[PATCH 03/11] Drivers: hv: Add support to setup percpu vmbus handler

[Naman Jain <namjain@linux.microsoft.com>]

Add a wrapper function - hv_setup_percpu_vmbus_handler(), similar to
hv_setup_vmbus_handler() to allow setting up custom per-cpu VMBus
interrupt handler. This is required for arm64 support, to be added
in MSHV_VTL driver, where per-cpu VMBus interrupt handler will be
set to mshv_vtl_vmbus_isr() for VTL2 (Virtual Trust Level 2).

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
---
 arch/arm64/hyperv/mshyperv.c   | 13 +++++++++++++
 drivers/hv/hv_common.c         | 11 +++++++++++
 drivers/hv/vmbus_drv.c         |  7 +------
 include/asm-generic/mshyperv.h |  3 +++
 4 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c
index 4fdc26ade1d7..d4494ceeaad0 100644
--- a/arch/arm64/hyperv/mshyperv.c
+++ b/arch/arm64/hyperv/mshyperv.c
@@ -134,3 +134,16 @@ bool hv_is_hyperv_initialized(void)
 	return hyperv_initialized;
 }
 EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);
+
+static void (*vmbus_percpu_handler)(void);
+void hv_setup_percpu_vmbus_handler(void (*handler)(void))
+{
+	vmbus_percpu_handler = handler;
+}
+
+irqreturn_t vmbus_percpu_isr(int irq, void *dev_id)
+{
+	if (vmbus_percpu_handler)
+		vmbus_percpu_handler();
+	return IRQ_HANDLED;
+}
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index d1ebc0ebd08f..a5064f558bf6 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -759,6 +759,17 @@ void __weak hv_setup_vmbus_handler(void (*handler)(void))
 }
 EXPORT_SYMBOL_GPL(hv_setup_vmbus_handler);
 
+irqreturn_t __weak vmbus_percpu_isr(int irq, void *dev_id)
+{
+	return IRQ_HANDLED;
+}
+EXPORT_SYMBOL_GPL(vmbus_percpu_isr);
+
+void __weak hv_setup_percpu_vmbus_handler(void (*handler)(void))
+{
+}
+EXPORT_SYMBOL_GPL(hv_setup_percpu_vmbus_handler);
+
 void __weak hv_remove_vmbus_handler(void)
 {
 }
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index bc4fc1951ae1..f99d4f2d3862 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1413,12 +1413,6 @@ void vmbus_isr(void)
 }
 EXPORT_SYMBOL_FOR_MODULES(vmbus_isr, "mshv_vtl");
 
-static irqreturn_t vmbus_percpu_isr(int irq, void *dev_id)
-{
-	vmbus_isr();
-	return IRQ_HANDLED;
-}
-
 static void vmbus_percpu_work(struct work_struct *work)
 {
 	unsigned int cpu = smp_processor_id();
@@ -1520,6 +1514,7 @@ static int vmbus_bus_init(void)
 	if (vmbus_irq == -1) {
 		hv_setup_vmbus_handler(vmbus_isr);
 	} else {
+		hv_setup_percpu_vmbus_handler(vmbus_isr);
 		ret = request_percpu_irq(vmbus_irq, vmbus_percpu_isr,
 				"Hyper-V VMbus", &vmbus_evt);
 		if (ret) {
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 108f135d4fd9..b147a12085e4 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -22,6 +22,7 @@
 #include <linux/bitops.h>
 #include <acpi/acpi_numa.h>
 #include <linux/cpumask.h>
+#include <linux/interrupt.h>
 #include <linux/nmi.h>
 #include <asm/ptrace.h>
 #include <hyperv/hvhdk.h>
@@ -179,6 +180,8 @@ static inline u64 hv_generate_guest_id(u64 kernel_version)
 
 int hv_get_hypervisor_version(union hv_hypervisor_version_info *info);
 
+irqreturn_t vmbus_percpu_isr(int irq, void *dev_id);
+void hv_setup_percpu_vmbus_handler(void (*handler)(void));
 void hv_setup_vmbus_handler(void (*handler)(void));
 void hv_remove_vmbus_handler(void);
 void hv_setup_stimer0_handler(void (*handler)(void));
-- 
2.43.0