fm10k: correctly clean up when init_queueing_scheme fails

Fix a kernel panic that occurs during surprise removal. Clear the
interface queue counts upon fm10k_init_msix_capability failure. This
prevents further code (fm10k_update_stats etc.) from attempting to
access unallocated queue vector or ring memory.

[  628.692648] BUG: unable to handle kernel NULL pointer dereference at 0000000000000068
[  628.692805] IP: [<ffffffffa0475caf>] fm10k_update_stats+0x7f/0x2c0 [fm10k]
[  628.693173] PGD 0
[  628.693759] Oops: 0000 [#1] SMP
[  628.699321] CPU: 10 PID: 8164 Comm: kworker/10:0 Tainted: G           OE  ------------   3.10.0-327.el7.x86_64 #1
[  628.700096] Hardware name: Supermicro X9DAi/X9DAi, BIOS 3.2 05/09/2015
[  628.700894] Workqueue: pciehp-1 pciehp_power_thread
[  628.701686] task: ffff88086559c500 ti: ffff8808593c0000 task.ti: ffff8808593c0000
[  628.702493] RIP: 0010:[<ffffffffa0475caf>]  [<ffffffffa0475caf>] fm10k_update_stats+0x7f/0x2c0 [fm10k]
[  628.703310] RSP: 0018:ffff8808593c3b00  EFLAGS: 00010282
[  628.704132] RAX: 0000000000000000 RBX: ffff880860760000 RCX: 0000000000000000
[  628.704963] RDX: ffff880860760b08 RSI: 0000000000000000 RDI: 0000000000000000
[  628.705794] RBP: ffff8808593c3b40 R08: 0000000000000000 R09: 0000000000000000
[  628.706604] R10: 0000000000000000 R11: ffff880860760c40 R12: 0000000000000080
[  628.707420] R13: ffff8808607608c0 R14: ffff880860779ec0 R15: ffff880860779f40
[  628.708238] FS:  0000000000000000(0000) GS:ffff88086f000000(0000) knlGS:0000000000000000
[  628.709071] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  628.709923] CR2: 0000000000000068 CR3: 000000000194a000 CR4: 00000000001407e0
[  628.710752] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  628.711596] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  628.712438] Stack:
[  628.713255]  ffff880860764458 ffff8808607608c0 ffff880860760000 ffff880860760000
[  628.714088]  0000000000000080 ffff8808607608c0 ffff880860779ec0 ffff880860779f40
[  628.714925]  ffff8808593c3b88 ffffffffa04780c5 ffff880860764458 0000000a8163cb5b
[  628.715752] Call Trace:
[  628.716560]  [<ffffffffa04780c5>] fm10k_down+0x155/0x1f0 [fm10k]
[  628.717367]  [<ffffffffa0479958>] fm10k_close+0x28/0xd0 [fm10k]
[  628.718184]  [<ffffffff81526365>] __dev_close_many+0x85/0xd0
[  628.718986]  [<ffffffff815264d8>] dev_close_many+0x98/0x120
[  628.719764]  [<ffffffff81527ab8>] rollback_registered_many+0xa8/0x230
[  628.720527]  [<ffffffff81527c80>] rollback_registered+0x40/0x70
[  628.721294]  [<ffffffff81529198>] unregister_netdevice_queue+0x48/0x80
[  628.722052]  [<ffffffff815291ec>] unregister_netdev+0x1c/0x30
[  628.722816]  [<ffffffffa04762b8>] fm10k_remove+0xd8/0xe0 [fm10k]
[  628.723581]  [<ffffffff81328c7b>] pci_device_remove+0x3b/0xb0
[  628.724340]  [<ffffffff813f5fbf>] __device_release_driver+0x7f/0xf0
[  628.725088]  [<ffffffff813f6053>] device_release_driver+0x23/0x30
[  628.725814]  [<ffffffff81321fe4>] pci_stop_bus_device+0x94/0xa0
[  628.726535]  [<ffffffff813220d2>] pci_stop_and_remove_bus_device+0x12/0x20
[  628.727249]  [<ffffffff8133de40>] pciehp_unconfigure_device+0xb0/0x1b0
[  628.727964]  [<ffffffff8133d822>] pciehp_disable_slot+0x52/0xd0
[  628.728664]  [<ffffffff8133d98a>] pciehp_power_thread+0xea/0x150
[  628.729358]  [<ffffffff8109d5fb>] process_one_work+0x17b/0x470
[  628.730036]  [<ffffffff8109e3cb>] worker_thread+0x11b/0x400
[  628.730730]  [<ffffffff8109e2b0>] ? rescuer_thread+0x400/0x400
[  628.731385]  [<ffffffff810a5aef>] kthread+0xcf/0xe0
[  628.732036]  [<ffffffff810a5a20>] ? kthread_create_on_node+0x140/0x140
[  628.732674]  [<ffffffff81645858>] ret_from_fork+0x58/0x90
[  628.733289]  [<ffffffff810a5a20>] ? kthread_create_on_node+0x140/0x140
[  628.733883] Code: 83 e8 01 48 8d 97 40 02 00 00 45 31 c0 4c 8d 9c c7 48 02 0
[  628.735202] RIP  [<ffffffffa0475caf>] fm10k_update_stats+0x7f/0x2c0 [fm10k]
[  628.735732]  RSP <ffff8808593c3b00>
[  628.736285] CR2: 0000000000000068
[  628.736846] ---[ end trace 9156088b311aff42 ]---

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Krishneil Singh <Krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/fm10k/fm10k_main.c

@@ -1580,6 +1580,20 @@ static void fm10k_set_num_queues(struct fm10k_intfc *interface)
 	fm10k_set_rss_queues(interface);
 }
 
+/**
+ * fm10k_reset_num_queues - Reset the number of queues to zero
+ * @interface: board private structure
+ *
+ * This function should be called whenever we need to reset the number of
+ * queues after an error condition.
+ */
+static void fm10k_reset_num_queues(struct fm10k_intfc *interface)
+{
+	interface->num_tx_queues = 0;
+	interface->num_rx_queues = 0;
+	interface->num_q_vectors = 0;
+}
+
 /**
  * fm10k_alloc_q_vector - Allocate memory for a single interrupt vector
  * @interface: board private structure to initialize
@@ -1763,9 +1777,7 @@ static int fm10k_alloc_q_vectors(struct fm10k_intfc *interface)
 	return 0;
 
 err_out:
-	interface->num_tx_queues = 0;
-	interface->num_rx_queues = 0;
-	interface->num_q_vectors = 0;
+	fm10k_reset_num_queues(interface);
 
 	while (v_idx--)
 		fm10k_free_q_vector(interface, v_idx);
@@ -1785,9 +1797,7 @@ static void fm10k_free_q_vectors(struct fm10k_intfc *interface)
 {
 	int v_idx = interface->num_q_vectors;
 
-	interface->num_tx_queues = 0;
-	interface->num_rx_queues = 0;
-	interface->num_q_vectors = 0;
+	fm10k_reset_num_queues(interface);
 
 	while (v_idx--)
 		fm10k_free_q_vector(interface, v_idx);
@@ -1995,14 +2005,15 @@ int fm10k_init_queueing_scheme(struct fm10k_intfc *interface)
 	if (err) {
 		dev_err(&interface->pdev->dev,
 			"Unable to initialize MSI-X capability\n");
-		return err;
+		goto err_init_msix;
 	}
 
 	/* Allocate memory for queues */
 	err = fm10k_alloc_q_vectors(interface);
 	if (err) {
-		fm10k_reset_msix_capability(interface);
-		return err;
+		dev_err(&interface->pdev->dev,
+			"Unable to allocate queue vectors\n");
+		goto err_alloc_q_vectors;
 	}
 
 	/* Map rings to devices, and map devices to physical queues */
@@ -2012,6 +2023,12 @@ int fm10k_init_queueing_scheme(struct fm10k_intfc *interface)
 	fm10k_init_reta(interface);
 
 	return 0;
+
+err_alloc_q_vectors:
+	fm10k_reset_msix_capability(interface);
+err_init_msix:
+	fm10k_reset_num_queues(interface);
+	return err;
 }
 
 /**