diff mbox

[Xen-devel,v9,05/13] arm: introduce is_device_dma_coherent

Message ID 1415792454-23161-5-git-send-email-stefano.stabellini@eu.citrix.com
State New
Headers show

Commit Message

Stefano Stabellini Nov. 12, 2014, 11:40 a.m. UTC
Introduce a boolean flag and an accessor function to check whether a
device is dma_coherent. Set the flag from set_arch_dma_coherent_ops.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
CC: linux@arm.linux.org.uk
---
 arch/arm/include/asm/device.h      |    1 +
 arch/arm/include/asm/dma-mapping.h |    6 ++++++
 2 files changed, 7 insertions(+)

Comments

Stefano Stabellini Nov. 14, 2014, 11:59 a.m. UTC | #1
Russell,
this patch needs your feedback.

- Stefano

On Wed, 12 Nov 2014, Stefano Stabellini wrote:
> Introduce a boolean flag and an accessor function to check whether a
> device is dma_coherent. Set the flag from set_arch_dma_coherent_ops.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
> CC: linux@arm.linux.org.uk
> ---
>  arch/arm/include/asm/device.h      |    1 +
>  arch/arm/include/asm/dma-mapping.h |    6 ++++++
>  2 files changed, 7 insertions(+)
> 
> diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h
> index dc662fc..4111592 100644
> --- a/arch/arm/include/asm/device.h
> +++ b/arch/arm/include/asm/device.h
> @@ -17,6 +17,7 @@ struct dev_archdata {
>  #ifdef CONFIG_ARM_DMA_USE_IOMMU
>  	struct dma_iommu_mapping	*mapping;
>  #endif
> +	bool dma_coherent;
>  };
>  
>  struct omap_device;
> diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
> index 85738b2..8c3b616 100644
> --- a/arch/arm/include/asm/dma-mapping.h
> +++ b/arch/arm/include/asm/dma-mapping.h
> @@ -123,11 +123,17 @@ static inline unsigned long dma_max_pfn(struct device *dev)
>  
>  static inline int set_arch_dma_coherent_ops(struct device *dev)
>  {
> +	dev->archdata.dma_coherent = true;
>  	set_dma_ops(dev, &arm_coherent_dma_ops);
>  	return 0;
>  }
>  #define set_arch_dma_coherent_ops(dev)	set_arch_dma_coherent_ops(dev)
>  
> +static inline bool is_device_dma_coherent(struct device *dev)
> +{
> +	return dev->archdata.dma_coherent;
> +}
> +
>  static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
>  {
>  	unsigned int offset = paddr & ~PAGE_MASK;
> -- 
> 1.7.10.4
> 
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Stefano Stabellini Nov. 18, 2014, 4:49 p.m. UTC | #2
ping?

On Fri, 14 Nov 2014, Stefano Stabellini wrote:
> Russell,
> this patch needs your feedback.
> 
> - Stefano
> 
> On Wed, 12 Nov 2014, Stefano Stabellini wrote:
> > Introduce a boolean flag and an accessor function to check whether a
> > device is dma_coherent. Set the flag from set_arch_dma_coherent_ops.
> > 
> > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
> > Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
> > CC: linux@arm.linux.org.uk
> > ---
> >  arch/arm/include/asm/device.h      |    1 +
> >  arch/arm/include/asm/dma-mapping.h |    6 ++++++
> >  2 files changed, 7 insertions(+)
> > 
> > diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h
> > index dc662fc..4111592 100644
> > --- a/arch/arm/include/asm/device.h
> > +++ b/arch/arm/include/asm/device.h
> > @@ -17,6 +17,7 @@ struct dev_archdata {
> >  #ifdef CONFIG_ARM_DMA_USE_IOMMU
> >  	struct dma_iommu_mapping	*mapping;
> >  #endif
> > +	bool dma_coherent;
> >  };
> >  
> >  struct omap_device;
> > diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
> > index 85738b2..8c3b616 100644
> > --- a/arch/arm/include/asm/dma-mapping.h
> > +++ b/arch/arm/include/asm/dma-mapping.h
> > @@ -123,11 +123,17 @@ static inline unsigned long dma_max_pfn(struct device *dev)
> >  
> >  static inline int set_arch_dma_coherent_ops(struct device *dev)
> >  {
> > +	dev->archdata.dma_coherent = true;
> >  	set_dma_ops(dev, &arm_coherent_dma_ops);
> >  	return 0;
> >  }
> >  #define set_arch_dma_coherent_ops(dev)	set_arch_dma_coherent_ops(dev)
> >  
> > +static inline bool is_device_dma_coherent(struct device *dev)
> > +{
> > +	return dev->archdata.dma_coherent;
> > +}
> > +
> >  static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
> >  {
> >  	unsigned int offset = paddr & ~PAGE_MASK;
> > -- 
> > 1.7.10.4
> > 
> 
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Russell King - ARM Linux Nov. 20, 2014, 12:07 a.m. UTC | #3
On Tue, Nov 18, 2014 at 04:49:21PM +0000, Stefano Stabellini wrote:
> ping?

Sending something which wants my attention _To:_ me is always a good idea :)

The patch is fine in itself, but I have a niggle about the
is_device_dma_coherent() - provided this is only used in architecture
specific code, that should be fine.  It could probably do with a comment
to that effect in an attempt to discourage drivers using it (thereby
becoming less portable to other architectures.)
Stefano Stabellini Nov. 20, 2014, 10:39 a.m. UTC | #4
On Thu, 20 Nov 2014, Russell King - ARM Linux wrote:
> On Tue, Nov 18, 2014 at 04:49:21PM +0000, Stefano Stabellini wrote:
> > ping?
> 
> Sending something which wants my attention _To:_ me is always a good idea :)

I'll keep that in mind :-)


> The patch is fine in itself, but I have a niggle about the
> is_device_dma_coherent() - provided this is only used in architecture
> specific code, that should be fine.  It could probably do with a comment
> to that effect in an attempt to discourage drivers using it (thereby
> becoming less portable to other architectures.)

Can I take this as an Acked-by?
Good point regarding the comment. Maybe I can add:

/* do not use this function in a driver */
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Russell King - ARM Linux Nov. 21, 2014, 3:29 p.m. UTC | #5
On Thu, Nov 20, 2014 at 10:39:32AM +0000, Stefano Stabellini wrote:
> On Thu, 20 Nov 2014, Russell King - ARM Linux wrote:
> > On Tue, Nov 18, 2014 at 04:49:21PM +0000, Stefano Stabellini wrote:
> > > ping?
> > 
> > Sending something which wants my attention _To:_ me is always a good idea :)
> 
> I'll keep that in mind :-)
> 
> 
> > The patch is fine in itself, but I have a niggle about the
> > is_device_dma_coherent() - provided this is only used in architecture
> > specific code, that should be fine.  It could probably do with a comment
> > to that effect in an attempt to discourage drivers using it (thereby
> > becoming less portable to other architectures.)
> 
> Can I take this as an Acked-by?
> Good point regarding the comment. Maybe I can add:
> 
> /* do not use this function in a driver */

Provided it gets such a comment, yes.  Thanks.
diff mbox

Patch

diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h
index dc662fc..4111592 100644
--- a/arch/arm/include/asm/device.h
+++ b/arch/arm/include/asm/device.h
@@ -17,6 +17,7 @@  struct dev_archdata {
 #ifdef CONFIG_ARM_DMA_USE_IOMMU
 	struct dma_iommu_mapping	*mapping;
 #endif
+	bool dma_coherent;
 };
 
 struct omap_device;
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 85738b2..8c3b616 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -123,11 +123,17 @@  static inline unsigned long dma_max_pfn(struct device *dev)
 
 static inline int set_arch_dma_coherent_ops(struct device *dev)
 {
+	dev->archdata.dma_coherent = true;
 	set_dma_ops(dev, &arm_coherent_dma_ops);
 	return 0;
 }
 #define set_arch_dma_coherent_ops(dev)	set_arch_dma_coherent_ops(dev)
 
+static inline bool is_device_dma_coherent(struct device *dev)
+{
+	return dev->archdata.dma_coherent;
+}
+
 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
 {
 	unsigned int offset = paddr & ~PAGE_MASK;