vio: create routines for inc,dec vio dring indexes
Both sunvdc and sunvnet implemented distinct functionality for incrementing
and decrementing dring indexes. Create common functions for use by both
from the sunvnet versions, which were chosen since they will still work
correctly in case a non power of two ring size is used.
Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c
index 90c86cd..45c408e 100644
--- a/drivers/net/ethernet/sun/sunvnet.c
+++ b/drivers/net/ethernet/sun/sunvnet.c
@@ -466,23 +466,6 @@
return err;
}
-static u32 next_idx(u32 idx, struct vio_dring_state *dr)
-{
- if (++idx == dr->num_entries)
- idx = 0;
- return idx;
-}
-
-static u32 prev_idx(u32 idx, struct vio_dring_state *dr)
-{
- if (idx == 0)
- idx = dr->num_entries - 1;
- else
- idx--;
-
- return idx;
-}
-
static struct vio_net_desc *get_rx_desc(struct vnet_port *port,
struct vio_dring_state *dr,
u32 index)
@@ -556,7 +539,8 @@
int ack_start = -1, ack_end = -1;
bool send_ack = true;
- end = (end == (u32) -1) ? prev_idx(start, dr) : next_idx(end, dr);
+ end = (end == (u32) -1) ? vio_dring_prev(dr, start)
+ : vio_dring_next(dr, end);
viodbg(DATA, "vnet_walk_rx start[%08x] end[%08x]\n", start, end);
@@ -570,7 +554,7 @@
if (ack_start == -1)
ack_start = start;
ack_end = start;
- start = next_idx(start, dr);
+ start = vio_dring_next(dr, start);
if (ack && start != end) {
err = vnet_send_ack(port, dr, ack_start, ack_end,
VIO_DRING_ACTIVE);
@@ -584,7 +568,7 @@
}
}
if (unlikely(ack_start == -1))
- ack_start = ack_end = prev_idx(start, dr);
+ ack_start = ack_end = vio_dring_prev(dr, start);
if (send_ack) {
port->napi_resume = false;
return vnet_send_ack(port, dr, ack_start, ack_end,
@@ -633,7 +617,7 @@
found = 1;
break;
}
- idx = next_idx(idx, dr);
+ idx = vio_dring_next(dr, idx);
}
return found;
}
@@ -663,7 +647,7 @@
/* sync for race conditions with vnet_start_xmit() and tell xmit it
* is time to send a trigger.
*/
- dr->cons = next_idx(end, dr);
+ dr->cons = vio_dring_next(dr, end);
desc = vio_dring_entry(dr, dr->cons);
if (desc->hdr.state == VIO_DESC_READY && !port->start_cons) {
/* vnet_start_xmit() just populated this dring but missed
@@ -784,7 +768,7 @@
pkt->tag.stype = VIO_SUBTYPE_INFO;
pkt->tag.stype_env = VIO_DRING_DATA;
pkt->seq = dr->rcv_nxt;
- pkt->start_idx = next_idx(port->napi_stop_idx, dr);
+ pkt->start_idx = vio_dring_next(dr, port->napi_stop_idx);
pkt->end_idx = -1;
goto napi_resume;
}