Re: [PATCH v9 2/3] iommu/mediatek: Rename MTK_IOMMU_TLB_ADDR to MTK_IOMMU_ADDR

From: <yf.wang@mediatek.com>
To: <robin.murphy@arm.com>
Cc: <Libo.Kang@mediatek.com>, <iommu@lists.linux-foundation.org>,
	<joro@8bytes.org>, <linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	<linux-mediatek@lists.infradead.org>, <matthias.bgg@gmail.com>,
	<miles.chen@mediatek.com>, <ning.li@mediatek.com>,
	<will@kernel.org>, <wsd_upstream@mediatek.com>,
	<yf.wang@mediatek.com>, <yong.wu@mediatek.com>
Subject: Re: [PATCH v9 2/3] iommu/mediatek: Rename MTK_IOMMU_TLB_ADDR to MTK_IOMMU_ADDR
Date: Thu, 16 Jun 2022 14:40:24 +0800	[thread overview]
Message-ID: <20220616064024.10683-1-yf.wang@mediatek.com> (raw)
In-Reply-To: <949c22c4-5f64-47cf-673c-14fcadcc1d27@arm.com>

On Wed, 2022-06-15 at 18:14 +0100, Robin Murphy wrote:
> On 2022-06-15 17:12, yf.wang--- via iommu wrote:
> > From: Yunfei Wang <yf.wang@mediatek.com>
> > 
> > Rename MTK_IOMMU_TLB_ADDR to MTK_IOMMU_ADDR, and update
> > MTK_IOMMU_ADDR
> > definition for better generality.
> > 
> > Signed-off-by: Ning Li <ning.li@mediatek.com>
> > Signed-off-by: Yunfei Wang <yf.wang@mediatek.com>
> > ---
> >   drivers/iommu/mtk_iommu.c | 8 ++++----
> >   1 file changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> > index bb9dd92c9898..3d62399e8865 100644
> > --- a/drivers/iommu/mtk_iommu.c
> > +++ b/drivers/iommu/mtk_iommu.c
> > @@ -265,8 +265,8 @@ static const struct iommu_ops mtk_iommu_ops;
> >   
> >   static int mtk_iommu_hw_init(const struct mtk_iommu_data *data,
> > unsigned int bankid);
> >   
> > -#define MTK_IOMMU_TLB_ADDR(iova) ({				
> > 	\
> > -	dma_addr_t _addr = iova;					\
> > +#define MTK_IOMMU_ADDR(addr) ({					
> > 	\
> > +	unsigned long long _addr = addr;				\
> 
> If phys_addr_t is 64-bit, then dma_addr_t is also 64-bit, so there is
> no 
> loss of generality from using an appropriate type - IOVAs have to
> fit 
> into dma_addr_t for iommu-dma, after all. However, since IOVAs also
> have 
> to fit into unsigned long in the general IOMMU API, as "addr" is
> here, 
> then this is still just as broken for 32-bit LPAE as the existing
> code is.
> 
> Thanks,
> Robin.
> 

Hi Robin,
According to Path#1's suggestion, next version will keep ttbr to encoded 32 bits,
then will don't need to modify it.

Thanks,
Yunfei.

> >   	((lower_32_bits(_addr) & GENMASK(31, 12)) |
> > upper_32_bits(_addr));\
> >   })
> >   
> > @@ -381,8 +381,8 @@ static void
> > mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size,
> >   		writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
> >   			       base + data->plat_data->inv_sel_reg);
> >   
> > -		writel_relaxed(MTK_IOMMU_TLB_ADDR(iova), base +
> > REG_MMU_INVLD_START_A);
> > -		writel_relaxed(MTK_IOMMU_TLB_ADDR(iova + size - 1),
> > +		writel_relaxed(MTK_IOMMU_ADDR(iova), base +
> > REG_MMU_INVLD_START_A);
> > +		writel_relaxed(MTK_IOMMU_ADDR(iova + size - 1),
> >   			       base + REG_MMU_INVLD_END_A);
> >   		writel_relaxed(F_MMU_INV_RANGE, base +
> > REG_MMU_INVALIDATE);
> >