#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!
  ");
  		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);