[linux-2.6-block.git] / arch / powerpc / sysdev / msi_bitmap.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2006-2008, Michael Ellerman, IBM Corporation.
 */

#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
b886d83c	1	// SPDX-License-Identifier: GPL-2.0-only
7e302869 ME	2	/*
7e302869 ME	3	* Copyright 2006-2008, Michael Ellerman, IBM Corporation.
7e302869 ME	4	*/
7e302869 ME	5
5a0e3ad6	6	#include <linux/slab.h>
7e302869	7	#include <linux/kernel.h>
514c6032	8	#include <linux/kmemleak.h>
7e302869	9	#include <linux/bitmap.h>
57c8a661	10	#include <linux/memblock.h>
7e302869	11	#include <asm/msi_bitmap.h>
ae3a197e	12	#include <asm/setup.h>
7e302869 ME	13
	14	int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num)
	15	{
	16	unsigned long flags;
	17	int offset, order = get_count_order(num);
	18
	19	spin_lock_irqsave(&bmp->lock, flags);
b0345bbc IM	20
	21	offset = bitmap_find_next_zero_area(bmp->bitmap, bmp->irq_count, 0,
	22	num, (1 << order) - 1);
	23	if (offset > bmp->irq_count)
	24	goto err;
	25
	26	bitmap_set(bmp->bitmap, offset, num);
7e302869 ME	27	spin_unlock_irqrestore(&bmp->lock, flags);
7e302869 ME	28
b0345bbc	29	pr_debug("msi_bitmap: allocated 0x%x at offset 0x%x\n", num, offset);
7e302869 ME	30
7e302869 ME	31	return offset;
b0345bbc IM	32	err:
	33	spin_unlock_irqrestore(&bmp->lock, flags);
	34	return -ENOMEM;
7e302869	35	}
b0345bbc	36	EXPORT_SYMBOL(msi_bitmap_alloc_hwirqs);
7e302869 ME	37
	38	void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset,
	39	unsigned int num)
	40	{
	41	unsigned long flags;
7e302869	42
b0345bbc IM	43	pr_debug("msi_bitmap: freeing 0x%x at offset 0x%x\n",
b0345bbc IM	44	num, offset);
7e302869 ME	45
7e302869 ME	46	spin_lock_irqsave(&bmp->lock, flags);
b0345bbc	47	bitmap_clear(bmp->bitmap, offset, num);
7e302869 ME	48	spin_unlock_irqrestore(&bmp->lock, flags);
7e302869 ME	49	}
b0345bbc	50	EXPORT_SYMBOL(msi_bitmap_free_hwirqs);
7e302869 ME	51
	52	void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq)
	53	{
	54	unsigned long flags;
	55
	56	pr_debug("msi_bitmap: reserving hwirq 0x%x\n", hwirq);
	57
	58	spin_lock_irqsave(&bmp->lock, flags);
	59	bitmap_allocate_region(bmp->bitmap, hwirq, 0);
	60	spin_unlock_irqrestore(&bmp->lock, flags);
	61	}
	62
	63	/**
	64	* msi_bitmap_reserve_dt_hwirqs - Reserve irqs specified in the device tree.
	65	* @bmp: pointer to the MSI bitmap.
	66	*
	67	* Looks in the device tree to see if there is a property specifying which
	68	* irqs can be used for MSI. If found those irqs reserved in the device tree
	69	* are reserved in the bitmap.
	70	*
	71	* Returns 0 for success, < 0 if there was an error, and > 0 if no property
	72	* was found in the device tree.
	73	**/
	74	int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp)
	75	{
	76	int i, j, len;
	77	const u32 *p;
	78
	79	if (!bmp->of_node)
	80	return 1;
	81
	82	p = of_get_property(bmp->of_node, "msi-available-ranges", &len);
	83	if (!p) {
	84	pr_debug("msi_bitmap: no msi-available-ranges property " \
b7c670d6	85	"found on %pOF\n", bmp->of_node);
7e302869 ME	86	return 1;
	87	}
	88
	89	if (len % (2 * sizeof(u32)) != 0) {
	90	printk(KERN_WARNING "msi_bitmap: Malformed msi-available-ranges"
b7c670d6	91	" property on %pOF\n", bmp->of_node);
7e302869 ME	92	return -EINVAL;
	93	}
	94
	95	bitmap_allocate_region(bmp->bitmap, 0, get_count_order(bmp->irq_count));
	96
	97	spin_lock(&bmp->lock);
	98
	99	/* Format is: (<u32 start> <u32 count>)+ */
	100	len /= 2 * sizeof(u32);
	101	for (i = 0; i < len; i++, p += 2) {
	102	for (j = 0; j < *(p + 1); j++)
	103	bitmap_release_region(bmp->bitmap, *p + j, 0);
	104	}
	105
	106	spin_unlock(&bmp->lock);
	107
	108	return 0;
	109	}
	110
bd721ea7	111	int __ref msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count,
7e302869 ME	112	struct device_node *of_node)
	113	{
	114	int size;
	115
	116	if (!irq_count)
	117	return -EINVAL;
	118
	119	size = BITS_TO_LONGS(irq_count) * sizeof(long);
	120	pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size);
	121
cb2d3883 DK	122	bmp->bitmap_from_slab = slab_is_available();
	123	if (bmp->bitmap_from_slab)
	124	bmp->bitmap = kzalloc(size, GFP_KERNEL);
	125	else {
7e1c4e27	126	bmp->bitmap = memblock_alloc(size, SMP_CACHE_BYTES);
8a7f97b9 MR	127	if (!bmp->bitmap)
	128	panic("%s: Failed to allocate %u bytes\n", __func__,
	129	size);
cb2d3883 DK	130	/* the bitmap won't be freed from memblock allocator */
	131	kmemleak_not_leak(bmp->bitmap);
	132	}
	133
7e302869 ME	134	if (!bmp->bitmap) {
	135	pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n");
	136	return -ENOMEM;
	137	}
	138
	139	/* We zalloc'ed the bitmap, so all irqs are free by default */
	140	spin_lock_init(&bmp->lock);
	141	bmp->of_node = of_node_get(of_node);
	142	bmp->irq_count = irq_count;
	143
	144	return 0;
	145	}
	146
	147	void msi_bitmap_free(struct msi_bitmap *bmp)
	148	{
cb2d3883 DK	149	if (bmp->bitmap_from_slab)
cb2d3883 DK	150	kfree(bmp->bitmap);
7e302869 ME	151	of_node_put(bmp->of_node);
	152	bmp->bitmap = NULL;
	153	}
	154
	155	#ifdef CONFIG_MSI_BITMAP_SELFTEST
	156
e51df2c1	157	static void __init test_basics(void)
7e302869 ME	158	{
7e302869 ME	159	struct msi_bitmap bmp;
695911fb	160	int rc, i, size = 512;
7e302869 ME	161
7e302869 ME	162	/* Can't allocate a bitmap of 0 irqs */
4a77f2bd	163	WARN_ON(msi_bitmap_alloc(&bmp, 0, NULL) == 0);
7e302869 ME	164
7e302869 ME	165	/* of_node may be NULL */
4a77f2bd	166	WARN_ON(msi_bitmap_alloc(&bmp, size, NULL));
7e302869 ME	167
7e302869 ME	168	/* Should all be free by default */
4a77f2bd	169	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
7e302869 ME	170	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
	171
	172	/* With no node, there's no msi-available-ranges, so expect > 0 */
4a77f2bd	173	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);
7e302869 ME	174
7e302869 ME	175	/* Should all still be free */
4a77f2bd	176	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
7e302869 ME	177	bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
	178
	179	/* Check we can fill it up and then no more */
	180	for (i = 0; i < size; i++)
4a77f2bd	181	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0);
7e302869	182
4a77f2bd	183	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0);
7e302869 ME	184
7e302869 ME	185	/* Should all be allocated */
4a77f2bd	186	WARN_ON(bitmap_find_free_region(bmp.bitmap, size, 0) >= 0);
7e302869 ME	187
	188	/* And if we free one we can then allocate another */
	189	msi_bitmap_free_hwirqs(&bmp, size / 2, 1);
4a77f2bd	190	WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) != size / 2);
7e302869	191
695911fb ME	192	/* Free most of them for the alignment tests */
	193	msi_bitmap_free_hwirqs(&bmp, 3, size - 3);
	194
b0345bbc	195	/* Check we get a naturally aligned offset */
695911fb	196	rc = msi_bitmap_alloc_hwirqs(&bmp, 2);
4a77f2bd	197	WARN_ON(rc < 0 && rc % 2 != 0);
695911fb	198	rc = msi_bitmap_alloc_hwirqs(&bmp, 4);
4a77f2bd	199	WARN_ON(rc < 0 && rc % 4 != 0);
695911fb	200	rc = msi_bitmap_alloc_hwirqs(&bmp, 8);
4a77f2bd	201	WARN_ON(rc < 0 && rc % 8 != 0);
695911fb	202	rc = msi_bitmap_alloc_hwirqs(&bmp, 9);
4a77f2bd	203	WARN_ON(rc < 0 && rc % 16 != 0);
695911fb	204	rc = msi_bitmap_alloc_hwirqs(&bmp, 3);
4a77f2bd	205	WARN_ON(rc < 0 && rc % 4 != 0);
695911fb	206	rc = msi_bitmap_alloc_hwirqs(&bmp, 7);
4a77f2bd	207	WARN_ON(rc < 0 && rc % 8 != 0);
695911fb	208	rc = msi_bitmap_alloc_hwirqs(&bmp, 121);
4a77f2bd	209	WARN_ON(rc < 0 && rc % 128 != 0);
b0345bbc	210
7e302869 ME	211	msi_bitmap_free(&bmp);
7e302869 ME	212
4a77f2bd ME	213	/* Clients may WARN_ON bitmap == NULL for "not-allocated" */
4a77f2bd ME	214	WARN_ON(bmp.bitmap != NULL);
7e302869 ME	215	}
7e302869 ME	216
e51df2c1	217	static void __init test_of_node(void)
7e302869 ME	218	{
	219	u32 prop_data[] = { 10, 10, 25, 3, 40, 1, 100, 100, 200, 20 };
	220	const char *expected_str = "0-9,20-24,28-39,41-99,220-255";
	221	char *prop_name = "msi-available-ranges";
	222	char *node_name = "/fakenode";
	223	struct device_node of_node;
	224	struct property prop;
	225	struct msi_bitmap bmp;
1b80ac64 KC	226	#define SIZE_EXPECTED 256
1b80ac64 KC	227	DECLARE_BITMAP(expected, SIZE_EXPECTED);
7e302869 ME	228
	229	/* There should really be a struct device_node allocator */
	230	memset(&of_node, 0, sizeof(of_node));
e47ff70a	231	of_node_init(&of_node);
7e302869 ME	232	of_node.full_name = node_name;
7e302869 ME	233
1b80ac64	234	WARN_ON(msi_bitmap_alloc(&bmp, SIZE_EXPECTED, &of_node));
7e302869 ME	235
7e302869 ME	236	/* No msi-available-ranges, so expect > 0 */
4a77f2bd	237	WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);
7e302869 ME	238
7e302869 ME	239	/* Should all still be free */
1b80ac64 KC	240	WARN_ON(bitmap_find_free_region(bmp.bitmap, SIZE_EXPECTED,
	241	get_count_order(SIZE_EXPECTED)));
	242	bitmap_release_region(bmp.bitmap, 0, get_count_order(SIZE_EXPECTED));
7e302869 ME	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 */
1b80ac64 KC	258	WARN_ON(bitmap_parselist(expected_str, expected, SIZE_EXPECTED));
1b80ac64 KC	259	WARN_ON(!bitmap_equal(expected, bmp.bitmap, SIZE_EXPECTED));
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 */