2 * ACPI 3.0 based NUMA setup
3 * Copyright 2004 Andi Kleen, SuSE Labs.
5 * Reads the ACPI SRAT table to figure out what memory belongs to which CPUs.
7 * Called from acpi_numa_init while reading the SRAT and SLIT tables.
8 * Assumes all memory regions belonging to a single proximity domain
9 * are in one chunk. Holes between them will be included in the node.
12 #include <linux/kernel.h>
13 #include <linux/acpi.h>
14 #include <linux/mmzone.h>
15 #include <linux/bitmap.h>
16 #include <linux/module.h>
17 #include <linux/topology.h>
18 #include <linux/bootmem.h>
20 #include <asm/proto.h>
24 int acpi_numa __initdata;
26 #if (defined(CONFIG_ACPI_HOTPLUG_MEMORY) || \
27 defined(CONFIG_ACPI_HOTPLUG_MEMORY_MODULE)) \
28 && !defined(CONFIG_MEMORY_HOTPLUG)
29 #define RESERVE_HOTADD 1
32 static struct acpi_table_slit *acpi_slit;
34 static nodemask_t nodes_parsed __initdata;
35 static struct bootnode nodes[MAX_NUMNODES] __initdata;
36 static struct bootnode nodes_add[MAX_NUMNODES] __initdata;
37 static int found_add_area __initdata;
38 int hotadd_percent __initdata = 0;
39 #ifndef RESERVE_HOTADD
40 #define hotadd_percent 0 /* Ignore all settings */
43 /* Too small nodes confuse the VM badly. Usually they result
45 #define NODE_MIN_SIZE (4*1024*1024)
47 static __init int setup_node(int pxm)
49 return acpi_map_pxm_to_node(pxm);
52 static __init int conflicting_nodes(unsigned long start, unsigned long end)
55 for_each_node_mask(i, nodes_parsed) {
56 struct bootnode *nd = &nodes[i];
57 if (nd->start == nd->end)
59 if (nd->end > start && nd->start < end)
61 if (nd->end == end && nd->start == start)
67 static __init void cutoff_node(int i, unsigned long start, unsigned long end)
69 struct bootnode *nd = &nodes[i];
74 if (nd->start < start) {
76 if (nd->end < nd->start)
81 if (nd->start > nd->end)
86 static __init void bad_srat(void)
89 printk(KERN_ERR "SRAT: SRAT not used.\n");
92 for (i = 0; i < MAX_LOCAL_APIC; i++)
93 apicid_to_node[i] = NUMA_NO_NODE;
94 for (i = 0; i < MAX_NUMNODES; i++)
95 nodes_add[i].start = nodes[i].end = 0;
96 remove_all_active_ranges();
99 static __init inline int srat_disabled(void)
101 return numa_off || acpi_numa < 0;
105 * A lot of BIOS fill in 10 (= no distance) everywhere. This messes
106 * up the NUMA heuristics which wants the local node to have a smaller
107 * distance than the others.
108 * Do some quick checks here and only use the SLIT if it passes.
110 static __init int slit_valid(struct acpi_table_slit *slit)
113 int d = slit->localities;
114 for (i = 0; i < d; i++) {
115 for (j = 0; j < d; j++) {
116 u8 val = slit->entry[d*i + j];
120 } else if (val <= 10)
127 /* Callback for SLIT parsing */
128 void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
130 if (!slit_valid(slit)) {
131 printk(KERN_INFO "ACPI: SLIT table looks invalid. Not used.\n");
137 /* Callback for Proximity Domain -> LAPIC mapping */
139 acpi_numa_processor_affinity_init(struct acpi_table_processor_affinity *pa)
144 if (pa->header.length != sizeof(struct acpi_table_processor_affinity)) {
148 if (pa->flags.enabled == 0)
150 pxm = pa->proximity_domain;
151 node = setup_node(pxm);
153 printk(KERN_ERR "SRAT: Too many proximity domains %x\n", pxm);
157 apicid_to_node[pa->apic_id] = node;
159 printk(KERN_INFO "SRAT: PXM %u -> APIC %u -> Node %u\n",
160 pxm, pa->apic_id, node);
163 #ifdef RESERVE_HOTADD
165 * Protect against too large hotadd areas that would fill up memory.
167 static int hotadd_enough_memory(struct bootnode *nd)
169 static unsigned long allocated;
170 static unsigned long last_area_end;
171 unsigned long pages = (nd->end - nd->start) >> PAGE_SHIFT;
172 long mem = pages * sizeof(struct page);
174 unsigned long allowed;
175 unsigned long oldpages = pages;
179 allowed = (end_pfn - absent_pages_in_range(0, end_pfn)) * PAGE_SIZE;
180 allowed = (allowed / 100) * hotadd_percent;
181 if (allocated + mem > allowed) {
183 /* Give them at least part of their hotadd memory upto hotadd_percent
184 It would be better to spread the limit out
185 over multiple hotplug areas, but that is too complicated
187 if (allocated >= allowed)
189 range = allowed - allocated;
190 pages = (range / PAGE_SIZE);
191 mem = pages * sizeof(struct page);
192 nd->end = nd->start + range;
194 /* Not completely fool proof, but a good sanity check */
195 addr = find_e820_area(last_area_end, end_pfn<<PAGE_SHIFT, mem);
198 if (pages != oldpages)
199 printk(KERN_NOTICE "SRAT: Hotadd area limited to %lu bytes\n",
200 pages << PAGE_SHIFT);
201 last_area_end = addr + mem;
207 * It is fine to add this area to the nodes data it will be used later
208 * This code supports one contigious hot add area per node.
210 static int reserve_hotadd(int node, unsigned long start, unsigned long end)
212 unsigned long s_pfn = start >> PAGE_SHIFT;
213 unsigned long e_pfn = end >> PAGE_SHIFT;
215 struct bootnode *nd = &nodes_add[node];
217 /* I had some trouble with strange memory hotadd regions breaking
218 the boot. Be very strict here and reject anything unexpected.
219 If you want working memory hotadd write correct SRATs.
221 The node size check is a basic sanity check to guard against
223 if ((signed long)(end - start) < NODE_MIN_SIZE) {
224 printk(KERN_ERR "SRAT: Hotplug area too small\n");
228 /* This check might be a bit too strict, but I'm keeping it for now. */
229 if (absent_pages_in_range(s_pfn, e_pfn) != e_pfn - s_pfn) {
231 "SRAT: Hotplug area %lu -> %lu has existing memory\n",
236 if (!hotadd_enough_memory(&nodes_add[node])) {
237 printk(KERN_ERR "SRAT: Hotplug area too large\n");
244 if (nd->start == nd->end) {
249 if (nd->start == end) {
253 if (nd->end == start) {
258 printk(KERN_ERR "SRAT: Hotplug zone not continuous. Partly ignored\n");
261 if ((nd->end >> PAGE_SHIFT) > end_pfn)
262 end_pfn = nd->end >> PAGE_SHIFT;
265 printk(KERN_INFO "SRAT: hot plug zone found %Lx - %Lx\n", nd->start, nd->end);
270 /* Callback for parsing of the Proximity Domain <-> Memory Area mappings */
272 acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma)
274 struct bootnode *nd, oldnode;
275 unsigned long start, end;
281 if (ma->header.length != sizeof(struct acpi_table_memory_affinity)) {
285 if (ma->flags.enabled == 0)
287 if (ma->flags.hot_pluggable && hotadd_percent == 0)
289 start = ma->base_addr_lo | ((u64)ma->base_addr_hi << 32);
290 end = start + (ma->length_lo | ((u64)ma->length_hi << 32));
291 pxm = ma->proximity_domain;
292 node = setup_node(pxm);
294 printk(KERN_ERR "SRAT: Too many proximity domains.\n");
298 i = conflicting_nodes(start, end);
301 "SRAT: Warning: PXM %d (%lx-%lx) overlaps with itself (%Lx-%Lx)\n",
302 pxm, start, end, nodes[i].start, nodes[i].end);
305 "SRAT: PXM %d (%lx-%lx) overlaps with PXM %d (%Lx-%Lx)\n",
306 pxm, start, end, node_to_pxm(i),
307 nodes[i].start, nodes[i].end);
313 if (!node_test_and_set(node, nodes_parsed)) {
317 if (start < nd->start)
323 printk(KERN_INFO "SRAT: Node %u PXM %u %Lx-%Lx\n", node, pxm,
325 e820_register_active_regions(node, nd->start >> PAGE_SHIFT,
326 nd->end >> PAGE_SHIFT);
327 push_node_boundaries(node, nd->start >> PAGE_SHIFT,
328 nd->end >> PAGE_SHIFT);
330 #ifdef RESERVE_HOTADD
331 if (ma->flags.hot_pluggable && reserve_hotadd(node, start, end) < 0) {
332 /* Ignore hotadd region. Undo damage */
333 printk(KERN_NOTICE "SRAT: Hotplug region ignored\n");
335 if ((nd->start | nd->end) == 0)
336 node_clear(node, nodes_parsed);
341 /* Sanity check to catch more bad SRATs (they are amazingly common).
342 Make sure the PXMs cover all memory. */
343 static int nodes_cover_memory(void)
346 unsigned long pxmram, e820ram;
349 for_each_node_mask(i, nodes_parsed) {
350 unsigned long s = nodes[i].start >> PAGE_SHIFT;
351 unsigned long e = nodes[i].end >> PAGE_SHIFT;
353 pxmram -= absent_pages_in_range(s, e);
354 pxmram -= nodes_add[i].end - nodes_add[i].start;
355 if ((long)pxmram < 0)
359 e820ram = end_pfn - absent_pages_in_range(0, end_pfn);
360 /* We seem to lose 3 pages somewhere. Allow a bit of slack. */
361 if ((long)(e820ram - pxmram) >= 1*1024*1024) {
363 "SRAT: PXMs only cover %luMB of your %luMB e820 RAM. Not used.\n",
364 (pxmram << PAGE_SHIFT) >> 20,
365 (e820ram << PAGE_SHIFT) >> 20);
371 static void unparse_node(int node)
374 node_clear(node, nodes_parsed);
375 for (i = 0; i < MAX_LOCAL_APIC; i++) {
376 if (apicid_to_node[i] == node)
377 apicid_to_node[i] = NUMA_NO_NODE;
381 void __init acpi_numa_arch_fixup(void) {}
383 /* Use the information discovered above to actually set up the nodes. */
384 int __init acpi_scan_nodes(unsigned long start, unsigned long end)
388 /* First clean up the node list */
389 for (i = 0; i < MAX_NUMNODES; i++) {
390 cutoff_node(i, start, end);
391 if ((nodes[i].end - nodes[i].start) < NODE_MIN_SIZE) {
400 if (!nodes_cover_memory()) {
405 memnode_shift = compute_hash_shift(nodes, MAX_NUMNODES);
406 if (memnode_shift < 0) {
408 "SRAT: No NUMA node hash function found. Contact maintainer\n");
413 /* Finally register nodes */
414 for_each_node_mask(i, nodes_parsed)
415 setup_node_bootmem(i, nodes[i].start, nodes[i].end);
416 /* Try again in case setup_node_bootmem missed one due
417 to missing bootmem */
418 for_each_node_mask(i, nodes_parsed)
420 setup_node_bootmem(i, nodes[i].start, nodes[i].end);
422 for (i = 0; i < NR_CPUS; i++) {
423 if (cpu_to_node[i] == NUMA_NO_NODE)
425 if (!node_isset(cpu_to_node[i], nodes_parsed))
426 numa_set_node(i, NUMA_NO_NODE);
432 void __init srat_reserve_add_area(int nodeid)
434 if (found_add_area && nodes_add[nodeid].end) {
437 printk(KERN_INFO "SRAT: Reserving hot-add memory space "
438 "for node %d at %Lx-%Lx\n",
439 nodeid, nodes_add[nodeid].start, nodes_add[nodeid].end);
440 total_mb = (nodes_add[nodeid].end - nodes_add[nodeid].start)
442 total_mb *= sizeof(struct page);
444 printk(KERN_INFO "SRAT: This will cost you %Lu MB of "
445 "pre-allocated memory.\n", (unsigned long long)total_mb);
446 reserve_bootmem_node(NODE_DATA(nodeid), nodes_add[nodeid].start,
447 nodes_add[nodeid].end - nodes_add[nodeid].start);
451 int __node_distance(int a, int b)
456 return a == b ? 10 : 20;
457 index = acpi_slit->localities * node_to_pxm(a);
458 return acpi_slit->entry[index + node_to_pxm(b)];
461 EXPORT_SYMBOL(__node_distance);