bnx2x: Fix vlan credit issues for VFs

Starting with commit 2dc33bbc "bnx2x: Remove the sriov VFOP mechanism",
the bnx2x started enforcing vlan credits for all vlan configurations.
This exposed 2 issues:
  - Vlan credits are not returned once a VF is removed; this causes a leak
    of credits, and eventually will lead to VFs with no vlan credits.
  - A vlan credit must be set aside for the Hypervisor to use, and should
    not be visible to the VF.

Although linux VFs at the moment do not support vlan configuration [from the
VF side] which causes them to be resilient to this sort of issue, Windows VF
over linux hypervisors might fail to load as the vlan credits become depleted.

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 37 insertions, 11 deletions

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c
index 046c9cca0072..eefe8f528309 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c
@@ -427,7 +427,9 @@ static int bnx2x_vf_mac_vlan_config(struct bnx2x *bp,
         if (filter->add && filter->type == BNX2X_VF_FILTER_VLAN &&
             (atomic_read(&bnx2x_vfq(vf, qid, vlan_count)) >=
              vf_vlan_rules_cnt(vf))) {
-                BNX2X_ERR("No credits for vlan\n");
+                BNX2X_ERR("No credits for vlan [%d >= %d]\n",
+                          atomic_read(&bnx2x_vfq(vf, qid, vlan_count)),
+                          vf_vlan_rules_cnt(vf));
                 return -ENOMEM;
         }
 
@@ -837,6 +839,29 @@ int bnx2x_vf_flr_clnup_epilog(struct bnx2x *bp, u8 abs_vfid)
         return 0;
 }
 
+static void bnx2x_iov_re_set_vlan_filters(struct bnx2x *bp,
+                                          struct bnx2x_virtf *vf,
+                                          int new)
+{
+        int num = vf_vlan_rules_cnt(vf);
+        int diff = new - num;
+        bool rc = true;
+
+        DP(BNX2X_MSG_IOV, "vf[%d] - %d vlan filter credits [previously %d]\n",
+           vf->abs_vfid, new, num);
+
+        if (diff > 0)
+                rc = bp->vlans_pool.get(&bp->vlans_pool, diff);
+        else if (diff < 0)
+                rc = bp->vlans_pool.put(&bp->vlans_pool, -diff);
+
+        if (rc)
+                vf_vlan_rules_cnt(vf) = new;
+        else
+                DP(BNX2X_MSG_IOV, "vf[%d] - Failed to configure vlan filter credits change\n",
+                   vf->abs_vfid);
+}
+
 /* must be called after the number of PF queues and the number of VFs are
  * both known
  */
@@ -854,9 +879,11 @@ bnx2x_iov_static_resc(struct bnx2x *bp, struct bnx2x_virtf *vf)
         resc->num_mac_filters = 1;
 
         /* divvy up vlan rules */
+        bnx2x_iov_re_set_vlan_filters(bp, vf, 0);
         vlan_count = bp->vlans_pool.check(&bp->vlans_pool);
         vlan_count = 1 << ilog2(vlan_count);
-        resc->num_vlan_filters = vlan_count / BNX2X_NR_VIRTFN(bp);
+        bnx2x_iov_re_set_vlan_filters(bp, vf,
+                                      vlan_count / BNX2X_NR_VIRTFN(bp));
 
         /* no real limitation */
         resc->num_mc_filters = 0;
@@ -1478,10 +1505,6 @@ int bnx2x_iov_nic_init(struct bnx2x *bp)
                 bnx2x_iov_static_resc(bp, vf);
 
                 /* queues are initialized during VF-ACQUIRE */
-
-                /* reserve the vf vlan credit */
-                bp->vlans_pool.get(&bp->vlans_pool, vf_vlan_rules_cnt(vf));
-
                 vf->filter_state = 0;
                 vf->sp_cl_id = bnx2x_fp(bp, 0, cl_id);
 
@@ -1912,11 +1935,12 @@ int bnx2x_vf_chk_avail_resc(struct bnx2x *bp, struct bnx2x_virtf *vf,
         u8 rxq_cnt = vf_rxq_count(vf) ? : bnx2x_vf_max_queue_cnt(bp, vf);
         u8 txq_cnt = vf_txq_count(vf) ? : bnx2x_vf_max_queue_cnt(bp, vf);
 
+        /* Save a vlan filter for the Hypervisor */
         return ((req_resc->num_rxqs <= rxq_cnt) &&
                 (req_resc->num_txqs <= txq_cnt) &&
                 (req_resc->num_sbs <= vf_sb_count(vf))   &&
                 (req_resc->num_mac_filters <= vf_mac_rules_cnt(vf)) &&
-                (req_resc->num_vlan_filters <= vf_vlan_rules_cnt(vf)));
+                (req_resc->num_vlan_filters <= vf_vlan_rules_visible_cnt(vf)));
 }
 
 /* CORE VF API */
@@ -1972,14 +1996,14 @@ int bnx2x_vf_acquire(struct bnx2x *bp, struct bnx2x_virtf *vf,
         vf_txq_count(vf) = resc->num_txqs ? : bnx2x_vf_max_queue_cnt(bp, vf);
         if (resc->num_mac_filters)
                 vf_mac_rules_cnt(vf) = resc->num_mac_filters;
-        if (resc->num_vlan_filters)
-                vf_vlan_rules_cnt(vf) = resc->num_vlan_filters;
+        /* Add an additional vlan filter credit for the hypervisor */
+        bnx2x_iov_re_set_vlan_filters(bp, vf, resc->num_vlan_filters + 1);
 
         DP(BNX2X_MSG_IOV,
            "Fulfilling vf request: sb count %d, tx_count %d, rx_count %d, mac_rules_count %d, vlan_rules_count %d\n",
            vf_sb_count(vf), vf_rxq_count(vf),
            vf_txq_count(vf), vf_mac_rules_cnt(vf),
-           vf_vlan_rules_cnt(vf));
+           vf_vlan_rules_visible_cnt(vf));
 
         /* Initialize the queues */
         if (!vf->vfqs) {
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.h
index bb16c4b5c2af..6929adba52f9 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.h
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.h
@@ -159,6 +159,8 @@ struct bnx2x_virtf {
 #define vf_mac_rules_cnt(vf)            ((vf)->alloc_resc.num_mac_filters)
 #define vf_vlan_rules_cnt(vf)           ((vf)->alloc_resc.num_vlan_filters)
 #define vf_mc_rules_cnt(vf)             ((vf)->alloc_resc.num_mc_filters)
+        /* Hide a single vlan filter credit for the hypervisor */
+#define vf_vlan_rules_visible_cnt(vf)   (vf_vlan_rules_cnt(vf) - 1)
 
         u8 sb_count;    /* actual number of SBs */
         u8 igu_base_id; /* base igu status block id */
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c
index 0622884596b2..0c067e8564dd 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c
@@ -1163,7 +1163,7 @@ static void bnx2x_vf_mbx_acquire_resp(struct bnx2x *bp, struct bnx2x_virtf *vf,
                         bnx2x_vf_max_queue_cnt(bp, vf);
                 resc->num_sbs = vf_sb_count(vf);
                 resc->num_mac_filters = vf_mac_rules_cnt(vf);
-                resc->num_vlan_filters = vf_vlan_rules_cnt(vf);
+                resc->num_vlan_filters = vf_vlan_rules_visible_cnt(vf);
                 resc->num_mc_filters = 0;
 
                 if (status == PFVF_STATUS_SUCCESS) {