[PATCH v10 09/23] iommu/io-pgtable-arm-v7s: Extend to support PA[33:32] for MediaTek

Will Deacon will at kernel.org
Wed Aug 21 08:24:49 PDT 2019


On Wed, Aug 21, 2019 at 09:53:12PM +0800, Yong Wu wrote:
> MediaTek extend the arm v7s descriptor to support up to 34 bits PA where
> the bit32 and bit33 are encoded in the bit9 and bit4 of the PTE
> respectively. Meanwhile the iova still is 32bits.
> 
> Regarding whether the pagetable address could be over 4GB, the mt8183
> support it while the previous mt8173 don't, thus keep it as is.
> 
> Signed-off-by: Yong Wu <yong.wu at mediatek.com>
> ---
>  drivers/iommu/io-pgtable-arm-v7s.c | 32 +++++++++++++++++++++++++-------
>  include/linux/io-pgtable.h         |  7 +++----
>  2 files changed, 28 insertions(+), 11 deletions(-)

[...]

> @@ -731,7 +747,9 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
>  {
>  	struct arm_v7s_io_pgtable *data;
>  
> -	if (cfg->ias > ARM_V7S_ADDR_BITS || cfg->oas > ARM_V7S_ADDR_BITS)
> +	if (cfg->ias > ARM_V7S_ADDR_BITS ||
> +	    (cfg->oas > ARM_V7S_ADDR_BITS &&
> +	     !(cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT)))

Please can you instead change arm_v7s_alloc_pgtable() so that it allows an
ias of up to 34 when the IO_PGTABLE_QUIRK_ARM_MTK_EXT is set?

With that change:

Acked-by: Will Deacon <will at kernel.org>

Will



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