Drivers: hv: vmbus: Add parsing of VMbus interrupt in ACPI DSDT

On ARM64, Hyper-V now specifies the interrupt to be used by VMbus
in the ACPI DSDT.  This information is not used on x86 because the
interrupt vector must be hardcoded.  But update the generic
VMbus driver to do the parsing and pass the information to the
architecture specific code that sets up the Linux IRQ.  Update
consumers of the interrupt to get it from an architecture specific
function.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1597434304-40631-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

5 files changed, 38 insertions, 6 deletions

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 4f77b8f22e54..ffc289992d1b 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -54,6 +54,7 @@ typedef int (*hyperv_fill_flush_list_func)(
 #define hv_enable_vdso_clocksource() \
 	vclocks_set_used(VDSO_CLOCKMODE_HVCLOCK);
 #define hv_get_raw_timer() rdtsc_ordered()
+#define hv_get_vector() HYPERVISOR_CALLBACK_VECTOR
 
 /*
  * Reference to pv_ops must be inline so objtool
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 9834a43cd0fa..05ef1f4550cb 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -55,9 +55,14 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
 	set_irq_regs(old_regs);
 }
 
-void hv_setup_vmbus_irq(void (*handler)(void))
+int hv_setup_vmbus_irq(int irq, void (*handler)(void))
 {
+	/*
+	 * The 'irq' argument is ignored on x86/x64 because a hard-coded
+	 * interrupt vector is used for Hyper-V interrupts.
+	 */
 	vmbus_handler = handler;
+	return 0;
 }
 
 void hv_remove_vmbus_irq(void)
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 410f1fab519c..0cde10fe0e71 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -180,7 +180,7 @@ void hv_synic_enable_regs(unsigned int cpu)
 	/* Setup the shared SINT. */
 	hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 
-	shared_sint.vector = HYPERVISOR_CALLBACK_VECTOR;
+	shared_sint.vector = hv_get_vector();
 	shared_sint.masked = false;
 	shared_sint.auto_eoi = hv_recommend_using_aeoi();
 	hv_set_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 187809977360..4217646decf1 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -48,6 +48,10 @@ static int hyperv_cpuhp_online;
 
 static void *hv_panic_page;
 
+/* Values parsed from ACPI DSDT */
+static int vmbus_irq;
+int vmbus_interrupt;
+
 /*
  * Boolean to control whether to report panic messages over Hyper-V.
  *
@@ -1347,7 +1351,7 @@ static void vmbus_isr(void)
 			tasklet_schedule(&hv_cpu->msg_dpc);
 	}
 
-	add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
+	add_interrupt_randomness(hv_get_vector(), 0);
 }
 
 /*
@@ -1430,7 +1434,9 @@ static int vmbus_bus_init(void)
 	if (ret)
 		return ret;
 
-	hv_setup_vmbus_irq(vmbus_isr);
+	ret = hv_setup_vmbus_irq(vmbus_irq, vmbus_isr);
+	if (ret)
+		goto err_setup;
 
 	ret = hv_synic_alloc();
 	if (ret)
@@ -1505,7 +1511,7 @@ err_cpuhp:
 	hv_synic_free();
 err_alloc:
 	hv_remove_vmbus_irq();
-
+err_setup:
 	bus_unregister(&hv_bus);
 	unregister_sysctl_table(hv_ctl_table_hdr);
 	hv_ctl_table_hdr = NULL;
@@ -2070,6 +2076,7 @@ static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
 	struct resource *new_res;
 	struct resource **old_res = &hyperv_mmio;
 	struct resource **prev_res = NULL;
+	struct resource r;
 
 	switch (res->type) {
 
@@ -2088,6 +2095,23 @@ static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
 		end = res->data.address64.address.maximum;
 		break;
 
+	/*
+	 * The IRQ information is needed only on ARM64, which Hyper-V
+	 * sets up in the extended format. IRQ information is present
+	 * on x86/x64 in the non-extended format but it is not used by
+	 * Linux. So don't bother checking for the non-extended format.
+	 */
+	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
+		if (!acpi_dev_resource_interrupt(res, 0, &r)) {
+			pr_err("Unable to parse Hyper-V ACPI interrupt\n");
+			return AE_ERROR;
+		}
+		/* ARM64 INTID for VMbus */
+		vmbus_interrupt = res->data.extended_irq.interrupts[0];
+		/* Linux IRQ number */
+		vmbus_irq = r.start;
+		return AE_OK;
+
 	default:
 		/* Unused resource type */
 		return AE_OK;
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index c5edc5e08b94..c57799684170 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -89,7 +89,7 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
 	}
 }
 
-void hv_setup_vmbus_irq(void (*handler)(void));
+int hv_setup_vmbus_irq(int irq, void (*handler)(void));
 void hv_remove_vmbus_irq(void);
 void hv_enable_vmbus_irq(void);
 void hv_disable_vmbus_irq(void);
@@ -99,6 +99,8 @@ void hv_remove_kexec_handler(void);
 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
 void hv_remove_crash_handler(void);
 
+extern int vmbus_interrupt;
+
 #if IS_ENABLED(CONFIG_HYPERV)
 /*
  * Hypervisor's notion of virtual processor ID is different from