mm/cma: Move dma contiguous changes into a seperate config

We want to use CMA for allocating hash page table and real mode area for
PPC64. Hence move DMA contiguous related changes into a seperate config
so that ppc64 can enable CMA without requiring DMA contiguous.

Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[removed defconfig changes]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

6 files changed, 34 insertions, 22 deletions

diff --git a/arch/arm/include/asm/dma-contiguous.h b/arch/arm/include/asm/dma-contiguous.h
index 3ed37b4d93da..e072bb2ba1b1 100644
--- a/arch/arm/include/asm/dma-contiguous.h
+++ b/arch/arm/include/asm/dma-contiguous.h
@@ -2,7 +2,7 @@
 #define ASMARM_DMA_CONTIGUOUS_H
 
 #ifdef __KERNEL__
-#ifdef CONFIG_CMA
+#ifdef CONFIG_DMA_CMA
 
 #include <linux/types.h>
 #include <asm-generic/dma-contiguous.h>
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index ef3e0f3aac96..1fb40dc37ec2 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -358,7 +358,7 @@ static int __init atomic_pool_init(void)
         if (!pages)
                 goto no_pages;
 
-        if (IS_ENABLED(CONFIG_CMA))
+        if (IS_ENABLED(CONFIG_DMA_CMA))
                 ptr = __alloc_from_contiguous(NULL, pool->size, prot, &page,
                                               atomic_pool_init);
         else
@@ -670,7 +670,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
                 addr = __alloc_simple_buffer(dev, size, gfp, &page);
         else if (!(gfp & __GFP_WAIT))
                 addr = __alloc_from_pool(size, &page);
-        else if (!IS_ENABLED(CONFIG_CMA))
+        else if (!IS_ENABLED(CONFIG_DMA_CMA))
                 addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller);
         else
                 addr = __alloc_from_contiguous(dev, size, prot, &page, caller);
@@ -759,7 +759,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
                 __dma_free_buffer(page, size);
         } else if (__free_from_pool(cpu_addr, size)) {
                 return;
-        } else if (!IS_ENABLED(CONFIG_CMA)) {
+        } else if (!IS_ENABLED(CONFIG_DMA_CMA)) {
                 __dma_free_remap(cpu_addr, size);
                 __dma_free_buffer(page, size);
         } else {
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 07abd9d76f7f..10cd80af2aec 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -202,11 +202,9 @@ config DMA_SHARED_BUFFER
           APIs extension; the file's descriptor can then be passed on to other
           driver.
 
-config CMA
-        bool "Contiguous Memory Allocator"
-        depends on HAVE_DMA_CONTIGUOUS && HAVE_MEMBLOCK
-        select MIGRATION
-        select MEMORY_ISOLATION
+config DMA_CMA
+        bool "DMA Contiguous Memory Allocator"
+        depends on HAVE_DMA_CONTIGUOUS && CMA
         help
           This enables the Contiguous Memory Allocator which allows drivers
           to allocate big physically-contiguous blocks of memory for use with
@@ -215,17 +213,7 @@ config CMA
           For more information see <include/linux/dma-contiguous.h>.
           If unsure, say "n".
 
-if CMA
-
-config CMA_DEBUG
-        bool "CMA debug messages (DEVELOPMENT)"
-        depends on DEBUG_KERNEL
-        help
-          Turns on debug messages in CMA.  This produces KERN_DEBUG
-          messages for every CMA call as well as various messages while
-          processing calls such as dma_alloc_from_contiguous().
-          This option does not affect warning and error messages.
-
+if  DMA_CMA
 comment "Default contiguous memory area size:"
 
 config CMA_SIZE_MBYTES
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index 4e22ce3ed73d..5d93bb519753 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -6,7 +6,7 @@ obj-y			:= core.o bus.o dd.o syscore.o \
                            attribute_container.o transport_class.o \
                            topology.o
 obj-$(CONFIG_DEVTMPFS)  += devtmpfs.o
-obj-$(CONFIG_CMA) += dma-contiguous.o
+obj-$(CONFIG_DMA_CMA) += dma-contiguous.o
 obj-y                   += power/
 obj-$(CONFIG_HAS_DMA)   += dma-mapping.o
 obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o
diff --git a/include/linux/dma-contiguous.h b/include/linux/dma-contiguous.h
index 01b5c84be828..00141d3325fe 100644
--- a/include/linux/dma-contiguous.h
+++ b/include/linux/dma-contiguous.h
@@ -57,7 +57,7 @@ struct cma;
 struct page;
 struct device;
 
-#ifdef CONFIG_CMA
+#ifdef CONFIG_DMA_CMA
 
 /*
  * There is always at least global CMA area and a few optional device
diff --git a/mm/Kconfig b/mm/Kconfig
index e742d06285b7..26a5f815cfc3 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -477,3 +477,27 @@ config FRONTSWAP
           and swap data is stored as normal on the matching swap device.
 
           If unsure, say Y to enable frontswap.
+
+config CMA
+        bool "Contiguous Memory Allocator"
+        depends on HAVE_MEMBLOCK
+        select MIGRATION
+        select MEMORY_ISOLATION
+        help
+          This enables the Contiguous Memory Allocator which allows other
+          subsystems to allocate big physically-contiguous blocks of memory.
+          CMA reserves a region of memory and allows only movable pages to
+          be allocated from it. This way, the kernel can use the memory for
+          pagecache and when a subsystem requests for contiguous area, the
+          allocated pages are migrated away to serve the contiguous request.
+
+          If unsure, say "n".
+
+config CMA_DEBUG
+        bool "CMA debug messages (DEVELOPMENT)"
+        depends on DEBUG_KERNEL && CMA
+        help
+          Turns on debug messages in CMA.  This produces KERN_DEBUG
+          messages for every CMA call as well as various messages while
+          processing calls such as dma_alloc_from_contiguous().
+          This option does not affect warning and error messages.