Re: [PATCH v5 09/27] iommu/io-pgtable-arm-v7s: Extend PA34 for MediaTek

[Tomasz Figa]

On Wed, Dec 09, 2020 at 04:00:44PM +0800, Yong Wu wrote:
> MediaTek extend the bit5 in lvl1 and lvl2 descriptor as PA34.
> 
> Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> Acked-by: Will Deacon <will@xxxxxxxxxx>
> Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
> ---
>  drivers/iommu/io-pgtable-arm-v7s.c | 9 +++++++--
>  drivers/iommu/mtk_iommu.c          | 2 +-
>  include/linux/io-pgtable.h         | 4 ++--
>  3 files changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
> index e880745ab1e8..4d0aa079470f 100644
> --- a/drivers/iommu/io-pgtable-arm-v7s.c
> +++ b/drivers/iommu/io-pgtable-arm-v7s.c
> @@ -112,9 +112,10 @@
>  #define ARM_V7S_TEX_MASK		0x7
>  #define ARM_V7S_ATTR_TEX(val)		(((val) & ARM_V7S_TEX_MASK) << ARM_V7S_TEX_SHIFT)
>  
> -/* MediaTek extend the two bits for PA 32bit/33bit */
> +/* MediaTek extend the bits below for PA 32bit/33bit/34bit */
>  #define ARM_V7S_ATTR_MTK_PA_BIT32	BIT(9)
>  #define ARM_V7S_ATTR_MTK_PA_BIT33	BIT(4)
> +#define ARM_V7S_ATTR_MTK_PA_BIT34	BIT(5)
>  
>  /* *well, except for TEX on level 2 large pages, of course :( */
>  #define ARM_V7S_CONT_PAGE_TEX_SHIFT	6
> @@ -194,6 +195,8 @@ static arm_v7s_iopte paddr_to_iopte(phys_addr_t paddr, int lvl,
>  		pte |= ARM_V7S_ATTR_MTK_PA_BIT32;
>  	if (paddr & BIT_ULL(33))
>  		pte |= ARM_V7S_ATTR_MTK_PA_BIT33;
> +	if (paddr & BIT_ULL(34))
> +		pte |= ARM_V7S_ATTR_MTK_PA_BIT34;
>  	return pte;
>  }
>  
> @@ -218,6 +221,8 @@ static phys_addr_t iopte_to_paddr(arm_v7s_iopte pte, int lvl,
>  		paddr |= BIT_ULL(32);
>  	if (pte & ARM_V7S_ATTR_MTK_PA_BIT33)
>  		paddr |= BIT_ULL(33);
> +	if (pte & ARM_V7S_ATTR_MTK_PA_BIT34)
> +		paddr |= BIT_ULL(34);
>  	return paddr;
>  }
>  
> @@ -754,7 +759,7 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
>  	if (cfg->ias > ARM_V7S_ADDR_BITS)
>  		return NULL;
>  
> -	if (cfg->oas > (arm_v7s_is_mtk_enabled(cfg) ? 34 : ARM_V7S_ADDR_BITS))
> +	if (cfg->oas > (arm_v7s_is_mtk_enabled(cfg) ? 35 : ARM_V7S_ADDR_BITS))
>  		return NULL;
>  
>  	if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS |
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index 6451d83753e1..ec3c87d4b172 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -320,7 +320,7 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom)
>  			IO_PGTABLE_QUIRK_ARM_MTK_EXT,
>  		.pgsize_bitmap = mtk_iommu_ops.pgsize_bitmap,
>  		.ias = 32,
> -		.oas = 34,
> +		.oas = 35,

Shouldn't this be set according to the real hardware capabilities,
instead of always setting it to 35?

Best regards,
Tomasz

>  		.tlb = &mtk_iommu_flush_ops,
>  		.iommu_dev = data->dev,
>  	};
> diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
> index 4cde111e425b..1ae0757f4f94 100644
> --- a/include/linux/io-pgtable.h
> +++ b/include/linux/io-pgtable.h
> @@ -77,8 +77,8 @@ struct io_pgtable_cfg {
>  	 *	TLB maintenance when mapping as well as when unmapping.
>  	 *
>  	 * IO_PGTABLE_QUIRK_ARM_MTK_EXT: (ARM v7s format) MediaTek IOMMUs extend
> -	 *	to support up to 34 bits PA where the bit32 and bit33 are
> -	 *	encoded in the bit9 and bit4 of the PTE respectively.
> +	 *	to support up to 35 bits PA where the bit32, bit33 and bit34 are
> +	 *	encoded in the bit9, bit4 and bit5 of the PTE respectively.
>  	 *
>  	 * IO_PGTABLE_QUIRK_NON_STRICT: Skip issuing synchronous leaf TLBIs
>  	 *	on unmap, for DMA domains using the flush queue mechanism for
> -- 
> 2.18.0
> 
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