stifb: Implement hardware accelerated copyarea

This patch adds hardware assisted scrolling. The code is based upon the
following investigation: https://parisc.wiki.kernel.org/index.php/NGLE#Blitter

A simple 'time ls -la /usr/bin' test shows 1.6x speed increase over soft
copy and 2.3x increase over FBINFO_READS_FAST (prefer soft copy over
screen redraw) on Artist framebuffer.

Signed-off-by: Alex Ivanov <[e-mail]>
Signed-off-by: Helge Deller <[e-mail]>

drivers/video/fbdev/stifb.c

···
 #define REG_3		0x0004a0
 #define REG_4		0x000600
 #define REG_6		0x000800
+#define REG_7		0x000804
 #define REG_8		0x000820
 #define REG_9		0x000a04
 #define REG_10		0x018000
···
 #define REG_21		0x200218
 #define REG_22		0x0005a0
 #define REG_23		0x0005c0
+#define REG_24		0x000808
+#define REG_25		0x000b00
 #define REG_26		0x200118
 #define REG_27		0x200308
 #define REG_32		0x21003c
···
 
 #define SET_LENXY_START_RECFILL(fb, lenxy) \
 	WRITE_WORD(lenxy, fb, REG_9)
+
+#define SETUP_COPYAREA(fb) \
+	WRITE_BYTE(0, fb, REG_16b1)
 
 static void
 HYPER_ENABLE_DISABLE_DISPLAY(struct stifb_info *fb, int enable)
···
 	return 0;
 }
 
+static void
+stifb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
+{
+	struct stifb_info *fb = container_of(info, struct stifb_info, info);
+
+	SETUP_COPYAREA(fb);
+
+	SETUP_HW(fb);
+	if (fb->info.var.bits_per_pixel == 32) {
+		WRITE_WORD(0xBBA0A000, fb, REG_10);
+
+		NGLE_REALLY_SET_IMAGE_PLANEMASK(fb, 0xffffffff);
+	} else {
+		WRITE_WORD(fb->id == S9000_ID_HCRX ? 0x13a02000 : 0x13a01000, fb, REG_10);
+
+		NGLE_REALLY_SET_IMAGE_PLANEMASK(fb, 0xff);
+	}
+
+	NGLE_QUICK_SET_IMAGE_BITMAP_OP(fb,
+		IBOvals(RopSrc, MaskAddrOffset(0),
+		BitmapExtent08, StaticReg(1),
+		DataDynamic, MaskOtc, BGx(0), FGx(0)));
+
+	WRITE_WORD(((area->sx << 16) | area->sy), fb, REG_24);
+	WRITE_WORD(((area->width << 16) | area->height), fb, REG_7);
+	WRITE_WORD(((area->dx << 16) | area->dy), fb, REG_25);
+
+	SETUP_FB(fb);
+}
+
 static void __init
 stifb_init_display(struct stifb_info *fb)
 {
···
 	.fb_setcolreg	= stifb_setcolreg,
 	.fb_blank	= stifb_blank,
 	.fb_fillrect	= cfb_fillrect,
-	.fb_copyarea	= cfb_copyarea,
+	.fb_copyarea	= stifb_copyarea,
 	.fb_imageblit	= cfb_imageblit,
 };
 
···
 	info->fbops = &stifb_ops;
 	info->screen_base = ioremap_nocache(REGION_BASE(fb,1), fix->smem_len);
 	info->screen_size = fix->smem_len;
-	info->flags = FBINFO_DEFAULT;
+	info->flags = FBINFO_DEFAULT | FBINFO_HWACCEL_COPYAREA;
 	info->pseudo_palette = &fb->pseudo_palette;
 
 	/* This has to be done !!! */