mirror of https://github.com/acidanthera/audk.git
320 lines
9.7 KiB
C
320 lines
9.7 KiB
C
/** @file
|
|
|
|
Utility functions used by virtio device drivers.
|
|
|
|
Copyright (C) 2012, Red Hat, Inc.
|
|
Portion of Copyright (C) 2013, ARM Ltd.
|
|
|
|
This program and the accompanying materials are licensed and made available
|
|
under the terms and conditions of the BSD License which accompanies this
|
|
distribution. The full text of the license may be found at
|
|
http://opensource.org/licenses/bsd-license.php
|
|
|
|
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
|
|
WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
|
|
|
|
**/
|
|
|
|
#include <Library/BaseLib.h>
|
|
#include <Library/BaseMemoryLib.h>
|
|
#include <Library/DebugLib.h>
|
|
#include <Library/MemoryAllocationLib.h>
|
|
#include <Library/UefiBootServicesTableLib.h>
|
|
|
|
#include <Library/VirtioLib.h>
|
|
|
|
|
|
/**
|
|
|
|
Configure a virtio ring.
|
|
|
|
This function sets up internal storage (the guest-host communication area)
|
|
and lays out several "navigation" (ie. no-ownership) pointers to parts of
|
|
that storage.
|
|
|
|
Relevant sections from the virtio-0.9.5 spec:
|
|
- 1.1 Virtqueues,
|
|
- 2.3 Virtqueue Configuration.
|
|
|
|
@param[in] The number of descriptors to allocate for the
|
|
virtio ring, as requested by the host.
|
|
|
|
@param[out] Ring The virtio ring to set up.
|
|
|
|
@retval EFI_OUT_OF_RESOURCES AllocatePages() failed to allocate contiguous
|
|
pages for the requested QueueSize. Fields of
|
|
Ring have indeterminate value.
|
|
|
|
@retval EFI_SUCCESS Allocation and setup successful. Ring->Base
|
|
(and nothing else) is responsible for
|
|
deallocation.
|
|
|
|
**/
|
|
EFI_STATUS
|
|
EFIAPI
|
|
VirtioRingInit (
|
|
IN UINT16 QueueSize,
|
|
OUT VRING *Ring
|
|
)
|
|
{
|
|
UINTN RingSize;
|
|
volatile UINT8 *RingPagesPtr;
|
|
|
|
RingSize = ALIGN_VALUE (
|
|
sizeof *Ring->Desc * QueueSize +
|
|
sizeof *Ring->Avail.Flags +
|
|
sizeof *Ring->Avail.Idx +
|
|
sizeof *Ring->Avail.Ring * QueueSize +
|
|
sizeof *Ring->Avail.UsedEvent,
|
|
EFI_PAGE_SIZE);
|
|
|
|
RingSize += ALIGN_VALUE (
|
|
sizeof *Ring->Used.Flags +
|
|
sizeof *Ring->Used.Idx +
|
|
sizeof *Ring->Used.UsedElem * QueueSize +
|
|
sizeof *Ring->Used.AvailEvent,
|
|
EFI_PAGE_SIZE);
|
|
|
|
Ring->NumPages = EFI_SIZE_TO_PAGES (RingSize);
|
|
Ring->Base = AllocatePages (Ring->NumPages);
|
|
if (Ring->Base == NULL) {
|
|
return EFI_OUT_OF_RESOURCES;
|
|
}
|
|
SetMem (Ring->Base, RingSize, 0x00);
|
|
RingPagesPtr = Ring->Base;
|
|
|
|
Ring->Desc = (volatile VOID *) RingPagesPtr;
|
|
RingPagesPtr += sizeof *Ring->Desc * QueueSize;
|
|
|
|
Ring->Avail.Flags = (volatile VOID *) RingPagesPtr;
|
|
RingPagesPtr += sizeof *Ring->Avail.Flags;
|
|
|
|
Ring->Avail.Idx = (volatile VOID *) RingPagesPtr;
|
|
RingPagesPtr += sizeof *Ring->Avail.Idx;
|
|
|
|
Ring->Avail.Ring = (volatile VOID *) RingPagesPtr;
|
|
RingPagesPtr += sizeof *Ring->Avail.Ring * QueueSize;
|
|
|
|
Ring->Avail.UsedEvent = (volatile VOID *) RingPagesPtr;
|
|
RingPagesPtr += sizeof *Ring->Avail.UsedEvent;
|
|
|
|
RingPagesPtr = (volatile UINT8 *) Ring->Base +
|
|
ALIGN_VALUE (RingPagesPtr - (volatile UINT8 *) Ring->Base,
|
|
EFI_PAGE_SIZE);
|
|
|
|
Ring->Used.Flags = (volatile VOID *) RingPagesPtr;
|
|
RingPagesPtr += sizeof *Ring->Used.Flags;
|
|
|
|
Ring->Used.Idx = (volatile VOID *) RingPagesPtr;
|
|
RingPagesPtr += sizeof *Ring->Used.Idx;
|
|
|
|
Ring->Used.UsedElem = (volatile VOID *) RingPagesPtr;
|
|
RingPagesPtr += sizeof *Ring->Used.UsedElem * QueueSize;
|
|
|
|
Ring->Used.AvailEvent = (volatile VOID *) RingPagesPtr;
|
|
RingPagesPtr += sizeof *Ring->Used.AvailEvent;
|
|
|
|
Ring->QueueSize = QueueSize;
|
|
return EFI_SUCCESS;
|
|
}
|
|
|
|
|
|
/**
|
|
|
|
Tear down the internal resources of a configured virtio ring.
|
|
|
|
The caller is responsible to stop the host from using this ring before
|
|
invoking this function: the VSTAT_DRIVER_OK bit must be clear in
|
|
VhdrDeviceStatus.
|
|
|
|
@param[out] Ring The virtio ring to clean up.
|
|
|
|
**/
|
|
VOID
|
|
EFIAPI
|
|
VirtioRingUninit (
|
|
IN OUT VRING *Ring
|
|
)
|
|
{
|
|
FreePages (Ring->Base, Ring->NumPages);
|
|
SetMem (Ring, sizeof *Ring, 0x00);
|
|
}
|
|
|
|
|
|
/**
|
|
|
|
Turn off interrupt notifications from the host, and prepare for appending
|
|
multiple descriptors to the virtio ring.
|
|
|
|
The calling driver must be in VSTAT_DRIVER_OK state.
|
|
|
|
@param[in,out] Ring The virtio ring we intend to append descriptors to.
|
|
|
|
@param[out] Indices The DESC_INDICES structure to initialize.
|
|
|
|
**/
|
|
VOID
|
|
EFIAPI
|
|
VirtioPrepare (
|
|
IN OUT VRING *Ring,
|
|
OUT DESC_INDICES *Indices
|
|
)
|
|
{
|
|
//
|
|
// 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.
|
|
//
|
|
*Ring->Avail.Flags = (UINT16) VRING_AVAIL_F_NO_INTERRUPT;
|
|
|
|
//
|
|
// Prepare for virtio-0.9.5, 2.4.1 Supplying Buffers to the Device.
|
|
//
|
|
// Since we support only one in-flight descriptor chain, we can always build
|
|
// that chain starting at entry #0 of the descriptor table.
|
|
//
|
|
Indices->HeadDescIdx = 0;
|
|
Indices->NextDescIdx = Indices->HeadDescIdx;
|
|
}
|
|
|
|
|
|
/**
|
|
|
|
Append a contiguous buffer for transmission / reception via the virtio ring.
|
|
|
|
This function implements the following section from virtio-0.9.5:
|
|
- 2.4.1.1 Placing Buffers into the Descriptor Table
|
|
|
|
Free space is taken as granted, since the individual drivers support only
|
|
synchronous requests and host side status is processed in lock-step with
|
|
request submission. It is the calling driver's responsibility to verify the
|
|
ring size in advance.
|
|
|
|
The caller is responsible for initializing *Indices with VirtioPrepare()
|
|
first.
|
|
|
|
@param[in,out] Ring The virtio ring to append the buffer to, as a
|
|
descriptor.
|
|
|
|
@param[in] BufferPhysAddr (Guest pseudo-physical) start address of the
|
|
transmit / receive buffer.
|
|
|
|
@param[in] BufferSize Number of bytes to transmit or receive.
|
|
|
|
@param[in] Flags A bitmask of VRING_DESC_F_* flags. The caller
|
|
computes this mask dependent on further buffers to
|
|
append and transfer direction.
|
|
VRING_DESC_F_INDIRECT is unsupported. The
|
|
VRING_DESC.Next field is always set, but the host
|
|
only interprets it dependent on VRING_DESC_F_NEXT.
|
|
|
|
@param[in,out] Indices Indices->HeadDescIdx is not accessed.
|
|
On input, Indices->NextDescIdx identifies the next
|
|
descriptor to carry the buffer. On output,
|
|
Indices->NextDescIdx is incremented by one, modulo
|
|
2^16.
|
|
|
|
**/
|
|
VOID
|
|
EFIAPI
|
|
VirtioAppendDesc (
|
|
IN OUT VRING *Ring,
|
|
IN UINTN BufferPhysAddr,
|
|
IN UINT32 BufferSize,
|
|
IN UINT16 Flags,
|
|
IN OUT DESC_INDICES *Indices
|
|
)
|
|
{
|
|
volatile VRING_DESC *Desc;
|
|
|
|
Desc = &Ring->Desc[Indices->NextDescIdx++ % Ring->QueueSize];
|
|
Desc->Addr = BufferPhysAddr;
|
|
Desc->Len = BufferSize;
|
|
Desc->Flags = Flags;
|
|
Desc->Next = Indices->NextDescIdx % Ring->QueueSize;
|
|
}
|
|
|
|
|
|
/**
|
|
|
|
Notify the host about the descriptor chain just built, and wait until the
|
|
host processes it.
|
|
|
|
@param[in] VirtIo The target virtio device to notify.
|
|
|
|
@param[in] VirtQueueId Identifies the queue for the target device.
|
|
|
|
@param[in,out] Ring The virtio ring with descriptors to submit.
|
|
|
|
@param[in] Indices Indices->NextDescIdx is not accessed.
|
|
Indices->HeadDescIdx identifies the head descriptor
|
|
of the descriptor chain.
|
|
|
|
|
|
@return Error code from VirtIo->SetQueueNotify() if it fails.
|
|
|
|
@retval EFI_SUCCESS Otherwise, the host processed all descriptors.
|
|
|
|
**/
|
|
EFI_STATUS
|
|
EFIAPI
|
|
VirtioFlush (
|
|
IN VIRTIO_DEVICE_PROTOCOL *VirtIo,
|
|
IN UINT16 VirtQueueId,
|
|
IN OUT VRING *Ring,
|
|
IN DESC_INDICES *Indices
|
|
)
|
|
{
|
|
UINT16 NextAvailIdx;
|
|
EFI_STATUS Status;
|
|
UINTN PollPeriodUsecs;
|
|
|
|
//
|
|
// virtio-0.9.5, 2.4.1.2 Updating the Available Ring
|
|
//
|
|
// It is not exactly clear from the wording of the virtio-0.9.5
|
|
// specification, but each entry in the Available Ring references only the
|
|
// head descriptor of any given descriptor chain.
|
|
//
|
|
NextAvailIdx = *Ring->Avail.Idx;
|
|
Ring->Avail.Ring[NextAvailIdx++ % Ring->QueueSize] =
|
|
Indices->HeadDescIdx % Ring->QueueSize;
|
|
|
|
//
|
|
// virtio-0.9.5, 2.4.1.3 Updating the Index Field
|
|
//
|
|
MemoryFence();
|
|
*Ring->Avail.Idx = NextAvailIdx;
|
|
|
|
//
|
|
// virtio-0.9.5, 2.4.1.4 Notifying the Device -- gratuitous notifications are
|
|
// OK.
|
|
//
|
|
MemoryFence();
|
|
Status = VirtIo->SetQueueNotify (VirtIo, VirtQueueId);
|
|
if (EFI_ERROR (Status)) {
|
|
return Status;
|
|
}
|
|
|
|
//
|
|
// virtio-0.9.5, 2.4.2 Receiving Used Buffers From the Device
|
|
// Wait until the host processes and acknowledges our descriptor chain. The
|
|
// condition we use for polling is greatly simplified and relies on the
|
|
// synchronous, lock-step progress.
|
|
//
|
|
// Keep slowing down until we reach a poll period of slightly above 1 ms.
|
|
//
|
|
PollPeriodUsecs = 1;
|
|
MemoryFence();
|
|
while (*Ring->Used.Idx != NextAvailIdx) {
|
|
gBS->Stall (PollPeriodUsecs); // calls AcpiTimerLib::MicroSecondDelay
|
|
|
|
if (PollPeriodUsecs < 1024) {
|
|
PollPeriodUsecs *= 2;
|
|
}
|
|
MemoryFence();
|
|
}
|
|
|
|
MemoryFence();
|
|
return EFI_SUCCESS;
|
|
}
|