[PATCH v3 1/1] PCI: hv: Support for create interrupt v3

[Sunil Muthuswamy]

Hyper-V vPCI protocol version 1_4 adds support for create interrupt
v3. Create interrupt v3 essentially makes the size of the vector
field bigger in the message, thereby allowing bigger vector values.
For example, that will come into play for supporting LPI vectors
on ARM, which start at 8192.

Signed-off-by: Sunil Muthuswamy <sunilmut@xxxxxxxxxxxxx>
---
In V2:
- Addressed comment from Wei Liu

In V3:
- Addressed feedback from Michael Kelley about incorrect comments.
---
 drivers/pci/controller/pci-hyperv.c | 67 ++++++++++++++++++++++++++---
 1 file changed, 62 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index bebe3eeebc4e..8d77dfbb39f8 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -64,6 +64,7 @@ enum pci_protocol_version_t {
 	PCI_PROTOCOL_VERSION_1_1 = PCI_MAKE_VERSION(1, 1),	/* Win10 */
 	PCI_PROTOCOL_VERSION_1_2 = PCI_MAKE_VERSION(1, 2),	/* RS1 */
 	PCI_PROTOCOL_VERSION_1_3 = PCI_MAKE_VERSION(1, 3),	/* Vibranium */
+	PCI_PROTOCOL_VERSION_1_4 = PCI_MAKE_VERSION(1, 4),	/* WS2022 */
 };
 
 #define CPU_AFFINITY_ALL	-1ULL
@@ -73,6 +74,7 @@ enum pci_protocol_version_t {
  * first.
  */
 static enum pci_protocol_version_t pci_protocol_versions[] = {
+	PCI_PROTOCOL_VERSION_1_4,
 	PCI_PROTOCOL_VERSION_1_3,
 	PCI_PROTOCOL_VERSION_1_2,
 	PCI_PROTOCOL_VERSION_1_1,
@@ -122,6 +124,8 @@ enum pci_message_type {
 	PCI_CREATE_INTERRUPT_MESSAGE2	= PCI_MESSAGE_BASE + 0x17,
 	PCI_DELETE_INTERRUPT_MESSAGE2	= PCI_MESSAGE_BASE + 0x18, /* unused */
 	PCI_BUS_RELATIONS2		= PCI_MESSAGE_BASE + 0x19,
+	PCI_RESOURCES_ASSIGNED3         = PCI_MESSAGE_BASE + 0x1A,
+	PCI_CREATE_INTERRUPT_MESSAGE3   = PCI_MESSAGE_BASE + 0x1B,
 	PCI_MESSAGE_MAXIMUM
 };
 
@@ -235,6 +239,21 @@ struct hv_msi_desc2 {
 	u16	processor_array[32];
 } __packed;
 
+/*
+ * struct hv_msi_desc3 - 1.3 version of hv_msi_desc
+ *	Everything is the same as in 'hv_msi_desc2' except that the size of the
+ *	'vector' field is larger to support bigger vector values. For ex: LPI
+ *	vectors on ARM.
+ */
+struct hv_msi_desc3 {
+	u32	vector;
+	u8	delivery_mode;
+	u8	reserved;
+	u16	vector_count;
+	u16	processor_count;
+	u16	processor_array[32];
+} __packed;
+
 /**
  * struct tran_int_desc
  * @reserved:		unused, padding
@@ -383,6 +402,12 @@ struct pci_create_interrupt2 {
 	struct hv_msi_desc2 int_desc;
 } __packed;
 
+struct pci_create_interrupt3 {
+	struct pci_message message_type;
+	union win_slot_encoding wslot;
+	struct hv_msi_desc3 int_desc;
+} __packed;
+
 struct pci_delete_interrupt {
 	struct pci_message message_type;
 	union win_slot_encoding wslot;
@@ -1334,6 +1359,15 @@ static u32 hv_compose_msi_req_v1(
 	return sizeof(*int_pkt);
 }
 
+/*
+ * Create MSI w/ dummy vCPU set targeting just one vCPU, overwritten
+ * by subsequent retarget in hv_irq_unmask().
+ */
+static int hv_compose_msi_req_get_cpu(struct cpumask *affinity)
+{
+	return cpumask_first_and(affinity, cpu_online_mask);
+}
+
 static u32 hv_compose_msi_req_v2(
 	struct pci_create_interrupt2 *int_pkt, struct cpumask *affinity,
 	u32 slot, u8 vector)
@@ -1345,12 +1379,27 @@ static u32 hv_compose_msi_req_v2(
 	int_pkt->int_desc.vector = vector;
 	int_pkt->int_desc.vector_count = 1;
 	int_pkt->int_desc.delivery_mode = APIC_DELIVERY_MODE_FIXED;
+	cpu = hv_compose_msi_req_get_cpu(affinity);
+	int_pkt->int_desc.processor_array[0] =
+		hv_cpu_number_to_vp_number(cpu);
+	int_pkt->int_desc.processor_count = 1;
 
-	/*
-	 * Create MSI w/ dummy vCPU set targeting just one vCPU, overwritten
-	 * by subsequent retarget in hv_irq_unmask().
-	 */
-	cpu = cpumask_first_and(affinity, cpu_online_mask);
+	return sizeof(*int_pkt);
+}
+
+static u32 hv_compose_msi_req_v3(
+	struct pci_create_interrupt3 *int_pkt, struct cpumask *affinity,
+	u32 slot, u32 vector)
+{
+	int cpu;
+
+	int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE3;
+	int_pkt->wslot.slot = slot;
+	int_pkt->int_desc.vector = vector;
+	int_pkt->int_desc.reserved = 0;
+	int_pkt->int_desc.vector_count = 1;
+	int_pkt->int_desc.delivery_mode = APIC_DELIVERY_MODE_FIXED;
+	cpu = hv_compose_msi_req_get_cpu(affinity);
 	int_pkt->int_desc.processor_array[0] =
 		hv_cpu_number_to_vp_number(cpu);
 	int_pkt->int_desc.processor_count = 1;
@@ -1385,6 +1434,7 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 		union {
 			struct pci_create_interrupt v1;
 			struct pci_create_interrupt2 v2;
+			struct pci_create_interrupt3 v3;
 		} int_pkts;
 	} __packed ctxt;
 
@@ -1432,6 +1482,13 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 					cfg->vector);
 		break;
 
+	case PCI_PROTOCOL_VERSION_1_4:
+		size = hv_compose_msi_req_v3(&ctxt.int_pkts.v3,
+					dest,
+					hpdev->desc.win_slot.slot,
+					cfg->vector);
+		break;
+
 	default:
 		/* As we only negotiate protocol versions known to this driver,
 		 * this path should never hit. However, this is it not a hot
-- 
2.17.1