PCI: hv: Fix the definition of vector in hv_compose_msi_msg()

The local variable 'vector' must be u32 rather than u8: see the
struct hv_msi_desc3.

'vector_count' should be u16 rather than u8: see struct hv_msi_desc,
hv_msi_desc2 and hv_msi_desc3.

Fixes: a2bad844a67b ("PCI: hv: Fix interrupt mapping for multi-MSI")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Cc: Jeffrey Hugo <quic_jhugo@quicinc.com>
Cc: Carl Vanderlip <quic_carlv@quicinc.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Link: https://lore.kernel.org/r/20221027205256.17678-1-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index e7c6f66..ba64284 100644 (file)
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -1614,7 +1614,7 @@ out:
 
 static u32 hv_compose_msi_req_v1(
        struct pci_create_interrupt *int_pkt, const struct cpumask *affinity,
-       u32 slot, u8 vector, u8 vector_count)
+       u32 slot, u8 vector, u16 vector_count)
 {
        int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE;
        int_pkt->wslot.slot = slot;
@@ -1642,7 +1642,7 @@ static int hv_compose_msi_req_get_cpu(const struct cpumask *affinity)
 
 static u32 hv_compose_msi_req_v2(
        struct pci_create_interrupt2 *int_pkt, const struct cpumask *affinity,
-       u32 slot, u8 vector, u8 vector_count)
+       u32 slot, u8 vector, u16 vector_count)
 {
        int cpu;
 
@@ -1661,7 +1661,7 @@ static u32 hv_compose_msi_req_v2(
 
 static u32 hv_compose_msi_req_v3(
        struct pci_create_interrupt3 *int_pkt, const struct cpumask *affinity,
-       u32 slot, u32 vector, u8 vector_count)
+       u32 slot, u32 vector, u16 vector_count)
 {
        int cpu;
 
@@ -1701,7 +1701,12 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
        struct compose_comp_ctxt comp;
        struct tran_int_desc *int_desc;
        struct msi_desc *msi_desc;
-       u8 vector, vector_count;
+       /*
+        * vector_count should be u16: see hv_msi_desc, hv_msi_desc2
+        * and hv_msi_desc3. vector must be u32: see hv_msi_desc3.
+        */
+       u16 vector_count;
+       u32 vector;
        struct {
                struct pci_packet pci_pkt;
                union {
@@ -1767,6 +1772,11 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
                vector_count = 1;
        }
 
+       /*
+        * hv_compose_msi_req_v1 and v2 are for x86 only, meaning 'vector'
+        * can't exceed u8. Cast 'vector' down to u8 for v1/v2 explicitly
+        * for better readability.
+        */
        memset(&ctxt, 0, sizeof(ctxt));
        init_completion(&comp.comp_pkt.host_event);
        ctxt.pci_pkt.completion_func = hv_pci_compose_compl;
@@ -1777,7 +1787,7 @@ 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,
-                                       vector,
+                                       (u8)vector,
                                        vector_count);
                break;
 
@@ -1786,7 +1796,7 @@ 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,
-                                       vector,
+                                       (u8)vector,
                                        vector_count);
                break;