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path: root/drivers/irqchip/irq-gic-v3-its-platform-msi.c
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Diffstat (limited to 'drivers/irqchip/irq-gic-v3-its-platform-msi.c')
-rw-r--r--drivers/irqchip/irq-gic-v3-its-platform-msi.c163
1 files changed, 163 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its-platform-msi.c b/drivers/irqchip/irq-gic-v3-its-platform-msi.c
new file mode 100644
index 0000000000..daa6d5053b
--- /dev/null
+++ b/drivers/irqchip/irq-gic-v3-its-platform-msi.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2013-2015 ARM Limited, All Rights Reserved.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#include <linux/acpi_iort.h>
+#include <linux/device.h>
+#include <linux/msi.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+
+static struct irq_chip its_pmsi_irq_chip = {
+ .name = "ITS-pMSI",
+};
+
+static int of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev,
+ u32 *dev_id)
+{
+ int ret, index = 0;
+
+ /* Suck the DeviceID out of the msi-parent property */
+ do {
+ struct of_phandle_args args;
+
+ ret = of_parse_phandle_with_args(dev->of_node,
+ "msi-parent", "#msi-cells",
+ index, &args);
+ if (args.np == irq_domain_get_of_node(domain)) {
+ if (WARN_ON(args.args_count != 1))
+ return -EINVAL;
+ *dev_id = args.args[0];
+ break;
+ }
+ index++;
+ } while (!ret);
+
+ return ret;
+}
+
+int __weak iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
+{
+ return -1;
+}
+
+static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
+ int nvec, msi_alloc_info_t *info)
+{
+ struct msi_domain_info *msi_info;
+ u32 dev_id;
+ int ret;
+
+ msi_info = msi_get_domain_info(domain->parent);
+
+ if (dev->of_node)
+ ret = of_pmsi_get_dev_id(domain, dev, &dev_id);
+ else
+ ret = iort_pmsi_get_dev_id(dev, &dev_id);
+ if (ret)
+ return ret;
+
+ /* ITS specific DeviceID, as the core ITS ignores dev. */
+ info->scratchpad[0].ul = dev_id;
+
+ /* Allocate at least 32 MSIs, and always as a power of 2 */
+ nvec = max_t(int, 32, roundup_pow_of_two(nvec));
+ return msi_info->ops->msi_prepare(domain->parent,
+ dev, nvec, info);
+}
+
+static struct msi_domain_ops its_pmsi_ops = {
+ .msi_prepare = its_pmsi_prepare,
+};
+
+static struct msi_domain_info its_pmsi_domain_info = {
+ .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
+ .ops = &its_pmsi_ops,
+ .chip = &its_pmsi_irq_chip,
+};
+
+static const struct of_device_id its_device_id[] = {
+ { .compatible = "arm,gic-v3-its", },
+ {},
+};
+
+static int __init its_pmsi_init_one(struct fwnode_handle *fwnode,
+ const char *name)
+{
+ struct irq_domain *parent;
+
+ parent = irq_find_matching_fwnode(fwnode, DOMAIN_BUS_NEXUS);
+ if (!parent || !msi_get_domain_info(parent)) {
+ pr_err("%s: unable to locate ITS domain\n", name);
+ return -ENXIO;
+ }
+
+ if (!platform_msi_create_irq_domain(fwnode, &its_pmsi_domain_info,
+ parent)) {
+ pr_err("%s: unable to create platform domain\n", name);
+ return -ENXIO;
+ }
+
+ pr_info("Platform MSI: %s domain created\n", name);
+ return 0;
+}
+
+#ifdef CONFIG_ACPI
+static int __init
+its_pmsi_parse_madt(union acpi_subtable_headers *header,
+ const unsigned long end)
+{
+ struct acpi_madt_generic_translator *its_entry;
+ struct fwnode_handle *domain_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);
+ domain_handle = iort_find_domain_token(its_entry->translation_id);
+ if (!domain_handle) {
+ pr_err("%s: Unable to locate ITS domain handle\n", node_name);
+ goto out;
+ }
+
+ err = its_pmsi_init_one(domain_handle, node_name);
+
+out:
+ kfree(node_name);
+ return err;
+}
+
+static void __init its_pmsi_acpi_init(void)
+{
+ acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
+ its_pmsi_parse_madt, 0);
+}
+#else
+static inline void its_pmsi_acpi_init(void) { }
+#endif
+
+static void __init its_pmsi_of_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;
+
+ its_pmsi_init_one(of_node_to_fwnode(np), np->full_name);
+ }
+}
+
+static int __init its_pmsi_init(void)
+{
+ its_pmsi_of_init();
+ its_pmsi_acpi_init();
+ return 0;
+}
+early_initcall(its_pmsi_init);