[PATCH v5 08/25] iommu: Reorganize iommu_get_default_domain_type() to respect def_domain_type()

[Baolu Lu]

On 2023/7/25 1:21, Jason Gunthorpe wrote:
> Except for dart every driver returns 0 or IDENTITY from def_domain_type().
> 
> The drivers that return IDENTITY have some kind of good reason, typically
> that quirky hardware really can't support anything other than IDENTITY.
> 
> Arrange things so that if the driver says it needs IDENTITY then
> iommu_get_default_domain_type() either fails or returns IDENTITY.  It will
> never reject the driver's override to IDENTITY.
> 
> The only real functional difference is that the PCI untrusted flag is now
> ignored for quirky HW instead of overriding the IOMMU driver.
> 
> This makes the next patch cleaner that wants to force IDENTITY always for
> ARM_IOMMU because there is no support for DMA.
> 
> Tested-by: Steven Price<steven.price at arm.com>
> Tested-by: Marek Szyprowski<m.szyprowski at samsung.com>
> Tested-by: Nicolin Chen<nicolinc at nvidia.com>
> Signed-off-by: Jason Gunthorpe<jgg at nvidia.com>
> ---
>   drivers/iommu/iommu.c | 66 +++++++++++++++++++++----------------------
>   1 file changed, 33 insertions(+), 33 deletions(-)

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