octeontx2-af: Enable sriov on AF to create VFs

Enable all AF VFs during probe. Since AF's VFs work in pairs
(eg: Pkts sent on VF0 are received by VF1 and viceversa),
enable only even number of VFs out of totalVFs, which should
again be less than number of loopback (LBK) channels.

Also enable VF's mailbox interrupts.
Signed-off-by: Tomasz Duszynski <tduszynski@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/octeontx2/af/rvu.c

@@ -1698,7 +1698,7 @@ static void rvu_queue_work(struct mbox_wq_info *mw, int first,
 static irqreturn_t rvu_mbox_intr_handler(int irq, void *rvu_irq)
 {
 	struct rvu *rvu = (struct rvu *)rvu_irq;
-	int vfs = pci_num_vf(rvu->pdev);
+	int vfs = rvu->vfs;
 	u64 intr;
 
 	intr = rvu_read64(rvu, BLKADDR_RVUM, RVU_AF_PFAF_MBOX_INT);
@@ -1858,9 +1858,25 @@ static void rvu_unregister_interrupts(struct rvu *rvu)
 	rvu->num_vec = 0;
 }
 
+static int rvu_afvf_msix_vectors_num_ok(struct rvu *rvu)
+{
+	struct rvu_pfvf *pfvf = &rvu->pf[0];
+	int offset;
+
+	pfvf = &rvu->pf[0];
+	offset = rvu_read64(rvu, BLKADDR_RVUM, RVU_PRIV_PFX_INT_CFG(0)) & 0x3ff;
+
+	/* Make sure there are enough MSIX vectors configured so that
+	 * VF interrupts can be handled. Offset equal to zero means
+	 * that PF vectors are not configured and overlapping AF vectors.
+	 */
+	return (pfvf->msix.max >= RVU_AF_INT_VEC_CNT + RVU_PF_INT_VEC_CNT) &&
+	       offset;
+}
+
 static int rvu_register_interrupts(struct rvu *rvu)
 {
-	int ret;
+	int ret, offset;
 
 	rvu->num_vec = pci_msix_vec_count(rvu->pdev);
 
@@ -1921,6 +1937,40 @@ static int rvu_register_interrupts(struct rvu *rvu)
 	rvu_write64(rvu, BLKADDR_RVUM, RVU_AF_PFFLR_INT_ENA_W1S,
 		    INTR_MASK(rvu->hw->total_pfs) & ~1ULL);
 
+	if (!rvu_afvf_msix_vectors_num_ok(rvu))
+		return 0;
+
+	/* Get PF MSIX vectors offset. */
+	offset = rvu_read64(rvu, BLKADDR_RVUM, RVU_PRIV_PFX_INT_CFG(0)) & 0x3ff;
+
+	/* Register MBOX0 interrupt. */
+	offset += RVU_PF_INT_VEC_VFPF_MBOX0;
+	sprintf(&rvu->irq_name[offset * NAME_SIZE], "RVUAFVF Mbox0");
+	ret = request_irq(pci_irq_vector(rvu->pdev, offset),
+			  rvu_mbox_intr_handler, 0,
+			  &rvu->irq_name[offset * NAME_SIZE],
+			  rvu);
+	if (ret)
+		dev_err(rvu->dev,
+			"RVUAF: IRQ registration failed for Mbox0\n");
+
+	rvu->irq_allocated[offset] = true;
+
+	/* Register MBOX1 interrupt. MBOX1 IRQ number follows MBOX0 so
+	 * simply increment current offset by 1.
+	 */
+	offset += 1;
+	sprintf(&rvu->irq_name[offset * NAME_SIZE], "RVUAFVF Mbox1");
+	ret = request_irq(pci_irq_vector(rvu->pdev, offset),
+			  rvu_mbox_intr_handler, 0,
+			  &rvu->irq_name[offset * NAME_SIZE],
+			  rvu);
+	if (ret)
+		dev_err(rvu->dev,
+			"RVUAF: IRQ registration failed for Mbox1\n");
+
+	rvu->irq_allocated[offset] = true;
+
 	return 0;
 
 fail:
@@ -1973,6 +2023,129 @@ static int rvu_flr_init(struct rvu *rvu)
 	return 0;
 }
 
+static void rvu_disable_afvf_mbox_intr(struct rvu *rvu)
+{
+	int vfs = rvu->vfs;
+
+	rvupf_write64(rvu, RVU_PF_VFPF_MBOX_INT_ENA_W1CX(0), INTR_MASK(vfs));
+	if (vfs > 64)
+		rvupf_write64(rvu, RVU_PF_VFPF_MBOX_INT_ENA_W1CX(1),
+			      INTR_MASK(vfs - 64));
+}
+
+static void rvu_enable_afvf_mbox_intr(struct rvu *rvu)
+{
+	int vfs = rvu->vfs;
+
+	/* Clear any pending interrupts and enable AF VF interrupts for
+	 * the first 64 VFs.
+	 */
+	rvupf_write64(rvu, RVU_PF_VFPF_MBOX_INTX(0), INTR_MASK(vfs));
+	rvupf_write64(rvu, RVU_PF_VFPF_MBOX_INT_ENA_W1SX(0), INTR_MASK(vfs));
+
+	/* Same for remaining VFs, if any. */
+	if (vfs <= 64)
+		return;
+
+	rvupf_write64(rvu, RVU_PF_VFPF_MBOX_INTX(1), INTR_MASK(vfs - 64));
+	rvupf_write64(rvu, RVU_PF_VFPF_MBOX_INT_ENA_W1SX(1),
+		      INTR_MASK(vfs - 64));
+}
+
+#define PCI_DEVID_OCTEONTX2_LBK 0xA061
+
+static int lbk_get_num_chans(void)
+{
+	struct pci_dev *pdev;
+	void __iomem *base;
+	int ret = -EIO;
+
+	pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM, PCI_DEVID_OCTEONTX2_LBK,
+			      NULL);
+	if (!pdev)
+		goto err;
+
+	base = pci_ioremap_bar(pdev, 0);
+	if (!base)
+		goto err_put;
+
+	/* Read number of available LBK channels from LBK(0)_CONST register. */
+	ret = (readq(base + 0x10) >> 32) & 0xffff;
+	iounmap(base);
+err_put:
+	pci_dev_put(pdev);
+err:
+	return ret;
+}
+
+static int rvu_enable_sriov(struct rvu *rvu)
+{
+	struct pci_dev *pdev = rvu->pdev;
+	int err, chans, vfs;
+
+	if (!rvu_afvf_msix_vectors_num_ok(rvu)) {
+		dev_warn(&pdev->dev,
+			 "Skipping SRIOV enablement since not enough IRQs are available\n");
+		return 0;
+	}
+
+	chans = lbk_get_num_chans();
+	if (chans < 0)
+		return chans;
+
+	vfs = pci_sriov_get_totalvfs(pdev);
+
+	/* Limit VFs in case we have more VFs than LBK channels available. */
+	if (vfs > chans)
+		vfs = chans;
+
+	/* AF's VFs work in pairs and talk over consecutive loopback channels.
+	 * Thus we want to enable maximum even number of VFs. In case
+	 * odd number of VFs are available then the last VF on the list
+	 * remains disabled.
+	 */
+	if (vfs & 0x1) {
+		dev_warn(&pdev->dev,
+			 "Number of VFs should be even. Enabling %d out of %d.\n",
+			 vfs - 1, vfs);
+		vfs--;
+	}
+
+	if (!vfs)
+		return 0;
+
+	/* Save VFs number for reference in VF interrupts handlers.
+	 * Since interrupts might start arriving during SRIOV enablement
+	 * ordinary API cannot be used to get number of enabled VFs.
+	 */
+	rvu->vfs = vfs;
+
+	err = rvu_mbox_init(rvu, &rvu->afvf_wq_info, TYPE_AFVF, vfs,
+			    rvu_afvf_mbox_handler, rvu_afvf_mbox_up_handler);
+	if (err)
+		return err;
+
+	rvu_enable_afvf_mbox_intr(rvu);
+	/* Make sure IRQs are enabled before SRIOV. */
+	mb();
+
+	err = pci_enable_sriov(pdev, vfs);
+	if (err) {
+		rvu_disable_afvf_mbox_intr(rvu);
+		rvu_mbox_destroy(&rvu->afvf_wq_info);
+		return err;
+	}
+
+	return 0;
+}
+
+static void rvu_disable_sriov(struct rvu *rvu)
+{
+	rvu_disable_afvf_mbox_intr(rvu);
+	rvu_mbox_destroy(&rvu->afvf_wq_info);
+	pci_disable_sriov(rvu->pdev);
+}
+
 static int rvu_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct device *dev = &pdev->dev;
@@ -2054,7 +2227,14 @@ static int rvu_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (err)
 		goto err_flr;
 
+	/* Enable AF's VFs (if any) */
+	err = rvu_enable_sriov(rvu);
+	if (err)
+		goto err_irq;
+
 	return 0;
+err_irq:
+	rvu_unregister_interrupts(rvu);
 err_flr:
 	rvu_flr_wq_destroy(rvu);
 err_cgx:
@@ -2083,6 +2263,7 @@ static void rvu_remove(struct pci_dev *pdev)
 	rvu_flr_wq_destroy(rvu);
 	rvu_cgx_wq_destroy(rvu);
 	rvu_mbox_destroy(&rvu->afpf_wq_info);
+	rvu_disable_sriov(rvu);
 	rvu_reset_all_blocks(rvu);
 	rvu_free_hw_resources(rvu);
 

drivers/net/ethernet/marvell/octeontx2/af/rvu.h

@@ -201,7 +201,8 @@ struct rvu {
 	struct rvu_hwinfo       *hw;
 	struct rvu_pfvf		*pf;
 	struct rvu_pfvf		*hwvf;
-	struct mutex            rsrc_lock; /* Serialize resource alloc/free */
+	struct mutex		rsrc_lock; /* Serialize resource alloc/free */
+	int			vfs; /* Number of VFs attached to RVU */
 
 	/* Mbox */
 	struct mbox_wq_info	afpf_wq_info;