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Date:   Thu, 29 Aug 2019 15:42:10 -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>,
        x86@kernel.org, linux-arm-kernel@lists.infradead.org,
        xen-devel@lists.xenproject.org, iommu@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org, Julien Grall <julien.grall@arm.com>
Subject: Re: [PATCH 04/11] xen/arm: remove xen_dma_ops
In-Reply-To: <20190826121944.515-5-hch@lst.de>
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References: <20190826121944.515-1-hch@lst.de> <20190826121944.515-5-hch@lst.de>
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On Mon, 26 Aug 2019, Christoph Hellwig wrote:
> arm and arm64 can just use xen_swiotlb_dma_ops directly like x86, no
> need for a pointer indirection.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Julien Grall <julien.grall@arm.com>

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


> ---
>  arch/arm/mm/dma-mapping.c    | 3 ++-
>  arch/arm/xen/mm.c            | 4 ----
>  arch/arm64/mm/dma-mapping.c  | 3 ++-
>  include/xen/arm/hypervisor.h | 2 --
>  4 files changed, 4 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index 738097396445..2661cad36359 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -35,6 +35,7 @@
>  #include <asm/mach/map.h>
>  #include <asm/system_info.h>
>  #include <asm/dma-contiguous.h>
> +#include <xen/swiotlb-xen.h>
>  
>  #include "dma.h"
>  #include "mm.h"
> @@ -2360,7 +2361,7 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
>  
>  #ifdef CONFIG_XEN
>  	if (xen_initial_domain())
> -		dev->dma_ops = xen_dma_ops;
> +		dev->dma_ops = &xen_swiotlb_dma_ops;
>  #endif
>  	dev->archdata.dma_ops_setup = true;
>  }
> diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
> index 14210ebdea1a..9b3a6c0ca681 100644
> --- a/arch/arm/xen/mm.c
> +++ b/arch/arm/xen/mm.c
> @@ -163,16 +163,12 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order)
>  }
>  EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region);
>  
> -const struct dma_map_ops *xen_dma_ops;
> -EXPORT_SYMBOL(xen_dma_ops);
> -
>  int __init xen_mm_init(void)
>  {
>  	struct gnttab_cache_flush cflush;
>  	if (!xen_initial_domain())
>  		return 0;
>  	xen_swiotlb_init(1, false);
> -	xen_dma_ops = &xen_swiotlb_dma_ops;
>  
>  	cflush.op = 0;
>  	cflush.a.dev_bus_addr = 0;
> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
> index bd2b039f43a6..4b244a037349 100644
> --- a/arch/arm64/mm/dma-mapping.c
> +++ b/arch/arm64/mm/dma-mapping.c
> @@ -8,6 +8,7 @@
>  #include <linux/cache.h>
>  #include <linux/dma-noncoherent.h>
>  #include <linux/dma-iommu.h>
> +#include <xen/swiotlb-xen.h>
>  
>  #include <asm/cacheflush.h>
>  
> @@ -64,6 +65,6 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
>  
>  #ifdef CONFIG_XEN
>  	if (xen_initial_domain())
> -		dev->dma_ops = xen_dma_ops;
> +		dev->dma_ops = &xen_swiotlb_dma_ops;
>  #endif
>  }
> diff --git a/include/xen/arm/hypervisor.h b/include/xen/arm/hypervisor.h
> index 2982571f7cc1..43ef24dd030e 100644
> --- a/include/xen/arm/hypervisor.h
> +++ b/include/xen/arm/hypervisor.h
> @@ -19,8 +19,6 @@ static inline enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
>  	return PARAVIRT_LAZY_NONE;
>  }
>  
> -extern const struct dma_map_ops *xen_dma_ops;
> -
>  #ifdef CONFIG_XEN
>  void __init xen_early_init(void);
>  #else
> -- 
> 2.20.1
>