- int i;
- struct bootnode nodes[MAX_NUMNODES];
- unsigned long sz = ((end_pfn - start_pfn)<<PAGE_SHIFT) / numa_fake;
-
- /* Kludge needed for the hash function */
- if (hweight64(sz) > 1) {
- unsigned long x = 1;
- while ((x << 1) < sz)
- x <<= 1;
- if (x < sz/2)
- printk(KERN_ERR "Numa emulation unbalanced. Complain to maintainer\n");
- sz = x;
- }
-
- memset(&nodes,0,sizeof(nodes));
- for (i = 0; i < numa_fake; i++) {
- nodes[i].start = (start_pfn<<PAGE_SHIFT) + i*sz;
- if (i == numa_fake-1)
- sz = (end_pfn<<PAGE_SHIFT) - nodes[i].start;
- nodes[i].end = nodes[i].start + sz;
- printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n",
- i,
- nodes[i].start, nodes[i].end,
- (nodes[i].end - nodes[i].start) >> 20);
- node_set_online(i);
- }
- memnode_shift = compute_hash_shift(nodes, numa_fake);
- if (memnode_shift < 0) {
- memnode_shift = 0;
- printk(KERN_ERR "No NUMA hash function found. Emulation disabled.\n");
- return -1;
- }
- for_each_online_node(i)
+ int ret = 0;
+ nodes[nid].start = *addr;
+ *addr += size;
+ if (*addr >= max_addr) {
+ *addr = max_addr;
+ ret = -1;
+ }
+ nodes[nid].end = *addr;
+ node_set_online(nid);
+ printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n", nid,
+ nodes[nid].start, nodes[nid].end,
+ (nodes[nid].end - nodes[nid].start) >> 20);
+ return ret;
+}
+
+/*
+ * Splits num_nodes nodes up equally starting at node_start. The return value
+ * is the number of nodes split up and addr is adjusted to be at the end of the
+ * last node allocated.
+ */
+static int __init split_nodes_equally(struct bootnode *nodes, u64 *addr,
+ u64 max_addr, int node_start,
+ int num_nodes)
+{
+ unsigned int big;
+ u64 size;
+ int i;
+
+ if (num_nodes <= 0)
+ return -1;
+ if (num_nodes > MAX_NUMNODES)
+ num_nodes = MAX_NUMNODES;
+ size = (max_addr - *addr - E820_ADDR_HOLE_SIZE(*addr, max_addr)) /
+ num_nodes;
+ /*
+ * Calculate the number of big nodes that can be allocated as a result
+ * of consolidating the leftovers.
+ */
+ big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * num_nodes) /
+ FAKE_NODE_MIN_SIZE;
+
+ /* Round down to nearest FAKE_NODE_MIN_SIZE. */
+ size &= FAKE_NODE_MIN_HASH_MASK;
+ if (!size) {
+ printk(KERN_ERR "Not enough memory for each node. "
+ "NUMA emulation disabled.\n");
+ return -1;
+ }
+
+ for (i = node_start; i < num_nodes + node_start; i++) {
+ u64 end = *addr + size;
+ if (i < big)
+ end += FAKE_NODE_MIN_SIZE;
+ /*
+ * The final node can have the remaining system RAM. Other
+ * nodes receive roughly the same amount of available pages.
+ */
+ if (i == num_nodes + node_start - 1)
+ end = max_addr;
+ else
+ while (end - *addr - E820_ADDR_HOLE_SIZE(*addr, end) <
+ size) {
+ end += FAKE_NODE_MIN_SIZE;
+ if (end > max_addr) {
+ end = max_addr;
+ break;
+ }
+ }
+ if (setup_node_range(i, nodes, addr, end - *addr, max_addr) < 0)
+ break;
+ }
+ return i - node_start + 1;
+}
+
+/*
+ * Sets up the system RAM area from start_pfn to end_pfn according to the
+ * numa=fake command-line option.
+ */
+static int __init numa_emulation(unsigned long start_pfn, unsigned long end_pfn)
+{
+ struct bootnode nodes[MAX_NUMNODES];
+ u64 addr = start_pfn << PAGE_SHIFT;
+ u64 max_addr = end_pfn << PAGE_SHIFT;
+ unsigned int coeff;
+ unsigned int num = 0;
+ int num_nodes = 0;
+ u64 size;
+ int i;
+
+ memset(&nodes, 0, sizeof(nodes));
+ /*
+ * If the numa=fake command-line is just a single number N, split the
+ * system RAM into N fake nodes.
+ */
+ if (!strchr(cmdline, '*') && !strchr(cmdline, ',')) {
+ num_nodes = split_nodes_equally(nodes, &addr, max_addr, 0,
+ simple_strtol(cmdline, NULL, 0));
+ if (num_nodes < 0)
+ return num_nodes;
+ goto out;
+ }
+
+ /* Parse the command line. */
+ for (coeff = 1; ; cmdline++) {
+ if (*cmdline && isdigit(*cmdline)) {
+ num = num * 10 + *cmdline - '0';
+ continue;
+ }
+ if (*cmdline == '*')
+ coeff = num;
+ if (!*cmdline || *cmdline == ',') {
+ /*
+ * Round down to the nearest FAKE_NODE_MIN_SIZE.
+ * Command-line coefficients are in megabytes.
+ */
+ size = ((u64)num << 20) & FAKE_NODE_MIN_HASH_MASK;
+ if (size) {
+ for (i = 0; i < coeff; i++, num_nodes++)
+ if (setup_node_range(num_nodes, nodes,
+ &addr, size, max_addr) < 0)
+ goto done;
+ coeff = 1;
+ }
+ }
+ if (!*cmdline)
+ break;
+ num = 0;
+ }
+done:
+ if (!num_nodes)
+ return -1;
+ /* Fill remainder of system RAM with a final node, if appropriate. */
+ if (addr < max_addr) {
+ setup_node_range(num_nodes, nodes, &addr, max_addr - addr,
+ max_addr);
+ num_nodes++;
+ }
+out:
+ memnode_shift = compute_hash_shift(nodes, num_nodes);
+ if (memnode_shift < 0) {
+ memnode_shift = 0;
+ printk(KERN_ERR "No NUMA hash function found. NUMA emulation "
+ "disabled.\n");
+ return -1;
+ }
+
+ /*
+ * We need to vacate all active ranges that may have been registered by
+ * SRAT.
+ */
+ remove_all_active_ranges();
+ for_each_online_node(i) {
+ e820_register_active_regions(i, nodes[i].start >> PAGE_SHIFT,
+ nodes[i].end >> PAGE_SHIFT);