IB: Allow build of hw/ and ulp/ subdirectories independently

It is not possible to build only the drivers/infiniband/hw/ (or ulp/)
subdirectory with command such as:

    $ make ARCH=x86_64 O=./obj-x86_64/ drivers/infiniband/hw/

This fails with following error messages:

    make[2]: Nothing to be done for `all'.
    make[2]: Nothing to be done for `relocs'.
      CHK     include/config/kernel.release
      Using /home/ydroneaud/src/linux as source for kernel
      GEN     /home/ydroneaud/src/linux/obj-x86_64/Makefile
      CHK     include/generated/uapi/linux/version.h
      CHK     include/generated/utsrelease.h
      CALL    /home/ydroneaud/src/linux/scripts/checksyscalls.sh
    /home/ydroneaud/src/linux/scripts/Makefile.build:44: /home/ydroneaud/src/linux/drivers/infiniband/hw/Makefile: No such file or directory
    make[2]: *** No rule to make target `/home/ydroneaud/src/linux/drivers/infiniband/hw/Makefile'.  Stop.
    make[1]: *** [drivers/infiniband/hw/] Error 2
    make: *** [sub-make] Error 2

This patch creates a Makefile in hw/ and ulp/ and moves each
corresponding parts of drivers/infiniband/Makefile in the new
Makefiles.

It should not break build except if some hw/ drivers or ulp/ were
allowed previously to be built while CONFIG_INFINIBAND is set to 'n',
but according to drivers/infiniband/Kconfig, it's not possible. So it
should be safe to apply.

Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

3 files changed, 19 insertions, 17 deletions

diff --git a/drivers/infiniband/Makefile b/drivers/infiniband/Makefile
index bf508b5550c4..dc21836b5a8d 100644
--- a/drivers/infiniband/Makefile
+++ b/drivers/infiniband/Makefile
@@ -1,18 +1,3 @@
 obj-$(CONFIG_INFINIBAND)                += core/
-obj-$(CONFIG_INFINIBAND_MTHCA)          += hw/mthca/
-obj-$(CONFIG_INFINIBAND_IPATH)          += hw/ipath/
-obj-$(CONFIG_INFINIBAND_QIB)            += hw/qib/
-obj-$(CONFIG_INFINIBAND_EHCA)           += hw/ehca/
-obj-$(CONFIG_INFINIBAND_AMSO1100)       += hw/amso1100/
-obj-$(CONFIG_INFINIBAND_CXGB3)          += hw/cxgb3/
-obj-$(CONFIG_INFINIBAND_CXGB4)          += hw/cxgb4/
-obj-$(CONFIG_MLX4_INFINIBAND)           += hw/mlx4/
-obj-$(CONFIG_MLX5_INFINIBAND)           += hw/mlx5/
-obj-$(CONFIG_INFINIBAND_NES)            += hw/nes/
-obj-$(CONFIG_INFINIBAND_OCRDMA)         += hw/ocrdma/
-obj-$(CONFIG_INFINIBAND_USNIC)          += hw/usnic/
-obj-$(CONFIG_INFINIBAND_IPOIB)          += ulp/ipoib/
-obj-$(CONFIG_INFINIBAND_SRP)            += ulp/srp/
-obj-$(CONFIG_INFINIBAND_SRPT)           += ulp/srpt/
-obj-$(CONFIG_INFINIBAND_ISER)           += ulp/iser/
-obj-$(CONFIG_INFINIBAND_ISERT)          += ulp/isert/
+obj-$(CONFIG_INFINIBAND)                += hw/
+obj-$(CONFIG_INFINIBAND)                += ulp/
diff --git a/drivers/infiniband/hw/Makefile b/drivers/infiniband/hw/Makefile
new file mode 100644
index 000000000000..e900b03531a9
--- /dev/null
+++ b/drivers/infiniband/hw/Makefile
@@ -0,0 +1,12 @@
+obj-$(CONFIG_INFINIBAND_MTHCA)          += mthca/
+obj-$(CONFIG_INFINIBAND_IPATH)          += ipath/
+obj-$(CONFIG_INFINIBAND_QIB)            += qib/
+obj-$(CONFIG_INFINIBAND_EHCA)           += ehca/
+obj-$(CONFIG_INFINIBAND_AMSO1100)       += amso1100/
+obj-$(CONFIG_INFINIBAND_CXGB3)          += cxgb3/
+obj-$(CONFIG_INFINIBAND_CXGB4)          += cxgb4/
+obj-$(CONFIG_MLX4_INFINIBAND)           += mlx4/
+obj-$(CONFIG_MLX5_INFINIBAND)           += mlx5/
+obj-$(CONFIG_INFINIBAND_NES)            += nes/
+obj-$(CONFIG_INFINIBAND_OCRDMA)         += ocrdma/
+obj-$(CONFIG_INFINIBAND_USNIC)          += usnic/
diff --git a/drivers/infiniband/ulp/Makefile b/drivers/infiniband/ulp/Makefile
new file mode 100644
index 000000000000..f3c7dcf03098
--- /dev/null
+++ b/drivers/infiniband/ulp/Makefile
@@ -0,0 +1,5 @@
+obj-$(CONFIG_INFINIBAND_IPOIB)          += ipoib/
+obj-$(CONFIG_INFINIBAND_SRP)            += srp/
+obj-$(CONFIG_INFINIBAND_SRPT)           += srpt/
+obj-$(CONFIG_INFINIBAND_ISER)           += iser/
+obj-$(CONFIG_INFINIBAND_ISERT)          += isert/