Re: [PATCH] iommu/arm-smmu-v3: Align size in __arm_smmu_tlb_inv_range

[Robin Murphy]

On 2022-04-13 05:17, Nicolin Chen wrote:
> To calculate num_pages, the size should be aligned with
> "page size", determined by the tg value. Otherwise, its
> following "while (iova < end)" might become an infinite
> loop if unaligned size is slightly greater than 1 << tg.

Hmm, how does a non-page-aligned invalidation request get generated in 
the first place?

Robin.

> Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
> ---
>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index 627a3ed5ee8f..8249dad5ae44 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -1879,7 +1879,7 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd,
>   		/* Determine what level the granule is at */
>   		cmd->tlbi.ttl = 4 - ((ilog2(granule) - 3) / (tg - 3));
>   
> -		num_pages = size >> tg;
> +		num_pages = ALIGN(size, 1 << tg) >> tg;
>   	}
>   
>   	cmds.num = 0;