[dpdk-dev] [PATCH V10 2/2] eal: add uevent pass and process function

Jeff Guo jia.guo at intel.com
Thu Jan 11 15:05:34 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>
---
V10->V9:
delete some unuse part
---
 lib/librte_eal/common/include/rte_dev.h |  23 +++++++
 lib/librte_eal/linuxapp/eal/eal_dev.c   | 109 +++++++++++++++++++++++++++++++-
 2 files changed, 130 insertions(+), 2 deletions(-)

diff --git a/lib/librte_eal/common/include/rte_dev.h b/lib/librte_eal/common/include/rte_dev.h
index fea037a..a3166f7 100644
--- a/lib/librte_eal/common/include/rte_dev.h
+++ b/lib/librte_eal/common/include/rte_dev.h
@@ -51,6 +51,23 @@ extern "C" {
 
 #include <rte_log.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 rte_dev_subsystem {
+	RTE_DEV_SUBSYSTEM_UIO,
+	RTE_DEV_SUBSYSTEM_VFIO,
+	RTE_DEV_SUBSYSTEM_PCI,
+	RTE_DEV_SUBSYSTEM_MAX
+};
+
 /**
  * The device event type.
  */
@@ -61,10 +78,16 @@ enum rte_dev_event_type {
 	RTE_DEV_EVENT_MAX	/**< max value of this enum */
 };
 
+enum event_monitor_netlink_group {
+	RTE_DEV_EVENT_MONITOR_KERNEL,
+	RTE_DEV_EVENT_MONITOR_UDEV,
+};
+
 struct rte_dev_event {
 	enum rte_dev_event_type type;	/**< device event type */
 	int subsystem;				/**< subsystem id */
 	char *devname;				/**< device name */
+	enum event_monitor_netlink_group group;	/**< device netlink group */
 };
 
 typedef int (*rte_dev_event_cb_fn)(enum rte_dev_event_type event,
diff --git a/lib/librte_eal/linuxapp/eal/eal_dev.c b/lib/librte_eal/linuxapp/eal/eal_dev.c
index bc32aab..1d0ec33 100644
--- a/lib/librte_eal/linuxapp/eal/eal_dev.c
+++ b/lib/librte_eal/linuxapp/eal/eal_dev.c
@@ -79,10 +79,115 @@ dev_monitor_enable(int netlink_fd)
 	return -1;
 }
 
+static void
+dev_uev_parse(const char *buf, struct rte_dev_event *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 = RTE_DEV_EVENT_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 = RTE_DEV_SUBSYSTEM_UIO;
+	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_receive(int fd, struct rte_dev_event *uevent)
+{
+	int ret;
+	char buf[RTE_EAL_UEV_MSG_LEN];
+
+	memset(uevent, 0, sizeof(struct rte_dev_event));
+	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(__rte_unused struct epoll_event *events, __rte_unused int nfds)
+dev_uev_process(struct epoll_event *events, int nfds)
 {
-	/* TODO: device uevent processing */
+	struct rte_dev_event 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 == RTE_DEV_EVENT_MONITOR_UDEV))
+			return 0;
+
+		/* default handle all pci devcie when is being hot plug */
+		if (uevent.subsystem == RTE_DEV_SUBSYSTEM_UIO) {
+			if (uevent.type == RTE_DEV_EVENT_REMOVE) {
+				return(_rte_dev_callback_process(NULL,
+				  RTE_DEV_EVENT_REMOVE));
+			} else if (uevent.type == RTE_DEV_EVENT_ADD) {
+				return(_rte_dev_callback_process(NULL,
+				  RTE_DEV_EVENT_ADD));
+			}
+		}
+	}
 	return 0;
 }
 
-- 
2.7.4



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