qed: VFs to try utilizing the doorbell bar

VFs are currently not mapping their doorbell bar, instead relying
on the small doorbell window they have in their limited regview bar.

In order to increase the number of possible Tx connections [queues]
employeed by VF past 16, we need to start using the doorbell bar if
one such is exposed - VF would communicate this fact to PF which would
return the size-bar internally configured into chip, according to
which the VF would decide whether to actually utilize the doorbell
bar.

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

1 files changed, 128 insertions, 53 deletions

diff --git a/drivers/net/ethernet/qlogic/qed/qed_vf.c b/drivers/net/ethernet/qlogic/qed/qed_vf.c
index c0d2febad86a..cb81c357bf62 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_vf.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_vf.c
@@ -169,6 +169,61 @@ static void qed_vf_pf_add_qid(struct qed_hwfn *p_hwfn,
 	p_qid_tlv->qid = p_cid->qid_usage_idx;
 }
 
+int _qed_vf_pf_release(struct qed_hwfn *p_hwfn, bool b_final)
+{
+	struct qed_vf_iov *p_iov = p_hwfn->vf_iov_info;
+	struct pfvf_def_resp_tlv *resp;
+	struct vfpf_first_tlv *req;
+	u32 size;
+	int rc;
+
+	/* clear mailbox and prep first tlv */
+	req = qed_vf_pf_prep(p_hwfn, CHANNEL_TLV_RELEASE, sizeof(*req));
+
+	/* add list termination tlv */
+	qed_add_tlv(p_hwfn, &p_iov->offset,
+		    CHANNEL_TLV_LIST_END, sizeof(struct channel_list_end_tlv));
+
+	resp = &p_iov->pf2vf_reply->default_resp;
+	rc = qed_send_msg2pf(p_hwfn, &resp->hdr.status, sizeof(*resp));
+
+	if (!rc && resp->hdr.status != PFVF_STATUS_SUCCESS)
+		rc = -EAGAIN;
+
+	qed_vf_pf_req_end(p_hwfn, rc);
+	if (!b_final)
+		return rc;
+
+	p_hwfn->b_int_enabled = 0;
+
+	if (p_iov->vf2pf_request)
+		dma_free_coherent(&p_hwfn->cdev->pdev->dev,
+				  sizeof(union vfpf_tlvs),
+				  p_iov->vf2pf_request,
+				  p_iov->vf2pf_request_phys);
+	if (p_iov->pf2vf_reply)
+		dma_free_coherent(&p_hwfn->cdev->pdev->dev,
+				  sizeof(union pfvf_tlvs),
+				  p_iov->pf2vf_reply, p_iov->pf2vf_reply_phys);
+
+	if (p_iov->bulletin.p_virt) {
+		size = sizeof(struct qed_bulletin_content);
+		dma_free_coherent(&p_hwfn->cdev->pdev->dev,
+				  size,
+				  p_iov->bulletin.p_virt, p_iov->bulletin.phys);
+	}
+
+	kfree(p_hwfn->vf_iov_info);
+	p_hwfn->vf_iov_info = NULL;
+
+	return rc;
+}
+
+int qed_vf_pf_release(struct qed_hwfn *p_hwfn)
+{
+	return _qed_vf_pf_release(p_hwfn, true);
+}
+
 #define VF_ACQUIRE_THRESH 3
 static void qed_vf_pf_acquire_reduce_resc(struct qed_hwfn *p_hwfn,
 					  struct vf_pf_resc_request *p_req,
@@ -235,6 +290,11 @@ static int qed_vf_pf_acquire(struct qed_hwfn *p_hwfn)
 	/* Fill capability field with any non-deprecated config we support */
 	req->vfdev_info.capabilities |= VFPF_ACQUIRE_CAP_100G;
 
+	/* If we've mapped the doorbell bar, try using queue qids */
+	if (p_iov->b_doorbell_bar)
+		req->vfdev_info.capabilities |= VFPF_ACQUIRE_CAP_PHYSICAL_BAR |
+						VFPF_ACQUIRE_CAP_QUEUE_QIDS;
+
 	/* pf 2 vf bulletin board address */
 	req->bulletin_addr = p_iov->bulletin.phys;
 	req->bulletin_size = p_iov->bulletin.size;
@@ -364,10 +424,27 @@ exit:
 	return rc;
 }
 
+u32 qed_vf_hw_bar_size(struct qed_hwfn *p_hwfn, enum BAR_ID bar_id)
+{
+	u32 bar_size;
+
+	/* Regview size is fixed */
+	if (bar_id == BAR_ID_0)
+		return 1 << 17;
+
+	/* Doorbell is received from PF */
+	bar_size = p_hwfn->vf_iov_info->acquire_resp.pfdev_info.bar_size;
+	if (bar_size)
+		return 1 << bar_size;
+	return 0;
+}
+
 int qed_vf_hw_prepare(struct qed_hwfn *p_hwfn)
 {
+	struct qed_hwfn *p_lead = QED_LEADING_HWFN(p_hwfn->cdev);
 	struct qed_vf_iov *p_iov;
 	u32 reg;
+	int rc;
 
 	/* Set number of hwfns - might be overriden once leading hwfn learns
 	 * actual configuration from PF.
@@ -375,10 +452,6 @@ int qed_vf_hw_prepare(struct qed_hwfn *p_hwfn)
 	if (IS_LEAD_HWFN(p_hwfn))
 		p_hwfn->cdev->num_hwfns = 1;
 
-	/* Set the doorbell bar. Assumption: regview is set */
-	p_hwfn->doorbells = (u8 __iomem *)p_hwfn->regview +
-					  PXP_VF_BAR0_START_DQ;
-
 	reg = PXP_VF_BAR0_ME_OPAQUE_ADDRESS;
 	p_hwfn->hw_info.opaque_fid = (u16)REG_RD(p_hwfn, reg);
 
@@ -390,6 +463,30 @@ int qed_vf_hw_prepare(struct qed_hwfn *p_hwfn)
 	if (!p_iov)
 		return -ENOMEM;
 
+	/* Doorbells are tricky; Upper-layer has alreday set the hwfn doorbell
+	 * value, but there are several incompatibily scenarios where that
+	 * would be incorrect and we'd need to override it.
+	 */
+	if (!p_hwfn->doorbells) {
+		p_hwfn->doorbells = (u8 __iomem *)p_hwfn->regview +
+						  PXP_VF_BAR0_START_DQ;
+	} else if (p_hwfn == p_lead) {
+		/* For leading hw-function, value is always correct, but need
+		 * to handle scenario where legacy PF would not support 100g
+		 * mapped bars later.
+		 */
+		p_iov->b_doorbell_bar = true;
+	} else {
+		/* here, value would be correct ONLY if the leading hwfn
+		 * received indication that mapped-bars are supported.
+		 */
+		if (p_lead->vf_iov_info->b_doorbell_bar)
+			p_iov->b_doorbell_bar = true;
+		else
+			p_hwfn->doorbells = (u8 __iomem *)
+			    p_hwfn->regview + PXP_VF_BAR0_START_DQ;
+	}
+
 	/* Allocate vf2pf msg */
 	p_iov->vf2pf_request = dma_alloc_coherent(&p_hwfn->cdev->pdev->dev,
 						  sizeof(union vfpf_tlvs),
@@ -429,7 +526,33 @@ int qed_vf_hw_prepare(struct qed_hwfn *p_hwfn)
 
 	p_hwfn->hw_info.personality = QED_PCI_ETH;
 
-	return qed_vf_pf_acquire(p_hwfn);
+	rc = qed_vf_pf_acquire(p_hwfn);
+
+	/* If VF is 100g using a mapped bar and PF is too old to support that,
+	 * acquisition would succeed - but the VF would have no way knowing
+	 * the size of the doorbell bar configured in HW and thus will not
+	 * know how to split it for 2nd hw-function.
+	 * In this case we re-try without the indication of the mapped
+	 * doorbell.
+	 */
+	if (!rc && p_iov->b_doorbell_bar &&
+	    !qed_vf_hw_bar_size(p_hwfn, BAR_ID_1) &&
+	    (p_hwfn->cdev->num_hwfns > 1)) {
+		rc = _qed_vf_pf_release(p_hwfn, false);
+		if (rc)
+			return rc;
+
+		p_iov->b_doorbell_bar = false;
+		p_hwfn->doorbells = (u8 __iomem *)p_hwfn->regview +
+						  PXP_VF_BAR0_START_DQ;
+		rc = qed_vf_pf_acquire(p_hwfn);
+	}
+
+	DP_VERBOSE(p_hwfn, QED_MSG_IOV,
+		   "Regview [%p], Doorbell [%p], Device-doorbell [%p]\n",
+		   p_hwfn->regview, p_hwfn->doorbells, p_hwfn->cdev->doorbells);
+
+	return rc;
 
 free_vf2pf_request:
 	dma_free_coherent(&p_hwfn->cdev->pdev->dev,
@@ -1133,54 +1256,6 @@ exit:
 	return rc;
 }
 
-int qed_vf_pf_release(struct qed_hwfn *p_hwfn)
-{
-	struct qed_vf_iov *p_iov = p_hwfn->vf_iov_info;
-	struct pfvf_def_resp_tlv *resp;
-	struct vfpf_first_tlv *req;
-	u32 size;
-	int rc;
-
-	/* clear mailbox and prep first tlv */
-	req = qed_vf_pf_prep(p_hwfn, CHANNEL_TLV_RELEASE, sizeof(*req));
-
-	/* add list termination tlv */
-	qed_add_tlv(p_hwfn, &p_iov->offset,
-		    CHANNEL_TLV_LIST_END, sizeof(struct channel_list_end_tlv));
-
-	resp = &p_iov->pf2vf_reply->default_resp;
-	rc = qed_send_msg2pf(p_hwfn, &resp->hdr.status, sizeof(*resp));
-
-	if (!rc && resp->hdr.status != PFVF_STATUS_SUCCESS)
-		rc = -EAGAIN;
-
-	qed_vf_pf_req_end(p_hwfn, rc);
-
-	p_hwfn->b_int_enabled = 0;
-
-	if (p_iov->vf2pf_request)
-		dma_free_coherent(&p_hwfn->cdev->pdev->dev,
-				  sizeof(union vfpf_tlvs),
-				  p_iov->vf2pf_request,
-				  p_iov->vf2pf_request_phys);
-	if (p_iov->pf2vf_reply)
-		dma_free_coherent(&p_hwfn->cdev->pdev->dev,
-				  sizeof(union pfvf_tlvs),
-				  p_iov->pf2vf_reply, p_iov->pf2vf_reply_phys);
-
-	if (p_iov->bulletin.p_virt) {
-		size = sizeof(struct qed_bulletin_content);
-		dma_free_coherent(&p_hwfn->cdev->pdev->dev,
-				  size,
-				  p_iov->bulletin.p_virt, p_iov->bulletin.phys);
-	}
-
-	kfree(p_hwfn->vf_iov_info);
-	p_hwfn->vf_iov_info = NULL;
-
-	return rc;
-}
-
 void qed_vf_pf_filter_mcast(struct qed_hwfn *p_hwfn,
 			    struct qed_filter_mcast *p_filter_cmd)
 {