#include <linux/list.h>
#include <linux/timer.h>
-#include "RingBuffer.h"
+#include "ring_buffer.h"
#include "VmbusChannelInterface.h"
#include "VmbusPacketFormat.h"
hv_vmbus-objs := vmbus_drv.o osd.o \
Vmbus.o hv.o connection.o channel.o \
- ChannelMgmt.o ChannelInterface.o RingBuffer.o
+ ChannelMgmt.o ChannelInterface.o ring_buffer.o
hv_storvsc-objs := storvsc_drv.o StorVsc.o
hv_blkvsc-objs := blkvsc_drv.o BlkVsc.o
hv_netvsc-objs := netvsc_drv.o NetVsc.o RndisFilter.o
+++ /dev/null
-/*
- *
- * 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)
-{
- if (sizeof(RING_BUFFER) != PAGE_SIZE)
- return -EINVAL;
-
- 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;
-
- if (BufferLen <= 0)
- return -EINVAL;
-
- 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;
-
- /* wrap-around detected! */
- if (SrcLen > ringBufferSize - StartWriteOffset) {
- 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;
-
- /* wrap-around detected at the src */
- if (DestLen > ringBufferSize - StartReadOffset) {
- 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 */
+++ /dev/null
-/*
- *
- * 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>
- *
- */
-
-
-#ifndef _RING_BUFFER_H_
-#define _RING_BUFFER_H_
-
-#include <linux/scatterlist.h>
-
-typedef struct _RING_BUFFER {
- /* Offset in bytes from the start of ring data below */
- volatile u32 WriteIndex;
-
- /* Offset in bytes from the start of ring data below */
- volatile u32 ReadIndex;
-
- volatile u32 InterruptMask;
-
- /* Pad it to PAGE_SIZE so that data starts on page boundary */
- u8 Reserved[4084];
-
- /* NOTE:
- * The InterruptMask field is used only for channels but since our
- * vmbus connection also uses this data structure and its data starts
- * here, we commented out this field.
- */
- /* volatile u32 InterruptMask; */
-
- /*
- * Ring data starts here + RingDataStartOffset
- * !!! DO NOT place any fields below this !!!
- */
- u8 Buffer[0];
-} __attribute__((packed)) RING_BUFFER;
-
-typedef struct _RING_BUFFER_INFO {
- RING_BUFFER *RingBuffer;
- u32 RingSize; /* Include the shared header */
- spinlock_t ring_lock;
-
- u32 RingDataSize; /* < ringSize */
- u32 RingDataStartOffset;
-
-} RING_BUFFER_INFO;
-
-typedef struct _RING_BUFFER_DEBUG_INFO {
- u32 CurrentInterruptMask;
- u32 CurrentReadIndex;
- u32 CurrentWriteIndex;
- u32 BytesAvailToRead;
- u32 BytesAvailToWrite;
-} RING_BUFFER_DEBUG_INFO;
-
-
-
-/* Interface */
-
-
-int RingBufferInit(RING_BUFFER_INFO *RingInfo, void *Buffer, u32 BufferLen);
-
-void RingBufferCleanup(RING_BUFFER_INFO *RingInfo);
-
-int RingBufferWrite(RING_BUFFER_INFO *RingInfo,
- struct scatterlist *sglist,
- u32 sgcount);
-
-int RingBufferPeek(RING_BUFFER_INFO *RingInfo, void *Buffer, u32 BufferLen);
-
-int RingBufferRead(RING_BUFFER_INFO *RingInfo,
- void *Buffer,
- u32 BufferLen,
- u32 Offset);
-
-u32 GetRingBufferInterruptMask(RING_BUFFER_INFO *RingInfo);
-
-void DumpRingInfo(RING_BUFFER_INFO *RingInfo, char *Prefix);
-
-void RingBufferGetDebugInfo(RING_BUFFER_INFO *RingInfo,
- RING_BUFFER_DEBUG_INFO *DebugInfo);
-
-#endif /* _RING_BUFFER_H_ */
#include "channel.h"
#include "ChannelMgmt.h"
#include "ChannelInterface.h"
-#include "RingBuffer.h"
+#include "ring_buffer.h"
#include <linux/list.h>
--- /dev/null
+/*
+ *
+ * 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 "ring_buffer.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)
+{
+ if (sizeof(RING_BUFFER) != PAGE_SIZE)
+ return -EINVAL;
+
+ 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;
+
+ if (BufferLen <= 0)
+ return -EINVAL;
+
+ 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;
+
+ /* wrap-around detected! */
+ if (SrcLen > ringBufferSize - StartWriteOffset) {
+ 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;
+
+ /* wrap-around detected at the src */
+ if (DestLen > ringBufferSize - StartReadOffset) {
+ 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 */
--- /dev/null
+/*
+ *
+ * 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>
+ *
+ */
+
+
+#ifndef _RING_BUFFER_H_
+#define _RING_BUFFER_H_
+
+#include <linux/scatterlist.h>
+
+typedef struct _RING_BUFFER {
+ /* Offset in bytes from the start of ring data below */
+ volatile u32 WriteIndex;
+
+ /* Offset in bytes from the start of ring data below */
+ volatile u32 ReadIndex;
+
+ volatile u32 InterruptMask;
+
+ /* Pad it to PAGE_SIZE so that data starts on page boundary */
+ u8 Reserved[4084];
+
+ /* NOTE:
+ * The InterruptMask field is used only for channels but since our
+ * vmbus connection also uses this data structure and its data starts
+ * here, we commented out this field.
+ */
+ /* volatile u32 InterruptMask; */
+
+ /*
+ * Ring data starts here + RingDataStartOffset
+ * !!! DO NOT place any fields below this !!!
+ */
+ u8 Buffer[0];
+} __attribute__((packed)) RING_BUFFER;
+
+typedef struct _RING_BUFFER_INFO {
+ RING_BUFFER *RingBuffer;
+ u32 RingSize; /* Include the shared header */
+ spinlock_t ring_lock;
+
+ u32 RingDataSize; /* < ringSize */
+ u32 RingDataStartOffset;
+
+} RING_BUFFER_INFO;
+
+typedef struct _RING_BUFFER_DEBUG_INFO {
+ u32 CurrentInterruptMask;
+ u32 CurrentReadIndex;
+ u32 CurrentWriteIndex;
+ u32 BytesAvailToRead;
+ u32 BytesAvailToWrite;
+} RING_BUFFER_DEBUG_INFO;
+
+
+
+/* Interface */
+
+
+int RingBufferInit(RING_BUFFER_INFO *RingInfo, void *Buffer, u32 BufferLen);
+
+void RingBufferCleanup(RING_BUFFER_INFO *RingInfo);
+
+int RingBufferWrite(RING_BUFFER_INFO *RingInfo,
+ struct scatterlist *sglist,
+ u32 sgcount);
+
+int RingBufferPeek(RING_BUFFER_INFO *RingInfo, void *Buffer, u32 BufferLen);
+
+int RingBufferRead(RING_BUFFER_INFO *RingInfo,
+ void *Buffer,
+ u32 BufferLen,
+ u32 Offset);
+
+u32 GetRingBufferInterruptMask(RING_BUFFER_INFO *RingInfo);
+
+void DumpRingInfo(RING_BUFFER_INFO *RingInfo, char *Prefix);
+
+void RingBufferGetDebugInfo(RING_BUFFER_INFO *RingInfo,
+ RING_BUFFER_DEBUG_INFO *DebugInfo);
+
+#endif /* _RING_BUFFER_H_ */
projects / linux-2.6-block.git / commitdiff