linux/drivers/irqchip/irq-gic-v3-its-pci-msi.c
Stephen Boyd 95a2562590 irqchip/gic-v3: Ignore disabled ITS nodes
On some platforms there's an ITS available but it's not enabled
because reading or writing the registers is denied by the
firmware. In fact, reading or writing them will cause the system
to reset. We could remove the node from DT in such a case, but
it's better to skip nodes that are marked as "disabled" in DT so
that we can describe the hardware that exists and use the status
property to indicate how the firmware has configured things.

Cc: Stuart Yoder <stuyoder@gmail.com>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-02-16 13:47:58 +00:00

199 lines
4.9 KiB
C

/*
* 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/acpi_iort.h>
#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,
};
static int its_pci_msi_vec_count(struct pci_dev *pdev, void *data)
{
int msi, msix, *count = data;
msi = max(pci_msi_vec_count(pdev), 0);
msix = max(pci_msix_vec_count(pdev), 0);
*count += max(msi, msix);
return 0;
}
static int its_get_pci_alias(struct pci_dev *pdev, u16 alias, void *data)
{
struct pci_dev **alias_dev = data;
*alias_dev = 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, *alias_dev;
struct msi_domain_info *msi_info;
int alias_count = 0;
if (!dev_is_pci(dev))
return -EINVAL;
msi_info = msi_get_domain_info(domain->parent);
pdev = to_pci_dev(dev);
/*
* If pdev is downstream of any aliasing bridges, take an upper
* bound of how many other vectors could map to the same DevID.
*/
pci_for_each_dma_alias(pdev, its_get_pci_alias, &alias_dev);
if (alias_dev != pdev && alias_dev->subordinate)
pci_walk_bus(alias_dev->subordinate, its_pci_msi_vec_count,
&alias_count);
/* ITS specific DeviceID, as the core ITS ignores dev. */
info->scratchpad[0].ul = pci_msi_domain_get_msi_rid(domain, pdev);
return msi_info->ops->msi_prepare(domain->parent,
dev, max(nvec, 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_one(struct fwnode_handle *handle,
const char *name)
{
struct irq_domain *parent;
parent = irq_find_matching_fwnode(handle, DOMAIN_BUS_NEXUS);
if (!parent || !msi_get_domain_info(parent)) {
pr_err("%s: Unable to locate ITS domain\n", name);
return -ENXIO;
}
if (!pci_msi_create_irq_domain(handle, &its_pci_msi_domain_info,
parent)) {
pr_err("%s: Unable to create PCI domain\n", name);
return -ENOMEM;
}
return 0;
}
static int __init its_pci_of_msi_init(void)
{
struct device_node *np;
for (np = of_find_matching_node(NULL, its_device_id); np;
np = of_find_matching_node(np, its_device_id)) {
if (!of_device_is_available(np))
continue;
if (!of_property_read_bool(np, "msi-controller"))
continue;
if (its_pci_msi_init_one(of_node_to_fwnode(np), np->full_name))
continue;
pr_info("PCI/MSI: %pOF domain created\n", np);
}
return 0;
}
#ifdef CONFIG_ACPI
static int __init
its_pci_msi_parse_madt(struct acpi_subtable_header *header,
const unsigned long end)
{
struct acpi_madt_generic_translator *its_entry;
struct fwnode_handle *dom_handle;
const char *node_name;
int err = -ENXIO;
its_entry = (struct acpi_madt_generic_translator *)header;
node_name = kasprintf(GFP_KERNEL, "ITS@0x%lx",
(long)its_entry->base_address);
dom_handle = iort_find_domain_token(its_entry->translation_id);
if (!dom_handle) {
pr_err("%s: Unable to locate ITS domain handle\n", node_name);
goto out;
}
err = its_pci_msi_init_one(dom_handle, node_name);
if (!err)
pr_info("PCI/MSI: %s domain created\n", node_name);
out:
kfree(node_name);
return err;
}
static int __init its_pci_acpi_msi_init(void)
{
acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
its_pci_msi_parse_madt, 0);
return 0;
}
#else
static int __init its_pci_acpi_msi_init(void)
{
return 0;
}
#endif
static int __init its_pci_msi_init(void)
{
its_pci_of_msi_init();
its_pci_acpi_msi_init();
return 0;
}
early_initcall(its_pci_msi_init);