aboutsummaryrefslogtreecommitdiff
path: root/drivers/staging/hv/RingBuffer.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/staging/hv/RingBuffer.c')
-rw-r--r--drivers/staging/hv/RingBuffer.c606
1 files changed, 0 insertions, 606 deletions
diff --git a/drivers/staging/hv/RingBuffer.c b/drivers/staging/hv/RingBuffer.c
deleted file mode 100644
index f69ae33a91e..00000000000
--- a/drivers/staging/hv/RingBuffer.c
+++ /dev/null
@@ -1,606 +0,0 @@
-/*
- *
- * Copyright (c) 2009, Microsoft Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
- * Place - Suite 330, Boston, MA 02111-1307 USA.
- *
- * Authors:
- * Haiyang Zhang <haiyangz@microsoft.com>
- * Hank Janssen <hjanssen@microsoft.com>
- *
- */
-
-#include <linux/kernel.h>
-#include <linux/mm.h>
-#include "osd.h"
-#include "logging.h"
-#include "RingBuffer.h"
-
-
-/* #defines */
-
-
-/* Amount of space to write to */
-#define BYTES_AVAIL_TO_WRITE(r, w, z) ((w) >= (r))?((z) - ((w) - (r))):((r) - (w))
-
-
-/*++
-
-Name:
- GetRingBufferAvailBytes()
-
-Description:
- Get number of bytes available to read and to write to
- for the specified ring buffer
-
---*/
-static inline void
-GetRingBufferAvailBytes(RING_BUFFER_INFO *rbi, u32 *read, u32 *write)
-{
- u32 read_loc,write_loc;
-
- /* Capture the read/write indices before they changed */
- read_loc = rbi->RingBuffer->ReadIndex;
- write_loc = rbi->RingBuffer->WriteIndex;
-
- *write = BYTES_AVAIL_TO_WRITE(read_loc, write_loc, rbi->RingDataSize);
- *read = rbi->RingDataSize - *write;
-}
-
-/*++
-
-Name:
- GetNextWriteLocation()
-
-Description:
- Get the next write location for the specified ring buffer
-
---*/
-static inline u32
-GetNextWriteLocation(RING_BUFFER_INFO* RingInfo)
-{
- u32 next = RingInfo->RingBuffer->WriteIndex;
-
- ASSERT(next < RingInfo->RingDataSize);
-
- return next;
-}
-
-/*++
-
-Name:
- SetNextWriteLocation()
-
-Description:
- Set the next write location for the specified ring buffer
-
---*/
-static inline void
-SetNextWriteLocation(RING_BUFFER_INFO* RingInfo, u32 NextWriteLocation)
-{
- RingInfo->RingBuffer->WriteIndex = NextWriteLocation;
-}
-
-/*++
-
-Name:
- GetNextReadLocation()
-
-Description:
- Get the next read location for the specified ring buffer
-
---*/
-static inline u32
-GetNextReadLocation(RING_BUFFER_INFO* RingInfo)
-{
- u32 next = RingInfo->RingBuffer->ReadIndex;
-
- ASSERT(next < RingInfo->RingDataSize);
-
- return next;
-}
-
-/*++
-
-Name:
- GetNextReadLocationWithOffset()
-
-Description:
- Get the next read location + offset for the specified ring buffer.
- This allows the caller to skip
-
---*/
-static inline u32
-GetNextReadLocationWithOffset(RING_BUFFER_INFO* RingInfo, u32 Offset)
-{
- u32 next = RingInfo->RingBuffer->ReadIndex;
-
- ASSERT(next < RingInfo->RingDataSize);
- next += Offset;
- next %= RingInfo->RingDataSize;
-
- return next;
-}
-
-/*++
-
-Name:
- SetNextReadLocation()
-
-Description:
- Set the next read location for the specified ring buffer
-
---*/
-static inline void
-SetNextReadLocation(RING_BUFFER_INFO* RingInfo, u32 NextReadLocation)
-{
- RingInfo->RingBuffer->ReadIndex = NextReadLocation;
-}
-
-
-/*++
-
-Name:
- GetRingBuffer()
-
-Description:
- Get the start of the ring buffer
-
---*/
-static inline void *
-GetRingBuffer(RING_BUFFER_INFO* RingInfo)
-{
- return (void *)RingInfo->RingBuffer->Buffer;
-}
-
-
-/*++
-
-Name:
- GetRingBufferSize()
-
-Description:
- Get the size of the ring buffer
-
---*/
-static inline u32
-GetRingBufferSize(RING_BUFFER_INFO* RingInfo)
-{
- return RingInfo->RingDataSize;
-}
-
-/*++
-
-Name:
- GetRingBufferIndices()
-
-Description:
- Get the read and write indices as u64 of the specified ring buffer
-
---*/
-static inline u64
-GetRingBufferIndices(RING_BUFFER_INFO* RingInfo)
-{
- return ((u64)RingInfo->RingBuffer->WriteIndex << 32) || RingInfo->RingBuffer->ReadIndex;
-}
-
-
-/*++
-
-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);
-}
-
-
-/* Internal routines */
-
-static u32
-CopyToRingBuffer(
- RING_BUFFER_INFO *RingInfo,
- u32 StartWriteOffset,
- void * Src,
- u32 SrcLen);
-
-static u32
-CopyFromRingBuffer(
- RING_BUFFER_INFO *RingInfo,
- void * Dest,
- u32 DestLen,
- u32 StartReadOffset);
-
-
-
-/*++
-
-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:
- GetRingBufferInterruptMask()
-
-Description:
- Get the interrupt mask for the specified ring buffer
-
---*/
-u32 GetRingBufferInterruptMask(RING_BUFFER_INFO *rbi)
-{
- return rbi->RingBuffer->InterruptMask;
-}
-
-/*++
-
-Name:
- RingBufferInit()
-
-Description:
- Initialize the ring buffer
-
---*/
-int RingBufferInit(RING_BUFFER_INFO *RingInfo, void *Buffer, u32 BufferLen)
-{
- ASSERT(sizeof(RING_BUFFER) == PAGE_SIZE);
-
- memset(RingInfo, 0, sizeof(RING_BUFFER_INFO));
-
- RingInfo->RingBuffer = (RING_BUFFER*)Buffer;
- RingInfo->RingBuffer->ReadIndex = RingInfo->RingBuffer->WriteIndex = 0;
-
- RingInfo->RingSize = BufferLen;
- RingInfo->RingDataSize = BufferLen - sizeof(RING_BUFFER);
-
- spin_lock_init(&RingInfo->ring_lock);
-
- return 0;
-}
-
-/*++
-
-Name:
- RingBufferCleanup()
-
-Description:
- Cleanup the ring buffer
-
---*/
-void RingBufferCleanup(RING_BUFFER_INFO* RingInfo)
-{
-}
-
-/*++
-
-Name:
- RingBufferWrite()
-
-Description:
- Write to the ring buffer
-
---*/
-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);
- }
-
- /* Set previous packet start */
- prevIndices = GetRingBufferIndices(OutRingInfo);
-
- nextWriteLocation = CopyToRingBuffer(OutRingInfo,
- nextWriteLocation,
- &prevIndices,
- sizeof(u64));
-
- /* Make sure we flush all writes before updating the writeIndex */
- mb();
-
- /* Now, update the write location */
- SetNextWriteLocation(OutRingInfo, nextWriteLocation);
-
- /* DumpRingInfo(OutRingInfo, "AFTER "); */
-
- spin_unlock_irqrestore(&OutRingInfo->ring_lock, flags);
-
- DPRINT_EXIT(VMBUS);
-
- return 0;
-}
-
-
-/*++
-
-Name:
- RingBufferPeek()
-
-Description:
- Read without advancing the read index
-
---*/
-int RingBufferPeek(RING_BUFFER_INFO *InRingInfo, void *Buffer, u32 BufferLen)
-{
- u32 bytesAvailToWrite;
- u32 bytesAvailToRead;
- u32 nextReadLocation=0;
- unsigned long flags;
-
- spin_lock_irqsave(&InRingInfo->ring_lock, flags);
-
- 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); */
-
- spin_unlock_irqrestore(&InRingInfo->ring_lock, flags);
-
- return -1;
- }
-
- /* Convert to byte offset */
- nextReadLocation = GetNextReadLocation(InRingInfo);
-
- nextReadLocation = CopyFromRingBuffer(InRingInfo,
- Buffer,
- BufferLen,
- nextReadLocation);
-
- spin_unlock_irqrestore(&InRingInfo->ring_lock, flags);
-
- return 0;
-}
-
-
-/*++
-
-Name:
- RingBufferRead()
-
-Description:
- Read and advance the read index
-
---*/
-int RingBufferRead(RING_BUFFER_INFO *InRingInfo, void *Buffer,
- u32 BufferLen, u32 Offset)
-{
- u32 bytesAvailToWrite;
- u32 bytesAvailToRead;
- u32 nextReadLocation=0;
- u64 prevIndices=0;
- unsigned long flags;
-
- ASSERT(BufferLen > 0);
-
- spin_lock_irqsave(&InRingInfo->ring_lock, flags);
-
- 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);
-
- spin_unlock_irqrestore(&InRingInfo->ring_lock, flags);
-
- return -1;
- }
-
- nextReadLocation = GetNextReadLocationWithOffset(InRingInfo, Offset);
-
- nextReadLocation = CopyFromRingBuffer(InRingInfo,
- Buffer,
- BufferLen,
- nextReadLocation);
-
- nextReadLocation = CopyFromRingBuffer(InRingInfo,
- &prevIndices,
- sizeof(u64),
- 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 */
- mb();
-
- /* Update the read index */
- SetNextReadLocation(InRingInfo, nextReadLocation);
-
- /* DumpRingInfo(InRingInfo, "AFTER "); */
-
- spin_unlock_irqrestore(&InRingInfo->ring_lock, flags);
-
- return 0;
-}
-
-
-/*++
-
-Name:
- CopyToRingBuffer()
-
-Description:
- Helper routine to copy from source to ring buffer.
- Assume there is enough room. Handles wrap-around in dest case only!!
-
---*/
-static u32
-CopyToRingBuffer(
- RING_BUFFER_INFO *RingInfo,
- u32 StartWriteOffset,
- void * Src,
- u32 SrcLen)
-{
- void * ringBuffer=GetRingBuffer(RingInfo);
- u32 ringBufferSize=GetRingBufferSize(RingInfo);
- u32 fragLen;
-
- if (SrcLen > ringBufferSize - StartWriteOffset) /* wrap-around detected! */
- {
- DPRINT_DBG(VMBUS, "wrap-around detected!");
-
- fragLen = ringBufferSize - StartWriteOffset;
- memcpy(ringBuffer + StartWriteOffset, Src, fragLen);
- memcpy(ringBuffer, Src + fragLen, SrcLen - fragLen);
- }
- else
- {
- memcpy(ringBuffer + StartWriteOffset, Src, SrcLen);
- }
-
- StartWriteOffset += SrcLen;
- StartWriteOffset %= ringBufferSize;
-
- return StartWriteOffset;
-}
-
-
-/*++
-
-Name:
- CopyFromRingBuffer()
-
-Description:
- Helper routine to copy to source from ring buffer.
- Assume there is enough room. Handles wrap-around in src case only!!
-
---*/
-static u32
-CopyFromRingBuffer(
- RING_BUFFER_INFO *RingInfo,
- void * Dest,
- u32 DestLen,
- u32 StartReadOffset)
-{
- void * ringBuffer=GetRingBuffer(RingInfo);
- u32 ringBufferSize=GetRingBufferSize(RingInfo);
-
- u32 fragLen;
-
- if (DestLen > ringBufferSize - StartReadOffset) /* wrap-around detected at the src */
- {
- DPRINT_DBG(VMBUS, "src wrap-around detected!");
-
- fragLen = ringBufferSize - StartReadOffset;
-
- memcpy(Dest, ringBuffer + StartReadOffset, fragLen);
- memcpy(Dest + fragLen, ringBuffer, DestLen - fragLen);
- }
- else
- {
- memcpy(Dest, ringBuffer + StartReadOffset, DestLen);
- }
-
- StartReadOffset += DestLen;
- StartReadOffset %= ringBufferSize;
-
- return StartReadOffset;
-}
-
-
-/* eof */