1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/slab.h>
  3#include <linux/kernel.h>
  4#include <linux/bitops.h>
  5#include <linux/cpumask.h>
  6#include <linux/export.h>
  7#include <linux/memblock.h>
  8#include <linux/numa.h>
  9
 10/**
 11 * cpumask_next - get the next cpu in a cpumask
 12 * @n: the cpu prior to the place to search (ie. return will be > @n)
 13 * @srcp: the cpumask pointer
 14 *
 15 * Returns >= nr_cpu_ids if no further cpus set.
 16 */
 17unsigned int cpumask_next(int n, const struct cpumask *srcp)
 18{
 19	/* -1 is a legal arg here. */
 20	if (n != -1)
 21		cpumask_check(n);
 22	return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n + 1);
 23}
 24EXPORT_SYMBOL(cpumask_next);
 25
 26/**
 27 * cpumask_next_and - get the next cpu in *src1p & *src2p
 28 * @n: the cpu prior to the place to search (ie. return will be > @n)
 29 * @src1p: the first cpumask pointer
 30 * @src2p: the second cpumask pointer
 31 *
 32 * Returns >= nr_cpu_ids if no further cpus set in both.
 33 */
 34int cpumask_next_and(int n, const struct cpumask *src1p,
 35		     const struct cpumask *src2p)
 36{
 37	/* -1 is a legal arg here. */
 38	if (n != -1)
 39		cpumask_check(n);
 40	return find_next_and_bit(cpumask_bits(src1p), cpumask_bits(src2p),
 41		nr_cpumask_bits, n + 1);
 42}
 43EXPORT_SYMBOL(cpumask_next_and);
 44
 45/**
 46 * cpumask_any_but - return a "random" in a cpumask, but not this one.
 47 * @mask: the cpumask to search
 48 * @cpu: the cpu to ignore.
 49 *
 50 * Often used to find any cpu but smp_processor_id() in a mask.
 51 * Returns >= nr_cpu_ids if no cpus set.
 52 */
 53int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
 54{
 55	unsigned int i;
 56
 57	cpumask_check(cpu);
 58	for_each_cpu(i, mask)
 59		if (i != cpu)
 60			break;
 61	return i;
 62}
 63EXPORT_SYMBOL(cpumask_any_but);
 64
 65/**
 66 * cpumask_next_wrap - helper to implement for_each_cpu_wrap
 67 * @n: the cpu prior to the place to search
 68 * @mask: the cpumask pointer
 69 * @start: the start point of the iteration
 70 * @wrap: assume @n crossing @start terminates the iteration
 71 *
 72 * Returns >= nr_cpu_ids on completion
 73 *
 74 * Note: the @wrap argument is required for the start condition when
 75 * we cannot assume @start is set in @mask.
 76 */
 77int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap)
 78{
 79	int next;
 80
 81again:
 82	next = cpumask_next(n, mask);
 83
 84	if (wrap && n < start && next >= start) {
 85		return nr_cpumask_bits;
 86
 87	} else if (next >= nr_cpumask_bits) {
 88		wrap = true;
 89		n = -1;
 90		goto again;
 91	}
 92
 93	return next;
 94}
 95EXPORT_SYMBOL(cpumask_next_wrap);
 96
 97/* These are not inline because of header tangles. */
 98#ifdef CONFIG_CPUMASK_OFFSTACK
 99/**
100 * alloc_cpumask_var_node - allocate a struct cpumask on a given node
101 * @mask: pointer to cpumask_var_t where the cpumask is returned
102 * @flags: GFP_ flags
103 *
104 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
105 * a nop returning a constant 1 (in <linux/cpumask.h>)
106 * Returns TRUE if memory allocation succeeded, FALSE otherwise.
107 *
108 * In addition, mask will be NULL if this fails.  Note that gcc is
109 * usually smart enough to know that mask can never be NULL if
110 * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case
111 * too.
112 */
113bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
114{
115	*mask = kmalloc_node(cpumask_size(), flags, node);
116
117#ifdef CONFIG_DEBUG_PER_CPU_MAPS
118	if (!*mask) {
119		printk(KERN_ERR "=> alloc_cpumask_var: failed!\n");
120		dump_stack();
121	}
122#endif
123
124	return *mask != NULL;
125}
126EXPORT_SYMBOL(alloc_cpumask_var_node);
127
128bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
129{
130	return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
131}
132EXPORT_SYMBOL(zalloc_cpumask_var_node);
133
134/**
135 * alloc_cpumask_var - allocate a struct cpumask
136 * @mask: pointer to cpumask_var_t where the cpumask is returned
137 * @flags: GFP_ flags
138 *
139 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
140 * a nop returning a constant 1 (in <linux/cpumask.h>).
141 *
142 * See alloc_cpumask_var_node.
143 */
144bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
145{
146	return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE);
147}
148EXPORT_SYMBOL(alloc_cpumask_var);
149
150bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
151{
152	return alloc_cpumask_var(mask, flags | __GFP_ZERO);
153}
154EXPORT_SYMBOL(zalloc_cpumask_var);
155
156/**
157 * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena.
158 * @mask: pointer to cpumask_var_t where the cpumask is returned
159 *
160 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
161 * a nop (in <linux/cpumask.h>).
162 * Either returns an allocated (zero-filled) cpumask, or causes the
163 * system to panic.
164 */
165void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask)
166{
167	*mask = memblock_alloc(cpumask_size(), SMP_CACHE_BYTES);
168	if (!*mask)
169		panic("%s: Failed to allocate %u bytes\n", __func__,
170		      cpumask_size());
171}
172
173/**
174 * free_cpumask_var - frees memory allocated for a struct cpumask.
175 * @mask: cpumask to free
176 *
177 * This is safe on a NULL mask.
178 */
179void free_cpumask_var(cpumask_var_t mask)
180{
181	kfree(mask);
182}
183EXPORT_SYMBOL(free_cpumask_var);
184
185/**
186 * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var
187 * @mask: cpumask to free
188 */
189void __init free_bootmem_cpumask_var(cpumask_var_t mask)
190{
191	memblock_free_early(__pa(mask), cpumask_size());
192}
193#endif
194
195/**
196 * cpumask_local_spread - select the i'th cpu with local numa cpu's first
197 * @i: index number
198 * @node: local numa_node
199 *
200 * This function selects an online CPU according to a numa aware policy;
201 * local cpus are returned first, followed by non-local ones, then it
202 * wraps around.
203 *
204 * It's not very efficient, but useful for setup.
205 */
206unsigned int cpumask_local_spread(unsigned int i, int node)
207{
208	int cpu;
209
210	/* Wrap: we always want a cpu. */
211	i %= num_online_cpus();
212
213	if (node == NUMA_NO_NODE) {
214		for_each_cpu(cpu, cpu_online_mask)
215			if (i-- == 0)
216				return cpu;
217	} else {
218		/* NUMA first. */
219		for_each_cpu_and(cpu, cpumask_of_node(node), cpu_online_mask)
220			if (i-- == 0)
221				return cpu;
222
223		for_each_cpu(cpu, cpu_online_mask) {
224			/* Skip NUMA nodes, done above. */
225			if (cpumask_test_cpu(cpu, cpumask_of_node(node)))
226				continue;
227
228			if (i-- == 0)
229				return cpu;
230		}
231	}
232	BUG();
233}
234EXPORT_SYMBOL(cpumask_local_spread);
235
236static DEFINE_PER_CPU(int, distribute_cpu_mask_prev);
237
238/**
239 * Returns an arbitrary cpu within srcp1 & srcp2.
240 *
241 * Iterated calls using the same srcp1 and srcp2 will be distributed within
242 * their intersection.
243 *
244 * Returns >= nr_cpu_ids if the intersection is empty.
245 */
246int cpumask_any_and_distribute(const struct cpumask *src1p,
247			       const struct cpumask *src2p)
248{
249	int next, prev;
250
251	/* NOTE: our first selection will skip 0. */
252	prev = __this_cpu_read(distribute_cpu_mask_prev);
253
254	next = cpumask_next_and(prev, src1p, src2p);
255	if (next >= nr_cpu_ids)
256		next = cpumask_first_and(src1p, src2p);
257
258	if (next < nr_cpu_ids)
259		__this_cpu_write(distribute_cpu_mask_prev, next);
260
261	return next;
262}
263EXPORT_SYMBOL(cpumask_any_and_distribute);
264
265int cpumask_any_distribute(const struct cpumask *srcp)
266{
267	int next, prev;
268
269	/* NOTE: our first selection will skip 0. */
270	prev = __this_cpu_read(distribute_cpu_mask_prev);
271
272	next = cpumask_next(prev, srcp);
273	if (next >= nr_cpu_ids)
274		next = cpumask_first(srcp);
275
276	if (next < nr_cpu_ids)
277		__this_cpu_write(distribute_cpu_mask_prev, next);
278
279	return next;
280}
281EXPORT_SYMBOL(cpumask_any_distribute);

 
  1#include <linux/slab.h>
  2#include <linux/kernel.h>
  3#include <linux/bitops.h>
  4#include <linux/cpumask.h>
  5#include <linux/export.h>
  6#include <linux/bootmem.h>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  7
  8/**
  9 * cpumask_next_and - get the next cpu in *src1p & *src2p
 10 * @n: the cpu prior to the place to search (ie. return will be > @n)
 11 * @src1p: the first cpumask pointer
 12 * @src2p: the second cpumask pointer
 13 *
 14 * Returns >= nr_cpu_ids if no further cpus set in both.
 15 */
 16int cpumask_next_and(int n, const struct cpumask *src1p,
 17		     const struct cpumask *src2p)
 18{
 19	while ((n = cpumask_next(n, src1p)) < nr_cpu_ids)
 20		if (cpumask_test_cpu(n, src2p))
 21			break;
 22	return n;
 
 23}
 24EXPORT_SYMBOL(cpumask_next_and);
 25
 26/**
 27 * cpumask_any_but - return a "random" in a cpumask, but not this one.
 28 * @mask: the cpumask to search
 29 * @cpu: the cpu to ignore.
 30 *
 31 * Often used to find any cpu but smp_processor_id() in a mask.
 32 * Returns >= nr_cpu_ids if no cpus set.
 33 */
 34int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
 35{
 36	unsigned int i;
 37
 38	cpumask_check(cpu);
 39	for_each_cpu(i, mask)
 40		if (i != cpu)
 41			break;
 42	return i;
 43}
 44EXPORT_SYMBOL(cpumask_any_but);
 45
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 46/* These are not inline because of header tangles. */
 47#ifdef CONFIG_CPUMASK_OFFSTACK
 48/**
 49 * alloc_cpumask_var_node - allocate a struct cpumask on a given node
 50 * @mask: pointer to cpumask_var_t where the cpumask is returned
 51 * @flags: GFP_ flags
 52 *
 53 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
 54 * a nop returning a constant 1 (in <linux/cpumask.h>)
 55 * Returns TRUE if memory allocation succeeded, FALSE otherwise.
 56 *
 57 * In addition, mask will be NULL if this fails.  Note that gcc is
 58 * usually smart enough to know that mask can never be NULL if
 59 * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case
 60 * too.
 61 */
 62bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
 63{
 64	*mask = kmalloc_node(cpumask_size(), flags, node);
 65
 66#ifdef CONFIG_DEBUG_PER_CPU_MAPS
 67	if (!*mask) {
 68		printk(KERN_ERR "=> alloc_cpumask_var: failed!\n");
 69		dump_stack();
 70	}
 71#endif
 72
 73	return *mask != NULL;
 74}
 75EXPORT_SYMBOL(alloc_cpumask_var_node);
 76
 77bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
 78{
 79	return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
 80}
 81EXPORT_SYMBOL(zalloc_cpumask_var_node);
 82
 83/**
 84 * alloc_cpumask_var - allocate a struct cpumask
 85 * @mask: pointer to cpumask_var_t where the cpumask is returned
 86 * @flags: GFP_ flags
 87 *
 88 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
 89 * a nop returning a constant 1 (in <linux/cpumask.h>).
 90 *
 91 * See alloc_cpumask_var_node.
 92 */
 93bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
 94{
 95	return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE);
 96}
 97EXPORT_SYMBOL(alloc_cpumask_var);
 98
 99bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
100{
101	return alloc_cpumask_var(mask, flags | __GFP_ZERO);
102}
103EXPORT_SYMBOL(zalloc_cpumask_var);
104
105/**
106 * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena.
107 * @mask: pointer to cpumask_var_t where the cpumask is returned
108 *
109 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
110 * a nop (in <linux/cpumask.h>).
111 * Either returns an allocated (zero-filled) cpumask, or causes the
112 * system to panic.
113 */
114void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask)
115{
116	*mask = memblock_virt_alloc(cpumask_size(), 0);
 
 
 
117}
118
119/**
120 * free_cpumask_var - frees memory allocated for a struct cpumask.
121 * @mask: cpumask to free
122 *
123 * This is safe on a NULL mask.
124 */
125void free_cpumask_var(cpumask_var_t mask)
126{
127	kfree(mask);
128}
129EXPORT_SYMBOL(free_cpumask_var);
130
131/**
132 * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var
133 * @mask: cpumask to free
134 */
135void __init free_bootmem_cpumask_var(cpumask_var_t mask)
136{
137	memblock_free_early(__pa(mask), cpumask_size());
138}
139#endif
140
141/**
142 * cpumask_local_spread - select the i'th cpu with local numa cpu's first
143 * @i: index number
144 * @node: local numa_node
145 *
146 * This function selects an online CPU according to a numa aware policy;
147 * local cpus are returned first, followed by non-local ones, then it
148 * wraps around.
149 *
150 * It's not very efficient, but useful for setup.
151 */
152unsigned int cpumask_local_spread(unsigned int i, int node)
153{
154	int cpu;
155
156	/* Wrap: we always want a cpu. */
157	i %= num_online_cpus();
158
159	if (node == -1) {
160		for_each_cpu(cpu, cpu_online_mask)
161			if (i-- == 0)
162				return cpu;
163	} else {
164		/* NUMA first. */
165		for_each_cpu_and(cpu, cpumask_of_node(node), cpu_online_mask)
166			if (i-- == 0)
167				return cpu;
168
169		for_each_cpu(cpu, cpu_online_mask) {
170			/* Skip NUMA nodes, done above. */
171			if (cpumask_test_cpu(cpu, cpumask_of_node(node)))
172				continue;
173
174			if (i-- == 0)
175				return cpu;
176		}
177	}
178	BUG();
179}
180EXPORT_SYMBOL(cpumask_local_spread);