Re: [PATCH v3 -next 5/9] CMA: generalize CMA reserved area management functionality
Hello,
On 2014-06-16 07:40, Joonsoo Kim wrote:
Currently, there are two users on CMA functionality, one is the DMA
subsystem and the other is the KVM on powerpc. They have their own code
to manage CMA reserved area even if they looks really similar.
From my guess, it is caused by some needs on bitmap management. KVM side
wants to maintain bitmap not for 1 page, but for more size. Eventually it
use bitmap where one bit represents 64 pages.
When I implement CMA related patches, I should change those two places
to apply my change and it seem to be painful to me. I want to change
this situation and reduce future code management overhead through
this patch.
This change could also help developer who want to use CMA in their
new feature development, since they can use CMA easily without
copying pasting this reserved area management code.
In previous patches, we have prepared some features to generalize
CMA reserved area management and now it's time to do it. This patch
moves core functions to mm/cma.c and change DMA APIs to use
these functions.
There is no functional change in DMA APIs.
v2: There is no big change from v1 in mm/cma.c. Mostly renaming.
v3: remove log2.h in dma-contiguous.c (Minchan)
add some accessor functions to pass aligned base and size to
dma_contiguous_early_fixup() function
move MAX_CMA_AREAS to cma.h
I've just noticed that MAX_CMA_AREAS is used also by
arch/arm/mm/dma-mapping.c,
so we need to provide correct definition if CMA is disabled in kconfig.
I will
send a fixup patch in a few minutes.
Acked-by: Michal Nazarewicz min...@mina86.com
Acked-by: Zhang Yanfei zhangyan...@cn.fujitsu.com
Acked-by: Minchan Kim minc...@kernel.org
Reviewed-by: Aneesh Kumar K.V aneesh.ku...@linux.vnet.ibm.com
Signed-off-by: Joonsoo Kim iamjoonsoo@lge.com
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 4c88935..3116880 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -26,6 +26,7 @@
#include linux/io.h
#include linux/vmalloc.h
#include linux/sizes.h
+#include linux/cma.h
#include asm/memory.h
#include asm/highmem.h
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 00e13ce..4eac559 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -283,16 +283,6 @@ config CMA_ALIGNMENT
If unsure, leave the default value 8.
-config CMA_AREAS
- int Maximum count of the CMA device-private areas
- default 7
- help
- CMA allows to create CMA areas for particular devices. This parameter
- sets the maximum number of such device private CMA areas in the
- system.
-
- If unsure, leave the default value 7.
-
endif
endmenu
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index c6eeb2c..0411c1c 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -24,25 +24,9 @@
#include linux/memblock.h
#include linux/err.h
-#include linux/mm.h
-#include linux/mutex.h
-#include linux/page-isolation.h
#include linux/sizes.h
-#include linux/slab.h
-#include linux/swap.h
-#include linux/mm_types.h
#include linux/dma-contiguous.h
-#include linux/log2.h
-
-struct cma {
- unsigned long base_pfn;
- unsigned long count;
- unsigned long *bitmap;
- unsigned int order_per_bit; /* Order of pages represented by one bit */
- struct mutexlock;
-};
-
-struct cma *dma_contiguous_default_area;
+#include linux/cma.h
#ifdef CONFIG_CMA_SIZE_MBYTES
#define CMA_SIZE_MBYTES CONFIG_CMA_SIZE_MBYTES
@@ -50,6 +34,8 @@ struct cma *dma_contiguous_default_area;
#define CMA_SIZE_MBYTES 0
#endif
+struct cma *dma_contiguous_default_area;
+
/*
* Default global CMA area size can be defined in kernel's .config.
* This is useful mainly for distro maintainers to create a kernel
@@ -156,169 +142,6 @@ void __init dma_contiguous_reserve(phys_addr_t limit)
}
}
-static DEFINE_MUTEX(cma_mutex);
-
-static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order)
-{
- return (1 (align_order cma-order_per_bit)) - 1;
-}
-
-static unsigned long cma_bitmap_maxno(struct cma *cma)
-{
- return cma-count cma-order_per_bit;
-}
-
-static unsigned long cma_bitmap_pages_to_bits(struct cma *cma,
- unsigned long pages)
-{
- return ALIGN(pages, 1 cma-order_per_bit) cma-order_per_bit;
-}
-
-static void cma_clear_bitmap(struct cma *cma, unsigned long pfn, int count)
-{
- unsigned long bitmap_no, bitmap_count;
-
- bitmap_no = (pfn - cma-base_pfn) cma-order_per_bit;
- bitmap_count = cma_bitmap_pages_to_bits(cma, count);
-
- mutex_lock(cma-lock);
- bitmap_clear(cma-bitmap, bitmap_no, bitmap_count);
- mutex_unlock(cma-lock);
-}
-
-static int __init cma_activate_area(struct cma *cma)
-{
- int bitmap_size = BITS_TO_LONGS(cma_bitmap_maxno(cma)) * sizeof(long);
-
[PATCH v3 -next 5/9] CMA: generalize CMA reserved area management functionality
Currently, there are two users on CMA functionality, one is the DMA
subsystem and the other is the KVM on powerpc. They have their own code
to manage CMA reserved area even if they looks really similar.
From my guess, it is caused by some needs on bitmap management. KVM side
wants to maintain bitmap not for 1 page, but for more size. Eventually it
use bitmap where one bit represents 64 pages.
When I implement CMA related patches, I should change those two places
to apply my change and it seem to be painful to me. I want to change
this situation and reduce future code management overhead through
this patch.
This change could also help developer who want to use CMA in their
new feature development, since they can use CMA easily without
copying pasting this reserved area management code.
In previous patches, we have prepared some features to generalize
CMA reserved area management and now it's time to do it. This patch
moves core functions to mm/cma.c and change DMA APIs to use
these functions.
There is no functional change in DMA APIs.
v2: There is no big change from v1 in mm/cma.c. Mostly renaming.
v3: remove log2.h in dma-contiguous.c (Minchan)
add some accessor functions to pass aligned base and size to
dma_contiguous_early_fixup() function
move MAX_CMA_AREAS to cma.h
Acked-by: Michal Nazarewicz min...@mina86.com
Acked-by: Zhang Yanfei zhangyan...@cn.fujitsu.com
Acked-by: Minchan Kim minc...@kernel.org
Reviewed-by: Aneesh Kumar K.V aneesh.ku...@linux.vnet.ibm.com
Signed-off-by: Joonsoo Kim iamjoonsoo@lge.com
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 4c88935..3116880 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -26,6 +26,7 @@
#include linux/io.h
#include linux/vmalloc.h
#include linux/sizes.h
+#include linux/cma.h
#include asm/memory.h
#include asm/highmem.h
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 00e13ce..4eac559 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -283,16 +283,6 @@ config CMA_ALIGNMENT
If unsure, leave the default value 8.
-config CMA_AREAS
- int Maximum count of the CMA device-private areas
- default 7
- help
- CMA allows to create CMA areas for particular devices. This parameter
- sets the maximum number of such device private CMA areas in the
- system.
-
- If unsure, leave the default value 7.
-
endif
endmenu
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index c6eeb2c..0411c1c 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -24,25 +24,9 @@
#include linux/memblock.h
#include linux/err.h
-#include linux/mm.h
-#include linux/mutex.h
-#include linux/page-isolation.h
#include linux/sizes.h
-#include linux/slab.h
-#include linux/swap.h
-#include linux/mm_types.h
#include linux/dma-contiguous.h
-#include linux/log2.h
-
-struct cma {
- unsigned long base_pfn;
- unsigned long count;
- unsigned long *bitmap;
- unsigned int order_per_bit; /* Order of pages represented by one bit */
- struct mutexlock;
-};
-
-struct cma *dma_contiguous_default_area;
+#include linux/cma.h
#ifdef CONFIG_CMA_SIZE_MBYTES
#define CMA_SIZE_MBYTES CONFIG_CMA_SIZE_MBYTES
@@ -50,6 +34,8 @@ struct cma *dma_contiguous_default_area;
#define CMA_SIZE_MBYTES 0
#endif
+struct cma *dma_contiguous_default_area;
+
/*
* Default global CMA area size can be defined in kernel's .config.
* This is useful mainly for distro maintainers to create a kernel
@@ -156,169 +142,6 @@ void __init dma_contiguous_reserve(phys_addr_t limit)
}
}
-static DEFINE_MUTEX(cma_mutex);
-
-static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order)
-{
- return (1 (align_order cma-order_per_bit)) - 1;
-}
-
-static unsigned long cma_bitmap_maxno(struct cma *cma)
-{
- return cma-count cma-order_per_bit;
-}
-
-static unsigned long cma_bitmap_pages_to_bits(struct cma *cma,
- unsigned long pages)
-{
- return ALIGN(pages, 1 cma-order_per_bit) cma-order_per_bit;
-}
-
-static void cma_clear_bitmap(struct cma *cma, unsigned long pfn, int count)
-{
- unsigned long bitmap_no, bitmap_count;
-
- bitmap_no = (pfn - cma-base_pfn) cma-order_per_bit;
- bitmap_count = cma_bitmap_pages_to_bits(cma, count);
-
- mutex_lock(cma-lock);
- bitmap_clear(cma-bitmap, bitmap_no, bitmap_count);
- mutex_unlock(cma-lock);
-}
-
-static int __init cma_activate_area(struct cma *cma)
-{
- int bitmap_size = BITS_TO_LONGS(cma_bitmap_maxno(cma)) * sizeof(long);
- unsigned long base_pfn = cma-base_pfn, pfn = base_pfn;
- unsigned i = cma-count pageblock_order;
- struct zone *zone;
-
- cma-bitmap = kzalloc(bitmap_size, GFP_KERNEL);
-
- if (!cma-bitmap)
- return -ENOMEM;
-
-
