irqchip/gicv3-its: Add platform MSI support
In order to support non-PCI MSI with the GICv3 ITS, add the minimal
required entry points for the MSI domain (an msi_prepare implementation).
The rest is only boilerplate code to find the raw ITS domain.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Ma Jun <majun258@huawei.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Duc Dang <dhdang@apm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1438091186-10244-16-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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 0000000..a865505
--- /dev/null
+++ b/drivers/irqchip/irq-gic-v3-its-platform-msi.c
@@ -0,0 +1,93 @@
+/*
+ * 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/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 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);
+
+ /* Suck the DeviceID out of the msi-parent property */
+ ret = of_property_read_u32_index(dev->of_node, "msi-parent",
+ 1, &dev_id);
+ if (ret)
+ return ret;
+
+ /* ITS specific DeviceID, as the core ITS ignores dev. */
+ info->scratchpad[0].ul = dev_id;
+
+ 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 struct of_device_id its_device_id[] = {
+ { .compatible = "arm,gic-v3-its", },
+ {},
+};
+
+static int __init its_pmsi_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 (!platform_msi_create_irq_domain(np, &its_pmsi_domain_info,
+ parent)) {
+ pr_err("%s: unable to create platform domain\n",
+ np->full_name);
+ continue;
+ }
+
+ pr_info("Platform MSI: %s domain created\n", np->full_name);
+ }
+
+ return 0;
+}
+early_initcall(its_pmsi_init);