[PATCH v3] eal: add bus cleanup to eal cleanup

[Kevin Laatz <kevin.laatz@intel.com>]

During EAL init, all buses are probed and the devices found are
initialized. On eal_cleanup(), the inverse does not happen, meaning any
allocated memory and other configuration will not be cleaned up
appropriately on exit.

Currently, in order for device cleanup to take place, applications must
call the driver-relevant functions to ensure proper cleanup is done before
the application exits. Since initialization occurs for all devices on the
bus, not just the devices used by an application, it requires a)
application awareness of all bus devices that could have been probed on the
system, and b) code duplication across applications to ensure cleanup is
performed. An example of this is rte_eth_dev_close() which is commonly used
across the example applications.

This patch proposes adding bus cleanup to the eal_cleanup() to make EAL's
init/exit more symmetrical, ensuring all bus devices are cleaned up
appropriately without the application needing to be aware of all bus types
that may have been probed during initialization.

Contained in this patch are the changes required to perform cleanup for
devices on the PCI bus and VDEV bus during eal_cleanup(). There would be an
ask for bus maintainers to add the relevant cleanup for their buses since
they have the domain expertise.

Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
Acked-by: Morten Brørup <mb@smartsharesystems.com>

---
v2:
* change log level from INFO to DEBUG for PCI cleanup
* add abignore entries for rte_bus related false positives

v3:
* add vdev bus cleanup
---
 devtools/libabigail.abignore    |  9 +++++++++
 drivers/bus/pci/pci_common.c    | 32 ++++++++++++++++++++++++++++++++
 drivers/bus/vdev/vdev.c         | 23 +++++++++++++++++++++++
 lib/eal/common/eal_common_bus.c | 18 ++++++++++++++++++
 lib/eal/include/rte_bus.h       | 23 +++++++++++++++++++++++
 lib/eal/linux/eal.c             |  1 +
 6 files changed, 106 insertions(+)

diff --git a/devtools/libabigail.abignore b/devtools/libabigail.abignore
index c618f20032..2ff482c086 100644
--- a/devtools/libabigail.abignore
+++ b/devtools/libabigail.abignore
@@ -40,3 +40,12 @@
 ; Ignore visibility fix of local functions in experimental gpudev library
 [suppress_file]
         soname_regexp = ^librte_gpudev\.
+
+; Ignore field inserted to rte_bus, adding cleanup function
+[suppress_type]
+        name = rte_bus
+        has_data_member_inserted_at = end
+
+; Ignore changes to internally used structs containing rte_bus
+[suppress_type]
+        name = rte_pci_bus, rte_vmbus_bus, rte_vdev_bus
diff --git a/drivers/bus/pci/pci_common.c b/drivers/bus/pci/pci_common.c
index 37ab879779..7d0c49f073 100644
--- a/drivers/bus/pci/pci_common.c
+++ b/drivers/bus/pci/pci_common.c
@@ -394,6 +394,37 @@ pci_probe(void)
 	return (probed && probed == failed) ? -1 : 0;
 }
 
+static int
+pci_cleanup(void)
+{
+	struct rte_pci_device *dev = NULL;
+	int ret = 0;
+
+	FOREACH_DEVICE_ON_PCIBUS(dev) {
+		struct rte_pci_addr *loc = &dev->addr;
+		struct rte_pci_driver *drv = dev->driver;
+
+		if (loc == NULL || drv == NULL)
+			continue;
+
+		RTE_LOG(DEBUG, EAL,
+				"Clean up PCI driver: %s (%x:%x) device: "PCI_PRI_FMT" (socket %i)\n",
+				drv->driver.name, dev->id.vendor_id, dev->id.device_id,
+				loc->domain, loc->bus, loc->devid, loc->function,
+				dev->device.numa_node);
+
+		ret = drv->remove(dev);
+		if (ret < 0) {
+			RTE_LOG(ERR, EAL, "Cleanup for device "PCI_PRI_FMT" failed\n",
+					dev->addr.domain, dev->addr.bus, dev->addr.devid,
+					dev->addr.function);
+			rte_errno = errno;
+		}
+	}
+
+	return ret;
+}
+
 /* dump one device */
 static int
 pci_dump_one_device(FILE *f, struct rte_pci_device *dev)
@@ -813,6 +844,7 @@ struct rte_pci_bus rte_pci_bus = {
 	.bus = {
 		.scan = rte_pci_scan,
 		.probe = pci_probe,
+		.cleanup = pci_cleanup,
 		.find_device = pci_find_device,
 		.plug = pci_plug,
 		.unplug = pci_unplug,
diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
index a8d8b2327e..eca1a3d536 100644
--- a/drivers/bus/vdev/vdev.c
+++ b/drivers/bus/vdev/vdev.c
@@ -569,6 +569,28 @@ vdev_probe(void)
 	return ret;
 }
 
+static int
+vdev_cleanup(void)
+{
+	struct rte_vdev_device *dev;
+	int ret = 0;
+
+	TAILQ_FOREACH(dev, &vdev_device_list, next) {
+		const char *name;
+		struct rte_vdev_driver *drv;
+
+		name = rte_vdev_device_name(dev);
+		if (vdev_parse(name, &drv))
+			continue;
+
+		ret = drv->remove(dev);
+		if (ret < 0)
+			VDEV_LOG(ERR, "Cleanup for device %s failed\n", rte_vdev_device_name(dev));
+	}
+
+	return ret;
+}
+
 struct rte_device *
 rte_vdev_find_device(const struct rte_device *start, rte_dev_cmp_t cmp,
 		     const void *data)
@@ -627,6 +649,7 @@ vdev_get_iommu_class(void)
 static struct rte_bus rte_vdev_bus = {
 	.scan = vdev_scan,
 	.probe = vdev_probe,
+	.cleanup = vdev_cleanup,
 	.find_device = rte_vdev_find_device,
 	.plug = vdev_plug,
 	.unplug = vdev_unplug,
diff --git a/lib/eal/common/eal_common_bus.c b/lib/eal/common/eal_common_bus.c
index baa5b532af..046a06a2bf 100644
--- a/lib/eal/common/eal_common_bus.c
+++ b/lib/eal/common/eal_common_bus.c
@@ -85,6 +85,24 @@ rte_bus_probe(void)
 	return 0;
 }
 
+/* Clean up all devices of all buses */
+int
+rte_bus_cleanup(void)
+{
+	int ret;
+	struct rte_bus *bus;
+
+	TAILQ_FOREACH(bus, &rte_bus_list, next) {
+		if (bus->cleanup == NULL)
+			continue;
+		ret = bus->cleanup();
+		if (ret)
+			RTE_LOG(ERR, EAL, "Bus (%s) cleanup failed.\n", bus->name);
+	}
+
+	return 0;
+}
+
 /* Dump information of a single bus */
 static int
 bus_dump_one(FILE *f, struct rte_bus *bus)
diff --git a/lib/eal/include/rte_bus.h b/lib/eal/include/rte_bus.h
index bbbb6efd28..42da38730f 100644
--- a/lib/eal/include/rte_bus.h
+++ b/lib/eal/include/rte_bus.h
@@ -66,6 +66,18 @@ typedef int (*rte_bus_scan_t)(void);
  */
 typedef int (*rte_bus_probe_t)(void);
 
+/**
+ * Implementation specific cleanup function which is responsible for cleaning up
+ * devices on that bus with applicable drivers.
+ *
+ * This is called while iterating over each registered bus.
+ *
+ * @return
+ * 0 for successful cleanup
+ * !0 for any error during cleanup
+ */
+typedef int (*rte_bus_cleanup_t)(void);
+
 /**
  * Device iterator to find a device on a bus.
  *
@@ -277,6 +289,7 @@ struct rte_bus {
 				/**< handle hot-unplug failure on the bus */
 	rte_bus_sigbus_handler_t sigbus_handler;
 					/**< handle sigbus error on the bus */
+	rte_bus_cleanup_t cleanup;   /**< Cleanup devices on bus */
 
 };
 
@@ -317,6 +330,16 @@ int rte_bus_scan(void);
  */
 int rte_bus_probe(void);
 
+/**
+ * For each device on the buses, perform a driver 'match' and call the
+ * driver-specific function for device cleanup.
+ *
+ * @return
+ * 0 for successful match/cleanup
+ * !0 otherwise
+ */
+int rte_bus_cleanup(void);
+
 /**
  * Dump information of all the buses registered with EAL.
  *
diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c
index 025e5cc10d..37983b98c0 100644
--- a/lib/eal/linux/eal.c
+++ b/lib/eal/linux/eal.c
@@ -1268,6 +1268,7 @@ rte_eal_cleanup(void)
 	vfio_mp_sync_cleanup();
 #endif
 	rte_mp_channel_cleanup();
+	rte_bus_cleanup();
 	/* after this point, any DPDK pointers will become dangling */
 	rte_eal_memory_detach();
 	eal_mp_dev_hotplug_cleanup();
-- 
2.31.1