[PATCH 14/16] PCI: hv: Switch to msi_create_parent_irq_domain()

[Nam Cao <namcao@linutronix.de>]

Move away from the legacy MSI domain setup, switch to use
msi_create_parent_irq_domain().

Signed-off-by: Nam Cao <namcao@linutronix.de>
---
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: linux-hyperv@vger.kernel.org
---
 drivers/pci/Kconfig                 |  1 +
 drivers/pci/controller/pci-hyperv.c | 98 +++++++++++++++++++++++------
 2 files changed, 80 insertions(+), 19 deletions(-)

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 9c0e4aaf4e8cb..9a249c65aedcd 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 ef5d655a0052c..3a24fadddb83b 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;
@@ -1687,7 +1687,7 @@ 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 +1705,6 @@ 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 +1715,6 @@ 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 {
@@ -2101,6 +2099,44 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 	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_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,
+#ifdef CONFIG_X86
+	.chip_flags		= MSI_CHIP_FLAG_SET_ACK,
+#elif defined(CONFIG_ARM64)
+	.chip_flags		= MSI_CHIP_FLAG_SET_EOI,
+#endif
+	.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",
@@ -2108,7 +2144,6 @@ static struct irq_chip hv_msi_irq_chip = {
 	.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
@@ -2116,9 +2151,37 @@ static struct irq_chip hv_msi_irq_chip = {
 	.irq_unmask		= hv_irq_unmask,
 };
 
-static struct msi_domain_ops hv_msi_ops = {
-	.msi_prepare	= hv_msi_prepare,
-	.msi_free	= hv_msi_free,
+static int hv_pcie_domain_alloc(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs,
+			       void *arg)
+{
+	/* TODO: move the content of hv_compose_msi_msg() in 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_info(d, virq + i, 0, &hv_msi_irq_chip, NULL, FLOW_HANDLER, NULL,
+				    FLOW_NAME);
+	}
+
+	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,
 };
 
 /**
@@ -2136,17 +2199,14 @@ 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);
-	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");
-- 
2.39.5