s390: add cma support

In order to make the cma infrastructure usable we need to add a small
architecture backend which calls dma_contiguous_reserve.
Otherwise we would end up with the cma allocator enabled, but no pool
where memory can be allocated from.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

3 files changed, 4 insertions, 2 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index a159dfc27b76..2d05efa31df3 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -136,6 +136,7 @@ config S390
         select HAVE_CMPXCHG_LOCAL
         select HAVE_DEBUG_KMEMLEAK
         select HAVE_DMA_API_DEBUG
+        select HAVE_DMA_CONTIGUOUS
         select HAVE_DYNAMIC_FTRACE
         select HAVE_DYNAMIC_FTRACE_WITH_REGS
         select HAVE_EFFICIENT_UNALIGNED_ACCESS
diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild
index 20f196b82a6e..24cb7452bbe7 100644
--- a/arch/s390/include/asm/Kbuild
+++ b/arch/s390/include/asm/Kbuild
@@ -1,6 +1,5 @@
-
-
 generic-y += clkdev.h
+generic-y += dma-contiguous.h
 generic-y += export.h
 generic-y += irq_work.h
 generic-y += mcs_spinlock.h
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index b75da681d4c5..17160fb43777 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -35,6 +35,7 @@
 #include <linux/root_dev.h>
 #include <linux/console.h>
 #include <linux/kernel_stat.h>
+#include <linux/dma-contiguous.h>
 #include <linux/device.h>
 #include <linux/notifier.h>
 #include <linux/pfn.h>
@@ -903,6 +904,7 @@ void __init setup_arch(char **cmdline_p)
 
         setup_memory_end();
         setup_memory();
+        dma_contiguous_reserve(memory_end);
 
         check_initrd();
         reserve_crashkernel();