Merge branch 'hv-msi-parent-domain' into main

Nam Cao says:

====================
Subject: [PATCH for-netdev v2 0/2] PCI: hv: MSI parent domain conversion

This series originally belongs to a bigger series sent to PCI tree:
https://lore.kernel.org/linux-pci/024f0122314198fe0a42fef01af53e8953a687ec.1750858083.git.namcao@linutronix.de/

However, during review, we noticed that the patch conflicts with another
patch in netdev tree:
https://lore.kernel.org/netdev/1749651015-9668-1-git-send-email-shradhagupta@linux.microsoft.com/

As this series has no dependency with the rest of the series, we think it
is best to split out this one and send it to netdev, to avoid conflict
resolution headache later on.

Can netdev maintainers please pick it up?
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 85 insertions, 28 deletions

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 9c0e4aaf4e8c..9a249c65aedc 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -223,6 +223,7 @@ config PCI_HYPERV
 	tristate "Hyper-V PCI Frontend"
 	depends on ((X86 && X86_64) || ARM64) && HYPERV && PCI_MSI && SYSFS
 	select PCI_HYPERV_INTERFACE
+	select IRQ_MSI_LIB
 	help
 	  The PCI device frontend driver allows the kernel to import arbitrary
 	  PCI devices from a PCI backend to support PCI driver domains.
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 86ca041bf74a..ebe39218479a 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -44,6 +44,7 @@
 #include <linux/delay.h>
 #include <linux/semaphore.h>
 #include <linux/irq.h>
+#include <linux/irqchip/irq-msi-lib.h>
 #include <linux/msi.h>
 #include <linux/hyperv.h>
 #include <linux/refcount.h>
@@ -508,7 +509,6 @@ struct hv_pcibus_device {
 	struct list_head children;
 	struct list_head dr_list;
 
-	struct msi_domain_info msi_info;
 	struct irq_domain *irq_domain;
 
 	struct workqueue_struct *wq;
@@ -576,9 +576,8 @@ struct hv_pci_compl {
 static void hv_pci_onchannelcallback(void *context);
 
 #ifdef CONFIG_X86
-#define DELIVERY_MODE	APIC_DELIVERY_MODE_FIXED
-#define FLOW_HANDLER	handle_edge_irq
-#define FLOW_NAME	"edge"
+#define DELIVERY_MODE		APIC_DELIVERY_MODE_FIXED
+#define HV_MSI_CHIP_FLAGS	MSI_CHIP_FLAG_SET_ACK
 
 static int hv_pci_irqchip_init(void)
 {
@@ -723,8 +722,7 @@ out:
 #define HV_PCI_MSI_SPI_START	64
 #define HV_PCI_MSI_SPI_NR	(1020 - HV_PCI_MSI_SPI_START)
 #define DELIVERY_MODE		0
-#define FLOW_HANDLER		NULL
-#define FLOW_NAME		NULL
+#define HV_MSI_CHIP_FLAGS	MSI_CHIP_FLAG_SET_EOI
 #define hv_msi_prepare		NULL
 
 struct hv_pci_chip_data {
@@ -1687,7 +1685,7 @@ static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info,
 	struct msi_desc *msi = irq_data_get_msi_desc(irq_data);
 
 	pdev = msi_desc_to_pci_dev(msi);
-	hbus = info->data;
+	hbus = domain->host_data;
 	int_desc = irq_data_get_irq_chip_data(irq_data);
 	if (!int_desc)
 		return;
@@ -1705,7 +1703,6 @@ static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info,
 
 static void hv_irq_mask(struct irq_data *data)
 {
-	pci_msi_mask_irq(data);
 	if (data->parent_data->chip->irq_mask)
 		irq_chip_mask_parent(data);
 }
@@ -1716,7 +1713,6 @@ static void hv_irq_unmask(struct irq_data *data)
 
 	if (data->parent_data->chip->irq_unmask)
 		irq_chip_unmask_parent(data);
-	pci_msi_unmask_irq(data);
 }
 
 struct compose_comp_ctxt {
@@ -2101,25 +2097,87 @@ return_null_message:
 	msg->data = 0;
 }
 
+static bool hv_pcie_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
+				      struct irq_domain *real_parent, struct msi_domain_info *info)
+{
+	struct irq_chip *chip = info->chip;
+
+	if (!msi_lib_init_dev_msi_info(dev, domain, real_parent, info))
+		return false;
+
+	info->ops->msi_prepare = hv_msi_prepare;
+
+	chip->irq_set_affinity = irq_chip_set_affinity_parent;
+
+	if (IS_ENABLED(CONFIG_X86))
+		chip->flags |= IRQCHIP_MOVE_DEFERRED;
+
+	return true;
+}
+
+#define HV_PCIE_MSI_FLAGS_REQUIRED (MSI_FLAG_USE_DEF_DOM_OPS		| \
+				    MSI_FLAG_USE_DEF_CHIP_OPS		| \
+				    MSI_FLAG_PCI_MSI_MASK_PARENT)
+#define HV_PCIE_MSI_FLAGS_SUPPORTED (MSI_FLAG_MULTI_PCI_MSI		| \
+				     MSI_FLAG_PCI_MSIX			| \
+				     MSI_FLAG_PCI_MSIX_ALLOC_DYN	| \
+				     MSI_GENERIC_FLAGS_MASK)
+
+static const struct msi_parent_ops hv_pcie_msi_parent_ops = {
+	.required_flags		= HV_PCIE_MSI_FLAGS_REQUIRED,
+	.supported_flags	= HV_PCIE_MSI_FLAGS_SUPPORTED,
+	.bus_select_token	= DOMAIN_BUS_PCI_MSI,
+	.chip_flags		= HV_MSI_CHIP_FLAGS,
+	.prefix			= "HV-",
+	.init_dev_msi_info	= hv_pcie_init_dev_msi_info,
+};
+
 /* HW Interrupt Chip Descriptor */
 static struct irq_chip hv_msi_irq_chip = {
 	.name			= "Hyper-V PCIe MSI",
 	.irq_compose_msi_msg	= hv_compose_msi_msg,
 	.irq_set_affinity	= irq_chip_set_affinity_parent,
-#ifdef CONFIG_X86
 	.irq_ack		= irq_chip_ack_parent,
-	.flags			= IRQCHIP_MOVE_DEFERRED,
-#elif defined(CONFIG_ARM64)
 	.irq_eoi		= irq_chip_eoi_parent,
-#endif
 	.irq_mask		= hv_irq_mask,
 	.irq_unmask		= hv_irq_unmask,
 };
 
-static struct msi_domain_ops hv_msi_ops = {
-	.msi_prepare	= hv_msi_prepare,
-	.msi_free	= hv_msi_free,
-	.prepare_desc	= pci_msix_prepare_desc,
+static int hv_pcie_domain_alloc(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs,
+			       void *arg)
+{
+	/*
+	 * TODO: Allocating and populating struct tran_int_desc in hv_compose_msi_msg()
+	 * should be moved here.
+	 */
+	int ret;
+
+	ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, arg);
+	if (ret < 0)
+		return ret;
+
+	for (int i = 0; i < nr_irqs; i++) {
+		irq_domain_set_hwirq_and_chip(d, virq + i, 0, &hv_msi_irq_chip, NULL);
+		if (IS_ENABLED(CONFIG_X86))
+			__irq_set_handler(virq + i, handle_edge_irq, 0, "edge");
+	}
+
+	return 0;
+}
+
+static void hv_pcie_domain_free(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs)
+{
+	struct msi_domain_info *info = d->host_data;
+
+	for (int i = 0; i < nr_irqs; i++)
+		hv_msi_free(d, info, virq + i);
+
+	irq_domain_free_irqs_top(d, virq, nr_irqs);
+}
+
+static const struct irq_domain_ops hv_pcie_domain_ops = {
+	.alloc	= hv_pcie_domain_alloc,
+	.free	= hv_pcie_domain_free,
 };
 
 /**
@@ -2137,17 +2195,14 @@ static struct msi_domain_ops hv_msi_ops = {
  */
 static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus)
 {
-	hbus->msi_info.chip = &hv_msi_irq_chip;
-	hbus->msi_info.ops = &hv_msi_ops;
-	hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS |
-		MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI |
-		MSI_FLAG_PCI_MSIX | MSI_FLAG_PCI_MSIX_ALLOC_DYN);
-	hbus->msi_info.handler = FLOW_HANDLER;
-	hbus->msi_info.handler_name = FLOW_NAME;
-	hbus->msi_info.data = hbus;
-	hbus->irq_domain = pci_msi_create_irq_domain(hbus->fwnode,
-						     &hbus->msi_info,
-						     hv_pci_get_root_domain());
+	struct irq_domain_info info = {
+		.fwnode		= hbus->fwnode,
+		.ops		= &hv_pcie_domain_ops,
+		.host_data	= hbus,
+		.parent		= hv_pci_get_root_domain(),
+	};
+
+	hbus->irq_domain = msi_create_parent_irq_domain(&info, &hv_pcie_msi_parent_ops);
 	if (!hbus->irq_domain) {
 		dev_err(&hbus->hdev->device,
 			"Failed to build an MSI IRQ domain\n");
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index c8b6de09047b..46919e6c9c45 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -1561,6 +1561,7 @@ void irq_domain_free_irqs_top(struct irq_domain *domain, unsigned int virq,
 	}
 	irq_domain_free_irqs_common(domain, virq, nr_irqs);
 }
+EXPORT_SYMBOL_GPL(irq_domain_free_irqs_top);
 
 static void irq_domain_free_irqs_hierarchy(struct irq_domain *domain,
 					   unsigned int irq_base,