This allows some drivers compile on arches that don't support DMA
(e.g. s390).
Signed-off-by: John W. Linville <[email protected]>
---
Is there any reason why this header should not cover the whole DMA API?
Compile-tested only...
include/asm-generic/dma-mapping-broken.h | 134 ++++++++++++++++++++++++++++++
1 files changed, 134 insertions(+), 0 deletions(-)
diff --git a/include/asm-generic/dma-mapping-broken.h b/include/asm-generic/dma-mapping-broken.h
index 29413d3..84812dd 100644
--- a/include/asm-generic/dma-mapping-broken.h
+++ b/include/asm-generic/dma-mapping-broken.h
@@ -21,4 +21,116 @@ dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
+static inline dma_addr_t
+dma_map_single(struct device *dev, void *ptr, size_t size,
+ enum dma_data_direction direction)
+{
+ BUG();
+ return (dma_addr_t)0;
+}
+
+static inline void
+dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
+ enum dma_data_direction direction)
+{
+ BUG();
+}
+
+static inline int
+dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+ enum dma_data_direction direction)
+{
+ BUG();
+ return 0;
+}
+
+static inline void
+dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
+ enum dma_data_direction direction)
+{
+ BUG();
+}
+
+static inline dma_addr_t
+dma_map_page(struct device *dev, struct page *page, unsigned long offset,
+ size_t size, enum dma_data_direction direction)
+{
+ BUG();
+ return (dma_addr_t)0;
+}
+
+static inline void
+dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
+ enum dma_data_direction direction)
+{
+ BUG();
+}
+
+static inline void
+dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size,
+ enum dma_data_direction direction)
+{
+ BUG();
+}
+
+static inline void
+dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
+ unsigned long offset, size_t size,
+ enum dma_data_direction direction)
+{
+ BUG();
+}
+
+static inline void
+dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
+ enum dma_data_direction direction)
+{
+ BUG();
+}
+
+#define dma_sync_single_for_device dma_sync_single_for_cpu
+#define dma_sync_single_range_for_device dma_sync_single_range_for_cpu
+#define dma_sync_sg_for_device dma_sync_sg_for_cpu
+
+static inline int
+dma_mapping_error(dma_addr_t dma_addr)
+{
+ BUG();
+ return 1;
+}
+
+static inline int
+dma_supported(struct device *dev, u64 mask)
+{
+ return 0;
+}
+
+static inline int
+dma_set_mask(struct device *dev, u64 mask)
+{
+ BUG();
+ return -EIO;
+}
+
+static inline int
+dma_get_cache_alignment(void)
+{
+ BUG();
+ return 0;
+}
+
+int
+dma_is_consistent(struct device *dev, dma_addr_t dma_handle)
+{
+ BUG();
+ return 0;
+}
+
+static inline void
+dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+ enum dma_data_direction direction)
+{
+ BUG();
+}
+
#endif /* _ASM_GENERIC_DMA_MAPPING_H */
--
1.4.4.2
On Thu, Feb 22, 2007 at 07:59:45PM -0500, John W. Linville wrote:
> This allows some drivers compile on arches that don't support DMA
> (e.g. s390).
Which drivers are we talking about? Last time I checked an allmodconfig
just compiled.
I'd rather like to the opposite: rip out everything that depends on DMA
(via e.g. CONFIG_HAS_DMA), so we don't have to compile in all the unused
code. If that is is possible...
--
Heiko Carstens
Linux on System z Development
IBM Deutschland Entwicklung GmbH
Vorsitzender des Aufsichtsrats: Johann Weihen
Geschaeftsfuehrung : Herbert Kircher
Sitz der Gesellschaft: Boeblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294
How about this for telling that an architecture doesn't support DMA?
At least we could get rid of dma-mapping-broken.h and don't need to
compile some afterwards dead code.
Signed-off-by: Heiko Carstens <[email protected]>
---
arch/s390/Kconfig | 3 +++
drivers/base/Makefile | 4 ++--
include/asm-s390/dma-mapping.h | 2 --
lib/Kconfig | 5 +++++
4 files changed, 10 insertions(+), 4 deletions(-)
Index: linux-2.6/arch/s390/Kconfig
===================================================================
--- linux-2.6.orig/arch/s390/Kconfig
+++ linux-2.6/arch/s390/Kconfig
@@ -44,6 +44,9 @@ config GENERIC_TIME
config NO_IOMEM
def_bool y
+config NO_DMA
+ def_bool y
+
mainmenu "Linux Kernel Configuration"
config S390
Index: linux-2.6/drivers/base/Makefile
===================================================================
--- linux-2.6.orig/drivers/base/Makefile
+++ linux-2.6/drivers/base/Makefile
@@ -2,10 +2,10 @@
obj-y := core.o sys.o bus.o dd.o \
driver.o class.o platform.o \
- cpu.o firmware.o init.o map.o dmapool.o \
- dma-mapping.o devres.o \
+ cpu.o firmware.o init.o map.o devres.o \
attribute_container.o transport_class.o
obj-y += power/
+obj-$(CONFIG_DMA) += dma-mapping.o dmapool.o
obj-$(CONFIG_ISA) += isa.o
obj-$(CONFIG_FW_LOADER) += firmware_class.o
obj-$(CONFIG_NUMA) += node.o
Index: linux-2.6/include/asm-s390/dma-mapping.h
===================================================================
--- linux-2.6.orig/include/asm-s390/dma-mapping.h
+++ linux-2.6/include/asm-s390/dma-mapping.h
@@ -9,6 +9,4 @@
#ifndef _ASM_DMA_MAPPING_H
#define _ASM_DMA_MAPPING_H
-#include <asm-generic/dma-mapping-broken.h>
-
#endif /* _ASM_DMA_MAPPING_H */
Index: linux-2.6/lib/Kconfig
===================================================================
--- linux-2.6.orig/lib/Kconfig
+++ linux-2.6/lib/Kconfig
@@ -111,4 +111,9 @@ config HAS_IOPORT
depends on HAS_IOMEM && !NO_IOPORT
default y
+config HAS_DMA
+ boolean
+ depends on !NO_DMA
+ default y
+
endmenu
--
Heiko Carstens
Linux on System z Development
IBM Deutschland Entwicklung GmbH
Vorsitzender des Aufsichtsrats: Johann Weihen
Geschaeftsfuehrung : Herbert Kircher
Sitz der Gesellschaft: Boeblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294
On Fri, Feb 23, 2007 at 07:13:32AM +0100, Heiko Carstens wrote:
> How about this for telling that an architecture doesn't support DMA?
> At least we could get rid of dma-mapping-broken.h and don't need to
> compile some afterwards dead code.
>
> Signed-off-by: Heiko Carstens <[email protected]>
> ---
> arch/s390/Kconfig | 3 +++
> drivers/base/Makefile | 4 ++--
> include/asm-s390/dma-mapping.h | 2 --
> lib/Kconfig | 5 +++++
> 4 files changed, 10 insertions(+), 4 deletions(-)
>
> Index: linux-2.6/arch/s390/Kconfig
> ===================================================================
> --- linux-2.6.orig/arch/s390/Kconfig
> +++ linux-2.6/arch/s390/Kconfig
> @@ -44,6 +44,9 @@ config GENERIC_TIME
> config NO_IOMEM
> def_bool y
>
> +config NO_DMA
> + def_bool y
> +
> mainmenu "Linux Kernel Configuration"
>
> config S390
> Index: linux-2.6/drivers/base/Makefile
> ===================================================================
> --- linux-2.6.orig/drivers/base/Makefile
> +++ linux-2.6/drivers/base/Makefile
> @@ -2,10 +2,10 @@
>
> obj-y := core.o sys.o bus.o dd.o \
> driver.o class.o platform.o \
> - cpu.o firmware.o init.o map.o dmapool.o \
> - dma-mapping.o devres.o \
> + cpu.o firmware.o init.o map.o devres.o \
> attribute_container.o transport_class.o
> obj-y += power/
> +obj-$(CONFIG_DMA) += dma-mapping.o dmapool.o
This should have been CONFIG_HAS_DMA. Anyway I'm going to resend this one
if nobody objects.
> obj-$(CONFIG_ISA) += isa.o
> obj-$(CONFIG_FW_LOADER) += firmware_class.o
> obj-$(CONFIG_NUMA) += node.o
> Index: linux-2.6/include/asm-s390/dma-mapping.h
> ===================================================================
> --- linux-2.6.orig/include/asm-s390/dma-mapping.h
> +++ linux-2.6/include/asm-s390/dma-mapping.h
> @@ -9,6 +9,4 @@
> #ifndef _ASM_DMA_MAPPING_H
> #define _ASM_DMA_MAPPING_H
>
> -#include <asm-generic/dma-mapping-broken.h>
> -
> #endif /* _ASM_DMA_MAPPING_H */
> Index: linux-2.6/lib/Kconfig
> ===================================================================
> --- linux-2.6.orig/lib/Kconfig
> +++ linux-2.6/lib/Kconfig
> @@ -111,4 +111,9 @@ config HAS_IOPORT
> depends on HAS_IOMEM && !NO_IOPORT
> default y
>
> +config HAS_DMA
> + boolean
> + depends on !NO_DMA
> + default y
> +
> endmenu
--
Heiko Carstens
Linux on System z Development
IBM Deutschland Entwicklung GmbH
Vorsitzender des Aufsichtsrats: Johann Weihen
Geschaeftsfuehrung : Herbert Kircher
Sitz der Gesellschaft: Boeblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294
On Fri, Feb 23, 2007 at 07:13:32AM +0100, Heiko Carstens wrote:
> How about this for telling that an architecture doesn't support DMA?
> At least we could get rid of dma-mapping-broken.h and don't need to
> compile some afterwards dead code.
>
> Signed-off-by: Heiko Carstens <[email protected]>
This like a lot better of an idea than stubbing out things which should never
be built in the first place...
Cheers,
Kyle
On Fri, Feb 23, 2007 at 08:57:41AM -0500, Kyle McMartin wrote:
> On Fri, Feb 23, 2007 at 07:13:32AM +0100, Heiko Carstens wrote:
> > How about this for telling that an architecture doesn't support DMA?
> > At least we could get rid of dma-mapping-broken.h and don't need to
> > compile some afterwards dead code.
> >
> > Signed-off-by: Heiko Carstens <[email protected]>
>
> This like a lot better of an idea than stubbing out things which should never
> be built in the first place...
My only thought was that the intent must have been to allow compilation of a driver
that checks for DMA at runtime (via dma_supported). But, I guess dma_supported is intended
as a platform-level check?
If the DMA availability is at the arch level then such a driver could
use (albeit ugly) compile flags to cover that situation...?
Well, either way is fine with me.
John
--
John W. Linville
[email protected]
From: Heiko Carstens <[email protected]>
Architectures that don't support DMA can say so by adding a
config NO_DMA to their Kconfig file. This will prevent compilation
of some dma specific driver code. Also dma-mapping-broken.h isn't
needed anymore on at least s390.
This avoids compilation and linking of otherwise dead/broken code.
Signed-off-by: Heiko Carstens <[email protected]>
---
Other architectures that include dma-mapping-broken.h are
arm26, h8300, m68k, m68knommu and v850. If these could be converted
as well we could get rid of the header file.
arch/s390/Kconfig | 3 +++
drivers/base/Makefile | 4 ++--
include/asm-s390/dma-mapping.h | 2 --
lib/Kconfig | 5 +++++
4 files changed, 10 insertions(+), 4 deletions(-)
Index: linux-2.6/arch/s390/Kconfig
===================================================================
--- linux-2.6.orig/arch/s390/Kconfig
+++ linux-2.6/arch/s390/Kconfig
@@ -44,6 +44,9 @@ config GENERIC_TIME
config NO_IOMEM
def_bool y
+config NO_DMA
+ def_bool y
+
mainmenu "Linux Kernel Configuration"
config S390
Index: linux-2.6/drivers/base/Makefile
===================================================================
--- linux-2.6.orig/drivers/base/Makefile
+++ linux-2.6/drivers/base/Makefile
@@ -2,10 +2,10 @@
obj-y := core.o sys.o bus.o dd.o \
driver.o class.o platform.o \
- cpu.o firmware.o init.o map.o dmapool.o \
- dma-mapping.o devres.o \
+ cpu.o firmware.o init.o map.o devres.o \
attribute_container.o transport_class.o
obj-y += power/
+obj-$(CONFIG_HAS_DMA) += dma-mapping.o dmapool.o
obj-$(CONFIG_ISA) += isa.o
obj-$(CONFIG_FW_LOADER) += firmware_class.o
obj-$(CONFIG_NUMA) += node.o
Index: linux-2.6/include/asm-s390/dma-mapping.h
===================================================================
--- linux-2.6.orig/include/asm-s390/dma-mapping.h
+++ linux-2.6/include/asm-s390/dma-mapping.h
@@ -9,6 +9,4 @@
#ifndef _ASM_DMA_MAPPING_H
#define _ASM_DMA_MAPPING_H
-#include <asm-generic/dma-mapping-broken.h>
-
#endif /* _ASM_DMA_MAPPING_H */
Index: linux-2.6/lib/Kconfig
===================================================================
--- linux-2.6.orig/lib/Kconfig
+++ linux-2.6/lib/Kconfig
@@ -111,4 +111,9 @@ config HAS_IOPORT
depends on HAS_IOMEM && !NO_IOPORT
default y
+config HAS_DMA
+ boolean
+ depends on !NO_DMA
+ default y
+
endmenu
--
Heiko Carstens
Linux on System z Development
IBM Deutschland Entwicklung GmbH
Vorsitzender des Aufsichtsrats: Johann Weihen
Geschaeftsfuehrung : Herbert Kircher
Sitz der Gesellschaft: Boeblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294
[ apologies for reviving an old conversation ]
On 2/26/07, Heiko Carstens <[email protected]> wrote:
> From: Heiko Carstens <[email protected]>
>
> Architectures that don't support DMA can say so by adding a
> config NO_DMA to their Kconfig file. This will prevent compilation
> of some dma specific driver code. Also dma-mapping-broken.h isn't
> needed anymore on at least s390.
> This avoids compilation and linking of otherwise dead/broken code.
>
I went back and read the thread leading up to this patch and I am of
the opinion that John's approach (adding more stubs to
dma-mapping-broken.h:
http://marc.info/?l=linux-kernel&m=117219377712232&w=2) is needed in
_addition_ to this Kconfig option. In my particular case I have an
API with a DMA and a non-DMA path written in such a way that the DMA
path can be compiled away. Without dma-mapping-broken.h support the
API is unnecessarily forced to violate point 2 of
Documentation/SubmittingPatches (#ifdefs are ugly).
In other words let CONFIG_HAS_DMA prevent pure DMA code from being
built, but do not preclude "clever" implementations from calling
broken code.
If there are no objections I plan to resubmit John's changes with the
addition below, which allows CONFIG_HAS_DMA=n architectures to delete
their respective dma-mapping.h file.
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 9a663c6..2dc21cb 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -31,7 +31,11 @@ static inline int valid_dma_direction(int dma_direction)
(dma_direction == DMA_FROM_DEVICE));
}
+#ifdef CONFIG_HAS_DMA
#include <asm/dma-mapping.h>
+#else
+#include <asm-generic/dma-mapping-broken.h>
+#endif
/* Backwards compat, remove in 2.7.x */
#define dma_sync_single dma_sync_single_for_cpu
On Fri, 25 May 2007 09:36:31 -0700,
"Dan Williams" <[email protected]> wrote:
> I went back and read the thread leading up to this patch and I am of
> the opinion that John's approach (adding more stubs to
> dma-mapping-broken.h:
> http://marc.info/?l=linux-kernel&m=117219377712232&w=2) is needed in
> _addition_ to this Kconfig option. In my particular case I have an
> API with a DMA and a non-DMA path written in such a way that the DMA
> path can be compiled away. Without dma-mapping-broken.h support the
> API is unnecessarily forced to violate point 2 of
> Documentation/SubmittingPatches (#ifdefs are ugly).
IMO, well-placed #ifdefs are preferrable to dragging non-working code
around. Like:
- put the DMA path in a file only build for MY_STUFF_USE_DMA
- let MY_STUFF select MY_STUFF_USE_DMA if HAS_DMA
- have a header file that points to the implementation for
MY_STUFF_USE_DMA and uses well defined stubs for !MY_STUFF_USE_DMA,
like returning ICannotDoThat for check_if_can_do() (kind of like what
include/linux/sysfs.h does, for example)
This contains the #ifdefs in a header, doesn't compile stuff that won't
work anyway on !HAS_DMA, and adds the ability to disable
MY_STUFF_USE_DMA even if HAS_DMA at a later time if someone wants it.
> In other words let CONFIG_HAS_DMA prevent pure DMA code from being
> built, but do not preclude "clever" implementations from calling
> broken code.
If it calls broken code, it may not be so "clever" after all :)
What I don't like about this is
- compiles stuff that is not needed on !HAS_DMA
- worse, compiles stuff that will not work on !HAS_DMA
- does not encourage to split code properly into a DMA and a non-DMA
part
[ please let me know if you want to be dropped from the cc ]
> From: Cornelia Huck [mailto:[email protected]]
> IMO, well-placed #ifdefs are preferrable to dragging non-working code
> around. Like:
>
> - put the DMA path in a file only build for MY_STUFF_USE_DMA
> - let MY_STUFF select MY_STUFF_USE_DMA if HAS_DMA
> - have a header file that points to the implementation for
> MY_STUFF_USE_DMA and uses well defined stubs for !MY_STUFF_USE_DMA,
> like returning ICannotDoThat for check_if_can_do() (kind of like
what
> include/linux/sysfs.h does, for example)
>
> This contains the #ifdefs in a header, doesn't compile stuff that
won't
> work anyway on !HAS_DMA, and adds the ability to disable
> MY_STUFF_USE_DMA even if HAS_DMA at a later time if someone wants it.
>
> > In other words let CONFIG_HAS_DMA prevent pure DMA code from being
> > built, but do not preclude "clever" implementations from calling
> > broken code.
>
> If it calls broken code, it may not be so "clever" after all :)
>
Yes, at run time, but not necessarily at compile time.
> What I don't like about this is
>
> - compiles stuff that is not needed on !HAS_DMA
> - worse, compiles stuff that will not work on !HAS_DMA
> - does not encourage to split code properly into a DMA and a non-DMA
> part
I came to the same conclusions as I started to implement the bug-stubs.
The patch (to follow) attempts to satisfy all the concerns you outline
as well as my observation that async_tx requires no factoring for the
!HAS_DMA case.
With the patch non-dma-architectures that try to build code with true
dependencies on the DMA api will fail to link i.e.:
CONFIG_DMA_ENGINE=y CONFIG_HAS_DMA=n ASYNC_MEMCPY=y
CC init/version.o
LD init/built-in.o
LD .tmp_vmlinux1
async_tx/built-in.o: In function `async_memcpy':
xor.c:(.text+0x770): undefined reference to `dma_map_page'
xor.c:(.text+0x798): undefined reference to `dma_map_page'
xor.c:(.text+0x968): undefined reference to `dma_map_page'
Now changing CONFIG_DMA_ENGINE to depend on HAS_DMA (which is more
correct than saying !S390). Results in:
CONFIG_DMA_ENGINE=n CONFIG_HAS_DMA=n ASYNC_MEMCPY=y
CC init/version.o
LD init/built-in.o
LD .tmp_vmlinux1
KSYM .tmp_kallsyms1.S
AS .tmp_kallsyms1.o
LD .tmp_vmlinux2
KSYM .tmp_kallsyms2.S
AS .tmp_kallsyms2.o
LD vmlinux
This also allows include/asm-s390/dma-mapping.h to be dropped.
Dan
Continuing the work started in 411f0f3edc141a582190d3605cadd1d993abb6df ...
This enables code with a dma path, that compiles away, to build without
requiring additional code factoring. It also prevents code that calls
dma_alloc_coherent and dma_free_coherent from linking whereas previously
the code would hit a BUG() at run time. Finally, it allows archs that set
!HAS_DMA to delete their asm/dma-mapping.h file.
Cc: Cornelia Huck <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: John W. Linville <[email protected]>
Cc: Kyle McMartin <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Jeff Garzik <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Signed-off-by: Dan Williams <[email protected]>
---
arch/arm26/Kconfig | 3 +
arch/h8300/Kconfig | 3 +
arch/m32r/Kconfig | 3 +
drivers/dma/Kconfig | 2 -
include/asm-arm26/dma-mapping.h | 2 -
include/asm-generic/dma-mapping-broken.h | 82 ++++++++++++++++++++++++++----
include/asm-h8300/dma-mapping.h | 1
include/asm-m32r/dma-mapping.h | 6 --
include/asm-s390/dma-mapping.h | 12 ----
include/linux/dma-mapping.h | 4 +
10 files changed, 84 insertions(+), 34 deletions(-)
diff --git a/arch/arm26/Kconfig b/arch/arm26/Kconfig
index 20688bc..9044f33 100644
--- a/arch/arm26/Kconfig
+++ b/arch/arm26/Kconfig
@@ -17,6 +17,9 @@ config MMU
bool
default y
+config NO_DMA
+ def_bool y
+
config ARCH_ACORN
bool
default y
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 618dbad..e35f74e 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -68,6 +68,9 @@ config TIME_LOW_RES
config NO_IOPORT
def_bool y
+config NO_DMA
+ def_bool y
+
config ISA
bool
default y
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index c3bb8a7..8ccf3e4 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -31,6 +31,9 @@ config GENERIC_IRQ_PROBE
config NO_IOPORT
def_bool y
+config NO_DMA
+ def_bool y
+
source "init/Kconfig"
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 72be6c6..59305bc 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -3,7 +3,7 @@
#
menu "DMA Engine support"
- depends on !S390
+ depends on HAS_DMA
config DMA_ENGINE
bool "Support for DMA engines"
diff --git a/include/asm-arm26/dma-mapping.h b/include/asm-arm26/dma-mapping.h
deleted file mode 100644
index a95eae0..0000000
--- a/include/asm-arm26/dma-mapping.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#include <asm-generic/dma-mapping-broken.h>
-
diff --git a/include/asm-generic/dma-mapping-broken.h b/include/asm-generic/dma-mapping-broken.h
index 29413d3..e2468f8 100644
--- a/include/asm-generic/dma-mapping-broken.h
+++ b/include/asm-generic/dma-mapping-broken.h
@@ -1,24 +1,82 @@
#ifndef _ASM_GENERIC_DMA_MAPPING_H
#define _ASM_GENERIC_DMA_MAPPING_H
-/* This is used for archs that do not support DMA */
+/* define the dma api to allow compilation but not linking of
+ * dma dependent code. Code that depends on the dma-mapping
+ * API needs to set 'depends on HAS_DMA' in its Kconfig
+ */
-static inline void *
+struct scatterlist;
+
+extern void *
dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
- gfp_t flag)
-{
- BUG();
- return NULL;
-}
+ gfp_t flag);
-static inline void
+extern void
dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
- dma_addr_t dma_handle)
-{
- BUG();
-}
+ dma_addr_t dma_handle);
#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
+extern dma_addr_t
+dma_map_single(struct device *dev, void *ptr, size_t size,
+ enum dma_data_direction direction);
+
+extern void
+dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
+ enum dma_data_direction direction);
+
+extern int
+dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+ enum dma_data_direction direction);
+
+extern void
+dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
+ enum dma_data_direction direction);
+
+extern dma_addr_t
+dma_map_page(struct device *dev, struct page *page, unsigned long offset,
+ size_t size, enum dma_data_direction direction);
+
+extern void
+dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
+ enum dma_data_direction direction);
+
+extern void
+dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size,
+ enum dma_data_direction direction);
+
+extern void
+dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
+ unsigned long offset, size_t size,
+ enum dma_data_direction direction);
+
+extern void
+dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
+ enum dma_data_direction direction);
+
+#define dma_sync_single_for_device dma_sync_single_for_cpu
+#define dma_sync_single_range_for_device dma_sync_single_range_for_cpu
+#define dma_sync_sg_for_device dma_sync_sg_for_cpu
+
+extern int
+dma_mapping_error(dma_addr_t dma_addr);
+
+extern int
+dma_supported(struct device *dev, u64 mask);
+
+extern int
+dma_set_mask(struct device *dev, u64 mask);
+
+extern int
+dma_get_cache_alignment(void);
+
+extern int
+dma_is_consistent(struct device *dev, dma_addr_t dma_handle);
+
+extern void
+dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+ enum dma_data_direction direction);
+
#endif /* _ASM_GENERIC_DMA_MAPPING_H */
diff --git a/include/asm-h8300/dma-mapping.h b/include/asm-h8300/dma-mapping.h
deleted file mode 100644
index d00e400..0000000
--- a/include/asm-h8300/dma-mapping.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <asm-generic/dma-mapping-broken.h>
diff --git a/include/asm-m32r/dma-mapping.h b/include/asm-m32r/dma-mapping.h
deleted file mode 100644
index f9b58eb..0000000
--- a/include/asm-m32r/dma-mapping.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef _ASM_M32R_DMA_MAPPING_H
-#define _ASM_M32R_DMA_MAPPING_H
-
-#include <asm-generic/dma-mapping-broken.h>
-
-#endif /* _ASM_M32R_DMA_MAPPING_H */
diff --git a/include/asm-s390/dma-mapping.h b/include/asm-s390/dma-mapping.h
deleted file mode 100644
index 3f8c12f..0000000
--- a/include/asm-s390/dma-mapping.h
+++ /dev/null
@@ -1,12 +0,0 @@
-/*
- * include/asm-s390/dma-mapping.h
- *
- * S390 version
- *
- * This file exists so that #include <dma-mapping.h> doesn't break anything.
- */
-
-#ifndef _ASM_DMA_MAPPING_H
-#define _ASM_DMA_MAPPING_H
-
-#endif /* _ASM_DMA_MAPPING_H */
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 9a663c6..2dc21cb 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -31,7 +31,11 @@ static inline int valid_dma_direction(int dma_direction)
(dma_direction == DMA_FROM_DEVICE));
}
+#ifdef CONFIG_HAS_DMA
#include <asm/dma-mapping.h>
+#else
+#include <asm-generic/dma-mapping-broken.h>
+#endif
/* Backwards compat, remove in 2.7.x */
#define dma_sync_single dma_sync_single_for_cpu
On Wed, 30 May 2007 14:40:02 -0700,
"Williams, Dan J" <[email protected]> wrote:
> With the patch non-dma-architectures that try to build code with true
> dependencies on the DMA api will fail to link i.e.:
>
> CONFIG_DMA_ENGINE=y CONFIG_HAS_DMA=n ASYNC_MEMCPY=y
> CC init/version.o
> LD init/built-in.o
> LD .tmp_vmlinux1
> async_tx/built-in.o: In function `async_memcpy':
> xor.c:(.text+0x770): undefined reference to `dma_map_page'
> xor.c:(.text+0x798): undefined reference to `dma_map_page'
> xor.c:(.text+0x968): undefined reference to `dma_map_page'
>
> Now changing CONFIG_DMA_ENGINE to depend on HAS_DMA (which is more
> correct than saying !S390).
Makes sense.
> Results in:
> CONFIG_DMA_ENGINE=n CONFIG_HAS_DMA=n ASYNC_MEMCPY=y
> CC init/version.o
> LD init/built-in.o
> LD .tmp_vmlinux1
> KSYM .tmp_kallsyms1.S
> AS .tmp_kallsyms1.o
> LD .tmp_vmlinux2
> KSYM .tmp_kallsyms2.S
> AS .tmp_kallsyms2.o
> LD vmlinux
>
> This also allows include/asm-s390/dma-mapping.h to be dropped.
Cool. Thanks for looking into that.