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Date:   Mon, 9 Sep 2019 17:18:32 -0700 (PDT)
From:   Stefano Stabellini <sstabellini@kernel.org>
To:     Christoph Hellwig <hch@lst.de>
cc:     Stefano Stabellini <sstabellini@kernel.org>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        gross@suse.com, boris.ostrovsky@oracle.com, x86@kernel.org,
        linux-arm-kernel@lists.infradead.org,
        xen-devel@lists.xenproject.org, iommu@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 02/11] xen/arm: consolidate page-coherent.h
In-Reply-To: <20190905113408.3104-3-hch@lst.de>
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References: <20190905113408.3104-1-hch@lst.de> <20190905113408.3104-3-hch@lst.de>
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On Thu, 5 Sep 2019, Christoph Hellwig wrote:
> Shared the duplicate arm/arm64 code in include/xen/arm/page-coherent.h.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>


> ---
>  arch/arm/include/asm/xen/page-coherent.h   | 75 --------------------
>  arch/arm64/include/asm/xen/page-coherent.h | 75 --------------------
>  include/xen/arm/page-coherent.h            | 80 ++++++++++++++++++++++
>  3 files changed, 80 insertions(+), 150 deletions(-)
> 
> diff --git a/arch/arm/include/asm/xen/page-coherent.h b/arch/arm/include/asm/xen/page-coherent.h
> index 602ac02f154c..27e984977402 100644
> --- a/arch/arm/include/asm/xen/page-coherent.h
> +++ b/arch/arm/include/asm/xen/page-coherent.h
> @@ -1,77 +1,2 @@
>  /* SPDX-License-Identifier: GPL-2.0 */
> -#ifndef _ASM_ARM_XEN_PAGE_COHERENT_H
> -#define _ASM_ARM_XEN_PAGE_COHERENT_H
> -
> -#include <linux/dma-mapping.h>
> -#include <asm/page.h>
>  #include <xen/arm/page-coherent.h>
> -
> -static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
> -		dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs)
> -{
> -	return dma_direct_alloc(hwdev, size, dma_handle, flags, attrs);
> -}
> -
> -static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
> -		void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs)
> -{
> -	dma_direct_free(hwdev, size, cpu_addr, dma_handle, attrs);
> -}
> -
> -static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
> -		dma_addr_t handle, size_t size, enum dma_data_direction dir)
> -{
> -	unsigned long pfn = PFN_DOWN(handle);
> -
> -	if (pfn_valid(pfn))
> -		dma_direct_sync_single_for_cpu(hwdev, handle, size, dir);
> -	else
> -		__xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
> -}
> -
> -static inline void xen_dma_sync_single_for_device(struct device *hwdev,
> -		dma_addr_t handle, size_t size, enum dma_data_direction dir)
> -{
> -	unsigned long pfn = PFN_DOWN(handle);
> -	if (pfn_valid(pfn))
> -		dma_direct_sync_single_for_device(hwdev, handle, size, dir);
> -	else
> -		__xen_dma_sync_single_for_device(hwdev, handle, size, dir);
> -}
> -
> -static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
> -	     dma_addr_t dev_addr, unsigned long offset, size_t size,
> -	     enum dma_data_direction dir, unsigned long attrs)
> -{
> -	unsigned long page_pfn = page_to_xen_pfn(page);
> -	unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr);
> -	unsigned long compound_pages =
> -		(1<<compound_order(page)) * XEN_PFN_PER_PAGE;
> -	bool local = (page_pfn <= dev_pfn) &&
> -		(dev_pfn - page_pfn < compound_pages);
> -
> -	if (local)
> -		dma_direct_map_page(hwdev, page, offset, size, dir, attrs);
> -	else
> -		__xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
> -}
> -
> -static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
> -		size_t size, enum dma_data_direction dir, unsigned long attrs)
> -{
> -	unsigned long pfn = PFN_DOWN(handle);
> -	/*
> -	 * Dom0 is mapped 1:1, while the Linux page can be spanned accross
> -	 * multiple Xen page, it's not possible to have a mix of local and
> -	 * foreign Xen page. Dom0 is mapped 1:1, so calling pfn_valid on a
> -	 * foreign mfn will always return false. If the page is local we can
> -	 * safely call the native dma_ops function, otherwise we call the xen
> -	 * specific function.
> -	 */
> -	if (pfn_valid(pfn))
> -		dma_direct_unmap_page(hwdev, handle, size, dir, attrs);
> -	else
> -		__xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
> -}
> -
> -#endif /* _ASM_ARM_XEN_PAGE_COHERENT_H */
> diff --git a/arch/arm64/include/asm/xen/page-coherent.h b/arch/arm64/include/asm/xen/page-coherent.h
> index d88e56b90b93..27e984977402 100644
> --- a/arch/arm64/include/asm/xen/page-coherent.h
> +++ b/arch/arm64/include/asm/xen/page-coherent.h
> @@ -1,77 +1,2 @@
>  /* SPDX-License-Identifier: GPL-2.0 */
> -#ifndef _ASM_ARM64_XEN_PAGE_COHERENT_H
> -#define _ASM_ARM64_XEN_PAGE_COHERENT_H
> -
> -#include <linux/dma-mapping.h>
> -#include <asm/page.h>
>  #include <xen/arm/page-coherent.h>
> -
> -static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
> -		dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs)
> -{
> -	return dma_direct_alloc(hwdev, size, dma_handle, flags, attrs);
> -}
> -
> -static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
> -		void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs)
> -{
> -	dma_direct_free(hwdev, size, cpu_addr, dma_handle, attrs);
> -}
> -
> -static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
> -		dma_addr_t handle, size_t size, enum dma_data_direction dir)
> -{
> -	unsigned long pfn = PFN_DOWN(handle);
> -
> -	if (pfn_valid(pfn))
> -		dma_direct_sync_single_for_cpu(hwdev, handle, size, dir);
> -	else
> -		__xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
> -}
> -
> -static inline void xen_dma_sync_single_for_device(struct device *hwdev,
> -		dma_addr_t handle, size_t size, enum dma_data_direction dir)
> -{
> -	unsigned long pfn = PFN_DOWN(handle);
> -	if (pfn_valid(pfn))
> -		dma_direct_sync_single_for_device(hwdev, handle, size, dir);
> -	else
> -		__xen_dma_sync_single_for_device(hwdev, handle, size, dir);
> -}
> -
> -static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
> -	     dma_addr_t dev_addr, unsigned long offset, size_t size,
> -	     enum dma_data_direction dir, unsigned long attrs)
> -{
> -	unsigned long page_pfn = page_to_xen_pfn(page);
> -	unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr);
> -	unsigned long compound_pages =
> -		(1<<compound_order(page)) * XEN_PFN_PER_PAGE;
> -	bool local = (page_pfn <= dev_pfn) &&
> -		(dev_pfn - page_pfn < compound_pages);
> -
> -	if (local)
> -		dma_direct_map_page(hwdev, page, offset, size, dir, attrs);
> -	else
> -		__xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
> -}
> -
> -static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
> -		size_t size, enum dma_data_direction dir, unsigned long attrs)
> -{
> -	unsigned long pfn = PFN_DOWN(handle);
> -	/*
> -	 * Dom0 is mapped 1:1, while the Linux page can be spanned accross
> -	 * multiple Xen page, it's not possible to have a mix of local and
> -	 * foreign Xen page. Dom0 is mapped 1:1, so calling pfn_valid on a
> -	 * foreign mfn will always return false. If the page is local we can
> -	 * safely call the native dma_ops function, otherwise we call the xen
> -	 * specific function.
> -	 */
> -	if (pfn_valid(pfn))
> -		dma_direct_unmap_page(hwdev, handle, size, dir, attrs);
> -	else
> -		__xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
> -}
> -
> -#endif /* _ASM_ARM64_XEN_PAGE_COHERENT_H */
> diff --git a/include/xen/arm/page-coherent.h b/include/xen/arm/page-coherent.h
> index 2ca9164a79bf..a840d6949a87 100644
> --- a/include/xen/arm/page-coherent.h
> +++ b/include/xen/arm/page-coherent.h
> @@ -2,6 +2,9 @@
>  #ifndef _XEN_ARM_PAGE_COHERENT_H
>  #define _XEN_ARM_PAGE_COHERENT_H
>  
> +#include <linux/dma-mapping.h>
> +#include <asm/page.h>
> +
>  void __xen_dma_map_page(struct device *hwdev, struct page *page,
>  	     dma_addr_t dev_addr, unsigned long offset, size_t size,
>  	     enum dma_data_direction dir, unsigned long attrs);
> @@ -13,4 +16,81 @@ void __xen_dma_sync_single_for_cpu(struct device *hwdev,
>  void __xen_dma_sync_single_for_device(struct device *hwdev,
>  		dma_addr_t handle, size_t size, enum dma_data_direction dir);
>  
> +static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
> +		dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs)
> +{
> +	return dma_direct_alloc(hwdev, size, dma_handle, flags, attrs);
> +}
> +
> +static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
> +		void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs)
> +{
> +	dma_direct_free(hwdev, size, cpu_addr, dma_handle, attrs);
> +}
> +
> +static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
> +		dma_addr_t handle, size_t size, enum dma_data_direction dir)
> +{
> +	unsigned long pfn = PFN_DOWN(handle);
> +
> +	if (pfn_valid(pfn))
> +		dma_direct_sync_single_for_cpu(hwdev, handle, size, dir);
> +	else
> +		__xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
> +}
> +
> +static inline void xen_dma_sync_single_for_device(struct device *hwdev,
> +		dma_addr_t handle, size_t size, enum dma_data_direction dir)
> +{
> +	unsigned long pfn = PFN_DOWN(handle);
> +	if (pfn_valid(pfn))
> +		dma_direct_sync_single_for_device(hwdev, handle, size, dir);
> +	else
> +		__xen_dma_sync_single_for_device(hwdev, handle, size, dir);
> +}
> +
> +static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
> +	     dma_addr_t dev_addr, unsigned long offset, size_t size,
> +	     enum dma_data_direction dir, unsigned long attrs)
> +{
> +	unsigned long page_pfn = page_to_xen_pfn(page);
> +	unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr);
> +	unsigned long compound_pages =
> +		(1<<compound_order(page)) * XEN_PFN_PER_PAGE;
> +	bool local = (page_pfn <= dev_pfn) &&
> +		(dev_pfn - page_pfn < compound_pages);
> +
> +	/*
> +	 * Dom0 is mapped 1:1, while the Linux page can span across
> +	 * multiple Xen pages, it's not possible for it to contain a
> +	 * mix of local and foreign Xen pages. So if the first xen_pfn
> +	 * == mfn the page is local otherwise it's a foreign page
> +	 * grant-mapped in dom0. If the page is local we can safely
> +	 * call the native dma_ops function, otherwise we call the xen
> +	 * specific function.
> +	 */
> +	if (local)
> +		dma_direct_map_page(hwdev, page, offset, size, dir, attrs);
> +	else
> +		__xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
> +}
> +
> +static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
> +		size_t size, enum dma_data_direction dir, unsigned long attrs)
> +{
> +	unsigned long pfn = PFN_DOWN(handle);
> +	/*
> +	 * Dom0 is mapped 1:1, while the Linux page can be spanned accross
> +	 * multiple Xen page, it's not possible to have a mix of local and
> +	 * foreign Xen page. Dom0 is mapped 1:1, so calling pfn_valid on a
> +	 * foreign mfn will always return false. If the page is local we can
> +	 * safely call the native dma_ops function, otherwise we call the xen
> +	 * specific function.
> +	 */
> +	if (pfn_valid(pfn))
> +		dma_direct_unmap_page(hwdev, handle, size, dir, attrs);
> +	else
> +		__xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
> +}
> +
>  #endif /* _XEN_ARM_PAGE_COHERENT_H */
> -- 
> 2.20.1
>