iommu/amd: Remove iommu_ignore_device()

The iommu_ignore_device() helper was historically called on device
initialization failure to clear the primary Device Table Entry (DTE) via
memset() and nullify the rlookup_table entry.

However, clearing the DTE on probe failure is problematic:
1. During normal boot, DTEs start out unconfigured (blocking DMA), making
   clearing redundant.
2. During kdump boot, pre-existing translations should be kept running
   until deferred attach rather than abruptly clearing them, which risks
   breaking in-flight transfers.
3. Writing to the DTE table via memset without flushing the hardware DTE
   cache risks aliasing & torn writes.
4. Clearing the rlookup_table entry breaks interrupt remapping for
   devices that fail probe or operate in translation-less modes.

Remove iommu_ignore_device() entirely and simplify the error return
paths in amd_iommu_probe_device().

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Suggested-by: Vasant Hegde <vasant.hegde@amd.com>
Reported-by: sashiko-bot@kernel.org
Closes: https://lore.kernel.org/all/20260529153216.2AD1E1F00899@smtp.kernel.org/
Signed-off-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

0 files changed, 0 insertions, 0 deletions