When we iterate a master's config entries, what we generally care
about is the entry's stream map index, rather than the entry index
itself, so it's nice to have the iterator automatically assign the
former from the latter. Unfortunately, booting with KASAN reveals
the oversight that using a simple comma operator results in the
entry index being dereferenced before being checked for validity,
so we always access one element past the end of the fwspec array.

Flip things around so that the check always happens before the index
may be dereferenced.

Fixes: adfec2e7 ("iommu/arm-smmu: Convert to iommu_fwspec")
Reported-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

We seem to have forgotten to check that iommu_fwspecs actually belong to
us before we go ahead and dereference their private data. Oops.

Fixes: 021bb842 ("iommu/arm-smmu: Wire up generic configuration support")
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

The 32-bit ARM DMA configuration code predates the IOMMU core's default
domain functionality, and instead relies on allocating its own domains
and attaching any devices using the generic IOMMU binding to them.
Unfortunately, it does this relatively early on in the creation of the
device, before we've seen our add_device callback, which leads us to
attempt to operate on a half-configured master.

To avoid a crash, check for this situation on attach, but refuse to
play, as there's nothing we can do. This at least allows VFIO to keep
working for people who update their 32-bit DTs to the generic binding,
albeit with a few (innocuous) warnings from the DMA layer on boot.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

For non-aperture-based IOMMUs, the domain geometry seems to have become
the de-facto way of indicating the input address space size. That is
quite a useful thing from the users' perspective, so let's do the same.
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Tested-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

With everything else now in place, fill in an of_xlate callback and the
appropriate registration to plumb into the generic configuration
machinery, and watch everything just work.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

In the final step of preparation for full generic configuration support,
swap our fixed-size master_cfg for the generic iommu_fwspec. For the
legacy DT bindings, the driver simply gets to act as its own 'firmware'.
Farewell, arbitrary MAX_MASTER_STREAMIDS!
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Stream Match Registers are one of the more awkward parts of the SMMUv2
architecture; there are typically never enough to assign one to each
stream ID in the system, and configuring them such that a single ID
matches multiple entries is catastrophically bad - at best, every
transaction raises a global fault; at worst, they go *somewhere*.

To address the former issue, we can mask ID bits such that a single
register may be used to match multiple IDs belonging to the same device
or group, but doing so also heightens the risk of the latter problem
(which can be nasty to debug).

Tackle both problems at once by replacing the simple bitmap allocator
with something much cleverer. Now that we have convenient in-memory
representations of the stream mapping table, it becomes straightforward
to properly validate new SMR entries against the current state, opening
the door to arbitrary masking and SMR sharing.

Another feature which falls out of this is that with IDs shared by
separate devices being automatically accounted for, simply associating a
group pointer with the S2CR offers appropriate group allocation almost
for free, so hook that up in the process.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

We iterate over the SMEs associated with a master config quite a lot in
various places, and are about to do so even more. Let's wrap the idiom
in a handy iterator macro before the repetition gets out of hand.
Tested-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Simplify things somewhat by stashing our arm_smmu_device instance in
drvdata, so that it's readily available to our driver model callbacks.
Then we can excise the private list entirely, since the driver core
already has a perfectly good list of SMMU devices we can use in the one
instance we actually need to. Finally, make a further modest code saving
with the relatively new of_device_get_match_data() helper.
Tested-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

To be able to support the generic bindings and handle of_xlate() calls,
we need to be able to associate SMMUs and stream IDs directly with
devices *before* allocating IOMMU groups. Furthermore, to support real
default domains with multi-device groups we also have to handle domain
attach on a per-device basis, as the "whole group at a time" assumption
fails to properly handle subsequent devices added to a group after the
first has already triggered default domain creation and attachment.

To that end, use the now-vacant dev->archdata.iommu field for easy
config and SMMU instance lookup, and unify config management by chopping
down the platform-device-specific tree and probing the "mmu-masters"
property on-demand instead. This may add a bit of one-off overhead to
initially adding a new device, but we're about to deprecate that binding
in favour of the inherently-more-efficient generic ones anyway.

For the sake of simplicity, this patch does temporarily regress the case
of aliasing PCI devices by losing the duplicate stream ID detection that
the previous per-group config had. Stay tuned, because we'll be back to
fix that in a better and more general way momentarily...
Tested-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Making S2CRs first-class citizens within the driver with a high-level
representation of their state offers a neat solution to a few problems:

Firstly, the information about which context a device's stream IDs are
associated with is already present by necessity in the S2CR. With that
state easily accessible we can refer directly to it and obviate the need
to track an IOMMU domain in each device's archdata (its earlier purpose
of enforcing correct attachment of multi-device groups now being handled
by the IOMMU core itself).

Secondly, the core API now deprecates explicit domain detach and expects
domain attach to move devices smoothly from one domain to another; for
SMMUv2, this notion maps directly to simply rewriting the S2CRs assigned
to the device. By giving the driver a suitable abstraction of those
S2CRs to work with, we can massively reduce the overhead of the current
heavy-handed "detach, free resources, reallocate resources, attach"
approach.

Thirdly, making the software state hardware-shaped and attached to the
SMMU instance once again makes suspend/resume of this register group
that much simpler to implement in future.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

In order to consider SMR masking, we really want to be able to validate
ID/mask pairs against existing SMR contents to prevent stream match
conflicts, which at best would cause transactions to fault unexpectedly,
and at worst lead to silent unpredictable behaviour. With our SMMU
instance data holding only an allocator bitmap, and the SMR values
themselves scattered across master configs hanging off devices which we
may have no way of finding, there's essentially no way short of digging
everything back out of the hardware. Similarly, the thought of power
management ops to support suspend/resume faces the exact same problem.

By massaging the software state into a closer shape to the underlying
hardware, everything comes together quite nicely; the allocator and the
high-level view of the data become a single centralised state which we
can easily keep track of, and to which any updates can be validated in
full before being synchronised to the hardware itself.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Rather than assuming fixed worst-case values for stream IDs and SMR
masks, keep track of whatever implemented bits the hardware actually
reports. This also obviates the slightly questionable validation of SMR
fields in isolation - rather than aborting the whole SMMU probe for a
hardware configuration which is still architecturally valid, we can
simply refuse masters later if they try to claim an unrepresentable ID
or mask (which almost certainly implies a DT error anyway).
Acked-by: NWill Deacon <will.deacon@arm.com>
Tested-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Fill in the last bits of machinery required to drive a stage 1 context
bank in v7 short descriptor format. By default we'll prefer to use it
only when the CPUs are also using the same format, such that we're
guaranteed that everything will be strictly 32-bit.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

There is no need to call devm_free_irq when driver detach.
devres_release_all which is called after 'drv->remove' will
release all managed resources.
Signed-off-by: NPeng Fan <van.freenix@gmail.com>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Enabling stalling faults can result in hardware deadlock on poorly
designed systems, particularly those with a PCI root complex upstream of
the SMMU.

Although it's not really Linux's job to save hardware integrators from
their own misfortune, it *is* our job to stop userspace (e.g. VFIO
clients) from hosing the system for everybody else, even if they might
already be required to have elevated privileges.

Given that the fault handling code currently executes entirely in IRQ
context, there is nothing that can sensibly be done to recover from
things like page faults anyway, so let's rip this code out for now and
avoid the potential for deadlock.

Cc: <stable@vger.kernel.org>
Fixes: 48ec83bc ("iommu/arm-smmu: Add initial driver support for ARM SMMUv3 devices")
Reported-by: NMatt Evans <matt.evans@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Use devm_request_irq to simplify error handling path,
when probe smmu device.

Also devm_{request|free}_irq when init or destroy domain context.
Signed-off-by: NPeng Fan <van.freenix@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The PCIe ACS capability will affect the layout of iommu groups.
Generally speaking, if the path from root port to the PCIe device
is ACS enabled, the iommu will create a single iommu group for this
PCIe device. If all PCIe devices on the path are ACS enabled then
Linux can determine this path is ACS enabled.

Linux use two PCIe configuration registers to determine the ACS
status of PCIe devices:
ACS Capability Register and ACS Control Register.

The first register is used to check the implementation of ACS function
of a PCIe device, the second register is used to check the enable status
of ACS function. If one PCIe device has implemented and enabled the ACS
function then Linux will determine this PCIe device enabled ACS.

From the Chapter:6.12 of PCI Express Base Specification Revision 3.1a,
we can find that when a PCIe device implements ACS function, the enable
status is set to disabled by default and can be enabled by ACS-aware
software.

ACS will affect the iommu groups topology, so, the iommu driver is
ACS-aware software. This patch adds a call to pci_request_acs() to the
arm-smmu driver to enable the ACS function in PCIe devices that support
it, when they get probed.
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Signed-off-by: NWei Chen <Wei.Chen@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.

However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.

Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.

This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.

Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.

I was using this definition for testing:

 #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
       unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))

which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.

I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.

[ Updated the 9p parts as per Al Viro  - Linus ]
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that we can accurately reflect the context format we choose for each
domain, do that instead of imposing the global lowest-common-denominator
restriction and potentially ending up with nothing. We currently have a
strict 1:1 correspondence between domains and context banks, so we don't
need to entertain the possibility of multiple formats _within_ a domain.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
[rm: split from original patch, added SMMUv3]
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

According MMU-500r2 TRM, section 3.7.1 Auxiliary Control registers,
You can modify ACTLR only when the ACR.CACHE_LOCK bit is 0.

So before clearing ARM_MMU500_ACTLR_CPRE of each context bank,
need clear CACHE_LOCK bit of ACR register first.

Since CACHE_LOCK bit is only present in MMU-500r2 onwards,
need to check the major number of IDR7.
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NPeng Fan <van.freenix@gmail.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The 64KB Translation Granule Supplement to the SMMUv1 architecture
allows an SMMUv1 implementation to support 64KB pages for stage 2
translations, using a constrained VMSAv8 descriptor format limited
to 40-bit addresses. Now that we can freely mix and match context
formats, we can actually handle having 4KB pages via an AArch32
context but 64KB pages via an AArch64 context, so plumb it in.

It is assumed that any implementations will have hardware capabilities
matching the format constraints, thus obviating the need for excessive
sanity-checking; this is the case for MMU-401, the only ARM Ltd.
implementation.

CC: Eric Auger <eric.auger@linaro.org>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The way the driver currently forces an AArch32 or AArch64 context format
based on the kernel config and SMMU architecture version is suboptimal,
in that it makes it very hard to support oddball mix-and-match cases
like the SMMUv1 64KB supplement, or situations where the reduced table
depth of an AArch32 short descriptor context may be desirable under an
AArch64 kernel. It also only happens to work on current implementations
which do support all the relevant formats.

Introduce an explicit notion of context format, so we can manage that
independently and get rid of the inflexible #ifdeffery.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

With {read,write}q_relaxed now able to fall back to the common
nonatomic-hi-lo helper, make use of that so that we don't have to
open-code our own. In the process, also convert the other remaining
split accesses, and repurpose the custom accessor to smooth out the
couple of troublesome instances where we really want to avoid
nonatomic writes (and a 64-bit access is unnecessary in the 32-bit
context formats we would use on a 32-bit CPU).

This paves the way for getting rid of some of the assumptions currently
baked into the driver which make it really awkward to use 32-bit context
formats with SMMUv2 under a 64-bit kernel.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

MMU-500 erratum #841119 is tickled by a particular set of circumstances
interacting with the next-page prefetcher. Since said prefetcher is
quite dumb and actually detrimental to performance in some cases (by
causing unwanted TLB evictions for non-sequential access patterns), we
lose very little by turning it off, and what we gain is a guarantee that
the erratum is never hit.

As a bonus, the same workaround will also prevent erratum #826419 once
v7 short descriptor support is implemented.

CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

With a framework for implementation-specific funtionality in place, the
currently-FDT-dependent ThunderX workaround gets to be the first user.
Acked-by: NTirumalesh Chalamarla <tchalamarla@caviumnetworks.com>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

As the inevitable reality of implementation-specific errata workarounds
begin to accrue alongside our integration quirk handling, it's about
time the driver had a decent way of keeping track. Extend the per-SMMU
data so we can identify specific implementations in an efficient and
firmware-agnostic manner.
Acked-by: NTirumalesh Chalamarla <tchalamarla@caviumnetworks.com>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Due to erratum #27704, the CN88xx SMMUv2 implementation supports only
shared ASID and VMID numberspaces.

This patch ensures that ASID and VMIDs are unique across all SMMU
instances on affected Cavium systems.
Signed-off-by: NTirumalesh Chalamarla <tchalamarla@caviumnetworks.com>
Signed-off-by: NAkula Geethasowjanya <Geethasowjanya.Akula@caviumnetworks.com>
[will: commit message, comments and formatting]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This patch adds support for 16-bit VMIDs on implementations of SMMUv2
that support it.
Signed-off-by: NTirumalesh Chalamarla <tchalamarla@caviumnetworks.com>
[will: commit messsage and comments]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Until we get fully plumbed into of_iommu_configure, our default
IOMMU_DOMAIN_DMA domains just bypass translation. Since we achieve that
by leaving the stream table entries set to bypass instead of pointing at
a translation context, the context bank we allocate for the domain is
completely wasted. Context banks are typically a rather limited
resource, so don't hog ones we don't need.
Reported-by: NEric Auger <eric.auger@linaro.org>
Tested-by: NEric Auger <eric.auger@linaro.org>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Commit cbf8277e ("iommu/arm-smmu: Treat IOMMU_DOMAIN_DMA as bypass
for now") ignores requests to attach a device to the default domain
since, without IOMMU-basked DMA ops available everywhere, the default
domain will just lead to unexpected transaction faults being reported.

Unfortunately, the way this was implemented on SMMUv2 causes a
regression with VFIO PCI device passthrough under KVM on AMD Seattle.
On this system, the host controller device is associated with both a
pci_dev *and* a platform_device, and can therefore end up with duplicate
SMR entries, resulting in a stream-match conflict at runtime.

This patch amends the original fix so that attaching to IOMMU_DOMAIN_DMA
is rejected even before configuring the SMRs. This restores the old
behaviour for now, but we'll need to look at handing host controllers
specially when we come to supporting the default domain fully.
Reported-by: NEric Auger <eric.auger@linaro.org>
Tested-by: NEric Auger <eric.auger@linaro.org>
Tested-by: NYang Shi <yang.shi@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Remove the usage of of_parse_phandle_with_args() and replace
it by the phandle-iterator implementation so that we can
parse out all of the potentially present 128 stream-ids.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRob Herring <robh@kernel.org>

Until all upstream devices have their DMA ops swizzled to point at the
SMMU, we need to treat the IOMMU_DOMAIN_DMA domain as bypass to avoid
putting devices into an empty address space when detaching from VFIO.
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The ARM SMMU attach_dev implementations returns -EEXIST if the device
being attached is already attached to a domain. This doesn't play nicely
with the default domain, resulting in splats such as:

  WARNING: at drivers/iommu/iommu.c:1257
  Modules linked in:

  CPU: 3 PID: 1939 Comm: virtio-net-tx Tainted: G S              4.5.0-rc4+ #1
  Hardware name: FVP Base (DT)
  task: ffffffc87a9d0000 ti: ffffffc07a278000 task.ti: ffffffc07a278000
  PC is at __iommu_detach_group+0x68/0xe8
  LR is at __iommu_detach_group+0x48/0xe8

This patch fixes the problem by forcefully detaching the device from
its old domain, if present, when attaching to a new one. The unused
->detach_dev callback is also removed the iommu_ops structures.
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Borrow the disable_bypass parameter from the SMMUv3 driver as a handy
debugging/security feature so that unmatched stream IDs (i.e. devices
not attached to an IOMMU domain) may be configured to fault.

Rather than introduce unsightly inconsistency, or repeat the existing
unnecessary use of module_param_named(), fix that as well in passing.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

With DMA mapping ops provided by the iommu-dma code, only a minimal
contribution from the IOMMU driver is needed to create a suitable
DMA-API domain for them to use. Implement this for the ARM SMMUs.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The IOMMU API has no concept of privilege so assumes all devices and
mappings are equal, and indeed most non-CPU master devices on an AMBA
interconnect make little use of the attribute bits on the bus thus by
default perform unprivileged data accesses.

Some devices, however, believe themselves more equal than others, such
as programmable DMA controllers whose 'master' thread issues bus
transactions marked as privileged instruction fetches, while the data
accesses of its channel threads (under the control of Linux, at least)
are marked as unprivileged. This poses a problem for implementing the
DMA API on an IOMMU conforming to ARM VMSAv8, under which a page that is
unprivileged-writeable is also implicitly privileged-execute-never.
Given that, there is no one set of attributes with which iommu_map() can
implement, say, dma_alloc_coherent() that will allow every possible type
of access without something running into unexecepted permission faults.

Fortunately the SMMU architecture provides a means to mitigate such
issues by overriding the incoming attributes of a transaction; make use
of that to strip the privileged/unprivileged status off incoming
transactions, leaving just the instruction/data dichotomy which the
IOMMU API does at least understand; Four states good, two states better.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When invalidating an IOVA range potentially spanning multiple pages,
such as when removing an entire intermediate-level table, we currently
only issue an invalidation for the first IOVA of that range. Since the
architecture specifies that address-based TLB maintenance operations
target a single entry, an SMMU could feasibly retain live entries for
subsequent pages within that unmapped range, which is not good.

Make sure we hit every possible entry by iterating over the whole range
at the granularity provided by the pagetable implementation.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
[will: added missing semicolons...]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

IOMMU hardware with range-based TLB maintenance commands can work
happily with the iova and size arguments passed via the tlb_add_flush
callback, but for IOMMUs which require separate commands per entry in
the range, it is not straightforward to infer the necessary granularity
when it comes to issuing the actual commands.

Add an additional argument indicating the granularity for the benefit
of drivers needing to know, and update the ARM LPAE code appropriately
(for non-leaf invalidations we currently just assume the worst-case
page granularity rather than walking the table to check).
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The basic flow for add a device:
 arm_smmu_add_device
        |->iommu_group_get_for_dev
            |->iommu_group_get
                     return group;  (1)
            |->ops->device_group : Init/increase reference count to/by 1.
            |->iommu_group_add_device : Increase reference count by 1.
		     return group   (2)
        |->return 0;

Since we are adding one device, the flow is (2) and the group reference
count will be increased by 2. So, we need to add iommu_group_put at the
end of arm_smmu_add_device to decrease the count by 1.

Also take the failure path into consideration when fail to add a device.
Signed-off-by: NPeng Fan <van.freenix@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>