summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/sysdev/mpic_u3msi.c
blob: 1d5a40899b74fac796ac814aad3d1a1c2c805a89 (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
/*
 * Copyright 2006, Segher Boessenkool, IBM Corporation.
 * 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/bootmem.h>
#include <linux/msi.h>
#include <asm/mpic.h>
#include <asm/prom.h>
#include <asm/hw_irq.h>
#include <asm/ppc-pci.h>

#include "mpic.h"

/* A bit ugly, can we get this from the pci_dev somehow? */
static struct mpic *msi_mpic;

static void mpic_u3msi_mask_irq(unsigned int irq)
{
	mask_msi_irq(irq);
	mpic_mask_irq(irq);
}

static void mpic_u3msi_unmask_irq(unsigned int irq)
{
	mpic_unmask_irq(irq);
	unmask_msi_irq(irq);
}

static struct irq_chip mpic_u3msi_chip = {
	.shutdown	= mpic_u3msi_mask_irq,
	.mask		= mpic_u3msi_mask_irq,
	.unmask		= mpic_u3msi_unmask_irq,
	.eoi		= mpic_end_irq,
	.set_type	= mpic_set_irq_type,
	.set_affinity	= mpic_set_affinity,
	.typename	= "MPIC-U3MSI",
};

static u64 read_ht_magic_addr(struct pci_dev *pdev, unsigned int pos)
{
	u8 flags;
	u32 tmp;
	u64 addr;

	pci_read_config_byte(pdev, pos + HT_MSI_FLAGS, &flags);

	if (flags & HT_MSI_FLAGS_FIXED)
		return HT_MSI_FIXED_ADDR;

	pci_read_config_dword(pdev, pos + HT_MSI_ADDR_LO, &tmp);
	addr = tmp & HT_MSI_ADDR_LO_MASK;
	pci_read_config_dword(pdev, pos + HT_MSI_ADDR_HI, &tmp);
	addr = addr | ((u64)tmp << 32);

	return addr;
}

static u64 find_ht_magic_addr(struct pci_dev *pdev)
{
	struct pci_bus *bus;
	unsigned int pos;

	for (bus = pdev->bus; bus; bus = bus->parent) {
		pos = pci_find_ht_capability(bus->self, HT_CAPTYPE_MSI_MAPPING);
		if (pos)
			return read_ht_magic_addr(bus->self, pos);
	}

	return 0;
}

static int u3msi_msi_check_device(struct pci_dev *pdev, int nvec, int type)
{
	if (type == PCI_CAP_ID_MSIX)
		pr_debug("u3msi: MSI-X untested, trying anyway.\n");

	/* If we can't find a magic address then MSI ain't gonna work */
	if (find_ht_magic_addr(pdev) == 0) {
		pr_debug("u3msi: no magic address found for %s\n",
			 pci_name(pdev));
		return -ENXIO;
	}

	return 0;
}

static void u3msi_teardown_msi_irqs(struct pci_dev *pdev)
{
	struct msi_desc *entry;

        list_for_each_entry(entry, &pdev->msi_list, list) {
		if (entry->irq == NO_IRQ)
			continue;

		set_irq_msi(entry->irq, NULL);
		mpic_msi_free_hwirqs(msi_mpic, virq_to_hw(entry->irq), 1);
		irq_dispose_mapping(entry->irq);
	}

	return;
}

static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
{
	irq_hw_number_t hwirq;
	unsigned int virq;
	struct msi_desc *entry;
	struct msi_msg msg;
	u64 addr;

	addr = find_ht_magic_addr(pdev);
	msg.address_lo = addr & 0xFFFFFFFF;
	msg.address_hi = addr >> 32;

	list_for_each_entry(entry, &pdev->msi_list, list) {
		hwirq = mpic_msi_alloc_hwirqs(msi_mpic, 1);
		if (hwirq < 0) {
			pr_debug("u3msi: failed allocating hwirq\n");
			return hwirq;
		}

		virq = irq_create_mapping(msi_mpic->irqhost, hwirq);
		if (virq == NO_IRQ) {
			pr_debug("u3msi: failed mapping hwirq 0x%lx\n", hwirq);
			mpic_msi_free_hwirqs(msi_mpic, hwirq, 1);
			return -ENOSPC;
		}

		set_irq_msi(virq, entry);
		set_irq_chip(virq, &mpic_u3msi_chip);
		set_irq_type(virq, IRQ_TYPE_EDGE_RISING);

		pr_debug("u3msi: allocated virq 0x%x (hw 0x%lx) addr 0x%lx\n",
			  virq, hwirq, addr);

		msg.data = hwirq;
		write_msi_msg(virq, &msg);

		hwirq++;
	}

	return 0;
}

int mpic_u3msi_init(struct mpic *mpic)
{
	int rc;

	rc = mpic_msi_init_allocator(mpic);
	if (rc) {
		pr_debug("u3msi: Error allocating bitmap!\n");
		return rc;
	}

	pr_debug("u3msi: Registering MPIC U3 MSI callbacks.\n");

	BUG_ON(msi_mpic);
	msi_mpic = mpic;

	WARN_ON(ppc_md.setup_msi_irqs);
	ppc_md.setup_msi_irqs = u3msi_setup_msi_irqs;
	ppc_md.teardown_msi_irqs = u3msi_teardown_msi_irqs;
	ppc_md.msi_check_device = u3msi_msi_check_device;

	return 0;
}