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#include <linux/numa_memblks.h>
16
17#include <asm/sections.h>
18
19static int cpu_to_node_map[NR_CPUS] = { [0 ... NR_CPUS-1] = NUMA_NO_NODE };
20
21bool numa_off;
22
23static __init int numa_parse_early_param(char *opt)
24{
25 if (!opt)
26 return -EINVAL;
27 if (str_has_prefix(str: opt, prefix: "off"))
28 numa_off = true;
29 if (!strncmp(opt, "fake=", 5))
30 return numa_emu_cmdline(str: opt + 5);
31
32 return 0;
33}
34early_param("numa", numa_parse_early_param);
35
36cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
37EXPORT_SYMBOL(node_to_cpumask_map);
38
39#ifdef CONFIG_DEBUG_PER_CPU_MAPS
40
41/*
42 * Returns a pointer to the bitmask of CPUs on Node 'node'.
43 */
44const struct cpumask *cpumask_of_node(int node)
45{
46
47 if (node == NUMA_NO_NODE)
48 return cpu_all_mask;
49
50 if (WARN_ON(node < 0 || node >= nr_node_ids))
51 return cpu_none_mask;
52
53 if (WARN_ON(node_to_cpumask_map[node] == NULL))
54 return cpu_online_mask;
55
56 return node_to_cpumask_map[node];
57}
58EXPORT_SYMBOL(cpumask_of_node);
59
60#endif
61
62#ifndef CONFIG_NUMA_EMU
63static void numa_update_cpu(unsigned int cpu, bool remove)
64{
65 int nid = cpu_to_node(cpu);
66
67 if (nid == NUMA_NO_NODE)
68 return;
69
70 if (remove)
71 cpumask_clear_cpu(cpu, node_to_cpumask_map[nid]);
72 else
73 cpumask_set_cpu(cpu, node_to_cpumask_map[nid]);
74}
75
76void numa_add_cpu(unsigned int cpu)
77{
78 numa_update_cpu(cpu, false);
79}
80
81void numa_remove_cpu(unsigned int cpu)
82{
83 numa_update_cpu(cpu, true);
84}
85#endif
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
147int 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 * Initialize NODE_DATA for a node on the local memory
194 */
195static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
196{
197 if (start_pfn >= end_pfn)
198 pr_info("Initmem setup node %d [<memory-less node>]\n", nid);
199
200 alloc_node_data(nid);
201
202 NODE_DATA(nid)->node_id = nid;
203 NODE_DATA(nid)->node_start_pfn = start_pfn;
204 NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
205}
206
207static int __init numa_register_nodes(void)
208{
209 int nid;
210
211 /* Check the validity of the memblock/node mapping */
212 if (!memblock_validate_numa_coverage(threshold_bytes: 0))
213 return -EINVAL;
214
215 /* Finally register nodes. */
216 for_each_node_mask(nid, numa_nodes_parsed) {
217 unsigned long start_pfn, end_pfn;
218
219 get_pfn_range_for_nid(nid, start_pfn: &start_pfn, end_pfn: &end_pfn);
220 setup_node_data(nid, start_pfn, end_pfn);
221 node_set_online(nid);
222 }
223
224 /* Setup online nodes to actual nodes*/
225 node_possible_map = numa_nodes_parsed;
226
227 return 0;
228}
229
230static int __init numa_init(int (*init_func)(void))
231{
232 int ret;
233
234 nodes_clear(numa_nodes_parsed);
235 nodes_clear(node_possible_map);
236 nodes_clear(node_online_map);
237
238 ret = numa_memblks_init(init_func, /* memblock_force_top_down */ false);
239 if (ret < 0)
240 goto out_free_distance;
241
242 if (nodes_empty(numa_nodes_parsed)) {
243 pr_info("No NUMA configuration found\n");
244 ret = -EINVAL;
245 goto out_free_distance;
246 }
247
248 ret = numa_register_nodes();
249 if (ret < 0)
250 goto out_free_distance;
251
252 setup_node_to_cpumask_map();
253
254 return 0;
255out_free_distance:
256 numa_reset_distance();
257 return ret;
258}
259
260/**
261 * dummy_numa_init() - Fallback dummy NUMA init
262 *
263 * Used if there's no underlying NUMA architecture, NUMA initialization
264 * fails, or NUMA is disabled on the command line.
265 *
266 * Must online at least one node (node 0) and add memory blocks that cover all
267 * allowed memory. It is unlikely that this function fails.
268 *
269 * Return: 0 on success, -errno on failure.
270 */
271static int __init dummy_numa_init(void)
272{
273 phys_addr_t start = memblock_start_of_DRAM();
274 phys_addr_t end = memblock_end_of_DRAM() - 1;
275 int ret;
276
277 if (numa_off)
278 pr_info("NUMA disabled\n"); /* Forced off on command line. */
279 pr_info("Faking a node at [mem %pap-%pap]\n", &start, &end);
280
281 ret = numa_add_memblk(nodeid: 0, start, end: end + 1);
282 if (ret) {
283 pr_err("NUMA init failed\n");
284 return ret;
285 }
286 node_set(0, numa_nodes_parsed);
287
288 numa_off = true;
289 return 0;
290}
291
292#ifdef CONFIG_ACPI_NUMA
293static int __init arch_acpi_numa_init(void)
294{
295 int ret;
296
297 ret = acpi_numa_init();
298 if (ret) {
299 pr_debug("Failed to initialise from firmware\n");
300 return ret;
301 }
302
303 return srat_disabled() ? -EINVAL : 0;
304}
305#else
306static int __init arch_acpi_numa_init(void)
307{
308 return -EOPNOTSUPP;
309}
310#endif
311
312/**
313 * arch_numa_init() - Initialize NUMA
314 *
315 * Try each configured NUMA initialization method until one succeeds. The
316 * last fallback is dummy single node config encompassing whole memory.
317 */
318void __init arch_numa_init(void)
319{
320 if (!numa_off) {
321 if (!acpi_disabled && !numa_init(init_func: arch_acpi_numa_init))
322 return;
323 if (acpi_disabled && !numa_init(init_func: of_numa_init))
324 return;
325 }
326
327 numa_init(init_func: dummy_numa_init);
328}
329
330#ifdef CONFIG_NUMA_EMU
331void __init numa_emu_update_cpu_to_node(int *emu_nid_to_phys,
332 unsigned int nr_emu_nids)
333{
334 int i, j;
335
336 /*
337 * Transform cpu_to_node_map table to use emulated nids by
338 * reverse-mapping phys_nid. The maps should always exist but fall
339 * back to zero just in case.
340 */
341 for (i = 0; i < ARRAY_SIZE(cpu_to_node_map); i++) {
342 if (cpu_to_node_map[i] == NUMA_NO_NODE)
343 continue;
344 for (j = 0; j < nr_emu_nids; j++)
345 if (cpu_to_node_map[i] == emu_nid_to_phys[j])
346 break;
347 cpu_to_node_map[i] = j < nr_emu_nids ? j : 0;
348 }
349}
350
351u64 __init numa_emu_dma_end(void)
352{
353 return memblock_start_of_DRAM() + SZ_4G;
354}
355
356void debug_cpumask_set_cpu(unsigned int cpu, int node, bool enable)
357{
358 struct cpumask *mask;
359
360 if (node == NUMA_NO_NODE)
361 return;
362
363 mask = node_to_cpumask_map[node];
364 if (!cpumask_available(mask)) {
365 pr_err("node_to_cpumask_map[%i] NULL\n", node);
366 dump_stack();
367 return;
368 }
369
370 if (enable)
371 cpumask_set_cpu(cpu, dstp: mask);
372 else
373 cpumask_clear_cpu(cpu, dstp: mask);
374
375 pr_debug("%s cpu %d node %d: mask now %*pbl\n",
376 enable ? "numa_add_cpu" : "numa_remove_cpu",
377 cpu, node, cpumask_pr_args(mask));
378}
379#endif /* CONFIG_NUMA_EMU */
380

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