[dpdk-dev] [PATCH V9 2/5] eal: add uevent pass and process function

Jeff Guo jia.guo at intel.com
Wed Jan 10 10:12:21 CET 2018


In order to handle the uevent which have been detected from the kernel side,
add uevent process function, let hot plug event to be example to show uevent
mechanism how to pass the uevent and process the uevent.

About uevent passing and processing, add below functions in linux eal dev layer.
FreeBSD not support uevent ,so let it to be void and do not implement in function.
a.dev_uev_parse
b.dev_uev_receive
c.dev_uev_process

Signed-off-by: Jeff Guo <jia.guo at intel.com>
---
v9->v8:
split the patch set into small and explicit patch
---
 drivers/bus/pci/pci_common.c            |  20 ++++++
 drivers/bus/vdev/vdev.c                 |  20 ++++++
 lib/librte_eal/common/eal_common_bus.c  |  28 ++++++++
 lib/librte_eal/common/include/rte_bus.h |  36 ++++++++++
 lib/librte_eal/common/include/rte_dev.h |  21 ++++++
 lib/librte_eal/linuxapp/eal/eal_dev.c   | 120 +++++++++++++++++++++++++++++++-
 6 files changed, 243 insertions(+), 2 deletions(-)

diff --git a/drivers/bus/pci/pci_common.c b/drivers/bus/pci/pci_common.c
index 104fdf9..c4415a0 100644
--- a/drivers/bus/pci/pci_common.c
+++ b/drivers/bus/pci/pci_common.c
@@ -502,6 +502,25 @@ pci_find_device(const struct rte_device *start, rte_dev_cmp_t cmp,
 	return NULL;
 }
 
+static struct rte_device *
+pci_find_device_by_name(const struct rte_device *start,
+		rte_dev_cmp_name_t cmp_name,
+		const void *data)
+{
+	struct rte_pci_device *dev;
+
+	FOREACH_DEVICE_ON_PCIBUS(dev) {
+		if (start && &dev->device == start) {
+			start = NULL; /* starting point found */
+			continue;
+		}
+		if (cmp_name(dev->device.name, data) == 0)
+			return &dev->device;
+	}
+
+	return NULL;
+}
+
 static int
 pci_plug(struct rte_device *dev)
 {
@@ -528,6 +547,7 @@ struct rte_pci_bus rte_pci_bus = {
 		.scan = rte_pci_scan,
 		.probe = rte_pci_probe,
 		.find_device = pci_find_device,
+		.find_device_by_name = pci_find_device_by_name,
 		.plug = pci_plug,
 		.unplug = pci_unplug,
 		.parse = pci_parse,
diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
index fd7736d..cac2aa0 100644
--- a/drivers/bus/vdev/vdev.c
+++ b/drivers/bus/vdev/vdev.c
@@ -323,6 +323,25 @@ vdev_find_device(const struct rte_device *start, rte_dev_cmp_t cmp,
 	return NULL;
 }
 
+
+static struct rte_device *
+vdev_find_device_by_name(const struct rte_device *start,
+		rte_dev_cmp_name_t cmp_name,
+		const void *data)
+{
+	struct rte_vdev_device *dev;
+
+	TAILQ_FOREACH(dev, &vdev_device_list, next) {
+		if (start && &dev->device == start) {
+			start = NULL;
+			continue;
+		}
+		if (cmp_name(dev->device.name, data) == 0)
+			return &dev->device;
+	}
+	return NULL;
+}
+
 static int
 vdev_plug(struct rte_device *dev)
 {
@@ -339,6 +358,7 @@ static struct rte_bus rte_vdev_bus = {
 	.scan = vdev_scan,
 	.probe = vdev_probe,
 	.find_device = vdev_find_device,
+	.find_device_by_name = vdev_find_device_by_name,
 	.plug = vdev_plug,
 	.unplug = vdev_unplug,
 	.parse = vdev_parse,
diff --git a/lib/librte_eal/common/eal_common_bus.c b/lib/librte_eal/common/eal_common_bus.c
index 3e022d5..efd5539 100644
--- a/lib/librte_eal/common/eal_common_bus.c
+++ b/lib/librte_eal/common/eal_common_bus.c
@@ -51,6 +51,7 @@ rte_bus_register(struct rte_bus *bus)
 	RTE_VERIFY(bus->scan);
 	RTE_VERIFY(bus->probe);
 	RTE_VERIFY(bus->find_device);
+	RTE_VERIFY(bus->find_device_by_name);
 	/* Buses supporting driver plug also require unplug. */
 	RTE_VERIFY(!bus->plug || bus->unplug);
 
@@ -170,6 +171,14 @@ cmp_rte_device(const struct rte_device *dev1, const void *_dev2)
 }
 
 static int
+cmp_rte_device_name(const char *dev_name1, const void *_dev_name2)
+{
+	const char *dev_name2 = _dev_name2;
+
+	return strcmp(dev_name1, dev_name2);
+}
+
+static int
 bus_find_device(const struct rte_bus *bus, const void *_dev)
 {
 	struct rte_device *dev;
@@ -178,6 +187,25 @@ bus_find_device(const struct rte_bus *bus, const void *_dev)
 	return dev == NULL;
 }
 
+static struct rte_device *
+bus_find_device_by_name(const struct rte_bus *bus, const void *_dev_name)
+{
+	struct rte_device *dev;
+
+	dev = bus->find_device_by_name(NULL, cmp_rte_device_name, _dev_name);
+	return dev;
+}
+
+struct rte_device *
+
+rte_bus_find_device(const struct rte_bus *bus, const void *_dev_name)
+{
+	struct rte_device *dev;
+
+	dev = bus_find_device_by_name(bus, _dev_name);
+	return dev;
+}
+
 struct rte_bus *
 rte_bus_find_by_device(const struct rte_device *dev)
 {
diff --git a/lib/librte_eal/common/include/rte_bus.h b/lib/librte_eal/common/include/rte_bus.h
index 6fb0834..6dcfdb3 100644
--- a/lib/librte_eal/common/include/rte_bus.h
+++ b/lib/librte_eal/common/include/rte_bus.h
@@ -122,6 +122,34 @@ typedef struct rte_device *
 			 const void *data);
 
 /**
+ * Device iterator to find a device on a bus.
+ *
+ * This function returns an rte_device if one of those held by the bus
+ * matches the data passed as parameter.
+ *
+ * If the comparison function returns zero this function should stop iterating
+ * over any more devices. To continue a search the device of a previous search
+ * can be passed via the start parameter.
+ *
+ * @param cmp
+ *	the device name comparison function.
+ *
+ * @param data
+ *	Data to compare each device against.
+ *
+ * @param start
+ *	starting point for the iteration
+ *
+ * @return
+ *	The first device matching the data, NULL if none exists.
+ */
+typedef struct rte_device *
+(*rte_bus_find_device_by_name_t)(const struct rte_device *start,
+			 rte_dev_cmp_name_t cmp,
+			 const void *data);
+
+
+/**
  * Implementation specific probe function which is responsible for linking
  * devices on that bus with applicable drivers.
  *
@@ -206,6 +234,8 @@ struct rte_bus {
 	rte_bus_scan_t scan;         /**< Scan for devices attached to bus */
 	rte_bus_probe_t probe;       /**< Probe devices on bus */
 	rte_bus_find_device_t find_device; /**< Find a device on the bus */
+	rte_bus_find_device_by_name_t find_device_by_name;
+				     /**< Find a device on the bus */
 	rte_bus_plug_t plug;         /**< Probe single device for drivers */
 	rte_bus_unplug_t unplug;     /**< Remove single device from driver */
 	rte_bus_parse_t parse;       /**< Parse a device name */
@@ -306,6 +336,12 @@ struct rte_bus *rte_bus_find(const struct rte_bus *start, rte_bus_cmp_t cmp,
 struct rte_bus *rte_bus_find_by_device(const struct rte_device *dev);
 
 /**
+ * Find the registered bus for a particular device.
+ */
+struct rte_device *rte_bus_find_device(const struct rte_bus *bus,
+				const void *dev_name);
+
+/**
  * Find the registered bus for a given name.
  */
 struct rte_bus *rte_bus_find_by_name(const char *busname);
diff --git a/lib/librte_eal/common/include/rte_dev.h b/lib/librte_eal/common/include/rte_dev.h
index ab12862..d394ad3 100644
--- a/lib/librte_eal/common/include/rte_dev.h
+++ b/lib/librte_eal/common/include/rte_dev.h
@@ -53,10 +53,28 @@ extern "C" {
 
 #include <exec-env/rte_dev.h>
 
+#define RTE_EAL_UEV_MSG_LEN 4096
+#define RTE_EAL_UEV_MSG_ELEM_LEN 128
+
+enum rte_dev_state {
+	RTE_DEV_UNDEFINED,	/**< unknown device state */
+	RTE_DEV_FAULT,	/**< device fault or error */
+	RTE_DEV_PARSED,	/**< device have been parsed on bus*/
+	RTE_DEV_PROBED,	/**< devcie have been probed driver  */
+};
+
+enum uev_subsystem {
+	UEV_SUBSYSTEM_UIO,
+	UEV_SUBSYSTEM_VFIO,
+	UEV_SUBSYSTEM_PCI,
+	UEV_SUBSYSTEM_MAX
+};
+
 enum uev_monitor_netlink_group {
 	UEV_MONITOR_KERNEL,
 	UEV_MONITOR_UDEV,
 };
+
 /**
  * The device event type.
  */
@@ -204,6 +222,7 @@ struct rte_device {
 	const struct rte_driver *driver;/**< Associated driver */
 	int numa_node;                /**< NUMA node connection */
 	struct rte_devargs *devargs;  /**< Device user arguments */
+	enum rte_dev_state state;  /**< Device state */
 	/** User application callbacks for device event */
 	struct rte_eal_dev_cb_list uev_cbs;
 };
@@ -288,6 +307,8 @@ int rte_eal_hotplug_remove(const char *busname, const char *devname);
  */
 typedef int (*rte_dev_cmp_t)(const struct rte_device *dev, const void *data);
 
+typedef int (*rte_dev_cmp_name_t)(const char *dev_name, const void *data);
+
 #define RTE_PMD_EXPORT_NAME_ARRAY(n, idx) n##idx[]
 
 #define RTE_PMD_EXPORT_NAME(name, idx) \
diff --git a/lib/librte_eal/linuxapp/eal/eal_dev.c b/lib/librte_eal/linuxapp/eal/eal_dev.c
index 4812dbc..9d347f2 100644
--- a/lib/librte_eal/linuxapp/eal/eal_dev.c
+++ b/lib/librte_eal/linuxapp/eal/eal_dev.c
@@ -79,10 +79,126 @@ dev_monitor_enable(int netlink_fd)
 	return -1;
 }
 
+static void
+dev_uev_parse(const char *buf, struct rte_eal_uevent *event)
+{
+	char action[RTE_EAL_UEV_MSG_ELEM_LEN];
+	char subsystem[RTE_EAL_UEV_MSG_ELEM_LEN];
+	char dev_path[RTE_EAL_UEV_MSG_ELEM_LEN];
+	char pci_slot_name[RTE_EAL_UEV_MSG_ELEM_LEN];
+	int i = 0;
+
+	memset(action, 0, RTE_EAL_UEV_MSG_ELEM_LEN);
+	memset(subsystem, 0, RTE_EAL_UEV_MSG_ELEM_LEN);
+	memset(dev_path, 0, RTE_EAL_UEV_MSG_ELEM_LEN);
+	memset(pci_slot_name, 0, RTE_EAL_UEV_MSG_ELEM_LEN);
+
+	while (i < RTE_EAL_UEV_MSG_LEN) {
+		for (; i < RTE_EAL_UEV_MSG_LEN; i++) {
+			if (*buf)
+				break;
+			buf++;
+		}
+		if (!strncmp(buf, "libudev", 7)) {
+			buf += 7;
+			i += 7;
+			event->group = UEV_MONITOR_UDEV;
+		}
+		if (!strncmp(buf, "ACTION=", 7)) {
+			buf += 7;
+			i += 7;
+			snprintf(action, sizeof(action), "%s", buf);
+		} else if (!strncmp(buf, "DEVPATH=", 8)) {
+			buf += 8;
+			i += 8;
+			snprintf(dev_path, sizeof(dev_path), "%s", buf);
+		} else if (!strncmp(buf, "SUBSYSTEM=", 10)) {
+			buf += 10;
+			i += 10;
+			snprintf(subsystem, sizeof(subsystem), "%s", buf);
+		} else if (!strncmp(buf, "PCI_SLOT_NAME=", 14)) {
+			buf += 14;
+			i += 14;
+			snprintf(pci_slot_name, sizeof(subsystem), "%s", buf);
+			event->devname = pci_slot_name;
+		}
+		for (; i < RTE_EAL_UEV_MSG_LEN; i++) {
+			if (*buf == '\0')
+				break;
+			buf++;
+		}
+	}
+
+	if (!strncmp(subsystem, "pci", 3))
+		event->subsystem = UEV_SUBSYSTEM_PCI;
+	if (!strncmp(action, "add", 3))
+		event->type = RTE_DEV_EVENT_ADD;
+	if (!strncmp(action, "remove", 6))
+		event->type = RTE_DEV_EVENT_REMOVE;
+	event->devname = pci_slot_name;
+}
+
 static int
-dev_uev_process(__rte_unused struct epoll_event *events, __rte_unused int nfds)
+dev_uev_receive(int fd, struct rte_eal_uevent *uevent)
 {
-	/* TODO: device uevent processing */
+	int ret;
+	char buf[RTE_EAL_UEV_MSG_LEN];
+
+	memset(uevent, 0, sizeof(struct rte_eal_uevent));
+	memset(buf, 0, RTE_EAL_UEV_MSG_LEN);
+
+	ret = recv(fd, buf, RTE_EAL_UEV_MSG_LEN - 1, MSG_DONTWAIT);
+	if (ret < 0) {
+		RTE_LOG(ERR, EAL,
+		"Socket read error(%d): %s\n",
+		errno, strerror(errno));
+		return -1;
+	} else if (ret == 0)
+		/* connection closed */
+		return -1;
+
+	dev_uev_parse(buf, uevent);
+
+	return 0;
+}
+
+static int
+dev_uev_process(struct epoll_event *events, int nfds)
+{
+	struct rte_bus *bus;
+	struct rte_device *dev;
+	struct rte_eal_uevent uevent;
+	int i;
+
+	for (i = 0; i < nfds; i++) {
+		/**
+		 * check device uevent from kernel side, no need to check
+		 * uevent from udev.
+		 */
+		if ((dev_uev_receive(events[i].data.fd, &uevent)) ||
+			(uevent.group == UEV_MONITOR_UDEV))
+			return 0;
+
+		/* default handle all pci devcie when is being hot plug */
+		if (uevent.subsystem == UEV_SUBSYSTEM_PCI) {
+			bus = rte_bus_find_by_name("pci");
+			dev = rte_bus_find_device(bus, uevent.devname);
+			if (uevent.type == RTE_DEV_EVENT_REMOVE) {
+
+				if ((!dev) || dev->state == RTE_DEV_UNDEFINED)
+					return 0;
+				return(_rte_dev_callback_process(dev,
+				  RTE_DEV_EVENT_REMOVE,
+				  NULL));
+			} else if (uevent.type == RTE_DEV_EVENT_ADD) {
+				if (dev == NULL) {
+					return(_rte_dev_callback_process(NULL,
+					  RTE_DEV_EVENT_ADD,
+					  uevent.devname));
+				}
+			}
+		}
+	}
 	return 0;
 }
 
-- 
2.7.4



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