[PATCH 3.19.y-ckt 002/102] [3.19-stable only] Revert "Drivers: hv: vmbus: Add support for VMBus panic notifier handler"

[Kamal Mostafa]

3.19.8-ckt3 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Kamal Mostafa <kamal at canonical.com>

This reverts commit 501f954032a22fef601f2d8514d2222dae4eff13.

New feature; not qualified for -stable kernels.

Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/hv/hyperv_vmbus.h | 11 -----------
 drivers/hv/vmbus_drv.c    | 35 -----------------------------------
 2 files changed, 46 deletions(-)

diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 64318c0..c386d8d 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -49,17 +49,6 @@ enum hv_cpuid_function {
 	HVCPUID_IMPLEMENTATION_LIMITS		= 0x40000005,
 };
 
-#define  HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE   0x400
-
-#define HV_X64_MSR_CRASH_P0   0x40000100
-#define HV_X64_MSR_CRASH_P1   0x40000101
-#define HV_X64_MSR_CRASH_P2   0x40000102
-#define HV_X64_MSR_CRASH_P3   0x40000103
-#define HV_X64_MSR_CRASH_P4   0x40000104
-#define HV_X64_MSR_CRASH_CTL  0x40000105
-
-#define HV_CRASH_CTL_CRASH_NOTIFY 0x8000000000000000
-
 /* Define version of the synthetic interrupt controller. */
 #define HV_SYNIC_VERSION		(1)
 
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 3d2d710..4d6b269 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -35,8 +35,6 @@
 #include <asm/hyperv.h>
 #include <asm/hypervisor.h>
 #include <asm/mshyperv.h>
-#include <linux/notifier.h>
-#include <linux/ptrace.h>
 #include "hyperv_vmbus.h"
 
 static struct acpi_device  *hv_acpi_dev;
@@ -45,31 +43,6 @@ static struct tasklet_struct msg_dpc;
 static struct completion probe_event;
 static int irq;
 
-
-int hyperv_panic_event(struct notifier_block *nb,
-			unsigned long event, void *ptr)
-{
-	struct pt_regs *regs;
-
-	regs = current_pt_regs();
-
-	wrmsrl(HV_X64_MSR_CRASH_P0, regs->ip);
-	wrmsrl(HV_X64_MSR_CRASH_P1, regs->ax);
-	wrmsrl(HV_X64_MSR_CRASH_P2, regs->bx);
-	wrmsrl(HV_X64_MSR_CRASH_P3, regs->cx);
-	wrmsrl(HV_X64_MSR_CRASH_P4, regs->dx);
-
-	/*
-	 * Let Hyper-V know there is crash data available
-	 */
-	wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
-	return NOTIFY_DONE;
-}
-
-static struct notifier_block hyperv_panic_block = {
-	.notifier_call = hyperv_panic_event,
-};
-
 struct resource hyperv_mmio = {
 	.name  = "hyperv mmio",
 	.flags = IORESOURCE_MEM,
@@ -738,14 +711,6 @@ static int vmbus_bus_init(int irq)
 	if (ret)
 		goto err_alloc;
 
-	/*
-	 * Only register if the crash MSRs are available
-	 */
-	if (ms_hyperv.features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
-		atomic_notifier_chain_register(&panic_notifier_list,
-					       &hyperv_panic_block);
-	}
-
 	vmbus_request_offers();
 
 	return 0;
-- 
1.9.1