IB/hfi1: Add mtu check for operational data VLs

Since Virtual Lanes BCT credits and MTU are set through separate MADs, we
have to ensure both are valid, and data VLs are ready for transmission
before we allow port transition to Armed state.

Fixes: 5e2d676 ("IB/hfi1: Verify port data VLs credits on transition to Armed")
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Alex Estrin <alex.estrin@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/hfi1/chip.c

@@ -10558,12 +10558,29 @@ void set_link_down_reason(struct hfi1_pportdata *ppd, u8 lcl_reason,
 	}
 }
 
-/*
- * Verify if BCT for data VLs is non-zero.
+/**
+ * data_vls_operational() - Verify if data VL BCT credits and MTU
+ *			    are both set.
+ * @ppd: pointer to hfi1_pportdata structure
+ *
+ * Return: true - Ok, false -otherwise.
  */
 static inline bool data_vls_operational(struct hfi1_pportdata *ppd)
 {
-	return !!ppd->actual_vls_operational;
+	int i;
+	u64 reg;
+
+	if (!ppd->actual_vls_operational)
+		return false;
+
+	for (i = 0; i < ppd->vls_supported; i++) {
+		reg = read_csr(ppd->dd, SEND_CM_CREDIT_VL + (8 * i));
+		if ((reg && !ppd->dd->vld[i].mtu) ||
+		    (!reg && ppd->dd->vld[i].mtu))
+			return false;
+	}
+
+	return true;
 }
 
 /*
@@ -10675,7 +10692,8 @@ int set_link_state(struct hfi1_pportdata *ppd, u32 state)
 
 		if (!data_vls_operational(ppd)) {
 			dd_dev_err(dd,
-				   "%s: data VLs not operational\n", __func__);
+				   "%s: Invalid data VL credits or mtu\n",
+				   __func__);
 			ret = -EINVAL;
 			break;
 		}