be2net: SRIOV Queue distribution should factor in EQ-count of VFs

The SRIOV resource distribution logic for RX/TX queue counts is not optimal
when a small number of VFs are enabled. It does not take into account the
VF's EQ count while computing the queue counts. Because of this, the VF
gets a large number of queues, though it doesn't have sufficient EQs,
resulting in wasted queue resources. And the PF gets a smaller share of
queues though it has more EQs. Fix this by capping the VF queue count at
its EQ count.

Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/emulex/benet/be.h b/drivers/net/ethernet/emulex/benet/be.h
index cf83783..de88c30 100644 (file)
--- a/drivers/net/ethernet/emulex/benet/be.h
+++ b/drivers/net/ethernet/emulex/benet/be.h
@@ -89,6 +89,10 @@
 #define BE3_MAX_TX_QS          16
 #define BE3_MAX_EVT_QS         16
 #define BE3_SRIOV_MAX_EVT_QS   8
 #define BE3_MAX_TX_QS          16
 #define BE3_MAX_EVT_QS         16
 #define BE3_SRIOV_MAX_EVT_QS   8

+#define SH_VF_MAX_NIC_EQS      3       /* Skyhawk VFs can have a max of 4 EQs
+                                        * and at least 1 is granted to either
+                                        * SURF/DPDK
+                                        */

 
 #define MAX_RSS_IFACES         15
 #define MAX_RX_QS              32
 
 #define MAX_RSS_IFACES         15
 #define MAX_RX_QS              32

diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index 09e6f2c..62f6fbb 100644 (file)
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -3792,18 +3792,15 @@ static u16 be_calculate_vf_qs(struct be_adapter *adapter, u16 num_vfs)
        struct be_resources res = adapter->pool_res;
        u16 num_vf_qs = 1;
 
        struct be_resources res = adapter->pool_res;
        u16 num_vf_qs = 1;
 

-       /* Distribute the queue resources equally among the PF and it's VFs
+       /* Distribute the queue resources among the PF and it's VFs

         * Do not distribute queue resources in multi-channel configuration.
         */
        if (num_vfs && !be_is_mc(adapter)) {
         * Do not distribute queue resources in multi-channel configuration.
         */
        if (num_vfs && !be_is_mc(adapter)) {

-               /* If number of VFs requested is 8 less than max supported,
-                * assign 8 queue pairs to the PF and divide the remaining
-                * resources evenly among the VFs
-                */
-               if (num_vfs < (be_max_vfs(adapter) - 8))
-                       num_vf_qs = (res.max_rss_qs - 8) / num_vfs;
-               else
-                       num_vf_qs = res.max_rss_qs / num_vfs;
+                /* Divide the qpairs evenly among the VFs and the PF, capped
+                 * at VF-EQ-count. Any remainder qpairs belong to the PF.
+                 */
+               num_vf_qs = min(SH_VF_MAX_NIC_EQS,
+                               res.max_rss_qs / (num_vfs + 1));

 
                /* Skyhawk-R chip supports only MAX_RSS_IFACES RSS capable
                 * interfaces per port. Provide RSS on VFs, only if number
 
                /* Skyhawk-R chip supports only MAX_RSS_IFACES RSS capable
                 * interfaces per port. Provide RSS on VFs, only if number