| Message ID | 1410868485-4143-2-git-send-email-m.szyprowski@samsung.com |
|---|---|
| State | New |
| Headers | show |
Hi Marek, On Tue, Sep 16, 2014 at 12:54:28PM +0100, Marek Szyprowski wrote: > If device has no max_seg_size set, we assume that there is no limit and > force it to DMA_BIT_MASK(32) to always use contiguous mappings in DMA > address space. > > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> > --- > arch/arm/mm/dma-mapping.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index bcd5f836f27e..84705e24571b 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -2050,6 +2050,22 @@ int arm_iommu_attach_device(struct device *dev, > { > int err; > > + /* > + * if device has no max_seg_size set, we assume that there is no limit > + * and force it to DMA_BIT_MASK(32) to always use contiguous mappings > + * in DMA address space > + */ > + if (!dev->dma_parms) { > + dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL); > + if (!dev->dma_parms) > + return -ENOMEM; > + } > + if (!dev->dma_parms->max_segment_size) { > + err = dma_set_max_seg_size(dev, DMA_BIT_MASK(32)); Would it make more sense to base this default value off the dma_mask? In my IOMMU series, of_dma_configure passes back a size parameter to arch_setup_dma_ops which is calculated from the dma-ranges property or the coherent dma mask if the ranges property is absent, so maybe we should set this there too? Will -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello, On 2014-09-24 19:06, Will Deacon wrote: > Hi Marek, > > On Tue, Sep 16, 2014 at 12:54:28PM +0100, Marek Szyprowski wrote: >> If device has no max_seg_size set, we assume that there is no limit and >> force it to DMA_BIT_MASK(32) to always use contiguous mappings in DMA >> address space. >> >> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> >> --- >> arch/arm/mm/dma-mapping.c | 16 ++++++++++++++++ >> 1 file changed, 16 insertions(+) >> >> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c >> index bcd5f836f27e..84705e24571b 100644 >> --- a/arch/arm/mm/dma-mapping.c >> +++ b/arch/arm/mm/dma-mapping.c >> @@ -2050,6 +2050,22 @@ int arm_iommu_attach_device(struct device *dev, >> { >> int err; >> >> + /* >> + * if device has no max_seg_size set, we assume that there is no limit >> + * and force it to DMA_BIT_MASK(32) to always use contiguous mappings >> + * in DMA address space >> + */ >> + if (!dev->dma_parms) { >> + dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL); >> + if (!dev->dma_parms) >> + return -ENOMEM; >> + } >> + if (!dev->dma_parms->max_segment_size) { >> + err = dma_set_max_seg_size(dev, DMA_BIT_MASK(32)); > Would it make more sense to base this default value off the dma_mask? > In my IOMMU series, of_dma_configure passes back a size parameter to > arch_setup_dma_ops which is calculated from the dma-ranges property or the > coherent dma mask if the ranges property is absent, so maybe we should set > this there too? Right, good idea. This patch predates your arch_setup_dma_ops changes, so I had to use something. The value taken from dma_mask is much better than hardcoded DMA_BIT_MASK(32). Do you want to include an updated patch in next version of your arch_setup_dma_ops patchset? Best regards
On Thu, Sep 25, 2014 at 11:43:35AM +0100, Marek Szyprowski wrote: > On 2014-09-24 19:06, Will Deacon wrote: > > On Tue, Sep 16, 2014 at 12:54:28PM +0100, Marek Szyprowski wrote: > >> If device has no max_seg_size set, we assume that there is no limit and > >> force it to DMA_BIT_MASK(32) to always use contiguous mappings in DMA > >> address space. > >> > >> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> > >> --- > >> arch/arm/mm/dma-mapping.c | 16 ++++++++++++++++ > >> 1 file changed, 16 insertions(+) > >> > >> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > >> index bcd5f836f27e..84705e24571b 100644 > >> --- a/arch/arm/mm/dma-mapping.c > >> +++ b/arch/arm/mm/dma-mapping.c > >> @@ -2050,6 +2050,22 @@ int arm_iommu_attach_device(struct device *dev, > >> { > >> int err; > >> > >> + /* > >> + * if device has no max_seg_size set, we assume that there is no limit > >> + * and force it to DMA_BIT_MASK(32) to always use contiguous mappings > >> + * in DMA address space > >> + */ > >> + if (!dev->dma_parms) { > >> + dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL); > >> + if (!dev->dma_parms) > >> + return -ENOMEM; > >> + } > >> + if (!dev->dma_parms->max_segment_size) { > >> + err = dma_set_max_seg_size(dev, DMA_BIT_MASK(32)); > > Would it make more sense to base this default value off the dma_mask? > > In my IOMMU series, of_dma_configure passes back a size parameter to > > arch_setup_dma_ops which is calculated from the dma-ranges property or the > > coherent dma mask if the ranges property is absent, so maybe we should set > > this there too? > > Right, good idea. This patch predates your arch_setup_dma_ops changes, so I > had to use something. The value taken from dma_mask is much better than > hardcoded > DMA_BIT_MASK(32). Do you want to include an updated patch in next > version of your > arch_setup_dma_ops patchset? Sure, I'll have a go at rolling that in. Cheers, Will -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index bcd5f836f27e..84705e24571b 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -2050,6 +2050,22 @@ int arm_iommu_attach_device(struct device *dev, { int err; + /* + * if device has no max_seg_size set, we assume that there is no limit + * and force it to DMA_BIT_MASK(32) to always use contiguous mappings + * in DMA address space + */ + if (!dev->dma_parms) { + dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL); + if (!dev->dma_parms) + return -ENOMEM; + } + if (!dev->dma_parms->max_segment_size) { + err = dma_set_max_seg_size(dev, DMA_BIT_MASK(32)); + if (err) + return err; + } + err = iommu_attach_device(mapping->domain, dev); if (err) return err;
If device has no max_seg_size set, we assume that there is no limit and force it to DMA_BIT_MASK(32) to always use contiguous mappings in DMA address space. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> --- arch/arm/mm/dma-mapping.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)