[PATCH v3 1/2] dax: introduce CONFIG_DAX_DRIVER

Dan Williams
2017-08-02T18:02:18Z

In support of allowing device-mapper to compile out idle/dead code when
there are no dax providers in the system, introduce the DAX_DRIVER
symbol. This is selected by all leaf drivers that device-mapper might be
layered on top. This allows device-mapper to 'select DAX', i.e. upgrade
it from DAX=m to DAX=y, when a provider is present.

Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Bart Van Assche <Bart.VanAssche@wdc.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
arch/powerpc/platforms/Kconfig | 1 +
drivers/block/Kconfig | 1 +
drivers/dax/Kconfig | 4 +++-
drivers/nvdimm/Kconfig | 1 +
drivers/s390/block/Kconfig | 1 +
5 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 4fd64d3f5c44..4561340c1f92 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -296,6 +296,7 @@ config AXON_RAM
tristate "Axon DDR2 memory device driver"
depends on PPC_IBM_CELL_BLADE && BLOCK
select DAX
+ select DAX_DRIVER
default m
help
It registers one block device per Axon's DDR2 memory bank found
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 8ddc98279c8f..e1b6f4d2a716 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -324,6 +324,7 @@ config BLK_DEV_SX8
config BLK_DEV_RAM
tristate "RAM block device support"
select DAX if BLK_DEV_RAM_DAX
+ select DAX_DRIVER if BLK_DEV_RAM_DAX
---help---
Saying Y here will allow you to use a portion of your RAM memory as
a block device, so that you can make file systems on it, read and
diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig
index b79aa8f7a497..9bf940eb9c06 100644
--- a/drivers/dax/Kconfig
+++ b/drivers/dax/Kconfig
@@ -1,3 +1,6 @@
+config DAX_DRIVER
+ bool
+
menuconfig DAX
tristate "DAX: direct access to differentiated memory"
select SRCU
@@ -16,7 +19,6 @@ config DEV_DAX
baseline memory pool. Mappings of a /dev/daxX.Y device impose
restrictions that make the mapping behavior deterministic.

-
config DEV_DAX_PMEM
tristate "PMEM DAX: direct access to persistent memory"
depends on LIBNVDIMM && NVDIMM_DAX && DEV_DAX
diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index 5bdd499b5f4f..afe4018d76cf 100644
--- a/drivers/nvdimm/Kconfig
+++ b/drivers/nvdimm/Kconfig
@@ -21,6 +21,7 @@ config BLK_DEV_PMEM
tristate "PMEM: Persistent memory block device support"
default LIBNVDIMM
select DAX
+ select DAX_DRIVER
select ND_BTT if BTT
select ND_PFN if NVDIMM_PFN
help
diff --git a/drivers/s390/block/Kconfig b/drivers/s390/block/Kconfig
index 31f014b57bfc..3f563f2f33d6 100644
--- a/drivers/s390/block/Kconfig
+++ b/drivers/s390/block/Kconfig
@@ -15,6 +15,7 @@ config BLK_DEV_XPRAM
config DCSSBLK
def_tristate m
select DAX
+ select DAX_DRIVER
prompt "DCSSBLK support"
depends on S390 && BLOCK
help