From: Miro Kropacek The SuperVidel graphics FPGA includes a hardware blitter (bit block transfer engine) operating within the SuperVidel DDR2 video RAM. Two versions of this blitter exist. Later versions (>= 9) of the SuperVidel firmware support an asynchronous command FIFO, older versions must be polled for command completion. Add hardware-accelerated copyarea, fillrect and imageblit fb operations (falling back to the non-accelerated versions for anything that exceeds blitter capabilities). Signed-off-by: Miro Kropacek Reviewed-by: Michael Schmitz Signed-off-by: Michael Schmitz Cc: Link: https://lists.debian.org/debian-68k/2026/08/msg00000.html --- Changes in v3: - adapt patch to fb_info -> *fb_info rewrite (in patch 2) --- drivers/video/fbdev/atafb.c | 197 ++++++++++++++++++++++++++++++++++++ 1 file changed, 197 insertions(+) diff --git a/drivers/video/fbdev/atafb.c b/drivers/video/fbdev/atafb.c index 1a245141560b..1e5724d99b39 100644 --- a/drivers/video/fbdev/atafb.c +++ b/drivers/video/fbdev/atafb.c @@ -2303,6 +2303,185 @@ static int ext_detect(struct fb_info *info) return 1; } +/* ------------------- SuperVidel SuperBlitter ---------------------- */ + +/* + * Hardware blitter in the SuperVidel FPGA, operating within SV DDR2 RAM. + * FW revision >= 9 provides a command FIFO (async operation); older + * revisions are programmed directly with busy-polling. + */ +#define SVBLIT_REGS_PHYS 0x80010000 +#define SVBLIT_SRC1 0x58 /* bits 26:0 */ +#define SVBLIT_SRC2 0x5c +#define SVBLIT_DST 0x60 +#define SVBLIT_COUNT 0x64 /* bytes per line - 1 */ +#define SVBLIT_SRC1_OFFSET 0x68 /* line start to next line start */ +#define SVBLIT_SRC2_OFFSET 0x6c +#define SVBLIT_DST_OFFSET 0x70 +#define SVBLIT_MASK_AND_LINES 0x74 /* bits 11:0: number of lines */ +#define SVBLIT_CONTROL 0x78 /* bit 0: busy/start, bits 4:1: mode */ +#define SVBLIT_VERSION 0x7c /* bits 9:0: FW revision */ +#define SVBLIT_FIFO 0x80 /* wr: data; rd: bit 0 empty, bit 1 full */ + +/* + * SuperBlitter bug: Instead of declared 2048 bytes, 2032 is the real maximum. + */ +#define SVBLIT_MAX_SPAN 2032 + +static void __iomem *svblit_regs; +static int svblit_fw; + +static inline u32 svblit_rd(unsigned int reg) +{ + return __raw_readl(svblit_regs + reg); +} + +static inline void svblit_wr(unsigned int reg, u32 val) +{ + __raw_writel(val, svblit_regs + reg); +} + +/* wait until all queued blits have finished */ +static void svblit_wait(void) +{ + if (svblit_fw >= 9) + /* FIFO empty flag = fewer than 9 longwords queued */ + while (!(svblit_rd(SVBLIT_FIFO) & 1)) + cpu_relax(); + while (svblit_rd(SVBLIT_CONTROL) & 1) + cpu_relax(); +} + +/* + * FW >= 9 queues commands through the 512-longword FIFO: a command is + * 9 longwords (registers 0x58..0x78 in order), executed whenever >= 9 + * words are queued and the blitter is idle. The full flag rises at + * >= 500 queued words, so below it there is always room for a whole + * command — one flag check per command prevents overflow (dropped + * words would desync the 9-word framing until an SV reinit, which is + * exactly what overflowing did before this guard existed). Older FW + * is programmed directly with busy-polling. + * + * The line byte count field is 11 bits but see SVBLIT_MAX_SPAN. + */ +static void svblit_copy(u32 src, u32 dst, u32 nbytes, u32 src_offset, + u32 dst_offset, u32 lines) +{ + while (nbytes) { + u32 chunk = min(nbytes, SVBLIT_MAX_SPAN); + + if (svblit_fw >= 9) { + while (svblit_rd(SVBLIT_FIFO) & 2) + cpu_relax(); + svblit_wr(SVBLIT_FIFO, src); + svblit_wr(SVBLIT_FIFO, 0); + svblit_wr(SVBLIT_FIFO, dst); + svblit_wr(SVBLIT_FIFO, chunk - 1); + svblit_wr(SVBLIT_FIFO, src_offset); + svblit_wr(SVBLIT_FIFO, 0); + svblit_wr(SVBLIT_FIFO, dst_offset); + svblit_wr(SVBLIT_FIFO, lines); + svblit_wr(SVBLIT_FIFO, 0x01); + } else { + while (svblit_rd(SVBLIT_CONTROL) & 1) + cpu_relax(); + svblit_wr(SVBLIT_SRC1, src); + svblit_wr(SVBLIT_SRC2, 0); + svblit_wr(SVBLIT_DST, dst); + svblit_wr(SVBLIT_COUNT, chunk - 1); + svblit_wr(SVBLIT_SRC1_OFFSET, src_offset); + svblit_wr(SVBLIT_SRC2_OFFSET, 0); + svblit_wr(SVBLIT_DST_OFFSET, dst_offset); + svblit_wr(SVBLIT_MASK_AND_LINES, lines); + svblit_wr(SVBLIT_CONTROL, 0x01); + } + + src += chunk; + dst += chunk; + nbytes -= chunk; + } +} + +static int svblit_sync(struct fb_info *info) +{ + svblit_wait(); + return 0; +} + +static void svblit_copyarea(struct fb_info *info, + const struct fb_copyarea *area) +{ + u32 bytespp = info->var.bits_per_pixel / 8; + u32 pitch = info->fix.line_length; + + /* + * The blitter walks lines in ascending order, so overlapping + * moves down/right would read already overwritten data. Those + * are rare for fbcon (scrolling backwards); leave them and + * oversized areas to the CPU. + */ + if (area->height > 4095 || + area->dy > area->sy || + (area->dy == area->sy && area->dx > area->sx)) { + svblit_wait(); + cfb_copyarea(info, area); + return; + } + + svblit_copy(external_addr + area->sy * pitch + area->sx * bytespp, + external_addr + area->dy * pitch + area->dx * bytespp, + area->width * bytespp, pitch, pitch, area->height); + /* async: every CPU access to the fb goes through svblit_wait() */ +} + +static void svblit_fillrect(struct fb_info *info, + const struct fb_fillrect *rect) +{ + u32 bytespp = info->var.bits_per_pixel / 8; + u32 pitch = info->fix.line_length; + u8 *line; + u32 pix; + + svblit_wait(); /* the CPU is about to touch the fb */ + + if (rect->rop != ROP_COPY || rect->height <= 1 || + rect->height > 4096) { + cfb_fillrect(info, rect); + return; + } + + pix = (info->fix.visual == FB_VISUAL_TRUECOLOR) ? + ((u32 *)info->pseudo_palette)[rect->color] : rect->color; + + /* draw the first line with the CPU ... */ + line = (u8 *)info->screen_base + rect->dy * pitch + + rect->dx * bytespp; + switch (bytespp) { + case 1: + memset(line, pix, rect->width); + break; + case 2: + memset16((u16 *)line, pix, rect->width); + break; + default: + memset32((u32 *)line, pix, rect->width); + break; + } + + /* ... and let the blitter replicate it into the other lines */ + svblit_copy(external_addr + rect->dy * pitch + rect->dx * bytespp, + external_addr + (rect->dy + 1) * pitch + + rect->dx * bytespp, + rect->width * bytespp, 0, pitch, rect->height - 1); +} + +static void svblit_imageblit(struct fb_info *info, + const struct fb_image *image) +{ + svblit_wait(); /* CPU rendering must not race queued blits */ + cfb_imageblit(info, image); +} + #endif /* ATAFB_EXT */ /* ------ This is the same for most hardware types -------- */ @@ -3179,6 +3358,24 @@ static int __init atafb_probe(struct platform_device *pdev) phys_screen_base = external_addr; screen_len = external_len & PAGE_MASK; memset (screen_base, 0, external_len); + + /* framebuffer in SV RAM: enable the SuperBlitter */ + if (external_addr >= 0xa0000000) { + svblit_regs = ioremap(SVBLIT_REGS_PHYS, 0x100); + if (svblit_regs) { + svblit_fw = svblit_rd(SVBLIT_VERSION) & 0x1ff; + atafb_ops.fb_fillrect = svblit_fillrect; + atafb_ops.fb_copyarea = svblit_copyarea; + atafb_ops.fb_imageblit = svblit_imageblit; + atafb_ops.fb_sync = svblit_sync; + fb_info->flags |= FBINFO_HWACCEL_COPYAREA | + FBINFO_HWACCEL_FILLRECT; + dev_info(&pdev->dev, + "SuperBlitter enabled, FW revision %d (%s)\n", + svblit_fw, svblit_fw >= 9 ? + "async FIFO" : "sync"); + } + } } #endif /* ATAFB_EXT */ -- 2.17.1