kernel-fxtec-pro1x/drivers/irqchip/irq-gic-v3-its-pci-msi.c

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/*
* 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(dev_alias->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(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);