RDMA/bnxt_re: Enable atomics only if host bios supports

Driver shall check if the host system bios has enabled
Atomic operations capability in PCI Device Control 2
register of the pci-device. Expose the ATOMIC_HCA
flag only if the Atomic operations capability is set.

Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

3 files changed, 21 insertions, 2 deletions

diff --git a/drivers/infiniband/hw/bnxt_re/ib_verbs.c b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
index 4d3cdca03c02..7b17030d2696 100644
--- a/drivers/infiniband/hw/bnxt_re/ib_verbs.c
+++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
@@ -173,8 +173,10 @@ int bnxt_re_query_device(struct ib_device *ibdev,
         ib_attr->max_pd = dev_attr->max_pd;
         ib_attr->max_qp_rd_atom = dev_attr->max_qp_rd_atom;
         ib_attr->max_qp_init_rd_atom = dev_attr->max_qp_init_rd_atom;
-        ib_attr->atomic_cap = IB_ATOMIC_HCA;
-        ib_attr->masked_atomic_cap = IB_ATOMIC_HCA;
+        if (dev_attr->is_atomic) {
+                ib_attr->atomic_cap = IB_ATOMIC_HCA;
+                ib_attr->masked_atomic_cap = IB_ATOMIC_HCA;
+        }
 
         ib_attr->max_ee_rd_atom = 0;
         ib_attr->max_res_rd_atom = 0;
diff --git a/drivers/infiniband/hw/bnxt_re/qplib_sp.c b/drivers/infiniband/hw/bnxt_re/qplib_sp.c
index 5827573875d4..ef91ab786dd4 100644
--- a/drivers/infiniband/hw/bnxt_re/qplib_sp.c
+++ b/drivers/infiniband/hw/bnxt_re/qplib_sp.c
@@ -51,6 +51,19 @@ const struct bnxt_qplib_gid bnxt_qplib_gid_zero = {{ 0, 0, 0, 0, 0, 0, 0, 0,
                                                      0, 0, 0, 0, 0, 0, 0, 0 } };
 
 /* Device */
+
+static bool bnxt_qplib_is_atomic_cap(struct bnxt_qplib_rcfw *rcfw)
+{
+        int rc;
+        u16 pcie_ctl2;
+
+        rc = pcie_capability_read_word(rcfw->pdev, PCI_EXP_DEVCTL2,
+                                       &pcie_ctl2);
+        if (rc)
+                return false;
+        return !!(pcie_ctl2 & PCI_EXP_DEVCTL2_ATOMIC_REQ);
+}
+
 int bnxt_qplib_get_dev_attr(struct bnxt_qplib_rcfw *rcfw,
                             struct bnxt_qplib_dev_attr *attr)
 {
@@ -131,6 +144,7 @@ int bnxt_qplib_get_dev_attr(struct bnxt_qplib_rcfw *rcfw,
                 attr->tqm_alloc_reqs[i * 4 + 3] = *(++tqm_alloc);
         }
 
+        attr->is_atomic = bnxt_qplib_is_atomic_cap(rcfw);
 bail:
         bnxt_qplib_rcfw_free_sbuf(rcfw, sbuf);
         return rc;
diff --git a/drivers/infiniband/hw/bnxt_re/qplib_sp.h b/drivers/infiniband/hw/bnxt_re/qplib_sp.h
index a543f959098b..2ce7e2a32cf0 100644
--- a/drivers/infiniband/hw/bnxt_re/qplib_sp.h
+++ b/drivers/infiniband/hw/bnxt_re/qplib_sp.h
@@ -42,6 +42,8 @@
 
 #define BNXT_QPLIB_RESERVED_QP_WRS      128
 
+#define PCI_EXP_DEVCTL2_ATOMIC_REQ      0x0040
+
 struct bnxt_qplib_dev_attr {
         char                            fw_ver[32];
         u16                             max_sgid;
@@ -70,6 +72,7 @@ struct bnxt_qplib_dev_attr {
         u32                             max_inline_data;
         u32                             l2_db_size;
         u8                              tqm_alloc_reqs[MAX_TQM_ALLOC_REQ];
+        bool                            is_atomic;
 };
 
 struct bnxt_qplib_pd {