Re: [PATCH v4 6/6] arm: dma-mapping: updates to limit dma_mask and iommu mapping size

2015-01-27 Thread Murali Karicheri

On 01/27/2015 06:34 AM, Catalin Marinas wrote:

On Tue, Jan 27, 2015 at 11:12:32AM +, Robin Murphy wrote:

On 23/01/15 22:32, Murali Karicheri wrote:

Limit the dma_mask to minimum of dma_mask and dma_base + size - 1.

Also arm_iommu_create_mapping() has size parameter of size_t and
arm_setup_iommu_dma_ops() can take a value higher than that. So
limit the size to SIZE_MAX.

Signed-off-by: Murali Karicheri
---
   arch/arm/mm/dma-mapping.c |   10 ++
   1 file changed, 10 insertions(+)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 7864797..a1f9030 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -2004,6 +2004,13 @@ static bool arm_setup_iommu_dma_ops(struct device *dev, 
u64 dma_base, u64 size,
if (!iommu)
return false;

+   /*
+* currently arm_iommu_create_mapping() takes a max of size_t
+* for size param. So check this limit for now.
+*/
+   if (size>  SIZE_MAX)
+   return false;
+
mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
if (IS_ERR(mapping)) {
pr_warn("Failed to create %llu-byte IOMMU mapping for device 
%s\n",
@@ -2053,6 +2060,9 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, 
u64 size,
   {
struct dma_map_ops *dma_ops;

+   /* limit dma_mask to the lower of the two values */
+   *dev->dma_mask = min((*dev->dma_mask), (dma_base + size - 1));
+


Is there any reason not to do this in of_dma_configure? It seems like
something everyone could benefit from - I'd cooked up a dodgy workaround
for the same issue in my arm64 IOMMU code, but handling it generically
in common code would be much nicer.


Ok Will move this to of_dma_configure().

Murali



I agree. I started something here:

http://article.gmane.org/gmane.linux.kernel/1835096

but I don't remember to have got to a clear conclusion.




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Linux Kernel, Texas Instruments
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Re: [PATCH v4 6/6] arm: dma-mapping: updates to limit dma_mask and iommu mapping size

2015-01-27 Thread Catalin Marinas
On Tue, Jan 27, 2015 at 11:12:32AM +, Robin Murphy wrote:
> On 23/01/15 22:32, Murali Karicheri wrote:
> > Limit the dma_mask to minimum of dma_mask and dma_base + size - 1.
> >
> > Also arm_iommu_create_mapping() has size parameter of size_t and
> > arm_setup_iommu_dma_ops() can take a value higher than that. So
> > limit the size to SIZE_MAX.
> >
> > Signed-off-by: Murali Karicheri 
> > ---
> >   arch/arm/mm/dma-mapping.c |   10 ++
> >   1 file changed, 10 insertions(+)
> >
> > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> > index 7864797..a1f9030 100644
> > --- a/arch/arm/mm/dma-mapping.c
> > +++ b/arch/arm/mm/dma-mapping.c
> > @@ -2004,6 +2004,13 @@ static bool arm_setup_iommu_dma_ops(struct device 
> > *dev, u64 dma_base, u64 size,
> > if (!iommu)
> > return false;
> >
> > +   /*
> > +* currently arm_iommu_create_mapping() takes a max of size_t
> > +* for size param. So check this limit for now.
> > +*/
> > +   if (size > SIZE_MAX)
> > +   return false;
> > +
> > mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
> > if (IS_ERR(mapping)) {
> > pr_warn("Failed to create %llu-byte IOMMU mapping for device 
> > %s\n",
> > @@ -2053,6 +2060,9 @@ void arch_setup_dma_ops(struct device *dev, u64 
> > dma_base, u64 size,
> >   {
> > struct dma_map_ops *dma_ops;
> >
> > +   /* limit dma_mask to the lower of the two values */
> > +   *dev->dma_mask = min((*dev->dma_mask), (dma_base + size - 1));
> > +
> 
> Is there any reason not to do this in of_dma_configure? It seems like 
> something everyone could benefit from - I'd cooked up a dodgy workaround 
> for the same issue in my arm64 IOMMU code, but handling it generically 
> in common code would be much nicer.

I agree. I started something here:

http://article.gmane.org/gmane.linux.kernel/1835096

but I don't remember to have got to a clear conclusion.

-- 
Catalin
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Re: [PATCH v4 6/6] arm: dma-mapping: updates to limit dma_mask and iommu mapping size

2015-01-27 Thread Robin Murphy

Hi Murali,

On 23/01/15 22:32, Murali Karicheri wrote:

Limit the dma_mask to minimum of dma_mask and dma_base + size - 1.

Also arm_iommu_create_mapping() has size parameter of size_t and
arm_setup_iommu_dma_ops() can take a value higher than that. So
limit the size to SIZE_MAX.

Signed-off-by: Murali Karicheri 
---
  arch/arm/mm/dma-mapping.c |   10 ++
  1 file changed, 10 insertions(+)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 7864797..a1f9030 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -2004,6 +2004,13 @@ static bool arm_setup_iommu_dma_ops(struct device *dev, 
u64 dma_base, u64 size,
if (!iommu)
return false;

+   /*
+* currently arm_iommu_create_mapping() takes a max of size_t
+* for size param. So check this limit for now.
+*/
+   if (size > SIZE_MAX)
+   return false;
+
mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
if (IS_ERR(mapping)) {
pr_warn("Failed to create %llu-byte IOMMU mapping for device 
%s\n",
@@ -2053,6 +2060,9 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, 
u64 size,
  {
struct dma_map_ops *dma_ops;

+   /* limit dma_mask to the lower of the two values */
+   *dev->dma_mask = min((*dev->dma_mask), (dma_base + size - 1));
+


Is there any reason not to do this in of_dma_configure? It seems like 
something everyone could benefit from - I'd cooked up a dodgy workaround 
for the same issue in my arm64 IOMMU code, but handling it generically 
in common code would be much nicer.


Robin.


dev->archdata.dma_coherent = coherent;
if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu))
dma_ops = arm_get_iommu_dma_map_ops(coherent);




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[PATCH v4 6/6] arm: dma-mapping: updates to limit dma_mask and iommu mapping size

2015-01-23 Thread Murali Karicheri
Limit the dma_mask to minimum of dma_mask and dma_base + size - 1.

Also arm_iommu_create_mapping() has size parameter of size_t and
arm_setup_iommu_dma_ops() can take a value higher than that. So
limit the size to SIZE_MAX.

Signed-off-by: Murali Karicheri 
---
 arch/arm/mm/dma-mapping.c |   10 ++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 7864797..a1f9030 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -2004,6 +2004,13 @@ static bool arm_setup_iommu_dma_ops(struct device *dev, 
u64 dma_base, u64 size,
if (!iommu)
return false;
 
+   /*
+* currently arm_iommu_create_mapping() takes a max of size_t
+* for size param. So check this limit for now.
+*/
+   if (size > SIZE_MAX)
+   return false;
+
mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
if (IS_ERR(mapping)) {
pr_warn("Failed to create %llu-byte IOMMU mapping for device 
%s\n",
@@ -2053,6 +2060,9 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, 
u64 size,
 {
struct dma_map_ops *dma_ops;
 
+   /* limit dma_mask to the lower of the two values */
+   *dev->dma_mask = min((*dev->dma_mask), (dma_base + size - 1));
+
dev->archdata.dma_coherent = coherent;
if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu))
dma_ops = arm_get_iommu_dma_map_ops(coherent);
-- 
1.7.9.5

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