[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 <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 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 = zalloc_maybe_bootmem(size, GFP_KERNEL);
	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)
{
	/* we can't free the bitmap we don't know if it's bootmem etc. */
	of_node_put(bmp->of_node);
	bmp->bitmap = NULL;
}

#ifdef CONFIG_MSI_BITMAP_SELFTEST

#define check(x)	\
	if (!(x)) printk("msi_bitmap: test failed at line %d\n", __LINE__);

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

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

	/* of_node may be NULL */
	check(0 == msi_bitmap_alloc(&bmp, size, NULL));

	/* Should all be free by default */
	check(0 == 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 */
	check(msi_bitmap_reserve_dt_hwirqs(&bmp) > 0);

	/* Should all still be free */
	check(0 == 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++)
		check(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0);

	check(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0);

	/* Should all be allocated */
	check(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);
	check(msi_bitmap_alloc_hwirqs(&bmp, 1) == size / 2);

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

	msi_bitmap_free(&bmp);

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

	kfree(bmp.bitmap);
}

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;

	check(0 == msi_bitmap_alloc(&bmp, size, &of_node));

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

	/* Should all still be free */
	check(0 == 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 */
	check(msi_bitmap_reserve_dt_hwirqs(&bmp) == 0);

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