DCB: Add support for DCB BCN
Adds an interface to configure the Backward Congestion Notification
(BCN) feature. In a BCN capabale network, congestion notifications
from congested points out in the network can cause the end station
limit the rate of a given traffic flow.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ixgbe/ixgbe_dcb.h b/drivers/net/ixgbe/ixgbe_dcb.h
index 62dfd243..75f6efe 100644
--- a/drivers/net/ixgbe/ixgbe_dcb.h
+++ b/drivers/net/ixgbe/ixgbe_dcb.h
@@ -108,7 +108,34 @@
pba_80_48 /* PBA[0-3] each use 80KB, PBA[4-7] each use 48KB */
};
+/*
+ * This structure contains many values encoded as fixed-point
+ * numbers, meaning that some of bits are dedicated to the
+ * magnitude and others to the fraction part. In the comments
+ * this is shown as f=n, where n is the number of fraction bits.
+ * These fraction bits are always the low-order bits. The size
+ * of the magnitude is not specified.
+ */
+struct bcn_config {
+ u32 rp_admin_mode[MAX_TRAFFIC_CLASS]; /* BCN enabled, per TC */
+ u32 bcna_option[2]; /* BCNA Port + MAC Addr */
+ u32 rp_w; /* Derivative Weight, f=3 */
+ u32 rp_gi; /* Increase Gain, f=12 */
+ u32 rp_gd; /* Decrease Gain, f=12 */
+ u32 rp_ru; /* Rate Unit */
+ u32 rp_alpha; /* Max Decrease Factor, f=12 */
+ u32 rp_beta; /* Max Increase Factor, f=12 */
+ u32 rp_ri; /* Initial Rate */
+ u32 rp_td; /* Drift Interval Timer */
+ u32 rp_rd; /* Drift Increase */
+ u32 rp_tmax; /* Severe Congestion Backoff Timer Range */
+ u32 rp_rmin; /* Severe Congestion Restart Rate */
+ u32 rp_wrtt; /* RTT Moving Average Weight */
+};
+
struct ixgbe_dcb_config {
+ struct bcn_config bcn;
+
struct tc_configuration tc_config[MAX_TRAFFIC_CLASS];
u8 bw_percentage[2][MAX_BW_GROUP]; /* One each for Tx/Rx */