restore err = 0

fix transfer_len for reading as well. I think eliminate a need of delay

o Consider amount of bytes already transferred
o Add a small delay (not sure why it is needed, maybe another bug)

Add ()

Use broken-cd property

remove unused headers

fix copyrights as code was copy-pasted partially from work by andy

add pinit/release prototypes

Fix comment

so this won't work when CPU page size and IOMMU page sizes are different

In D29731#667264, @markj wrote:

Can you provide any pointers to docs or driver code that illustrates how the functions are used?

asserts added

Rename pmap_genter/gremove to pmap_gpu_enter/remove

cast vm_offset_t to dcache_wb

no need to invalidate ptes just write-back

I also added SMP support to Unleashed board. But that may not be notable change :)

Sadly but this failed testing even if I put DELAY(100).
I'll need to find out which request failed exactly.

Booted fine. All my PCI cards work fine.

o Place IOMMU to exact place where ACPI_DMAR was
o Remove IOMMU from i386/MINIMAL as we don't have it in i386/GENERIC

Remove unused headers

More style fixes:
o Rename header protection variables
o Make variables consistent:

struct smmu_unit is unit
struct smmu_domain is domain
struct smmu_ctx is ctx
struct iommu_unit is iommu
struct iommu_domain is iodom
struct iommu_ctx is ioctx

o Add locking around smmu_ctx_lookup() method
o ctx_free and domain_free methods return void
o Call to iommu_gas_fini_domain() and iommu_domain_fini() on domain deinitialization (iommu_domain_free())

Fix indentation

Address mmel's comments.

Rework the arm64 iommu interface so it could be used on other IOMMU engines in arm64 world, not only SMMU.
(Requested by mmel)

update copyright for smmu_quircks.c

Manage resident count for L3 pages of SMMU pmap

Set domain.end address (max guest addr + 1) to the VM_MAXUSER_ADDR

Fix comment

Rename iommu_smmu.c to smmu_iommu.c

The final patch to review

Address markj@ queries

Add default implementations of iommu_init/deinit

gicv3_iommu_deinit() added

o Check if entry is not NULL, otherwise return early
o Remove gicv3_its.c changes from this diff. They are moved to https://reviews.freebsd.org/D26878

Move iommu stubs to subr_bus_dma.c

In D26887#599735, @andrew wrote:

Would it make sense to move these to subr_bus_dma.c in the non-IOMMU case?

o Rename pmap_sremove_all() to pmap_sremove_pages()
o Remove unneeded check for L2_BLOCK in pmap_sremove_pages()