iommu/amd: Simplify build_inv_address()

This function is doing more work than it needs to:

 - iommu_num_pages() is pointless, the fls() is going to compute the
   required page size already.

 - It is easier to understand as sz_lg2, which is 12 if size is 4K,
   than msb_diff which is 11 if size is 4K.

 - Simplify the control flow to early exit on the out of range cases.

 - Use the usual last instead of end to signify an inclusive last
   address.

 - Use GENMASK to compute the 1's mask.

 - Use GENMASK to compute the address mask for the command layout,
   not PAGE_MASK.

 - Directly reference the spec language that defines the 52 bit
   limit.

No functional change intended.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Wei Wang <wei.w.wang@hotmail.com>
Tested-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

0 files changed, 0 insertions, 0 deletions