[PATCH v5 14/25] iommu/msm: Implement an IDENTITY domain

[Dmitry Baryshkov]

On 24/07/2023 20:22, Jason Gunthorpe wrote:
> What msm does during omap_iommu_set_platform_dma() is actually putting the

typo: msm driver doesn't use/provide omap_iommu_set_platform_dma().

> iommu into identity mode.
> 
> Move to the new core support for ARM_DMA_USE_IOMMU by defining
> ops->identity_domain.
> 
> This driver does not support IOMMU_DOMAIN_DMA, however it cannot be
> compiled on ARM64 either. Most likely it is fine to support dma-iommu.c
> 
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
> ---
>   drivers/iommu/msm_iommu.c | 23 +++++++++++++++++++----
>   1 file changed, 19 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
> index 79d89bad5132b7..26ed81cfeee897 100644
> --- a/drivers/iommu/msm_iommu.c
> +++ b/drivers/iommu/msm_iommu.c
> @@ -443,15 +443,20 @@ static int msm_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
>   	return ret;
>   }
>   
> -static void msm_iommu_set_platform_dma(struct device *dev)
> +static int msm_iommu_identity_attach(struct iommu_domain *identity_domain,
> +				     struct device *dev)
>   {
>   	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
> -	struct msm_priv *priv = to_msm_priv(domain);
> +	struct msm_priv *priv;
>   	unsigned long flags;
>   	struct msm_iommu_dev *iommu;
>   	struct msm_iommu_ctx_dev *master;
> -	int ret;
> +	int ret = 0;
>   
> +	if (domain == identity_domain || !domain)
> +		return 0;
> +
> +	priv = to_msm_priv(domain);
>   	free_io_pgtable_ops(priv->iop);
>   
>   	spin_lock_irqsave(&msm_iommu_lock, flags);
> @@ -468,8 +473,18 @@ static void msm_iommu_set_platform_dma(struct device *dev)
>   	}
>   fail:
>   	spin_unlock_irqrestore(&msm_iommu_lock, flags);
> +	return ret;
>   }
>   
> +static struct iommu_domain_ops msm_iommu_identity_ops = {
> +	.attach_dev = msm_iommu_identity_attach,
> +};
> +
> +static struct iommu_domain msm_iommu_identity_domain = {
> +	.type = IOMMU_DOMAIN_IDENTITY,
> +	.ops = &msm_iommu_identity_ops,
> +};
> +
>   static int msm_iommu_map(struct iommu_domain *domain, unsigned long iova,
>   			 phys_addr_t pa, size_t pgsize, size_t pgcount,
>   			 int prot, gfp_t gfp, size_t *mapped)
> @@ -675,10 +690,10 @@ irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id)
>   }
>   
>   static struct iommu_ops msm_iommu_ops = {
> +	.identity_domain = &msm_iommu_identity_domain,
>   	.domain_alloc = msm_iommu_domain_alloc,
>   	.probe_device = msm_iommu_probe_device,
>   	.device_group = generic_device_group,
> -	.set_platform_dma_ops = msm_iommu_set_platform_dma,
>   	.pgsize_bitmap = MSM_IOMMU_PGSIZES,
>   	.of_xlate = qcom_iommu_of_xlate,
>   	.default_domain_ops = &(const struct iommu_domain_ops) {

-- 
With best wishes
Dmitry