[PATCH RFC v15 12/30] virt: gunyah: Translate gh_rm_hyp_resource into gunyah_resource

[Elliot Berman]

When booting a Gunyah virtual machine, the host VM may gain capabilities
to interact with resources for the guest virtual machine. Examples of
such resources are vCPUs or message queues. To use those resources, we
need to translate the RM response into a gunyah_resource structure which
are useful to Linux drivers. Presently, Linux drivers need only to know
the type of resource, the capability ID, and an interrupt.

On ARM64 systems, the interrupt reported by Gunyah is the GIC interrupt
ID number and always a SPI.

Reviewed-by: Alex Elder <elder@xxxxxxxxxx>
Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
---
 arch/arm64/include/asm/gunyah.h |  36 +++++++++
 drivers/virt/gunyah/rsc_mgr.c   | 174 +++++++++++++++++++++++++++++++++++++++-
 include/linux/gunyah.h          |   3 +
 include/linux/gunyah_rsc_mgr.h  |   5 ++
 4 files changed, 217 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/gunyah.h b/arch/arm64/include/asm/gunyah.h
new file mode 100644
index 000000000000..0cd3debe22b6
--- /dev/null
+++ b/arch/arm64/include/asm/gunyah.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+#ifndef _ASM_GUNYAH_H
+#define _ASM_GUNYAH_H
+
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+
+static inline int arch_gunyah_fill_irq_fwspec_params(u32 virq,
+						 struct irq_fwspec *fwspec)
+{
+	/* Assume that Gunyah gave us an SPI or ESPI; defensively check it */
+	if (WARN(virq < 32, "Unexpected virq: %d\n", virq)) {
+		return -EINVAL;
+	} else if (virq <= 1019) {
+		fwspec->param_count = 3;
+		fwspec->param[0] = 0; /* GIC_SPI */
+		fwspec->param[1] = virq - 32; /* virq 32 -> SPI 0 */
+		fwspec->param[2] = IRQ_TYPE_EDGE_RISING;
+	} else if (WARN(virq < 4096, "Unexpected virq: %d\n", virq)) {
+		return -EINVAL;
+	} else if (virq < 5120) {
+		fwspec->param_count = 3;
+		fwspec->param[0] = 2; /* GIC_ESPI */
+		fwspec->param[1] = virq - 4096; /* virq 4096 -> ESPI 0 */
+		fwspec->param[2] = IRQ_TYPE_EDGE_RISING;
+	} else {
+		WARN(1, "Unexpected virq: %d\n", virq);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+#endif
diff --git a/drivers/virt/gunyah/rsc_mgr.c b/drivers/virt/gunyah/rsc_mgr.c
index 052b3f072a85..acd772deb950 100644
--- a/drivers/virt/gunyah/rsc_mgr.c
+++ b/drivers/virt/gunyah/rsc_mgr.c
@@ -17,6 +17,8 @@
 #include <linux/platform_device.h>
 #include <linux/miscdevice.h>
 
+#include <asm/gunyah.h>
+
 #include "rsc_mgr.h"
 #include "vm_mgr.h"
 
@@ -129,6 +131,7 @@ struct gunyah_rm_message {
  * @send_ready: completion to send messages again
  * @nh: notifier chain for clients interested in RM notification messages
  * @miscdev: /dev/gunyah
+ * @irq_domain: Domain to translate Gunyah hwirqs to Linux irqs
  */
 struct gunyah_rm {
 	struct device *dev;
@@ -147,6 +150,7 @@ struct gunyah_rm {
 	struct blocking_notifier_head nh;
 
 	struct miscdevice miscdev;
+	struct irq_domain *irq_domain;
 };
 
 /**
@@ -187,6 +191,143 @@ static inline int gunyah_rm_error_remap(enum gunyah_rm_error rm_error)
 	}
 }
 
+struct gunyah_irq_chip_data {
+	u32 gunyah_virq;
+};
+
+static struct irq_chip gunyah_rm_irq_chip = {
+	/* clang-format off */
+	.name			= "Gunyah",
+	.irq_enable		= irq_chip_enable_parent,
+	.irq_disable		= irq_chip_disable_parent,
+	.irq_ack		= irq_chip_ack_parent,
+	.irq_mask		= irq_chip_mask_parent,
+	.irq_mask_ack		= irq_chip_mask_ack_parent,
+	.irq_unmask		= irq_chip_unmask_parent,
+	.irq_eoi		= irq_chip_eoi_parent,
+	.irq_set_affinity	= irq_chip_set_affinity_parent,
+	.irq_set_type		= irq_chip_set_type_parent,
+	.irq_set_wake		= irq_chip_set_wake_parent,
+	.irq_set_vcpu_affinity	= irq_chip_set_vcpu_affinity_parent,
+	.irq_retrigger		= irq_chip_retrigger_hierarchy,
+	.irq_get_irqchip_state	= irq_chip_get_parent_state,
+	.irq_set_irqchip_state	= irq_chip_set_parent_state,
+	.flags			= IRQCHIP_SET_TYPE_MASKED |
+				  IRQCHIP_SKIP_SET_WAKE |
+				  IRQCHIP_MASK_ON_SUSPEND,
+	/* clang-format on */
+};
+
+static int gunyah_rm_irq_domain_alloc(struct irq_domain *d, unsigned int virq,
+				      unsigned int nr_irqs, void *arg)
+{
+	struct gunyah_irq_chip_data *chip_data, *spec = arg;
+	struct irq_fwspec parent_fwspec = {};
+	struct gunyah_rm *rm = d->host_data;
+	u32 gunyah_virq = spec->gunyah_virq;
+	int ret;
+
+	if (nr_irqs != 1)
+		return -EINVAL;
+
+	chip_data = kzalloc(sizeof(*chip_data), GFP_KERNEL);
+	if (!chip_data)
+		return -ENOMEM;
+
+	chip_data->gunyah_virq = gunyah_virq;
+
+	ret = irq_domain_set_hwirq_and_chip(d, virq, chip_data->gunyah_virq,
+					    &gunyah_rm_irq_chip, chip_data);
+	if (ret)
+		goto err_free_irq_data;
+
+	parent_fwspec.fwnode = d->parent->fwnode;
+	ret = arch_gunyah_fill_irq_fwspec_params(chip_data->gunyah_virq,
+						 &parent_fwspec);
+	if (ret) {
+		dev_err(rm->dev, "virq translation failed %u: %d\n",
+			chip_data->gunyah_virq, ret);
+		goto err_free_irq_data;
+	}
+
+	ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, &parent_fwspec);
+	if (ret)
+		goto err_free_irq_data;
+
+	return ret;
+err_free_irq_data:
+	kfree(chip_data);
+	return ret;
+}
+
+static void gunyah_rm_irq_domain_free_single(struct irq_domain *d,
+					     unsigned int virq)
+{
+	struct irq_data *irq_data;
+
+	irq_data = irq_domain_get_irq_data(d, virq);
+	if (!irq_data)
+		return;
+
+	kfree(irq_data->chip_data);
+	irq_data->chip_data = NULL;
+}
+
+static void gunyah_rm_irq_domain_free(struct irq_domain *d, unsigned int virq,
+				      unsigned int nr_irqs)
+{
+	unsigned int i;
+
+	for (i = 0; i < nr_irqs; i++)
+		gunyah_rm_irq_domain_free_single(d, virq);
+}
+
+static const struct irq_domain_ops gunyah_rm_irq_domain_ops = {
+	.alloc = gunyah_rm_irq_domain_alloc,
+	.free = gunyah_rm_irq_domain_free,
+};
+
+struct gunyah_resource *
+gunyah_rm_alloc_resource(struct gunyah_rm *rm,
+			 struct gunyah_rm_hyp_resource *hyp_resource)
+{
+	struct gunyah_resource *ghrsc;
+	int ret;
+
+	ghrsc = kzalloc(sizeof(*ghrsc), GFP_KERNEL);
+	if (!ghrsc)
+		return NULL;
+
+	ghrsc->type = hyp_resource->type;
+	ghrsc->capid = le64_to_cpu(hyp_resource->cap_id);
+	ghrsc->irq = IRQ_NOTCONNECTED;
+	ghrsc->rm_label = le32_to_cpu(hyp_resource->resource_label);
+	if (hyp_resource->virq) {
+		struct gunyah_irq_chip_data irq_data = {
+			.gunyah_virq = le32_to_cpu(hyp_resource->virq),
+		};
+
+		ret = irq_domain_alloc_irqs(rm->irq_domain, 1, NUMA_NO_NODE,
+					    &irq_data);
+		if (ret < 0) {
+			dev_err(rm->dev,
+				"Failed to allocate interrupt for resource %d label: %d: %d\n",
+				ghrsc->type, ghrsc->rm_label, ret);
+			kfree(ghrsc);
+			return NULL;
+		}
+		ghrsc->irq = ret;
+	}
+
+	return ghrsc;
+}
+
+void gunyah_rm_free_resource(struct gunyah_resource *ghrsc)
+{
+	irq_dispose_mapping(ghrsc->irq);
+	kfree(ghrsc);
+}
+
 static int gunyah_rm_init_message_payload(struct gunyah_rm_message *message,
 					  const void *msg, size_t hdr_size,
 					  size_t msg_size)
@@ -713,6 +854,8 @@ static int gunyah_rm_probe_rx_msgq(struct gunyah_rm *rm,
 
 static int gunyah_rm_probe(struct platform_device *pdev)
 {
+	struct irq_domain *parent_irq_domain;
+	struct device_node *parent_irq_node;
 	struct gunyah_rm *rm;
 	int ret;
 
@@ -738,15 +881,43 @@ static int gunyah_rm_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	parent_irq_node = of_irq_find_parent(pdev->dev.of_node);
+	if (!parent_irq_node) {
+		dev_err(&pdev->dev,
+			"Failed to find interrupt parent of resource manager\n");
+		return -ENODEV;
+	}
+
+	parent_irq_domain = irq_find_host(parent_irq_node);
+	if (!parent_irq_domain) {
+		dev_err(&pdev->dev,
+			"Failed to find interrupt parent domain of resource manager\n");
+		return -ENODEV;
+	}
+
+	rm->irq_domain = irq_domain_add_hierarchy(parent_irq_domain, 0, 0,
+						  pdev->dev.of_node,
+						  &gunyah_rm_irq_domain_ops,
+						  NULL);
+	if (!rm->irq_domain) {
+		dev_err(&pdev->dev, "Failed to add irq domain\n");
+		return -ENODEV;
+	}
+	rm->irq_domain->host_data = rm;
+
+	rm->miscdev.parent = &pdev->dev;
 	rm->miscdev.name = "gunyah";
 	rm->miscdev.minor = MISC_DYNAMIC_MINOR;
 	rm->miscdev.fops = &gunyah_dev_fops;
 
 	ret = misc_register(&rm->miscdev);
 	if (ret)
-		return ret;
+		goto err_irq_domain;
 
 	return 0;
+err_irq_domain:
+	irq_domain_remove(rm->irq_domain);
+	return ret;
 }
 
 static void gunyah_rm_remove(struct platform_device *pdev)
@@ -754,6 +925,7 @@ static void gunyah_rm_remove(struct platform_device *pdev)
 	struct gunyah_rm *rm = platform_get_drvdata(pdev);
 
 	misc_deregister(&rm->miscdev);
+	irq_domain_remove(rm->irq_domain);
 }
 
 static const struct of_device_id gunyah_rm_of_match[] = {
diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
index ea2c9eecce0e..ecd62d0e36ad 100644
--- a/include/linux/gunyah.h
+++ b/include/linux/gunyah.h
@@ -29,6 +29,9 @@ struct gunyah_resource {
 	enum gunyah_resource_type type;
 	u64 capid;
 	unsigned int irq;
+
+	struct list_head list;
+	u32 rm_label;
 };
 
 /******************************************************************************/
diff --git a/include/linux/gunyah_rsc_mgr.h b/include/linux/gunyah_rsc_mgr.h
index 7bd2bee91f3e..0f61c2b10817 100644
--- a/include/linux/gunyah_rsc_mgr.h
+++ b/include/linux/gunyah_rsc_mgr.h
@@ -163,4 +163,9 @@ int gunyah_rm_vm_set_address_layout(struct gunyah_rm *rm, u16 vmid,
 				    enum gunyah_rm_range_id range_id,
 				    u64 base_address, u64 size);
 
+struct gunyah_resource *
+gunyah_rm_alloc_resource(struct gunyah_rm *rm,
+			 struct gunyah_rm_hyp_resource *hyp_resource);
+void gunyah_rm_free_resource(struct gunyah_resource *ghrsc);
+
 #endif

-- 
2.43.0