linux-kernel - Re: [PATCH] iommu: Drop the of_iommu_{set/get}

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Message-ID: <c61db43c-82b1-b4c9-63cb-a8c78878cb39@arm.com>
Date:   Wed, 4 Jan 2017 15:11:35 +0000
From:   Robin Murphy <robin.murphy@....com>
To:     Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
        iommu@...ts.linux-foundation.org
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Matthias Brugger <matthias.bgg@...il.com>,
        Will Deacon <will.deacon@....com>,
        Joerg Roedel <joro@...tes.org>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        "yong.wu@...iatek.com" <yong.wu@...iatek.com>
Subject: Re: [PATCH] iommu: Drop the of_iommu_{set/get}_ops() interface

[+Yong Wu for mtk_iommu]

On 03/01/17 17:34, Lorenzo Pieralisi wrote:
> With the introduction of the new iommu_{register/get}_instance()
> interface in commit e4f10ffe4c9b ("iommu: Make of_iommu_set/get_ops() DT
> agnostic") (based on struct fwnode_handle as look-up token, so firmware
> agnostic) to register IOMMU instances with the core IOMMU layer there is
> no reason to keep the old OF based interface around any longer.
> 
> Convert all the IOMMU drivers (and OF IOMMU core code) that rely on the
> of_iommu_{set/get}_ops() to the new kernel interface to register/retrieve
> IOMMU instances and remove the of_iommu_{set/get}_ops() remaining glue
> code in order to complete the interface rework.

Reviewed-by: Robin Murphy <robin.murphy@....com>

Looking at before-and-after disassemblies, of_iommu.o is binary
identical, and exynos-iommu.o differs only in the use of dev->fwnode
rather than &dev->of_node->fwnode (and is binary identical if I hack it
back to the latter). I'm not sure why the (GCC 6.2) codegen for
mtk_iommu.o changes quite so much when merely replacing a callsite with
the contents of its static inline callee, but it does :/

Robin.

> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@....com>
> Cc: Matthias Brugger <matthias.bgg@...il.com>
> Cc: Will Deacon <will.deacon@....com>
> Cc: Robin Murphy <robin.murphy@....com>
> Cc: Joerg Roedel <joro@...tes.org>
> Cc: Marek Szyprowski <m.szyprowski@...sung.com>
> ---
> Exynos, msm and mtk code compile tested only owing to lack of
> test platforms, I would appreciate some help in testing this
> patch on those platforms before merging it even if it is just
> a simple interface conversion.
> 
> Thanks,
> Lorenzo
> 
>  drivers/iommu/exynos-iommu.c |  2 +-
>  drivers/iommu/msm_iommu.c    |  2 +-
>  drivers/iommu/mtk_iommu.c    |  2 +-
>  drivers/iommu/of_iommu.c     |  4 ++--
>  include/linux/of_iommu.h     | 11 -----------
>  5 files changed, 5 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> index 57ba0d3..b79e4c4 100644
> --- a/drivers/iommu/exynos-iommu.c
> +++ b/drivers/iommu/exynos-iommu.c
> @@ -628,7 +628,7 @@ static int __init exynos_sysmmu_probe(struct platform_device *pdev)
>  
>  	pm_runtime_enable(dev);
>  
> -	of_iommu_set_ops(dev->of_node, &exynos_iommu_ops);
> +	iommu_register_instance(dev->fwnode, &exynos_iommu_ops);
>  
>  	return 0;
>  }
> diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
> index b09692b..9cd3cee 100644
> --- a/drivers/iommu/msm_iommu.c
> +++ b/drivers/iommu/msm_iommu.c
> @@ -737,7 +737,7 @@ static int msm_iommu_probe(struct platform_device *pdev)
>  	}
>  
>  	list_add(&iommu->dev_node, &qcom_iommu_devices);
> -	of_iommu_set_ops(pdev->dev.of_node, &msm_iommu_ops);
> +	iommu_register_instance(pdev->dev.fwnode, &msm_iommu_ops);
>  
>  	pr_info("device mapped at %p, irq %d with %d ctx banks\n",
>  		iommu->base, iommu->irq, iommu->ncb);
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index 1479c76..0596ab2 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -655,7 +655,7 @@ static int mtk_iommu_init_fn(struct device_node *np)
>  		return ret;
>  	}
>  
> -	of_iommu_set_ops(np, &mtk_iommu_ops);
> +	iommu_register_instance(&np->fwnode, &mtk_iommu_ops);
>  	return 0;
>  }
>  
> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
> index 0f57ddc..d7f480a 100644
> --- a/drivers/iommu/of_iommu.c
> +++ b/drivers/iommu/of_iommu.c
> @@ -127,7 +127,7 @@ static const struct iommu_ops
>  			   "iommu-map-mask", &iommu_spec.np, iommu_spec.args))
>  		return NULL;
>  
> -	ops = of_iommu_get_ops(iommu_spec.np);
> +	ops = iommu_get_instance(&iommu_spec.np->fwnode);
>  	if (!ops || !ops->of_xlate ||
>  	    iommu_fwspec_init(&pdev->dev, &iommu_spec.np->fwnode, ops) ||
>  	    ops->of_xlate(&pdev->dev, &iommu_spec))
> @@ -157,7 +157,7 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
>  					   "#iommu-cells", idx,
>  					   &iommu_spec)) {
>  		np = iommu_spec.np;
> -		ops = of_iommu_get_ops(np);
> +		ops = iommu_get_instance(&np->fwnode);
>  
>  		if (!ops || !ops->of_xlate ||
>  		    iommu_fwspec_init(dev, &np->fwnode, ops) ||
> diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h
> index 6a7fc50..13394ac 100644
> --- a/include/linux/of_iommu.h
> +++ b/include/linux/of_iommu.h
> @@ -31,17 +31,6 @@ static inline const struct iommu_ops *of_iommu_configure(struct device *dev,
>  
>  #endif	/* CONFIG_OF_IOMMU */
>  
> -static inline void of_iommu_set_ops(struct device_node *np,
> -				    const struct iommu_ops *ops)
> -{
> -	iommu_register_instance(&np->fwnode, ops);
> -}
> -
> -static inline const struct iommu_ops *of_iommu_get_ops(struct device_node *np)
> -{
> -	return iommu_get_instance(&np->fwnode);
> -}
> -
>  extern struct of_device_id __iommu_of_table;
>  
>  typedef int (*of_iommu_init_fn)(struct device_node *);
>