[PATCH v4 4/6] iommu: Regulate EINVAL in ->attach_dev callback functions

[Baolu Lu]

On 9/21/22 4:23 PM, Nicolin Chen wrote:
> Following the new rules in include/linux/iommu.h kdocs, EINVAL now can be
> used to indicate that domain and device are incompatible by a caller that
> treats it as a soft failure and tries attaching to another domain.
> 
> On the other hand, there are ->attach_dev callback functions returning it
> for obvious device-specific errors. They will result in some inefficiency
> in the caller handling routine.
> 
> Update these places to corresponding errnos following the new rules.
> 
> Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>
> ---
>   drivers/iommu/fsl_pamu.c        | 2 +-
>   drivers/iommu/fsl_pamu_domain.c | 4 ++--
>   drivers/iommu/intel/pasid.c     | 6 ++++--
>   drivers/iommu/mtk_iommu.c       | 2 +-
>   drivers/iommu/omap-iommu.c      | 4 ++--
>   drivers/iommu/virtio-iommu.c    | 2 +-
>   6 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/iommu/fsl_pamu.c b/drivers/iommu/fsl_pamu.c
> index 0d03f837a5d4..2eb3211c8167 100644
> --- a/drivers/iommu/fsl_pamu.c
> +++ b/drivers/iommu/fsl_pamu.c
> @@ -211,7 +211,7 @@ int pamu_config_ppaace(int liodn, u32 omi, u32 stashid, int prot)
>   		ppaace->op_encode.index_ot.omi = omi;
>   	} else if (~omi != 0) {
>   		pr_debug("bad operation mapping index: %d\n", omi);
> -		return -EINVAL;
> +		return -ENODEV;
>   	}
>   
>   	/* configure stash id */
> diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
> index 011f9ab7f743..b4a1c0f79c3e 100644
> --- a/drivers/iommu/fsl_pamu_domain.c
> +++ b/drivers/iommu/fsl_pamu_domain.c
> @@ -258,7 +258,7 @@ static int fsl_pamu_attach_device(struct iommu_domain *domain,
>   	liodn = of_get_property(dev->of_node, "fsl,liodn", &len);
>   	if (!liodn) {
>   		pr_debug("missing fsl,liodn property at %pOF\n", dev->of_node);
> -		return -EINVAL;
> +		return -ENODEV;
>   	}
>   
>   	spin_lock_irqsave(&dma_domain->domain_lock, flags);
> @@ -267,7 +267,7 @@ static int fsl_pamu_attach_device(struct iommu_domain *domain,
>   		if (liodn[i] >= PAACE_NUMBER_ENTRIES) {
>   			pr_debug("Invalid liodn %d, attach device failed for %pOF\n",
>   				 liodn[i], dev->of_node);
> -			ret = -EINVAL;
> +			ret = -ENODEV;
>   			break;
>   		}
>   
> diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
> index c5e7e8b020a5..aff1a9caa496 100644
> --- a/drivers/iommu/intel/pasid.c
> +++ b/drivers/iommu/intel/pasid.c
> @@ -101,8 +101,10 @@ int intel_pasid_alloc_table(struct device *dev)
>   
>   	might_sleep();
>   	info = dev_iommu_priv_get(dev);
> -	if (WARN_ON(!info || !dev_is_pci(dev) || info->pasid_table))
> -		return -EINVAL;
> +	if (WARN_ON(!info || !dev_is_pci(dev)))
> +		return -ENODEV;
> +	if (WARN_ON(info->pasid_table))
> +		return -EEXIST;
>   
>   	pasid_table = kzalloc(sizeof(*pasid_table), GFP_KERNEL);
>   	if (!pasid_table)
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index 7e363b1f24df..be1a7d1cc630 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -607,7 +607,7 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom,
>   	dom->iop = alloc_io_pgtable_ops(ARM_V7S, &dom->cfg, data);
>   	if (!dom->iop) {
>   		dev_err(data->dev, "Failed to alloc io pgtable\n");
> -		return -EINVAL;
> +		return -ENOMEM;
>   	}
>   
>   	/* Update our support page sizes bitmap */
> diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
> index d9cf2820c02e..447e40d55918 100644
> --- a/drivers/iommu/omap-iommu.c
> +++ b/drivers/iommu/omap-iommu.c
> @@ -1414,7 +1414,7 @@ static int omap_iommu_attach_init(struct device *dev,
>   
>   	odomain->num_iommus = omap_iommu_count(dev);
>   	if (!odomain->num_iommus)
> -		return -EINVAL;
> +		return -ENODEV;
>   
>   	odomain->iommus = kcalloc(odomain->num_iommus, sizeof(*iommu),
>   				  GFP_ATOMIC);
> @@ -1464,7 +1464,7 @@ omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
>   
>   	if (!arch_data || !arch_data->iommu_dev) {
>   		dev_err(dev, "device doesn't have an associated iommu\n");
> -		return -EINVAL;
> +		return -ENODEV;
>   	}
>   
>   	spin_lock(&omap_domain->lock);
> diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
> index 80151176ba12..4c652773fd6c 100644
> --- a/drivers/iommu/virtio-iommu.c
> +++ b/drivers/iommu/virtio-iommu.c
> @@ -669,7 +669,7 @@ static int viommu_domain_finalise(struct viommu_endpoint *vdev,
>   		dev_err(vdev->dev,
>   			"granule 0x%lx larger than system page size 0x%lx\n",
>   			viommu_page_size, PAGE_SIZE);
> -		return -EINVAL;
> +		return -ENODEV;
>   	}
>   
>   	ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain,

For iommu/vt-d changes:

Reviewed-by: Lu Baolu <baolu.lu at linux.intel.com>

Best regards,
baolu