Fix IntLock regression in commit 15e64ac.

This corrects interrupt/spinlock acquision code regressed
previously. Locking in the driver is now the same as
prior to that point, and basic functionality is restored.

Initial regression testing has been performed. There are
however, some outstanding questions as to whether the driver
performs correctly in the crashdump/hibernation path.

I will be performing additional regression testing for
those cases, and MSI(X), and issuing further patches
if necessary.

Ref: Nutanix ENG-741981.

Signed-off-by: Martin Harvey <[email protected]>

Author: MartinCHarvey-Nutanix

vioscsi/helper.c

@@ -52,7 +52,6 @@ VOID SendSRB(IN PVOID DeviceExtension, IN PSRB_TYPE Srb)
     ULONG QueueNumber = VIRTIO_SCSI_REQUEST_QUEUE_0;
     BOOLEAN notify = FALSE;
     STOR_LOCK_HANDLE LockHandle = {0};
-    PVOID LockContext;
     ULONG status = STOR_STATUS_SUCCESS;
     UCHAR ScsiStatus = SCSISTAT_GOOD;
     INT add_buffer_req_status = VQ_ADD_BUFFER_SUCCESS;
@@ -107,7 +106,6 @@ VOID SendSRB(IN PVOID DeviceExtension, IN PSRB_TYPE Srb)
     }
 
     vq_req_idx = QueueNumber - VIRTIO_SCSI_REQUEST_QUEUE_0;
-    LockContext = &adaptExt->dpc[vq_req_idx];
 
     if (adaptExt->reset_in_progress)
     {
@@ -117,7 +115,7 @@ VOID SendSRB(IN PVOID DeviceExtension, IN PSRB_TYPE Srb)
         return;
     }
 
-    StorPortAcquireSpinLock(DeviceExtension, DpcLock, LockContext, &LockHandle);
+    StorPortAcquireSpinLock(DeviceExtension, DpcLock, &adaptExt->dpc[vq_req_idx], &LockHandle);
     SET_VA_PA();
     add_buffer_req_status = virtqueue_add_buf(adaptExt->vq[QueueNumber],
                                               srbExt->psgl,

vioscsi/helper.h

@@ -130,7 +130,7 @@ SynchronizedKickEventRoutine(IN PVOID DeviceExtension, IN PVOID Context);
 
 VOID VioScsiCompleteDpcRoutine(IN PSTOR_DPC Dpc, IN PVOID Context, IN PVOID SystemArgument1, IN PVOID SystemArgument2);
 
-VOID ProcessBuffer(IN PVOID DeviceExtension, IN ULONG MessageId, IN STOR_SPINLOCK LockMode);
+VOID ProcessBuffer(IN PVOID DeviceExtension, IN ULONG MessageId, IN BOOLEAN DumpModeNoSync);
 
 VOID
 // FORCEINLINE

vioscsi/vioscsi.c

@@ -1013,7 +1013,7 @@ VioScsiInterrupt(IN PVOID DeviceExtension)
         }
         else
         {
-            ProcessBuffer(DeviceExtension, QUEUE_TO_MESSAGE(VIRTIO_SCSI_REQUEST_QUEUE_0), InterruptLock);
+            ProcessBuffer(DeviceExtension, QUEUE_TO_MESSAGE(VIRTIO_SCSI_REQUEST_QUEUE_0), TRUE);
         }
     }
 
@@ -1243,14 +1243,12 @@ VioScsiUnitControl(IN PVOID DeviceExtension, IN SCSI_UNIT_CONTROL_TYPE ControlTy
             ULONG vq_req_idx;
             PREQUEST_LIST element;
             STOR_LOCK_HANDLE LockHandle = {0};
-            PVOID LockContext = NULL; // sanity check for LockMode = InterruptLock or StartIoLock
             PSTOR_ADDR_BTL8 stor_addr = (PSTOR_ADDR_BTL8)Parameters;
 
             for (vq_req_idx = 0; vq_req_idx < adaptExt->num_queues; vq_req_idx++)
             {
                 element = &adaptExt->processing_srbs[vq_req_idx];
-                LockContext = &adaptExt->dpc[vq_req_idx];
-                StorPortAcquireSpinLock(DeviceExtension, DpcLock, LockContext, &LockHandle);
+                StorPortAcquireSpinLock(DeviceExtension, DpcLock, &adaptExt->dpc[vq_req_idx], &LockHandle);
                 if (!IsListEmpty(&element->srb_list))
                 {
                     PLIST_ENTRY entry = element->srb_list.Flink;
@@ -1414,14 +1412,14 @@ VOID FORCEINLINE DispatchQueue(IN PVOID DeviceExtension, IN ULONG MessageId)
                          &adaptExt->dpc[MessageId - QUEUE_TO_MESSAGE(VIRTIO_SCSI_REQUEST_QUEUE_0)],
                          ULongToPtr(MessageId),
                          ULongToPtr(MessageId));
-        EXIT_FN();
-        return;
+    } else
+    {
+        ProcessBuffer(DeviceExtension, MessageId, TRUE);
     }
-    ProcessBuffer(DeviceExtension, MessageId, InterruptLock);
     EXIT_FN();
 }
 
-VOID ProcessBuffer(IN PVOID DeviceExtension, IN ULONG MessageId, IN STOR_SPINLOCK LockMode)
+VOID ProcessBuffer(IN PVOID DeviceExtension, IN ULONG MessageId, IN BOOLEAN DumpModeNoSync)
 {
     PVirtIOSCSICmd cmd;
     unsigned int len;
@@ -1433,7 +1431,6 @@ VOID ProcessBuffer(IN PVOID DeviceExtension, IN ULONG MessageId, IN STOR_SPINLOC
     PSRB_EXTENSION srbExt = NULL;
     PREQUEST_LIST element;
     ULONG vq_req_idx;
-    PVOID LockContext = NULL; // sanity check for LockMode = InterruptLock or StartIoLock
 
     ENTER_FN();
 
@@ -1448,12 +1445,9 @@ VOID ProcessBuffer(IN PVOID DeviceExtension, IN ULONG MessageId, IN STOR_SPINLOC
 
     vq = adaptExt->vq[QueueNumber];
 
-    if (LockMode == DpcLock)
-    {
-        LockContext = &adaptExt->dpc[vq_req_idx];
+    if (!DumpModeNoSync) {
+        StorPortAcquireSpinLock(DeviceExtension, DpcLock, &adaptExt->dpc[vq_req_idx], &LockHandle);
     }
-    StorPortAcquireSpinLock(DeviceExtension, LockMode, LockContext, &LockHandle);
-
     do
     {
         virtqueue_disable_cb(vq);
@@ -1488,7 +1482,9 @@ VOID ProcessBuffer(IN PVOID DeviceExtension, IN ULONG MessageId, IN STOR_SPINLOC
         }
     } while (!virtqueue_enable_cb(vq));
 
-    StorPortReleaseSpinLock(DeviceExtension, &LockHandle);
+    if (!DumpModeNoSync) {
+        StorPortReleaseSpinLock(DeviceExtension, &LockHandle);
+    }
 
     EXIT_FN();
 }
@@ -1499,7 +1495,7 @@ VOID VioScsiCompleteDpcRoutine(IN PSTOR_DPC Dpc, IN PVOID Context, IN PVOID Syst
 
     ENTER_FN();
     MessageId = PtrToUlong(SystemArgument1);
-    ProcessBuffer(Context, MessageId, DpcLock);
+    ProcessBuffer(Context, MessageId, FALSE);
     EXIT_FN();
 }
 
@@ -1510,7 +1506,6 @@ VOID CompletePendingRequestsOnReset(IN PVOID DeviceExtension)
     ULONG vq_req_idx;
     PREQUEST_LIST element;
     STOR_LOCK_HANDLE LockHandle = {0};
-    PVOID LockContext = NULL; // sanity check for LockMode = InterruptLock or StartIoLock
 
     adaptExt = (PADAPTER_EXTENSION)DeviceExtension;
 
@@ -1524,8 +1519,8 @@ VOID CompletePendingRequestsOnReset(IN PVOID DeviceExtension)
         {
             element = &adaptExt->processing_srbs[vq_req_idx];
             RhelDbgPrint(TRACE_LEVEL_FATAL, " queue %d cnt %d\n", vq_req_idx, element->srb_cnt);
-            LockContext = &adaptExt->dpc[vq_req_idx];
-            StorPortAcquireSpinLock(DeviceExtension, DpcLock, LockContext, &LockHandle);
+
+            StorPortAcquireSpinLock(DeviceExtension, DpcLock, &adaptExt->dpc[vq_req_idx], &LockHandle);
             while (!IsListEmpty(&element->srb_list))
             {
                 PLIST_ENTRY entry = RemoveHeadList(&element->srb_list);