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