1 files changed, 308 insertions, 61 deletions

diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index b619a3ec245b..24046fe16634 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -39,8 +39,6 @@
 #include "ibmveth.h"
 
 static irqreturn_t ibmveth_interrupt(int irq, void *dev_instance);
-static void ibmveth_rxq_harvest_buffer(struct ibmveth_adapter *adapter,
-				       bool reuse);
 static unsigned long ibmveth_get_desired_dma(struct vio_dev *vdev);
 
 static struct kobj_type ktype_veth_pool;
@@ -231,7 +229,10 @@ static void ibmveth_replenish_buffer_pool(struct ibmveth_adapter *adapter,
 		index = pool->free_map[free_index];
 		skb = NULL;
 
-		BUG_ON(index == IBM_VETH_INVALID_MAP);
+		if (WARN_ON(index == IBM_VETH_INVALID_MAP)) {
+			schedule_work(&adapter->work);
+			goto bad_index_failure;
+		}
 
 		/* are we allocating a new buffer or recycling an old one */
 		if (pool->skbuff[index])
@@ -300,6 +301,7 @@ failure:
 		                 DMA_FROM_DEVICE);
 	dev_kfree_skb_any(pool->skbuff[index]);
 	pool->skbuff[index] = NULL;
+bad_index_failure:
 	adapter->replenish_add_buff_failure++;
 
 	mb();
@@ -370,20 +372,36 @@ static void ibmveth_free_buffer_pool(struct ibmveth_adapter *adapter,
 	}
 }
 
-/* remove a buffer from a pool */
-static void ibmveth_remove_buffer_from_pool(struct ibmveth_adapter *adapter,
-					    u64 correlator, bool reuse)
+/**
+ * ibmveth_remove_buffer_from_pool - remove a buffer from a pool
+ * @adapter: adapter instance
+ * @correlator: identifies pool and index
+ * @reuse: whether to reuse buffer
+ *
+ * Return:
+ * * %0       - success
+ * * %-EINVAL - correlator maps to pool or index out of range
+ * * %-EFAULT - pool and index map to null skb
+ */
+static int ibmveth_remove_buffer_from_pool(struct ibmveth_adapter *adapter,
+					   u64 correlator, bool reuse)
 {
 	unsigned int pool  = correlator >> 32;
 	unsigned int index = correlator & 0xffffffffUL;
 	unsigned int free_index;
 	struct sk_buff *skb;
 
-	BUG_ON(pool >= IBMVETH_NUM_BUFF_POOLS);
-	BUG_ON(index >= adapter->rx_buff_pool[pool].size);
+	if (WARN_ON(pool >= IBMVETH_NUM_BUFF_POOLS) ||
+	    WARN_ON(index >= adapter->rx_buff_pool[pool].size)) {
+		schedule_work(&adapter->work);
+		return -EINVAL;
+	}
 
 	skb = adapter->rx_buff_pool[pool].skbuff[index];
-	BUG_ON(skb == NULL);
+	if (WARN_ON(!skb)) {
+		schedule_work(&adapter->work);
+		return -EFAULT;
+	}
 
 	/* if we are going to reuse the buffer then keep the pointers around
 	 * but mark index as available. replenish will see the skb pointer and
@@ -411,6 +429,8 @@ static void ibmveth_remove_buffer_from_pool(struct ibmveth_adapter *adapter,
 	mb();
 
 	atomic_dec(&(adapter->rx_buff_pool[pool].available));
+
+	return 0;
 }
 
 /* get the current buffer on the rx queue */
@@ -420,24 +440,44 @@ static inline struct sk_buff *ibmveth_rxq_get_buffer(struct ibmveth_adapter *ada
 	unsigned int pool = correlator >> 32;
 	unsigned int index = correlator & 0xffffffffUL;
 
-	BUG_ON(pool >= IBMVETH_NUM_BUFF_POOLS);
-	BUG_ON(index >= adapter->rx_buff_pool[pool].size);
+	if (WARN_ON(pool >= IBMVETH_NUM_BUFF_POOLS) ||
+	    WARN_ON(index >= adapter->rx_buff_pool[pool].size)) {
+		schedule_work(&adapter->work);
+		return NULL;
+	}
 
 	return adapter->rx_buff_pool[pool].skbuff[index];
 }
 
-static void ibmveth_rxq_harvest_buffer(struct ibmveth_adapter *adapter,
-				       bool reuse)
+/**
+ * ibmveth_rxq_harvest_buffer - Harvest buffer from pool
+ *
+ * @adapter: pointer to adapter
+ * @reuse:   whether to reuse buffer
+ *
+ * Context: called from ibmveth_poll
+ *
+ * Return:
+ * * %0    - success
+ * * other - non-zero return from ibmveth_remove_buffer_from_pool
+ */
+static int ibmveth_rxq_harvest_buffer(struct ibmveth_adapter *adapter,
+				      bool reuse)
 {
 	u64 cor;
+	int rc;
 
 	cor = adapter->rx_queue.queue_addr[adapter->rx_queue.index].correlator;
-	ibmveth_remove_buffer_from_pool(adapter, cor, reuse);
+	rc = ibmveth_remove_buffer_from_pool(adapter, cor, reuse);
+	if (unlikely(rc))
+		return rc;
 
 	if (++adapter->rx_queue.index == adapter->rx_queue.num_slots) {
 		adapter->rx_queue.index = 0;
 		adapter->rx_queue.toggle = !adapter->rx_queue.toggle;
 	}
+
+	return 0;
 }
 
 static void ibmveth_free_tx_ltb(struct ibmveth_adapter *adapter, int idx)
@@ -709,6 +749,35 @@ static int ibmveth_close(struct net_device *netdev)
 	return 0;
 }
 
+/**
+ * ibmveth_reset - Handle scheduled reset work
+ *
+ * @w: pointer to work_struct embedded in adapter structure
+ *
+ * Context: This routine acquires rtnl_mutex and disables its NAPI through
+ *          ibmveth_close. It can't be called directly in a context that has
+ *          already acquired rtnl_mutex or disabled its NAPI, or directly from
+ *          a poll routine.
+ *
+ * Return: void
+ */
+static void ibmveth_reset(struct work_struct *w)
+{
+	struct ibmveth_adapter *adapter = container_of(w, struct ibmveth_adapter, work);
+	struct net_device *netdev = adapter->netdev;
+
+	netdev_dbg(netdev, "reset starting\n");
+
+	rtnl_lock();
+
+	dev_close(adapter->netdev);
+	dev_open(adapter->netdev, NULL);
+
+	rtnl_unlock();
+
+	netdev_dbg(netdev, "reset complete\n");
+}
+
 static int ibmveth_set_link_ksettings(struct net_device *dev,
 				      const struct ethtool_link_ksettings *cmd)
 {
@@ -1324,7 +1393,8 @@ restart_poll:
 			wmb(); /* suggested by larson1 */
 			adapter->rx_invalid_buffer++;
 			netdev_dbg(netdev, "recycling invalid buffer\n");
-			ibmveth_rxq_harvest_buffer(adapter, true);
+			if (unlikely(ibmveth_rxq_harvest_buffer(adapter, true)))
+				break;
 		} else {
 			struct sk_buff *skb, *new_skb;
 			int length = ibmveth_rxq_frame_length(adapter);
@@ -1334,6 +1404,8 @@ restart_poll:
 			__sum16 iph_check = 0;
 
 			skb = ibmveth_rxq_get_buffer(adapter);
+			if (unlikely(!skb))
+				break;
 
 			/* if the large packet bit is set in the rx queue
 			 * descriptor, the mss will be written by PHYP eight
@@ -1357,10 +1429,12 @@ restart_poll:
 				if (rx_flush)
 					ibmveth_flush_buffer(skb->data,
 						length + offset);
-				ibmveth_rxq_harvest_buffer(adapter, true);
+				if (unlikely(ibmveth_rxq_harvest_buffer(adapter, true)))
+					break;
 				skb = new_skb;
 			} else {
-				ibmveth_rxq_harvest_buffer(adapter, false);
+				if (unlikely(ibmveth_rxq_harvest_buffer(adapter, false)))
+					break;
 				skb_reserve(skb, offset);
 			}
 
@@ -1407,7 +1481,10 @@ restart_poll:
 	 * then check once more to make sure we are done.
 	 */
 	lpar_rc = h_vio_signal(adapter->vdev->unit_address, VIO_IRQ_ENABLE);
-	BUG_ON(lpar_rc != H_SUCCESS);
+	if (WARN_ON(lpar_rc != H_SUCCESS)) {
+		schedule_work(&adapter->work);
+		goto out;
+	}
 
 	if (ibmveth_rxq_pending_buffer(adapter) && napi_schedule(napi)) {
 		lpar_rc = h_vio_signal(adapter->vdev->unit_address,
@@ -1428,7 +1505,7 @@ static irqreturn_t ibmveth_interrupt(int irq, void *dev_instance)
 	if (napi_schedule_prep(&adapter->napi)) {
 		lpar_rc = h_vio_signal(adapter->vdev->unit_address,
 				       VIO_IRQ_DISABLE);
-		BUG_ON(lpar_rc != H_SUCCESS);
+		WARN_ON(lpar_rc != H_SUCCESS);
 		__napi_schedule(&adapter->napi);
 	}
 	return IRQ_HANDLED;
@@ -1670,6 +1747,7 @@ static int ibmveth_probe(struct vio_dev *dev, const struct vio_device_id *id)
 
 	adapter->vdev = dev;
 	adapter->netdev = netdev;
+	INIT_WORK(&adapter->work, ibmveth_reset);
 	adapter->mcastFilterSize = be32_to_cpu(*mcastFilterSize_p);
 	ibmveth_init_link_settings(netdev);
 
@@ -1762,6 +1840,8 @@ static void ibmveth_remove(struct vio_dev *dev)
 	struct ibmveth_adapter *adapter = netdev_priv(netdev);
 	int i;
 
+	cancel_work_sync(&adapter->work);
+
 	for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++)
 		kobject_put(&adapter->rx_buff_pool[i].kobj);
 
@@ -1791,6 +1871,26 @@ static ssize_t veth_pool_show(struct kobject *kobj,
 	return 0;
 }
 
+/**
+ * veth_pool_store - sysfs store handler for pool attributes
+ * @kobj: kobject embedded in pool
+ * @attr: attribute being changed
+ * @buf: value being stored
+ * @count: length of @buf in bytes
+ *
+ * Stores new value in pool attribute. Verifies the range of the new value for
+ * size and buff_size. Verifies that at least one pool remains available to
+ * receive MTU-sized packets.
+ *
+ * Context: Process context.
+ *          Takes and releases rtnl_mutex to ensure correct ordering of close
+ *	    and open calls.
+ * Return:
+ * * %-EPERM  - Not allowed to disabled all MTU-sized buffer pools
+ * * %-EINVAL - New pool size or buffer size is out of range
+ * * count    - Return count for success
+ * * other    - Return value from a failed ibmveth_open call
+ */
 static ssize_t veth_pool_store(struct kobject *kobj, struct attribute *attr,
 			       const char *buf, size_t count)
 {
@@ -1800,24 +1900,30 @@ static ssize_t veth_pool_store(struct kobject *kobj, struct attribute *attr,
 	struct net_device *netdev = dev_get_drvdata(kobj_to_dev(kobj->parent));
 	struct ibmveth_adapter *adapter = netdev_priv(netdev);
 	long value = simple_strtol(buf, NULL, 10);
+	bool change = false;
+	u32 newbuff_size;
+	u32 oldbuff_size;
+	int newactive;
+	int oldactive;
+	u32 newsize;
+	u32 oldsize;
 	long rc;
 
+	rtnl_lock();
+
+	oldbuff_size = pool->buff_size;
+	oldactive = pool->active;
+	oldsize = pool->size;
+
+	newbuff_size = oldbuff_size;
+	newactive = oldactive;
+	newsize = oldsize;
+
 	if (attr == &veth_active_attr) {
-		if (value && !pool->active) {
-			if (netif_running(netdev)) {
-				if (ibmveth_alloc_buffer_pool(pool)) {
-					netdev_err(netdev,
-						   "unable to alloc pool\n");
-					return -ENOMEM;
-				}
-				pool->active = 1;
-				ibmveth_close(netdev);
-				if ((rc = ibmveth_open(netdev)))
-					return rc;
-			} else {
-				pool->active = 1;
-			}
-		} else if (!value && pool->active) {
+		if (value && !oldactive) {
+			newactive = 1;
+			change = true;
+		} else if (!value && oldactive) {
 			int mtu = netdev->mtu + IBMVETH_BUFF_OH;
 			int i;
 			/* Make sure there is a buffer pool with buffers that
@@ -1833,48 +1939,60 @@ static ssize_t veth_pool_store(struct kobject *kobj, struct attribute *attr,
 
 			if (i == IBMVETH_NUM_BUFF_POOLS) {
 				netdev_err(netdev, "no active pool >= MTU\n");
-				return -EPERM;
+				rc = -EPERM;
+				goto unlock_err;
 			}
 
-			if (netif_running(netdev)) {
-				ibmveth_close(netdev);
-				pool->active = 0;
-				if ((rc = ibmveth_open(netdev)))
-					return rc;
-			}
-			pool->active = 0;
+			newactive = 0;
+			change = true;
 		}
 	} else if (attr == &veth_num_attr) {
 		if (value <= 0 || value > IBMVETH_MAX_POOL_COUNT) {
-			return -EINVAL;
-		} else {
-			if (netif_running(netdev)) {
-				ibmveth_close(netdev);
-				pool->size = value;
-				if ((rc = ibmveth_open(netdev)))
-					return rc;
-			} else {
-				pool->size = value;
-			}
+			rc = -EINVAL;
+			goto unlock_err;
+		}
+		if (value != oldsize) {
+			newsize = value;
+			change = true;
 		}
 	} else if (attr == &veth_size_attr) {
 		if (value <= IBMVETH_BUFF_OH || value > IBMVETH_MAX_BUF_SIZE) {
-			return -EINVAL;
-		} else {
-			if (netif_running(netdev)) {
-				ibmveth_close(netdev);
-				pool->buff_size = value;
-				if ((rc = ibmveth_open(netdev)))
-					return rc;
-			} else {
-				pool->buff_size = value;
+			rc = -EINVAL;
+			goto unlock_err;
+		}
+		if (value != oldbuff_size) {
+			newbuff_size = value;
+			change = true;
+		}
+	}
+
+	if (change) {
+		if (netif_running(netdev))
+			ibmveth_close(netdev);
+
+		pool->active = newactive;
+		pool->buff_size = newbuff_size;
+		pool->size = newsize;
+
+		if (netif_running(netdev)) {
+			rc = ibmveth_open(netdev);
+			if (rc) {
+				pool->active = oldactive;
+				pool->buff_size = oldbuff_size;
+				pool->size = oldsize;
+				goto unlock_err;
 			}
 		}
 	}
+	rtnl_unlock();
 
 	/* kick the interrupt handler to allocate/deallocate pools */
 	ibmveth_interrupt(netdev->irq, netdev);
 	return count;
+
+unlock_err:
+	rtnl_unlock();
+	return rc;
 }
 
 
@@ -1947,3 +2065,132 @@ static void __exit ibmveth_module_exit(void)
 
 module_init(ibmveth_module_init);
 module_exit(ibmveth_module_exit);
+
+#ifdef CONFIG_IBMVETH_KUNIT_TEST
+#include <kunit/test.h>
+
+/**
+ * ibmveth_reset_kunit - reset routine for running in KUnit environment
+ *
+ * @w: pointer to work_struct embedded in adapter structure
+ *
+ * Context: Called in the KUnit environment. Does nothing.
+ *
+ * Return: void
+ */
+static void ibmveth_reset_kunit(struct work_struct *w)
+{
+	netdev_dbg(NULL, "reset_kunit starting\n");
+	netdev_dbg(NULL, "reset_kunit complete\n");
+}
+
+/**
+ * ibmveth_remove_buffer_from_pool_test - unit test for some of
+ *                                        ibmveth_remove_buffer_from_pool
+ * @test: pointer to kunit structure
+ *
+ * Tests the error returns from ibmveth_remove_buffer_from_pool.
+ * ibmveth_remove_buffer_from_pool also calls WARN_ON, so dmesg should be
+ * checked to see that these warnings happened.
+ *
+ * Return: void
+ */
+static void ibmveth_remove_buffer_from_pool_test(struct kunit *test)
+{
+	struct ibmveth_adapter *adapter = kunit_kzalloc(test, sizeof(*adapter), GFP_KERNEL);
+	struct ibmveth_buff_pool *pool;
+	u64 correlator;
+
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, adapter);
+
+	INIT_WORK(&adapter->work, ibmveth_reset_kunit);
+
+	/* Set sane values for buffer pools */
+	for (int i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++)
+		ibmveth_init_buffer_pool(&adapter->rx_buff_pool[i], i,
+					 pool_count[i], pool_size[i],
+					 pool_active[i]);
+
+	pool = &adapter->rx_buff_pool[0];
+	pool->skbuff = kunit_kcalloc(test, pool->size, sizeof(void *), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pool->skbuff);
+
+	correlator = ((u64)IBMVETH_NUM_BUFF_POOLS << 32) | 0;
+	KUNIT_EXPECT_EQ(test, -EINVAL, ibmveth_remove_buffer_from_pool(adapter, correlator, false));
+	KUNIT_EXPECT_EQ(test, -EINVAL, ibmveth_remove_buffer_from_pool(adapter, correlator, true));
+
+	correlator = ((u64)0 << 32) | adapter->rx_buff_pool[0].size;
+	KUNIT_EXPECT_EQ(test, -EINVAL, ibmveth_remove_buffer_from_pool(adapter, correlator, false));
+	KUNIT_EXPECT_EQ(test, -EINVAL, ibmveth_remove_buffer_from_pool(adapter, correlator, true));
+
+	correlator = (u64)0 | 0;
+	pool->skbuff[0] = NULL;
+	KUNIT_EXPECT_EQ(test, -EFAULT, ibmveth_remove_buffer_from_pool(adapter, correlator, false));
+	KUNIT_EXPECT_EQ(test, -EFAULT, ibmveth_remove_buffer_from_pool(adapter, correlator, true));
+
+	flush_work(&adapter->work);
+}
+
+/**
+ * ibmveth_rxq_get_buffer_test - unit test for ibmveth_rxq_get_buffer
+ * @test: pointer to kunit structure
+ *
+ * Tests ibmveth_rxq_get_buffer. ibmveth_rxq_get_buffer also calls WARN_ON for
+ * the NULL returns, so dmesg should be checked to see that these warnings
+ * happened.
+ *
+ * Return: void
+ */
+static void ibmveth_rxq_get_buffer_test(struct kunit *test)
+{
+	struct ibmveth_adapter *adapter = kunit_kzalloc(test, sizeof(*adapter), GFP_KERNEL);
+	struct sk_buff *skb = kunit_kzalloc(test, sizeof(*skb), GFP_KERNEL);
+	struct ibmveth_buff_pool *pool;
+
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, adapter);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, skb);
+
+	INIT_WORK(&adapter->work, ibmveth_reset_kunit);
+
+	adapter->rx_queue.queue_len = 1;
+	adapter->rx_queue.index = 0;
+	adapter->rx_queue.queue_addr = kunit_kzalloc(test, sizeof(struct ibmveth_rx_q_entry),
+						     GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, adapter->rx_queue.queue_addr);
+
+	/* Set sane values for buffer pools */
+	for (int i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++)
+		ibmveth_init_buffer_pool(&adapter->rx_buff_pool[i], i,
+					 pool_count[i], pool_size[i],
+					 pool_active[i]);
+
+	pool = &adapter->rx_buff_pool[0];
+	pool->skbuff = kunit_kcalloc(test, pool->size, sizeof(void *), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pool->skbuff);
+
+	adapter->rx_queue.queue_addr[0].correlator = (u64)IBMVETH_NUM_BUFF_POOLS << 32 | 0;
+	KUNIT_EXPECT_PTR_EQ(test, NULL, ibmveth_rxq_get_buffer(adapter));
+
+	adapter->rx_queue.queue_addr[0].correlator = (u64)0 << 32 | adapter->rx_buff_pool[0].size;
+	KUNIT_EXPECT_PTR_EQ(test, NULL, ibmveth_rxq_get_buffer(adapter));
+
+	pool->skbuff[0] = skb;
+	adapter->rx_queue.queue_addr[0].correlator = (u64)0 << 32 | 0;
+	KUNIT_EXPECT_PTR_EQ(test, skb, ibmveth_rxq_get_buffer(adapter));
+
+	flush_work(&adapter->work);
+}
+
+static struct kunit_case ibmveth_test_cases[] = {
+	KUNIT_CASE(ibmveth_remove_buffer_from_pool_test),
+	KUNIT_CASE(ibmveth_rxq_get_buffer_test),
+	{}
+};
+
+static struct kunit_suite ibmveth_test_suite = {
+	.name = "ibmveth-kunit-test",
+	.test_cases = ibmveth_test_cases,
+};
+
+kunit_test_suite(ibmveth_test_suite);
+#endif