[Freedreno] [PATCH v2 5/5] drm/msm: switch msm_kms_init_aspace() to use device_iommu_mapped()

[Robin Murphy]

On 2022-05-05 01:16, Dmitry Baryshkov wrote:
> Change msm_kms_init_aspace() to use generic function
> device_iommu_mapped() instead of the fwnode-specific interface
> dev_iommu_fwspec_get(). While we are at it, stop referencing
> platform_bus_type directly and use the bus of the IOMMU device.

FWIW, I'd have squashed these changes across the previous patches, such 
that the dodgy fwspec calls are never introduced in the first place, but 
it's your driver, and if that's the way you want to work it and Rob's 
happy with it too, then fine by me.

For the end result,

Reviewed-by: Robin Murphy <robin.murphy at arm.com>

I'm guessing MDP4 could probably use msm_kms_init_aspace() now as well, 
but unless there's any other reason to respin this series, that's 
something we could do as a follow-up. Thanks for sorting this out!

Robin.

> Suggested-by: Robin Murphy <robin.murphy at arm.com>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> ---
>   drivers/gpu/drm/msm/msm_drv.c | 14 +++++++-------
>   1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 98ae0036ab57..2fc3f820cd59 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -272,21 +272,21 @@ struct msm_gem_address_space *msm_kms_init_aspace(struct drm_device *dev)
>   	struct device *mdss_dev = mdp_dev->parent;
>   	struct device *iommu_dev;
>   
> -	domain = iommu_domain_alloc(&platform_bus_type);
> -	if (!domain) {
> -		drm_info(dev, "no IOMMU, fallback to phys contig buffers for scanout\n");
> -		return NULL;
> -	}
> -
>   	/*
>   	 * IOMMUs can be a part of MDSS device tree binding, or the
>   	 * MDP/DPU device.
>   	 */
> -	if (dev_iommu_fwspec_get(mdp_dev))
> +	if (device_iommu_mapped(mdp_dev))
>   		iommu_dev = mdp_dev;
>   	else
>   		iommu_dev = mdss_dev;
>   
> +	domain = iommu_domain_alloc(iommu_dev->bus);
> +	if (!domain) {
> +		drm_info(dev, "no IOMMU, fallback to phys contig buffers for scanout\n");
> +		return NULL;
> +	}
> +
>   	mmu = msm_iommu_new(iommu_dev, domain);
>   	if (IS_ERR(mmu)) {
>   		iommu_domain_free(domain);