bnxt_en: Do not adjust max_cp_rings by the ones used by RDMA.

Currently, the driver adjusts the bp->hw_resc.max_cp_rings by the number
of MSIX vectors used by RDMA.  There is one code path in open that needs
to check the true max_cp_rings including any used by RDMA.  This code
is now checking for the reduced max_cp_rings which will fail when the
number of cp rings is very small.

To fix this in a clean way, we don't adjust max_cp_rings anymore.
Instead, we add a helper bnxt_get_max_func_cp_rings_for_en() to get the
reduced max_cp_rings when appropriate.

Fixes: ec86f14ea506 ("bnxt_en: Add ULP calls to stop and restart IRQs.")
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 9 insertions, 12 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 6472ce447f87..cecbb1d1f587 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -5913,9 +5913,9 @@ unsigned int bnxt_get_max_func_cp_rings(struct bnxt *bp)
         return bp->hw_resc.max_cp_rings;
 }
 
-void bnxt_set_max_func_cp_rings(struct bnxt *bp, unsigned int max)
+unsigned int bnxt_get_max_func_cp_rings_for_en(struct bnxt *bp)
 {
-        bp->hw_resc.max_cp_rings = max;
+        return bp->hw_resc.max_cp_rings - bnxt_get_ulp_msix_num(bp);
 }
 
 static unsigned int bnxt_get_max_func_irqs(struct bnxt *bp)
@@ -8631,7 +8631,8 @@ static void _bnxt_get_max_rings(struct bnxt *bp, int *max_rx, int *max_tx,
 
         *max_tx = hw_resc->max_tx_rings;
         *max_rx = hw_resc->max_rx_rings;
-        *max_cp = min_t(int, hw_resc->max_irqs, hw_resc->max_cp_rings);
+        *max_cp = min_t(int, bnxt_get_max_func_cp_rings_for_en(bp),
+                        hw_resc->max_irqs);
         *max_cp = min_t(int, *max_cp, hw_resc->max_stat_ctxs);
         max_ring_grps = hw_resc->max_hw_ring_grps;
         if (BNXT_CHIP_TYPE_NITRO_A0(bp) && BNXT_PF(bp)) {
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index c4c77b9fa77b..bde384630a75 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -1481,7 +1481,7 @@ int bnxt_hwrm_set_coal(struct bnxt *);
 unsigned int bnxt_get_max_func_stat_ctxs(struct bnxt *bp);
 void bnxt_set_max_func_stat_ctxs(struct bnxt *bp, unsigned int max);
 unsigned int bnxt_get_max_func_cp_rings(struct bnxt *bp);
-void bnxt_set_max_func_cp_rings(struct bnxt *bp, unsigned int max);
+unsigned int bnxt_get_max_func_cp_rings_for_en(struct bnxt *bp);
 int bnxt_get_avail_msix(struct bnxt *bp, int num);
 int bnxt_reserve_rings(struct bnxt *bp);
 void bnxt_tx_disable(struct bnxt *bp);
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_sriov.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_sriov.c
index 6d583bcd2a81..fcd085a9853a 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_sriov.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_sriov.c
@@ -451,7 +451,7 @@ static int bnxt_hwrm_func_vf_resc_cfg(struct bnxt *bp, int num_vfs)
 
         bnxt_hwrm_cmd_hdr_init(bp, &req, HWRM_FUNC_VF_RESOURCE_CFG, -1, -1);
 
-        vf_cp_rings = hw_resc->max_cp_rings - bp->cp_nr_rings;
+        vf_cp_rings = bnxt_get_max_func_cp_rings_for_en(bp) - bp->cp_nr_rings;
         vf_stat_ctx = hw_resc->max_stat_ctxs - bp->num_stat_ctxs;
         if (bp->flags & BNXT_FLAG_AGG_RINGS)
                 vf_rx_rings = hw_resc->max_rx_rings - bp->rx_nr_rings * 2;
@@ -549,7 +549,8 @@ static int bnxt_hwrm_func_cfg(struct bnxt *bp, int num_vfs)
         max_stat_ctxs = hw_resc->max_stat_ctxs;
 
         /* Remaining rings are distributed equally amongs VF's for now */
-        vf_cp_rings = (hw_resc->max_cp_rings - bp->cp_nr_rings) / num_vfs;
+        vf_cp_rings = (bnxt_get_max_func_cp_rings_for_en(bp) -
+                       bp->cp_nr_rings) / num_vfs;
         vf_stat_ctx = (max_stat_ctxs - bp->num_stat_ctxs) / num_vfs;
         if (bp->flags & BNXT_FLAG_AGG_RINGS)
                 vf_rx_rings = (hw_resc->max_rx_rings - bp->rx_nr_rings * 2) /
@@ -643,7 +644,7 @@ static int bnxt_sriov_enable(struct bnxt *bp, int *num_vfs)
          */
         vfs_supported = *num_vfs;
 
-        avail_cp = hw_resc->max_cp_rings - bp->cp_nr_rings;
+        avail_cp = bnxt_get_max_func_cp_rings_for_en(bp) - bp->cp_nr_rings;
         avail_stat = hw_resc->max_stat_ctxs - bp->num_stat_ctxs;
         avail_cp = min_t(int, avail_cp, avail_stat);
 
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c
index deac73e8e0f7..beee61292d5e 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c
@@ -169,7 +169,6 @@ static int bnxt_req_msix_vecs(struct bnxt_en_dev *edev, int ulp_id,
                 edev->ulp_tbl[ulp_id].msix_requested = avail_msix;
         }
         bnxt_fill_msix_vecs(bp, ent);
-        bnxt_set_max_func_cp_rings(bp, max_cp_rings - avail_msix);
         edev->flags |= BNXT_EN_FLAG_MSIX_REQUESTED;
         return avail_msix;
 }
@@ -178,7 +177,6 @@ static int bnxt_free_msix_vecs(struct bnxt_en_dev *edev, int ulp_id)
 {
         struct net_device *dev = edev->net;
         struct bnxt *bp = netdev_priv(dev);
-        int max_cp_rings, msix_requested;
 
         ASSERT_RTNL();
         if (ulp_id != BNXT_ROCE_ULP)
@@ -187,9 +185,6 @@ static int bnxt_free_msix_vecs(struct bnxt_en_dev *edev, int ulp_id)
         if (!(edev->flags & BNXT_EN_FLAG_MSIX_REQUESTED))
                 return 0;
 
-        max_cp_rings = bnxt_get_max_func_cp_rings(bp);
-        msix_requested = edev->ulp_tbl[ulp_id].msix_requested;
-        bnxt_set_max_func_cp_rings(bp, max_cp_rings + msix_requested);
         edev->ulp_tbl[ulp_id].msix_requested = 0;
         edev->flags &= ~BNXT_EN_FLAG_MSIX_REQUESTED;
         if (netif_running(dev)) {