[PATCH v3 3/5] nvme: add the NVME_ENABLE_MULTIPATH_PARAM config option

[John Meneghini <jmeneghi@redhat.com>]

The CONFIG_NVME_ENABLE_MULTIPATH_PARAM option controls the
core_nvme.multipath parameter. When CONFIG_NVME_ENABLE_MULTIPATH_PARAM=n
the multipath parameter is removed from the kernel and nvme multipathing
is permanently enabled.  When CONFIG_NVME_ENABLE_MULTIPATH_PARAM=y the
nvme multipath parameter is added to the kernel and nvme multipath
support is controlled by the core_nvme.multipath parameter.

By default CONFIG_NVME_ENABLE_MULTIPATH_PARAM=y

Signed-off-by: John Meneghini <jmeneghi@redhat.com>
Tested-by: John Meneghini <jmeneghi@redhat.com>
Reviewed-by: Bryan Gurney <bgurney@redhat.com>
---
 drivers/nvme/host/Kconfig     | 11 +++++++++++
 drivers/nvme/host/multipath.c |  2 ++
 2 files changed, 13 insertions(+)

diff --git a/drivers/nvme/host/Kconfig b/drivers/nvme/host/Kconfig
index d47dfa80fb95..8c04b6b93982 100644
--- a/drivers/nvme/host/Kconfig
+++ b/drivers/nvme/host/Kconfig
@@ -28,6 +28,17 @@ config NVME_MULTIPATH
 
 	  If unsure, say Y.
 
+config NVME_ENABLE_MULTIPATH_PARAM
+	bool "NVMe enable multipath param"
+	depends on NVME_CORE && NVME_MULTIPATH
+	default y
+	help
+	  This option enables the core_nvme.multipath parameter.
+	  If this option is disabled the core_nvme.multipath parameter
+	  is excluded from the kernel.
+
+	  If unsure, say Y.
+
 config NVME_VERBOSE_ERRORS
 	bool "NVMe verbose error reporting"
 	depends on NVME_CORE
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 6b12ca80aa27..83084093e8db 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -10,9 +10,11 @@
 #include "nvme.h"
 
 bool multipath = true;
+#ifdef CONFIG_NVME_ENABLE_MULTIPATH_PARAM
 module_param(multipath, bool, 0444);
 MODULE_PARM_DESC(multipath,
 	"turn on native support for multiple controllers per subsystem");
+#endif
 
 static const char *nvme_iopolicy_names[] = {
 	[NVME_IOPOLICY_NUMA]	= "numa",
-- 
2.48.1