[linux-2.6-block.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/kmemleak.h>
#include <linux/bitmap.h>
#include <linux/memblock.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 %pOF\n", bmp->of_node);
		return 1;
	}

	if (len % (2 * sizeof(u32)) != 0) {
		printk(KERN_WARNING "msi_bitmap: Malformed msi-available-ranges"
		       " property on %pOF\n", bmp->of_node);
		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 __ref 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_alloc(size, SMP_CACHE_BYTES);
		if (!bmp->bitmap)
			panic("%s: Failed to allocate %u bytes\n", __func__,
			      size);
		/* 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;
#define SIZE_EXPECTED 256
	DECLARE_BITMAP(expected, SIZE_EXPECTED);

	/* 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_EXPECTED, &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_EXPECTED,
					get_count_order(SIZE_EXPECTED)));
	bitmap_release_region(bmp.bitmap, 0, get_count_order(SIZE_EXPECTED));

	/* 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_EXPECTED));
	WARN_ON(!bitmap_equal(expected, bmp.bitmap, SIZE_EXPECTED));

	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	12	#include <linux/kernel.h>
514c6032	13	#include <linux/kmemleak.h>
7e302869	14	#include <linux/bitmap.h>
57c8a661	15	#include <linux/memblock.h>
7e302869	16	#include <asm/msi_bitmap.h>
ae3a197e	17	#include <asm/setup.h>
7e302869 ME	18
	19	int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num)
	20	{
	21	unsigned long flags;
	22	int offset, order = get_count_order(num);
	23
	24	spin_lock_irqsave(&bmp->lock, flags);
b0345bbc IM	25
	26	offset = bitmap_find_next_zero_area(bmp->bitmap, bmp->irq_count, 0,
	27	num, (1 << order) - 1);
	28	if (offset > bmp->irq_count)
	29	goto err;
	30
	31	bitmap_set(bmp->bitmap, offset, num);
7e302869 ME	32	spin_unlock_irqrestore(&bmp->lock, flags);
7e302869 ME	33
b0345bbc	34	pr_debug("msi_bitmap: allocated 0x%x at offset 0x%x\n", num, offset);
7e302869 ME	35
7e302869 ME	36	return offset;
b0345bbc IM	37	err:
	38	spin_unlock_irqrestore(&bmp->lock, flags);
	39	return -ENOMEM;
7e302869	40	}
b0345bbc	41	EXPORT_SYMBOL(msi_bitmap_alloc_hwirqs);
7e302869 ME	42
	43	void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset,
	44	unsigned int num)
	45	{
	46	unsigned long flags;
7e302869	47
b0345bbc IM	48	pr_debug("msi_bitmap: freeing 0x%x at offset 0x%x\n",
b0345bbc IM	49	num, offset);
7e302869 ME	50
7e302869 ME	51	spin_lock_irqsave(&bmp->lock, flags);
b0345bbc	52	bitmap_clear(bmp->bitmap, offset, num);
7e302869 ME	53	spin_unlock_irqrestore(&bmp->lock, flags);
7e302869 ME	54	}
b0345bbc	55	EXPORT_SYMBOL(msi_bitmap_free_hwirqs);
7e302869 ME	56
	57	void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq)
	58	{
	59	unsigned long flags;
	60
	61	pr_debug("msi_bitmap: reserving hwirq 0x%x\n", hwirq);
	62
	63	spin_lock_irqsave(&bmp->lock, flags);
	64	bitmap_allocate_region(bmp->bitmap, hwirq, 0);
	65	spin_unlock_irqrestore(&bmp->lock, flags);
	66	}
	67
	68	/**
	69	* msi_bitmap_reserve_dt_hwirqs - Reserve irqs specified in the device tree.
	70	* @bmp: pointer to the MSI bitmap.
	71	*
	72	* Looks in the device tree to see if there is a property specifying which
	73	* irqs can be used for MSI. If found those irqs reserved in the device tree
	74	* are reserved in the bitmap.
	75	*
	76	* Returns 0 for success, < 0 if there was an error, and > 0 if no property
	77	* was found in the device tree.
	78	**/
	79	int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp)
	80	{
	81	int i, j, len;
	82	const u32 *p;
	83
	84	if (!bmp->of_node)
	85	return 1;
	86
	87	p = of_get_property(bmp->of_node, "msi-available-ranges", &len);
	88	if (!p) {
	89	pr_debug("msi_bitmap: no msi-available-ranges property " \
b7c670d6	90	"found on %pOF\n", bmp->of_node);
7e302869 ME	91	return 1;
	92	}
	93
	94	if (len % (2 * sizeof(u32)) != 0) {
	95	printk(KERN_WARNING "msi_bitmap: Malformed msi-available-ranges"
b7c670d6	96	" property on %pOF\n", bmp->of_node);
7e302869 ME	97	return -EINVAL;
	98	}
	99
	100	bitmap_allocate_region(bmp->bitmap, 0, get_count_order(bmp->irq_count));
	101
	102	spin_lock(&bmp->lock);
	103
	104	/* Format is: (<u32 start> <u32 count>)+ */
	105	len /= 2 * sizeof(u32);
	106	for (i = 0; i < len; i++, p += 2) {
	107	for (j = 0; j < *(p + 1); j++)
	108	bitmap_release_region(bmp->bitmap, *p + j, 0);
	109	}
	110
	111	spin_unlock(&bmp->lock);
	112
	113	return 0;
	114	}
	115
bd721ea7	116	int __ref msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count,
7e302869 ME	117	struct device_node *of_node)
	118	{
	119	int size;
	120
	121	if (!irq_count)
	122	return -EINVAL;
	123
	124	size = BITS_TO_LONGS(irq_count) * sizeof(long);
	125	pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size);
	126
cb2d3883 DK	127	bmp->bitmap_from_slab = slab_is_available();
	128	if (bmp->bitmap_from_slab)
	129	bmp->bitmap = kzalloc(size, GFP_KERNEL);
	130	else {
7e1c4e27	131	bmp->bitmap = memblock_alloc(size, SMP_CACHE_BYTES);
8a7f97b9 MR	132	if (!bmp->bitmap)
	133	panic("%s: Failed to allocate %u bytes\n", __func__,
	134	size);
cb2d3883 DK	135	/* the bitmap won't be freed from memblock allocator */
	136	kmemleak_not_leak(bmp->bitmap);
	137	}
	138
7e302869 ME	139	if (!bmp->bitmap) {
	140	pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n");
	141	return -ENOMEM;
	142	}
	143
	144	/* We zalloc'ed the bitmap, so all irqs are free by default */
	145	spin_lock_init(&bmp->lock);
	146	bmp->of_node = of_node_get(of_node);
	147	bmp->irq_count = irq_count;
	148
	149	return 0;
	150	}
	151
	152	void msi_bitmap_free(struct msi_bitmap *bmp)
	153	{
cb2d3883 DK	154	if (bmp->bitmap_from_slab)
cb2d3883 DK	155	kfree(bmp->bitmap);
7e302869 ME	156	of_node_put(bmp->of_node);
	157	bmp->bitmap = NULL;
	158	}
	159
	160	#ifdef CONFIG_MSI_BITMAP_SELFTEST
	161
e51df2c1	162	static void __init test_basics(void)
7e302869 ME	163	{
7e302869 ME	164	struct msi_bitmap bmp;
695911fb	165	int rc, i, size = 512;
7e302869 ME	166
7e302869 ME	167	/* Can't allocate a bitmap of 0 irqs */
4a77f2bd	168	WARN_ON(msi_bitmap_alloc(&bmp, 0, NULL) == 0);
7e302869 ME	169
7e302869 ME	170	/* of_node may be NULL */
4a77f2bd	171	WARN_ON(msi_bitmap_alloc(&bmp, size, NULL));
7e302869 ME	172
7e302869 ME	173	/* Should all be free by default */
4a77f2bd	174	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
7e302869 ME	175	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
	176
	177	/* With no node, there's no msi-available-ranges, so expect > 0 */
4a77f2bd	178	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);
7e302869 ME	179
7e302869 ME	180	/* Should all still be free */
4a77f2bd	181	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
7e302869 ME	182	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
	183
	184	/* Check we can fill it up and then no more */
	185	for (i = 0; i < size; i++)
4a77f2bd	186	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0);
7e302869	187
4a77f2bd	188	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0);
7e302869 ME	189
7e302869 ME	190	/* Should all be allocated */
4a77f2bd	191	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, 0) >= 0);
7e302869 ME	192
	193	/* And if we free one we can then allocate another */
	194	msi_bitmap_free_hwirqs(&bmp, size / 2, 1);
4a77f2bd	195	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) != size / 2);
7e302869	196
695911fb ME	197	/* Free most of them for the alignment tests */
	198	msi_bitmap_free_hwirqs(&bmp, 3, size - 3);
	199
b0345bbc	200	/* Check we get a naturally aligned offset */
695911fb	201	rc = msi_bitmap_alloc_hwirqs(&bmp, 2);
4a77f2bd	202	WARN_ON(rc < 0 && rc % 2 != 0);
695911fb	203	rc = msi_bitmap_alloc_hwirqs(&bmp, 4);
4a77f2bd	204	WARN_ON(rc < 0 && rc % 4 != 0);
695911fb	205	rc = msi_bitmap_alloc_hwirqs(&bmp, 8);
4a77f2bd	206	WARN_ON(rc < 0 && rc % 8 != 0);
695911fb	207	rc = msi_bitmap_alloc_hwirqs(&bmp, 9);
4a77f2bd	208	WARN_ON(rc < 0 && rc % 16 != 0);
695911fb	209	rc = msi_bitmap_alloc_hwirqs(&bmp, 3);
4a77f2bd	210	WARN_ON(rc < 0 && rc % 4 != 0);
695911fb	211	rc = msi_bitmap_alloc_hwirqs(&bmp, 7);
4a77f2bd	212	WARN_ON(rc < 0 && rc % 8 != 0);
695911fb	213	rc = msi_bitmap_alloc_hwirqs(&bmp, 121);
4a77f2bd	214	WARN_ON(rc < 0 && rc % 128 != 0);
b0345bbc	215
7e302869 ME	216	msi_bitmap_free(&bmp);
7e302869 ME	217
4a77f2bd ME	218	/* Clients may WARN_ON bitmap == NULL for "not-allocated" */
4a77f2bd ME	219	WARN_ON(bmp.bitmap != NULL);
7e302869 ME	220	}
7e302869 ME	221
e51df2c1	222	static void __init test_of_node(void)
7e302869 ME	223	{
	224	u32 prop_data[] = { 10, 10, 25, 3, 40, 1, 100, 100, 200, 20 };
	225	const char *expected_str = "0-9,20-24,28-39,41-99,220-255";
	226	char *prop_name = "msi-available-ranges";
	227	char *node_name = "/fakenode";
	228	struct device_node of_node;
	229	struct property prop;
	230	struct msi_bitmap bmp;
1b80ac64 KC	231	#define SIZE_EXPECTED 256
1b80ac64 KC	232	DECLARE_BITMAP(expected, SIZE_EXPECTED);
7e302869 ME	233
	234	/* There should really be a struct device_node allocator */
	235	memset(&of_node, 0, sizeof(of_node));
e47ff70a	236	of_node_init(&of_node);
7e302869 ME	237	of_node.full_name = node_name;
7e302869 ME	238
1b80ac64	239	WARN_ON(msi_bitmap_alloc(&bmp, SIZE_EXPECTED, &of_node));
7e302869 ME	240
7e302869 ME	241	/* No msi-available-ranges, so expect > 0 */
4a77f2bd	242	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);
7e302869 ME	243
7e302869 ME	244	/* Should all still be free */
1b80ac64 KC	245	WARN_ON(bitmap_find_free_region(bmp.bitmap, SIZE_EXPECTED,
	246	get_count_order(SIZE_EXPECTED)));
	247	bitmap_release_region(bmp.bitmap, 0, get_count_order(SIZE_EXPECTED));
7e302869 ME	248
	249	/* Now create a fake msi-available-ranges property */
	250
	251	/* There should really .. oh whatever */
	252	memset(&prop, 0, sizeof(prop));
	253	prop.name = prop_name;
	254	prop.value = &prop_data;
	255	prop.length = sizeof(prop_data);
	256
	257	of_node.properties = &prop;
	258
	259	/* msi-available-ranges, so expect == 0 */
4a77f2bd	260	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp));
7e302869 ME	261
7e302869 ME	262	/* Check we got the expected result */
1b80ac64 KC	263	WARN_ON(bitmap_parselist(expected_str, expected, SIZE_EXPECTED));
1b80ac64 KC	264	WARN_ON(!bitmap_equal(expected, bmp.bitmap, SIZE_EXPECTED));
7e302869 ME	265
	266	msi_bitmap_free(&bmp);
	267	kfree(bmp.bitmap);
	268	}
	269
e51df2c1	270	static int __init msi_bitmap_selftest(void)
7e302869 ME	271	{
	272	printk(KERN_DEBUG "Running MSI bitmap self-tests ...\n");
	273
	274	test_basics();
	275	test_of_node();
	276
	277	return 0;
	278	}
	279	late_initcall(msi_bitmap_selftest);
	280	#endif /* CONFIG_MSI_BITMAP_SELFTEST */