[deliverable/linux.git] / arch / powerpc / sysdev / msi_bitmap.c

/*
 * Copyright 2006-2008, Michael Ellerman, IBM Corporation.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; version 2 of the
 * License.
 *
 */

#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/bitmap.h>
#include <linux/bootmem.h>
#include <asm/msi_bitmap.h>
#include <asm/setup.h>

int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num)
{
	unsigned long flags;
	int offset, order = get_count_order(num);

	spin_lock_irqsave(&bmp->lock, flags);

	offset = bitmap_find_next_zero_area(bmp->bitmap, bmp->irq_count, 0,
					    num, (1 << order) - 1);
	if (offset > bmp->irq_count)
		goto err;

	bitmap_set(bmp->bitmap, offset, num);
	spin_unlock_irqrestore(&bmp->lock, flags);

	pr_debug("msi_bitmap: allocated 0x%x at offset 0x%x\n", num, offset);

	return offset;
err:
	spin_unlock_irqrestore(&bmp->lock, flags);
	return -ENOMEM;
}
EXPORT_SYMBOL(msi_bitmap_alloc_hwirqs);

void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset,
			    unsigned int num)
{
	unsigned long flags;

	pr_debug("msi_bitmap: freeing 0x%x at offset 0x%x\n",
		 num, offset);

	spin_lock_irqsave(&bmp->lock, flags);
	bitmap_clear(bmp->bitmap, offset, num);
	spin_unlock_irqrestore(&bmp->lock, flags);
}
EXPORT_SYMBOL(msi_bitmap_free_hwirqs);

void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq)
{
	unsigned long flags;

	pr_debug("msi_bitmap: reserving hwirq 0x%x\n", hwirq);

	spin_lock_irqsave(&bmp->lock, flags);
	bitmap_allocate_region(bmp->bitmap, hwirq, 0);
	spin_unlock_irqrestore(&bmp->lock, flags);
}

/**
 * msi_bitmap_reserve_dt_hwirqs - Reserve irqs specified in the device tree.
 * @bmp: pointer to the MSI bitmap.
 *
 * Looks in the device tree to see if there is a property specifying which
 * irqs can be used for MSI. If found those irqs reserved in the device tree
 * are reserved in the bitmap.
 *
 * Returns 0 for success, < 0 if there was an error, and > 0 if no property
 * was found in the device tree.
 **/
int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp)
{
	int i, j, len;
	const u32 *p;

	if (!bmp->of_node)
		return 1;

	p = of_get_property(bmp->of_node, "msi-available-ranges", &len);
	if (!p) {
		pr_debug("msi_bitmap: no msi-available-ranges property " \
			 "found on %s\n", bmp->of_node->full_name);
		return 1;
	}

	if (len % (2 * sizeof(u32)) != 0) {
		printk(KERN_WARNING "msi_bitmap: Malformed msi-available-ranges"
		       " property on %s\n", bmp->of_node->full_name);
		return -EINVAL;
	}

	bitmap_allocate_region(bmp->bitmap, 0, get_count_order(bmp->irq_count));

	spin_lock(&bmp->lock);

	/* Format is: (<u32 start> <u32 count>)+ */
	len /= 2 * sizeof(u32);
	for (i = 0; i < len; i++, p += 2) {
		for (j = 0; j < *(p + 1); j++)
			bitmap_release_region(bmp->bitmap, *p + j, 0);
	}

	spin_unlock(&bmp->lock);

	return 0;
}

int __init_refok msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count,
		     struct device_node *of_node)
{
	int size;

	if (!irq_count)
		return -EINVAL;

	size = BITS_TO_LONGS(irq_count) * sizeof(long);
	pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size);

	bmp->bitmap_from_slab = slab_is_available();
	if (bmp->bitmap_from_slab)
		bmp->bitmap = kzalloc(size, GFP_KERNEL);
	else {
		bmp->bitmap = memblock_virt_alloc(size, 0);
		/* the bitmap won't be freed from memblock allocator */
		kmemleak_not_leak(bmp->bitmap);
	}

	if (!bmp->bitmap) {
		pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n");
		return -ENOMEM;
	}

	/* We zalloc'ed the bitmap, so all irqs are free by default */
	spin_lock_init(&bmp->lock);
	bmp->of_node = of_node_get(of_node);
	bmp->irq_count = irq_count;

	return 0;
}

void msi_bitmap_free(struct msi_bitmap *bmp)
{
	if (bmp->bitmap_from_slab)
		kfree(bmp->bitmap);
	of_node_put(bmp->of_node);
	bmp->bitmap = NULL;
}

#ifdef CONFIG_MSI_BITMAP_SELFTEST

static void __init test_basics(void)
{
	struct msi_bitmap bmp;
	int rc, i, size = 512;

	/* Can't allocate a bitmap of 0 irqs */
	WARN_ON(msi_bitmap_alloc(&bmp, 0, NULL) == 0);

	/* of_node may be NULL */
	WARN_ON(msi_bitmap_alloc(&bmp, size, NULL));

	/* Should all be free by default */
	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));

	/* With no node, there's no msi-available-ranges, so expect > 0 */
	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);

	/* Should all still be free */
	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));

	/* Check we can fill it up and then no more */
	for (i = 0; i < size; i++)
		WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0);

	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0);

	/* Should all be allocated */
	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, 0) >= 0);

	/* And if we free one we can then allocate another */
	msi_bitmap_free_hwirqs(&bmp, size / 2, 1);
	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) != size / 2);

	/* Free most of them for the alignment tests */
	msi_bitmap_free_hwirqs(&bmp, 3, size - 3);

	/* Check we get a naturally aligned offset */
	rc = msi_bitmap_alloc_hwirqs(&bmp, 2);
	WARN_ON(rc < 0 && rc % 2 != 0);
	rc = msi_bitmap_alloc_hwirqs(&bmp, 4);
	WARN_ON(rc < 0 && rc % 4 != 0);
	rc = msi_bitmap_alloc_hwirqs(&bmp, 8);
	WARN_ON(rc < 0 && rc % 8 != 0);
	rc = msi_bitmap_alloc_hwirqs(&bmp, 9);
	WARN_ON(rc < 0 && rc % 16 != 0);
	rc = msi_bitmap_alloc_hwirqs(&bmp, 3);
	WARN_ON(rc < 0 && rc % 4 != 0);
	rc = msi_bitmap_alloc_hwirqs(&bmp, 7);
	WARN_ON(rc < 0 && rc % 8 != 0);
	rc = msi_bitmap_alloc_hwirqs(&bmp, 121);
	WARN_ON(rc < 0 && rc % 128 != 0);

	msi_bitmap_free(&bmp);

	/* Clients may WARN_ON bitmap == NULL for "not-allocated" */
	WARN_ON(bmp.bitmap != NULL);
}

static void __init test_of_node(void)
{
	u32 prop_data[] = { 10, 10, 25, 3, 40, 1, 100, 100, 200, 20 };
	const char *expected_str = "0-9,20-24,28-39,41-99,220-255";
	char *prop_name = "msi-available-ranges";
	char *node_name = "/fakenode";
	struct device_node of_node;
	struct property prop;
	struct msi_bitmap bmp;
	int size = 256;
	DECLARE_BITMAP(expected, size);

	/* There should really be a struct device_node allocator */
	memset(&of_node, 0, sizeof(of_node));
	of_node_init(&of_node);
	of_node.full_name = node_name;

	WARN_ON(msi_bitmap_alloc(&bmp, size, &of_node));

	/* No msi-available-ranges, so expect > 0 */
	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);

	/* Should all still be free */
	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));

	/* Now create a fake msi-available-ranges property */

	/* There should really .. oh whatever */
	memset(&prop, 0, sizeof(prop));
	prop.name = prop_name;
	prop.value = &prop_data;
	prop.length = sizeof(prop_data);

	of_node.properties = &prop;

	/* msi-available-ranges, so expect == 0 */
	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp));

	/* Check we got the expected result */
	WARN_ON(bitmap_parselist(expected_str, expected, size));
	WARN_ON(!bitmap_equal(expected, bmp.bitmap, size));

	msi_bitmap_free(&bmp);
	kfree(bmp.bitmap);
}

static int __init msi_bitmap_selftest(void)
{
	printk(KERN_DEBUG "Running MSI bitmap self-tests ...\n");

	test_basics();
	test_of_node();

	return 0;
}
late_initcall(msi_bitmap_selftest);
#endif /* CONFIG_MSI_BITMAP_SELFTEST */
Commit	Line	Data
7e302869 ME	1	/*
	2	* Copyright 2006-2008, Michael Ellerman, IBM Corporation.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation; version 2 of the
	7	* License.
	8	*
	9	*/
	10
5a0e3ad6	11	#include <linux/slab.h>
7e302869 ME	12	#include <linux/kernel.h>
7e302869 ME	13	#include <linux/bitmap.h>
cb2d3883	14	#include <linux/bootmem.h>
7e302869	15	#include <asm/msi_bitmap.h>
ae3a197e	16	#include <asm/setup.h>
7e302869 ME	17
	18	int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num)
	19	{
	20	unsigned long flags;
	21	int offset, order = get_count_order(num);
	22
	23	spin_lock_irqsave(&bmp->lock, flags);
b0345bbc IM	24
	25	offset = bitmap_find_next_zero_area(bmp->bitmap, bmp->irq_count, 0,
	26	num, (1 << order) - 1);
	27	if (offset > bmp->irq_count)
	28	goto err;
	29
	30	bitmap_set(bmp->bitmap, offset, num);
7e302869 ME	31	spin_unlock_irqrestore(&bmp->lock, flags);
7e302869 ME	32
b0345bbc	33	pr_debug("msi_bitmap: allocated 0x%x at offset 0x%x\n", num, offset);
7e302869 ME	34
7e302869 ME	35	return offset;
b0345bbc IM	36	err:
	37	spin_unlock_irqrestore(&bmp->lock, flags);
	38	return -ENOMEM;
7e302869	39	}
b0345bbc	40	EXPORT_SYMBOL(msi_bitmap_alloc_hwirqs);
7e302869 ME	41
	42	void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset,
	43	unsigned int num)
	44	{
	45	unsigned long flags;
7e302869	46
b0345bbc IM	47	pr_debug("msi_bitmap: freeing 0x%x at offset 0x%x\n",
b0345bbc IM	48	num, offset);
7e302869 ME	49
7e302869 ME	50	spin_lock_irqsave(&bmp->lock, flags);
b0345bbc	51	bitmap_clear(bmp->bitmap, offset, num);
7e302869 ME	52	spin_unlock_irqrestore(&bmp->lock, flags);
7e302869 ME	53	}
b0345bbc	54	EXPORT_SYMBOL(msi_bitmap_free_hwirqs);
7e302869 ME	55
	56	void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq)
	57	{
	58	unsigned long flags;
	59
	60	pr_debug("msi_bitmap: reserving hwirq 0x%x\n", hwirq);
	61
	62	spin_lock_irqsave(&bmp->lock, flags);
	63	bitmap_allocate_region(bmp->bitmap, hwirq, 0);
	64	spin_unlock_irqrestore(&bmp->lock, flags);
	65	}
	66
	67	/**
	68	* msi_bitmap_reserve_dt_hwirqs - Reserve irqs specified in the device tree.
	69	* @bmp: pointer to the MSI bitmap.
	70	*
	71	* Looks in the device tree to see if there is a property specifying which
	72	* irqs can be used for MSI. If found those irqs reserved in the device tree
	73	* are reserved in the bitmap.
	74	*
	75	* Returns 0 for success, < 0 if there was an error, and > 0 if no property
	76	* was found in the device tree.
	77	**/
	78	int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp)
	79	{
	80	int i, j, len;
	81	const u32 *p;
	82
	83	if (!bmp->of_node)
	84	return 1;
	85
	86	p = of_get_property(bmp->of_node, "msi-available-ranges", &len);
	87	if (!p) {
	88	pr_debug("msi_bitmap: no msi-available-ranges property " \
	89	"found on %s\n", bmp->of_node->full_name);
	90	return 1;
	91	}
	92
	93	if (len % (2 * sizeof(u32)) != 0) {
	94	printk(KERN_WARNING "msi_bitmap: Malformed msi-available-ranges"
	95	" property on %s\n", bmp->of_node->full_name);
	96	return -EINVAL;
	97	}
	98
	99	bitmap_allocate_region(bmp->bitmap, 0, get_count_order(bmp->irq_count));
	100
	101	spin_lock(&bmp->lock);
	102
	103	/* Format is: (<u32 start> <u32 count>)+ */
	104	len /= 2 * sizeof(u32);
	105	for (i = 0; i < len; i++, p += 2) {
	106	for (j = 0; j < *(p + 1); j++)
	107	bitmap_release_region(bmp->bitmap, *p + j, 0);
	108	}
	109
	110	spin_unlock(&bmp->lock);
	111
	112	return 0;
	113	}
	114
ccde64b5	115	int __init_refok msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count,
7e302869 ME	116	struct device_node *of_node)
	117	{
	118	int size;
	119
	120	if (!irq_count)
	121	return -EINVAL;
	122
	123	size = BITS_TO_LONGS(irq_count) * sizeof(long);
	124	pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size);
	125
cb2d3883 DK	126	bmp->bitmap_from_slab = slab_is_available();
	127	if (bmp->bitmap_from_slab)
	128	bmp->bitmap = kzalloc(size, GFP_KERNEL);
	129	else {
	130	bmp->bitmap = memblock_virt_alloc(size, 0);
	131	/* the bitmap won't be freed from memblock allocator */
	132	kmemleak_not_leak(bmp->bitmap);
	133	}
	134
7e302869 ME	135	if (!bmp->bitmap) {
	136	pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n");
	137	return -ENOMEM;
	138	}
	139
	140	/* We zalloc'ed the bitmap, so all irqs are free by default */
	141	spin_lock_init(&bmp->lock);
	142	bmp->of_node = of_node_get(of_node);
	143	bmp->irq_count = irq_count;
	144
	145	return 0;
	146	}
	147
	148	void msi_bitmap_free(struct msi_bitmap *bmp)
	149	{
cb2d3883 DK	150	if (bmp->bitmap_from_slab)
cb2d3883 DK	151	kfree(bmp->bitmap);
7e302869 ME	152	of_node_put(bmp->of_node);
	153	bmp->bitmap = NULL;
	154	}
	155
	156	#ifdef CONFIG_MSI_BITMAP_SELFTEST
	157
e51df2c1	158	static void __init test_basics(void)
7e302869 ME	159	{
7e302869 ME	160	struct msi_bitmap bmp;
695911fb	161	int rc, i, size = 512;
7e302869 ME	162
7e302869 ME	163	/* Can't allocate a bitmap of 0 irqs */
4a77f2bd	164	WARN_ON(msi_bitmap_alloc(&bmp, 0, NULL) == 0);
7e302869 ME	165
7e302869 ME	166	/* of_node may be NULL */
4a77f2bd	167	WARN_ON(msi_bitmap_alloc(&bmp, size, NULL));
7e302869 ME	168
7e302869 ME	169	/* Should all be free by default */
4a77f2bd	170	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
7e302869 ME	171	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
	172
	173	/* With no node, there's no msi-available-ranges, so expect > 0 */
4a77f2bd	174	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);
7e302869 ME	175
7e302869 ME	176	/* Should all still be free */
4a77f2bd	177	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
7e302869 ME	178	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
	179
	180	/* Check we can fill it up and then no more */
	181	for (i = 0; i < size; i++)
4a77f2bd	182	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0);
7e302869	183
4a77f2bd	184	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0);
7e302869 ME	185
7e302869 ME	186	/* Should all be allocated */
4a77f2bd	187	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, 0) >= 0);
7e302869 ME	188
	189	/* And if we free one we can then allocate another */
	190	msi_bitmap_free_hwirqs(&bmp, size / 2, 1);
4a77f2bd	191	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) != size / 2);
7e302869	192
695911fb ME	193	/* Free most of them for the alignment tests */
	194	msi_bitmap_free_hwirqs(&bmp, 3, size - 3);
	195
b0345bbc	196	/* Check we get a naturally aligned offset */
695911fb	197	rc = msi_bitmap_alloc_hwirqs(&bmp, 2);
4a77f2bd	198	WARN_ON(rc < 0 && rc % 2 != 0);
695911fb	199	rc = msi_bitmap_alloc_hwirqs(&bmp, 4);
4a77f2bd	200	WARN_ON(rc < 0 && rc % 4 != 0);
695911fb	201	rc = msi_bitmap_alloc_hwirqs(&bmp, 8);
4a77f2bd	202	WARN_ON(rc < 0 && rc % 8 != 0);
695911fb	203	rc = msi_bitmap_alloc_hwirqs(&bmp, 9);
4a77f2bd	204	WARN_ON(rc < 0 && rc % 16 != 0);
695911fb	205	rc = msi_bitmap_alloc_hwirqs(&bmp, 3);
4a77f2bd	206	WARN_ON(rc < 0 && rc % 4 != 0);
695911fb	207	rc = msi_bitmap_alloc_hwirqs(&bmp, 7);
4a77f2bd	208	WARN_ON(rc < 0 && rc % 8 != 0);
695911fb	209	rc = msi_bitmap_alloc_hwirqs(&bmp, 121);
4a77f2bd	210	WARN_ON(rc < 0 && rc % 128 != 0);
b0345bbc	211
7e302869 ME	212	msi_bitmap_free(&bmp);
7e302869 ME	213
4a77f2bd ME	214	/* Clients may WARN_ON bitmap == NULL for "not-allocated" */
4a77f2bd ME	215	WARN_ON(bmp.bitmap != NULL);
7e302869 ME	216	}
7e302869 ME	217
e51df2c1	218	static void __init test_of_node(void)
7e302869 ME	219	{
	220	u32 prop_data[] = { 10, 10, 25, 3, 40, 1, 100, 100, 200, 20 };
	221	const char *expected_str = "0-9,20-24,28-39,41-99,220-255";
	222	char *prop_name = "msi-available-ranges";
	223	char *node_name = "/fakenode";
	224	struct device_node of_node;
	225	struct property prop;
	226	struct msi_bitmap bmp;
	227	int size = 256;
	228	DECLARE_BITMAP(expected, size);
	229
	230	/* There should really be a struct device_node allocator */
	231	memset(&of_node, 0, sizeof(of_node));
e47ff70a	232	of_node_init(&of_node);
7e302869 ME	233	of_node.full_name = node_name;
7e302869 ME	234
4a77f2bd	235	WARN_ON(msi_bitmap_alloc(&bmp, size, &of_node));
7e302869 ME	236
7e302869 ME	237	/* No msi-available-ranges, so expect > 0 */
4a77f2bd	238	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);
7e302869 ME	239
7e302869 ME	240	/* Should all still be free */
4a77f2bd	241	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
7e302869 ME	242	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
	243
	244	/* Now create a fake msi-available-ranges property */
	245
	246	/* There should really .. oh whatever */
	247	memset(&prop, 0, sizeof(prop));
	248	prop.name = prop_name;
	249	prop.value = &prop_data;
	250	prop.length = sizeof(prop_data);
	251
	252	of_node.properties = &prop;
	253
	254	/* msi-available-ranges, so expect == 0 */
4a77f2bd	255	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp));
7e302869 ME	256
7e302869 ME	257	/* Check we got the expected result */
4a77f2bd ME	258	WARN_ON(bitmap_parselist(expected_str, expected, size));
4a77f2bd ME	259	WARN_ON(!bitmap_equal(expected, bmp.bitmap, size));
7e302869 ME	260
	261	msi_bitmap_free(&bmp);
	262	kfree(bmp.bitmap);
	263	}
	264
e51df2c1	265	static int __init msi_bitmap_selftest(void)
7e302869 ME	266	{
	267	printk(KERN_DEBUG "Running MSI bitmap self-tests ...\n");
	268
	269	test_basics();
	270	test_of_node();
	271
	272	return 0;
	273	}
	274	late_initcall(msi_bitmap_selftest);
	275	#endif /* CONFIG_MSI_BITMAP_SELFTEST */