linux-kernel - Re: [PATCH v7 19/21] iommu/mediatek: Rename enable_4GB to dram_is

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Message-ID: <9bf13c22-0c73-2950-2204-23d577976b03@gmail.com>
Date:   Tue, 18 Jun 2019 18:06:47 +0200
From:   Matthias Brugger <matthias.bgg@...il.com>
To:     Yong Wu <yong.wu@...iatek.com>, Joerg Roedel <joro@...tes.org>,
        Robin Murphy <robin.murphy@....com>,
        Rob Herring <robh+dt@...nel.org>
Cc:     Evan Green <evgreen@...omium.org>, Tomasz Figa <tfiga@...gle.com>,
        Will Deacon <will.deacon@....com>,
        linux-mediatek@...ts.infradead.org, srv_heupstream@...iatek.com,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        iommu@...ts.linux-foundation.org, yingjoe.chen@...iatek.com,
        youlin.pei@...iatek.com, Nicolas Boichat <drinkcat@...omium.org>,
        anan.sun@...iatek.com, Matthias Kaehlcke <mka@...omium.org>
Subject: Re: [PATCH v7 19/21] iommu/mediatek: Rename enable_4GB to dram_is_4gb



On 10/06/2019 14:17, Yong Wu wrote:
> This patch only rename the variable name from enable_4GB to
> dram_is_4gb for readable.

>From my understanding this is true when available RAM > 4GB so I think the name
should be something like dram_bigger_4gb otherwise it may create confusion again.

Also from my point of view this patch should be done before
"[PATCH 06/21] iommu/io-pgtable-arm-v7s: Extend MediaTek 4GB Mode"

Regards,
Matthias

> 
> Signed-off-by: Yong Wu <yong.wu@...iatek.com>
> Reviewed-by: Evan Green <evgreen@...omium.org>
> ---
>  drivers/iommu/mtk_iommu.c | 10 +++++-----
>  drivers/iommu/mtk_iommu.h |  2 +-
>  2 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index 86158d8..67cab2d 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -382,7 +382,7 @@ static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova,
>  	int ret;
>  
>  	/* The "4GB mode" M4U physically can not use the lower remap of Dram. */
> -	if (data->plat_data->has_4gb_mode && data->enable_4GB)
> +	if (data->plat_data->has_4gb_mode && data->dram_is_4gb)
>  		paddr |= BIT_ULL(32);
>  
>  	spin_lock_irqsave(&dom->pgtlock, flags);
> @@ -554,13 +554,13 @@ static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
>  	writel_relaxed(regval, data->base + REG_MMU_INT_MAIN_CONTROL);
>  
>  	if (data->plat_data->m4u_plat == M4U_MT8173)
> -		regval = (data->protect_base >> 1) | (data->enable_4GB << 31);
> +		regval = (data->protect_base >> 1) | (data->dram_is_4gb << 31);
>  	else
>  		regval = lower_32_bits(data->protect_base) |
>  			 upper_32_bits(data->protect_base);
>  	writel_relaxed(regval, data->base + REG_MMU_IVRP_PADDR);
>  
> -	if (data->enable_4GB && data->plat_data->has_vld_pa_rng) {
> +	if (data->dram_is_4gb && data->plat_data->has_vld_pa_rng) {
>  		/*
>  		 * If 4GB mode is enabled, the validate PA range is from
>  		 * 0x1_0000_0000 to 0x1_ffff_ffff. here record bit[32:30].
> @@ -611,8 +611,8 @@ static int mtk_iommu_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
>  
> -	/* Whether the current dram is over 4GB */
> -	data->enable_4GB = !!(max_pfn > (BIT_ULL(32) >> PAGE_SHIFT));
> +	/* Whether the current dram is 4GB. */
> +	data->dram_is_4gb = !!(max_pfn > (BIT_ULL(32) >> PAGE_SHIFT));
>  
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	data->base = devm_ioremap_resource(dev, res);
> diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
> index 753266b..e8114b2 100644
> --- a/drivers/iommu/mtk_iommu.h
> +++ b/drivers/iommu/mtk_iommu.h
> @@ -65,7 +65,7 @@ struct mtk_iommu_data {
>  	struct mtk_iommu_domain		*m4u_dom;
>  	struct iommu_group		*m4u_group;
>  	struct mtk_smi_iommu		smi_imu;      /* SMI larb iommu info */
> -	bool                            enable_4GB;
> +	bool                            dram_is_4gb;
>  	bool				tlb_flush_active;
>  
>  	struct iommu_device		iommu;
>