230 lines
5.8 KiB
C
Executable File
230 lines
5.8 KiB
C
Executable File
#include <linux/slab.h>
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#include <linux/kernel.h>
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#include <linux/bitops.h>
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#include <linux/cpumask.h>
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#include <linux/export.h>
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#include <linux/bootmem.h>
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int __first_cpu(const cpumask_t *srcp)
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{
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return min_t(int, NR_CPUS, find_first_bit(srcp->bits, NR_CPUS));
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}
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EXPORT_SYMBOL(__first_cpu);
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int __next_cpu(int n, const cpumask_t *srcp)
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{
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return min_t(int, NR_CPUS, find_next_bit(srcp->bits, NR_CPUS, n+1));
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}
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EXPORT_SYMBOL(__next_cpu);
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#if NR_CPUS > 64
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int __next_cpu_nr(int n, const cpumask_t *srcp)
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{
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return min_t(int, nr_cpu_ids,
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find_next_bit(srcp->bits, nr_cpu_ids, n+1));
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}
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EXPORT_SYMBOL(__next_cpu_nr);
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#endif
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/**
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* cpumask_next_and - get the next cpu in *src1p & *src2p
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* @n: the cpu prior to the place to search (ie. return will be > @n)
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* @src1p: the first cpumask pointer
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* @src2p: the second cpumask pointer
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*
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* Returns >= nr_cpu_ids if no further cpus set in both.
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*/
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int cpumask_next_and(int n, const struct cpumask *src1p,
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const struct cpumask *src2p)
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{
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while ((n = cpumask_next(n, src1p)) < nr_cpu_ids)
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if (cpumask_test_cpu(n, src2p))
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break;
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return n;
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}
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EXPORT_SYMBOL(cpumask_next_and);
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/**
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* cpumask_any_but - return a "random" in a cpumask, but not this one.
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* @mask: the cpumask to search
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* @cpu: the cpu to ignore.
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*
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* Often used to find any cpu but smp_processor_id() in a mask.
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* Returns >= nr_cpu_ids if no cpus set.
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*/
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int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
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{
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unsigned int i;
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cpumask_check(cpu);
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for_each_cpu(i, mask)
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if (i != cpu)
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break;
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return i;
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}
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/* These are not inline because of header tangles. */
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#ifdef CONFIG_CPUMASK_OFFSTACK
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/**
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* alloc_cpumask_var_node - allocate a struct cpumask on a given node
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* @mask: pointer to cpumask_var_t where the cpumask is returned
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* @flags: GFP_ flags
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*
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* Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
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* a nop returning a constant 1 (in <linux/cpumask.h>)
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* Returns TRUE if memory allocation succeeded, FALSE otherwise.
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*
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* In addition, mask will be NULL if this fails. Note that gcc is
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* usually smart enough to know that mask can never be NULL if
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* CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case
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* too.
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*/
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bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
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{
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*mask = kmalloc_node(cpumask_size(), flags, node);
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#ifdef CONFIG_DEBUG_PER_CPU_MAPS
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if (!*mask) {
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printk(KERN_ERR "=> alloc_cpumask_var: failed!\n");
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dump_stack();
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}
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#endif
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/* FIXME: Bandaid to save us from old primitives which go to NR_CPUS. */
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if (*mask) {
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unsigned char *ptr = (unsigned char *)cpumask_bits(*mask);
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unsigned int tail;
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tail = BITS_TO_LONGS(NR_CPUS - nr_cpumask_bits) * sizeof(long);
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memset(ptr + cpumask_size() - tail, 0, tail);
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}
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return *mask != NULL;
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}
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EXPORT_SYMBOL(alloc_cpumask_var_node);
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bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
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{
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return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
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}
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EXPORT_SYMBOL(zalloc_cpumask_var_node);
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/**
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* alloc_cpumask_var - allocate a struct cpumask
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* @mask: pointer to cpumask_var_t where the cpumask is returned
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* @flags: GFP_ flags
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*
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* Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
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* a nop returning a constant 1 (in <linux/cpumask.h>).
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*
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* See alloc_cpumask_var_node.
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*/
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bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
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{
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return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE);
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}
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EXPORT_SYMBOL(alloc_cpumask_var);
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bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
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{
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return alloc_cpumask_var(mask, flags | __GFP_ZERO);
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}
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EXPORT_SYMBOL(zalloc_cpumask_var);
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/**
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* alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena.
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* @mask: pointer to cpumask_var_t where the cpumask is returned
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*
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* Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
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* a nop (in <linux/cpumask.h>).
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* Either returns an allocated (zero-filled) cpumask, or causes the
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* system to panic.
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*/
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void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask)
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{
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*mask = memblock_virt_alloc(cpumask_size(), 0);
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}
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/**
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* free_cpumask_var - frees memory allocated for a struct cpumask.
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* @mask: cpumask to free
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*
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* This is safe on a NULL mask.
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*/
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void free_cpumask_var(cpumask_var_t mask)
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{
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kfree(mask);
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}
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EXPORT_SYMBOL(free_cpumask_var);
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/**
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* free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var
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* @mask: cpumask to free
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*/
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void __init free_bootmem_cpumask_var(cpumask_var_t mask)
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{
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memblock_free_early(__pa(mask), cpumask_size());
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}
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#endif
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/**
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* cpumask_set_cpu_local_first - set i'th cpu with local numa cpu's first
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*
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* @i: index number
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* @numa_node: local numa_node
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* @dstp: cpumask with the relevant cpu bit set according to the policy
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*
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* This function sets the cpumask according to a numa aware policy.
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* cpumask could be used as an affinity hint for the IRQ related to a
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* queue. When the policy is to spread queues across cores - local cores
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* first.
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*
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* Returns 0 on success, -ENOMEM for no memory, and -EAGAIN when failed to set
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* the cpu bit and need to re-call the function.
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*/
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int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp)
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{
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cpumask_var_t mask;
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int cpu;
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int ret = 0;
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if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
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return -ENOMEM;
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i %= num_online_cpus();
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if (numa_node == -1 || !cpumask_of_node(numa_node)) {
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/* Use all online cpu's for non numa aware system */
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cpumask_copy(mask, cpu_online_mask);
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} else {
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int n;
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cpumask_and(mask,
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cpumask_of_node(numa_node), cpu_online_mask);
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n = cpumask_weight(mask);
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if (i >= n) {
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i -= n;
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/* If index > number of local cpu's, mask out local
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* cpu's
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*/
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cpumask_andnot(mask, cpu_online_mask, mask);
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}
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}
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for_each_cpu(cpu, mask) {
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if (--i < 0)
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goto out;
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}
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ret = -EAGAIN;
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out:
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free_cpumask_var(mask);
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if (!ret)
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cpumask_set_cpu(cpu, dstp);
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return ret;
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}
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EXPORT_SYMBOL(cpumask_set_cpu_local_first);
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