[PATCH 2/3] drivers:hv: Export the API to invoke a hypercall on Hyper-V

["K. Y. Srinivasan" <kys@microsoft.com>]

From: Jake Oshins <jakeo@microsoft.com>

This patch exposes the function that hv_vmbus.ko uses to make hypercalls.  This
is necessary for retargeting an interrupt when it is given a new affinity.

Since we are exporting this API, rename the API as it will be visible outside
the hv.c file.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/hv/hv.c        |    9 +++++----
 include/linux/hyperv.h |    1 +
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 6341be8..a7b6c6a 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -89,9 +89,9 @@ static int query_hypervisor_info(void)
 }
 
 /*
- * do_hypercall- Invoke the specified hypercall
+ * hv_do_hypercall- Invoke the specified hypercall
  */
-static u64 do_hypercall(u64 control, void *input, void *output)
+u64 hv_do_hypercall(u64 control, void *input, void *output)
 {
 	u64 input_address = (input) ? virt_to_phys(input) : 0;
 	u64 output_address = (output) ? virt_to_phys(output) : 0;
@@ -132,6 +132,7 @@ static u64 do_hypercall(u64 control, void *input, void *output)
 	return hv_status_lo | ((u64)hv_status_hi << 32);
 #endif /* !x86_64 */
 }
+EXPORT_SYMBOL_GPL(hv_do_hypercall);
 
 #ifdef CONFIG_X86_64
 static cycle_t read_hv_clock_tsc(struct clocksource *arg)
@@ -329,7 +330,7 @@ int hv_post_message(union hv_connection_id connection_id,
 	aligned_msg->payload_size = payload_size;
 	memcpy((void *)aligned_msg->payload, payload, payload_size);
 
-	status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
+	status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
 		& 0xFFFF;
 
 	put_cpu();
@@ -347,7 +348,7 @@ u16 hv_signal_event(void *con_id)
 {
 	u16 status;
 
-	status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & 0xFFFF);
+	status = (hv_do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & 0xFFFF);
 
 	return status;
 }
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 02393b6..ea0a0e3 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -983,6 +983,7 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
 			bool fb_overlap_ok);
 
 int vmbus_cpu_number_to_vp_number(int cpu_number);
+u64 hv_do_hypercall(u64 control, void *input, void *output);
 
 /**
  * VMBUS_DEVICE - macro used to describe a specific hyperv vmbus device
-- 
1.7.4.1