+ * Sets up nr_nodes fake nodes interleaved over physical nodes ranging from addr
+ * to max_addr. The return value is the number of nodes allocated.
+ */
+static int __init split_nodes_interleave(u64 addr, u64 max_addr,
+ int nr_phys_nodes, int nr_nodes)
+{
+ nodemask_t physnode_mask = NODE_MASK_NONE;
+ u64 size;
+ int big;
+ int ret = 0;
+ int i;
+
+ if (nr_nodes <= 0)
+ return -1;
+ if (nr_nodes > MAX_NUMNODES) {
+ pr_info("numa=fake=%d too large, reducing to %d\n",
+ nr_nodes, MAX_NUMNODES);
+ nr_nodes = MAX_NUMNODES;
+ }
+
+ size = (max_addr - addr - e820_hole_size(addr, max_addr)) / nr_nodes;
+ /*
+ * Calculate the number of big nodes that can be allocated as a result
+ * of consolidating the remainder.
+ */
+ big = ((size & ~FAKE_NODE_MIN_HASH_MASK) & nr_nodes) /
+ FAKE_NODE_MIN_SIZE;
+
+ size &= FAKE_NODE_MIN_HASH_MASK;
+ if (!size) {
+ pr_err("Not enough memory for each node. "
+ "NUMA emulation disabled.\n");
+ return -1;
+ }
+
+ for (i = 0; i < nr_phys_nodes; i++)
+ if (physnodes[i].start != physnodes[i].end)
+ node_set(i, physnode_mask);
+
+ /*
+ * Continue to fill physical nodes with fake nodes until there is no
+ * memory left on any of them.
+ */
+ while (nodes_weight(physnode_mask)) {
+ for_each_node_mask(i, physnode_mask) {
+ u64 end = physnodes[i].start + size;
+ u64 dma32_end = PFN_PHYS(MAX_DMA32_PFN);
+
+ if (ret < big)
+ end += FAKE_NODE_MIN_SIZE;
+
+ /*
+ * Continue to add memory to this fake node if its
+ * non-reserved memory is less than the per-node size.
+ */
+ while (end - physnodes[i].start -
+ e820_hole_size(physnodes[i].start, end) < size) {
+ end += FAKE_NODE_MIN_SIZE;
+ if (end > physnodes[i].end) {
+ end = physnodes[i].end;
+ break;
+ }
+ }
+
+ /*
+ * If there won't be at least FAKE_NODE_MIN_SIZE of
+ * non-reserved memory in ZONE_DMA32 for the next node,
+ * this one must extend to the boundary.
+ */
+ if (end < dma32_end && dma32_end - end -
+ e820_hole_size(end, dma32_end) < FAKE_NODE_MIN_SIZE)
+ end = dma32_end;
+
+ /*
+ * If there won't be enough non-reserved memory for the
+ * next node, this one must extend to the end of the
+ * physical node.
+ */
+ if (physnodes[i].end - end -
+ e820_hole_size(end, physnodes[i].end) < size)
+ end = physnodes[i].end;
+
+ /*
+ * Avoid allocating more nodes than requested, which can
+ * happen as a result of rounding down each node's size
+ * to FAKE_NODE_MIN_SIZE.
+ */
+ if (nodes_weight(physnode_mask) + ret >= nr_nodes)
+ end = physnodes[i].end;
+
+ if (setup_node_range(ret++, &physnodes[i].start,
+ end - physnodes[i].start,
+ physnodes[i].end) < 0)
+ node_clear(i, physnode_mask);
+ }
+ }
+ return ret;
+}
+
+/*