summaryrefslogtreecommitdiff
path: root/arch/powerpc/sysdev/mpic_msi.c
blob: d272a52ecd24ace9af35e8f3758e60165fed9c49 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/*
 * Copyright 2006-2007, 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/irq.h>
#include <linux/bitmap.h>
#include <linux/msi.h>
#include <asm/mpic.h>
#include <asm/prom.h>
#include <asm/hw_irq.h>
#include <asm/ppc-pci.h>


static void __mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq)
{
	pr_debug("mpic: reserving hwirq 0x%lx\n", hwirq);
	bitmap_allocate_region(mpic->hwirq_bitmap, hwirq, 0);
}

void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq)
{
	unsigned long flags;

	/* The mpic calls this even when there is no allocator setup */
	if (!mpic->hwirq_bitmap)
		return;

	spin_lock_irqsave(&mpic->bitmap_lock, flags);
	__mpic_msi_reserve_hwirq(mpic, hwirq);
	spin_unlock_irqrestore(&mpic->bitmap_lock, flags);
}

irq_hw_number_t mpic_msi_alloc_hwirqs(struct mpic *mpic, int num)
{
	unsigned long flags;
	int offset, order = get_count_order(num);

	spin_lock_irqsave(&mpic->bitmap_lock, flags);
	/*
	 * This is fast, but stricter than we need. We might want to add
	 * a fallback routine which does a linear search with no alignment.
	 */
	offset = bitmap_find_free_region(mpic->hwirq_bitmap, mpic->irq_count,
					 order);
	spin_unlock_irqrestore(&mpic->bitmap_lock, flags);

	pr_debug("mpic: allocated 0x%x (2^%d) at offset 0x%x\n",
		 num, order, offset);

	return offset;
}

void mpic_msi_free_hwirqs(struct mpic *mpic, int offset, int num)
{
	unsigned long flags;
	int order = get_count_order(num);

	pr_debug("mpic: freeing 0x%x (2^%d) at offset 0x%x\n",
		 num, order, offset);

	spin_lock_irqsave(&mpic->bitmap_lock, flags);
	bitmap_release_region(mpic->hwirq_bitmap, offset, order);
	spin_unlock_irqrestore(&mpic->bitmap_lock, flags);
}

#ifdef CONFIG_MPIC_U3_HT_IRQS
static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
{
	irq_hw_number_t hwirq;
	struct irq_host_ops *ops = mpic->irqhost->ops;
	struct device_node *np;
	int flags, index, i;
	struct of_irq oirq;

	pr_debug("mpic: found U3, guessing msi allocator setup\n");

	/* Reserve source numbers we know are reserved in the HW */
	for (i = 0;   i < 8;   i++)
		__mpic_msi_reserve_hwirq(mpic, i);

	for (i = 42;  i < 46;  i++)
		__mpic_msi_reserve_hwirq(mpic, i);

	for (i = 100; i < 105; i++)
		__mpic_msi_reserve_hwirq(mpic, i);

	np = NULL;
	while ((np = of_find_all_nodes(np))) {
		pr_debug("mpic: mapping hwirqs for %s\n", np->full_name);

		index = 0;
		while (of_irq_map_one(np, index++, &oirq) == 0) {
			ops->xlate(mpic->irqhost, NULL, oirq.specifier,
						oirq.size, &hwirq, &flags);
			__mpic_msi_reserve_hwirq(mpic, hwirq);
		}
	}

	return 0;
}
#else
static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
{
	return -1;
}
#endif

static int mpic_msi_reserve_dt_hwirqs(struct mpic *mpic)
{
	int i, len;
	const u32 *p;

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

	if (len % 8 != 0) {
		printk(KERN_WARNING "mpic: Malformed msi-available-ranges "
		       "property on %s\n", mpic->irqhost->of_node->full_name);
		return -EINVAL;
	}

	bitmap_allocate_region(mpic->hwirq_bitmap, 0,
			       get_count_order(mpic->irq_count));

	/* Format is: (<u32 start> <u32 count>)+ */
	len /= sizeof(u32);
	for (i = 0; i < len / 2; i++, p += 2)
		mpic_msi_free_hwirqs(mpic, *p, *(p + 1));

	return 0;
}

int mpic_msi_init_allocator(struct mpic *mpic)
{
	int rc, size;

	BUG_ON(mpic->hwirq_bitmap);
	spin_lock_init(&mpic->bitmap_lock);

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

	mpic->hwirq_bitmap = alloc_maybe_bootmem(size, GFP_KERNEL);

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

	memset(mpic->hwirq_bitmap, 0, size);

	rc = mpic_msi_reserve_dt_hwirqs(mpic);
	if (rc) {
		if (mpic->flags & MPIC_U3_HT_IRQS)
			rc = mpic_msi_reserve_u3_hwirqs(mpic);

		if (rc)
			goto out_free;
	}

	return 0;

 out_free:
	if (mem_init_done)
		kfree(mpic->hwirq_bitmap);

	mpic->hwirq_bitmap = NULL;
	return rc;
}