> From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> Sent: Thursday, July 13, 2023 12:33 PM
>
> @@ -409,6 +409,7 @@ struct iommu_fault_param {
> * @priv: IOMMU Driver private data
> * @max_pasids: number of PASIDs this device can consume
> * @attach_deferred: the dma domain attachment is deferred
> + * @requires_direct: The driver requested IOMMU_RESV_DIRECT
it's not accurate to say "driver requested" as it's a device attribute.
s/requires_direct/require_direct/
what about "has_resv_direct"?
> @@ -959,14 +959,12 @@ static int
> iommu_create_device_direct_mappings(struct iommu_domain *domain,
> unsigned long pg_size;
> int ret = 0;
>
> - if (!iommu_is_dma_domain(domain))
> - return 0;
> -
> - BUG_ON(!domain->pgsize_bitmap);
> -
> - pg_size = 1UL << __ffs(domain->pgsize_bitmap);
> + pg_size = domain->pgsize_bitmap ? 1UL << __ffs(domain-
> >pgsize_bitmap) : 0;
> INIT_LIST_HEAD(&mappings);
>
> + if (WARN_ON_ONCE(iommu_is_dma_domain(domain) && !pg_size))
> + return -EINVAL;
> +
> iommu_get_resv_regions(dev, &mappings);
>
> /* We need to consider overlapping regions for different devices */
> @@ -974,13 +972,17 @@ static int
> iommu_create_device_direct_mappings(struct iommu_domain *domain,
> dma_addr_t start, end, addr;
> size_t map_size = 0;
>
> + if (entry->type == IOMMU_RESV_DIRECT)
> + dev->iommu->requires_direct = 1;
> +
> + if ((entry->type != IOMMU_RESV_DIRECT &&
> + entry->type != IOMMU_RESV_DIRECT_RELAXABLE) ||
> + !iommu_is_dma_domain(domain))
> + continue;
> +
> start = ALIGN(entry->start, pg_size);
> end = ALIGN(entry->start + entry->length, pg_size);
>
> - if (entry->type != IOMMU_RESV_DIRECT &&
> - entry->type != IOMMU_RESV_DIRECT_RELAXABLE)
> - continue;
> -
> for (addr = start; addr <= end; addr += pg_size) {
> phys_addr_t phys_addr;
>
piggybacking a device attribute detection in a function which tries to
populate domain mappings is a bit confusing.
Does it work better to introduce a new function to detect this attribute
and has it directly called in the probe path?
> @@ -2121,6 +2123,21 @@ static int __iommu_device_set_domain(struct
> iommu_group *group,
> {
> int ret;
>
> + /*
> + * If the driver has requested IOMMU_RESV_DIRECT then we cannot
ditto. It's not requested by the driver.
> allow
> + * the blocking domain to be attached as it does not contain the
> + * required 1:1 mapping. This test effectively exclusive the device
s/exclusive/excludes/
