u32 read_loc = rbi->ring_buffer->read_index;
u32 pending_sz = rbi->ring_buffer->pending_send_sz;
- /*
- * If the other end is not blocked on write don't bother.
- */
+ /* If the other end is not blocked on write don't bother. */
if (pending_sz == 0)
return false;
return false;
}
-/*
- * hv_get_next_write_location()
- *
- * Get the next write location for the specified ring buffer
- *
- */
+/* Get the next write location for the specified ring buffer. */
static inline u32
hv_get_next_write_location(struct hv_ring_buffer_info *ring_info)
{
return next;
}
-/*
- * hv_set_next_write_location()
- *
- * Set the next write location for the specified ring buffer
- *
- */
+/* Set the next write location for the specified ring buffer. */
static inline void
hv_set_next_write_location(struct hv_ring_buffer_info *ring_info,
u32 next_write_location)
ring_info->ring_buffer->write_index = next_write_location;
}
-/*
- * hv_get_next_read_location()
- *
- * Get the next read location for the specified ring buffer
- */
+/* Get the next read location for the specified ring buffer. */
static inline u32
hv_get_next_read_location(struct hv_ring_buffer_info *ring_info)
{
}
/*
- * hv_get_next_readlocation_withoffset()
- *
* Get the next read location + offset for the specified ring buffer.
- * This allows the caller to skip
+ * This allows the caller to skip.
*/
static inline u32
hv_get_next_readlocation_withoffset(struct hv_ring_buffer_info *ring_info,
return next;
}
-/*
- *
- * hv_set_next_read_location()
- *
- * Set the next read location for the specified ring buffer
- *
- */
+/* Set the next read location for the specified ring buffer. */
static inline void
hv_set_next_read_location(struct hv_ring_buffer_info *ring_info,
u32 next_read_location)
}
-/*
- *
- * hv_get_ring_buffer()
- *
- * Get the start of the ring buffer
- */
+/* Get the start of the ring buffer. */
static inline void *
hv_get_ring_buffer(struct hv_ring_buffer_info *ring_info)
{
}
-/*
- *
- * hv_get_ring_buffersize()
- *
- * Get the size of the ring buffer
- */
+/* Get the size of the ring buffer. */
static inline u32
hv_get_ring_buffersize(struct hv_ring_buffer_info *ring_info)
{
return ring_info->ring_datasize;
}
-/*
- *
- * hv_get_ring_bufferindices()
- *
- * Get the read and write indices as u64 of the specified ring buffer
- *
- */
+/* Get the read and write indices as u64 of the specified ring buffer. */
static inline u64
hv_get_ring_bufferindices(struct hv_ring_buffer_info *ring_info)
{
}
/*
- *
- * hv_copyfrom_ringbuffer()
- *
* Helper routine to copy to source from ring buffer.
* Assume there is enough room. Handles wrap-around in src case only!!
- *
*/
static u32 hv_copyfrom_ringbuffer(
struct hv_ring_buffer_info *ring_info,
/*
- *
- * hv_copyto_ringbuffer()
- *
* Helper routine to copy from source to ring buffer.
* Assume there is enough room. Handles wrap-around in dest case only!!
- *
*/
static u32 hv_copyto_ringbuffer(
struct hv_ring_buffer_info *ring_info,
return start_write_offset;
}
-/*
- *
- * hv_ringbuffer_get_debuginfo()
- *
- * Get various debug metrics for the specified ring buffer
- *
- */
+/* Get various debug metrics for the specified ring buffer. */
void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info,
struct hv_ring_buffer_debug_info *debug_info)
{
}
}
-/*
- *
- * hv_ringbuffer_init()
- *
- *Initialize the ring buffer
- *
- */
+/* Initialize the ring buffer. */
int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
void *buffer, u32 buflen)
{
ring_info->ring_buffer->read_index =
ring_info->ring_buffer->write_index = 0;
- /*
- * Set the feature bit for enabling flow control.
- */
+ /* Set the feature bit for enabling flow control. */
ring_info->ring_buffer->feature_bits.value = 1;
ring_info->ring_size = buflen;
return 0;
}
-/*
- *
- * hv_ringbuffer_cleanup()
- *
- * Cleanup the ring buffer
- *
- */
+/* Cleanup the ring buffer. */
void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info)
{
}
-/*
- *
- * hv_ringbuffer_write()
- *
- * Write to the ring buffer
- *
- */
+/* Write to the ring buffer. */
int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
struct kvec *kv_list, u32 kv_count, bool *signal)
{
&bytes_avail_toread,
&bytes_avail_towrite);
-
- /* 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 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 (bytes_avail_towrite <= totalbytes_towrite) {
spin_unlock_irqrestore(&outring_info->ring_lock, flags);
return -EAGAIN;
return 0;
}
-
-/*
- *
- * hv_ringbuffer_peek()
- *
- * Read without advancing the read index
- *
- */
-int hv_ringbuffer_peek(struct hv_ring_buffer_info *Inring_info,
- void *Buffer, u32 buflen)
-{
- u32 bytes_avail_towrite;
- u32 bytes_avail_toread;
- u32 next_read_location = 0;
- unsigned long flags;
-
- spin_lock_irqsave(&Inring_info->ring_lock, flags);
-
- hv_get_ringbuffer_availbytes(Inring_info,
- &bytes_avail_toread,
- &bytes_avail_towrite);
-
- /* Make sure there is something to read */
- if (bytes_avail_toread < buflen) {
-
- spin_unlock_irqrestore(&Inring_info->ring_lock, flags);
-
- return -EAGAIN;
- }
-
- /* Convert to byte offset */
- next_read_location = hv_get_next_read_location(Inring_info);
-
- next_read_location = hv_copyfrom_ringbuffer(Inring_info,
- Buffer,
- buflen,
- next_read_location);
-
- spin_unlock_irqrestore(&Inring_info->ring_lock, flags);
-
- return 0;
-}
-
-
-/*
- *
- * hv_ringbuffer_read()
- *
- * Read and advance the read index
- *
- */
-int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer,
- u32 buflen, u32 offset, bool *signal)
+int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
+ void *buffer, u32 buflen, u32 *buffer_actual_len,
+ u64 *requestid, bool *signal, bool raw)
{
u32 bytes_avail_towrite;
u32 bytes_avail_toread;
u32 next_read_location = 0;
u64 prev_indices = 0;
unsigned long flags;
+ struct vmpacket_descriptor desc;
+ u32 offset;
+ u32 packetlen;
+ int ret = 0;
if (buflen <= 0)
return -EINVAL;
spin_lock_irqsave(&inring_info->ring_lock, flags);
+ *buffer_actual_len = 0;
+ *requestid = 0;
+
hv_get_ringbuffer_availbytes(inring_info,
&bytes_avail_toread,
&bytes_avail_towrite);
/* Make sure there is something to read */
- if (bytes_avail_toread < buflen) {
- spin_unlock_irqrestore(&inring_info->ring_lock, flags);
+ if (bytes_avail_toread < sizeof(desc)) {
+ /*
+ * No error is set when there is even no header, drivers are
+ * supposed to analyze buffer_actual_len.
+ */
+ goto out_unlock;
+ }
- return -EAGAIN;
+ next_read_location = hv_get_next_read_location(inring_info);
+ next_read_location = hv_copyfrom_ringbuffer(inring_info, &desc,
+ sizeof(desc),
+ next_read_location);
+
+ offset = raw ? 0 : (desc.offset8 << 3);
+ packetlen = (desc.len8 << 3) - offset;
+ *buffer_actual_len = packetlen;
+ *requestid = desc.trans_id;
+
+ if (bytes_avail_toread < packetlen + offset) {
+ ret = -EAGAIN;
+ goto out_unlock;
+ }
+
+ if (packetlen > buflen) {
+ ret = -ENOBUFS;
+ goto out_unlock;
}
next_read_location =
next_read_location = hv_copyfrom_ringbuffer(inring_info,
buffer,
- buflen,
+ packetlen,
next_read_location);
next_read_location = hv_copyfrom_ringbuffer(inring_info,
sizeof(u64),
next_read_location);
- /* 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 */
+ /*
+ * 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 */
hv_set_next_read_location(inring_info, next_read_location);
- spin_unlock_irqrestore(&inring_info->ring_lock, flags);
-
*signal = hv_need_to_signal_on_read(bytes_avail_towrite, inring_info);
- return 0;
+out_unlock:
+ spin_unlock_irqrestore(&inring_info->ring_lock, flags);
+ return ret;
}
projects / cascardo / linux.git / blobdiff