[PATCH xenbus 01/12] Introduce a new XENBUS_VIRQ structure and new functions...

[Paul Durrant <paul@xxxxxxx>]

From: Paul Durrant <pdurrant@xxxxxxxxxx>

... for creation/destruction of VIRQ event channels.

Currently XENBUS only opens a DEBUG_VIRQ channel, which is used to trigger
a dump of diagnostics information when sent by the 'q' key handler in Xen.

Subsequent patches will open other VIRQ channels and hence this patch lays
the groundwork for those modifications.

Signed-off-by: Paul Durrant <pdurrant@xxxxxxxxxx>
---
 src/common/names.h |  22 ++++++
 src/xenbus/fdo.c   | 192 ++++++++++++++++++++++++++++++++++-----------
 2 files changed, 169 insertions(+), 45 deletions(-)

diff --git a/src/common/names.h b/src/common/names.h
index 90636bb86d74..84267d18fe5e 100644
--- a/src/common/names.h
+++ b/src/common/names.h
@@ -33,6 +33,7 @@
 #define _COMMON_NAMES_H_
 
 #include <ntddk.h>
+#include <xen.h>
 
 static FORCEINLINE const CHAR *
 PowerStateTypeName(
@@ -472,4 +473,25 @@ ProcessorChangeName(
 #undef _PROCESSOR_CHANGE_NAME
 }
 
+static FORCEINLINE const CHAR *
+VirqName(
+    IN  ULONG   Type
+    )
+{
+#define _VIRQ_NAME(_Type) \
+    case VIRQ_ ## _Type:  \
+        return #_Type;
+
+    switch (Type) {
+    _VIRQ_NAME(DEBUG);
+    _VIRQ_NAME(TIMER);
+    default:
+        break;
+    }
+
+    return "UNKNOWN";
+
+#undef _VIRQ_NAME
+}
+
 #endif // _COMMON_NAMES_H_
diff --git a/src/xenbus/fdo.c b/src/xenbus/fdo.c
index 27837b293587..cdcfc85d6090 100644
--- a/src/xenbus/fdo.c
+++ b/src/xenbus/fdo.c
@@ -80,6 +80,13 @@ struct _XENBUS_INTERRUPT {
     PVOID               Argument;
 };
 
+typedef struct _XENBUS_VIRQ {
+    PXENBUS_FDO             Fdo;
+    LIST_ENTRY              ListEntry;
+    ULONG                   Type;
+    PXENBUS_EVTCHN_CHANNEL  Channel;
+} XENBUS_VIRQ, *PXENBUS_VIRQ;
+
 struct _XENBUS_FDO {
     PXENBUS_DX                      Dx;
     PDEVICE_OBJECT                  LowerDeviceObject;
@@ -143,7 +150,7 @@ struct _XENBUS_FDO {
     PXENBUS_RANGE_SET               RangeSet;
     LIST_ENTRY                      InterruptList;
 
-    PXENBUS_EVTCHN_CHANNEL          Channel;
+    LIST_ENTRY                      VirqList;
     PXENBUS_SUSPEND_CALLBACK        SuspendCallbackLate;
     PLOG_DISPOSITION                LogDisposition;
 };
@@ -2491,27 +2498,6 @@ FdoDestroyInterrupt(
     RtlZeroMemory(&Fdo->InterruptList, sizeof (LIST_ENTRY));
 }
 
-static
-_Function_class_(KSERVICE_ROUTINE)
-_IRQL_requires_(HIGH_LEVEL)
-_IRQL_requires_same_
-BOOLEAN
-FdoEvtchnCallback(
-    IN  PKINTERRUPT         InterruptObject,
-    IN  PVOID               Argument
-    )
-{
-    PXENBUS_FDO             Fdo = Argument;
-
-    UNREFERENCED_PARAMETER(InterruptObject);
-
-    ASSERT(Fdo != NULL);
-
-    XENBUS_DEBUG(Trigger, &Fdo->DebugInterface, NULL);
-
-    return TRUE;
-}
-
 static FORCEINLINE BOOLEAN
 __FdoMatchDistribution(
     IN  PXENBUS_FDO Fdo,
@@ -2767,6 +2753,141 @@ FdoOutputBuffer(
                           (ULONG)(Cursor - FdoOutBuffer));
 }
 
+static
+_Function_class_(KSERVICE_ROUTINE)
+_IRQL_requires_(HIGH_LEVEL)
+_IRQL_requires_same_
+BOOLEAN
+FdoVirqCallback(
+    IN  PKINTERRUPT InterruptObject,
+    IN  PVOID       Argument
+    )
+{
+    PXENBUS_VIRQ    Virq = Argument;
+    PXENBUS_FDO     Fdo;
+
+    UNREFERENCED_PARAMETER(InterruptObject);
+
+    ASSERT(Virq != NULL);
+    Fdo = Virq->Fdo;
+
+    ASSERT3U(Virq->Type, ==, VIRQ_DEBUG);
+    XENBUS_DEBUG(Trigger, &Fdo->DebugInterface, NULL);
+
+    return TRUE;
+}
+
+static FORCEINLINE VOID
+__FdoVirqDestroy(
+    IN  PXENBUS_VIRQ    Virq
+    )
+{
+    PXENBUS_FDO         Fdo = Virq->Fdo;
+
+    Info("%s\n", VirqName(Virq->Type));
+
+    XENBUS_EVTCHN(Close,
+                  &Fdo->EvtchnInterface,
+                  Virq->Channel);
+
+    __FdoFree(Virq);
+}
+
+static FORCEINLINE NTSTATUS
+__FdoVirqCreate(
+    IN  PXENBUS_FDO     Fdo,
+    IN  ULONG           Type,
+    OUT PXENBUS_VIRQ    *Virq
+    )
+{
+    NTSTATUS            status;
+
+    *Virq = __FdoAllocate(sizeof (XENBUS_VIRQ));
+
+    status = STATUS_NO_MEMORY;
+    if (*Virq == NULL)
+        goto fail1;
+
+    (*Virq)->Fdo = Fdo;
+    (*Virq)->Type = Type;
+    (*Virq)->Channel = XENBUS_EVTCHN(Open,
+                                     &Fdo->EvtchnInterface,
+                                     XENBUS_EVTCHN_TYPE_VIRQ,
+                                     FdoVirqCallback,
+                                     *Virq,
+                                     Type);
+
+    status = STATUS_UNSUCCESSFUL;
+    if ((*Virq)->Channel == NULL)
+        goto fail2;
+
+    (VOID) XENBUS_EVTCHN(Unmask,
+                         &Fdo->EvtchnInterface,
+                         (*Virq)->Channel,
+                         FALSE,
+                         TRUE);
+
+    Info("%s\n", VirqName((*Virq)->Type));
+
+    return STATUS_SUCCESS;
+
+fail2:
+    Error("fail2\n");
+
+    __FdoFree(*Virq);
+
+fail1:
+    Error("fail1 (%08x)\n", status);
+
+    return status;
+}
+
+static VOID
+FdoVirqTeardown(
+    IN  PXENBUS_FDO Fdo
+    )
+{
+    while (!IsListEmpty(&Fdo->VirqList)) {
+        PLIST_ENTRY     ListEntry;
+        PXENBUS_VIRQ    Virq;
+
+        ListEntry = RemoveHeadList(&Fdo->VirqList);
+        ASSERT(ListEntry != &Fdo->VirqList);
+
+        RtlZeroMemory(ListEntry, sizeof (LIST_ENTRY));
+
+        Virq = CONTAINING_RECORD(ListEntry, XENBUS_VIRQ, ListEntry);
+
+        __FdoVirqDestroy(Virq);
+    }
+
+    RtlZeroMemory(&Fdo->VirqList, sizeof (LIST_ENTRY));
+}
+
+static NTSTATUS
+FdoVirqInitialize(
+    IN  PXENBUS_FDO Fdo
+    )
+{
+    PXENBUS_VIRQ    Virq;
+    NTSTATUS        status;
+
+    InitializeListHead(&Fdo->VirqList);
+
+    status = __FdoVirqCreate(Fdo, VIRQ_DEBUG, &Virq);
+    if (!NT_SUCCESS(status))
+        goto fail1;
+
+    InsertTailList(&Fdo->VirqList, &Virq->ListEntry);
+
+    return STATUS_SUCCESS;
+
+fail1:
+    Error("fail1 (%08x)\n", status);
+
+    return status;
+}
+
 static FORCEINLINE NTSTATUS
 __FdoD3ToD0(
     IN  PXENBUS_FDO Fdo
@@ -2780,23 +2901,10 @@ __FdoD3ToD0(
 
     (VOID) FdoSetDistribution(Fdo);
 
-    Fdo->Channel = XENBUS_EVTCHN(Open,
-                                 &Fdo->EvtchnInterface,
-                                 XENBUS_EVTCHN_TYPE_VIRQ,
-                                 FdoEvtchnCallback,
-                                 Fdo,
-                                 VIRQ_DEBUG);
-
-    status = STATUS_UNSUCCESSFUL;
-    if (Fdo->Channel == NULL)
+    status = FdoVirqInitialize(Fdo);
+    if (!NT_SUCCESS(status))
         goto fail1;
 
-    (VOID) XENBUS_EVTCHN(Unmask,
-                         &Fdo->EvtchnInterface,
-                         Fdo->Channel,
-                         FALSE,
-                         TRUE);
-
     status = LogAddDisposition(DriverGetConsoleLogLevel(),
                                FdoOutputBuffer,
                                Fdo,
@@ -2880,10 +2988,7 @@ fail2:
     LogRemoveDisposition(Fdo->LogDisposition);
     Fdo->LogDisposition = NULL;
 
-    XENBUS_EVTCHN(Close,
-                  &Fdo->EvtchnInterface,
-                  Fdo->Channel);
-    Fdo->Channel = NULL;
+    FdoVirqTeardown(Fdo);
 
 fail1:
     Error("fail1 (%08x)\n", status);
@@ -2932,10 +3037,7 @@ __FdoD0ToD3(
     LogRemoveDisposition(Fdo->LogDisposition);
     Fdo->LogDisposition = NULL;
 
-    XENBUS_EVTCHN(Close,
-                  &Fdo->EvtchnInterface,
-                  Fdo->Channel);
-    Fdo->Channel = NULL;
+    FdoVirqTeardown(Fdo);
 
     FdoClearDistribution(Fdo);
 
-- 
2.17.1