forked from Minki/linux
95a2562590
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>
173 lines
4.2 KiB
C
173 lines
4.2 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/acpi_iort.h>
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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 of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev,
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u32 *dev_id)
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{
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int ret, index = 0;
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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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index++;
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} while (!ret);
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return ret;
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}
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int __weak iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
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{
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return -1;
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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;
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msi_info = msi_get_domain_info(domain->parent);
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if (dev->of_node)
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ret = of_pmsi_get_dev_id(domain, dev, &dev_id);
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else
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ret = iort_pmsi_get_dev_id(dev, &dev_id);
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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 const 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_one(struct fwnode_handle *fwnode,
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const char *name)
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{
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struct irq_domain *parent;
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parent = irq_find_matching_fwnode(fwnode, 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", name);
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return -ENXIO;
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}
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if (!platform_msi_create_irq_domain(fwnode, &its_pmsi_domain_info,
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parent)) {
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pr_err("%s: unable to create platform domain\n", name);
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return -ENXIO;
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}
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pr_info("Platform MSI: %s domain created\n", name);
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return 0;
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}
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#ifdef CONFIG_ACPI
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static int __init
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its_pmsi_parse_madt(struct acpi_subtable_header *header,
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const unsigned long end)
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{
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struct acpi_madt_generic_translator *its_entry;
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struct fwnode_handle *domain_handle;
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const char *node_name;
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int err = -ENXIO;
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its_entry = (struct acpi_madt_generic_translator *)header;
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node_name = kasprintf(GFP_KERNEL, "ITS@0x%lx",
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(long)its_entry->base_address);
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domain_handle = iort_find_domain_token(its_entry->translation_id);
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if (!domain_handle) {
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pr_err("%s: Unable to locate ITS domain handle\n", node_name);
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goto out;
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}
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err = its_pmsi_init_one(domain_handle, node_name);
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out:
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kfree(node_name);
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return err;
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}
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static void __init its_pmsi_acpi_init(void)
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{
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acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
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its_pmsi_parse_madt, 0);
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}
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#else
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static inline void its_pmsi_acpi_init(void) { }
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#endif
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static void __init its_pmsi_of_init(void)
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{
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struct device_node *np;
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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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its_pmsi_init_one(of_node_to_fwnode(np), np->full_name);
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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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its_pmsi_of_init();
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its_pmsi_acpi_init();
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return 0;
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}
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early_initcall(its_pmsi_init);
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