static void __init nubus_add_board()

in nubus.c [717:827]

• 65 lines of code
• 10 McCabe index (conditional complexity)

static void __init nubus_add_board(int slot, int bytelanes)
{
	struct nubus_board *board;
	unsigned char *rp;
	unsigned long dpat;
	struct nubus_dir dir;
	struct nubus_dirent ent;
	int prev_resid = -1;

	/* Move to the start of the format block */
	rp = nubus_rom_addr(slot);
	nubus_rewind(&rp, FORMAT_BLOCK_SIZE, bytelanes);

	/* Actually we should probably panic if this fails */
	if ((board = kzalloc(sizeof(*board), GFP_ATOMIC)) == NULL)
		return;
	board->fblock = rp;

	/* Dump the format block for debugging purposes */
	pr_debug("Slot %X, format block at 0x%p:\n", slot, rp);
	pr_debug("%08lx\n", nubus_get_rom(&rp, 4, bytelanes));
	pr_debug("%08lx\n", nubus_get_rom(&rp, 4, bytelanes));
	pr_debug("%08lx\n", nubus_get_rom(&rp, 4, bytelanes));
	pr_debug("%02lx\n", nubus_get_rom(&rp, 1, bytelanes));
	pr_debug("%02lx\n", nubus_get_rom(&rp, 1, bytelanes));
	pr_debug("%08lx\n", nubus_get_rom(&rp, 4, bytelanes));
	pr_debug("%02lx\n", nubus_get_rom(&rp, 1, bytelanes));
	pr_debug("%02lx\n", nubus_get_rom(&rp, 1, bytelanes));
	rp = board->fblock;

	board->slot = slot;
	board->slot_addr = (unsigned long)nubus_slot_addr(slot);
	board->doffset = nubus_get_rom(&rp, 4, bytelanes);
	/* rom_length is *supposed* to be the total length of the
	 * ROM.  In practice it is the "amount of ROM used to compute
	 * the CRC."  So some jokers decide to set it to zero and
	 * set the crc to zero so they don't have to do any math.
	 * See the Performa 460 ROM, for example.  Those Apple "engineers".
	 */
	board->rom_length = nubus_get_rom(&rp, 4, bytelanes);
	board->crc = nubus_get_rom(&rp, 4, bytelanes);
	board->rev = nubus_get_rom(&rp, 1, bytelanes);
	board->format = nubus_get_rom(&rp, 1, bytelanes);
	board->lanes = bytelanes;

	/* Directory offset should be small and negative... */
	if (!(board->doffset & 0x00FF0000))
		pr_warn("Slot %X: Dodgy doffset!\n", slot);
	dpat = nubus_get_rom(&rp, 4, bytelanes);
	if (dpat != NUBUS_TEST_PATTERN)
		pr_warn("Slot %X: Wrong test pattern %08lx!\n", slot, dpat);

	/*
	 *	I wonder how the CRC is meant to work -
	 *		any takers ?
	 * CSA: According to MAC docs, not all cards pass the CRC anyway,
	 * since the initial Macintosh ROM releases skipped the check.
	 */

	/* Set up the directory pointer */
	board->directory = board->fblock;
	nubus_move(&board->directory, nubus_expand32(board->doffset),
	           board->lanes);

	nubus_get_root_dir(board, &dir);

	/* We're ready to rock */
	pr_debug("Slot %X resources:\n", slot);

	/* Each slot should have one board resource and any number of
	 * functional resources.  So we'll fill in some fields in the
	 * struct nubus_board from the board resource, then walk down
	 * the list of functional resources, spinning out a nubus_rsrc
	 * for each of them.
	 */
	if (nubus_readdir(&dir, &ent) == -1) {
		/* We can't have this! */
		pr_err("Slot %X: Board resource not found!\n", slot);
		kfree(board);
		return;
	}

	if (ent.type < 1 || ent.type > 127)
		pr_warn("Slot %X: Board resource ID is invalid!\n", slot);

	board->procdir = nubus_proc_add_board(board);

	nubus_get_board_resource(board, slot, &ent);

	while (nubus_readdir(&dir, &ent) != -1) {
		struct nubus_rsrc *fres;

		fres = nubus_get_functional_resource(board, slot, &ent);
		if (fres == NULL)
			continue;

		/* Resources should appear in ascending ID order. This sanity
		 * check prevents duplicate resource IDs.
		 */
		if (fres->resid <= prev_resid) {
			kfree(fres);
			continue;
		}
		prev_resid = fres->resid;

		list_add_tail(&fres->list, &nubus_func_rsrcs);
	}

	if (nubus_device_register(board))
		put_device(&board->dev);
}