[dpdk-dev] [PATCH v3 01/14] eal: add API to lock/unlock memory hotplug

[Anatoly Burakov]

Currently, the memory hotplug is locked automatically by all
memory-related _walk() functions, but sometimes locking the
memory subsystem outside of them is needed. There is no
public API to do that, so it creates a dependency on shared
memory config to be public. Fix this by introducing a new
API to lock/unlock the memory hotplug subsystem.

Create a new common file for all things mem config, and a
new API namespace rte_mcfg_*.

Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
---
 lib/librte_eal/common/eal_common_mcfg.c       | 34 +++++++++++++++++++
 .../common/include/rte_eal_memconfig.h        | 24 +++++++++++++
 lib/librte_eal/common/meson.build             |  1 +
 lib/librte_eal/freebsd/eal/Makefile           |  1 +
 lib/librte_eal/linux/eal/Makefile             |  1 +
 lib/librte_eal/rte_eal_version.map            |  4 +++
 6 files changed, 65 insertions(+)
 create mode 100644 lib/librte_eal/common/eal_common_mcfg.c

diff --git a/lib/librte_eal/common/eal_common_mcfg.c b/lib/librte_eal/common/eal_common_mcfg.c
new file mode 100644
index 000000000..985d36cc2
--- /dev/null
+++ b/lib/librte_eal/common/eal_common_mcfg.c
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2019 Intel Corporation
+ */
+
+#include <rte_config.h>
+#include <rte_eal_memconfig.h>
+
+void
+rte_mcfg_mem_read_lock(void)
+{
+	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+	rte_rwlock_read_lock(&mcfg->memory_hotplug_lock);
+}
+
+void
+rte_mcfg_mem_read_unlock(void)
+{
+	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+	rte_rwlock_read_unlock(&mcfg->memory_hotplug_lock);
+}
+
+void
+rte_mcfg_mem_write_lock(void)
+{
+	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+	rte_rwlock_write_lock(&mcfg->memory_hotplug_lock);
+}
+
+void
+rte_mcfg_mem_write_unlock(void)
+{
+	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+	rte_rwlock_write_unlock(&mcfg->memory_hotplug_lock);
+}
diff --git a/lib/librte_eal/common/include/rte_eal_memconfig.h b/lib/librte_eal/common/include/rte_eal_memconfig.h
index 84aabe36c..a554518ef 100644
--- a/lib/librte_eal/common/include/rte_eal_memconfig.h
+++ b/lib/librte_eal/common/include/rte_eal_memconfig.h
@@ -100,6 +100,30 @@ rte_eal_mcfg_wait_complete(struct rte_mem_config* mcfg)
 		rte_pause();
 }
 
+/**
+ * Lock the internal EAL shared memory configuration for shared access.
+ */
+void
+rte_mcfg_mem_read_lock(void);
+
+/**
+ * Unlock the internal EAL shared memory configuration for shared access.
+ */
+void
+rte_mcfg_mem_read_unlock(void);
+
+/**
+ * Lock the internal EAL shared memory configuration for exclusive access.
+ */
+void
+rte_mcfg_mem_write_lock(void);
+
+/**
+ * Unlock the internal EAL shared memory configuration for exclusive access.
+ */
+void
+rte_mcfg_mem_write_unlock(void);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/librte_eal/common/meson.build b/lib/librte_eal/common/meson.build
index 0670e4102..710168b29 100644
--- a/lib/librte_eal/common/meson.build
+++ b/lib/librte_eal/common/meson.build
@@ -18,6 +18,7 @@ common_sources = files(
 	'eal_common_launch.c',
 	'eal_common_lcore.c',
 	'eal_common_log.c',
+	'eal_common_mcfg.c',
 	'eal_common_memalloc.c',
 	'eal_common_memory.c',
 	'eal_common_memzone.c',
diff --git a/lib/librte_eal/freebsd/eal/Makefile b/lib/librte_eal/freebsd/eal/Makefile
index 19854ee2c..dc56af582 100644
--- a/lib/librte_eal/freebsd/eal/Makefile
+++ b/lib/librte_eal/freebsd/eal/Makefile
@@ -44,6 +44,7 @@ SRCS-$(CONFIG_RTE_EXEC_ENV_FREEBSD) += eal_common_timer.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_FREEBSD) += eal_common_memzone.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_FREEBSD) += eal_common_log.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_FREEBSD) += eal_common_launch.c
+SRCS-$(CONFIG_RTE_EXEC_ENV_FREEBSD) += eal_common_mcfg.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_FREEBSD) += eal_common_memalloc.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_FREEBSD) += eal_common_memory.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_FREEBSD) += eal_common_tailqs.c
diff --git a/lib/librte_eal/linux/eal/Makefile b/lib/librte_eal/linux/eal/Makefile
index 6e5261152..3b2642eb8 100644
--- a/lib/librte_eal/linux/eal/Makefile
+++ b/lib/librte_eal/linux/eal/Makefile
@@ -52,6 +52,7 @@ SRCS-$(CONFIG_RTE_EXEC_ENV_LINUX) += eal_common_timer.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_LINUX) += eal_common_memzone.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_LINUX) += eal_common_log.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_LINUX) += eal_common_launch.c
+SRCS-$(CONFIG_RTE_EXEC_ENV_LINUX) += eal_common_mcfg.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_LINUX) += eal_common_memalloc.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_LINUX) += eal_common_memory.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_LINUX) += eal_common_tailqs.c
diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map
index 824edf0ff..faad879db 100644
--- a/lib/librte_eal/rte_eal_version.map
+++ b/lib/librte_eal/rte_eal_version.map
@@ -292,6 +292,10 @@ DPDK_19.08 {
 
 	rte_lcore_index;
 	rte_lcore_to_socket_id;
+	rte_mcfg_mem_read_lock;
+	rte_mcfg_mem_read_unlock;
+	rte_mcfg_mem_write_lock;
+	rte_mcfg_mem_write_unlock;
 
 } DPDK_19.05;
 
-- 
2.17.1