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authorjljusten <jljusten@6f19259b-4bc3-4df7-8a09-765794883524>2012-10-12 18:54:35 +0000
committerjljusten <jljusten@6f19259b-4bc3-4df7-8a09-765794883524>2012-10-12 18:54:35 +0000
commite371e7e545b266ce4ae8ff76da6c98616214599f (patch)
treea84a0cfda267c9077772bc8ec20fcf8cb65741da /OvmfPkg/VirtioBlkDxe
parent7fcacd6c92616fd993a5befd93bcc9cad2610c90 (diff)
downloadedk2-platforms-e371e7e545b266ce4ae8ff76da6c98616214599f.tar.xz
OvmfPkg: librarize reusable bits from VirtioBlkDxe's SynchronousRequest()
new VirtioLib functions: - VirtioPrepare(): prepare for appending descriptors - VirtioFlush(): submit descriptor chain and await host answer Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Jordan Justen <jordan.l.justen@intel.com> git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13844 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'OvmfPkg/VirtioBlkDxe')
-rw-r--r--OvmfPkg/VirtioBlkDxe/VirtioBlk.c58
1 files changed, 8 insertions, 50 deletions
diff --git a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
index ce38ff7093..44a05cfb5f 100644
--- a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
+++ b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
@@ -248,9 +248,7 @@ SynchronousRequest (
UINT32 BlockSize;
volatile VIRTIO_BLK_REQ Request;
volatile UINT8 HostStatus;
- UINT16 FirstAvailIdx;
- UINT16 NextAvailIdx;
- UINTN PollPeriodUsecs;
+ DESC_INDICES Indices;
BlockSize = Dev->BlockIoMedia.BlockSize;
@@ -275,11 +273,7 @@ SynchronousRequest (
Request.IoPrio = 0;
Request.Sector = Lba * (BlockSize / 512);
- //
- // Prepare for virtio-0.9.5, 2.4.2 Receiving Used Buffers From the Device.
- // We're going to poll the answer, the host should not send an interrupt.
- //
- *Dev->Ring.Avail.Flags = (UINT16) VRING_AVAIL_F_NO_INTERRUPT;
+ VirtioPrepare (&Dev->Ring, &Indices);
//
// preset a host status for ourselves that we do not accept as success
@@ -293,16 +287,10 @@ SynchronousRequest (
ASSERT (Dev->Ring.QueueSize >= 3);
//
- // Implement virtio-0.9.5, 2.4.1 Supplying Buffers to the Device.
- //
- FirstAvailIdx = *Dev->Ring.Avail.Idx;
- NextAvailIdx = FirstAvailIdx;
-
- //
// virtio-blk header in first desc
//
VirtioAppendDesc (&Dev->Ring, (UINTN) &Request, sizeof Request,
- VRING_DESC_F_NEXT, FirstAvailIdx, &NextAvailIdx);
+ VRING_DESC_F_NEXT, &Indices);
//
// data buffer for read/write in second desc
@@ -323,50 +311,20 @@ SynchronousRequest (
//
VirtioAppendDesc (&Dev->Ring, (UINTN) Buffer, (UINT32) BufferSize,
VRING_DESC_F_NEXT | (RequestIsWrite ? 0 : VRING_DESC_F_WRITE),
- FirstAvailIdx, &NextAvailIdx);
+ &Indices);
}
//
// host status in last (second or third) desc
//
VirtioAppendDesc (&Dev->Ring, (UINTN) &HostStatus, sizeof HostStatus,
- VRING_DESC_F_WRITE, FirstAvailIdx, &NextAvailIdx);
+ VRING_DESC_F_WRITE, &Indices);
//
- // virtio-0.9.5, 2.4.1.3 Updating the Index Field
+ // virtio-blk's only virtqueue is #0, called "requestq" (see Appendix D).
//
- MemoryFence();
- *Dev->Ring.Avail.Idx = NextAvailIdx;
-
- //
- // virtio-0.9.5, 2.4.1.4 Notifying the Device -- gratuitous notifications are
- // OK. virtio-blk's only virtqueue is #0, called "requestq" (see Appendix D).
- //
- MemoryFence();
- if (EFI_ERROR (VIRTIO_CFG_WRITE (Dev, Generic.VhdrQueueNotify, 0))) {
- return EFI_DEVICE_ERROR;
- }
-
- //
- // virtio-0.9.5, 2.4.2 Receiving Used Buffers From the Device
- // Wait until the host processes and acknowledges our 3-part descriptor
- // chain. The condition we use for polling is greatly simplified and relies
- // on synchronous, the lock-step progress.
- //
- // Keep slowing down until we reach a poll period of slightly above 1 ms.
- //
- PollPeriodUsecs = 1;
- MemoryFence();
- while (*Dev->Ring.Used.Idx != NextAvailIdx) {
- gBS->Stall (PollPeriodUsecs); // calls AcpiTimerLib::MicroSecondDelay
-
- if (PollPeriodUsecs < 1024) {
- PollPeriodUsecs *= 2;
- }
- MemoryFence();
- }
-
- if (HostStatus == VIRTIO_BLK_S_OK) {
+ if (VirtioFlush (Dev->PciIo, 0, &Dev->Ring, &Indices) == EFI_SUCCESS &&
+ HostStatus == VIRTIO_BLK_S_OK) {
return EFI_SUCCESS;
}