c6x: dma-mapping: support debug_dma_mapping_error

Add support for debug_dma_mapping_error() call to avoid warning from debug_dma_unmap() interface when it checks for mapping error checked status. Without this patch, device driver failed to check map error warning is generated.

Signed-off-by Shuah Khan <[email protected]>

---
 arch/c6x/include/asm/dma-mapping.h |    1 +
 1 file changed, 1 insertion(+)

arch/c6x/include/asm/dma-mapping.h +1 -0

index 03579fd..3c69406 100644
@@ -32,6 +32,7 @@ static inline int dma_set_mask(struct device *dev, u64 dma_mask)
  */
 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
+	debug_dma_mapping_error(dev, dma_addr);
 	return dma_addr == ~0;
 }
 

Quoted 5 lines · Shuah Khan

Add support for debug_dma_mapping_error() call to avoid warning from debug_dma_unmap() interface when it checks for mapping error checked status. Without this patch, device driver failed to check map error warning is generated.

Quoted 4 lines

Signed-off-by Shuah Khan <[email protected]>

---
 arch/c6x/include/asm/dma-mapping.h |    1 +
 1 file changed, 1 insertion(+)

Would you like to this patch go through c6x arch tree or linux-next? Please let me know your preference.

Quoted 6 lines · Shuah Khan

Quoted 5 lines · Shuah Khan

Add support for debug_dma_mapping_error() call to avoid warning from debug_dma_unmap() interface when it checks for mapping error checked status. Without this patch, device driver failed to check map error warning is generated.

Quoted 7 lines

Quoted 4 lines

Signed-off-by Shuah Khan <[email protected]>

---
 arch/c6x/include/asm/dma-mapping.h |    1 +
 1 file changed, 1 insertion(+)

Would you like to this patch go through c6x arch tree or linux-next? Please let me know your preference.

I tried to test this but I get a build error with CONFIG_DMA_API_DEBUG:

/linux-next/lib/dma-debug.c: In function 'has_mapping_error':
/linux-next/lib/dma-debug.c:863:15: error: implicit declaration of function 'get_dma_ops' [-Werror=implicit-function-declaration] /linux-next/lib/dma-debug.c:863:34: warning: initialization makes pointer from integer without a cast [enabled by default]

C6X (along with some other architectures) doesn't have a get_dma_ops() function defined.

Quoted 21 lines · Mark Salter

Quoted 6 lines · Shuah Khan

Quoted 5 lines · Shuah Khan

Add support for debug_dma_mapping_error() call to avoid warning from debug_dma_unmap() interface when it checks for mapping error checked status. Without this patch, device driver failed to check map error warning is generated.

Quoted 7 lines

Quoted 4 lines

Signed-off-by Shuah Khan <[email protected]>

---
 arch/c6x/include/asm/dma-mapping.h |    1 +
 1 file changed, 1 insertion(+)

Would you like to this patch go through c6x arch tree or linux-next? Please let me know your preference.

I tried to test this but I get a build error with CONFIG_DMA_API_DEBUG:

/linux-next/lib/dma-debug.c: In function 'has_mapping_error':
/linux-next/lib/dma-debug.c:863:15: error: implicit declaration of function 'get_dma_ops' [-Werror=implicit-function-declaration] /linux-next/lib/dma-debug.c:863:34: warning: initialization makes pointer from integer without a cast [enabled by default]

Quoted 2 lines

C6X (along with some other architectures) doesn't have a get_dma_ops() function defined.

That is a problem I didn't think about. I did a check and looks like c6x and frv are the only ones that don't have get_dma_ops() defined. frv is

in a different category as it doesn't use dma_debug interfaces. IN the case c6x, now with my change to add debug_dma_mapping_error(), we will start seeing warnings since dma_map_page() and dma_map_single() are debugged with a call to debug_dma_map_page() and the corresponding dma_mapping_error() interface doesn't call debug_dma_mapping_error() interface

- Does adding get_dma_ops() make sense? Doesn't look like c6x exports dma_ops?

Any other ideas?

Quoted 22 lines · Shuah Khan

Quoted 21 lines · Mark Salter

Quoted 6 lines · Shuah Khan

Quoted 5 lines · Shuah Khan

Add support for debug_dma_mapping_error() call to avoid warning from debug_dma_unmap() interface when it checks for mapping error checked status. Without this patch, device driver failed to check map error warning is generated.

Quoted 7 lines

Quoted 4 lines

Signed-off-by Shuah Khan <[email protected]>

---
 arch/c6x/include/asm/dma-mapping.h |    1 +
 1 file changed, 1 insertion(+)

Would you like to this patch go through c6x arch tree or linux-next? Please let me know your preference.

I tried to test this but I get a build error with CONFIG_DMA_API_DEBUG:

/linux-next/lib/dma-debug.c: In function 'has_mapping_error':
/linux-next/lib/dma-debug.c:863:15: error: implicit declaration of function 'get_dma_ops' [-Werror=implicit-function-declaration] /linux-next/lib/dma-debug.c:863:34: warning: initialization makes pointer from integer without a cast [enabled by default]

Quoted 5 lines

Quoted 2 lines

C6X (along with some other architectures) doesn't have a get_dma_ops() function defined.

That is a problem I didn't think about. I did a check and looks like c6x and frv are the only ones that don't have get_dma_ops() defined. frv is

By my count, there are 14 architectures with get_dma_ops() and 14 without.

Quoted 7 lines

in a different category as it doesn't use dma_debug interfaces. IN the case c6x, now with my change to add debug_dma_mapping_error(), we will start seeing warnings since dma_map_page() and dma_map_single() are debugged with a call to debug_dma_map_page() and the corresponding dma_mapping_error() interface doesn't call debug_dma_mapping_error() interface

Quoted 4 lines

- Does adding get_dma_ops() make sense? Doesn't look like c6x exports dma_ops?

Any other ideas?

I'm not sure. I don't know what get_dma_ops() does and it doesn't seem to be documented anywhere.

Quoted 23 lines · Mark Salter

Quoted 22 lines · Shuah Khan

Quoted 21 lines · Mark Salter

Quoted 6 lines · Shuah Khan

Quoted 5 lines · Shuah Khan

Add support for debug_dma_mapping_error() call to avoid warning from debug_dma_unmap() interface when it checks for mapping error checked status. Without this patch, device driver failed to check map error warning is generated.

Quoted 7 lines

Quoted 4 lines

Signed-off-by Shuah Khan <[email protected]>

---
 arch/c6x/include/asm/dma-mapping.h |    1 +
 1 file changed, 1 insertion(+)

Would you like to this patch go through c6x arch tree or linux-next? Please let me know your preference.

I tried to test this but I get a build error with CONFIG_DMA_API_DEBUG:

/linux-next/lib/dma-debug.c: In function 'has_mapping_error':
/linux-next/lib/dma-debug.c:863:15: error: implicit declaration of function 'get_dma_ops' [-Werror=implicit-function-declaration] /linux-next/lib/dma-debug.c:863:34: warning: initialization makes pointer from integer without a cast [enabled by default]

Quoted 8 lines

Quoted 5 lines

Quoted 2 lines

C6X (along with some other architectures) doesn't have a get_dma_ops() function defined.

That is a problem I didn't think about. I did a check and looks like c6x and frv are the only ones that don't have get_dma_ops() defined. frv is

By my count, there are 14 architectures with get_dma_ops() and 14 without.

Right. I should have explained more. The following archs

arch/avr32/include/asm/dma-mapping.h
arch/blackfin/include/asm/dma-mapping.h
arch/cris/include/asm/dma-mapping.h
arch/mn10300/include/asm/dma-mapping.h
arch/parisc/include/asm/dma-mapping.h
arch/xtensa/include/asm/dma-mapping.h

define dma_map_page() and dma_map_single() and not call debug_dma_map_page() interface. There is no risk of mis-matched debug and non-debug mapping and mapping error checks like in the case of other archs and c6x.

Quoted 8 lines

Quoted 8 lines

in a different category as it doesn't use dma_debug interfaces. IN the case c6x, now with my change to add debug_dma_mapping_error(), we will start seeing warnings since dma_map_page() and dma_map_single() are debugged with a call to debug_dma_map_page() and the corresponding dma_mapping_error() interface doesn't call debug_dma_mapping_error() interface

Quoted 7 lines

Quoted 4 lines

- Does adding get_dma_ops() make sense? Doesn't look like c6x exports dma_ops?

Any other ideas?

I'm not sure. I don't know what get_dma_ops() does and it doesn't seem to be documented anywhere.

It returns pointer to dma_ops like the one on alpha:

static inline struct dma_map_ops *get_dma_ops(struct device *dev)

{
        return dma_ops;
}

c6x doesn't define dma_ops looks like. Is that correct? Returning null from get_dma_ops() is not an option as get_dma_ops() return is assumed to be not null.

Quoted 41 lines · Shuah Khan

Quoted 23 lines · Mark Salter

Quoted 22 lines · Shuah Khan

Quoted 21 lines · Mark Salter

Quoted 6 lines · Shuah Khan

Quoted 5 lines · Shuah Khan

Add support for debug_dma_mapping_error() call to avoid warning from debug_dma_unmap() interface when it checks for mapping error checked status. Without this patch, device driver failed to check map error warning is generated.

Quoted 7 lines

Quoted 4 lines

Signed-off-by Shuah Khan <[email protected]>

---
 arch/c6x/include/asm/dma-mapping.h |    1 +
 1 file changed, 1 insertion(+)

Would you like to this patch go through c6x arch tree or linux-next? Please let me know your preference.

I tried to test this but I get a build error with CONFIG_DMA_API_DEBUG:

/linux-next/lib/dma-debug.c: In function 'has_mapping_error':
/linux-next/lib/dma-debug.c:863:15: error: implicit declaration of function 'get_dma_ops' [-Werror=implicit-function-declaration] /linux-next/lib/dma-debug.c:863:34: warning: initialization makes pointer from integer without a cast [enabled by default]

Quoted 8 lines

Quoted 5 lines

Quoted 2 lines

C6X (along with some other architectures) doesn't have a get_dma_ops() function defined.

That is a problem I didn't think about. I did a check and looks like c6x and frv are the only ones that don't have get_dma_ops() defined. frv is

By my count, there are 14 architectures with get_dma_ops() and 14 without.

Right. I should have explained more. The following archs

arch/avr32/include/asm/dma-mapping.h
arch/blackfin/include/asm/dma-mapping.h
arch/cris/include/asm/dma-mapping.h
arch/mn10300/include/asm/dma-mapping.h
arch/parisc/include/asm/dma-mapping.h
arch/xtensa/include/asm/dma-mapping.h

Quoted 4 lines

define dma_map_page() and dma_map_single() and not call debug_dma_map_page() interface. There is no risk of mis-matched debug and non-debug mapping and mapping error checks like in the case of other archs and c6x.

Ah, okay. Not all architectures support HAVE_DMA_API_DEBUG. So, of those that do, c6x seems to be the only one with dma_ops.

Quoted 16 lines

Quoted 8 lines

Quoted 8 lines

in a different category as it doesn't use dma_debug interfaces. IN the case c6x, now with my change to add debug_dma_mapping_error(), we will start seeing warnings since dma_map_page() and dma_map_single() are debugged with a call to debug_dma_map_page() and the corresponding dma_mapping_error() interface doesn't call debug_dma_mapping_error() interface

Quoted 7 lines

Quoted 4 lines

- Does adding get_dma_ops() make sense? Doesn't look like c6x exports dma_ops?

Any other ideas?

I'm not sure. I don't know what get_dma_ops() does and it doesn't seem to be documented anywhere.

Quoted 6 lines

It returns pointer to dma_ops like the one on alpha:

static inline struct dma_map_ops *get_dma_ops(struct device *dev)

{
        return dma_ops;
}

Okay, so what is dma_ops used for? Looks like maybe supporting different dma features/functionality on different busses/devices.

Quoted 4 lines

c6x doesn't define dma_ops looks like. Is that correct? Returning null from get_dma_ops() is not an option as get_dma_ops() return is assumed to be not null.

As things stand, c6x DMA hw doesn't really need dma_ops and until this patch, I could build in DMA debug support without dma_ops. So do we really want to require dma_ops for dma debug support even for those architectures which don't otherwise need it? I could add dma_ops, but it seems silly to do so only for dma debug.

Quoted 81 lines · Mark Salter

Quoted 41 lines · Shuah Khan

Quoted 23 lines · Mark Salter

Quoted 22 lines · Shuah Khan

Quoted 21 lines · Mark Salter

Quoted 6 lines · Shuah Khan

Quoted 5 lines · Shuah Khan

Add support for debug_dma_mapping_error() call to avoid warning from debug_dma_unmap() interface when it checks for mapping error checked status. Without this patch, device driver failed to check map error warning is generated.

Quoted 7 lines

Quoted 4 lines

Signed-off-by Shuah Khan <[email protected]>

---
 arch/c6x/include/asm/dma-mapping.h |    1 +
 1 file changed, 1 insertion(+)

Would you like to this patch go through c6x arch tree or linux-next? Please let me know your preference.

I tried to test this but I get a build error with CONFIG_DMA_API_DEBUG:

/linux-next/lib/dma-debug.c: In function 'has_mapping_error':
/linux-next/lib/dma-debug.c:863:15: error: implicit declaration of function 'get_dma_ops' [-Werror=implicit-function-declaration] /linux-next/lib/dma-debug.c:863:34: warning: initialization makes pointer from integer without a cast [enabled by default]

Quoted 8 lines

Quoted 5 lines

Quoted 2 lines

C6X (along with some other architectures) doesn't have a get_dma_ops() function defined.

That is a problem I didn't think about. I did a check and looks like c6x and frv are the only ones that don't have get_dma_ops() defined. frv is

By my count, there are 14 architectures with get_dma_ops() and 14 without.

Right. I should have explained more. The following archs

arch/avr32/include/asm/dma-mapping.h
arch/blackfin/include/asm/dma-mapping.h
arch/cris/include/asm/dma-mapping.h
arch/mn10300/include/asm/dma-mapping.h
arch/parisc/include/asm/dma-mapping.h
arch/xtensa/include/asm/dma-mapping.h

Quoted 4 lines

define dma_map_page() and dma_map_single() and not call debug_dma_map_page() interface. There is no risk of mis-matched debug and non-debug mapping and mapping error checks like in the case of other archs and c6x.

Ah, okay. Not all architectures support HAVE_DMA_API_DEBUG. So, of those that do, c6x seems to be the only one with dma_ops.

Quoted 16 lines

Quoted 8 lines

Quoted 8 lines

in a different category as it doesn't use dma_debug interfaces. IN the case c6x, now with my change to add debug_dma_mapping_error(), we will start seeing warnings since dma_map_page() and dma_map_single() are debugged with a call to debug_dma_map_page() and the corresponding dma_mapping_error() interface doesn't call debug_dma_mapping_error() interface

Quoted 7 lines

Quoted 4 lines

- Does adding get_dma_ops() make sense? Doesn't look like c6x exports dma_ops?

Any other ideas?

I'm not sure. I don't know what get_dma_ops() does and it doesn't seem to be documented anywhere.

Quoted 6 lines

It returns pointer to dma_ops like the one on alpha:

static inline struct dma_map_ops *get_dma_ops(struct device *dev)

{
        return dma_ops;
}

Okay, so what is dma_ops used for? Looks like maybe supporting different dma features/functionality on different busses/devices.

Quoted 4 lines

c6x doesn't define dma_ops looks like. Is that correct? Returning null from get_dma_ops() is not an option as get_dma_ops() return is assumed to be not null.

Quoted 5 lines

As things stand, c6x DMA hw doesn't really need dma_ops and until this patch, I could build in DMA debug support without dma_ops. So do we really want to require dma_ops for dma debug support even for those architectures which don't otherwise need it? I could add dma_ops, but it seems silly to do so only for dma debug.

I agree it doesn't make sense to add dma_ops when there is no need to. Until now dma-debug didn't depend on dma_ops. This dependency has been introduced with the debug_dma_mapping_error() interface I added :(

Let me go back and see if I can come up with a way to not require dma_ops for debug-dma.

This is for c6x to go through Marek's tree with all the other arch patches. Hope that is ok with you Mark.

https://lkml.org/lkml/2012/11/3/219 fixes the debug_dma_mapping_error()
dependency on get_dma_ops() that caused compile errors on c6x.