1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * NUMA support, based on the x86 implementation.
4 *
5 * Copyright (C) 2015 Cavium Inc.
6 * Author: Ganapatrao Kulkarni <gkulkarni@cavium.com>
7 */
8
9#define pr_fmt(fmt) "NUMA: " fmt
10
11#include <linux/acpi.h>
12#include <linux/memblock.h>
13#include <linux/module.h>
14#include <linux/of.h>
15
16#include <asm/sections.h>
17
18struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
19EXPORT_SYMBOL(node_data);
20nodemask_t numa_nodes_parsed __initdata;
21static int cpu_to_node_map[NR_CPUS] = { [0 ... NR_CPUS-1] = NUMA_NO_NODE };
22
23static int numa_distance_cnt;
24static u8 *numa_distance;
25bool numa_off;
26
27static __init int numa_parse_early_param(char *opt)
28{
29 if (!opt)
30 return -EINVAL;
31 if (str_has_prefix(str: opt, prefix: "off"))
32 numa_off = true;
33
34 return 0;
35}
36early_param("numa", numa_parse_early_param);
37
38cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
39EXPORT_SYMBOL(node_to_cpumask_map);
40
41#ifdef CONFIG_DEBUG_PER_CPU_MAPS
42
43/*
44 * Returns a pointer to the bitmask of CPUs on Node 'node'.
45 */
46const struct cpumask *cpumask_of_node(int node)
47{
48
49 if (node == NUMA_NO_NODE)
50 return cpu_all_mask;
51
52 if (WARN_ON(node < 0 || node >= nr_node_ids))
53 return cpu_none_mask;
54
55 if (WARN_ON(node_to_cpumask_map[node] == NULL))
56 return cpu_online_mask;
57
58 return node_to_cpumask_map[node];
59}
60EXPORT_SYMBOL(cpumask_of_node);
61
62#endif
63
64static void numa_update_cpu(unsigned int cpu, bool remove)
65{
66 int nid = cpu_to_node(cpu);
67
68 if (nid == NUMA_NO_NODE)
69 return;
70
71 if (remove)
72 cpumask_clear_cpu(cpu, dstp: node_to_cpumask_map[nid]);
73 else
74 cpumask_set_cpu(cpu, dstp: node_to_cpumask_map[nid]);
75}
76
77void numa_add_cpu(unsigned int cpu)
78{
79 numa_update_cpu(cpu, remove: false);
80}
81
82void numa_remove_cpu(unsigned int cpu)
83{
84 numa_update_cpu(cpu, remove: true);
85}
86
87void numa_clear_node(unsigned int cpu)
88{
89 numa_remove_cpu(cpu);
90 set_cpu_numa_node(cpu, NUMA_NO_NODE);
91}
92
93/*
94 * Allocate node_to_cpumask_map based on number of available nodes
95 * Requires node_possible_map to be valid.
96 *
97 * Note: cpumask_of_node() is not valid until after this is done.
98 * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
99 */
100static void __init setup_node_to_cpumask_map(void)
101{
102 int node;
103
104 /* setup nr_node_ids if not done yet */
105 if (nr_node_ids == MAX_NUMNODES)
106 setup_nr_node_ids();
107
108 /* allocate and clear the mapping */
109 for (node = 0; node < nr_node_ids; node++) {
110 alloc_bootmem_cpumask_var(mask: &node_to_cpumask_map[node]);
111 cpumask_clear(dstp: node_to_cpumask_map[node]);
112 }
113
114 /* cpumask_of_node() will now work */
115 pr_debug("Node to cpumask map for %u nodes\n", nr_node_ids);
116}
117
118/*
119 * Set the cpu to node and mem mapping
120 */
121void numa_store_cpu_info(unsigned int cpu)
122{
123 set_cpu_numa_node(cpu, node: cpu_to_node_map[cpu]);
124}
125
126void __init early_map_cpu_to_node(unsigned int cpu, int nid)
127{
128 /* fallback to node 0 */
129 if (nid < 0 || nid >= MAX_NUMNODES || numa_off)
130 nid = 0;
131
132 cpu_to_node_map[cpu] = nid;
133
134 /*
135 * We should set the numa node of cpu0 as soon as possible, because it
136 * has already been set up online before. cpu_to_node(0) will soon be
137 * called.
138 */
139 if (!cpu)
140 set_cpu_numa_node(cpu, node: nid);
141}
142
143#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
144unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
145EXPORT_SYMBOL(__per_cpu_offset);
146
147static int __init early_cpu_to_node(int cpu)
148{
149 return cpu_to_node_map[cpu];
150}
151
152static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
153{
154 return node_distance(early_cpu_to_node(from), early_cpu_to_node(to));
155}
156
157void __init setup_per_cpu_areas(void)
158{
159 unsigned long delta;
160 unsigned int cpu;
161 int rc = -EINVAL;
162
163 if (pcpu_chosen_fc != PCPU_FC_PAGE) {
164 /*
165 * Always reserve area for module percpu variables. That's
166 * what the legacy allocator did.
167 */
168 rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
169 PERCPU_DYNAMIC_RESERVE, PAGE_SIZE,
170 cpu_distance_fn: pcpu_cpu_distance,
171 cpu_to_nd_fn: early_cpu_to_node);
172#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
173 if (rc < 0)
174 pr_warn("PERCPU: %s allocator failed (%d), falling back to page size\n",
175 pcpu_fc_names[pcpu_chosen_fc], rc);
176#endif
177 }
178
179#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
180 if (rc < 0)
181 rc = pcpu_page_first_chunk(PERCPU_MODULE_RESERVE, cpu_to_nd_fn: early_cpu_to_node);
182#endif
183 if (rc < 0)
184 panic(fmt: "Failed to initialize percpu areas (err=%d).", rc);
185
186 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
187 for_each_possible_cpu(cpu)
188 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
189}
190#endif
191
192/**
193 * numa_add_memblk() - Set node id to memblk
194 * @nid: NUMA node ID of the new memblk
195 * @start: Start address of the new memblk
196 * @end: End address of the new memblk
197 *
198 * RETURNS:
199 * 0 on success, -errno on failure.
200 */
201int __init numa_add_memblk(int nid, u64 start, u64 end)
202{
203 int ret;
204
205 ret = memblock_set_node(base: start, size: (end - start), type: &memblock.memory, nid);
206 if (ret < 0) {
207 pr_err("memblock [0x%llx - 0x%llx] failed to add on node %d\n",
208 start, (end - 1), nid);
209 return ret;
210 }
211
212 node_set(nid, numa_nodes_parsed);
213 return ret;
214}
215
216/*
217 * Initialize NODE_DATA for a node on the local memory
218 */
219static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
220{
221 const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES);
222 u64 nd_pa;
223 void *nd;
224 int tnid;
225
226 if (start_pfn >= end_pfn)
227 pr_info("Initmem setup node %d [<memory-less node>]\n", nid);
228
229 nd_pa = memblock_phys_alloc_try_nid(size: nd_size, SMP_CACHE_BYTES, nid);
230 if (!nd_pa)
231 panic(fmt: "Cannot allocate %zu bytes for node %d data\n",
232 nd_size, nid);
233
234 nd = __va(nd_pa);
235
236 /* report and initialize */
237 pr_info("NODE_DATA [mem %#010Lx-%#010Lx]\n",
238 nd_pa, nd_pa + nd_size - 1);
239 tnid = early_pfn_to_nid(pfn: nd_pa >> PAGE_SHIFT);
240 if (tnid != nid)
241 pr_info("NODE_DATA(%d) on node %d\n", nid, tnid);
242
243 node_data[nid] = nd;
244 memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
245 NODE_DATA(nid)->node_id = nid;
246 NODE_DATA(nid)->node_start_pfn = start_pfn;
247 NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
248}
249
250/*
251 * numa_free_distance
252 *
253 * The current table is freed.
254 */
255void __init numa_free_distance(void)
256{
257 size_t size;
258
259 if (!numa_distance)
260 return;
261
262 size = numa_distance_cnt * numa_distance_cnt *
263 sizeof(numa_distance[0]);
264
265 memblock_free(ptr: numa_distance, size);
266 numa_distance_cnt = 0;
267 numa_distance = NULL;
268}
269
270/*
271 * Create a new NUMA distance table.
272 */
273static int __init numa_alloc_distance(void)
274{
275 size_t size;
276 int i, j;
277
278 size = nr_node_ids * nr_node_ids * sizeof(numa_distance[0]);
279 numa_distance = memblock_alloc(size, PAGE_SIZE);
280 if (WARN_ON(!numa_distance))
281 return -ENOMEM;
282
283 numa_distance_cnt = nr_node_ids;
284
285 /* fill with the default distances */
286 for (i = 0; i < numa_distance_cnt; i++)
287 for (j = 0; j < numa_distance_cnt; j++)
288 numa_distance[i * numa_distance_cnt + j] = i == j ?
289 LOCAL_DISTANCE : REMOTE_DISTANCE;
290
291 pr_debug("Initialized distance table, cnt=%d\n", numa_distance_cnt);
292
293 return 0;
294}
295
296/**
297 * numa_set_distance() - Set inter node NUMA distance from node to node.
298 * @from: the 'from' node to set distance
299 * @to: the 'to' node to set distance
300 * @distance: NUMA distance
301 *
302 * Set the distance from node @from to @to to @distance.
303 * If distance table doesn't exist, a warning is printed.
304 *
305 * If @from or @to is higher than the highest known node or lower than zero
306 * or @distance doesn't make sense, the call is ignored.
307 */
308void __init numa_set_distance(int from, int to, int distance)
309{
310 if (!numa_distance) {
311 pr_warn_once("Warning: distance table not allocated yet\n");
312 return;
313 }
314
315 if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
316 from < 0 || to < 0) {
317 pr_warn_once("Warning: node ids are out of bound, from=%d to=%d distance=%d\n",
318 from, to, distance);
319 return;
320 }
321
322 if ((u8)distance != distance ||
323 (from == to && distance != LOCAL_DISTANCE)) {
324 pr_warn_once("Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
325 from, to, distance);
326 return;
327 }
328
329 numa_distance[from * numa_distance_cnt + to] = distance;
330}
331
332/*
333 * Return NUMA distance @from to @to
334 */
335int __node_distance(int from, int to)
336{
337 if (from >= numa_distance_cnt || to >= numa_distance_cnt)
338 return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
339 return numa_distance[from * numa_distance_cnt + to];
340}
341EXPORT_SYMBOL(__node_distance);
342
343static int __init numa_register_nodes(void)
344{
345 int nid;
346 struct memblock_region *mblk;
347
348 /* Check that valid nid is set to memblks */
349 for_each_mem_region(mblk) {
350 int mblk_nid = memblock_get_region_node(r: mblk);
351 phys_addr_t start = mblk->base;
352 phys_addr_t end = mblk->base + mblk->size - 1;
353
354 if (mblk_nid == NUMA_NO_NODE || mblk_nid >= MAX_NUMNODES) {
355 pr_warn("Warning: invalid memblk node %d [mem %pap-%pap]\n",
356 mblk_nid, &start, &end);
357 return -EINVAL;
358 }
359 }
360
361 /* Finally register nodes. */
362 for_each_node_mask(nid, numa_nodes_parsed) {
363 unsigned long start_pfn, end_pfn;
364
365 get_pfn_range_for_nid(nid, start_pfn: &start_pfn, end_pfn: &end_pfn);
366 setup_node_data(nid, start_pfn, end_pfn);
367 node_set_online(nid);
368 }
369
370 /* Setup online nodes to actual nodes*/
371 node_possible_map = numa_nodes_parsed;
372
373 return 0;
374}
375
376static int __init numa_init(int (*init_func)(void))
377{
378 int ret;
379
380 nodes_clear(numa_nodes_parsed);
381 nodes_clear(node_possible_map);
382 nodes_clear(node_online_map);
383
384 ret = numa_alloc_distance();
385 if (ret < 0)
386 return ret;
387
388 ret = init_func();
389 if (ret < 0)
390 goto out_free_distance;
391
392 if (nodes_empty(numa_nodes_parsed)) {
393 pr_info("No NUMA configuration found\n");
394 ret = -EINVAL;
395 goto out_free_distance;
396 }
397
398 ret = numa_register_nodes();
399 if (ret < 0)
400 goto out_free_distance;
401
402 setup_node_to_cpumask_map();
403
404 return 0;
405out_free_distance:
406 numa_free_distance();
407 return ret;
408}
409
410/**
411 * dummy_numa_init() - Fallback dummy NUMA init
412 *
413 * Used if there's no underlying NUMA architecture, NUMA initialization
414 * fails, or NUMA is disabled on the command line.
415 *
416 * Must online at least one node (node 0) and add memory blocks that cover all
417 * allowed memory. It is unlikely that this function fails.
418 *
419 * Return: 0 on success, -errno on failure.
420 */
421static int __init dummy_numa_init(void)
422{
423 phys_addr_t start = memblock_start_of_DRAM();
424 phys_addr_t end = memblock_end_of_DRAM() - 1;
425 int ret;
426
427 if (numa_off)
428 pr_info("NUMA disabled\n"); /* Forced off on command line. */
429 pr_info("Faking a node at [mem %pap-%pap]\n", &start, &end);
430
431 ret = numa_add_memblk(nid: 0, start, end: end + 1);
432 if (ret) {
433 pr_err("NUMA init failed\n");
434 return ret;
435 }
436
437 numa_off = true;
438 return 0;
439}
440
441#ifdef CONFIG_ACPI_NUMA
442static int __init arch_acpi_numa_init(void)
443{
444 int ret;
445
446 ret = acpi_numa_init();
447 if (ret) {
448 pr_info("Failed to initialise from firmware\n");
449 return ret;
450 }
451
452 return srat_disabled() ? -EINVAL : 0;
453}
454#else
455static int __init arch_acpi_numa_init(void)
456{
457 return -EOPNOTSUPP;
458}
459#endif
460
461/**
462 * arch_numa_init() - Initialize NUMA
463 *
464 * Try each configured NUMA initialization method until one succeeds. The
465 * last fallback is dummy single node config encompassing whole memory.
466 */
467void __init arch_numa_init(void)
468{
469 if (!numa_off) {
470 if (!acpi_disabled && !numa_init(init_func: arch_acpi_numa_init))
471 return;
472 if (acpi_disabled && !numa_init(init_func: of_numa_init))
473 return;
474 }
475
476 numa_init(init_func: dummy_numa_init);
477}
478

source code of linux/drivers/base/arch_numa.c