numa.c

early_param("numa", early_numa);

#ifdef CONFIG_MEMORY_HOTPLUG
/*
 * Validate the node associated with the memory section we are
 * trying to add.
 */
int valid_hot_add_scn(int *nid, unsigned long start, u32 lmb_size,
		      unsigned long scn_addr)
{
	nodemask_t nodes;

	if (*nid < 0 || !node_online(*nid))
		*nid = any_online_node(NODE_MASK_ALL);

	if ((scn_addr >= start) && (scn_addr < (start + lmb_size))) {
		nodes_setall(nodes);
		while (NODE_DATA(*nid)->node_spanned_pages == 0) {
			node_clear(*nid, nodes);
			*nid = any_online_node(nodes);
		}

		return 1;
	}

	return 0;
}

/*
 * Find the node associated with a hot added memory section represented
 * by the ibm,dynamic-reconfiguration-memory node.
 */
static int hot_add_drconf_scn_to_nid(struct device_node *memory,
				     unsigned long scn_addr)
{
	const u32 *dm;
	unsigned int n, rc;
	unsigned long lmb_size;
	int default_nid = any_online_node(NODE_MASK_ALL);
	int nid;
	struct assoc_arrays aa;

	n = of_get_drconf_memory(memory, &dm);
	if (!n)
		return default_nid;;

	lmb_size = of_get_lmb_size(memory);
	if (!lmb_size)
		return default_nid;

	rc = of_get_assoc_arrays(memory, &aa);
	if (rc)
		return default_nid;

	for (; n != 0; --n) {
		struct of_drconf_cell drmem;

		read_drconf_cell(&drmem, &dm);

		/* skip this block if it is reserved or not assigned to
		 * this partition */
		if ((drmem.flags & DRCONF_MEM_RESERVED)
		    || !(drmem.flags & DRCONF_MEM_ASSIGNED))
			continue;

		nid = of_drconf_to_nid_single(&drmem, &aa);

		if (valid_hot_add_scn(&nid, drmem.base_addr, lmb_size,
				      scn_addr))
			return nid;
	}

	BUG();	/* section address should be found above */
	return 0;
}

/*
 * Find the node associated with a hot added memory section.  Section
 * corresponds to a SPARSEMEM section, not an LMB.  It is assumed that
 * sections are fully contained within a single LMB.
 */
int hot_add_scn_to_nid(unsigned long scn_addr)
{
	struct device_node *memory = NULL;
	int nid;

	if (!numa_enabled || (min_common_depth < 0))
		return any_online_node(NODE_MASK_ALL);

	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
	if (memory) {
		nid = hot_add_drconf_scn_to_nid(memory, scn_addr);
		of_node_put(memory);
		return nid;
	}

	while ((memory = of_find_node_by_type(memory, "memory")) != NULL) {
		unsigned long start, size;
		int ranges;
		const unsigned int *memcell_buf;
		unsigned int len;

		memcell_buf = of_get_property(memory, "reg", &len);
		if (!memcell_buf || len <= 0)
			continue;

		/* ranges in cell */
		ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
ha_new_range:
		start = read_n_cells(n_mem_addr_cells, &memcell_buf);
		size = read_n_cells(n_mem_size_cells, &memcell_buf);
		nid = of_node_to_nid_single(memory);

		if (valid_hot_add_scn(&nid, start, size, scn_addr)) {
			of_node_put(memory);
			return nid;
		}

		if (--ranges)		/* process all ranges in cell */
			goto ha_new_range;
	}
	BUG();	/* section address should be found above */
	return 0;
}
#endif /* CONFIG_MEMORY_HOTPLUG */