Re: [PATCH] swiotlb: make range_needs_mapping architecture-specific

[FUJITA Tomonori]

On Thu, 21 May 2009 17:15:23 +0100
Ian Campbell <ian.campbell@xxxxxxxxxx> wrote:

> This moves range_needs_mapping() from lib/swiotlb.c to
> arch/*/include/asm/dma-mapping.h and renames it
> swiotlb_arch_force_mapping() to more acurately reflect its usage.
> 
> Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> Cc: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
> Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
> Cc: Becky Bruce <beckyb@xxxxxxxxxxxxxxxxxxx>
> Cc: Olaf Kirch <okir@xxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxx>
> Cc: Greg KH <gregkh@xxxxxxx>
> Cc: xen-devel <xendevel@xxxxxxxxxxxxxxxxxxx>
> Cc: x86 maintainers <x86@xxxxxxxxxx>
> Cc: lkml <linux-kernel@xxxxxxxxxxxxxxx>
> ---
>  arch/ia64/include/asm/dma-mapping.h    |    5 +++++
>  arch/powerpc/include/asm/dma-mapping.h |    5 +++++
>  arch/x86/include/asm/dma-mapping.h     |    9 +++++++++
>  arch/x86/kernel/pci-swiotlb.c          |    2 ++
>  include/linux/swiotlb.h                |    2 --
>  lib/swiotlb.c                          |   13 ++++---------
>  6 files changed, 25 insertions(+), 11 deletions(-)
> 
> diff --git a/arch/ia64/include/asm/dma-mapping.h b/arch/ia64/include/asm/dma-mapping.h
> index a091648..3e8fb31 100644
> --- a/arch/ia64/include/asm/dma-mapping.h
> +++ b/arch/ia64/include/asm/dma-mapping.h
> @@ -180,4 +180,9 @@ static inline int is_buffer_dma_capable(struct device *dev, u64 mask,
>  	return addr + size <= mask;
>  }
>  
> +static inline int swiotlb_force_mapping(phys_addr_t paddr, size_t size)
> +{
> +       return 0;
> +}
> +
>  #endif /* _ASM_IA64_DMA_MAPPING_H */
> diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
> index c69f2b5..7e3510d 100644
> --- a/arch/powerpc/include/asm/dma-mapping.h
> +++ b/arch/powerpc/include/asm/dma-mapping.h
> @@ -429,5 +429,10 @@ static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
>  	__dma_sync(vaddr, size, (int)direction);
>  }
>  
> +static inline int swiotlb_force_mapping(phys_addr_t paddr, size_t size)
> +{
> +	return 0;
> +}
> +

Adding a swiotlb specific function to asm/dma-mapping.h is wrong.


>  #endif /* __KERNEL__ */
>  #endif	/* _ASM_DMA_MAPPING_H */
> diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
> index 52b8d36..aa9639f 100644
> --- a/arch/x86/include/asm/dma-mapping.h
> +++ b/arch/x86/include/asm/dma-mapping.h
> @@ -315,4 +315,13 @@ static inline int is_buffer_dma_capable(struct device *dev, u64 mask,
>  	return addr + size <= mask;
>  }
>  
> +extern int (*x86_swiotlb_force_mapping)(phys_addr_t paddr, size_t size);
> +
> +static inline int swiotlb_force_mapping(phys_addr_t paddr, size_t size)
> +{
> +	if (x86_swiotlb_force_mapping)
> +		return x86_swiotlb_force_mapping(paddr, size);
> +	return 0;
> +}
> +
>  #endif
> diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
> index 7267376..d48912c 100644
> --- a/arch/x86/kernel/pci-swiotlb.c
> +++ b/arch/x86/kernel/pci-swiotlb.c
> @@ -15,6 +15,8 @@
>  
>  int swiotlb __read_mostly;
>  
> +int (*x86_swiotlb_force_mapping)(phys_addr_t paddr, size_t size);
> +
>  static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
>  					dma_addr_t *dma_handle, gfp_t flags)
>  {
> diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
> index cb1a663..32f4fa4 100644
> --- a/include/linux/swiotlb.h
> +++ b/include/linux/swiotlb.h
> @@ -32,8 +32,6 @@ extern dma_addr_t swiotlb_phys_to_bus(struct device *hwdev,
>  extern phys_addr_t swiotlb_bus_to_phys(struct device *hwdev,
>  				       dma_addr_t address);

Ditto.

And using a function pointer for the architecture abstraction is worse
than __weak.


> -extern int swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size);
> -
>  extern void
>  *swiotlb_alloc_coherent(struct device *hwdev, size_t size,
>  			dma_addr_t *dma_handle, gfp_t flags);
> diff --git a/lib/swiotlb.c b/lib/swiotlb.c
> index 98726a2..d311654 100644
> --- a/lib/swiotlb.c
> +++ b/lib/swiotlb.c
> @@ -147,11 +147,6 @@ void * __weak swiotlb_bus_to_virt(struct device *hwdev, dma_addr_t address)
>  	return phys_to_virt(swiotlb_bus_to_phys(hwdev, address));
>  }
>  
> -int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
> -{
> -	return 0;
> -}
> -
>  static void swiotlb_print_info(unsigned long bytes)
>  {
>  	phys_addr_t pstart, pend;
> @@ -312,9 +307,9 @@ cleanup1:
>  	return -ENOMEM;
>  }
>  
> -static inline int range_needs_mapping(phys_addr_t paddr, size_t size)
> +static inline int force_mapping(phys_addr_t paddr, size_t size)
>  {
> -	return swiotlb_force || swiotlb_arch_range_needs_mapping(paddr, size);
> +	return swiotlb_force || swiotlb_force_mapping(paddr, size);
>  }
>  
>  static int is_swiotlb_buffer(char *addr)
> @@ -647,7 +642,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
>  	 * buffering it.
>  	 */
>  	if (is_buffer_dma_capable(dev, dma_get_mask(dev), dev_addr, size) &&
> -	    !range_needs_mapping(phys, size))
> +	    !force_mapping(phys, size))
>  		return dev_addr;
>  
>  	/*
> @@ -810,7 +805,7 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
>  		phys_addr_t paddr = sg_phys(sg);
>  		dma_addr_t dev_addr = swiotlb_phys_to_bus(hwdev, paddr);
>  
> -		if (range_needs_mapping(paddr, sg->length) ||
> +		if (force_mapping(paddr, sg->length) ||
>  		    !is_buffer_dma_capable(hwdev, dma_get_mask(hwdev),
>  					   dev_addr, sg->length)) {
>  			void *map = map_single(hwdev, sg_phys(sg),
> -- 
> 1.5.6.5
> 
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