diff options
Diffstat (limited to 'OvmfPkg/XenPvBlkDxe/BlockFront.c')
| -rw-r--r-- | OvmfPkg/XenPvBlkDxe/BlockFront.c | 647 |
1 files changed, 647 insertions, 0 deletions
diff --git a/OvmfPkg/XenPvBlkDxe/BlockFront.c b/OvmfPkg/XenPvBlkDxe/BlockFront.c new file mode 100644 index 0000000000..3c039e7add --- /dev/null +++ b/OvmfPkg/XenPvBlkDxe/BlockFront.c @@ -0,0 +1,647 @@ +/** @file
+ Minimal block driver for Mini-OS.
+
+ Copyright (c) 2007-2008 Samuel Thibault.
+ Copyright (C) 2014, Citrix Ltd.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+ 1. Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ SUCH DAMAGE.
+**/
+
+#include <Library/PrintLib.h>
+#include <Library/DebugLib.h>
+
+#include "BlockFront.h"
+
+#include <IndustryStandard/Xen/io/protocols.h>
+#include <IndustryStandard/Xen/io/xenbus.h>
+
+//
+// Header used for UINT32_MAX and UINT16_MAX
+//
+#include "inttypes.h"
+
+/**
+ Helper to read an integer from XenStore.
+
+ If the number overflows according to the range defined by UINT64,
+ then ASSERT().
+
+ @param This A pointer to a XENBUS_PROTOCOL instance.
+ @param Node The XenStore node to read from.
+ @param FromBackend Read frontend or backend value.
+ @param ValuePtr Where to put the value.
+
+ @retval XENSTORE_STATUS_SUCCESS If succefull, will update ValuePtr.
+ @return Any other return value indicate the error,
+ ValuePtr is not updated in this case.
+**/
+STATIC
+XENSTORE_STATUS
+XenBusReadUint64 (
+ IN XENBUS_PROTOCOL *This,
+ IN CONST CHAR8 *Node,
+ IN BOOLEAN FromBackend,
+ OUT UINT64 *ValuePtr
+ )
+{
+ XENSTORE_STATUS Status;
+ CHAR8 *Ptr;
+
+ if (!FromBackend) {
+ Status = This->XsRead (This, XST_NIL, Node, (VOID**)&Ptr);
+ } else {
+ Status = This->XsBackendRead (This, XST_NIL, Node, (VOID**)&Ptr);
+ }
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ return Status;
+ }
+ // AsciiStrDecimalToUint64 will ASSERT if Ptr overflow UINT64.
+ *ValuePtr = AsciiStrDecimalToUint64 (Ptr);
+ FreePool (Ptr);
+ return Status;
+}
+
+/**
+ Free an instance of XEN_BLOCK_FRONT_DEVICE.
+
+ @param Dev The instance to free.
+**/
+STATIC
+VOID
+XenPvBlockFree (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev
+ )
+{
+ XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
+
+ if (Dev->RingRef != 0) {
+ XenBusIo->GrantEndAccess (XenBusIo, Dev->RingRef);
+ }
+ if (Dev->Ring.sring != NULL) {
+ FreePages (Dev->Ring.sring, 1);
+ }
+ if (Dev->EventChannel != 0) {
+ XenBusIo->EventChannelClose (XenBusIo, Dev->EventChannel);
+ }
+ FreePool (Dev);
+}
+
+/**
+ Wait until until the backend has reached the ExpectedState.
+
+ @param Dev A XEN_BLOCK_FRONT_DEVICE instance.
+ @param ExpectedState The backend state expected.
+ @param LastStatePtr An optional pointer where to right the final state.
+
+ @return Return XENSTORE_STATUS_SUCCESS if the new backend state is ExpectedState
+ or return an error otherwise.
+**/
+STATIC
+XENSTORE_STATUS
+XenPvBlkWaitForBackendState (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev,
+ IN XenbusState ExpectedState,
+ OUT XenbusState *LastStatePtr OPTIONAL
+ )
+{
+ XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
+ XenbusState State;
+ UINT64 Value;
+ XENSTORE_STATUS Status = XENSTORE_STATUS_SUCCESS;
+
+ while (TRUE) {
+ Status = XenBusReadUint64 (XenBusIo, "state", TRUE, &Value);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ return Status;
+ }
+ if (Value > XenbusStateReconfigured) {
+ //
+ // Value is not a State value.
+ //
+ return XENSTORE_STATUS_EIO;
+ }
+ State = Value;
+ if (State == ExpectedState) {
+ break;
+ } else if (State > ExpectedState) {
+ Status = XENSTORE_STATUS_FAIL;
+ break;
+ }
+ DEBUG ((EFI_D_INFO,
+ "XenPvBlk: waiting backend state %d, current: %d\n",
+ ExpectedState, State));
+ XenBusIo->WaitForWatch (XenBusIo, Dev->StateWatchToken);
+ }
+
+ if (LastStatePtr != NULL) {
+ *LastStatePtr = State;
+ }
+
+ return Status;
+}
+
+EFI_STATUS
+XenPvBlockFrontInitialization (
+ IN XENBUS_PROTOCOL *XenBusIo,
+ IN CONST CHAR8 *NodeName,
+ OUT XEN_BLOCK_FRONT_DEVICE **DevPtr
+ )
+{
+ XENSTORE_TRANSACTION xbt;
+ CHAR8 *DeviceType;
+ blkif_sring_t *SharedRing;
+ XENSTORE_STATUS Status;
+ XEN_BLOCK_FRONT_DEVICE *Dev;
+ XenbusState State;
+ UINT64 Value;
+
+ ASSERT (NodeName != NULL);
+
+ Dev = AllocateZeroPool (sizeof (XEN_BLOCK_FRONT_DEVICE));
+ Dev->Signature = XEN_BLOCK_FRONT_SIGNATURE;
+ Dev->NodeName = NodeName;
+ Dev->XenBusIo = XenBusIo;
+ Dev->DeviceId = XenBusIo->DeviceId;
+
+ XenBusIo->XsRead (XenBusIo, XST_NIL, "device-type", (VOID**)&DeviceType);
+ if (AsciiStrCmp (DeviceType, "cdrom") == 0) {
+ Dev->MediaInfo.CdRom = TRUE;
+ } else {
+ Dev->MediaInfo.CdRom = FALSE;
+ }
+ FreePool (DeviceType);
+
+ Status = XenBusReadUint64 (XenBusIo, "backend-id", FALSE, &Value);
+ if (Status != XENSTORE_STATUS_SUCCESS || Value > UINT16_MAX) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to get backend-id (%d)\n",
+ Status));
+ goto Error;
+ }
+ Dev->DomainId = Value;
+ XenBusIo->EventChannelAllocate (XenBusIo, Dev->DomainId, &Dev->EventChannel);
+
+ SharedRing = (blkif_sring_t*) AllocatePages (1);
+ SHARED_RING_INIT (SharedRing);
+ FRONT_RING_INIT (&Dev->Ring, SharedRing, EFI_PAGE_SIZE);
+ XenBusIo->GrantAccess (XenBusIo,
+ Dev->DomainId,
+ (INTN) SharedRing >> EFI_PAGE_SHIFT,
+ FALSE,
+ &Dev->RingRef);
+
+Again:
+ Status = XenBusIo->XsTransactionStart (XenBusIo, &xbt);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_WARN, "XenPvBlk: Failed to start transaction, %d\n", Status));
+ goto Error;
+ }
+
+ Status = XenBusIo->XsPrintf (XenBusIo, xbt, NodeName, "ring-ref", "%d",
+ Dev->RingRef);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to write ring-ref.\n"));
+ goto AbortTransaction;
+ }
+ Status = XenBusIo->XsPrintf (XenBusIo, xbt, NodeName,
+ "event-channel", "%d", Dev->EventChannel);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to write event-channel.\n"));
+ goto AbortTransaction;
+ }
+ Status = XenBusIo->XsPrintf (XenBusIo, xbt, NodeName,
+ "protocol", "%a", XEN_IO_PROTO_ABI_NATIVE);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to write protocol.\n"));
+ goto AbortTransaction;
+ }
+
+ Status = XenBusIo->SetState (XenBusIo, xbt, XenbusStateConnected);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to switch state.\n"));
+ goto AbortTransaction;
+ }
+
+ Status = XenBusIo->XsTransactionEnd (XenBusIo, xbt, FALSE);
+ if (Status == XENSTORE_STATUS_EAGAIN) {
+ goto Again;
+ }
+
+ XenBusIo->RegisterWatchBackend (XenBusIo, "state", &Dev->StateWatchToken);
+
+ //
+ // Waiting for backend
+ //
+ Status = XenPvBlkWaitForBackendState (Dev, XenbusStateConnected, &State);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: backend for %a/%d not available, rc=%d state=%d\n",
+ XenBusIo->Type, XenBusIo->DeviceId, Status, State));
+ goto Error2;
+ }
+
+ Status = XenBusReadUint64 (XenBusIo, "info", TRUE, &Value);
+ if (Status != XENSTORE_STATUS_SUCCESS || Value > UINT32_MAX) {
+ goto Error2;
+ }
+ Dev->MediaInfo.VDiskInfo = Value;
+ if (Dev->MediaInfo.VDiskInfo & VDISK_READONLY) {
+ Dev->MediaInfo.ReadWrite = FALSE;
+ } else {
+ Dev->MediaInfo.ReadWrite = TRUE;
+ }
+
+ Status = XenBusReadUint64 (XenBusIo, "sectors", TRUE, &Dev->MediaInfo.Sectors);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ goto Error2;
+ }
+
+ Status = XenBusReadUint64 (XenBusIo, "sector-size", TRUE, &Value);
+ if (Status != XENSTORE_STATUS_SUCCESS || Value > UINT32_MAX) {
+ goto Error2;
+ }
+ if (Value % 512 != 0) {
+ //
+ // This is not supported by the driver.
+ //
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: Unsupported sector-size value %d, "
+ "it must be a multiple of 512\n", Value));
+ goto Error2;
+ }
+ Dev->MediaInfo.SectorSize = Value;
+
+ // Default value
+ Value = 0;
+ XenBusReadUint64 (XenBusIo, "feature-barrier", TRUE, &Value);
+ if (Value == 1) {
+ Dev->MediaInfo.FeatureBarrier = TRUE;
+ } else {
+ Dev->MediaInfo.FeatureBarrier = FALSE;
+ }
+
+ // Default value
+ Value = 0;
+ XenBusReadUint64 (XenBusIo, "feature-flush-cache", TRUE, &Value);
+ if (Value == 1) {
+ Dev->MediaInfo.FeatureFlushCache = TRUE;
+ } else {
+ Dev->MediaInfo.FeatureFlushCache = FALSE;
+ }
+
+ DEBUG ((EFI_D_INFO, "XenPvBlk: New disk with %ld sectors of %d bytes\n",
+ Dev->MediaInfo.Sectors, Dev->MediaInfo.SectorSize));
+
+ *DevPtr = Dev;
+ return EFI_SUCCESS;
+
+Error2:
+ XenBusIo->UnregisterWatch (XenBusIo, Dev->StateWatchToken);
+ XenBusIo->XsRemove (XenBusIo, XST_NIL, "ring-ref");
+ XenBusIo->XsRemove (XenBusIo, XST_NIL, "event-channel");
+ XenBusIo->XsRemove (XenBusIo, XST_NIL, "protocol");
+ goto Error;
+AbortTransaction:
+ XenBusIo->XsTransactionEnd (XenBusIo, xbt, TRUE);
+Error:
+ XenPvBlockFree (Dev);
+ return EFI_DEVICE_ERROR;
+}
+
+VOID
+XenPvBlockFrontShutdown (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev
+ )
+{
+ XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
+ XENSTORE_STATUS Status;
+ UINT64 Value;
+
+ XenPvBlockSync (Dev);
+
+ Status = XenBusIo->SetState (XenBusIo, XST_NIL, XenbusStateClosing);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: error while changing state to Closing: %d\n",
+ Status));
+ goto Close;
+ }
+
+ Status = XenPvBlkWaitForBackendState (Dev, XenbusStateClosing, NULL);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: error while waiting for closing backend state: %d\n",
+ Status));
+ goto Close;
+ }
+
+ Status = XenBusIo->SetState (XenBusIo, XST_NIL, XenbusStateClosed);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: error while changing state to Closed: %d\n",
+ Status));
+ goto Close;
+ }
+
+ Status = XenPvBlkWaitForBackendState (Dev, XenbusStateClosed, NULL);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: error while waiting for closed backend state: %d\n",
+ Status));
+ goto Close;
+ }
+
+ Status = XenBusIo->SetState (XenBusIo, XST_NIL, XenbusStateInitialising);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: error while changing state to initialising: %d\n",
+ Status));
+ goto Close;
+ }
+
+ while (TRUE) {
+ Status = XenBusReadUint64 (XenBusIo, "state", TRUE, &Value);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: error while waiting for new backend state: %d\n",
+ Status));
+ goto Close;
+ }
+ if (Value <= XenbusStateInitWait || Value >= XenbusStateClosed) {
+ break;
+ }
+ DEBUG ((EFI_D_INFO,
+ "XenPvBlk: waiting backend state %d, current: %d\n",
+ XenbusStateInitWait, Value));
+ XenBusIo->WaitForWatch (XenBusIo, Dev->StateWatchToken);
+ }
+
+Close:
+ XenBusIo->UnregisterWatch (XenBusIo, Dev->StateWatchToken);
+ XenBusIo->XsRemove (XenBusIo, XST_NIL, "ring-ref");
+ XenBusIo->XsRemove (XenBusIo, XST_NIL, "event-channel");
+ XenBusIo->XsRemove (XenBusIo, XST_NIL, "protocol");
+
+ XenPvBlockFree (Dev);
+}
+
+STATIC
+VOID
+XenPvBlockWaitSlot (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev
+ )
+{
+ /* Wait for a slot */
+ if (RING_FULL (&Dev->Ring)) {
+ while (TRUE) {
+ XenPvBlockAsyncIoPoll (Dev);
+ if (!RING_FULL (&Dev->Ring)) {
+ break;
+ }
+ /* Really no slot, could wait for an event on Dev->EventChannel. */
+ }
+ }
+}
+
+VOID
+XenPvBlockAsyncIo (
+ IN OUT XEN_BLOCK_FRONT_IO *IoData,
+ IN BOOLEAN IsWrite
+ )
+{
+ XEN_BLOCK_FRONT_DEVICE *Dev = IoData->Dev;
+ XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
+ blkif_request_t *Request;
+ RING_IDX RingIndex;
+ BOOLEAN Notify;
+ INT32 NumSegments, Index;
+ UINTN Start, End;
+
+ // Can't io at non-sector-aligned location
+ ASSERT(!(IoData->Sector & ((Dev->MediaInfo.SectorSize / 512) - 1)));
+ // Can't io non-sector-sized amounts
+ ASSERT(!(IoData->Size & (Dev->MediaInfo.SectorSize - 1)));
+ // Can't io non-sector-aligned buffer
+ ASSERT(!((UINTN) IoData->Buffer & (Dev->MediaInfo.SectorSize - 1)));
+
+ Start = (UINTN) IoData->Buffer & ~EFI_PAGE_MASK;
+ End = ((UINTN) IoData->Buffer + IoData->Size + EFI_PAGE_SIZE - 1) & ~EFI_PAGE_MASK;
+ IoData->NumRef = NumSegments = (End - Start) / EFI_PAGE_SIZE;
+
+ ASSERT (NumSegments <= BLKIF_MAX_SEGMENTS_PER_REQUEST);
+
+ XenPvBlockWaitSlot (Dev);
+ RingIndex = Dev->Ring.req_prod_pvt;
+ Request = RING_GET_REQUEST (&Dev->Ring, RingIndex);
+
+ Request->operation = IsWrite ? BLKIF_OP_WRITE : BLKIF_OP_READ;
+ Request->nr_segments = NumSegments;
+ Request->handle = Dev->DeviceId;
+ Request->id = (UINTN) IoData;
+ Request->sector_number = IoData->Sector;
+
+ for (Index = 0; Index < NumSegments; Index++) {
+ Request->seg[Index].first_sect = 0;
+ Request->seg[Index].last_sect = EFI_PAGE_SIZE / 512 - 1;
+ }
+ Request->seg[0].first_sect = ((UINTN) IoData->Buffer & EFI_PAGE_MASK) / 512;
+ Request->seg[NumSegments - 1].last_sect =
+ (((UINTN) IoData->Buffer + IoData->Size - 1) & EFI_PAGE_MASK) / 512;
+ for (Index = 0; Index < NumSegments; Index++) {
+ UINTN Data = Start + Index * EFI_PAGE_SIZE;
+ XenBusIo->GrantAccess (XenBusIo, Dev->DomainId,
+ Data >> EFI_PAGE_SHIFT, IsWrite,
+ &Request->seg[Index].gref);
+ IoData->GrantRef[Index] = Request->seg[Index].gref;
+ }
+
+ Dev->Ring.req_prod_pvt = RingIndex + 1;
+
+ MemoryFence ();
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY (&Dev->Ring, Notify);
+
+ if (Notify) {
+ UINT32 ReturnCode;
+ ReturnCode = XenBusIo->EventChannelNotify (XenBusIo, Dev->EventChannel);
+ if (ReturnCode != 0) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: Unexpected return value from EventChannelNotify: %d\n",
+ ReturnCode));
+ }
+ }
+}
+
+EFI_STATUS
+XenPvBlockIo (
+ IN OUT XEN_BLOCK_FRONT_IO *IoData,
+ IN BOOLEAN IsWrite
+ )
+{
+ //
+ // Status value that correspond to an IO in progress.
+ //
+ IoData->Status = EFI_ALREADY_STARTED;
+ XenPvBlockAsyncIo (IoData, IsWrite);
+
+ while (IoData->Status == EFI_ALREADY_STARTED) {
+ XenPvBlockAsyncIoPoll (IoData->Dev);
+ }
+
+ return IoData->Status;
+}
+
+STATIC
+VOID
+XenPvBlockPushOperation (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev,
+ IN UINT8 Operation,
+ IN UINT64 Id
+ )
+{
+ INT32 Index;
+ blkif_request_t *Request;
+ BOOLEAN Notify;
+
+ XenPvBlockWaitSlot (Dev);
+ Index = Dev->Ring.req_prod_pvt;
+ Request = RING_GET_REQUEST(&Dev->Ring, Index);
+ Request->operation = Operation;
+ Request->nr_segments = 0;
+ Request->handle = Dev->DeviceId;
+ Request->id = Id;
+ /* Not needed anyway, but the backend will check it */
+ Request->sector_number = 0;
+ Dev->Ring.req_prod_pvt = Index + 1;
+ MemoryFence ();
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY (&Dev->Ring, Notify);
+ if (Notify) {
+ XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
+ UINT32 ReturnCode;
+ ReturnCode = XenBusIo->EventChannelNotify (XenBusIo, Dev->EventChannel);
+ if (ReturnCode != 0) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: Unexpected return value from EventChannelNotify: %d\n",
+ ReturnCode));
+ }
+ }
+}
+
+VOID
+XenPvBlockSync (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev
+ )
+{
+ if (Dev->MediaInfo.ReadWrite) {
+ if (Dev->MediaInfo.FeatureBarrier) {
+ XenPvBlockPushOperation (Dev, BLKIF_OP_WRITE_BARRIER, 0);
+ }
+
+ if (Dev->MediaInfo.FeatureFlushCache) {
+ XenPvBlockPushOperation (Dev, BLKIF_OP_FLUSH_DISKCACHE, 0);
+ }
+ }
+
+ /* Note: This won't finish if another thread enqueues requests. */
+ while (TRUE) {
+ XenPvBlockAsyncIoPoll (Dev);
+ if (RING_FREE_REQUESTS (&Dev->Ring) == RING_SIZE (&Dev->Ring)) {
+ break;
+ }
+ }
+}
+
+VOID
+XenPvBlockAsyncIoPoll (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev
+ )
+{
+ RING_IDX ProducerIndex, ConsumerIndex;
+ blkif_response_t *Response;
+ INT32 More;
+
+ do {
+ ProducerIndex = Dev->Ring.sring->rsp_prod;
+ /* Ensure we see queued responses up to 'ProducerIndex'. */
+ MemoryFence ();
+ ConsumerIndex = Dev->Ring.rsp_cons;
+
+ while (ConsumerIndex != ProducerIndex) {
+ XEN_BLOCK_FRONT_IO *IoData = NULL;
+ INT16 Status;
+
+ Response = RING_GET_RESPONSE (&Dev->Ring, ConsumerIndex);
+
+ IoData = (VOID *) (UINTN) Response->id;
+ Status = Response->status;
+
+ switch (Response->operation) {
+ case BLKIF_OP_READ:
+ case BLKIF_OP_WRITE:
+ {
+ INT32 Index;
+
+ if (Status != BLKIF_RSP_OKAY) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: "
+ "%a error %d on %a at sector %p, num bytes %p\n",
+ Response->operation == BLKIF_OP_READ ? "read" : "write",
+ Status, IoData->Dev->NodeName,
+ IoData->Sector,
+ IoData->Size));
+ }
+
+ for (Index = 0; Index < IoData->NumRef; Index++) {
+ Dev->XenBusIo->GrantEndAccess (Dev->XenBusIo, IoData->GrantRef[Index]);
+ }
+
+ break;
+ }
+
+ case BLKIF_OP_WRITE_BARRIER:
+ if (Status != BLKIF_RSP_OKAY) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: write barrier error %d\n", Status));
+ }
+ break;
+ case BLKIF_OP_FLUSH_DISKCACHE:
+ if (Status != BLKIF_RSP_OKAY) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: flush error %d\n", Status));
+ }
+ break;
+
+ default:
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: unrecognized block operation %d response (status %d)\n",
+ Response->operation, Status));
+ break;
+ }
+
+ Dev->Ring.rsp_cons = ++ConsumerIndex;
+ if (IoData != NULL) {
+ IoData->Status = Status ? EFI_DEVICE_ERROR : EFI_SUCCESS;
+ }
+ if (Dev->Ring.rsp_cons != ConsumerIndex) {
+ /* We reentered, we must not continue here */
+ break;
+ }
+ }
+
+ RING_FINAL_CHECK_FOR_RESPONSES (&Dev->Ring, More);
+ } while (More != 0);
+}
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