[PATCH 1/2] PCI: hv: Make the code arch neutral

[Sunil Muthuswamy <sunilmut@microsoft.com>]

This patch makes the Hyper-V vPCI code architectural neutral by
moving the architectural dependent pieces into arch specific
code. This allows for the implementation of Hyper-V vPCI for
other architecture such as ARM64.

There are no functional changes expected from this patch.

Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
---
 arch/x86/include/asm/hyperv-tlfs.h  | 33 ++++++++++++++++++++++
 arch/x86/include/asm/mshyperv.h     | 25 ++++++++++++++++
 drivers/pci/controller/pci-hyperv.c | 44 +++++++++++++++++++----------
 include/asm-generic/hyperv-tlfs.h   | 33 ----------------------
 4 files changed, 87 insertions(+), 48 deletions(-)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 2322d6bd5883..fdf3d28fbdd5 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/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
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index adccbc209169..9c53dfef360c 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -10,6 +10,7 @@
 #include <asm/nospec-branch.h>
 #include <asm/paravirt.h>
 #include <asm/mshyperv.h>
+#include <asm/msi.h>
 
 typedef int (*hyperv_fill_flush_list_func)(
 		struct hv_guest_mapping_flush_list *flush,
@@ -168,6 +169,30 @@ int hyperv_fill_flush_guest_mapping_list(
 		struct hv_guest_mapping_flush_list *flush,
 		u64 start_gfn, u64 end_gfn);
 
+#define hv_msi_handler			handle_edge_irq
+#define hv_msi_handler_name		"edge"
+#define hv_msi_prepare			pci_msi_prepare
+#define hv_msi_irq_delivery_mode	APIC_DELIVERY_MODE_FIXED
+
+static inline struct irq_domain *hv_msi_parent_vector_domain(void)
+{
+	return x86_vector_domain;
+}
+
+static inline unsigned int hv_msi_get_int_vector(struct irq_data *data)
+{
+	struct irq_cfg *cfg = irqd_cfg(data);
+
+	return cfg->vector;
+}
+
+static inline int hv_pci_arch_init(void)
+{
+	return 0;
+}
+
+static inline void hv_pci_arch_free(void) {}
+
 #ifdef CONFIG_X86_64
 void hv_apic_init(void);
 void __init hv_init_spinlocks(void);
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 62dbe98d1fe1..b7213b57b4ec 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -44,8 +44,8 @@
 #include <linux/delay.h>
 #include <linux/semaphore.h>
 #include <linux/irqdomain.h>
-#include <asm/irqdomain.h>
-#include <asm/apic.h>
+//#include <asm/irqdomain.h>
+//#include <asm/apic.h>
 #include <linux/irq.h>
 #include <linux/msi.h>
 #include <linux/hyperv.h>
@@ -1192,7 +1192,6 @@ static void hv_irq_mask(struct irq_data *data)
 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 hv_pcibus_device *hbus;
 	struct cpumask *dest;
@@ -1221,11 +1220,12 @@ 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
-	 * setting the HV_DEVICE_INTERRUPT_TARGET_MULTICAST flag results in a
+	 * For x64, honoring apic->delivery_mode set to
+	 * APIC_DELIVERY_MODE_FIXED by setting the
+	 * HV_DEVICE_INTERRUPT_TARGET_MULTICAST flag results in a
 	 * spurious interrupt storm. Not doing so does not seem to have a
 	 * negative effect (yet?).
 	 */
@@ -1322,7 +1322,7 @@ static u32 hv_compose_msi_req_v1(
 	int_pkt->wslot.slot = slot;
 	int_pkt->int_desc.vector = vector;
 	int_pkt->int_desc.vector_count = 1;
-	int_pkt->int_desc.delivery_mode = APIC_DELIVERY_MODE_FIXED;
+	int_pkt->int_desc.delivery_mode = hv_msi_irq_delivery_mode;
 
 	/*
 	 * Create MSI w/ dummy vCPU set, overwritten by subsequent retarget in
@@ -1343,7 +1343,7 @@ static u32 hv_compose_msi_req_v2(
 	int_pkt->wslot.slot = slot;
 	int_pkt->int_desc.vector = vector;
 	int_pkt->int_desc.vector_count = 1;
-	int_pkt->int_desc.delivery_mode = APIC_DELIVERY_MODE_FIXED;
+	int_pkt->int_desc.delivery_mode = hv_msi_irq_delivery_mode;
 
 	/*
 	 * Create MSI w/ dummy vCPU set targeting just one vCPU, overwritten
@@ -1370,7 +1370,6 @@ static u32 hv_compose_msi_req_v2(
  */
 static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 {
-	struct irq_cfg *cfg = irqd_cfg(data);
 	struct hv_pcibus_device *hbus;
 	struct vmbus_channel *channel;
 	struct hv_pci_dev *hpdev;
@@ -1420,7 +1419,7 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 		size = hv_compose_msi_req_v1(&ctxt.int_pkts.v1,
 					dest,
 					hpdev->desc.win_slot.slot,
-					cfg->vector);
+					hv_msi_get_int_vector(data));
 		break;
 
 	case PCI_PROTOCOL_VERSION_1_2:
@@ -1428,7 +1427,7 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 		size = hv_compose_msi_req_v2(&ctxt.int_pkts.v2,
 					dest,
 					hpdev->desc.win_slot.slot,
-					cfg->vector);
+					hv_msi_get_int_vector(data));
 		break;
 
 	default:
@@ -1544,7 +1543,7 @@ static struct irq_chip hv_msi_irq_chip = {
 };
 
 static struct msi_domain_ops hv_msi_ops = {
-	.msi_prepare	= pci_msi_prepare,
+	.msi_prepare	= hv_msi_prepare,
 	.msi_free	= hv_msi_free,
 };
 
@@ -1563,17 +1562,26 @@ static struct msi_domain_ops hv_msi_ops = {
  */
 static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus)
 {
+	struct irq_domain *parent_domain;
+
+	parent_domain = hv_msi_parent_vector_domain();
+	if (!parent_domain) {
+		dev_err(&hbus->hdev->device,
+		    "Failed to get parent MSI domain\n");
+		return -ENODEV;
+	}
+
 	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 = handle_edge_irq;
-	hbus->msi_info.handler_name = "edge";
+	hbus->msi_info.handler = hv_msi_handler;
+	hbus->msi_info.handler_name = hv_msi_handler_name;
 	hbus->msi_info.data = hbus;
 	hbus->irq_domain = pci_msi_create_irq_domain(hbus->fwnode,
 						     &hbus->msi_info,
-						     x86_vector_domain);
+						     parent_domain);
 	if (!hbus->irq_domain) {
 		dev_err(&hbus->hdev->device,
 			"Failed to build an MSI IRQ domain\n");
@@ -3478,9 +3486,15 @@ 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_arch_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);
 
diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
index 56348a541c50..45cc0c3b8ed7 100644
--- a/include/asm-generic/hyperv-tlfs.h
+++ b/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;
 
-- 
2.25.1