init: defer component init in EAL init

Signed-off-by: David Marchand <[email protected]>

lib/eal/linux/eal.c

@@ -927,6 +927,8 @@ rte_eal_init(int argc, char **argv)
 	struct internal_config *internal_conf =
 		eal_get_internal_configuration();
 
+	eal_init_early();
+
 	/* setup log as early as possible */
 	if (eal_parse_log_options(argc, argv) < 0) {
 		rte_eal_init_alert("invalid log arguments.");

lib/init/meson.build

@@ -1,4 +1,6 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # Copyright (c) 2024 Red Hat, Inc.
 
+includes += global_inc
+sources = files('rte_init.c')
 headers = files('rte_init.h')

lib/init/rte_init.c

@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (c) 2024 Red Hat, Inc.
+ */
+
+#include <stdbool.h>
+#include <sys/queue.h>
+
+#include <rte_os.h>
+
+#include <rte_common.h>
+#include <rte_init.h>
+
+static bool init_called;
+
+static TAILQ_HEAD(, rte_init) init_list = TAILQ_HEAD_INITIALIZER(init_list);
+
+void
+rte_init_register(struct rte_init *i)
+{
+	struct rte_init *p;
+
+	/*
+	 * This code has been invoked after rte_eal_init() (common case is with drivers loaded
+	 * as shared libraries).
+	 */
+	if (init_called) {
+		i->callback();
+		return;
+	}
+
+	TAILQ_FOREACH(p, &init_list, next) {
+		if (i->priority >= p->priority)
+			continue;
+		TAILQ_INSERT_BEFORE(p, i, next);
+		return;
+	}
+
+	TAILQ_INSERT_TAIL(&init_list, i, next);
+}
+
+void
+eal_init_early(void)
+{
+	struct rte_init *i;
+
+	init_called = true;
+
+	TAILQ_FOREACH(i, &init_list, next)
+		i->callback();
+}

lib/init/rte_init.h

@@ -5,6 +5,24 @@
 #ifndef RTE_INIT_H
 #define RTE_INIT_H
 
+#include <sys/queue.h>
+
+#include <rte_os.h>
+
+#include <rte_compat.h>
+
+struct rte_init {
+	TAILQ_ENTRY(rte_init) next;
+	unsigned int priority;
+	void (*callback)(void);
+};
+void
+rte_init_register(struct rte_init *i);
+
+__rte_internal
+void
+eal_init_early(void);
+
 #define RTE_PRIORITY_LOG 101
 #define RTE_PRIORITY_BUS 110
 #define RTE_PRIORITY_CLASS 120
@@ -25,7 +43,16 @@
 #ifndef RTE_INIT_PRIO /* Allow to override from EAL */
 #ifndef RTE_TOOLCHAIN_MSVC
 #define RTE_INIT_PRIO(func, prio) \
-static void __attribute__((constructor(RTE_PRIO(prio)), used)) func(void)
+static void func(void); \
+static struct rte_init init_obj_ ## func; \
+static void __attribute__((constructor(RTE_PRIO(prio)), used)) init_ ## func(void) \
+{ \
+	struct rte_init *i = &init_obj_ ## func; \
+	i->callback = func; \
+	i->priority = RTE_PRIO(prio); \
+	rte_init_register(i); \
+} \
+static void func(void)
 #else
 /* definition from the Microsoft CRT */
 typedef int(__cdecl *_PIFV)(void);

lib/init/version.map

@@ -1,3 +1,13 @@
 DPDK_25 {
+	global:
+
+	rte_init_register;
+
 	local: *;
 };
+
+INTERNAL {
+	global:
+
+	eal_init_early;
+};