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 */ 16 int 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 } 24 EXPORT_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 */ 34 int 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 } 44 EXPORT_SYMBOL(cpumask_any_but); 45 46 /** 47 * cpumask_next_wrap - helper to implement for_each_cpu_wrap 48 * @n: the cpu prior to the place to search 49 * @mask: the cpumask pointer 50 * @start: the start point of the iteration 51 * @wrap: assume @n crossing @start terminates the iteration 52 * 53 * Returns >= nr_cpu_ids on completion 54 * 55 * Note: the @wrap argument is required for the start condition when 56 * we cannot assume @start is set in @mask. 57 */ 58 int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap) 59 { 60 int next; 61 62 again: 63 next = cpumask_next(n, mask); 64 65 if (wrap && n < start && next >= start) { 66 return nr_cpumask_bits; 67 68 } else if (next >= nr_cpumask_bits) { 69 wrap = true; 70 n = -1; 71 goto again; 72 } 73 74 return next; 75 } 76 EXPORT_SYMBOL(cpumask_next_wrap); 77 78 /* These are not inline because of header tangles. */ 79 #ifdef CONFIG_CPUMASK_OFFSTACK 80 /** 81 * alloc_cpumask_var_node - allocate a struct cpumask on a given node 82 * @mask: pointer to cpumask_var_t where the cpumask is returned 83 * @flags: GFP_ flags 84 * 85 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is 86 * a nop returning a constant 1 (in <linux/cpumask.h>) 87 * Returns TRUE if memory allocation succeeded, FALSE otherwise. 88 * 89 * In addition, mask will be NULL if this fails. Note that gcc is 90 * usually smart enough to know that mask can never be NULL if 91 * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case 92 * too. 93 */ 94 bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) 95 { 96 *mask = kmalloc_node(cpumask_size(), flags, node); 97 98 #ifdef CONFIG_DEBUG_PER_CPU_MAPS 99 if (!*mask) { 100 printk(KERN_ERR "=> alloc_cpumask_var: failed!\n"); 101 dump_stack(); 102 } 103 #endif 104 105 return *mask != NULL; 106 } 107 EXPORT_SYMBOL(alloc_cpumask_var_node); 108 109 bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) 110 { 111 return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node); 112 } 113 EXPORT_SYMBOL(zalloc_cpumask_var_node); 114 115 /** 116 * alloc_cpumask_var - allocate a struct cpumask 117 * @mask: pointer to cpumask_var_t where the cpumask is returned 118 * @flags: GFP_ flags 119 * 120 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is 121 * a nop returning a constant 1 (in <linux/cpumask.h>). 122 * 123 * See alloc_cpumask_var_node. 124 */ 125 bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 126 { 127 return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE); 128 } 129 EXPORT_SYMBOL(alloc_cpumask_var); 130 131 bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 132 { 133 return alloc_cpumask_var(mask, flags | __GFP_ZERO); 134 } 135 EXPORT_SYMBOL(zalloc_cpumask_var); 136 137 /** 138 * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena. 139 * @mask: pointer to cpumask_var_t where the cpumask is returned 140 * 141 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is 142 * a nop (in <linux/cpumask.h>). 143 * Either returns an allocated (zero-filled) cpumask, or causes the 144 * system to panic. 145 */ 146 void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask) 147 { 148 *mask = memblock_virt_alloc(cpumask_size(), 0); 149 } 150 151 /** 152 * free_cpumask_var - frees memory allocated for a struct cpumask. 153 * @mask: cpumask to free 154 * 155 * This is safe on a NULL mask. 156 */ 157 void free_cpumask_var(cpumask_var_t mask) 158 { 159 kfree(mask); 160 } 161 EXPORT_SYMBOL(free_cpumask_var); 162 163 /** 164 * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var 165 * @mask: cpumask to free 166 */ 167 void __init free_bootmem_cpumask_var(cpumask_var_t mask) 168 { 169 memblock_free_early(__pa(mask), cpumask_size()); 170 } 171 #endif 172 173 /** 174 * cpumask_local_spread - select the i'th cpu with local numa cpu's first 175 * @i: index number 176 * @node: local numa_node 177 * 178 * This function selects an online CPU according to a numa aware policy; 179 * local cpus are returned first, followed by non-local ones, then it 180 * wraps around. 181 * 182 * It's not very efficient, but useful for setup. 183 */ 184 unsigned int cpumask_local_spread(unsigned int i, int node) 185 { 186 int cpu; 187 188 /* Wrap: we always want a cpu. */ 189 i %= num_online_cpus(); 190 191 if (node == -1) { 192 for_each_cpu(cpu, cpu_online_mask) 193 if (i-- == 0) 194 return cpu; 195 } else { 196 /* NUMA first. */ 197 for_each_cpu_and(cpu, cpumask_of_node(node), cpu_online_mask) 198 if (i-- == 0) 199 return cpu; 200 201 for_each_cpu(cpu, cpu_online_mask) { 202 /* Skip NUMA nodes, done above. */ 203 if (cpumask_test_cpu(cpu, cpumask_of_node(node))) 204 continue; 205 206 if (i-- == 0) 207 return cpu; 208 } 209 } 210 BUG(); 211 } 212 EXPORT_SYMBOL(cpumask_local_spread); 213