[net-next-2.6.git] / lib / iommu-helper.c

/*
 * IOMMU helper functions for the free area management
 */

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

static unsigned long find_next_zero_area(unsigned long *map,
					 unsigned long size,
					 unsigned long start,
					 unsigned int nr,
					 unsigned long align_mask)
{
	unsigned long index, end, i;
again:
	index = find_next_zero_bit(map, size, start);

	/* Align allocation */
	index = (index + align_mask) & ~align_mask;

	end = index + nr;
	if (end >= size)
		return -1;
	for (i = index; i < end; i++) {
		if (test_bit(i, map)) {
			start = i+1;
			goto again;
		}
	}
	return index;
}

void iommu_area_reserve(unsigned long *map, unsigned long i, int len)
{
	unsigned long end = i + len;
	while (i < end) {
		__set_bit(i, map);
		i++;
	}
}

int iommu_is_span_boundary(unsigned int index, unsigned int nr,
			   unsigned long shift,
			   unsigned long boundary_size)
{
	BUG_ON(!is_power_of_2(boundary_size));

	shift = (shift + index) & (boundary_size - 1);
	return shift + nr > boundary_size;
}

unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
			       unsigned long start, unsigned int nr,
			       unsigned long shift, unsigned long boundary_size,
			       unsigned long align_mask)
{
	unsigned long index;
again:
	index = find_next_zero_area(map, size, start, nr, align_mask);
	if (index != -1) {
		if (iommu_is_span_boundary(index, nr, shift, boundary_size)) {
			/* we could do more effectively */
			start = index + 1;
			goto again;
		}
		iommu_area_reserve(map, index, nr);
	}
	return index;
}
EXPORT_SYMBOL(iommu_area_alloc);

void iommu_area_free(unsigned long *map, unsigned long start, unsigned int nr)
{
	unsigned long end = start + nr;

	while (start < end) {
		__clear_bit(start, map);
		start++;
	}
}
EXPORT_SYMBOL(iommu_area_free);

unsigned long iommu_num_pages(unsigned long addr, unsigned long len,
			      unsigned long io_page_size)
{
	unsigned long size = (addr & (io_page_size - 1)) + len;

	return DIV_ROUND_UP(size, io_page_size);
}
EXPORT_SYMBOL(iommu_num_pages);
Commit	Line	Data
0291df8c FT	1	/*
	2	* IOMMU helper functions for the free area management
	3	*/
	4
	5	#include <linux/module.h>
	6	#include <linux/bitops.h>
	7
	8	static unsigned long find_next_zero_area(unsigned long *map,
	9	unsigned long size,
	10	unsigned long start,
	11	unsigned int nr,
	12	unsigned long align_mask)
	13	{
	14	unsigned long index, end, i;
	15	again:
	16	index = find_next_zero_bit(map, size, start);
	17
	18	/* Align allocation */
	19	index = (index + align_mask) & ~align_mask;
	20
	21	end = index + nr;
	22	if (end >= size)
	23	return -1;
	24	for (i = index; i < end; i++) {
	25	if (test_bit(i, map)) {
	26	start = i+1;
	27	goto again;
	28	}
	29	}
	30	return index;
	31	}
	32
d26dbc5c	33	void iommu_area_reserve(unsigned long *map, unsigned long i, int len)
0291df8c FT	34	{
	35	unsigned long end = i + len;
	36	while (i < end) {
	37	__set_bit(i, map);
	38	i++;
	39	}
	40	}
	41
3715863a FT	42	int iommu_is_span_boundary(unsigned int index, unsigned int nr,
	43	unsigned long shift,
	44	unsigned long boundary_size)
0291df8c	45	{
3715863a FT	46	BUG_ON(!is_power_of_2(boundary_size));
3715863a FT	47
0291df8c FT	48	shift = (shift + index) & (boundary_size - 1);
	49	return shift + nr > boundary_size;
	50	}
	51
	52	unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
	53	unsigned long start, unsigned int nr,
	54	unsigned long shift, unsigned long boundary_size,
	55	unsigned long align_mask)
	56	{
	57	unsigned long index;
	58	again:
	59	index = find_next_zero_area(map, size, start, nr, align_mask);
	60	if (index != -1) {
3715863a	61	if (iommu_is_span_boundary(index, nr, shift, boundary_size)) {
0291df8c FT	62	/* we could do more effectively */
	63	start = index + 1;
	64	goto again;
	65	}
d26dbc5c	66	iommu_area_reserve(map, index, nr);
0291df8c FT	67	}
	68	return index;
	69	}
	70	EXPORT_SYMBOL(iommu_area_alloc);
	71
	72	void iommu_area_free(unsigned long *map, unsigned long start, unsigned int nr)
	73	{
	74	unsigned long end = start + nr;
	75
	76	while (start < end) {
	77	__clear_bit(start, map);
	78	start++;
	79	}
	80	}
	81	EXPORT_SYMBOL(iommu_area_free);
56d93660 JR	82
	83	unsigned long iommu_num_pages(unsigned long addr, unsigned long len,
	84	unsigned long io_page_size)
	85	{
	86	unsigned long size = (addr & (io_page_size - 1)) + len;
	87
	88	return DIV_ROUND_UP(size, io_page_size);
	89	}
	90	EXPORT_SYMBOL(iommu_num_pages);