Drivers: hv: vmbus: Get rid of MSR access from vmbus_drv.c

Get rid of ISA specific code from vmus_drv.c which is common code.

Fixes: 81b18bce48af ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic")

Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/x86/include/asm/mshyperv.h

@@ -97,6 +97,9 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
 #define hv_set_synint_state(int_num, val) \
 	wrmsrl(HV_X64_MSR_SINT0 + int_num, val)
 
+#define hv_get_crash_ctl(val) \
+	rdmsrl(HV_X64_MSR_CRASH_CTL, val)
+
 void hyperv_callback_vector(void);
 void hyperv_reenlightenment_vector(void);
 #ifdef CONFIG_TRACING

drivers/hv/vmbus_drv.c

@@ -1146,7 +1146,7 @@ static int vmbus_bus_init(void)
 		 * Register for panic kmsg callback only if the right
 		 * capability is supported by the hypervisor.
 		 */
-		rdmsrl(HV_X64_MSR_CRASH_CTL, hyperv_crash_ctl);
+		hv_get_crash_ctl(hyperv_crash_ctl);
 		if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) {
 			hv_panic_page = (void *)get_zeroed_page(GFP_KERNEL);
 			if (hv_panic_page) {