+ return ((a ^ b) & mask) ^ b;
+}
+
+ /*
+ * Generic bitwise copy algorithm
+ */
+
+static void
+bitcpy(unsigned long *dst, int dst_idx, const unsigned long *src,
+ int src_idx, int bits, unsigned n)
+{
+ unsigned long first, last;
+ int const shift = dst_idx-src_idx;
+ int left, right;
+
+ first = FB_SHIFT_HIGH(~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
+
+ if (!shift) {
+ /* Same alignment for source and dest */
+ if (dst_idx+n <= bits) {
+ /* Single word */
+ if (last)
+ first &= last;
+ *dst = comp(*src, *dst, first);
+ } else {
+ /* Multiple destination words */
+ /* Leading bits */
+ if (first != ~0UL) {
+ *dst = comp(*src, *dst, first);
+ dst++;
+ src++;
+ n -= bits - dst_idx;
+ }
+
+ /* Main chunk */
+ n /= bits;
+ while (n >= 8) {
+ *dst++ = *src++;
+ *dst++ = *src++;
+ *dst++ = *src++;
+ *dst++ = *src++;
+ *dst++ = *src++;
+ *dst++ = *src++;
+ *dst++ = *src++;
+ *dst++ = *src++;
+ n -= 8;
+ }
+ while (n--)
+ *dst++ = *src++;
+
+ /* Trailing bits */
+ if (last)
+ *dst = comp(*src, *dst, last);
+ }
+ } else {
+ unsigned long d0, d1;
+ int m;
+
+ /* Different alignment for source and dest */
+ right = shift & (bits - 1);
+ left = -shift & (bits - 1);
+
+ if (dst_idx+n <= bits) {
+ /* Single destination word */
+ if (last)
+ first &= last;
+ if (shift > 0) {
+ /* Single source word */
+ *dst = comp(*src >> right, *dst, first);
+ } else if (src_idx+n <= bits) {
+ /* Single source word */
+ *dst = comp(*src << left, *dst, first);
+ } else {
+ /* 2 source words */
+ d0 = *src++;
+ d1 = *src;
+ *dst = comp(d0 << left | d1 >> right, *dst,
+ first);
+ }
+ } else {
+ /* Multiple destination words */
+ /** We must always remember the last value read,
+ because in case SRC and DST overlap bitwise (e.g.
+ when moving just one pixel in 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'. */
+ d0 = *src++;
+ /* Leading bits */
+ if (shift > 0) {
+ /* Single source word */
+ *dst = comp(d0 >> right, *dst, first);
+ dst++;
+ n -= bits - dst_idx;
+ } else {
+ /* 2 source words */
+ d1 = *src++;
+ *dst = comp(d0 << left | *dst >> right, *dst, first);
+ d0 = d1;
+ dst++;
+ n -= bits - dst_idx;
+ }
+
+ /* Main chunk */
+ m = n % bits;
+ n /= bits;
+ while (n >= 4) {
+ d1 = *src++;
+ *dst++ = d0 << left | d1 >> right;
+ d0 = d1;
+ d1 = *src++;
+ *dst++ = d0 << left | d1 >> right;
+ d0 = d1;
+ d1 = *src++;
+ *dst++ = d0 << left | d1 >> right;
+ d0 = d1;
+ d1 = *src++;
+ *dst++ = d0 << left | d1 >> right;
+ d0 = d1;
+ n -= 4;
+ }
+ while (n--) {
+ d1 = *src++;
+ *dst++ = d0 << left | d1 >> right;
+ d0 = d1;
+ }
+
+ /* Trailing bits */
+ if (last) {
+ if (m <= right) {
+ /* Single source word */
+ *dst = comp(d0 << left, *dst, last);
+ } else {
+ /* 2 source words */
+ d1 = *src;
+ *dst = comp(d0 << left | d1 >> right,
+ *dst, last);
+ }
+ }
+ }
+ }
+}
+
+ /*
+ * Generic bitwise copy algorithm, operating backward
+ */
+
+static void
+bitcpy_rev(unsigned long *dst, int dst_idx, const unsigned long *src,
+ int src_idx, int bits, unsigned n)
+{
+ unsigned long first, last;
+ int shift;
+
+ dst += (n-1)/bits;
+ src += (n-1)/bits;
+ if ((n-1) % bits) {
+ dst_idx += (n-1) % bits;
+ dst += dst_idx >> (ffs(bits) - 1);
+ dst_idx &= bits - 1;
+ src_idx += (n-1) % bits;
+ src += src_idx >> (ffs(bits) - 1);
+ src_idx &= bits - 1;
+ }
+
+ shift = dst_idx-src_idx;
+
+ 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 */
+ if ((unsigned long)dst_idx+1 >= n) {
+ /* Single word */
+ if (last)
+ first &= last;
+ *dst = comp(*src, *dst, first);
+ } else {
+ /* Multiple destination words */
+
+ /* Leading bits */
+ if (first != ~0UL) {
+ *dst = comp(*src, *dst, first);
+ dst--;
+ src--;
+ n -= dst_idx+1;
+ }
+
+ /* Main chunk */
+ n /= bits;
+ while (n >= 8) {
+ *dst-- = *src--;
+ *dst-- = *src--;
+ *dst-- = *src--;
+ *dst-- = *src--;
+ *dst-- = *src--;
+ *dst-- = *src--;
+ *dst-- = *src--;
+ *dst-- = *src--;
+ n -= 8;
+ }
+ while (n--)
+ *dst-- = *src--;
+ /* Trailing bits */
+ if (last)
+ *dst = comp(*src, *dst, last);
+ }
+ } else {
+ /* Different alignment for source and dest */
+
+ int const left = -shift & (bits-1);
+ int const right = shift & (bits-1);
+
+ if ((unsigned long)dst_idx+1 >= n) {
+ /* Single destination word */
+ if (last)
+ first &= last;
+ if (shift < 0) {
+ /* Single source word */
+ *dst = comp(*src << left, *dst, first);
+ } else if (1+(unsigned long)src_idx >= n) {
+ /* Single source word */
+ *dst = comp(*src >> right, *dst, first);
+ } else {
+ /* 2 source words */
+ *dst = comp(*src >> right | *(src-1) << left,
+ *dst, first);
+ }
+ } else {
+ /* Multiple destination words */
+ /** We must always remember the last value read,
+ because in case SRC and DST overlap bitwise (e.g.
+ when moving just one pixel in 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 = *src--;
+ /* Leading bits */
+ if (shift < 0) {
+ /* Single source word */
+ *dst = comp(d0 << left, *dst, first);
+ } else {
+ /* 2 source words */
+ d1 = *src--;
+ *dst = comp(d0 >> right | d1 << left, *dst,
+ first);
+ d0 = d1;
+ }
+ dst--;
+ n -= dst_idx+1;
+
+ /* Main chunk */
+ m = n % bits;
+ n /= bits;
+ while (n >= 4) {
+ d1 = *src--;
+ *dst-- = d0 >> right | d1 << left;
+ d0 = d1;
+ d1 = *src--;
+ *dst-- = d0 >> right | d1 << left;
+ d0 = d1;
+ d1 = *src--;
+ *dst-- = d0 >> right | d1 << left;
+ d0 = d1;
+ d1 = *src--;
+ *dst-- = d0 >> right | d1 << left;
+ d0 = d1;
+ n -= 4;
+ }
+ while (n--) {
+ d1 = *src--;
+ *dst-- = d0 >> right | d1 << left;
+ d0 = d1;
+ }
+
+ /* Trailing bits */
+ if (last) {
+ if (m <= left) {
+ /* Single source word */
+ *dst = comp(d0 >> right, *dst, last);
+ } else {
+ /* 2 source words */
+ d1 = *src;
+ *dst = comp(d0 >> right | d1 << left,
+ *dst, last);
+ }
+ }
+ }
+ }
+}
+
+void sys_copyarea(struct fb_info *p, const struct fb_copyarea *area)
+{
+ u32 dx = area->dx, dy = area->dy, sx = area->sx, sy = area->sy;
+ u32 height = area->height, width = area->width;
+ unsigned long const bits_per_line = p->fix.line_length*8u;
+ unsigned long *dst = NULL, *src = NULL;
+ int bits = BITS_PER_LONG, bytes = bits >> 3;
+ int dst_idx = 0, src_idx = 0, rev_copy = 0;
+
+ if (p->state != FBINFO_STATE_RUNNING)
+ return;
+
+ /* if the beginning of the target area might overlap with the end of
+ the source area, be have to copy the area reverse. */
+ if ((dy == sy && dx > sx) || (dy > sy)) {
+ dy += height;
+ sy += height;
+ rev_copy = 1;
+ }
+
+ /* split the base of the framebuffer into a long-aligned address and
+ the index of the first bit */
+ dst = src = (unsigned long *)((unsigned long)p->screen_base &
+ ~(bytes-1));
+ dst_idx = src_idx = 8*((unsigned long)p->screen_base & (bytes-1));
+ /* add offset of source and target area */
+ dst_idx += dy*bits_per_line + dx*p->var.bits_per_pixel;
+ src_idx += sy*bits_per_line + sx*p->var.bits_per_pixel;
+
+ if (p->fbops->fb_sync)
+ p->fbops->fb_sync(p);
+
+ if (rev_copy) {
+ while (height--) {
+ dst_idx -= bits_per_line;
+ src_idx -= bits_per_line;
+ dst += dst_idx >> (ffs(bits) - 1);
+ dst_idx &= (bytes - 1);
+ src += src_idx >> (ffs(bits) - 1);
+ src_idx &= (bytes - 1);
+ bitcpy_rev(dst, dst_idx, src, src_idx, bits,
+ width*p->var.bits_per_pixel);
+ }
+ } else {
+ while (height--) {
+ dst += dst_idx >> (ffs(bits) - 1);
+ dst_idx &= (bytes - 1);
+ src += src_idx >> (ffs(bits) - 1);
+ src_idx &= (bytes - 1);
+ bitcpy(dst, dst_idx, src, src_idx, bits,
+ width*p->var.bits_per_pixel);
+ dst_idx += bits_per_line;
+ src_idx += bits_per_line;
+ }
+ }
+}
+
+EXPORT_SYMBOL(sys_copyarea);
+
+MODULE_AUTHOR("Antonino Daplas <adaplas@pol.net>");
+MODULE_DESCRIPTION("Generic copyarea (sys-to-sys)");
+MODULE_LICENSE("GPL");
+