Re: [PATCH v9 01/18] arm: make SWIOTLB available

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Tue, Oct 29, 2013 at 04:41:40AM +0000, Stefano Stabellini wrote:
> ping?

You know you are pinging yourself, right ? :-)

> 
> On Fri, 25 Oct 2013, Stefano Stabellini wrote:
> > Russell,
> > this is the only patch that needs an ack at the moment.
> > As you commented on it before and I have already addressed your comments
> > few versions ago, unless you have any complaints I am going to add it to
> > linux-next and I am thinking of merging it during the next merge window.
> > 
> > On Fri, 25 Oct 2013, Stefano Stabellini wrote:
> > > IOMMU_HELPER is needed because SWIOTLB calls iommu_is_span_boundary,
> > > provided by lib/iommu_helper.c.
> > > 
> > > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> > > Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> > > CC: will.deacon@arm.com
> > > CC: linux@arm.linux.org.uk
> > > 
> > > 
> > > Changes in v8:
> > > - use __phys_to_pfn and __pfn_to_phys.
> > > 
> > > Changes in v7:
> > > - dma_mark_clean: empty implementation;
> > > - in dma_capable use coherent_dma_mask if dma_mask hasn't been
> > >   allocated.
> > > 
> > > Changes in v6:
> > > - check for dev->dma_mask being NULL in dma_capable.
> > > 
> > > Changes in v5:
> > > - implement dma_mark_clean using dmac_flush_range.
> > > 
> > > Changes in v3:
> > > - dma_capable: do not treat dma_mask as a limit;
> > > - remove SWIOTLB dependency on NEED_SG_DMA_LENGTH.
> > > ---
> > >  arch/arm/Kconfig                   |    6 +++++
> > >  arch/arm/include/asm/dma-mapping.h |   37 ++++++++++++++++++++++++++++++++++++
> > >  2 files changed, 43 insertions(+), 0 deletions(-)
> > > 
> > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> > > index 1ad6fb6..b08374f 100644
> > > --- a/arch/arm/Kconfig
> > > +++ b/arch/arm/Kconfig
> > > @@ -1872,6 +1872,12 @@ config CC_STACKPROTECTOR
> > >  	  neutralized via a kernel panic.
> > >  	  This feature requires gcc version 4.2 or above.
> > >  
> > > +config SWIOTLB
> > > +	def_bool y
> > > +
> > > +config IOMMU_HELPER
> > > +	def_bool SWIOTLB
> > > +
> > >  config XEN_DOM0
> > >  	def_bool y
> > >  	depends on XEN
> > > diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
> > > index 5b579b9..01b5a3d 100644
> > > --- a/arch/arm/include/asm/dma-mapping.h
> > > +++ b/arch/arm/include/asm/dma-mapping.h
> > > @@ -10,6 +10,7 @@
> > >  
> > >  #include <asm-generic/dma-coherent.h>
> > >  #include <asm/memory.h>
> > > +#include <asm/cacheflush.h>
> > >  
> > >  #define DMA_ERROR_CODE	(~0)
> > >  extern struct dma_map_ops arm_dma_ops;
> > > @@ -86,6 +87,42 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
> > >  }
> > >  #endif
> > >  
> > > +static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
> > > +{
> > > +	unsigned int offset = paddr & ~PAGE_MASK;
> > > +	return pfn_to_dma(dev, __phys_to_pfn(paddr)) + offset;
> > > +}
> > > +
> > > +static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
> > > +{
> > > +	unsigned int offset = dev_addr & ~PAGE_MASK;
> > > +	return __pfn_to_phys(dma_to_pfn(dev, dev_addr)) + offset;
> > > +}
> > > +
> > > +static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
> > > +{
> > > +	u64 limit, mask;
> > > +	
> > > +	if (dev->dma_mask)
> > > +		mask = *dev->dma_mask;
> > > +	else 
> > > +		mask = dev->coherent_dma_mask;
> > > +
> > > +	if (mask == 0)
> > > +		return 0;
> > > +
> > > +	limit = (mask + 1) & ~mask;
> > > +	if (limit && size > limit)
> > > +		return 0;
> > > +
> > > +	if ((addr | (addr + size - 1)) & ~mask)
> > > +		return 0;
> > > +
> > > +	return 1;
> > > +}
> > > +
> > > +static inline void dma_mark_clean(void *addr, size_t size) { }
> > > +
> > >  /*
> > >   * DMA errors are defined by all-bits-set in the DMA address.
> > >   */
> > > -- 
> > > 1.7.2.5
> > > 
> >