staging: fsl-mc: Added GICv3-ITS support for FSL-MC MSIs

Added platform-specific MSI support layer for FSL-MC devices.
Signed-off-by: J. German Rivera <German.Rivera@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/fsl-mc/bus/Makefile

@@ -14,5 +14,6 @@ mc-bus-driver-objs := mc-bus.o \
 		      dprc-driver.o \
 		      mc-allocator.o \
 		      mc-msi.o \
+		      irq-gic-v3-its-fsl-mc-msi.o \
 		      dpmcp.o \
 		      dpbp.o

drivers/staging/fsl-mc/bus/irq-gic-v3-its-fsl-mc-msi.c

+/*
+ * Freescale Management Complex (MC) bus driver MSI support
+ *
+ * Copyright (C) 2015 Freescale Semiconductor, Inc.
+ * Author: German Rivera <German.Rivera@freescale.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include "../include/mc-private.h"
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/irqchip/arm-gic-v3.h>
+#include <linux/irq.h>
+#include <linux/msi.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include "../include/mc-sys.h"
+#include "dprc-cmd.h"
+
+static struct irq_chip its_msi_irq_chip = {
+	.name = "fsl-mc-bus-msi",
+	.irq_mask = irq_chip_mask_parent,
+	.irq_unmask = irq_chip_unmask_parent,
+	.irq_eoi = irq_chip_eoi_parent,
+	.irq_set_affinity = msi_domain_set_affinity
+};
+
+static int its_fsl_mc_msi_prepare(struct irq_domain *msi_domain,
+				  struct device *dev,
+				  int nvec, msi_alloc_info_t *info)
+{
+	struct fsl_mc_device *mc_bus_dev;
+	struct msi_domain_info *msi_info;
+
+	if (WARN_ON(dev->bus != &fsl_mc_bus_type))
+		return -EINVAL;
+
+	mc_bus_dev = to_fsl_mc_device(dev);
+	if (WARN_ON(!(mc_bus_dev->flags & FSL_MC_IS_DPRC)))
+		return -EINVAL;
+
+	/*
+	 * Set the device Id to be passed to the GIC-ITS:
+	 *
+	 * NOTE: This device id corresponds to the IOMMU stream ID
+	 * associated with the DPRC object (ICID).
+	 */
+	info->scratchpad[0].ul = mc_bus_dev->icid;
+	msi_info = msi_get_domain_info(msi_domain->parent);
+	return msi_info->ops->msi_prepare(msi_domain->parent, dev, nvec, info);
+}
+
+static struct msi_domain_ops its_fsl_mc_msi_ops = {
+	.msi_prepare = its_fsl_mc_msi_prepare,
+};
+
+static struct msi_domain_info its_fsl_mc_msi_domain_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
+	.ops	= &its_fsl_mc_msi_ops,
+	.chip	= &its_msi_irq_chip,
+};
+
+static const struct of_device_id its_device_id[] = {
+	{	.compatible	= "arm,gic-v3-its",	},
+	{},
+};
+
+int __init its_fsl_mc_msi_init(void)
+{
+	struct device_node *np;
+	struct irq_domain *parent;
+	struct irq_domain *mc_msi_domain;
+
+	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;
+		}
+
+		mc_msi_domain = fsl_mc_msi_create_irq_domain(
+						 of_node_to_fwnode(np),
+						 &its_fsl_mc_msi_domain_info,
+						 parent);
+		if (!mc_msi_domain) {
+			pr_err("%s: unable to create fsl-mc domain\n",
+			       np->full_name);
+			continue;
+		}
+
+		WARN_ON(mc_msi_domain->
+				host_data != &its_fsl_mc_msi_domain_info);
+
+		pr_info("fsl-mc MSI: %s domain created\n", np->full_name);
+	}
+
+	return 0;
+}
+
+void its_fsl_mc_msi_cleanup(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)) {
+		struct irq_domain *mc_msi_domain = irq_find_matching_host(
+							np,
+							DOMAIN_BUS_FSL_MC_MSI);
+
+		if (!of_property_read_bool(np, "msi-controller"))
+			continue;
+
+		mc_msi_domain = irq_find_matching_host(np,
+						       DOMAIN_BUS_FSL_MC_MSI);
+		if (mc_msi_domain &&
+		    mc_msi_domain->host_data == &its_fsl_mc_msi_domain_info)
+			irq_domain_remove(mc_msi_domain);
+	}
+}

drivers/staging/fsl-mc/include/mc-private.h

@@ -133,4 +133,8 @@ int fsl_mc_msi_domain_alloc_irqs(struct device *dev,
 
 void fsl_mc_msi_domain_free_irqs(struct device *dev);
 
+int __init its_fsl_mc_msi_init(void);
+
+void its_fsl_mc_msi_cleanup(void);
+
 #endif /* _FSL_MC_PRIVATE_H_ */