int RingBufferWrite(RING_BUFFER_INFO *OutRingInfo,
struct scatterlist *sglist, u32 sgcount)
{
int i = 0;
u32 byteAvailToWrite;
u32 byteAvailToRead;
u32 totalBytesToWrite = 0;
struct scatterlist *sg;
volatile u32 nextWriteLocation;
u64 prevIndices = 0;
unsigned long flags;
DPRINT_ENTER(VMBUS);
for_each_sg(sglist, sg, sgcount, i)
{
totalBytesToWrite += sg->length;
}
totalBytesToWrite += sizeof(u64);
spin_lock_irqsave(&OutRingInfo->ring_lock, flags);
GetRingBufferAvailBytes(OutRingInfo,
&byteAvailToRead,
&byteAvailToWrite);
DPRINT_DBG(VMBUS, "Writing %u bytes...", totalBytesToWrite);
/* DumpRingInfo(OutRingInfo, "BEFORE "); */
/* If there is only room for the packet, assume it is full. */
/* Otherwise, the next time around, we think the ring buffer */
/* is empty since the read index == write index */
if (byteAvailToWrite <= totalBytesToWrite) {
DPRINT_DBG(VMBUS,
"No more space left on outbound ring buffer "
"(needed %u, avail %u)",
totalBytesToWrite,
byteAvailToWrite);
spin_unlock_irqrestore(&OutRingInfo->ring_lock, flags);
DPRINT_EXIT(VMBUS);
return -1;
}
/* Write to the ring buffer */
nextWriteLocation = GetNextWriteLocation(OutRingInfo);
for_each_sg(sglist, sg, sgcount, i)
{
nextWriteLocation = CopyToRingBuffer(OutRingInfo,
nextWriteLocation,
sg_virt(sg),
sg->length);
}
/*++
Name:
RingBufferRead()
Description:
Read and advance the read index
--*/
int
RingBufferRead(
RING_BUFFER_INFO* InRingInfo,
PVOID Buffer,
UINT32 BufferLen,
UINT32 Offset
)
{
UINT32 bytesAvailToWrite;
UINT32 bytesAvailToRead;
UINT32 nextReadLocation=0;
UINT64 prevIndices=0;
ASSERT(BufferLen > 0);
SpinlockAcquire(InRingInfo->RingLock);
GetRingBufferAvailBytes(InRingInfo, &bytesAvailToRead, &bytesAvailToWrite);
DPRINT_DBG(VMBUS, "Reading %u bytes...", BufferLen);
//DumpRingInfo(InRingInfo, "BEFORE ");
// Make sure there is something to read
if (bytesAvailToRead < BufferLen )
{
DPRINT_DBG(VMBUS, "got callback but not enough to read <avail to read %d read size %d>!!", bytesAvailToRead, BufferLen);
SpinlockRelease(InRingInfo->RingLock);
return -1;
}
nextReadLocation = GetNextReadLocationWithOffset(InRingInfo, Offset);
nextReadLocation = CopyFromRingBuffer(InRingInfo,
Buffer,
BufferLen,
nextReadLocation);
nextReadLocation = CopyFromRingBuffer(InRingInfo,
&prevIndices,
sizeof(UINT64),
nextReadLocation);
// Make sure all reads are done before we update the read index since
// the writer may start writing to the read area once the read index is updated
MemoryFence();
// Update the read index
SetNextReadLocation(InRingInfo, nextReadLocation);
//DumpRingInfo(InRingInfo, "AFTER ");
SpinlockRelease(InRingInfo->RingLock);
return 0;
}
int RingBufferWrite(RING_BUFFER_INFO *OutRingInfo,
struct scatterlist *sglist, u32 sgcount)
{
int i=0;
u32 byteAvailToWrite;
u32 byteAvailToRead;
u32 totalBytesToWrite=0;
struct scatterlist *sg;
volatile u32 nextWriteLocation;
u64 prevIndices=0;
unsigned long flags;
DPRINT_ENTER(VMBUS);
for_each_sg(sglist, sg, sgcount, i)
{
totalBytesToWrite += sg->length;
}
totalBytesToWrite += sizeof(u64);
spin_lock_irqsave(&OutRingInfo->ring_lock, flags);
GetRingBufferAvailBytes(OutRingInfo, &byteAvailToRead, &byteAvailToWrite);
DPRINT_DBG(VMBUS, "Writing %u bytes...", totalBytesToWrite);
if (byteAvailToWrite <= totalBytesToWrite)
{
DPRINT_DBG(VMBUS, "No more space left on outbound ring buffer (needed %u, avail %u)", totalBytesToWrite, byteAvailToWrite);
spin_unlock_irqrestore(&OutRingInfo->ring_lock, flags);
DPRINT_EXIT(VMBUS);
return -1;
}
nextWriteLocation = GetNextWriteLocation(OutRingInfo);
for_each_sg(sglist, sg, sgcount, i)
{
nextWriteLocation = CopyToRingBuffer(OutRingInfo,
nextWriteLocation,
sg_virt(sg),
sg->length);
}
/*++
Name:
DumpRingInfo()
Description:
Dump out to console the ring buffer info
--*/
void DumpRingInfo(RING_BUFFER_INFO *RingInfo, char *Prefix)
{
u32 bytesAvailToWrite;
u32 bytesAvailToRead;
GetRingBufferAvailBytes(RingInfo, &bytesAvailToRead, &bytesAvailToWrite);
DPRINT(VMBUS, DEBUG_RING_LVL, "%s <<ringinfo %p buffer %p avail write %u avail read %u read idx %u write idx %u>>",
Prefix,
RingInfo,
RingInfo->RingBuffer->Buffer,
bytesAvailToWrite,
bytesAvailToRead,
RingInfo->RingBuffer->ReadIndex,
RingInfo->RingBuffer->WriteIndex);
}
/*++
Name:
RingBufferGetDebugInfo()
Description:
Get various debug metrics for the specified ring buffer
--*/
void RingBufferGetDebugInfo(RING_BUFFER_INFO *RingInfo,
RING_BUFFER_DEBUG_INFO *DebugInfo)
{
u32 bytesAvailToWrite;
u32 bytesAvailToRead;
if (RingInfo->RingBuffer)
{
GetRingBufferAvailBytes(RingInfo, &bytesAvailToRead, &bytesAvailToWrite);
DebugInfo->BytesAvailToRead = bytesAvailToRead;
DebugInfo->BytesAvailToWrite = bytesAvailToWrite;
DebugInfo->CurrentReadIndex = RingInfo->RingBuffer->ReadIndex;
DebugInfo->CurrentWriteIndex = RingInfo->RingBuffer->WriteIndex;
DebugInfo->CurrentInterruptMask = RingInfo->RingBuffer->InterruptMask;
}
}
/*++
Name:
RingBufferGetDebugInfo()
Description:
Get various debug metrics for the specified ring buffer
--*/
void RingBufferGetDebugInfo(struct hv_ring_buffer_info *RingInfo,
struct hv_ring_buffer_debug_info *debug_info)
{
u32 bytesAvailToWrite;
u32 bytesAvailToRead;
if (RingInfo->RingBuffer) {
GetRingBufferAvailBytes(RingInfo,
&bytesAvailToRead,
&bytesAvailToWrite);
debug_info->BytesAvailToRead = bytesAvailToRead;
debug_info->BytesAvailToWrite = bytesAvailToWrite;
debug_info->CurrentReadIndex = RingInfo->RingBuffer->ReadIndex;
debug_info->CurrentWriteIndex = RingInfo->RingBuffer->WriteIndex;
debug_info->CurrentInterruptMask = RingInfo->RingBuffer->InterruptMask;
}
}
/*++
Name:
RingBufferPeek()
Description:
Read without advancing the read index
--*/
int
RingBufferPeek(
RING_BUFFER_INFO* InRingInfo,
void* Buffer,
UINT32 BufferLen
)
{
UINT32 bytesAvailToWrite;
UINT32 bytesAvailToRead;
UINT32 nextReadLocation=0;
SpinlockAcquire(InRingInfo->RingLock);
GetRingBufferAvailBytes(InRingInfo, &bytesAvailToRead, &bytesAvailToWrite);
// Make sure there is something to read
if (bytesAvailToRead < BufferLen )
{
//DPRINT_DBG(VMBUS, "got callback but not enough to read <avail to read %d read size %d>!!", bytesAvailToRead, BufferLen);
SpinlockRelease(InRingInfo->RingLock);
return -1;
}
// Convert to byte offset
nextReadLocation = GetNextReadLocation(InRingInfo);
nextReadLocation = CopyFromRingBuffer(InRingInfo,
Buffer,
BufferLen,
nextReadLocation);
SpinlockRelease(InRingInfo->RingLock);
return 0;
}
int
RingBufferCheck(RING_BUFFER_INFO *rbi)
{
#if 1
UINT32 ri, wi, len;
// Capture the read/write indices before they changed
ri = rbi->RingBuffer->ReadIndex;
wi = rbi->RingBuffer->WriteIndex;
len = (ri <= wi) ? (wi - ri) : (rbi->RingDataSize - (ri - wi));
if (len < sizeof(VMPACKET_DESCRIPTOR))
return 0;
_PREFETCHT0(rbi->RingBuffer->Buffer + ri);
#if 0
if (ri <= wi) {
/* no wrap */
while (len > 0) {
_PREFETCHT0(rbi->RingBuffer->Buffer + ri);
len -= 128;
ri += 128;
}
} else {
/* wrap */
while (ri < rbi->RingDataSize) {
_PREFETCHT0(rbi->RingBuffer->Buffer + ri);
len -= 128;
ri += 128;
}
ri = 0;
while (len > 0) {
_PREFETCHT0(rbi->RingBuffer->Buffer + ri);
len -= 128;
ri += 128;
}
}
#endif
return 1;
#else
UINT32 toRead = 0;
UINT32 toWrite;
UINT32 addr;
int i;
GetRingBufferAvailBytes(rbi, &toRead, &toWrite);
if (toRead < sizeof(VMPACKET_DESCRIPTOR))
return 0;
else {
r = rbi->Ringbuffer;
rdindx = r->ReadIndex;
addr = r->Buffer + rdindx;
toRead += (addr & 0x~07f);
addr &= ~0x7f;
if (toRead > r->size - rdindx) {
end = buf + size;
for(;addr < end; ) {
_PREFETCHT0(addr & ~0x7f);
addr += 128;
}
} else {
_PREFETCH0(addr & ~0x7f);
}
return 1;
}
#endif
}
/*++
Name:
RingBufferWrite()
Description:
Write to the ring buffer
--*/
int
RingBufferWrite(
RING_BUFFER_INFO* OutRingInfo,
SG_BUFFER_LIST SgBuffers[],
UINT32 SgBufferCount
)
{
int i=0;
UINT32 byteAvailToWrite;
UINT32 byteAvailToRead;
UINT32 totalBytesToWrite=0;
volatile UINT32 nextWriteLocation;
UINT64 prevIndices=0;
DPRINT_ENTER(VMBUS);
for (i=0; i < SgBufferCount; i++)
{
totalBytesToWrite += SgBuffers[i].Length;
}
totalBytesToWrite += sizeof(UINT64);
SpinlockAcquire(OutRingInfo->RingLock);
GetRingBufferAvailBytes(OutRingInfo, &byteAvailToRead, &byteAvailToWrite);
DPRINT_DBG(VMBUS, "Writing %u bytes...", totalBytesToWrite);
//DumpRingInfo(OutRingInfo, "BEFORE ");
// If there is only room for the packet, assume it is full. Otherwise, the next time around, we think the ring buffer
// is empty since the read index == write index
if (byteAvailToWrite <= totalBytesToWrite)
{
DPRINT_DBG(VMBUS, "No more space left on outbound ring buffer (needed %u, avail %u)", totalBytesToWrite, byteAvailToWrite);
SpinlockRelease(OutRingInfo->RingLock);
DPRINT_EXIT(VMBUS);
return -1;
}
// Write to the ring buffer
nextWriteLocation = GetNextWriteLocation(OutRingInfo);
for (i=0; i < SgBufferCount; i++)
{
nextWriteLocation = CopyToRingBuffer(OutRingInfo,
nextWriteLocation,
SgBuffers[i].Data,
SgBuffers[i].Length);
}
// Set previous packet start
prevIndices = GetRingBufferIndices(OutRingInfo);
nextWriteLocation = CopyToRingBuffer(OutRingInfo,
nextWriteLocation,
&prevIndices,
sizeof(UINT64));
// Make sure we flush all writes before updating the writeIndex
MemoryFence();
// Now, update the write location
SetNextWriteLocation(OutRingInfo, nextWriteLocation);
//DumpRingInfo(OutRingInfo, "AFTER ");
SpinlockRelease(OutRingInfo->RingLock);
DPRINT_EXIT(VMBUS);
return 0;
}