#include <stdio.h>
#include <linux/bitops.h>

#define BITS_PER_LONG	32
#define NR_CPUS 3
#define printk(x...)	printf(x)

#define BITS_TO_LONGS(bits) \
	(((bits)+BITS_PER_LONG-1)/BITS_PER_LONG)
#define DECLARE_BITMAP(name,bits) \
	unsigned long name[BITS_TO_LONGS(bits)]
#define CLEAR_BITMAP(name,bits) \
	memset(name, 0, BITS_TO_LONGS(bits)*sizeof(unsigned long))

static inline void bitmap_or(volatile unsigned long *dst, const volatile unsigned long *bitmap1,
				const volatile unsigned long *bitmap2, int bits)
{
	int k;

	for (k = 0; k < BITS_TO_LONGS(bits); ++k)
		dst[k] = bitmap1[k] | bitmap2[k];
}

#define cpu_set(cpu, map)	set_bit(cpu, (map).mask)
#define cpus_or(dst,src1,src2)	bitmap_or((dst).mask, (src1).mask, (src2).mask, NR_CPUS)
#define cpus_coerce(map)	((map).mask[0])

#define CPU_ARRAY_SIZE		BITS_TO_LONGS(NR_CPUS)

#define CPU_MASK_ALL	{ {[0 ... CPU_ARRAY_SIZE-1] = ~0UL} }
#define CPU_MASK_NONE	{ {[0 ... CPU_ARRAY_SIZE-1] =  0UL} }

#define cpumask_of_cpu(cpu)	({ cpumask_t __cpu_mask = CPU_MASK_NONE;\
					cpu_set(cpu, __cpu_mask);	\
					__cpu_mask;			\
				})

struct cpumask
{
	unsigned long mask[CPU_ARRAY_SIZE];
};

typedef struct cpumask cpumask_t;

static inline cpumask_t apicid_to_cpu_present(int phys_apicid)
{
	return cpumask_of_cpu(phys_apicid);
}

int main(int argc, char **argv)
{
	int bios_apicids[] = { 0, 3, 4, -1}, i, apicid;
	cpumask_t phys_cpu_present_map = CPU_MASK_NONE, tmp;

	for (i = 0; bios_apicids[i] != -1; i++) {
		apicid = bios_apicids[i];
		tmp = apicid_to_cpu_present(apicid);
		printk("%s: tmp %lx\n", __FUNCTION__, cpus_coerce(tmp));
		printk("%s: phys_cpu_present_map before %lx\n",
			__FUNCTION__, cpus_coerce(phys_cpu_present_map));
		cpus_or(phys_cpu_present_map, phys_cpu_present_map, tmp);
		printk("%s: phys_cpu_present_map after %lx\n",
			__FUNCTION__, cpus_coerce(phys_cpu_present_map));
	}
	return 0;
}