be2net: avoid disabling sriov while VFs are assigned

Calling pci_disable_sriov() while VFs are assigned to VMs causes
kernel panic. This patch uses PCI_DEV_FLAGS_ASSIGNED bit state of the
VF's pci_dev to avoid this. Also, the unconditional function reset cmd
issued on a PF probe can delete the VF configuration for the
previously enabled VFs. A scratchpad register is now used to issue a
function reset only when needed (i.e., in a crash dump scenario.)

Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 134 insertions, 89 deletions

diff --git a/drivers/net/ethernet/emulex/benet/be.h b/drivers/net/ethernet/emulex/benet/be.h
index c3ee9103ff4f..ecf1a81f26e2 100644
--- a/drivers/net/ethernet/emulex/benet/be.h
+++ b/drivers/net/ethernet/emulex/benet/be.h
@@ -313,6 +313,11 @@ struct be_vf_cfg {
 	u32 tx_rate;
 };
 
+enum vf_state {
+	ENABLED = 0,
+	ASSIGNED = 1
+};
+
 #define BE_FLAGS_LINK_STATUS_INIT		1
 #define BE_FLAGS_WORKER_SCHEDULED		(1 << 3)
 #define BE_UC_PMAC_COUNT		30
@@ -403,8 +408,9 @@ struct be_adapter {
 	u32 flash_status;
 	struct completion flash_compl;
 
-	u32 num_vfs;
-	u8 is_virtfn;
+	u32 num_vfs;		/* Number of VFs provisioned by PF driver */
+	u32 dev_num_vfs;	/* Number of VFs supported by HW */
+	u8 virtfn;
 	struct be_vf_cfg *vf_cfg;
 	bool be3_native;
 	u32 sli_family;
@@ -417,8 +423,10 @@ struct be_adapter {
 	u32 uc_macs;		/* Count of secondary UC MAC programmed */
 };
 
-#define be_physfn(adapter) (!adapter->is_virtfn)
+#define be_physfn(adapter)		(!adapter->virtfn)
 #define	sriov_enabled(adapter)		(adapter->num_vfs > 0)
+#define	sriov_want(adapter)		(adapter->dev_num_vfs && num_vfs && \
+					 be_physfn(adapter))
 #define for_all_vfs(adapter, vf_cfg, i)					\
 	for (i = 0, vf_cfg = &adapter->vf_cfg[i]; i < adapter->num_vfs;	\
 		i++, vf_cfg++)
@@ -547,14 +555,6 @@ static inline u8 is_udp_pkt(struct sk_buff *skb)
 	return val;
 }
 
-static inline void be_check_sriov_fn_type(struct be_adapter *adapter)
-{
-	u32 sli_intf;
-
-	pci_read_config_dword(adapter->pdev, SLI_INTF_REG_OFFSET, &sli_intf);
-	adapter->is_virtfn = (sli_intf & SLI_INTF_FT_MASK) ? 1 : 0;
-}
-
 static inline void be_vf_eth_addr_generate(struct be_adapter *adapter, u8 *mac)
 {
 	u32 addr;
diff --git a/drivers/net/ethernet/emulex/benet/be_hw.h b/drivers/net/ethernet/emulex/benet/be_hw.h
index 0949aa609164..f38b58c8dbba 100644
--- a/drivers/net/ethernet/emulex/benet/be_hw.h
+++ b/drivers/net/ethernet/emulex/benet/be_hw.h
@@ -58,6 +58,8 @@
 
 #define SLI_PORT_CONTROL_IP_MASK	0x08000000
 
+#define PCICFG_CUST_SCRATCHPAD_CSR	0x1EC
+
 /********* Memory BAR register ************/
 #define PCICFG_MEMBAR_CTRL_INT_CTRL_OFFSET 	0xfc
 /* Host Interrupt Enable, if set interrupts are enabled although "PCI Interrupt
diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index 6d5d30be0481..a01f73467532 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -1049,6 +1049,29 @@ static int be_set_vf_tx_rate(struct net_device *netdev,
 	return status;
 }
 
+static int be_find_vfs(struct be_adapter *adapter, int vf_state)
+{
+	struct pci_dev *dev, *pdev = adapter->pdev;
+	int vfs = 0, assigned_vfs = 0, pos, vf_fn;
+	u16 offset, stride;
+
+	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_SRIOV);
+	pci_read_config_word(pdev, pos + PCI_SRIOV_VF_OFFSET, &offset);
+	pci_read_config_word(pdev, pos + PCI_SRIOV_VF_STRIDE, &stride);
+
+	dev = pci_get_device(pdev->vendor, PCI_ANY_ID, NULL);
+	while (dev) {
+		vf_fn = (pdev->devfn + offset + stride * vfs) & 0xFFFF;
+		if (dev->is_virtfn && dev->devfn == vf_fn) {
+			vfs++;
+			if (dev->dev_flags & PCI_DEV_FLAGS_ASSIGNED)
+				assigned_vfs++;
+		}
+		dev = pci_get_device(pdev->vendor, PCI_ANY_ID, dev);
+	}
+	return (vf_state == ASSIGNED) ? assigned_vfs : vfs;
+}
+
 static void be_eqd_update(struct be_adapter *adapter, struct be_eq_obj *eqo)
 {
 	struct be_rx_stats *stats = rx_stats(&adapter->rx_obj[eqo->idx]);
@@ -1789,9 +1812,9 @@ static void be_tx_queues_destroy(struct be_adapter *adapter)
 
 static int be_num_txqs_want(struct be_adapter *adapter)
 {
-	if (sriov_enabled(adapter) || be_is_mc(adapter) ||
-		lancer_chip(adapter) || !be_physfn(adapter) ||
-		adapter->generation == BE_GEN2)
+	if (sriov_want(adapter) || be_is_mc(adapter) ||
+	    lancer_chip(adapter) || !be_physfn(adapter) ||
+	    adapter->generation == BE_GEN2)
 		return 1;
 	else
 		return MAX_TX_QS;
@@ -2118,7 +2141,7 @@ static void be_msix_disable(struct be_adapter *adapter)
 static uint be_num_rss_want(struct be_adapter *adapter)
 {
 	if ((adapter->function_caps & BE_FUNCTION_CAPS_RSS) &&
-	     adapter->num_vfs == 0 && be_physfn(adapter) &&
+	     !sriov_want(adapter) && be_physfn(adapter) &&
 	     !be_is_mc(adapter))
 		return (adapter->be3_native) ? BE3_MAX_RSS_QS : BE2_MAX_RSS_QS;
 	else
@@ -2152,53 +2175,6 @@ done:
 	return;
 }
 
-static int be_sriov_enable(struct be_adapter *adapter)
-{
-	be_check_sriov_fn_type(adapter);
-
-#ifdef CONFIG_PCI_IOV
-	if (be_physfn(adapter) && num_vfs) {
-		int status, pos;
-		u16 dev_vfs;
-
-		pos = pci_find_ext_capability(adapter->pdev,
-						PCI_EXT_CAP_ID_SRIOV);
-		pci_read_config_word(adapter->pdev,
-				     pos + PCI_SRIOV_TOTAL_VF, &dev_vfs);
-
-		adapter->num_vfs = min_t(u16, num_vfs, dev_vfs);
-		if (adapter->num_vfs != num_vfs)
-			dev_info(&adapter->pdev->dev,
-				 "Device supports %d VFs and not %d\n",
-				 adapter->num_vfs, num_vfs);
-
-		status = pci_enable_sriov(adapter->pdev, adapter->num_vfs);
-		if (status)
-			adapter->num_vfs = 0;
-
-		if (adapter->num_vfs) {
-			adapter->vf_cfg = kcalloc(num_vfs,
-						sizeof(struct be_vf_cfg),
-						GFP_KERNEL);
-			if (!adapter->vf_cfg)
-				return -ENOMEM;
-		}
-	}
-#endif
-	return 0;
-}
-
-static void be_sriov_disable(struct be_adapter *adapter)
-{
-#ifdef CONFIG_PCI_IOV
-	if (sriov_enabled(adapter)) {
-		pci_disable_sriov(adapter->pdev);
-		kfree(adapter->vf_cfg);
-		adapter->num_vfs = 0;
-	}
-#endif
-}
-
 static inline int be_msix_vec_get(struct be_adapter *adapter,
 				struct be_eq_obj *eqo)
 {
@@ -2500,6 +2476,11 @@ static void be_vf_clear(struct be_adapter *adapter)
 	struct be_vf_cfg *vf_cfg;
 	u32 vf;
 
+	if (be_find_vfs(adapter, ASSIGNED)) {
+		dev_warn(&adapter->pdev->dev, "VFs are assigned to VMs\n");
+		goto done;
+	}
+
 	for_all_vfs(adapter, vf_cfg, vf) {
 		if (lancer_chip(adapter))
 			be_cmd_set_mac_list(adapter, NULL, 0, vf + 1);
@@ -2509,6 +2490,10 @@ static void be_vf_clear(struct be_adapter *adapter)
 
 		be_cmd_if_destroy(adapter, vf_cfg->if_handle, vf + 1);
 	}
+	pci_disable_sriov(adapter->pdev);
+done:
+	kfree(adapter->vf_cfg);
+	adapter->num_vfs = 0;
 }
 
 static int be_clear(struct be_adapter *adapter)
@@ -2538,29 +2523,60 @@ static int be_clear(struct be_adapter *adapter)
 	be_cmd_fw_clean(adapter);
 
 	be_msix_disable(adapter);
-	kfree(adapter->pmac_id);
+	pci_write_config_dword(adapter->pdev, PCICFG_CUST_SCRATCHPAD_CSR, 0);
 	return 0;
 }
 
-static void be_vf_setup_init(struct be_adapter *adapter)
+static int be_vf_setup_init(struct be_adapter *adapter)
 {
 	struct be_vf_cfg *vf_cfg;
 	int vf;
 
+	adapter->vf_cfg = kcalloc(adapter->num_vfs, sizeof(*vf_cfg),
+				  GFP_KERNEL);
+	if (!adapter->vf_cfg)
+		return -ENOMEM;
+
 	for_all_vfs(adapter, vf_cfg, vf) {
 		vf_cfg->if_handle = -1;
 		vf_cfg->pmac_id = -1;
 	}
+	return 0;
 }
 
 static int be_vf_setup(struct be_adapter *adapter)
 {
 	struct be_vf_cfg *vf_cfg;
+	struct device *dev = &adapter->pdev->dev;
 	u32 cap_flags, en_flags, vf;
 	u16 def_vlan, lnk_speed;
-	int status;
+	int status, enabled_vfs;
+
+	enabled_vfs = be_find_vfs(adapter, ENABLED);
+	if (enabled_vfs) {
+		dev_warn(dev, "%d VFs are already enabled\n", enabled_vfs);
+		dev_warn(dev, "Ignoring num_vfs=%d setting\n", num_vfs);
+		return 0;
+	}
 
-	be_vf_setup_init(adapter);
+	if (num_vfs > adapter->dev_num_vfs) {
+		dev_warn(dev, "Device supports %d VFs and not %d\n",
+			 adapter->dev_num_vfs, num_vfs);
+		num_vfs = adapter->dev_num_vfs;
+	}
+
+	status = pci_enable_sriov(adapter->pdev, num_vfs);
+	if (!status) {
+		adapter->num_vfs = num_vfs;
+	} else {
+		/* Platform doesn't support SRIOV though device supports it */
+		dev_warn(dev, "SRIOV enable failed\n");
+		return 0;
+	}
+
+	status = be_vf_setup_init(adapter);
+	if (status)
+		goto err;
 
 	cap_flags = en_flags = BE_IF_FLAGS_UNTAGGED | BE_IF_FLAGS_BROADCAST |
 				BE_IF_FLAGS_MULTICAST;
@@ -2571,9 +2587,11 @@ static int be_vf_setup(struct be_adapter *adapter)
 			goto err;
 	}
 
-	status = be_vf_eth_addr_config(adapter);
-	if (status)
-		goto err;
+	if (!enabled_vfs) {
+		status = be_vf_eth_addr_config(adapter);
+		if (status)
+			goto err;
+	}
 
 	for_all_vfs(adapter, vf_cfg, vf) {
 		status = be_cmd_link_status_query(adapter, NULL, &lnk_speed,
@@ -2630,9 +2648,25 @@ do_none:
 	return status;
 }
 
+/* Routine to query per function resource limits */
+static int be_get_config(struct be_adapter *adapter)
+{
+	int pos;
+	u16 dev_num_vfs;
+
+	pos = pci_find_ext_capability(adapter->pdev, PCI_EXT_CAP_ID_SRIOV);
+	if (pos) {
+		pci_read_config_word(adapter->pdev, pos + PCI_SRIOV_TOTAL_VF,
+				     &dev_num_vfs);
+		adapter->dev_num_vfs = dev_num_vfs;
+	}
+	return 0;
+}
+
 static int be_setup(struct be_adapter *adapter)
 {
 	struct net_device *netdev = adapter->netdev;
+	struct device *dev = &adapter->pdev->dev;
 	u32 cap_flags, en_flags;
 	u32 tx_fc, rx_fc;
 	int status;
@@ -2640,6 +2674,8 @@ static int be_setup(struct be_adapter *adapter)
 
 	be_setup_init(adapter);
 
+	be_get_config(adapter);
+
 	be_cmd_req_native_mode(adapter);
 
 	be_msix_enable(adapter);
@@ -2718,10 +2754,11 @@ static int be_setup(struct be_adapter *adapter)
 
 	pcie_set_readrq(adapter->pdev, 4096);
 
-	if (sriov_enabled(adapter)) {
-		status = be_vf_setup(adapter);
-		if (status)
-			goto err;
+	if (be_physfn(adapter) && num_vfs) {
+		if (adapter->dev_num_vfs)
+			be_vf_setup(adapter);
+		else
+			dev_warn(dev, "device doesn't support SRIOV\n");
 	}
 
 	be_cmd_get_phy_info(adapter);
@@ -2731,6 +2768,7 @@ static int be_setup(struct be_adapter *adapter)
 	schedule_delayed_work(&adapter->work, msecs_to_jiffies(1000));
 	adapter->flags |= BE_FLAGS_WORKER_SCHEDULED;
 
+	pci_write_config_dword(adapter->pdev, PCICFG_CUST_SCRATCHPAD_CSR, 1);
 	return 0;
 err:
 	be_clear(adapter);
@@ -3352,8 +3390,6 @@ static void __devexit be_remove(struct pci_dev *pdev)
 
 	be_ctrl_cleanup(adapter);
 
-	be_sriov_disable(adapter);
-
 	pci_set_drvdata(pdev, NULL);
 	pci_release_regions(pdev);
 	pci_disable_device(pdev);
@@ -3367,7 +3403,7 @@ bool be_is_wol_supported(struct be_adapter *adapter)
 		!be_is_wol_excluded(adapter)) ? true : false;
 }
 
-static int be_get_config(struct be_adapter *adapter)
+static int be_get_initial_config(struct be_adapter *adapter)
 {
 	int status;
 
@@ -3410,7 +3446,7 @@ static int be_get_config(struct be_adapter *adapter)
 	return 0;
 }
 
-static int be_dev_family_check(struct be_adapter *adapter)
+static int be_dev_type_check(struct be_adapter *adapter)
 {
 	struct pci_dev *pdev = adapter->pdev;
 	u32 sli_intf = 0, if_type;
@@ -3443,6 +3479,9 @@ static int be_dev_family_check(struct be_adapter *adapter)
 	default:
 		adapter->generation = 0;
 	}
+
+	pci_read_config_dword(adapter->pdev, SLI_INTF_REG_OFFSET, &sli_intf);
+	adapter->virtfn = (sli_intf & SLI_INTF_FT_MASK) ? 1 : 0;
 	return 0;
 }
 
@@ -3586,6 +3625,14 @@ reschedule:
 	schedule_delayed_work(&adapter->work, msecs_to_jiffies(1000));
 }
 
+static bool be_reset_required(struct be_adapter *adapter)
+{
+	u32 reg;
+
+	pci_read_config_dword(adapter->pdev, PCICFG_CUST_SCRATCHPAD_CSR, &reg);
+	return reg;
+}
+
 static int __devinit be_probe(struct pci_dev *pdev,
 			const struct pci_device_id *pdev_id)
 {
@@ -3611,7 +3658,7 @@ static int __devinit be_probe(struct pci_dev *pdev,
 	adapter->pdev = pdev;
 	pci_set_drvdata(pdev, adapter);
 
-	status = be_dev_family_check(adapter);
+	status = be_dev_type_check(adapter);
 	if (status)
 		goto free_netdev;
 
@@ -3629,13 +3676,9 @@ static int __devinit be_probe(struct pci_dev *pdev,
 		}
 	}
 
-	status = be_sriov_enable(adapter);
-	if (status)
-		goto free_netdev;
-
 	status = be_ctrl_init(adapter);
 	if (status)
-		goto disable_sriov;
+		goto free_netdev;
 
 	if (lancer_chip(adapter)) {
 		status = lancer_wait_ready(adapter);
@@ -3662,9 +3705,11 @@ static int __devinit be_probe(struct pci_dev *pdev,
 	if (status)
 		goto ctrl_clean;
 
-	status = be_cmd_reset_function(adapter);
-	if (status)
-		goto ctrl_clean;
+	if (be_reset_required(adapter)) {
+		status = be_cmd_reset_function(adapter);
+		if (status)
+			goto ctrl_clean;
+	}
 
 	/* The INTR bit may be set in the card when probed by a kdump kernel
 	 * after a crash.
@@ -3676,7 +3721,7 @@ static int __devinit be_probe(struct pci_dev *pdev,
 	if (status)
 		goto ctrl_clean;
 
-	status = be_get_config(adapter);
+	status = be_get_initial_config(adapter);
 	if (status)
 		goto stats_clean;
 
@@ -3705,8 +3750,6 @@ stats_clean:
 	be_stats_cleanup(adapter);
 ctrl_clean:
 	be_ctrl_cleanup(adapter);
-disable_sriov:
-	be_sriov_disable(adapter);
 free_netdev:
 	free_netdev(netdev);
 	pci_set_drvdata(pdev, NULL);