summaryrefslogtreecommitdiffstats
path: root/drivers/irqchip/irq-gic-v3-its-pci-msi.c
blob: 693c2f9ae898d3635aa3d02b7a6a712722786bc9 (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
/*
 * Copyright (C) 2013-2015 ARM Limited, All Rights Reserved.
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/msi.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_pci.h>

static void its_mask_msi_irq(struct irq_data *d)
{
	pci_msi_mask_irq(d);
	irq_chip_mask_parent(d);
}

static void its_unmask_msi_irq(struct irq_data *d)
{
	pci_msi_unmask_irq(d);
	irq_chip_unmask_parent(d);
}

static struct irq_chip its_msi_irq_chip = {
	.name			= "ITS-MSI",
	.irq_unmask		= its_unmask_msi_irq,
	.irq_mask		= its_mask_msi_irq,
	.irq_eoi		= irq_chip_eoi_parent,
	.irq_write_msi_msg	= pci_msi_domain_write_msg,
};

struct its_pci_alias {
	struct pci_dev	*pdev;
	u32		dev_id;
	u32		count;
};

static int its_pci_msi_vec_count(struct pci_dev *pdev)
{
	int msi, msix;

	msi = max(pci_msi_vec_count(pdev), 0);
	msix = max(pci_msix_vec_count(pdev), 0);

	return max(msi, msix);
}

static int its_get_pci_alias(struct pci_dev *pdev, u16 alias, void *data)
{
	struct its_pci_alias *dev_alias = data;

	dev_alias->dev_id = alias;
	if (pdev != dev_alias->pdev)
		dev_alias->count += its_pci_msi_vec_count(pdev);

	return 0;
}

static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
			       int nvec, msi_alloc_info_t *info)
{
	struct pci_dev *pdev;
	struct its_pci_alias dev_alias;
	struct msi_domain_info *msi_info;

	if (!dev_is_pci(dev))
		return -EINVAL;

	msi_info = msi_get_domain_info(domain->parent);

	pdev = to_pci_dev(dev);
	dev_alias.pdev = pdev;
	dev_alias.count = nvec;

	pci_for_each_dma_alias(pdev, its_get_pci_alias, &dev_alias);

	/* ITS specific DeviceID, as the core ITS ignores dev. */
	info->scratchpad[0].ul = dev_alias.dev_id;

	return msi_info->ops->msi_prepare(domain->parent,
					  dev, dev_alias.count, info);
}

static struct msi_domain_ops its_pci_msi_ops = {
	.msi_prepare	= its_pci_msi_prepare,
};

static struct msi_domain_info its_pci_msi_domain_info = {
	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
		   MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX),
	.ops	= &its_pci_msi_ops,
	.chip	= &its_msi_irq_chip,
};

static struct of_device_id its_device_id[] = {
	{	.compatible	= "arm,gic-v3-its",	},
	{},
};

static int __init its_pci_msi_init(void)
{
	struct device_node *np;
	struct irq_domain *parent;

	for (np = of_find_matching_node(NULL, its_device_id); np;
	     np = of_find_matching_node(np, its_device_id)) {
		if (!of_property_read_bool(np, "msi-controller"))
			continue;

		parent = irq_find_matching_host(np, DOMAIN_BUS_NEXUS);
		if (!parent || !msi_get_domain_info(parent)) {
			pr_err("%s: unable to locate ITS domain\n",
			       np->full_name);
			continue;
		}

		if (!pci_msi_create_irq_domain(of_node_to_fwnode(np),
					       &its_pci_msi_domain_info,
					       parent)) {
			pr_err("%s: unable to create PCI domain\n",
			       np->full_name);
			continue;
		}

		pr_info("PCI/MSI: %s domain created\n", np->full_name);
	}

	return 0;
}
early_initcall(its_pci_msi_init);