#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/hyperv.h>
+#include <linux/uio.h>
#include "hyperv_vmbus.h"
void hv_begin_read(struct hv_ring_buffer_info *rbi)
{
rbi->ring_buffer->interrupt_mask = 1;
- smp_mb();
+ mb();
}
u32 hv_end_read(struct hv_ring_buffer_info *rbi)
u32 write;
rbi->ring_buffer->interrupt_mask = 0;
- smp_mb();
+ mb();
/*
* Now check to see if the ring buffer is still empty.
static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi)
{
- smp_mb();
+ mb();
if (rbi->ring_buffer->interrupt_mask)
return false;
+ /* check interrupt_mask before read_index */
+ rmb();
/*
* This is the only case we need to signal when the
* ring transitions from being empty to non-empty.
* there is room for the producer to send the pending packet.
*/
-static bool hv_need_to_signal_on_read(u32 old_rd,
- struct hv_ring_buffer_info *rbi)
+static bool hv_need_to_signal_on_read(u32 prev_write_sz,
+ struct hv_ring_buffer_info *rbi)
{
- u32 prev_write_sz;
u32 cur_write_sz;
u32 r_size;
u32 write_loc = rbi->ring_buffer->write_index;
cur_write_sz = write_loc >= read_loc ? r_size - (write_loc - read_loc) :
read_loc - write_loc;
- prev_write_sz = write_loc >= old_rd ? r_size - (write_loc - old_rd) :
- old_rd - write_loc;
-
-
if ((prev_write_sz < pending_sz) && (cur_write_sz >= pending_sz))
return true;
ring_info->ring_buffer->read_index =
ring_info->ring_buffer->write_index = 0;
+ /*
+ * Set the feature bit for enabling flow control.
+ */
+ ring_info->ring_buffer->feature_bits.value = 1;
+
ring_info->ring_size = buflen;
ring_info->ring_datasize = buflen - sizeof(struct hv_ring_buffer);
*
*/
int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
- struct scatterlist *sglist, u32 sgcount, bool *signal)
+ struct kvec *kv_list, u32 kv_count, bool *signal)
{
int i = 0;
u32 bytes_avail_towrite;
u32 bytes_avail_toread;
u32 totalbytes_towrite = 0;
- struct scatterlist *sg;
u32 next_write_location;
u32 old_write;
u64 prev_indices = 0;
unsigned long flags;
- for_each_sg(sglist, sg, sgcount, i)
- {
- totalbytes_towrite += sg->length;
- }
+ for (i = 0; i < kv_count; i++)
+ totalbytes_towrite += kv_list[i].iov_len;
totalbytes_towrite += sizeof(u64);
old_write = next_write_location;
- for_each_sg(sglist, sg, sgcount, i)
- {
+ for (i = 0; i < kv_count; i++) {
next_write_location = hv_copyto_ringbuffer(outring_info,
next_write_location,
- sg_virt(sg),
- sg->length);
+ kv_list[i].iov_base,
+ kv_list[i].iov_len);
}
/* Set previous packet start */
sizeof(u64));
/* Issue a full memory barrier before updating the write index */
- smp_mb();
+ mb();
/* Now, update the write location */
hv_set_next_write_location(outring_info, next_write_location);
u32 next_read_location = 0;
u64 prev_indices = 0;
unsigned long flags;
- u32 old_read;
if (buflen <= 0)
return -EINVAL;
&bytes_avail_toread,
&bytes_avail_towrite);
- old_read = bytes_avail_toread;
-
/* Make sure there is something to read */
if (bytes_avail_toread < buflen) {
spin_unlock_irqrestore(&inring_info->ring_lock, flags);
/* 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 */
- smp_mb();
+ 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(old_read, inring_info);
+ *signal = hv_need_to_signal_on_read(bytes_avail_towrite, inring_info);
return 0;
}