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