radeonfb: fix problem with color expansion & alignment

The engine on some radeon variants locks up if color expansion is called
for non aligned source data. This patch enables a feature of the core
fbdev to request aligned input pixmaps and uses the HW clipping engine to
clip the output to the requested size

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=11875

Signed-off-by: Benjamin Herrenschmidt <[e-mail]>
Tested-by: James Cloos <[e-mail]>
Cc: "Rafael J. Wysocki" <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: Krzysztof Helt <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/video/aty/radeon_accel.c

···
 				    const struct fb_image *image,
 				    u32 fg, u32 bg)
 {
-	unsigned int src_bytes, dwords;
+	unsigned int dwords;
 	u32 *bits;
 
 	radeonfb_set_creg(rinfo, DP_GUI_MASTER_CNTL, &rinfo->dp_gui_mc_cache,
 			  rinfo->dp_gui_mc_base |
-			  GMC_BRUSH_NONE |
+			  GMC_BRUSH_NONE | GMC_DST_CLIP_LEAVE |
 			  GMC_SRC_DATATYPE_MONO_FG_BG |
 			  ROP3_S |
 			  GMC_BYTE_ORDER_MSB_TO_LSB |
···
 			  DST_X_LEFT_TO_RIGHT | DST_Y_TOP_TO_BOTTOM);
 	radeonfb_set_creg(rinfo, DP_SRC_FRGD_CLR, &rinfo->dp_src_fg_cache, fg);
 	radeonfb_set_creg(rinfo, DP_SRC_BKGD_CLR, &rinfo->dp_src_bg_cache, bg);
-
-	radeon_fifo_wait(rinfo, 1);
-	OUTREG(DST_Y_X, (image->dy << 16) | image->dx);
 
 	/* Ensure the dst cache is flushed and the engine idle before
 	 * issuing the operation.
···
 
 	/* X here pads width to a multiple of 32 and uses the clipper to
 	 * adjust the result. Is that really necessary ? Things seem to
-	 * work ok for me without that and the doco doesn't seem to imply
+	 * work ok for me without that and the doco doesn't seem to imply]
 	 * there is such a restriction.
 	 */
-	OUTREG(DST_WIDTH_HEIGHT, (image->width << 16) | image->height);
+	radeon_fifo_wait(rinfo, 4);
+	OUTREG(SC_TOP_LEFT, (image->dy << 16) | image->dx);
+	OUTREG(SC_BOTTOM_RIGHT, ((image->dy + image->height) << 16) |
+	       (image->dx + image->width));
+	OUTREG(DST_Y_X, (image->dy << 16) | image->dx);
 
-	src_bytes = (((image->width * image->depth) + 7) / 8) * image->height;
-	dwords = (src_bytes + 3) / 4;
+	OUTREG(DST_HEIGHT_WIDTH, (image->height << 16) | ((image->width + 31) & ~31));
+
+	dwords = (image->width + 31) >> 5;
+	dwords *= image->height;
 	bits = (u32*)(image->data);
 
 	while(dwords >= 8) {

drivers/video/aty/radeon_base.c

···
 	info->fbops = &radeonfb_ops;
 	info->screen_base = rinfo->fb_base;
 	info->screen_size = rinfo->mapped_vram;
+
 	/* Fill fix common fields */
 	strlcpy(info->fix.id, rinfo->name, sizeof(info->fix.id));
         info->fix.smem_start = rinfo->fb_base_phys;
···
         info->fix.mmio_len = RADEON_REGSIZE;
 	info->fix.accel = FB_ACCEL_ATI_RADEON;
 
+	/* Allocate colormap */
 	fb_alloc_cmap(&info->cmap, 256, 0);
 
+	/* Setup pixmap used for acceleration */
+#define PIXMAP_SIZE	(2048 * 4)
+
+	info->pixmap.addr = kmalloc(PIXMAP_SIZE, GFP_KERNEL);
+	if (!info->pixmap.addr) {
+		printk(KERN_ERR "radeonfb: Failed to allocate pixmap !\n");
+		noaccel = 1;
+		goto bail;
+	}
+	info->pixmap.size = PIXMAP_SIZE;
+	info->pixmap.flags = FB_PIXMAP_SYSTEM;
+	info->pixmap.scan_align = 4;
+	info->pixmap.buf_align = 4;
+	info->pixmap.access_align = 32;
+
+bail:
 	if (noaccel)
 		info->flags |= FBINFO_HWACCEL_DISABLED;