iommu/dma: Allow a single FQ in addition to per-CPU FQs

In some virtualized environments, including s390 paged memory guests,
IOTLB flushes are used to update IOMMU shadow tables. Due to this, they
are much more expensive than in typical bare metal environments or
non-paged s390 guests. In addition they may parallelize poorly in
virtualized environments. This changes the trade off for flushing IOVAs
such that minimizing the number of IOTLB flushes trumps any benefit of
cheaper queuing operations or increased paralellism.

In this scenario per-CPU flush queues pose several problems. Firstly
per-CPU memory is often quite limited prohibiting larger queues.
Secondly collecting IOVAs per-CPU but flushing via a global timeout
reduces the number of IOVAs flushed for each timeout especially on s390
where PCI interrupts may not be bound to a specific CPU.

Let's introduce a single flush queue mode that reuses the same queue
logic but only allocates a single global queue. This mode is selected by
dma-iommu if a newly introduced .shadow_on_flush flag is set in struct
dev_iommu. As a first user the s390 IOMMU driver sets this flag during
probe_device. With the unchanged small FQ size and timeouts this setting
is worse than per-CPU queues but a follow up patch will make the FQ size
and timeout variable. Together this allows the common IOVA flushing code
to more closely resemble the global flush behavior used on s390's
previous internal DMA API implementation.

Link: https://lore.kernel.org/all/9a466109-01c5-96b0-bf03-304123f435ee@arm.com/
Acked-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> #s390
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20230928-dma_iommu-v13-5-9e5fc4dacc36@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Disable deferred flush for ISM devices

ISM devices are virtual PCI devices used for cross-LPAR communication.
Unlike real PCI devices ISM devices do not use the hardware IOMMU but
inspects IOMMU translation tables directly on IOTLB flush (s390 RPCIT
instruction).

ISM devices keep their DMA allocations static and only very rarely DMA
unmap at all. For each IOTLB flush that occurs after unmap the ISM
devices will however inspect the area of the IOVA space indicated by the
flush. This means that for the global IOTLB flushes used by the flush
queue mechanism the entire IOVA space would be inspected. In principle
this would be fine, albeit potentially unnecessarily slow, it turns out
however that ISM devices are sensitive to seeing IOVA addresses that are
currently in use in the IOVA range being flushed. Seeing such in-use
IOVA addresses will cause the ISM device to enter an error state and
become unusable.

Fix this by claiming IOMMU_CAP_DEFERRED_FLUSH only for non-ISM devices.
This makes sure IOTLB flushes only cover IOVAs that have been unmapped
and also restricts the range of the IOTLB flush potentially reducing
latency spikes.

Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20230928-dma_iommu-v13-4-9e5fc4dacc36@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

s390/pci: Use dma-iommu layer

While s390 already has a standard IOMMU driver and previous changes have
added I/O TLB flushing operations this driver is currently only used for
user-space PCI access such as vfio-pci. For the DMA API s390 instead
utilizes its own implementation in arch/s390/pci/pci_dma.c which drives
the same hardware and shares some code but requires a complex and
fragile hand over between DMA API and IOMMU API use of a device and
despite code sharing still leads to significant duplication and
maintenance effort. Let's utilize the common code DMAP API
implementation from drivers/iommu/dma-iommu.c instead allowing us to
get rid of arch/s390/pci/pci_dma.c.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20230928-dma_iommu-v13-3-9e5fc4dacc36@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Allow .iotlb_sync_map to fail and handle s390's -ENOMEM return

On s390 when using a paging hypervisor, .iotlb_sync_map is used to sync
mappings by letting the hypervisor inspect the synced IOVA range and
updating a shadow table. This however means that .iotlb_sync_map can
fail as the hypervisor may run out of resources while doing the sync.
This can be due to the hypervisor being unable to pin guest pages, due
to a limit on mapped addresses such as vfio_iommu_type1.dma_entry_limit
or lack of other resources. Either way such a failure to sync a mapping
should result in a DMA_MAPPING_ERROR.

Now especially when running with batched IOTLB flushes for unmap it may
be that some IOVAs have already been invalidated but not yet synced via
.iotlb_sync_map. Thus if the hypervisor indicates running out of
resources, first do a global flush allowing the hypervisor to free
resources associated with these mappings as well a retry creating the
new mappings and only if that also fails report this error to callers.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> # sun50i
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20230928-dma_iommu-v13-1-9e5fc4dacc36@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Convert remaining simple drivers to domain_alloc_paging()

These drivers don't support IOMMU_DOMAIN_DMA, so this commit effectively
allows them to support that mode.

The prior work to require default_domains makes this safe because every
one of these drivers is either compilation incompatible with dma-iommu.c,
or already establishing a default_domain. In both cases alloc_domain()
will never be called with IOMMU_DOMAIN_DMA for these drivers so it is safe
to drop the test.

Removing these tests clarifies that the domain allocation path is only
about the functionality of a paging domain and has nothing to do with
policy of how the paging domain is used for UNMANAGED/DMA/DMA_FQ.

Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Tested-by: Steven Price <steven.price@arm.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/24-v8-81230027b2fa+9d-iommu_all_defdom_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Add IOMMU_DOMAIN_PLATFORM for S390

The PLATFORM domain will be set as the default domain and attached as
normal during probe. The driver will ignore the initial attach from a NULL
domain to the PLATFORM domain.

After this, the PLATFORM domain's attach_dev will be called whenever we
detach from an UNMANAGED domain (eg for VFIO). This is the same time the
original design would have called op->detach_dev().

This is temporary until the S390 dma-iommu.c conversion is merged.

Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/4-v8-81230027b2fa+9d-iommu_all_defdom_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Use GFP_KERNEL in sleepable contexts

These contexts are sleepable, so use the proper annotation. The GFP_ATOMIC
was added mechanically in the prior patches.

Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/10-v3-76b587fe28df+6e3-iommu_map_gfp_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Push the gfp parameter to the kmem_cache_alloc()'s

dma_alloc_cpu_table() and dma_alloc_page_table() are eventually called by
iommufd through s390_iommu_map_pages() and it should not be forced to
atomic. Thread the gfp parameter through the call chain starting from
s390_iommu_map_pages().

Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/9-v3-76b587fe28df+6e3-iommu_map_gfp_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Add set_platform_dma_ops callbacks

For those IOMMU drivers that don't provide default domain support, add an
implementation of set_platform_dma_ops callback so that the IOMMU core
could return the DMA control to platform DMA ops. At the same time, with
the set_platform_dma_ops implemented, there is no need for detach_dev.
Remove it to avoid dead code.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20230110025408.667767-4-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

irq/s390: Add arch_is_isolated_msi() for s390

s390 doesn't use irq_domains, so it has no place to set
IRQ_DOMAIN_FLAG_ISOLATED_MSI. Instead of continuing to abuse the iommu
subsystem to convey this information add a simple define which s390 can
make statically true. The define will cause msi_device_has_isolated() to
return true.

Remove IOMMU_CAP_INTR_REMAP from the s390 iommu driver.

Link: https://lore.kernel.org/r/8-v3-3313bb5dd3a3+10f11-secure_msi_jgg@nvidia.com
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

s390/pci: use lock-free I/O translation updates

I/O translation tables on s390 use 8 byte page table entries and tables
which are allocated lazily but only freed when the entire I/O
translation table is torn down. Also each IOVA can at any time only
translate to one physical address Furthermore I/O table accesses by the
IOMMU hardware are cache coherent. With a bit of care we can thus use
atomic updates to manipulate the translation table without having to use
a global lock at all. This is done analogous to the existing I/O
translation table handling code used on Intel and AMD x86 systems.

Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20221109142903.4080275-6-schnelle@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Optimize IOMMU table walking

When invalidating existing table entries for unmap there is no need to
know the physical address beforehand so don't do an extra walk of the
IOMMU table to get it. Also when invalidating entries not finding an
entry indicates an invalid unmap and not a lack of memory we also don't
need to undo updates in this case. Implement this by splitting
s390_iommu_update_trans() in a variant for validating and one for
invalidating translations.

Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20221109142903.4080275-5-schnelle@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Use RCU to allow concurrent domain_list iteration

The s390_domain->devices list is only added to when new devices are
attached but is iterated through in read-only fashion for every mapping
operation as well as for I/O TLB flushes and thus in performance
critical code causing contention on the s390_domain->list_lock.
Fortunately such a read-mostly linked list is a standard use case for
RCU. This change closely follows the example fpr RCU protected list
given in Documentation/RCU/listRCU.rst.

Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20221109142903.4080275-4-schnelle@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Add I/O TLB ops

Currently s390-iommu does an I/O TLB flush (RPCIT) for every update of
the I/O translation table explicitly. For one this is wasteful since
RPCIT can be skipped after a mapping operation if zdev->tlb_refresh is
unset. Moreover we can do a single RPCIT for a range of pages including
whne doing lazy unmapping.

Thankfully both of these optimizations can be achieved by implementing
the IOMMU operations common code provides for the different types of I/O
tlb flushes:

* flush_iotlb_all: Flushes the I/O TLB for the entire IOVA space
* iotlb_sync: Flushes the I/O TLB for a range of pages that can be
gathered up, for example to implement lazy unmapping.
* iotlb_sync_map: Flushes the I/O TLB after a mapping operation

Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20221109142903.4080275-3-schnelle@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Make attach succeed even if the device is in error state

If a zPCI device is in the error state while switching IOMMU domains
zpci_register_ioat() will fail and we would end up with the device not
attached to any domain. In this state since zdev->dma_table == NULL
a reset via zpci_hot_reset_device() would wrongfully re-initialize the
device for DMA API usage using zpci_dma_init_device(). As automatic
recovery is currently disabled while attached to an IOMMU domain this
only affects slot resets triggered through other means but will affect
automatic recovery once we switch to using dma-iommu.

Additionally with that switch common code expects attaching to the
default domain to always work so zpci_register_ioat() should only fail
if there is no chance to recover anyway, e.g. if the device has been
unplugged.

Improve the robustness of attach by specifically looking at the status
returned by zpci_mod_fc() to determine if the device is unavailable and
in this case simply ignore the error. Once the device is reset
zpci_hot_reset_device() will then correctly set the domain's DMA
translation tables.

Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221109142903.4080275-2-schnelle@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Implement map_pages()/unmap_pages() instead of map()/unmap()

While s390-iommu currently implements the map_page()/unmap_page()
operations which only map/unmap a single page at a time the internal
s390_iommu_update_trans() API already supports mapping/unmapping a range
of pages at once. Take advantage of this by implementing the
map_pages()/unmap_pages() operations instead thus allowing users of the
IOMMU drivers to map multiple pages in a single call followed by
a single I/O TLB flush if needed.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20221025115657.1666860-7-schnelle@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Fix incorrect pgsize_bitmap

The .pgsize_bitmap property of struct iommu_ops is not a page mask but
rather has a bit set for each size of pages the IOMMU supports. As the
comment correctly pointed out at this moment the code only support 4K
pages so simply use SZ_4K here.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20221025115657.1666860-6-schnelle@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Fix incorrect aperture check

The domain->geometry.aperture_end specifies the last valid address treat
it as such when checking if a DMA address is valid.

Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20221025115657.1666860-5-schnelle@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Fix potential s390_domain aperture shrinking

The s390 IOMMU driver currently sets the IOMMU domain's aperture to
match the device specific DMA address range of the device that is first
attached. This is not ideal. For one if the domain has no device
attached in the meantime the aperture could be shrunk allowing
translations outside the aperture to exist in the translation tables.
Also this is a bit of a misuse of the aperture which really should
describe what addresses can be translated and not some device specific
limitations.

Instead of misusing the aperture like this we can instead create
reserved ranges for the ranges inaccessible to the attached devices
allowing devices with overlapping ranges to still share an IOMMU domain.
This also significantly simplifies s390_iommu_attach_device() allowing
us to move the aperture check to the beginning of the function and
removing the need to hold the device list's lock to check the aperture.

As we then use the same aperture for all domains and it only depends on
the table properties we can already check zdev->start_dma/end_dma at
probe time and turn the check on attach into a WARN_ON().

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20221025115657.1666860-4-schnelle@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Get rid of s390_domain_device

The struct s390_domain_device serves the sole purpose as list entry for
the devices list of a struct s390_domain. As it contains no additional
information besides a list_head and a pointer to the struct zpci_dev we
can simplify things and just thread the device list through struct
zpci_dev directly. This removes the need to allocate during domain
attach and gets rid of one level of indirection during mapping
operations.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20221025115657.1666860-3-schnelle@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Fix duplicate domain attachments

Since commit fa7e9ecc5e1c ("iommu/s390: Tolerate repeat attach_dev
calls") we can end up with duplicates in the list of devices attached to
a domain. This is inefficient and confusing since only one domain can
actually be in control of the IOMMU translations for a device. Fix this
by detaching the device from the previous domain, if any, on attach.
Add a WARN_ON() in case we still have attached devices on freeing the
domain. While here remove the re-attach on failure dance as it was
determined to be unlikely to help and may confuse debug and recovery.

Fixes: fa7e9ecc5e1c ("iommu/s390: Tolerate repeat attach_dev calls")
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20221025115657.1666860-2-schnelle@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Clean up bus_set_iommu()

Clean up the remaining trivial bus_set_iommu() callsites along
with the implementation. Now drivers only have to know and care
about iommu_device instances, phew!

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> # s390
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com> # s390
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/ea383d5f4d74ffe200ab61248e5de6e95846180a.1660572783.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Fail probe for non-PCI devices

s390-iommu only supports pci_bus_type today.

Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/8cb71ea1b24bd2622c1937bd9cfffe73b126eb56.1660572783.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Retire iommu_capable()

With all callers now converted to the device-specific version, retire
the old bus-based interface, and give drivers the chance to indicate
accurate per-instance capabilities.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/d8bd8777d06929ad8f49df7fc80e1b9af32a41b5.1660574547.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Tolerate repeat attach_dev calls

Since commit 0286300e6045 ("iommu: iommu_group_claim_dma_owner() must
always assign a domain") s390-iommu will get called to allocate multiple
unmanaged iommu domains for a vfio-pci device -- however the current
s390-iommu logic tolerates only one. Recognize that multiple domains can
be allocated and handle switching between DMA or different iommu domain
tables during attach_dev.

Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220519182929.581898-1-mjrosato@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Split struct iommu_ops

Move the domain specific operations out of struct iommu_ops into a new
structure that only has domain specific operations. This solves the
problem of needing to know if the method vector for a given operation
needs to be retrieved from the device or the domain. Logically the domain
ops are the ones that make sense for external subsystems and endpoint
drivers to use, while device ops, with the sole exception of domain_alloc,
are IOMMU API internals.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220216025249.3459465-10-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

s390/pci: use physical addresses in DMA tables

The entries in the DMA translation tables for our IOMMU must specify
physical addresses of either the next level table or the final page
to be mapped for DMA. Currently however the code simply passes the
virtual addresses of both. On the other hand we still need to walk the
tables via their virtual addresses so we need to do a phys_to_virt()
when setting the entries and a virt_to_phys() when getting them.
Similarly when passing the I/O translation anchor to the hardware we
must also specify its physical address.

As the DMA and IOMMU APIs we are implementing already use the correct
phys_addr_t type for the address to be mapped let's also thread this
through instead of treating it as just an unsigned long.

Note: this currently doesn't fix a real bug, since virtual addresses
are indentical to physical ones.

Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/pci: improve DMA translation init and exit

Currently zpci_dma_init_device()/zpci_dma_exit_device() is called as
part of zpci_enable_device()/zpci_disable_device() and errors for
zpci_dma_exit_device() are always ignored even if we could abort.

Improve upon this by moving zpci_dma_exit_device() out of
zpci_disable_device() and check for errors whenever we have a way to
abort the current operation. Note that for example in
zpci_event_hard_deconfigured() the device is expected to be gone so we
really can't abort and proceed even in case of error.

Similarly move the cc == 3 special case out of zpci_unregister_ioat()
and into the callers allowing to abort when finding an already disabled
devices precludes proceeding with the operation.

While we are at it log IOAT register/unregister errors in the s390
debugfs log,

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

iommu: Streamline registration interface

Rather than have separate opaque setter functions that are easy to
overlook and lead to repetitive boilerplate in drivers, let's pass the
relevant initialisation parameters directly to iommu_device_register().

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/ab001b87c533b6f4db71eb90db6f888953986c36.1617285386.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Convert to probe/release_device() call-backs

Convert the S390 IOMMU driver to use the probe_device() and
release_device() call-backs of iommu_ops, so that the iommu core code
does the group and sysfs setup.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20200429133712.31431-20-joro@8bytes.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

s390/pci: adaptation of iommu to multifunction

In the future the bus sysdata may not directly point to the
zpci_dev.

In preparation of upcoming patches let us abstract the
access to the zpci_dev from the device inside the pci device.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

iommu: Add gfp parameter to iommu_ops::map

Add a gfp_t parameter to the iommu_ops::map function.
Remove the needless locking in the AMD iommu driver.

The iommu_ops::map function (or the iommu_map function which calls it)
was always supposed to be sleepable (according to Joerg's comment in
this thread: https://lore.kernel.org/patchwork/patch/977520/ ) and so
should probably have had a "might_sleep()" since it was written. However
currently the dma-iommu api can call iommu_map in an atomic context,
which it shouldn't do. This doesn't cause any problems because any iommu
driver which uses the dma-iommu api uses gfp_atomic in it's
iommu_ops::map function. But doing this wastes the memory allocators
atomic pools.

Signed-off-by: Tom Murphy <murphyt7@tcd.ie>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Pass struct iommu_iotlb_gather to ->unmap() and ->iotlb_sync()

To allow IOMMU drivers to batch up TLB flushing operations and postpone
them until ->iotlb_sync() is called, extend the prototypes for the
->unmap() and ->iotlb_sync() IOMMU ops callbacks to take a pointer to
the current iommu_iotlb_gather structure.

All affected IOMMU drivers are updated, but there should be no
functional change since the extra parameter is ignored for now.

Signed-off-by: Will Deacon <will@kernel.org>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iommu/s390: Constify iommu_ops

iommu_ops are not supposed to change at runtime.
Functions 'bus_set_iommu' working with const iommu_ops provided
by <linux/iommu.h>. So mark the non-const structs as const.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Add support for iommu_device handling

Add support for the iommu_device_register interface to make
the s390 hardware iommus visible to the iommu core and in
sysfs.

Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Use iommu_group_get_for_dev() in s390_iommu_add_device()

The iommu_group_get_for_dev() function also attaches the
device to its group, so this code doesn't need to be in the
iommu driver.

Further by using this function the driver can make use of
default domains in the future.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: Drop duplicate header pci.h

Drop duplicate header pci.h from s390-iommu.c.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/s390: simplify registration of I/O address translation parameters

When a new function is attached to an iommu domain we need to register
I/O address translation parameters. Since commit
69eea95c ("s390/pci_dma: fix DMA table corruption with > 4 TB main memory")
start_dma and end_dma correctly describe the range of usable I/O addresses.

Simplify the code by using these values directly.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

iommu/s390: Fix sparse warnings

Fix these warnings:
CHECK drivers/iommu/s390-iommu.c
drivers/iommu/s390-iommu.c:52:21: warning: symbol 's390_domain_alloc' was not declared. Should it be static?
drivers/iommu/s390-iommu.c:76:6: warning: symbol 's390_domain_free' was not declared. Should it be static?

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

s390/pci_dma: handle dma table failures

We use lazy allocation for translation table entries but don't handle
allocation (and other) failures during translation table updates.

Handle these failures and undo translation table updates when it's
meaningful.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

iommu/s390: Add iommu api for s390 pci devices

This adds an IOMMU API implementation for s390 PCI devices.

Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>