RDMA/bnxt_re: Enable global atomic ops if platform supports

Enabling Atomic operations for Gen P5 devices if the underlying platform
supports global atomic ops.

Link: https://lore.kernel.org/r/20210603131534.982257-2-devesh.sharma@broadcom.com
Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/bnxt_re/ib_verbs.c

@@ -163,6 +163,10 @@ int bnxt_re_query_device(struct ib_device *ibdev,
 	ib_attr->max_qp_init_rd_atom = dev_attr->max_qp_init_rd_atom;
 	ib_attr->atomic_cap = IB_ATOMIC_NONE;
 	ib_attr->masked_atomic_cap = IB_ATOMIC_NONE;
+	if (dev_attr->is_atomic) {
+		ib_attr->atomic_cap = IB_ATOMIC_GLOB;
+		ib_attr->masked_atomic_cap = IB_ATOMIC_GLOB;
+	}
 
 	ib_attr->max_ee_rd_atom = 0;
 	ib_attr->max_res_rd_atom = 0;

drivers/infiniband/hw/bnxt_re/main.c

@@ -128,6 +128,9 @@ static int bnxt_re_setup_chip_ctx(struct bnxt_re_dev *rdev, u8 wqe_mode)
 	rdev->rcfw.res = &rdev->qplib_res;
 
 	bnxt_re_set_drv_mode(rdev, wqe_mode);
+	if (bnxt_qplib_determine_atomics(en_dev->pdev))
+		ibdev_info(&rdev->ibdev,
+			   "platform doesn't support global atomics.");
 	return 0;
 }
 

drivers/infiniband/hw/bnxt_re/qplib_res.c

@@ -959,3 +959,20 @@ int bnxt_qplib_alloc_res(struct bnxt_qplib_res *res, struct pci_dev *pdev,
 	bnxt_qplib_free_res(res);
 	return rc;
 }
+
+int bnxt_qplib_determine_atomics(struct pci_dev *dev)
+{
+	int comp;
+	u16 ctl2;
+
+	comp = pci_enable_atomic_ops_to_root(dev,
+					     PCI_EXP_DEVCAP2_ATOMIC_COMP32);
+	if (comp)
+		return -EOPNOTSUPP;
+	comp = pci_enable_atomic_ops_to_root(dev,
+					     PCI_EXP_DEVCAP2_ATOMIC_COMP64);
+	if (comp)
+		return -EOPNOTSUPP;
+	pcie_capability_read_word(dev, PCI_EXP_DEVCTL2, &ctl2);
+	return !(ctl2 & PCI_EXP_DEVCTL2_ATOMIC_REQ);
+}

drivers/infiniband/hw/bnxt_re/qplib_res.h

@@ -373,6 +373,7 @@ void bnxt_qplib_free_ctx(struct bnxt_qplib_res *res,
 int bnxt_qplib_alloc_ctx(struct bnxt_qplib_res *res,
 			 struct bnxt_qplib_ctx *ctx,
 			 bool virt_fn, bool is_p5);
+int bnxt_qplib_determine_atomics(struct pci_dev *dev);
 
 static inline void bnxt_qplib_hwq_incr_prod(struct bnxt_qplib_hwq *hwq, u32 cnt)
 {

drivers/infiniband/hw/bnxt_re/qplib_sp.c

@@ -54,6 +54,17 @@ const struct bnxt_qplib_gid bnxt_qplib_gid_zero = {{ 0, 0, 0, 0, 0, 0, 0, 0,
 
 /* Device */
 
+static bool bnxt_qplib_is_atomic_cap(struct bnxt_qplib_rcfw *rcfw)
+{
+	u16 pcie_ctl2 = 0;
+
+	if (!bnxt_qplib_is_chip_gen_p5(rcfw->res->cctx))
+		return false;
+
+	pcie_capability_read_word(rcfw->pdev, PCI_EXP_DEVCTL2, &pcie_ctl2);
+	return (pcie_ctl2 & PCI_EXP_DEVCTL2_ATOMIC_REQ);
+}
+
 static void bnxt_qplib_query_version(struct bnxt_qplib_rcfw *rcfw,
 				     char *fw_ver)
 {
@@ -162,7 +173,7 @@ int bnxt_qplib_get_dev_attr(struct bnxt_qplib_rcfw *rcfw,
 		attr->tqm_alloc_reqs[i * 4 + 3] = *(++tqm_alloc);
 	}
 
-	attr->is_atomic = false;
+	attr->is_atomic = bnxt_qplib_is_atomic_cap(rcfw);
 bail:
 	bnxt_qplib_rcfw_free_sbuf(rcfw, sbuf);
 	return rc;

drivers/infiniband/hw/bnxt_re/qplib_sp.h

@@ -42,8 +42,6 @@
 
 #define BNXT_QPLIB_RESERVED_QP_WRS	128
 
-#define PCI_EXP_DEVCTL2_ATOMIC_REQ      0x0040
-
 struct bnxt_qplib_dev_attr {
 #define FW_VER_ARR_LEN			4
 	u8				fw_ver[FW_VER_ARR_LEN];