LinuxLists.cc - [PATCH 1/2] fb: add support for foreign endianness

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Subject: Re: [PATCH 1/2] fb: add support for foreign endianness

On Tue, Feb 05, 2008 at 06:44:32PM +0300, Anton Vorontsov wrote:
> This patch adds support for the framebuffers with non-native
> endianness. This is done via FBINFO_FOREIGN_ENDIAN flag that will
> be used by the drivers. Depending on the host endianness this flag
> will be overwritten by FBINFO_BE_MATH internal flag, or cleared.

Or better. Now introduce FB_FOREIGN_ENDIAN config option, so
fb_be_math() could be optimized away.

- - - -
From: Anton Vorontsov <[email protected]>
Subject: [PATCH] fb: add support for foreign endianness

This patch adds support for the framebuffers with non-native
endianness. This is done via FBINFO_FOREIGN_ENDIAN flag that will
be used by the drivers. Depending on the host endianness this flag
will be overwritten by FBINFO_BE_MATH internal flag, or cleared.

Tested to work on MPC8360E-RDK (BE) + Fujitsu MINT framebuffer (LE).

Signed-off-by: Anton Vorontsov <[email protected]>
---
drivers/video/Kconfig | 9 +++++++
drivers/video/cfbcopyarea.c | 23 ++++++++++--------
drivers/video/cfbfillrect.c | 48 +++++++++++++++++++++------------------
drivers/video/cfbimgblt.c | 52 +++++++++++++++++++++---------------------
drivers/video/fb_draw.h | 31 ++++++++++++++-----------
drivers/video/fbmem.c | 8 ++++++
drivers/video/syscopyarea.c | 20 ++++++++--------
drivers/video/sysfillrect.c | 49 ++++++++++++++++++++-------------------
drivers/video/sysimgblt.c | 47 ++++++++++++++++++--------------------
include/linux/fb.h | 36 ++++++++++++++++++++++-------
10 files changed, 183 insertions(+), 140 deletions(-)

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 758435f..6b3940d 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -139,6 +139,15 @@ config FB_SYS_IMAGEBLIT
blitting. This is used by drivers that don't provide their own
(accelerated) version and the framebuffer is in system RAM.

+config FB_FOREIGN_ENDIAN
+ bool "Enable support for foreign endianness"
+ depends on FB
+ ---help---
+ This option enables support for the framebuffers with non-native
+ endianness (e.g. Little-Endian framebuffer on a Big-Endian machine).
+ You probably don't have such hardware, so in most cases it's safe to
+ say "n" here.
+
config FB_SYS_FOPS
tristate
depends on FB
diff --git a/drivers/video/cfbcopyarea.c b/drivers/video/cfbcopyarea.c
index b07e419..df03f37 100644
--- a/drivers/video/cfbcopyarea.c
+++ b/drivers/video/cfbcopyarea.c
@@ -44,15 +44,16 @@
*/

static void
-bitcpy(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem *src,
- int src_idx, int bits, unsigned n, u32 bswapmask)
+bitcpy(struct fb_info *p, unsigned long __iomem *dst, int dst_idx,
+ const unsigned long __iomem *src, int src_idx, int bits,
+ unsigned n, u32 bswapmask)
{
unsigned long first, last;
int const shift = dst_idx-src_idx;
int left, right;

- first = fb_shifted_pixels_mask_long(dst_idx, bswapmask);
- last = ~fb_shifted_pixels_mask_long((dst_idx+n) % bits, bswapmask);
+ first = fb_shifted_pixels_mask_long(p, dst_idx, bswapmask);
+ last = ~fb_shifted_pixels_mask_long(p, (dst_idx+n) % bits, bswapmask);

if (!shift) {
// Same alignment for source and dest
@@ -202,8 +203,9 @@ bitcpy(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem *src
*/

static void
-bitcpy_rev(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem *src,
- int src_idx, int bits, unsigned n, u32 bswapmask)
+bitcpy_rev(struct fb_info *p, unsigned long __iomem *dst, int dst_idx,
+ const unsigned long __iomem *src, int src_idx, int bits,
+ unsigned n, u32 bswapmask)
{
unsigned long first, last;
int shift;
@@ -221,8 +223,9 @@ bitcpy_rev(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem

shift = dst_idx-src_idx;

- first = fb_shifted_pixels_mask_long(bits - 1 - dst_idx, bswapmask);
- last = ~fb_shifted_pixels_mask_long(bits - 1 - ((dst_idx-n) % bits), bswapmask);
+ first = fb_shifted_pixels_mask_long(p, bits - 1 - dst_idx, bswapmask);
+ last = ~fb_shifted_pixels_mask_long(p, bits - 1 - ((dst_idx-n) % bits),
+ bswapmask);

if (!shift) {
// Same alignment for source and dest
@@ -404,7 +407,7 @@ void cfb_copyarea(struct fb_info *p, const struct fb_copyarea *area)
dst_idx &= (bytes - 1);
src += src_idx >> (ffs(bits) - 1);
src_idx &= (bytes - 1);
- bitcpy_rev(dst, dst_idx, src, src_idx, bits,
+ bitcpy_rev(p, dst, dst_idx, src, src_idx, bits,
width*p->var.bits_per_pixel, bswapmask);
}
} else {
@@ -413,7 +416,7 @@ void cfb_copyarea(struct fb_info *p, const struct fb_copyarea *area)
dst_idx &= (bytes - 1);
src += src_idx >> (ffs(bits) - 1);
src_idx &= (bytes - 1);
- bitcpy(dst, dst_idx, src, src_idx, bits,
+ bitcpy(p, dst, dst_idx, src, src_idx, bits,
width*p->var.bits_per_pixel, bswapmask);
dst_idx += bits_per_line;
src_idx += bits_per_line;
diff --git a/drivers/video/cfbfillrect.c b/drivers/video/cfbfillrect.c
index 23d70a1..64b3576 100644
--- a/drivers/video/cfbfillrect.c
+++ b/drivers/video/cfbfillrect.c
@@ -36,16 +36,16 @@
*/

static void
-bitfill_aligned(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
- unsigned n, int bits, u32 bswapmask)
+bitfill_aligned(struct fb_info *p, unsigned long __iomem *dst, int dst_idx,
+ unsigned long pat, unsigned n, int bits, u32 bswapmask)
{
unsigned long first, last;

if (!n)
return;

- first = fb_shifted_pixels_mask_long(dst_idx, bswapmask);
- last = ~fb_shifted_pixels_mask_long((dst_idx+n) % bits, bswapmask);
+ first = fb_shifted_pixels_mask_long(p, dst_idx, bswapmask);
+ last = ~fb_shifted_pixels_mask_long(p, (dst_idx+n) % bits, bswapmask);

if (dst_idx+n <= bits) {
// Single word
@@ -93,16 +93,16 @@ bitfill_aligned(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
*/

static void
-bitfill_unaligned(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
- int left, int right, unsigned n, int bits)
+bitfill_unaligned(struct fb_info *p, unsigned long __iomem *dst, int dst_idx,
+ unsigned long pat, int left, int right, unsigned n, int bits)
{
unsigned long first, last;

if (!n)
return;

- first = FB_SHIFT_HIGH(~0UL, dst_idx);
- last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (dst_idx+n <= bits) {
// Single word
@@ -147,8 +147,9 @@ bitfill_unaligned(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
* Aligned pattern invert using 32/64-bit memory accesses
*/
static void
-bitfill_aligned_rev(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
- unsigned n, int bits, u32 bswapmask)
+bitfill_aligned_rev(struct fb_info *p, unsigned long __iomem *dst,
+ int dst_idx, unsigned long pat, unsigned n, int bits,
+ u32 bswapmask)
{
unsigned long val = pat, dat;
unsigned long first, last;
@@ -156,8 +157,8 @@ bitfill_aligned_rev(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
if (!n)
return;

- first = fb_shifted_pixels_mask_long(dst_idx, bswapmask);
- last = ~fb_shifted_pixels_mask_long((dst_idx+n) % bits, bswapmask);
+ first = fb_shifted_pixels_mask_long(p, dst_idx, bswapmask);
+ last = ~fb_shifted_pixels_mask_long(p, (dst_idx+n) % bits, bswapmask);

if (dst_idx+n <= bits) {
// Single word
@@ -217,16 +218,17 @@ bitfill_aligned_rev(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
*/

static void
-bitfill_unaligned_rev(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
- int left, int right, unsigned n, int bits)
+bitfill_unaligned_rev(struct fb_info *p, unsigned long __iomem *dst,
+ int dst_idx, unsigned long pat, int left, int right,
+ unsigned n, int bits)
{
unsigned long first, last, dat;

if (!n)
return;

- first = FB_SHIFT_HIGH(~0UL, dst_idx);
- last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (dst_idx+n <= bits) {
// Single word
@@ -306,7 +308,8 @@ void cfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
p->fbops->fb_sync(p);
if (!left) {
u32 bswapmask = fb_compute_bswapmask(p);
- void (*fill_op32)(unsigned long __iomem *dst, int dst_idx,
+ void (*fill_op32)(struct fb_info *p,
+ unsigned long __iomem *dst, int dst_idx,
unsigned long pat, unsigned n, int bits,
u32 bswapmask) = NULL;

@@ -325,16 +328,17 @@ void cfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
while (height--) {
dst += dst_idx >> (ffs(bits) - 1);
dst_idx &= (bits - 1);
- fill_op32(dst, dst_idx, pat, width*bpp, bits, bswapmask);
+ fill_op32(p, dst, dst_idx, pat, width*bpp, bits,
+ bswapmask);
dst_idx += p->fix.line_length*8;
}
} else {
int right;
int r;
int rot = (left-dst_idx) % bpp;
- void (*fill_op)(unsigned long __iomem *dst, int dst_idx,
- unsigned long pat, int left, int right,
- unsigned n, int bits) = NULL;
+ void (*fill_op)(struct fb_info *p, unsigned long __iomem *dst,
+ int dst_idx, unsigned long pat, int left,
+ int right, unsigned n, int bits) = NULL;

/* rotate pattern to correct start position */
pat = pat << rot | pat >> (bpp-rot);
@@ -355,7 +359,7 @@ void cfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
while (height--) {
dst += dst_idx >> (ffs(bits) - 1);
dst_idx &= (bits - 1);
- fill_op(dst, dst_idx, pat, left, right,
+ fill_op(p, dst, dst_idx, pat, left, right,
width*bpp, bits);
r = (p->fix.line_length*8) % bpp;
pat = pat << (bpp-r) | pat >> r;
diff --git a/drivers/video/cfbimgblt.c b/drivers/video/cfbimgblt.c
index f598907..ff3136b 100644
--- a/drivers/video/cfbimgblt.c
+++ b/drivers/video/cfbimgblt.c
@@ -43,30 +43,26 @@
#define DPRINTK(fmt, args...)
#endif

-static const u32 cfb_tab8[] = {
-#if defined(__BIG_ENDIAN)
+static const u32 cfb_tab8_be[] = {
0x00000000,0x000000ff,0x0000ff00,0x0000ffff,
0x00ff0000,0x00ff00ff,0x00ffff00,0x00ffffff,
0xff000000,0xff0000ff,0xff00ff00,0xff00ffff,
0xffff0000,0xffff00ff,0xffffff00,0xffffffff
-#elif defined(__LITTLE_ENDIAN)
+};
+
+static const u32 cfb_tab8_le[] = {
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)
+static const u32 cfb_tab16_be[] = {
0x00000000, 0x0000ffff, 0xffff0000, 0xffffffff
-#elif defined(__LITTLE_ENDIAN)
+};
+
+static const u32 cfb_tab16_le[] = {
0x00000000, 0xffff0000, 0x0000ffff, 0xffffffff
-#else
-#error FIXME: No endianness??
-#endif
};

static const u32 cfb_tab32[] = {
@@ -98,7 +94,8 @@ static inline void color_imageblit(const struct fb_image *image,
val = 0;

if (start_index) {
- u32 start_mask = ~fb_shifted_pixels_mask_u32(start_index, bswapmask);
+ u32 start_mask = ~fb_shifted_pixels_mask_u32(p,
+ start_index, bswapmask);
val = FB_READL(dst) & start_mask;
shift = start_index;
}
@@ -108,20 +105,21 @@ static inline void color_imageblit(const struct fb_image *image,
color = palette[*src];
else
color = *src;
- color <<= FB_LEFT_POS(bpp);
- val |= FB_SHIFT_HIGH(color, shift ^ bswapmask);
+ color <<= FB_LEFT_POS(p, bpp);
+ val |= FB_SHIFT_HIGH(p, color, shift ^ bswapmask);
if (shift >= null_bits) {
FB_WRITEL(val, dst++);

val = (shift == null_bits) ? 0 :
- FB_SHIFT_LOW(color, 32 - shift);
+ FB_SHIFT_LOW(p, color, 32 - shift);
}
shift += bpp;
shift &= (32 - 1);
src++;
}
if (shift) {
- u32 end_mask = fb_shifted_pixels_mask_u32(shift, bswapmask);
+ u32 end_mask = fb_shifted_pixels_mask_u32(p, shift,
+ bswapmask);

FB_WRITEL((FB_READL(dst) & end_mask) | val, dst);
}
@@ -152,8 +150,8 @@ static inline void slow_imageblit(const struct fb_image *image, struct fb_info *
u32 bswapmask = fb_compute_bswapmask(p);

dst2 = (u32 __iomem *) dst1;
- fgcolor <<= FB_LEFT_POS(bpp);
- bgcolor <<= FB_LEFT_POS(bpp);
+ fgcolor <<= FB_LEFT_POS(p, bpp);
+ bgcolor <<= FB_LEFT_POS(p, bpp);

for (i = image->height; i--; ) {
shift = val = 0;
@@ -164,7 +162,8 @@ static inline void slow_imageblit(const struct fb_image *image, struct fb_info *

/* write leading bits */
if (start_index) {
- u32 start_mask = ~fb_shifted_pixels_mask_u32(start_index, bswapmask);
+ u32 start_mask = ~fb_shifted_pixels_mask_u32(p,
+ start_index, bswapmask);
val = FB_READL(dst) & start_mask;
shift = start_index;
}
@@ -172,13 +171,13 @@ static inline void slow_imageblit(const struct fb_image *image, struct fb_info *
while (j--) {
l--;
color = (*s & (1 << l)) ? fgcolor : bgcolor;
- val |= FB_SHIFT_HIGH(color, shift ^ bswapmask);
+ val |= FB_SHIFT_HIGH(p, color, shift ^ bswapmask);

/* Did the bitshift spill bits to the next long? */
if (shift >= null_bits) {
FB_WRITEL(val, dst++);
val = (shift == null_bits) ? 0 :
- FB_SHIFT_LOW(color,32 - shift);
+ FB_SHIFT_LOW(p, color, 32 - shift);
}
shift += bpp;
shift &= (32 - 1);
@@ -187,7 +186,8 @@ static inline void slow_imageblit(const struct fb_image *image, struct fb_info *

/* write trailing bits */
if (shift) {
- u32 end_mask = fb_shifted_pixels_mask_u32(shift, bswapmask);
+ u32 end_mask = fb_shifted_pixels_mask_u32(p, shift,
+ bswapmask);

FB_WRITEL((FB_READL(dst) & end_mask) | val, dst);
}
@@ -223,13 +223,13 @@ static inline void fast_imageblit(const struct fb_image *image, struct fb_info *
u32 __iomem *dst;
const u32 *tab = NULL;
int i, j, k;
-
+
switch (bpp) {
case 8:
- tab = cfb_tab8;
+ tab = fb_be_math(p) ? cfb_tab8_be : cfb_tab8_le;
break;
case 16:
- tab = cfb_tab16;
+ tab = fb_be_math(p) ? cfb_tab16_be : cfb_tab16_le;
break;
case 32:
default:
diff --git a/drivers/video/fb_draw.h b/drivers/video/fb_draw.h
index a2a0618..1db6221 100644
--- a/drivers/video/fb_draw.h
+++ b/drivers/video/fb_draw.h
@@ -94,41 +94,44 @@ static inline unsigned long fb_rev_pixels_in_long(unsigned long val,
return val;
}

-static inline u32 fb_shifted_pixels_mask_u32(u32 index, u32 bswapmask)
+static inline u32 fb_shifted_pixels_mask_u32(struct fb_info *p, u32 index,
+ u32 bswapmask)
{
u32 mask;

if (!bswapmask) {
- mask = FB_SHIFT_HIGH(~(u32)0, index);
+ mask = FB_SHIFT_HIGH(p, ~(u32)0, index);
} else {
- mask = 0xff << FB_LEFT_POS(8);
- mask = FB_SHIFT_LOW(mask, index & (bswapmask)) & mask;
- mask = FB_SHIFT_HIGH(mask, index & ~(bswapmask));
+ mask = 0xff << FB_LEFT_POS(p, 8);
+ mask = FB_SHIFT_LOW(p, mask, index & (bswapmask)) & mask;
+ mask = FB_SHIFT_HIGH(p, mask, index & ~(bswapmask));
#if defined(__i386__) || defined(__x86_64__)
/* Shift argument is limited to 0 - 31 on x86 based CPU's */
if(index + bswapmask < 32)
#endif
- mask |= FB_SHIFT_HIGH(~(u32)0,
+ mask |= FB_SHIFT_HIGH(p, ~(u32)0,
(index + bswapmask) & ~(bswapmask));
}
return mask;
}

-static inline unsigned long fb_shifted_pixels_mask_long(u32 index, u32 bswapmask)
+static inline unsigned long fb_shifted_pixels_mask_long(struct fb_info *p,
+ u32 index,
+ u32 bswapmask)
{
unsigned long mask;

if (!bswapmask) {
- mask = FB_SHIFT_HIGH(~0UL, index);
+ mask = FB_SHIFT_HIGH(p, ~0UL, index);
} else {
- mask = 0xff << FB_LEFT_POS(8);
- mask = FB_SHIFT_LOW(mask, index & (bswapmask)) & mask;
- mask = FB_SHIFT_HIGH(mask, index & ~(bswapmask));
+ mask = 0xff << FB_LEFT_POS(p, 8);
+ mask = FB_SHIFT_LOW(p, mask, index & (bswapmask)) & mask;
+ mask = FB_SHIFT_HIGH(p, mask, index & ~(bswapmask));
#if defined(__i386__) || defined(__x86_64__)
/* Shift argument is limited to 0 - 31 on x86 based CPU's */
if(index + bswapmask < BITS_PER_LONG)
#endif
- mask |= FB_SHIFT_HIGH(~0UL,
+ mask |= FB_SHIFT_HIGH(p, ~0UL,
(index + bswapmask) & ~(bswapmask));
}
return mask;
@@ -158,8 +161,8 @@ static inline unsigned long fb_rev_pixels_in_long(unsigned long val,
return val;
}

-#define fb_shifted_pixels_mask_u32(i, b) FB_SHIFT_HIGH(~(u32)0, (i))
-#define fb_shifted_pixels_mask_long(i, b) FB_SHIFT_HIGH(~0UL, (i))
+#define fb_shifted_pixels_mask_u32(p, i, b) FB_SHIFT_HIGH((p), ~(u32)0, (i))
+#define fb_shifted_pixels_mask_long(p, i, b) FB_SHIFT_HIGH((p), ~0UL, (i))
#define fb_compute_bswapmask(...) 0

#endif /* CONFIG_FB_CFB_REV_PIXELS_IN_BYTE */
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index 1194f5e..c086004 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1368,6 +1368,7 @@ register_framebuffer(struct fb_info *fb_info)
int i;
struct fb_event event;
struct fb_videomode mode;
+ const bool foreign_endian = fb_info->flags & FBINFO_FOREIGN_ENDIAN;

if (num_registered_fb == FB_MAX)
return -ENXIO;
@@ -1404,6 +1405,13 @@ register_framebuffer(struct fb_info *fb_info)
if (!fb_info->pixmap.blit_y)
fb_info->pixmap.blit_y = ~(u32)0;

+ fb_info->flags &= ~FBINFO_FOREIGN_ENDIAN;
+#ifdef __BIG_ENDIAN
+ fb_info->flags |= foreign_endian ? 0 : FBINFO_BE_MATH;
+#else
+ fb_info->flags |= foreign_endian ? FBINFO_BE_MATH : 0;
+#endif
+
if (!fb_info->modelist.prev || !fb_info->modelist.next)
INIT_LIST_HEAD(&fb_info->modelist);

diff --git a/drivers/video/syscopyarea.c b/drivers/video/syscopyarea.c
index 37af10a..a352d5f 100644
--- a/drivers/video/syscopyarea.c
+++ b/drivers/video/syscopyarea.c
@@ -26,15 +26,15 @@
*/

static void
-bitcpy(unsigned long *dst, int dst_idx, const unsigned long *src,
- int src_idx, int bits, unsigned n)
+bitcpy(struct fb_info *p, 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));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (!shift) {
/* Same alignment for source and dest */
@@ -167,8 +167,8 @@ bitcpy(unsigned long *dst, int dst_idx, const unsigned long *src,
*/

static void
-bitcpy_rev(unsigned long *dst, int dst_idx, const unsigned long *src,
- int src_idx, int bits, unsigned n)
+bitcpy_rev(struct fb_info *p, unsigned long *dst, int dst_idx,
+ const unsigned long *src, int src_idx, int bits, unsigned n)
{
unsigned long first, last;
int shift;
@@ -186,8 +186,8 @@ bitcpy_rev(unsigned long *dst, int dst_idx, const unsigned long *src,

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)));
+ first = FB_SHIFT_LOW(p, ~0UL, bits - 1 - dst_idx);
+ last = ~(FB_SHIFT_LOW(p, ~0UL, bits - 1 - ((dst_idx-n) % bits)));

if (!shift) {
/* Same alignment for source and dest */
@@ -353,7 +353,7 @@ void sys_copyarea(struct fb_info *p, const struct fb_copyarea *area)
dst_idx &= (bytes - 1);
src += src_idx >> (ffs(bits) - 1);
src_idx &= (bytes - 1);
- bitcpy_rev(dst, dst_idx, src, src_idx, bits,
+ bitcpy_rev(p, dst, dst_idx, src, src_idx, bits,
width*p->var.bits_per_pixel);
}
} else {
@@ -362,7 +362,7 @@ void sys_copyarea(struct fb_info *p, const struct fb_copyarea *area)
dst_idx &= (bytes - 1);
src += src_idx >> (ffs(bits) - 1);
src_idx &= (bytes - 1);
- bitcpy(dst, dst_idx, src, src_idx, bits,
+ bitcpy(p, dst, dst_idx, src, src_idx, bits,
width*p->var.bits_per_pixel);
dst_idx += bits_per_line;
src_idx += bits_per_line;
diff --git a/drivers/video/sysfillrect.c b/drivers/video/sysfillrect.c
index a261e9e..f94d6b6 100644
--- a/drivers/video/sysfillrect.c
+++ b/drivers/video/sysfillrect.c
@@ -22,16 +22,16 @@
*/

static void
-bitfill_aligned(unsigned long *dst, int dst_idx, unsigned long pat,
- unsigned n, int bits)
+bitfill_aligned(struct fb_info *p, unsigned long *dst, int dst_idx,
+ unsigned long pat, unsigned n, int bits)
{
unsigned long first, last;

if (!n)
return;

- first = FB_SHIFT_HIGH(~0UL, dst_idx);
- last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (dst_idx+n <= bits) {
/* Single word */
@@ -78,16 +78,16 @@ bitfill_aligned(unsigned long *dst, int dst_idx, unsigned long pat,
*/

static void
-bitfill_unaligned(unsigned long *dst, int dst_idx, unsigned long pat,
- int left, int right, unsigned n, int bits)
+bitfill_unaligned(struct fb_info *p, unsigned long *dst, int dst_idx,
+ unsigned long pat, int left, int right, unsigned n, int bits)
{
unsigned long first, last;

if (!n)
return;

- first = FB_SHIFT_HIGH(~0UL, dst_idx);
- last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (dst_idx+n <= bits) {
/* Single word */
@@ -132,8 +132,8 @@ bitfill_unaligned(unsigned long *dst, int dst_idx, unsigned long pat,
* Aligned pattern invert using 32/64-bit memory accesses
*/
static void
-bitfill_aligned_rev(unsigned long *dst, int dst_idx, unsigned long pat,
- unsigned n, int bits)
+bitfill_aligned_rev(struct fb_info *p, unsigned long *dst, int dst_idx,
+ unsigned long pat, unsigned n, int bits)
{
unsigned long val = pat;
unsigned long first, last;
@@ -141,8 +141,8 @@ bitfill_aligned_rev(unsigned long *dst, int dst_idx, unsigned long pat,
if (!n)
return;

- first = FB_SHIFT_HIGH(~0UL, dst_idx);
- last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (dst_idx+n <= bits) {
/* Single word */
@@ -188,16 +188,17 @@ bitfill_aligned_rev(unsigned long *dst, int dst_idx, unsigned long pat,
*/

static void
-bitfill_unaligned_rev(unsigned long *dst, int dst_idx, unsigned long pat,
- int left, int right, unsigned n, int bits)
+bitfill_unaligned_rev(struct fb_info *p, unsigned long *dst, int dst_idx,
+ unsigned long pat, int left, int right, unsigned n,
+ int bits)
{
unsigned long first, last;

if (!n)
return;

- first = FB_SHIFT_HIGH(~0UL, dst_idx);
- last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (dst_idx+n <= bits) {
/* Single word */
@@ -267,9 +268,9 @@ void sys_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
if (p->fbops->fb_sync)
p->fbops->fb_sync(p);
if (!left) {
- void (*fill_op32)(unsigned long *dst, int dst_idx,
- unsigned long pat, unsigned n, int bits) =
- NULL;
+ void (*fill_op32)(struct fb_info *p, unsigned long *dst,
+ int dst_idx, unsigned long pat, unsigned n,
+ int bits) = NULL;

switch (rect->rop) {
case ROP_XOR:
@@ -287,16 +288,16 @@ void sys_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
while (height--) {
dst += dst_idx >> (ffs(bits) - 1);
dst_idx &= (bits - 1);
- fill_op32(dst, dst_idx, pat, width*bpp, bits);
+ fill_op32(p, dst, dst_idx, pat, width*bpp, bits);
dst_idx += p->fix.line_length*8;
}
} else {
int right;
int r;
int rot = (left-dst_idx) % bpp;
- void (*fill_op)(unsigned long *dst, int dst_idx,
- unsigned long pat, int left, int right,
- unsigned n, int bits) = NULL;
+ void (*fill_op)(struct fb_info *p, unsigned long *dst,
+ int dst_idx, unsigned long pat, int left,
+ int right, unsigned n, int bits) = NULL;

/* rotate pattern to correct start position */
pat = pat << rot | pat >> (bpp-rot);
@@ -318,7 +319,7 @@ void sys_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
while (height--) {
dst += dst_idx >> (ffs(bits) - 1);
dst_idx &= (bits - 1);
- fill_op(dst, dst_idx, pat, left, right,
+ fill_op(p, dst, dst_idx, pat, left, right,
width*bpp, bits);
r = (p->fix.line_length*8) % bpp;
pat = pat << (bpp-r) | pat >> r;
diff --git a/drivers/video/sysimgblt.c b/drivers/video/sysimgblt.c
index bd7e7e9..88daa9b 100644
--- a/drivers/video/sysimgblt.c
+++ b/drivers/video/sysimgblt.c
@@ -23,30 +23,26 @@
#define DPRINTK(fmt, args...)
#endif

-static const u32 cfb_tab8[] = {
-#if defined(__BIG_ENDIAN)
+static const u32 cfb_tab8_be[] = {
0x00000000,0x000000ff,0x0000ff00,0x0000ffff,
0x00ff0000,0x00ff00ff,0x00ffff00,0x00ffffff,
0xff000000,0xff0000ff,0xff00ff00,0xff00ffff,
0xffff0000,0xffff00ff,0xffffff00,0xffffffff
-#elif defined(__LITTLE_ENDIAN)
+};
+
+static const u32 cfb_tab8_le[] = {
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)
+static const u32 cfb_tab16_be[] = {
0x00000000, 0x0000ffff, 0xffff0000, 0xffffffff
-#elif defined(__LITTLE_ENDIAN)
+};
+
+static const u32 cfb_tab16_le[] = {
0x00000000, 0xffff0000, 0x0000ffff, 0xffffffff
-#else
-#error FIXME: No endianness??
-#endif
};

static const u32 cfb_tab32[] = {
@@ -72,7 +68,7 @@ static void color_imageblit(const struct fb_image *image, struct fb_info *p,
val = 0;

if (start_index) {
- u32 start_mask = ~(FB_SHIFT_HIGH(~(u32)0,
+ u32 start_mask = ~(FB_SHIFT_HIGH(p, ~(u32)0,
start_index));
val = *dst & start_mask;
shift = start_index;
@@ -83,20 +79,20 @@ static void color_imageblit(const struct fb_image *image, struct fb_info *p,
color = palette[*src];
else
color = *src;
- color <<= FB_LEFT_POS(bpp);
- val |= FB_SHIFT_HIGH(color, shift);
+ color <<= FB_LEFT_POS(p, bpp);
+ val |= FB_SHIFT_HIGH(p, color, shift);
if (shift >= null_bits) {
*dst++ = val;

val = (shift == null_bits) ? 0 :
- FB_SHIFT_LOW(color, 32 - shift);
+ FB_SHIFT_LOW(p, color, 32 - shift);
}
shift += bpp;
shift &= (32 - 1);
src++;
}
if (shift) {
- u32 end_mask = FB_SHIFT_HIGH(~(u32)0, shift);
+ u32 end_mask = FB_SHIFT_HIGH(p, ~(u32)0, shift);

*dst &= end_mask;
*dst |= val;
@@ -125,8 +121,8 @@ static void slow_imageblit(const struct fb_image *image, struct fb_info *p,
u32 i, j, l;

dst2 = dst1;
- fgcolor <<= FB_LEFT_POS(bpp);
- bgcolor <<= FB_LEFT_POS(bpp);
+ fgcolor <<= FB_LEFT_POS(p, bpp);
+ bgcolor <<= FB_LEFT_POS(p, bpp);

for (i = image->height; i--; ) {
shift = val = 0;
@@ -137,7 +133,8 @@ static void slow_imageblit(const struct fb_image *image, struct fb_info *p,

/* write leading bits */
if (start_index) {
- u32 start_mask = ~(FB_SHIFT_HIGH(~(u32)0,start_index));
+ u32 start_mask = ~(FB_SHIFT_HIGH(p, ~(u32)0,
+ start_index));
val = *dst & start_mask;
shift = start_index;
}
@@ -145,13 +142,13 @@ static void slow_imageblit(const struct fb_image *image, struct fb_info *p,
while (j--) {
l--;
color = (*s & (1 << l)) ? fgcolor : bgcolor;
- val |= FB_SHIFT_HIGH(color, shift);
+ val |= FB_SHIFT_HIGH(p, 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);
+ FB_SHIFT_LOW(p, color, 32 - shift);
}
shift += bpp;
shift &= (32 - 1);
@@ -160,7 +157,7 @@ static void slow_imageblit(const struct fb_image *image, struct fb_info *p,

/* write trailing bits */
if (shift) {
- u32 end_mask = FB_SHIFT_HIGH(~(u32)0, shift);
+ u32 end_mask = FB_SHIFT_HIGH(p, ~(u32)0, shift);

*dst &= end_mask;
*dst |= val;
@@ -199,10 +196,10 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p,

switch (bpp) {
case 8:
- tab = cfb_tab8;
+ tab = fb_be_math(p) ? cfb_tab8_be : cfb_tab8_le;
break;
case 16:
- tab = cfb_tab16;
+ tab = fb_be_math(p) ? cfb_tab16_be : cfb_tab16_le;
break;
case 32:
default:
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 58c57a3..a067ed3 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -791,6 +791,17 @@ struct fb_tile_ops {
*/
#define FBINFO_MISC_ALWAYS_SETPAR 0x40000

+/*
+ * Host and GPU endianness differ.
+ */
+#define FBINFO_FOREIGN_ENDIAN 0x100000
+/*
+ * Big endian math. This is the same flags as above, but with different
+ * meaning, it is set by the fb subsystem depending FOREIGN_ENDIAN flag
+ * and host endianness. Drivers should not use this flag.
+ */
+#define FBINFO_BE_MATH 0x100000
+
struct fb_info {
int node;
int flags;
@@ -899,15 +910,11 @@ struct fb_info {

#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))
-#else
-#define FB_LEFT_POS(bpp) (0)
-#define FB_SHIFT_HIGH(val, bits) ((val) << (bits))
-#define FB_SHIFT_LOW(val, bits) ((val) >> (bits))
-#endif
+#define FB_LEFT_POS(p, bpp) (fb_be_math(p) ? (32 - (bpp)) : 0)
+#define FB_SHIFT_HIGH(p, val, bits) (fb_be_math(p) ? (val) >> (bits) : \
+ (val) << (bits))
+#define FB_SHIFT_LOW(p, val, bits) (fb_be_math(p) ? (val) << (bits) : \
+ (val) >> (bits))

/*
* `Generic' versions of the frame buffer device operations
@@ -970,6 +977,17 @@ extern void fb_deferred_io_cleanup(struct fb_info *info);
extern int fb_deferred_io_fsync(struct file *file, struct dentry *dentry,
int datasync);

+static inline bool fb_be_math(struct fb_info *info)
+{
+#if defined(CONFIG_FB_FOREIGN_ENDIAN)
+ return info->flags & FBINFO_BE_MATH;
+#elif defined(__BIG_ENDIAN)
+ return true;
+#else
+ return false;
+#endif
+}
+
/* drivers/video/fbsysfs.c */
extern struct fb_info *framebuffer_alloc(size_t size, struct device *dev);
extern void framebuffer_release(struct fb_info *info);
--
1.5.2.2

2008-02-15 06:52:50

by Andrew Morton

[permalink] [raw]

Subject: Re: [PATCH 1/2] fb: add support for foreign endianness

On Tue, 5 Feb 2008 18:44:32 +0300 Anton Vorontsov <[email protected]> wrote:

> This patch adds support for the framebuffers with non-native
> endianness. This is done via FBINFO_FOREIGN_ENDIAN flag that will
> be used by the drivers. Depending on the host endianness this flag
> will be overwritten by FBINFO_BE_MATH internal flag, or cleared.
>
> Tested to work on MPC8360E-RDK (BE) + Fujitsu MINT framebuffer (LE).

That's a pretty large patch to fbdev core, and Tony appears to have gone
offline again and you didn't cc the fbdev mailing list.

I fixed the third problem. Could the other fbdev developers please review
and comment on this?

Thanks.

Actually... should CONFIG_FB_FOREIGN_ENDIAN exist, or should this feature
be permanently enabled?

I'd like to at least queue a patch in -mm so that CONFIG_FB_FOREIGN_ENDIAN
is forced-on, so the code gets some runtime testing. Will that break
anything?

From: Anton Vorontsov <[email protected]>

Add support for the framebuffers with non-native endianness. This is done via
FBINFO_FOREIGN_ENDIAN flag that will be used by the drivers. Depending on the
host endianness this flag will be overwritten by FBINFO_BE_MATH internal flag,
or cleared.

Tested to work on MPC8360E-RDK (BE) + Fujitsu MINT framebuffer (LE).

Signed-off-by: Anton Vorontsov <[email protected]>
Cc: "Antonino A. Daplas" <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

drivers/video/Kconfig | 9 +++++
drivers/video/cfbcopyarea.c | 23 ++++++++-------
drivers/video/cfbfillrect.c | 48 +++++++++++++++++--------------
drivers/video/cfbimgblt.c | 52 +++++++++++++++++-----------------
drivers/video/fb_draw.h | 31 +++++++++++---------
drivers/video/fbmem.c | 8 +++++
drivers/video/syscopyarea.c | 20 ++++++-------
drivers/video/sysfillrect.c | 49 ++++++++++++++++----------------
drivers/video/sysimgblt.c | 47 ++++++++++++++----------------
include/linux/fb.h | 36 +++++++++++++++++------
10 files changed, 183 insertions(+), 140 deletions(-)

diff -puN drivers/video/Kconfig~fb-add-support-for-foreign-endianness drivers/video/Kconfig
--- a/drivers/video/Kconfig~fb-add-support-for-foreign-endianness
+++ a/drivers/video/Kconfig
@@ -139,6 +139,15 @@ config FB_SYS_IMAGEBLIT
blitting. This is used by drivers that don't provide their own
(accelerated) version and the framebuffer is in system RAM.

+config FB_FOREIGN_ENDIAN
+ bool "Enable support for foreign endianness"
+ depends on FB
+ ---help---
+ This option enables support for the framebuffers with non-native
+ endianness (e.g. Little-Endian framebuffer on a Big-Endian machine).
+ You probably don't have such hardware, so in most cases it's safe to
+ say "n" here.
+
config FB_SYS_FOPS
tristate
depends on FB
diff -puN drivers/video/cfbcopyarea.c~fb-add-support-for-foreign-endianness drivers/video/cfbcopyarea.c
--- a/drivers/video/cfbcopyarea.c~fb-add-support-for-foreign-endianness
+++ a/drivers/video/cfbcopyarea.c
@@ -44,15 +44,16 @@
*/

static void
-bitcpy(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem *src,
- int src_idx, int bits, unsigned n, u32 bswapmask)
+bitcpy(struct fb_info *p, unsigned long __iomem *dst, int dst_idx,
+ const unsigned long __iomem *src, int src_idx, int bits,
+ unsigned n, u32 bswapmask)
{
unsigned long first, last;
int const shift = dst_idx-src_idx;
int left, right;

- first = fb_shifted_pixels_mask_long(dst_idx, bswapmask);
- last = ~fb_shifted_pixels_mask_long((dst_idx+n) % bits, bswapmask);
+ first = fb_shifted_pixels_mask_long(p, dst_idx, bswapmask);
+ last = ~fb_shifted_pixels_mask_long(p, (dst_idx+n) % bits, bswapmask);

if (!shift) {
// Same alignment for source and dest
@@ -202,8 +203,9 @@ bitcpy(unsigned long __iomem *dst, int d
*/

static void
-bitcpy_rev(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem *src,
- int src_idx, int bits, unsigned n, u32 bswapmask)
+bitcpy_rev(struct fb_info *p, unsigned long __iomem *dst, int dst_idx,
+ const unsigned long __iomem *src, int src_idx, int bits,
+ unsigned n, u32 bswapmask)
{
unsigned long first, last;
int shift;
@@ -221,8 +223,9 @@ bitcpy_rev(unsigned long __iomem *dst, i

shift = dst_idx-src_idx;

- first = fb_shifted_pixels_mask_long(bits - 1 - dst_idx, bswapmask);
- last = ~fb_shifted_pixels_mask_long(bits - 1 - ((dst_idx-n) % bits), bswapmask);
+ first = fb_shifted_pixels_mask_long(p, bits - 1 - dst_idx, bswapmask);
+ last = ~fb_shifted_pixels_mask_long(p, bits - 1 - ((dst_idx-n) % bits),
+ bswapmask);

if (!shift) {
// Same alignment for source and dest
@@ -404,7 +407,7 @@ void cfb_copyarea(struct fb_info *p, con
dst_idx &= (bytes - 1);
src += src_idx >> (ffs(bits) - 1);
src_idx &= (bytes - 1);
- bitcpy_rev(dst, dst_idx, src, src_idx, bits,
+ bitcpy_rev(p, dst, dst_idx, src, src_idx, bits,
width*p->var.bits_per_pixel, bswapmask);
}
} else {
@@ -413,7 +416,7 @@ void cfb_copyarea(struct fb_info *p, con
dst_idx &= (bytes - 1);
src += src_idx >> (ffs(bits) - 1);
src_idx &= (bytes - 1);
- bitcpy(dst, dst_idx, src, src_idx, bits,
+ bitcpy(p, dst, dst_idx, src, src_idx, bits,
width*p->var.bits_per_pixel, bswapmask);
dst_idx += bits_per_line;
src_idx += bits_per_line;
diff -puN drivers/video/cfbfillrect.c~fb-add-support-for-foreign-endianness drivers/video/cfbfillrect.c
--- a/drivers/video/cfbfillrect.c~fb-add-support-for-foreign-endianness
+++ a/drivers/video/cfbfillrect.c
@@ -36,16 +36,16 @@
*/

static void
-bitfill_aligned(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
- unsigned n, int bits, u32 bswapmask)
+bitfill_aligned(struct fb_info *p, unsigned long __iomem *dst, int dst_idx,
+ unsigned long pat, unsigned n, int bits, u32 bswapmask)
{
unsigned long first, last;

if (!n)
return;

- first = fb_shifted_pixels_mask_long(dst_idx, bswapmask);
- last = ~fb_shifted_pixels_mask_long((dst_idx+n) % bits, bswapmask);
+ first = fb_shifted_pixels_mask_long(p, dst_idx, bswapmask);
+ last = ~fb_shifted_pixels_mask_long(p, (dst_idx+n) % bits, bswapmask);

if (dst_idx+n <= bits) {
// Single word
@@ -93,16 +93,16 @@ bitfill_aligned(unsigned long __iomem *d
*/

static void
-bitfill_unaligned(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
- int left, int right, unsigned n, int bits)
+bitfill_unaligned(struct fb_info *p, unsigned long __iomem *dst, int dst_idx,
+ unsigned long pat, int left, int right, unsigned n, int bits)
{
unsigned long first, last;

if (!n)
return;

- first = FB_SHIFT_HIGH(~0UL, dst_idx);
- last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (dst_idx+n <= bits) {
// Single word
@@ -147,8 +147,9 @@ bitfill_unaligned(unsigned long __iomem
* Aligned pattern invert using 32/64-bit memory accesses
*/
static void
-bitfill_aligned_rev(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
- unsigned n, int bits, u32 bswapmask)
+bitfill_aligned_rev(struct fb_info *p, unsigned long __iomem *dst,
+ int dst_idx, unsigned long pat, unsigned n, int bits,
+ u32 bswapmask)
{
unsigned long val = pat, dat;
unsigned long first, last;
@@ -156,8 +157,8 @@ bitfill_aligned_rev(unsigned long __iome
if (!n)
return;

- first = fb_shifted_pixels_mask_long(dst_idx, bswapmask);
- last = ~fb_shifted_pixels_mask_long((dst_idx+n) % bits, bswapmask);
+ first = fb_shifted_pixels_mask_long(p, dst_idx, bswapmask);
+ last = ~fb_shifted_pixels_mask_long(p, (dst_idx+n) % bits, bswapmask);

if (dst_idx+n <= bits) {
// Single word
@@ -217,16 +218,17 @@ bitfill_aligned_rev(unsigned long __iome
*/

static void
-bitfill_unaligned_rev(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
- int left, int right, unsigned n, int bits)
+bitfill_unaligned_rev(struct fb_info *p, unsigned long __iomem *dst,
+ int dst_idx, unsigned long pat, int left, int right,
+ unsigned n, int bits)
{
unsigned long first, last, dat;

if (!n)
return;

- first = FB_SHIFT_HIGH(~0UL, dst_idx);
- last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (dst_idx+n <= bits) {
// Single word
@@ -306,7 +308,8 @@ void cfb_fillrect(struct fb_info *p, con
p->fbops->fb_sync(p);
if (!left) {
u32 bswapmask = fb_compute_bswapmask(p);
- void (*fill_op32)(unsigned long __iomem *dst, int dst_idx,
+ void (*fill_op32)(struct fb_info *p,
+ unsigned long __iomem *dst, int dst_idx,
unsigned long pat, unsigned n, int bits,
u32 bswapmask) = NULL;

@@ -325,16 +328,17 @@ void cfb_fillrect(struct fb_info *p, con
while (height--) {
dst += dst_idx >> (ffs(bits) - 1);
dst_idx &= (bits - 1);
- fill_op32(dst, dst_idx, pat, width*bpp, bits, bswapmask);
+ fill_op32(p, dst, dst_idx, pat, width*bpp, bits,
+ bswapmask);
dst_idx += p->fix.line_length*8;
}
} else {
int right;
int r;
int rot = (left-dst_idx) % bpp;
- void (*fill_op)(unsigned long __iomem *dst, int dst_idx,
- unsigned long pat, int left, int right,
- unsigned n, int bits) = NULL;
+ void (*fill_op)(struct fb_info *p, unsigned long __iomem *dst,
+ int dst_idx, unsigned long pat, int left,
+ int right, unsigned n, int bits) = NULL;

/* rotate pattern to correct start position */
pat = pat << rot | pat >> (bpp-rot);
@@ -355,7 +359,7 @@ void cfb_fillrect(struct fb_info *p, con
while (height--) {
dst += dst_idx >> (ffs(bits) - 1);
dst_idx &= (bits - 1);
- fill_op(dst, dst_idx, pat, left, right,
+ fill_op(p, dst, dst_idx, pat, left, right,
width*bpp, bits);
r = (p->fix.line_length*8) % bpp;
pat = pat << (bpp-r) | pat >> r;
diff -puN drivers/video/cfbimgblt.c~fb-add-support-for-foreign-endianness drivers/video/cfbimgblt.c
--- a/drivers/video/cfbimgblt.c~fb-add-support-for-foreign-endianness
+++ a/drivers/video/cfbimgblt.c
@@ -43,30 +43,26 @@
#define DPRINTK(fmt, args...)
#endif

-static const u32 cfb_tab8[] = {
-#if defined(__BIG_ENDIAN)
+static const u32 cfb_tab8_be[] = {
0x00000000,0x000000ff,0x0000ff00,0x0000ffff,
0x00ff0000,0x00ff00ff,0x00ffff00,0x00ffffff,
0xff000000,0xff0000ff,0xff00ff00,0xff00ffff,
0xffff0000,0xffff00ff,0xffffff00,0xffffffff
-#elif defined(__LITTLE_ENDIAN)
+};
+
+static const u32 cfb_tab8_le[] = {
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)
+static const u32 cfb_tab16_be[] = {
0x00000000, 0x0000ffff, 0xffff0000, 0xffffffff
-#elif defined(__LITTLE_ENDIAN)
+};
+
+static const u32 cfb_tab16_le[] = {
0x00000000, 0xffff0000, 0x0000ffff, 0xffffffff
-#else
-#error FIXME: No endianness??
-#endif
};

static const u32 cfb_tab32[] = {
@@ -98,7 +94,8 @@ static inline void color_imageblit(const
val = 0;

if (start_index) {
- u32 start_mask = ~fb_shifted_pixels_mask_u32(start_index, bswapmask);
+ u32 start_mask = ~fb_shifted_pixels_mask_u32(p,
+ start_index, bswapmask);
val = FB_READL(dst) & start_mask;
shift = start_index;
}
@@ -108,20 +105,21 @@ static inline void color_imageblit(const
color = palette[*src];
else
color = *src;
- color <<= FB_LEFT_POS(bpp);
- val |= FB_SHIFT_HIGH(color, shift ^ bswapmask);
+ color <<= FB_LEFT_POS(p, bpp);
+ val |= FB_SHIFT_HIGH(p, color, shift ^ bswapmask);
if (shift >= null_bits) {
FB_WRITEL(val, dst++);

val = (shift == null_bits) ? 0 :
- FB_SHIFT_LOW(color, 32 - shift);
+ FB_SHIFT_LOW(p, color, 32 - shift);
}
shift += bpp;
shift &= (32 - 1);
src++;
}
if (shift) {
- u32 end_mask = fb_shifted_pixels_mask_u32(shift, bswapmask);
+ u32 end_mask = fb_shifted_pixels_mask_u32(p, shift,
+ bswapmask);

FB_WRITEL((FB_READL(dst) & end_mask) | val, dst);
}
@@ -152,8 +150,8 @@ static inline void slow_imageblit(const
u32 bswapmask = fb_compute_bswapmask(p);

dst2 = (u32 __iomem *) dst1;
- fgcolor <<= FB_LEFT_POS(bpp);
- bgcolor <<= FB_LEFT_POS(bpp);
+ fgcolor <<= FB_LEFT_POS(p, bpp);
+ bgcolor <<= FB_LEFT_POS(p, bpp);

for (i = image->height; i--; ) {
shift = val = 0;
@@ -164,7 +162,8 @@ static inline void slow_imageblit(const

/* write leading bits */
if (start_index) {
- u32 start_mask = ~fb_shifted_pixels_mask_u32(start_index, bswapmask);
+ u32 start_mask = ~fb_shifted_pixels_mask_u32(p,
+ start_index, bswapmask);
val = FB_READL(dst) & start_mask;
shift = start_index;
}
@@ -172,13 +171,13 @@ static inline void slow_imageblit(const
while (j--) {
l--;
color = (*s & (1 << l)) ? fgcolor : bgcolor;
- val |= FB_SHIFT_HIGH(color, shift ^ bswapmask);
+ val |= FB_SHIFT_HIGH(p, color, shift ^ bswapmask);

/* Did the bitshift spill bits to the next long? */
if (shift >= null_bits) {
FB_WRITEL(val, dst++);
val = (shift == null_bits) ? 0 :
- FB_SHIFT_LOW(color,32 - shift);
+ FB_SHIFT_LOW(p, color, 32 - shift);
}
shift += bpp;
shift &= (32 - 1);
@@ -187,7 +186,8 @@ static inline void slow_imageblit(const

/* write trailing bits */
if (shift) {
- u32 end_mask = fb_shifted_pixels_mask_u32(shift, bswapmask);
+ u32 end_mask = fb_shifted_pixels_mask_u32(p, shift,
+ bswapmask);

FB_WRITEL((FB_READL(dst) & end_mask) | val, dst);
}
@@ -223,13 +223,13 @@ static inline void fast_imageblit(const
u32 __iomem *dst;
const u32 *tab = NULL;
int i, j, k;
-
+
switch (bpp) {
case 8:
- tab = cfb_tab8;
+ tab = fb_be_math(p) ? cfb_tab8_be : cfb_tab8_le;
break;
case 16:
- tab = cfb_tab16;
+ tab = fb_be_math(p) ? cfb_tab16_be : cfb_tab16_le;
break;
case 32:
default:
diff -puN drivers/video/fb_draw.h~fb-add-support-for-foreign-endianness drivers/video/fb_draw.h
--- a/drivers/video/fb_draw.h~fb-add-support-for-foreign-endianness
+++ a/drivers/video/fb_draw.h
@@ -94,41 +94,44 @@ static inline unsigned long fb_rev_pixel
return val;
}

-static inline u32 fb_shifted_pixels_mask_u32(u32 index, u32 bswapmask)
+static inline u32 fb_shifted_pixels_mask_u32(struct fb_info *p, u32 index,
+ u32 bswapmask)
{
u32 mask;

if (!bswapmask) {
- mask = FB_SHIFT_HIGH(~(u32)0, index);
+ mask = FB_SHIFT_HIGH(p, ~(u32)0, index);
} else {
- mask = 0xff << FB_LEFT_POS(8);
- mask = FB_SHIFT_LOW(mask, index & (bswapmask)) & mask;
- mask = FB_SHIFT_HIGH(mask, index & ~(bswapmask));
+ mask = 0xff << FB_LEFT_POS(p, 8);
+ mask = FB_SHIFT_LOW(p, mask, index & (bswapmask)) & mask;
+ mask = FB_SHIFT_HIGH(p, mask, index & ~(bswapmask));
#if defined(__i386__) || defined(__x86_64__)
/* Shift argument is limited to 0 - 31 on x86 based CPU's */
if(index + bswapmask < 32)
#endif
- mask |= FB_SHIFT_HIGH(~(u32)0,
+ mask |= FB_SHIFT_HIGH(p, ~(u32)0,
(index + bswapmask) & ~(bswapmask));
}
return mask;
}

-static inline unsigned long fb_shifted_pixels_mask_long(u32 index, u32 bswapmask)
+static inline unsigned long fb_shifted_pixels_mask_long(struct fb_info *p,
+ u32 index,
+ u32 bswapmask)
{
unsigned long mask;

if (!bswapmask) {
- mask = FB_SHIFT_HIGH(~0UL, index);
+ mask = FB_SHIFT_HIGH(p, ~0UL, index);
} else {
- mask = 0xff << FB_LEFT_POS(8);
- mask = FB_SHIFT_LOW(mask, index & (bswapmask)) & mask;
- mask = FB_SHIFT_HIGH(mask, index & ~(bswapmask));
+ mask = 0xff << FB_LEFT_POS(p, 8);
+ mask = FB_SHIFT_LOW(p, mask, index & (bswapmask)) & mask;
+ mask = FB_SHIFT_HIGH(p, mask, index & ~(bswapmask));
#if defined(__i386__) || defined(__x86_64__)
/* Shift argument is limited to 0 - 31 on x86 based CPU's */
if(index + bswapmask < BITS_PER_LONG)
#endif
- mask |= FB_SHIFT_HIGH(~0UL,
+ mask |= FB_SHIFT_HIGH(p, ~0UL,
(index + bswapmask) & ~(bswapmask));
}
return mask;
@@ -158,8 +161,8 @@ static inline unsigned long fb_rev_pixel
return val;
}

-#define fb_shifted_pixels_mask_u32(i, b) FB_SHIFT_HIGH(~(u32)0, (i))
-#define fb_shifted_pixels_mask_long(i, b) FB_SHIFT_HIGH(~0UL, (i))
+#define fb_shifted_pixels_mask_u32(p, i, b) FB_SHIFT_HIGH((p), ~(u32)0, (i))
+#define fb_shifted_pixels_mask_long(p, i, b) FB_SHIFT_HIGH((p), ~0UL, (i))
#define fb_compute_bswapmask(...) 0

#endif /* CONFIG_FB_CFB_REV_PIXELS_IN_BYTE */
diff -puN drivers/video/fbmem.c~fb-add-support-for-foreign-endianness drivers/video/fbmem.c
--- a/drivers/video/fbmem.c~fb-add-support-for-foreign-endianness
+++ a/drivers/video/fbmem.c
@@ -1368,6 +1368,7 @@ register_framebuffer(struct fb_info *fb_
int i;
struct fb_event event;
struct fb_videomode mode;
+ const bool foreign_endian = fb_info->flags & FBINFO_FOREIGN_ENDIAN;

if (num_registered_fb == FB_MAX)
return -ENXIO;
@@ -1404,6 +1405,13 @@ register_framebuffer(struct fb_info *fb_
if (!fb_info->pixmap.blit_y)
fb_info->pixmap.blit_y = ~(u32)0;

+ fb_info->flags &= ~FBINFO_FOREIGN_ENDIAN;
+#ifdef __BIG_ENDIAN
+ fb_info->flags |= foreign_endian ? 0 : FBINFO_BE_MATH;
+#else
+ fb_info->flags |= foreign_endian ? FBINFO_BE_MATH : 0;
+#endif
+
if (!fb_info->modelist.prev || !fb_info->modelist.next)
INIT_LIST_HEAD(&fb_info->modelist);

diff -puN drivers/video/syscopyarea.c~fb-add-support-for-foreign-endianness drivers/video/syscopyarea.c
--- a/drivers/video/syscopyarea.c~fb-add-support-for-foreign-endianness
+++ a/drivers/video/syscopyarea.c
@@ -26,15 +26,15 @@
*/

static void
-bitcpy(unsigned long *dst, int dst_idx, const unsigned long *src,
- int src_idx, int bits, unsigned n)
+bitcpy(struct fb_info *p, 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));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (!shift) {
/* Same alignment for source and dest */
@@ -167,8 +167,8 @@ bitcpy(unsigned long *dst, int dst_idx,
*/

static void
-bitcpy_rev(unsigned long *dst, int dst_idx, const unsigned long *src,
- int src_idx, int bits, unsigned n)
+bitcpy_rev(struct fb_info *p, unsigned long *dst, int dst_idx,
+ const unsigned long *src, int src_idx, int bits, unsigned n)
{
unsigned long first, last;
int shift;
@@ -186,8 +186,8 @@ bitcpy_rev(unsigned long *dst, int dst_i

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)));
+ first = FB_SHIFT_LOW(p, ~0UL, bits - 1 - dst_idx);
+ last = ~(FB_SHIFT_LOW(p, ~0UL, bits - 1 - ((dst_idx-n) % bits)));

if (!shift) {
/* Same alignment for source and dest */
@@ -353,7 +353,7 @@ void sys_copyarea(struct fb_info *p, con
dst_idx &= (bytes - 1);
src += src_idx >> (ffs(bits) - 1);
src_idx &= (bytes - 1);
- bitcpy_rev(dst, dst_idx, src, src_idx, bits,
+ bitcpy_rev(p, dst, dst_idx, src, src_idx, bits,
width*p->var.bits_per_pixel);
}
} else {
@@ -362,7 +362,7 @@ void sys_copyarea(struct fb_info *p, con
dst_idx &= (bytes - 1);
src += src_idx >> (ffs(bits) - 1);
src_idx &= (bytes - 1);
- bitcpy(dst, dst_idx, src, src_idx, bits,
+ bitcpy(p, dst, dst_idx, src, src_idx, bits,
width*p->var.bits_per_pixel);
dst_idx += bits_per_line;
src_idx += bits_per_line;
diff -puN drivers/video/sysfillrect.c~fb-add-support-for-foreign-endianness drivers/video/sysfillrect.c
--- a/drivers/video/sysfillrect.c~fb-add-support-for-foreign-endianness
+++ a/drivers/video/sysfillrect.c
@@ -22,16 +22,16 @@
*/

static void
-bitfill_aligned(unsigned long *dst, int dst_idx, unsigned long pat,
- unsigned n, int bits)
+bitfill_aligned(struct fb_info *p, unsigned long *dst, int dst_idx,
+ unsigned long pat, unsigned n, int bits)
{
unsigned long first, last;

if (!n)
return;

- first = FB_SHIFT_HIGH(~0UL, dst_idx);
- last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (dst_idx+n <= bits) {
/* Single word */
@@ -78,16 +78,16 @@ bitfill_aligned(unsigned long *dst, int
*/

static void
-bitfill_unaligned(unsigned long *dst, int dst_idx, unsigned long pat,
- int left, int right, unsigned n, int bits)
+bitfill_unaligned(struct fb_info *p, unsigned long *dst, int dst_idx,
+ unsigned long pat, int left, int right, unsigned n, int bits)
{
unsigned long first, last;

if (!n)
return;

- first = FB_SHIFT_HIGH(~0UL, dst_idx);
- last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (dst_idx+n <= bits) {
/* Single word */
@@ -132,8 +132,8 @@ bitfill_unaligned(unsigned long *dst, in
* Aligned pattern invert using 32/64-bit memory accesses
*/
static void
-bitfill_aligned_rev(unsigned long *dst, int dst_idx, unsigned long pat,
- unsigned n, int bits)
+bitfill_aligned_rev(struct fb_info *p, unsigned long *dst, int dst_idx,
+ unsigned long pat, unsigned n, int bits)
{
unsigned long val = pat;
unsigned long first, last;
@@ -141,8 +141,8 @@ bitfill_aligned_rev(unsigned long *dst,
if (!n)
return;

- first = FB_SHIFT_HIGH(~0UL, dst_idx);
- last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (dst_idx+n <= bits) {
/* Single word */
@@ -188,16 +188,17 @@ bitfill_aligned_rev(unsigned long *dst,
*/

static void
-bitfill_unaligned_rev(unsigned long *dst, int dst_idx, unsigned long pat,
- int left, int right, unsigned n, int bits)
+bitfill_unaligned_rev(struct fb_info *p, unsigned long *dst, int dst_idx,
+ unsigned long pat, int left, int right, unsigned n,
+ int bits)
{
unsigned long first, last;

if (!n)
return;

- first = FB_SHIFT_HIGH(~0UL, dst_idx);
- last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
+ first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
+ last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

if (dst_idx+n <= bits) {
/* Single word */
@@ -267,9 +268,9 @@ void sys_fillrect(struct fb_info *p, con
if (p->fbops->fb_sync)
p->fbops->fb_sync(p);
if (!left) {
- void (*fill_op32)(unsigned long *dst, int dst_idx,
- unsigned long pat, unsigned n, int bits) =
- NULL;
+ void (*fill_op32)(struct fb_info *p, unsigned long *dst,
+ int dst_idx, unsigned long pat, unsigned n,
+ int bits) = NULL;

switch (rect->rop) {
case ROP_XOR:
@@ -287,16 +288,16 @@ void sys_fillrect(struct fb_info *p, con
while (height--) {
dst += dst_idx >> (ffs(bits) - 1);
dst_idx &= (bits - 1);
- fill_op32(dst, dst_idx, pat, width*bpp, bits);
+ fill_op32(p, dst, dst_idx, pat, width*bpp, bits);
dst_idx += p->fix.line_length*8;
}
} else {
int right;
int r;
int rot = (left-dst_idx) % bpp;
- void (*fill_op)(unsigned long *dst, int dst_idx,
- unsigned long pat, int left, int right,
- unsigned n, int bits) = NULL;
+ void (*fill_op)(struct fb_info *p, unsigned long *dst,
+ int dst_idx, unsigned long pat, int left,
+ int right, unsigned n, int bits) = NULL;

/* rotate pattern to correct start position */
pat = pat << rot | pat >> (bpp-rot);
@@ -318,7 +319,7 @@ void sys_fillrect(struct fb_info *p, con
while (height--) {
dst += dst_idx >> (ffs(bits) - 1);
dst_idx &= (bits - 1);
- fill_op(dst, dst_idx, pat, left, right,
+ fill_op(p, dst, dst_idx, pat, left, right,
width*bpp, bits);
r = (p->fix.line_length*8) % bpp;
pat = pat << (bpp-r) | pat >> r;
diff -puN drivers/video/sysimgblt.c~fb-add-support-for-foreign-endianness drivers/video/sysimgblt.c
--- a/drivers/video/sysimgblt.c~fb-add-support-for-foreign-endianness
+++ a/drivers/video/sysimgblt.c
@@ -23,30 +23,26 @@
#define DPRINTK(fmt, args...)
#endif

-static const u32 cfb_tab8[] = {
-#if defined(__BIG_ENDIAN)
+static const u32 cfb_tab8_be[] = {
0x00000000,0x000000ff,0x0000ff00,0x0000ffff,
0x00ff0000,0x00ff00ff,0x00ffff00,0x00ffffff,
0xff000000,0xff0000ff,0xff00ff00,0xff00ffff,
0xffff0000,0xffff00ff,0xffffff00,0xffffffff
-#elif defined(__LITTLE_ENDIAN)
+};
+
+static const u32 cfb_tab8_le[] = {
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)
+static const u32 cfb_tab16_be[] = {
0x00000000, 0x0000ffff, 0xffff0000, 0xffffffff
-#elif defined(__LITTLE_ENDIAN)
+};
+
+static const u32 cfb_tab16_le[] = {
0x00000000, 0xffff0000, 0x0000ffff, 0xffffffff
-#else
-#error FIXME: No endianness??
-#endif
};

static const u32 cfb_tab32[] = {
@@ -72,7 +68,7 @@ static void color_imageblit(const struct
val = 0;

if (start_index) {
- u32 start_mask = ~(FB_SHIFT_HIGH(~(u32)0,
+ u32 start_mask = ~(FB_SHIFT_HIGH(p, ~(u32)0,
start_index));
val = *dst & start_mask;
shift = start_index;
@@ -83,20 +79,20 @@ static void color_imageblit(const struct
color = palette[*src];
else
color = *src;
- color <<= FB_LEFT_POS(bpp);
- val |= FB_SHIFT_HIGH(color, shift);
+ color <<= FB_LEFT_POS(p, bpp);
+ val |= FB_SHIFT_HIGH(p, color, shift);
if (shift >= null_bits) {
*dst++ = val;

val = (shift == null_bits) ? 0 :
- FB_SHIFT_LOW(color, 32 - shift);
+ FB_SHIFT_LOW(p, color, 32 - shift);
}
shift += bpp;
shift &= (32 - 1);
src++;
}
if (shift) {
- u32 end_mask = FB_SHIFT_HIGH(~(u32)0, shift);
+ u32 end_mask = FB_SHIFT_HIGH(p, ~(u32)0, shift);

*dst &= end_mask;
*dst |= val;
@@ -125,8 +121,8 @@ static void slow_imageblit(const struct
u32 i, j, l;

dst2 = dst1;
- fgcolor <<= FB_LEFT_POS(bpp);
- bgcolor <<= FB_LEFT_POS(bpp);
+ fgcolor <<= FB_LEFT_POS(p, bpp);
+ bgcolor <<= FB_LEFT_POS(p, bpp);

for (i = image->height; i--; ) {
shift = val = 0;
@@ -137,7 +133,8 @@ static void slow_imageblit(const struct

/* write leading bits */
if (start_index) {
- u32 start_mask = ~(FB_SHIFT_HIGH(~(u32)0,start_index));
+ u32 start_mask = ~(FB_SHIFT_HIGH(p, ~(u32)0,
+ start_index));
val = *dst & start_mask;
shift = start_index;
}
@@ -145,13 +142,13 @@ static void slow_imageblit(const struct
while (j--) {
l--;
color = (*s & (1 << l)) ? fgcolor : bgcolor;
- val |= FB_SHIFT_HIGH(color, shift);
+ val |= FB_SHIFT_HIGH(p, 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);
+ FB_SHIFT_LOW(p, color, 32 - shift);
}
shift += bpp;
shift &= (32 - 1);
@@ -160,7 +157,7 @@ static void slow_imageblit(const struct

/* write trailing bits */
if (shift) {
- u32 end_mask = FB_SHIFT_HIGH(~(u32)0, shift);
+ u32 end_mask = FB_SHIFT_HIGH(p, ~(u32)0, shift);

*dst &= end_mask;
*dst |= val;
@@ -199,10 +196,10 @@ static void fast_imageblit(const struct

switch (bpp) {
case 8:
- tab = cfb_tab8;
+ tab = fb_be_math(p) ? cfb_tab8_be : cfb_tab8_le;
break;
case 16:
- tab = cfb_tab16;
+ tab = fb_be_math(p) ? cfb_tab16_be : cfb_tab16_le;
break;
case 32:
default:
diff -puN include/linux/fb.h~fb-add-support-for-foreign-endianness include/linux/fb.h
--- a/include/linux/fb.h~fb-add-support-for-foreign-endianness
+++ a/include/linux/fb.h
@@ -791,6 +791,17 @@ struct fb_tile_ops {
*/
#define FBINFO_MISC_ALWAYS_SETPAR 0x40000

+/*
+ * Host and GPU endianness differ.
+ */
+#define FBINFO_FOREIGN_ENDIAN 0x100000
+/*
+ * Big endian math. This is the same flags as above, but with different
+ * meaning, it is set by the fb subsystem depending FOREIGN_ENDIAN flag
+ * and host endianness. Drivers should not use this flag.
+ */
+#define FBINFO_BE_MATH 0x100000
+
struct fb_info {
int node;
int flags;
@@ -899,15 +910,11 @@ struct fb_info {

#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))
-#else
-#define FB_LEFT_POS(bpp) (0)
-#define FB_SHIFT_HIGH(val, bits) ((val) << (bits))
-#define FB_SHIFT_LOW(val, bits) ((val) >> (bits))
-#endif
+#define FB_LEFT_POS(p, bpp) (fb_be_math(p) ? (32 - (bpp)) : 0)
+#define FB_SHIFT_HIGH(p, val, bits) (fb_be_math(p) ? (val) >> (bits) : \
+ (val) << (bits))
+#define FB_SHIFT_LOW(p, val, bits) (fb_be_math(p) ? (val) << (bits) : \
+ (val) >> (bits))

/*
* `Generic' versions of the frame buffer device operations
@@ -970,6 +977,17 @@ extern void fb_deferred_io_cleanup(struc
extern int fb_deferred_io_fsync(struct file *file, struct dentry *dentry,
int datasync);

+static inline bool fb_be_math(struct fb_info *info)
+{
+#if defined(CONFIG_FB_FOREIGN_ENDIAN)
+ return info->flags & FBINFO_BE_MATH;
+#elif defined(__BIG_ENDIAN)
+ return true;
+#else
+ return false;
+#endif
+}
+
/* drivers/video/fbsysfs.c */
extern struct fb_info *framebuffer_alloc(size_t size, struct device *dev);
extern void framebuffer_release(struct fb_info *info);
_

2008-02-15 16:45:54

[permalink] [raw]

Subject: Re: [PATCH 1/2] fb: add support for foreign endianness

On Thu, Feb 14, 2008 at 10:49:42PM -0800, Andrew Morton wrote:
> On Tue, 5 Feb 2008 18:44:32 +0300 Anton Vorontsov <[email protected]> wrote:
>
> > This patch adds support for the framebuffers with non-native
> > endianness. This is done via FBINFO_FOREIGN_ENDIAN flag that will
> > be used by the drivers. Depending on the host endianness this flag
> > will be overwritten by FBINFO_BE_MATH internal flag, or cleared.
> >
> > Tested to work on MPC8360E-RDK (BE) + Fujitsu MINT framebuffer (LE).
>
> That's a pretty large patch to fbdev core,

Yes, but changes are mostly trivial. No insurance of typos and thinkos
though. OTOH, it survived my tests.

> and Tony appears to have gone
> offline again and you didn't cc the fbdev mailing list.

FRAMEBUFFER LAYER
P: Antonino Daplas
M: [email protected]
L: [email protected] (subscribers-only)

I'm lazy to subscribe on occasional patches. Yup, this is hardly
an excuse...

> I fixed the third problem. Could the other fbdev developers please review
> and comment on this?
>
> Thanks.
>
>
>
> Actually... should CONFIG_FB_FOREIGN_ENDIAN exist, or should this feature
> be permanently enabled?

It should not. Because with CONFIG_FB_FOREIGN_ENDIAN enabled, drawing
might be a little bit slower, because of external checks for endianness
(I didn't noticed any slowdown, but I guess it's still measurable if we
find some fb benchmark).

Thinking about it a little bit more, I believe we want to add a choice,
which exactly foreign endianness we want to compile-in. Then, if we're
pretty confident that particular BE machine uses only LE framebuffer,
gcc can optimize away endianness checks.

Patch on top of previous inlined here. With that patch, slowdown is
possible with CONFIG_FB_BOTH_ENDIAN option only, which is still
default if FOREIGN_ENDIAN is selected.

> I'd like to at least queue a patch in -mm so that CONFIG_FB_FOREIGN_ENDIAN
> is forced-on, so the code gets some runtime testing. Will that break
> anything?

Nope, it should not break anything, just possible fbconsole/tux drawing
slowdown.

Thanks,

- - - -
From: Anton Vorontsov <[email protected]>
Subject: fb: add support for choice foreign endianness

With this patch FB_FOREIGN_ENDIAN converted to menuconfig with the
choice inside: which type of foreign endianness we want to compile-in.

As a bonus, now fb subsystem will refuse to register framebuffer with
unsupported endianness, and will suggest a way to solve the problem.

[ on top of fb-add-support-for-foreign-endianness.patch ]

Signed-off-by: Anton Vorontsov <[email protected]>
---
drivers/video/Kconfig | 27 +++++++++++++++++++++------
drivers/video/fbmem.c | 38 ++++++++++++++++++++++++++++++--------
include/linux/fb.h | 14 +++++++++++---
3 files changed, 62 insertions(+), 17 deletions(-)

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 6b3940d..9e0b6ea 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -139,14 +139,29 @@ config FB_SYS_IMAGEBLIT
blitting. This is used by drivers that don't provide their own
(accelerated) version and the framebuffer is in system RAM.

-config FB_FOREIGN_ENDIAN
- bool "Enable support for foreign endianness"
+menuconfig FB_FOREIGN_ENDIAN
+ bool "Framebuffer foreign endianness support"
depends on FB
---help---
- This option enables support for the framebuffers with non-native
- endianness (e.g. Little-Endian framebuffer on a Big-Endian machine).
- You probably don't have such hardware, so in most cases it's safe to
- say "n" here.
+ This menu will let you enable support for the framebuffers with
+ non-native endianness (e.g. Little-Endian framebuffer on a
+ Big-Endian machine). Most probably you don't have such hardware,
+ so it's safe to say "n" here.
+
+choice
+ prompt "Choice endianness support"
+ depends on FB_FOREIGN_ENDIAN
+
+config FB_BOTH_ENDIAN
+ bool "Support for Big- and Little-Endian framebuffers"
+
+config FB_BIG_ENDIAN
+ bool "Support for Big-Endian framebuffers only"
+
+config FB_LITTLE_ENDIAN
+ bool "Support for Little-Endian framebuffers only"
+
+endchoice

config FB_SYS_FOPS
tristate
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index c086004..11d92fd 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1352,6 +1352,32 @@ static const struct file_operations fb_fops = {

struct class *fb_class;
EXPORT_SYMBOL(fb_class);
+
+static int fb_check_foreignness(struct fb_info *fi)
+{
+ const bool foreign_endian = fi->flags & FBINFO_FOREIGN_ENDIAN;
+
+ fi->flags &= ~FBINFO_FOREIGN_ENDIAN;
+
+#ifdef __BIG_ENDIAN
+ fi->flags |= foreign_endian ? 0 : FBINFO_BE_MATH;
+#else
+ fi->flags |= foreign_endian ? FBINFO_BE_MATH : 0;
+#endif /* __BIG_ENDIAN */
+
+ if (fi->flags & FBINFO_BE_MATH && !fb_be_math(fi)) {
+ pr_err("%s: enable CONFIG_FB_BIG_ENDIAN to "
+ "support this framebuffer\n", fi->fix.id);
+ return -ENOSYS;
+ } else if (!(fi->flags & FBINFO_BE_MATH) && fb_be_math(fi)) {
+ pr_err("%s: enable CONFIG_FB_LITTLE_ENDIAN to "
+ "support this framebuffer\n", fi->fix.id);
+ return -ENOSYS;
+ }
+
+ return 0;
+}
+
/**
* register_framebuffer - registers a frame buffer device
* @fb_info: frame buffer info structure
@@ -1368,10 +1394,13 @@ register_framebuffer(struct fb_info *fb_info)
int i;
struct fb_event event;
struct fb_videomode mode;
- const bool foreign_endian = fb_info->flags & FBINFO_FOREIGN_ENDIAN;

if (num_registered_fb == FB_MAX)
return -ENXIO;
+
+ if (fb_check_foreignness(fb_info))
+ return -ENOSYS;
+
num_registered_fb++;
for (i = 0 ; i < FB_MAX; i++)
if (!registered_fb[i])
@@ -1405,13 +1434,6 @@ register_framebuffer(struct fb_info *fb_info)
if (!fb_info->pixmap.blit_y)
fb_info->pixmap.blit_y = ~(u32)0;

- fb_info->flags &= ~FBINFO_FOREIGN_ENDIAN;
-#ifdef __BIG_ENDIAN
- fb_info->flags |= foreign_endian ? 0 : FBINFO_BE_MATH;
-#else
- fb_info->flags |= foreign_endian ? FBINFO_BE_MATH : 0;
-#endif
-
if (!fb_info->modelist.prev || !fb_info->modelist.next)
INIT_LIST_HEAD(&fb_info->modelist);

diff --git a/include/linux/fb.h b/include/linux/fb.h
index a067ed3..72295b0 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -979,13 +979,21 @@ extern int fb_deferred_io_fsync(struct file *file, struct dentry *dentry,

static inline bool fb_be_math(struct fb_info *info)
{
-#if defined(CONFIG_FB_FOREIGN_ENDIAN)
+#ifdef CONFIG_FB_FOREIGN_ENDIAN
+#if defined(CONFIG_FB_BOTH_ENDIAN)
return info->flags & FBINFO_BE_MATH;
-#elif defined(__BIG_ENDIAN)
+#elif defined(CONFIG_FB_BIG_ENDIAN)
+ return true;
+#elif defined(CONFIG_FB_LITTLE_ENDIAN)
+ return false;
+#endif /* CONFIG_FB_BOTH_ENDIAN */
+#else
+#ifdef __BIG_ENDIAN
return true;
#else
return false;
-#endif
+#endif /* __BIG_ENDIAN */
+#endif /* CONFIG_FB_FOREIGN_ENDIAN */
}

/* drivers/video/fbsysfs.c */
--
1.5.2.2

2008-02-16 11:50:35

[permalink] [raw]

Subject: Re: [PATCH 1/2] fb: add support for foreign endianness

On Tue, 2008-02-05 at 18:44 +0300, Anton Vorontsov wrote:
> This patch adds support for the framebuffers with non-native
> endianness. This is done via FBINFO_FOREIGN_ENDIAN flag that will
> be used by the drivers. Depending on the host endianness this flag
> will be overwritten by FBINFO_BE_MATH internal flag, or cleared.
>
> Tested to work on MPC8360E-RDK (BE) + Fujitsu MINT framebuffer (LE).

Good luck running X on that thing :-)

The base server seems to cope.. until you start using render operations
or that sort of things, and then things blow up. There's shitload of
stuff that seems to assume native fb endianness..

Ben.

2008-02-17 09:44:51

by Geert Uytterhoeven

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

On Fri, 15 Feb 2008, Anton Vorontsov wrote:
> On Thu, Feb 14, 2008 at 10:49:42PM -0800, Andrew Morton wrote:
> > On Tue, 5 Feb 2008 18:44:32 +0300 Anton Vorontsov <[email protected]> wrote:
> > > This patch adds support for the framebuffers with non-native
> > > endianness. This is done via FBINFO_FOREIGN_ENDIAN flag that will
> > > be used by the drivers. Depending on the host endianness this flag
> > > will be overwritten by FBINFO_BE_MATH internal flag, or cleared.
> > >
> > > Tested to work on MPC8360E-RDK (BE) + Fujitsu MINT framebuffer (LE).
> >
> > That's a pretty large patch to fbdev core,
>
> Yes, but changes are mostly trivial. No insurance of typos and thinkos
> though. OTOH, it survived my tests.
>
> > and Tony appears to have gone
> > offline again and you didn't cc the fbdev mailing list.
>
> FRAMEBUFFER LAYER
> P: Antonino Daplas
> M: [email protected]
> L: [email protected] (subscribers-only)
>
> I'm lazy to subscribe on occasional patches. Yup, this is hardly
> an excuse...

While linux-fbdev is subscribers-only, non-subscribers are not plainly
rejected, but moderated, so the casual patch/comment/question comes
through.

I'll cook up a patch for MAINTAINERS to clarify.

> > Actually... should CONFIG_FB_FOREIGN_ENDIAN exist, or should this feature
> > be permanently enabled?
>
> It should not. Because with CONFIG_FB_FOREIGN_ENDIAN enabled, drawing
> might be a little bit slower, because of external checks for endianness
> (I didn't noticed any slowdown, but I guess it's still measurable if we
> find some fb benchmark).

> > I'd like to at least queue a patch in -mm so that CONFIG_FB_FOREIGN_ENDIAN
> > is forced-on, so the code gets some runtime testing. Will that break
> > anything?
>
> Nope, it should not break anything, just possible fbconsole/tux drawing
> slowdown.

Tux drawing speed doesn't really matter, as it's done once only.
Console text drawing is different.

`time cat MAINTAINERS' is a good test. Of course, is most time is spent
in scrolling, you won't see much difference.

So probably we need a test file that contains lines of text interspersed
with `HOME' escape sequences, so we don't scroll?

> Thinking about it a little bit more, I believe we want to add a choice,
> which exactly foreign endianness we want to compile-in. Then, if we're
> pretty confident that particular BE machine uses only LE framebuffer,
> gcc can optimize away endianness checks.
>
> Patch on top of previous inlined here. With that patch, slowdown is
> possible with CONFIG_FB_BOTH_ENDIAN option only, which is still
> default if FOREIGN_ENDIAN is selected.
> With this patch FB_FOREIGN_ENDIAN converted to menuconfig with the
> choice inside: which type of foreign endianness we want to compile-in.
>

The notion of `FOREIGN_ENDIAN' is relative, as it depends on the
architecture you're compiling for.

Suppose you have a PCI graphics card with a frame buffer that's always
big endian. When compiling for a big endian platform, the driver won't
depend on FB_FOREIGN_ENDIAN. When compiling for a little endian
platform, it will.

Shouldn't we add LITTLE_ENDIAN and BIG_ENDIAN Kconfig vars first, just
like we have 64BIT?

> As a bonus, now fb subsystem will refuse to register framebuffer with
> unsupported endianness, and will suggest a way to solve the problem.

I'd like to handle this in Kconfig (cfr. above).

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

2008-02-18 07:48:18

by Krzysztof Helt

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

On Sun, 17 Feb 2008 10:44:32 +0100 (CET)
Geert Uytterhoeven <[email protected]> wrote:

> On Fri, 15 Feb 2008, Anton Vorontsov wrote:
> > On Thu, Feb 14, 2008 at 10:49:42PM -0800, Andrew Morton wrote:
> > > On Tue, 5 Feb 2008 18:44:32 +0300 Anton Vorontsov <[email protected]> wrote:

> > > Actually... should CONFIG_FB_FOREIGN_ENDIAN exist, or should this feature
> > > be permanently enabled?
> >
(...)
>
> The notion of `FOREIGN_ENDIAN' is relative, as it depends on the
> architecture you're compiling for.
>
> Suppose you have a PCI graphics card with a frame buffer that's always
> big endian. When compiling for a big endian platform, the driver won't
> depend on FB_FOREIGN_ENDIAN. When compiling for a little endian
> platform, it will.
>
> Shouldn't we add LITTLE_ENDIAN and BIG_ENDIAN Kconfig vars first, just
> like we have 64BIT?
>

I disagree here. The FOREIGN_ENDIAN is enough. It is determined only by
graphics chip endianess and CPU (arch) endianess.
I know two fb drivers which use endianess information (pm2fb and s3c2410fb).
Both resolve endianess at driver level. Actually, both handle it by setting special
bits so the graphics chip itself reorder bytes to transform foreign endianess.
I understand that this patch is for chips which cannot reorder bytes by themselves.

So the FOREIGN_ENDIANESS flag should be set by the driver if it is needed
(if the graphics chip is BE and CPU is LE a simple #ifdef will add the flag).

>
> I'd like to handle this in Kconfig (cfr. above).
>

Again, it is possible. It is enough to put one rule which enables
the FOREIGN_ENDIAN if the architecture endianess is "foreign"
for the driver. The advantage here is that it can be set only
for drivers which need it (as some driver can handle it without
this code). It should be hidden option set only internally if needed
(no user selectable).

I tested this patch on the s3c2410fb with disabled byte order
corrections by the graphics chip itself. It worked for 8-bit depth
but not for 16-bit depth (pixel position seemed ok but wrong tux'
colors). I will investigate. The s3c2410fb is BE and the kernel
was arm LE.

I would like to extend this patch to fb depths below 8-bit. The
s3c2410fb cannot handle this correctly with LE kernel.

Kind regards,
Krzysztof

----------------------------------------------------------------------
Masz ostatnia szanse !
Sprawdz >>> http://link.interia.pl/f1d02

2008-02-18 17:31:34

by Valdis Klētnieks

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

On Mon, 18 Feb 2008 08:18:47 +0100, Krzysztof Helt said:
> I know two fb drivers which use endianess information (pm2fb and s3c2410fb).
> Both resolve endianess at driver level. Actually, both handle it by setting special
> bits so the graphics chip itself reorder bytes to transform foreign endianess.
> I understand that this patch is for chips which cannot reorder bytes by themselves.

Does anybody know of such a chip that's actually available in the wild? Or are
we writing drivers for speculative possible chips?

Attachments:

(No filename) (226.00 B)

2008-02-18 17:37:58

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

On Mon, Feb 18, 2008 at 12:30:11PM -0500, [email protected] wrote:
> On Mon, 18 Feb 2008 08:18:47 +0100, Krzysztof Helt said:
> > I know two fb drivers which use endianess information (pm2fb and s3c2410fb).
> > Both resolve endianess at driver level. Actually, both handle it by setting special
> > bits so the graphics chip itself reorder bytes to transform foreign endianess.
> > I understand that this patch is for chips which cannot reorder bytes by themselves.
>
> Does anybody know of such a chip that's actually available in the wild?

LE Fujitsu mb86277 (MINT) on the BE MPC8360E.

--
Anton Vorontsov
email: [email protected]
backup email: [email protected]
irc://irc.freenode.net/bd2

2008-02-18 23:35:35

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

[email protected] schrieb:
> On Mon, 18 Feb 2008 08:18:47 +0100, Krzysztof Helt said:
>> I know two fb drivers which use endianess information (pm2fb and s3c2410fb).
>> Both resolve endianess at driver level. Actually, both handle it by setting special
>> bits so the graphics chip itself reorder bytes to transform foreign endianess.
>> I understand that this patch is for chips which cannot reorder bytes by themselves.
>
> Does anybody know of such a chip that's actually available in the wild? Or are
> we writing drivers for speculative possible chips?
>

I had troubles with the Silicon Motion SM501/SM502 endianess on PowerPC PCI vs. LocalBus.
The chip also has a register to swap endianess, but that seems to only affect some
LocalBus modes.
The current fb and X drivers are working, but when it comes to font
aliasing and hw-acceleration, the problems start to rise again...

Regards,

Clemens

2008-02-19 00:37:00

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

On Tue, 2008-02-19 at 00:35 +0100, Clemens Koller wrote:
> [email protected] schrieb:
> > On Mon, 18 Feb 2008 08:18:47 +0100, Krzysztof Helt said:
> >> I know two fb drivers which use endianess information (pm2fb and s3c2410fb).
> >> Both resolve endianess at driver level. Actually, both handle it by setting special
> >> bits so the graphics chip itself reorder bytes to transform foreign endianess.
> >> I understand that this patch is for chips which cannot reorder bytes by themselves.
> >
> > Does anybody know of such a chip that's actually available in the wild? Or are
> > we writing drivers for speculative possible chips?
> >
>
> I had troubles with the Silicon Motion SM501/SM502 endianess on PowerPC PCI vs. LocalBus.
> The chip also has a register to swap endianess, but that seems to only affect some
> LocalBus modes.
> The current fb and X drivers are working, but when it comes to font
> aliasing and hw-acceleration, the problems start to rise again...

Most "sane" gfx chips nowadays provide configurable surfaces that allow
to perform the swap when writing/reading from regions of the
framebuffer, with the ability to set a different swapper setting (based
on bit depth) per region.

Then there is also the risk that your PCI<->Localbus has been wired
improperly :-)

Ben.

2008-02-19 11:28:19

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

Benjamin Herrenschmidt schrieb:
> On Tue, 2008-02-19 at 00:35 +0100, Clemens Koller wrote:
>> [email protected] schrieb:
>>> On Mon, 18 Feb 2008 08:18:47 +0100, Krzysztof Helt said:
>>>> I know two fb drivers which use endianess information (pm2fb and s3c2410fb).
>>>> Both resolve endianess at driver level. Actually, both handle it by setting special
>>>> bits so the graphics chip itself reorder bytes to transform foreign endianess.
>>>> I understand that this patch is for chips which cannot reorder bytes by themselves.
>>> Does anybody know of such a chip that's actually available in the wild? Or are
>>> we writing drivers for speculative possible chips?
>>>
>> I had troubles with the Silicon Motion SM501/SM502 endianess on PowerPC PCI vs. LocalBus.
>> The chip also has a register to swap endianess, but that seems to only affect some
>> LocalBus modes.
>> The current fb and X drivers are working, but when it comes to font
>> aliasing and hw-acceleration, the problems start to rise again...
>
> Most "sane" gfx chips nowadays provide configurable surfaces that allow
> to perform the swap when writing/reading from regions of the
> framebuffer, with the ability to set a different swapper setting (based
> on bit depth) per region.

Most! But not the SM50x. I still hope I would be wrong here. :-(

> Then there is also the risk that your PCI<->Localbus has been wired
> improperly :-)

That's not an issue in my case. The SM50x can be connected to
either an PCI or some Local/CPU-whateverbus IF.
I.e. on the MPC85xx PowerPC, PCI and LocalBus are separate bussses.
If the sm501 is attached to the MPC85xx' PCI like any other video card,
the PCI config-space is can be accessed as usual, whereas the framebuffer
memory area is byte-swapped compared to other common video cards.

So, to get back on topic:
I would welcome endianess swapping in SW. Some architectures (PowerPC)
should also be able to do swapped-endian mmapping. I just haven't
had time for a closer look but it looks also interesting way to do it
that way.

Regards,

Clemens

2008-02-19 12:07:26

by Andrew Morton

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

On Tue, 19 Feb 2008 12:27:54 +0100 Clemens Koller <[email protected]> wrote:

> Benjamin Herrenschmidt schrieb:
> > On Tue, 2008-02-19 at 00:35 +0100, Clemens Koller wrote:
> >> [email protected] schrieb:
> >>> On Mon, 18 Feb 2008 08:18:47 +0100, Krzysztof Helt said:
> >>>> I know two fb drivers which use endianess information (pm2fb and s3c2410fb).
> >>>> Both resolve endianess at driver level. Actually, both handle it by setting special
> >>>> bits so the graphics chip itself reorder bytes to transform foreign endianess.
> >>>> I understand that this patch is for chips which cannot reorder bytes by themselves.
> >>> Does anybody know of such a chip that's actually available in the wild? Or are
> >>> we writing drivers for speculative possible chips?
> >>>
> >> I had troubles with the Silicon Motion SM501/SM502 endianess on PowerPC PCI vs. LocalBus.
> >> The chip also has a register to swap endianess, but that seems to only affect some
> >> LocalBus modes.
> >> The current fb and X drivers are working, but when it comes to font
> >> aliasing and hw-acceleration, the problems start to rise again...
> >
> > Most "sane" gfx chips nowadays provide configurable surfaces that allow
> > to perform the swap when writing/reading from regions of the
> > framebuffer, with the ability to set a different swapper setting (based
> > on bit depth) per region.
>
> Most! But not the SM50x. I still hope I would be wrong here. :-(
>
> > Then there is also the risk that your PCI<->Localbus has been wired
> > improperly :-)
>
> That's not an issue in my case. The SM50x can be connected to
> either an PCI or some Local/CPU-whateverbus IF.
> I.e. on the MPC85xx PowerPC, PCI and LocalBus are separate bussses.
> If the sm501 is attached to the MPC85xx' PCI like any other video card,
> the PCI config-space is can be accessed as usual, whereas the framebuffer
> memory area is byte-swapped compared to other common video cards.
>
> So, to get back on topic:
> I would welcome endianess swapping in SW. Some architectures (PowerPC)
> should also be able to do swapped-endian mmapping. I just haven't
> had time for a closer look but it looks also interesting way to do it
> that way.

Bizarrely, the original author of the patch (Anton) has fallen off the cc.
Could whoever did that please thwap himself?

Anyway, my head is now officially spinning. Did anyone actually have a
reason why we shouldn't proceed with Anton's patch?

2008-02-19 12:22:21

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

Andrew Morton schrieb:
> On Tue, 19 Feb 2008 12:27:54 +0100 Clemens Koller <[email protected]> wrote:
>> Benjamin Herrenschmidt schrieb:
>>> On Tue, 2008-02-19 at 00:35 +0100, Clemens Koller wrote:
>>>> [email protected] schrieb:
>>>>> On Mon, 18 Feb 2008 08:18:47 +0100, Krzysztof Helt said:
>>>>>> I know two fb drivers which use endianess information (pm2fb and s3c2410fb).
>>>>>> Both resolve endianess at driver level. Actually, both handle it by setting special
>>>>>> bits so the graphics chip itself reorder bytes to transform foreign endianess.
>>>>>> I understand that this patch is for chips which cannot reorder bytes by themselves.
>>>>> Does anybody know of such a chip that's actually available in the wild? Or are
>>>>> we writing drivers for speculative possible chips?
>>>>>
>>>> I had troubles with the Silicon Motion SM501/SM502 endianess on PowerPC PCI vs. LocalBus.
>>>> The chip also has a register to swap endianess, but that seems to only affect some
>>>> LocalBus modes.
>>>> The current fb and X drivers are working, but when it comes to font
>>>> aliasing and hw-acceleration, the problems start to rise again...
>>> Most "sane" gfx chips nowadays provide configurable surfaces that allow
>>> to perform the swap when writing/reading from regions of the
>>> framebuffer, with the ability to set a different swapper setting (based
>>> on bit depth) per region.
>> Most! But not the SM50x. I still hope I would be wrong here. :-(
>>
>>> Then there is also the risk that your PCI<->Localbus has been wired
>>> improperly :-)
>> That's not an issue in my case. The SM50x can be connected to
>> either an PCI or some Local/CPU-whateverbus IF.
>> I.e. on the MPC85xx PowerPC, PCI and LocalBus are separate bussses.
>> If the sm501 is attached to the MPC85xx' PCI like any other video card,
>> the PCI config-space is can be accessed as usual, whereas the framebuffer
>> memory area is byte-swapped compared to other common video cards.
>>
>> So, to get back on topic:
>> I would welcome endianess swapping in SW. Some architectures (PowerPC)
>> should also be able to do swapped-endian mmapping. I just haven't
>> had time for a closer look but it looks also interesting way to do it
>> that way.
>
> Bizarrely, the original author of the patch (Anton) has fallen off the cc.
> Could whoever did that please thwap himself?

Propably my bad, being subscribed to several CCed lists...

> Anyway, my head is now officially spinning. Did anyone actually have a
> reason why we shouldn't proceed with Anton's patch?

Since it seem that there are some odd chips out in the wild, I guess
Valdis (also readded to CC:) has no more objections to give it a try. :-)

Regards,

Clemens

2008-02-20 00:48:46

by Valdis Klētnieks

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

On Tue, 19 Feb 2008 04:05:30 PST, Andrew Morton said:
> On Tue, 19 Feb 2008 12:27:54 +0100 Clemens Koller <[email protected]
> wrote:
> > That's not an issue in my case. The SM50x can be connected to
> > either an PCI or some Local/CPU-whateverbus IF.
> > I.e. on the MPC85xx PowerPC, PCI and LocalBus are separate bussses.
> > If the sm501 is attached to the MPC85xx' PCI like any other video card,
> > the PCI config-space is can be accessed as usual, whereas the framebuffer
> > memory area is byte-swapped compared to other common video cards.

> Anyway, my head is now officially spinning. Did anyone actually have a
> reason why we shouldn't proceed with Anton's patch?

Clemens answered my question regarding the real-life existence of hardware
that would benefit. I'd say if Anton's patch works on Clemens' hardware and
otherwise passes review, we should proceed...

Attachments:

(No filename) (226.00 B)

2008-02-20 00:52:42

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

On Tue, 2008-02-19 at 19:47 -0500, [email protected] wrote:
> On Tue, 19 Feb 2008 04:05:30 PST, Andrew Morton said:
> > On Tue, 19 Feb 2008 12:27:54 +0100 Clemens Koller <[email protected]
> > wrote:
> > > That's not an issue in my case. The SM50x can be connected to
> > > either an PCI or some Local/CPU-whateverbus IF.
> > > I.e. on the MPC85xx PowerPC, PCI and LocalBus are separate bussses.
> > > If the sm501 is attached to the MPC85xx' PCI like any other video card,
> > > the PCI config-space is can be accessed as usual, whereas the framebuffer
> > > memory area is byte-swapped compared to other common video cards.
>
> > Anyway, my head is now officially spinning. Did anyone actually have a
> > reason why we shouldn't proceed with Anton's patch?
>
> Clemens answered my question regarding the real-life existence of hardware
> that would benefit. I'd say if Anton's patch works on Clemens' hardware and
> otherwise passes review, we should proceed...

No objection here neither.

Ben.

2008-02-20 00:57:45

by Paul Mackerras

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

Andrew Morton writes:

> Bizarrely, the original author of the patch (Anton) has fallen off the cc.
> Could whoever did that please thwap himself?
>
> Anyway, my head is now officially spinning. Did anyone actually have a
> reason why we shouldn't proceed with Anton's patch?

I was wondering if it would be sufficient to provide alternative
versions of fb_readl, fb_writel etc. that do byte-swapping. That
would mean that all framebuffers would have to have the same
endianness, but that would suffice for embedded systems such as
Anton's and would end up a lot simpler IMHO.

Paul.

2008-02-20 12:18:33

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

On Wed, Feb 20, 2008 at 11:56:35AM +1100, Paul Mackerras wrote:
> Andrew Morton writes:
>
> > Bizarrely, the original author of the patch (Anton) has fallen off the cc.
> > Could whoever did that please thwap himself?
> >
> > Anyway, my head is now officially spinning. Did anyone actually have a
> > reason why we shouldn't proceed with Anton's patch?
>
> I was wondering if it would be sufficient to provide alternative
> versions of fb_readl, fb_writel etc. that do byte-swapping.

This is of course viable alternative. And I was considering this, but
later I abandoned the idea: that way we'll end up doing math in the
native endianness and then converting it to the foreign. This feels
ugly in contrast when we can do the right math in the first place, per
framebuffer.

> That
> would mean that all framebuffers would have to have the same
> endianness,

Yup, another downside of changing the code to fix some narrow
problem. Plus, this means things will break if/when we'll attach
PCI video card into the MPC8360E-RDK.

Thanks,

--
Anton Vorontsov
email: [email protected]
backup email: [email protected]
irc://irc.freenode.net/bd2

2008-02-20 15:44:41

[permalink] [raw]

Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness

Paul Mackerras schrieb:
> Andrew Morton writes:
>
>> Bizarrely, the original author of the patch (Anton) has fallen off the cc.
>> Could whoever did that please thwap himself?
>>
>> Anyway, my head is now officially spinning. Did anyone actually have a
>> reason why we shouldn't proceed with Anton's patch?
>
> I was wondering if it would be sufficient to provide alternative
> versions of fb_readl, fb_writel etc. that do byte-swapping. That
> would mean that all framebuffers would have to have the same
> endianness, but that would suffice for embedded systems such as
> Anton's and would end up a lot simpler IMHO.

Yes. At least the affected PowerPC platforms can do byte-swapping on
the fly, so this should be sufficient and without performance
penalty, AFAICS.

Regards,

Clemens

2008-02-20 20:40:00