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 struct cpumask tmp; 20 21 if (cpumask_and(&tmp, src1p, src2p)) 22 return cpumask_next(n, &tmp); 23 return nr_cpu_ids; 24 } 25 EXPORT_SYMBOL(cpumask_next_and); 26 27 /** 28 * cpumask_any_but - return a "random" in a cpumask, but not this one. 29 * @mask: the cpumask to search 30 * @cpu: the cpu to ignore. 31 * 32 * Often used to find any cpu but smp_processor_id() in a mask. 33 * Returns >= nr_cpu_ids if no cpus set. 34 */ 35 int cpumask_any_but(const struct cpumask *mask, unsigned int cpu) 36 { 37 unsigned int i; 38 39 cpumask_check(cpu); 40 for_each_cpu(i, mask) 41 if (i != cpu) 42 break; 43 return i; 44 } 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 */ 62 bool 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 } 75 EXPORT_SYMBOL(alloc_cpumask_var_node); 76 77 bool 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 } 81 EXPORT_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 */ 93 bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 94 { 95 return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE); 96 } 97 EXPORT_SYMBOL(alloc_cpumask_var); 98 99 bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 100 { 101 return alloc_cpumask_var(mask, flags | __GFP_ZERO); 102 } 103 EXPORT_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 */ 114 void __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 */ 125 void free_cpumask_var(cpumask_var_t mask) 126 { 127 kfree(mask); 128 } 129 EXPORT_SYMBOL(free_cpumask_var); 130 131 /** 132 * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var 133 * @mask: cpumask to free 134 */ 135 void __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_set_cpu_local_first - set i'th cpu with local numa cpu's first 143 * 144 * @i: index number 145 * @numa_node: local numa_node 146 * @dstp: cpumask with the relevant cpu bit set according to the policy 147 * 148 * This function sets the cpumask according to a numa aware policy. 149 * cpumask could be used as an affinity hint for the IRQ related to a 150 * queue. When the policy is to spread queues across cores - local cores 151 * first. 152 * 153 * Returns 0 on success, -ENOMEM for no memory, and -EAGAIN when failed to set 154 * the cpu bit and need to re-call the function. 155 */ 156 int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp) 157 { 158 cpumask_var_t mask; 159 int cpu; 160 int ret = 0; 161 162 if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) 163 return -ENOMEM; 164 165 i %= num_online_cpus(); 166 167 if (numa_node == -1 || !cpumask_of_node(numa_node)) { 168 /* Use all online cpu's for non numa aware system */ 169 cpumask_copy(mask, cpu_online_mask); 170 } else { 171 int n; 172 173 cpumask_and(mask, 174 cpumask_of_node(numa_node), cpu_online_mask); 175 176 n = cpumask_weight(mask); 177 if (i >= n) { 178 i -= n; 179 180 /* If index > number of local cpu's, mask out local 181 * cpu's 182 */ 183 cpumask_andnot(mask, cpu_online_mask, mask); 184 } 185 } 186 187 for_each_cpu(cpu, mask) { 188 if (--i < 0) 189 goto out; 190 } 191 192 ret = -EAGAIN; 193 194 out: 195 free_cpumask_var(mask); 196 197 if (!ret) 198 cpumask_set_cpu(cpu, dstp); 199 200 return ret; 201 } 202 EXPORT_SYMBOL(cpumask_set_cpu_local_first); 203