PCI: hv: Make the code arch neutral by adding arch specific interfaces

Encapsulate arch dependencies in Hyper-V vPCI through a set of
arch-dependent interfaces. Adding these arch specific interfaces will
allow for an implementation for other architectures, such as arm64.

There are no functional changes expected from this patch.

Link: https://lore.kernel.org/r/1641411156-31705-2-git-send-email-sunilmut@linux.microsoft.com
Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Allen Pais <apais@linux.microsoft.com>

arch/x86/include/asm/hyperv-tlfs.h

@@ -585,6 +585,39 @@ enum hv_interrupt_type {
 	HV_X64_INTERRUPT_TYPE_MAXIMUM           = 0x000A,
 };
 
+union hv_msi_address_register {
+	u32 as_uint32;
+	struct {
+		u32 reserved1:2;
+		u32 destination_mode:1;
+		u32 redirection_hint:1;
+		u32 reserved2:8;
+		u32 destination_id:8;
+		u32 msi_base:12;
+	};
+} __packed;
+
+union hv_msi_data_register {
+	u32 as_uint32;
+	struct {
+		u32 vector:8;
+		u32 delivery_mode:3;
+		u32 reserved1:3;
+		u32 level_assert:1;
+		u32 trigger_mode:1;
+		u32 reserved2:16;
+	};
+} __packed;
+
+/* HvRetargetDeviceInterrupt hypercall */
+union hv_msi_entry {
+	u64 as_uint64;
+	struct {
+		union hv_msi_address_register address;
+		union hv_msi_data_register data;
+	} __packed;
+};
+
 #include <asm-generic/hyperv-tlfs.h>
 
 #endif

drivers/pci/controller/pci-hyperv.c

@@ -43,9 +43,6 @@
 #include <linux/pci-ecam.h>
 #include <linux/delay.h>
 #include <linux/semaphore.h>
-#include <linux/irqdomain.h>
-#include <asm/irqdomain.h>
-#include <asm/apic.h>
 #include <linux/irq.h>
 #include <linux/msi.h>
 #include <linux/hyperv.h>
@@ -577,6 +574,42 @@ 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"
+
+static int hv_pci_irqchip_init(void)
+{
+	return 0;
+}
+
+static struct irq_domain *hv_pci_get_root_domain(void)
+{
+	return x86_vector_domain;
+}
+
+static unsigned int hv_msi_get_int_vector(struct irq_data *data)
+{
+	struct irq_cfg *cfg = irqd_cfg(data);
+
+	return cfg->vector;
+}
+
+static void hv_set_msi_entry_from_desc(union hv_msi_entry *msi_entry,
+				       struct msi_desc *msi_desc)
+{
+	msi_entry->address.as_uint32 = msi_desc->msg.address_lo;
+	msi_entry->data.as_uint32 = msi_desc->msg.data;
+}
+
+static int hv_msi_prepare(struct irq_domain *domain, struct device *dev,
+			  int nvec, msi_alloc_info_t *info)
+{
+	return pci_msi_prepare(domain, dev, nvec, info);
+}
+#endif /* CONFIG_X86 */
+
 /**
  * hv_pci_generic_compl() - Invoked for a completion packet
  * @context:		Set up by the sender of the packet.
@@ -1189,14 +1222,6 @@ static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info,
 	put_pcichild(hpdev);
 }
 
-static int hv_set_affinity(struct irq_data *data, const struct cpumask *dest,
-			   bool force)
-{
-	struct irq_data *parent = data->parent_data;
-
-	return parent->chip->irq_set_affinity(parent, dest, force);
-}
-
 static void hv_irq_mask(struct irq_data *data)
 {
 	pci_msi_mask_irq(data);
@@ -1237,7 +1262,6 @@ static int hv_msi_prepare(struct irq_domain *domain, struct device *dev,
 static void hv_irq_unmask(struct irq_data *data)
 {
 	struct msi_desc *msi_desc = irq_data_get_msi_desc(data);
-	struct irq_cfg *cfg = irqd_cfg(data);
 	struct hv_retarget_device_interrupt *params;
 	struct tran_int_desc *int_desc;
 	struct hv_pcibus_device *hbus;
@@ -1274,7 +1298,7 @@ static void hv_irq_unmask(struct irq_data *data)
 			   (hbus->hdev->dev_instance.b[7] << 8) |
 			   (hbus->hdev->dev_instance.b[6] & 0xf8) |
 			   PCI_FUNC(pdev->devfn);
-	params->int_target.vector = cfg->vector;
+	params->int_target.vector = hv_msi_get_int_vector(data);
 
 	/*
 	 * Honoring apic->delivery_mode set to APIC_DELIVERY_MODE_FIXED by
@@ -1375,7 +1399,7 @@ static u32 hv_compose_msi_req_v1(
 	int_pkt->wslot.slot = slot;
 	int_pkt->int_desc.vector = vector;
 	int_pkt->int_desc.vector_count = vector_count;
-	int_pkt->int_desc.delivery_mode = APIC_DELIVERY_MODE_FIXED;
+	int_pkt->int_desc.delivery_mode = DELIVERY_MODE;
 
 	/*
 	 * Create MSI w/ dummy vCPU set, overwritten by subsequent retarget in
@@ -1405,7 +1429,7 @@ static u32 hv_compose_msi_req_v2(
 	int_pkt->wslot.slot = slot;
 	int_pkt->int_desc.vector = vector;
 	int_pkt->int_desc.vector_count = vector_count;
-	int_pkt->int_desc.delivery_mode = APIC_DELIVERY_MODE_FIXED;
+	int_pkt->int_desc.delivery_mode = DELIVERY_MODE;
 	cpu = hv_compose_msi_req_get_cpu(affinity);
 	int_pkt->int_desc.processor_array[0] =
 		hv_cpu_number_to_vp_number(cpu);
@@ -1425,7 +1449,7 @@ static u32 hv_compose_msi_req_v3(
 	int_pkt->int_desc.vector = vector;
 	int_pkt->int_desc.reserved = 0;
 	int_pkt->int_desc.vector_count = vector_count;
-	int_pkt->int_desc.delivery_mode = APIC_DELIVERY_MODE_FIXED;
+	int_pkt->int_desc.delivery_mode = DELIVERY_MODE;
 	cpu = hv_compose_msi_req_get_cpu(affinity);
 	int_pkt->int_desc.processor_array[0] =
 		hv_cpu_number_to_vp_number(cpu);
@@ -1653,7 +1677,7 @@ return_null_message:
 static struct irq_chip hv_msi_irq_chip = {
 	.name			= "Hyper-V PCIe MSI",
 	.irq_compose_msi_msg	= hv_compose_msi_msg,
-	.irq_set_affinity	= hv_set_affinity,
+	.irq_set_affinity	= irq_chip_set_affinity_parent,
 	.irq_ack		= irq_chip_ack_parent,
 	.irq_mask		= hv_irq_mask,
 	.irq_unmask		= hv_irq_unmask,
@@ -1684,12 +1708,12 @@ static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus)
 	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 = handle_edge_irq;
+	hbus->msi_info.handler = FLOW_HANDLER;
-	hbus->msi_info.handler_name = "edge";
+	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,
-						     x86_vector_domain);
+						     hv_pci_get_root_domain());
 	if (!hbus->irq_domain) {
 		dev_err(&hbus->hdev->device,
 			"Failed to build an MSI IRQ domain\n");
@@ -3651,9 +3675,15 @@ static void __exit exit_hv_pci_drv(void)
 
 static int __init init_hv_pci_drv(void)
 {
+	int ret;
+
 	if (!hv_is_hyperv_initialized())
 		return -ENODEV;
 
+	ret = hv_pci_irqchip_init();
+	if (ret)
+		return ret;
+
 	/* Set the invalid domain number's bit, so it will not be used */
 	set_bit(HVPCI_DOM_INVALID, hvpci_dom_map);
 

include/asm-generic/hyperv-tlfs.h

@@ -539,39 +539,6 @@ enum hv_interrupt_source {
 	HV_INTERRUPT_SOURCE_IOAPIC,
 };
 
-union hv_msi_address_register {
-	u32 as_uint32;
-	struct {
-		u32 reserved1:2;
-		u32 destination_mode:1;
-		u32 redirection_hint:1;
-		u32 reserved2:8;
-		u32 destination_id:8;
-		u32 msi_base:12;
-	};
-} __packed;
-
-union hv_msi_data_register {
-	u32 as_uint32;
-	struct {
-		u32 vector:8;
-		u32 delivery_mode:3;
-		u32 reserved1:3;
-		u32 level_assert:1;
-		u32 trigger_mode:1;
-		u32 reserved2:16;
-	};
-} __packed;
-
-/* HvRetargetDeviceInterrupt hypercall */
-union hv_msi_entry {
-	u64 as_uint64;
-	struct {
-		union hv_msi_address_register address;
-		union hv_msi_data_register data;
-	} __packed;
-};
-
 union hv_ioapic_rte {
 	u64 as_uint64;