7f409f1576
[ Upstream commit 95a2562590c2f64a0398183f978d5cf3db6d0284 ] 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> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
108 lines
2.8 KiB
C
108 lines
2.8 KiB
C
/*
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* Copyright (C) 2013-2015 ARM Limited, All Rights Reserved.
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* Author: Marc Zyngier <marc.zyngier@arm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/device.h>
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#include <linux/msi.h>
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#include <linux/of.h>
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#include <linux/of_irq.h>
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static struct irq_chip its_pmsi_irq_chip = {
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.name = "ITS-pMSI",
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};
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static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
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int nvec, msi_alloc_info_t *info)
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{
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struct msi_domain_info *msi_info;
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u32 dev_id;
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int ret, index = 0;
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msi_info = msi_get_domain_info(domain->parent);
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/* Suck the DeviceID out of the msi-parent property */
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do {
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struct of_phandle_args args;
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ret = of_parse_phandle_with_args(dev->of_node,
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"msi-parent", "#msi-cells",
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index, &args);
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if (args.np == irq_domain_get_of_node(domain)) {
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if (WARN_ON(args.args_count != 1))
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return -EINVAL;
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dev_id = args.args[0];
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break;
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}
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} while (!ret);
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if (ret)
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return ret;
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/* ITS specific DeviceID, as the core ITS ignores dev. */
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info->scratchpad[0].ul = dev_id;
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return msi_info->ops->msi_prepare(domain->parent,
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dev, nvec, info);
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}
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static struct msi_domain_ops its_pmsi_ops = {
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.msi_prepare = its_pmsi_prepare,
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};
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static struct msi_domain_info its_pmsi_domain_info = {
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.flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
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.ops = &its_pmsi_ops,
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.chip = &its_pmsi_irq_chip,
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};
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static struct of_device_id its_device_id[] = {
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{ .compatible = "arm,gic-v3-its", },
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{},
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};
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static int __init its_pmsi_init(void)
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{
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struct device_node *np;
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struct irq_domain *parent;
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for (np = of_find_matching_node(NULL, its_device_id); np;
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np = of_find_matching_node(np, its_device_id)) {
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if (!of_device_is_available(np))
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continue;
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if (!of_property_read_bool(np, "msi-controller"))
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continue;
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parent = irq_find_matching_host(np, DOMAIN_BUS_NEXUS);
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if (!parent || !msi_get_domain_info(parent)) {
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pr_err("%s: unable to locate ITS domain\n",
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np->full_name);
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continue;
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}
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if (!platform_msi_create_irq_domain(of_node_to_fwnode(np),
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&its_pmsi_domain_info,
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parent)) {
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pr_err("%s: unable to create platform domain\n",
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np->full_name);
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continue;
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}
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pr_info("Platform MSI: %s domain created\n", np->full_name);
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}
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return 0;
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}
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early_initcall(its_pmsi_init);
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