A prior commit e0f3c3f7 ("mm/mmu_notifier: init notifier if necessary")
made an attempt at doing this, but had to be reverted as calling
the GFP_KERNEL allocator under the i_mmap_mutex causes deadlock, see
commit 35cfa2b0 ("mm/mmu_notifier: allocate mmu_notifier in advance").

However, we can avoid that problem by doing the allocation only under
the mmap_sem, which is already happening.

Since all writers to mm->mmu_notifier_mm hold the write side of the
mmap_sem reading it under that sem is deterministic and we can use that to
decide if the allocation path is required, without speculation.

The actual update to mmu_notifier_mm must still be done under the
mm_take_all_locks() to ensure read-side coherency.

Link: https://lore.kernel.org/r/20190806231548.25242-3-jgg@ziepe.caReviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NRalph Campbell <rcampbell@nvidia.com>
Tested-by: NRalph Campbell <rcampbell@nvidia.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This simplifies the code to not have so many one line functions and extra
logic. __mmu_notifier_register() simply becomes the entry point to
register the notifier, and the other one calls it under lock.

Also add a lockdep_assert to check that the callers are holding the lock
as expected.

Link: https://lore.kernel.org/r/20190806231548.25242-2-jgg@ziepe.caSuggested-by: NChristoph Hellwig <hch@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NRalph Campbell <rcampbell@nvidia.com>
Tested-by: NRalph Campbell <rcampbell@nvidia.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Make HMM_MIRROR an option that is selected by drivers wanting to use it
instead of a user visible option as it is just a low-level implementation
detail.

Link: https://lore.kernel.org/r/20190806160554.14046-15-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

There isn't really any architecture specific code in this page table walk
implementation, so drop the dependencies.

Link: https://lore.kernel.org/r/20190806160554.14046-14-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Stub out the whole function and assign NULL to the .hugetlb_entry method
if CONFIG_HUGETLB_PAGE is not set, as the method won't ever be called in
that case.

Link: https://lore.kernel.org/r/20190806160554.14046-13-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Stub out the whole function when CONFIG_TRANSPARENT_HUGEPAGE is not set to
make the function easier to read.

Link: https://lore.kernel.org/r/20190806160554.14046-12-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

We only need the special pud_entry walker if PUD-sized hugepages and pte
mappings are supported, else the common pagewalk code will take care of
the iteration.  Not implementing this callback reduced the amount of code
compiled for non-x86 platforms, and also fixes compile failures with other
architectures when helpers like pud_pfn are not implemented.

Link: https://lore.kernel.org/r/20190806160554.14046-11-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

pte_index is an internal arch helper in various architectures, without
consistent semantics.  Open code that calculation of a PMD index based on
the virtual address instead.

Link: https://lore.kernel.org/r/20190806160554.14046-10-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The pagewalk code already passes the value as the hmask parameter.

Link: https://lore.kernel.org/r/20190806160554.14046-9-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

All users pass PAGE_SIZE here, and if we wanted to support single entries
for huge pages we should really just add a HMM_FAULT_HUGEPAGE flag instead
that uses the huge page size instead of having the caller calculate that
size once, just for the hmm code to verify it.

Link: https://lore.kernel.org/r/20190806160554.14046-8-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The start, end and page_shift values are all saved in the range structure,
so we might as well use that for argument passing.

Link: https://lore.kernel.org/r/20190806160554.14046-7-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Link: https://lore.kernel.org/r/20190806160554.14046-6-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

We'll need the nouveau_svmm structure to improve the function soon.  For
now this allows using the svmm->mm reference to unlock the mmap_sem, and
thus the same dereference chain that the caller uses to lock and unlock
it.

Link: https://lore.kernel.org/r/20190806160554.14046-4-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The list is used to add the range to another list as an entry in the core
hmm code, and intended as a private member not exposed to drivers.  There
is no need to initialize it in a driver.

Link: https://lore.kernel.org/r/20190806160554.14046-3-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

hmm_range_fault can only return -EAGAIN if called with the
HMM_FAULT_ALLOW_RETRY flag, which amdgpu never does.  Remove the handling
for the -EAGAIN case with its non-standard locking scheme.

Link: https://lore.kernel.org/r/20190806160554.14046-2-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Since hmm_range_fault() doesn't use the struct hmm_range vma field, remove
it.

Link: https://lore.kernel.org/r/20190726005650.2566-8-rcampbell@nvidia.comSuggested-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NRalph Campbell <rcampbell@nvidia.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

walk_page_range() will only call hmm_vma_walk_hugetlb_entry() for
hugetlbfs pages and doesn't call hmm_vma_walk_pmd() in this case.

Therefore, it is safe to remove the check for vma->vm_flags & VM_HUGETLB
in hmm_vma_walk_pmd().

Link: https://lore.kernel.org/r/20190726005650.2566-7-rcampbell@nvidia.comSigned-off-by: NRalph Campbell <rcampbell@nvidia.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Add a HMM_FAULT_SNAPSHOT flag so that hmm_range_snapshot can be merged
into the almost identical hmm_range_fault function.

Link: https://lore.kernel.org/r/20190726005650.2566-5-rcampbell@nvidia.comSigned-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NRalph Campbell <rcampbell@nvidia.com>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This allows easier expansion to other flags, and also makes the callers a
little easier to read.

Link: https://lore.kernel.org/r/20190726005650.2566-4-rcampbell@nvidia.comSigned-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NRalph Campbell <rcampbell@nvidia.com>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

A few more comments and minor programming style clean ups.  There should
be no functional changes.

Link: https://lore.kernel.org/r/20190726005650.2566-3-rcampbell@nvidia.comSigned-off-by: NRalph Campbell <rcampbell@nvidia.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The hmm_mirror_ops callback function sync_cpu_device_pagetables() passes a
struct hmm_update which is a simplified version of struct
mmu_notifier_range. This is unnecessary so replace hmm_update with
mmu_notifier_range directly.

Link: https://lore.kernel.org/r/20190726005650.2566-2-rcampbell@nvidia.comSigned-off-by: NRalph Campbell <rcampbell@nvidia.com>
Reviewed: Christoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
[jgg: white space tuning]
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The magic dropping of mmap_sem when handle_mm_fault returns VM_FAULT_RETRY
is rather subtile.  Add a comment explaining it.

Link: https://lore.kernel.org/r/20190724065258.16603-8-hch@lst.deTested-by: NRalph Campbell <rcampbell@nvidia.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
[hch: wrote a changelog]
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Switch the one remaining user in nouveau over to its replacement, and
remove all the wrappers.

Link: https://lore.kernel.org/r/20190724065258.16603-7-hch@lst.deTested-by: NRalph Campbell <rcampbell@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NRalph Campbell <rcampbell@nvidia.com>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

-EAGAIN has a magic meaning for non-blocking faults, so don't overload it.
Given that the caller doesn't check for specific error codes this change
is purely cosmetic.

Link: https://lore.kernel.org/r/20190724065258.16603-6-hch@lst.deTested-by: NRalph Campbell <rcampbell@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Currently nouveau_svm_fault expects nouveau_range_fault to never unlock
mmap_sem, but the latter unlocks it for a random selection of error
codes. Fix this up by always unlocking mmap_sem for non-zero return values
in nouveau_range_fault, and only unlocking it in the caller for successful
returns.

Link: https://lore.kernel.org/r/20190724065258.16603-5-hch@lst.deTested-by: NRalph Campbell <rcampbell@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The parameter is always false, so remove it as well as the -EAGAIN
handling that can only happen for the non-blocking case.

Link: https://lore.kernel.org/r/20190724065258.16603-4-hch@lst.deTested-by: NRalph Campbell <rcampbell@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

These two functions are marked as a legacy APIs to get rid of, but seem to
suit the current nouveau flow.  Move it to the only user in preparation
for fixing a locking bug involving caller and callee.  All comments
referring to the old API have been removed as this now is a driver private
helper.

Link: https://lore.kernel.org/r/20190724065258.16603-3-hch@lst.deTested-by: NRalph Campbell <rcampbell@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

We should not have two different error codes for the same
condition. EAGAIN must be reserved for the FAULT_FLAG_ALLOW_RETRY retry
case and signals to the caller that the mmap_sem has been unlocked.

Use EBUSY for the !valid case so that callers can get the locking right.

Link: https://lore.kernel.org/r/20190724065258.16603-2-hch@lst.deTested-by: NRalph Campbell <rcampbell@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NRalph Campbell <rcampbell@nvidia.com>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NFelix Kuehling <Felix.Kuehling@amd.com>
[jgg: elaborated commit message]
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Pull Devicetree fixes from Rob Herring:
 "Fix several warnings/errors in validation of binding schemas"

* tag 'devicetree-fixes-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  dt-bindings: pinctrl: stm32: Fix missing 'clocks' property in examples
  dt-bindings: iio: ad7124: Fix dtc warnings in example
  dt-bindings: iio: avia-hx711: Fix avdd-supply typo in example
  dt-bindings: pinctrl: aspeed: Fix AST2500 example errors
  dt-bindings: pinctrl: aspeed: Fix 'compatible' schema errors
  dt-bindings: riscv: Limit cpus schema to only check RiscV 'cpu' nodes
  dt-bindings: Ensure child nodes are of type 'object'

Pull vfs documentation typo fix from Al Viro.

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  typo fix: it's d_make_root, not d_make_inode...

Pull cifs fixes from Steve French:
 "Two fixes for stable, one that had dependency on earlier patch in this
  merge window and can now go in, and a perf improvement in SMB3 open"

* tag '5.3-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update internal module number
  cifs: flush before set-info if we have writeable handles
  smb3: optimize open to not send query file internal info
  cifs: copy_file_range needs to strip setuid bits and update timestamps
  CIFS: fix deadlock in cached root handling

The commit b3aa14f0 ("iommu: remove the mapping_error dma_map_ops
method") incorrectly changed the checking from dma_ops_alloc_iova() in
map_sg() causes a crash under memory pressure as dma_ops_alloc_iova()
never return DMA_MAPPING_ERROR on failure but 0, so the error handling
is all wrong.

   kernel BUG at drivers/iommu/iova.c:801!
    Workqueue: kblockd blk_mq_run_work_fn
    RIP: 0010:iova_magazine_free_pfns+0x7d/0xc0
    Call Trace:
     free_cpu_cached_iovas+0xbd/0x150
     alloc_iova_fast+0x8c/0xba
     dma_ops_alloc_iova.isra.6+0x65/0xa0
     map_sg+0x8c/0x2a0
     scsi_dma_map+0xc6/0x160
     pqi_aio_submit_io+0x1f6/0x440 [smartpqi]
     pqi_scsi_queue_command+0x90c/0xdd0 [smartpqi]
     scsi_queue_rq+0x79c/0x1200
     blk_mq_dispatch_rq_list+0x4dc/0xb70
     blk_mq_sched_dispatch_requests+0x249/0x310
     __blk_mq_run_hw_queue+0x128/0x200
     blk_mq_run_work_fn+0x27/0x30
     process_one_work+0x522/0xa10
     worker_thread+0x63/0x5b0
     kthread+0x1d2/0x1f0
     ret_from_fork+0x22/0x40

Fixes: b3aa14f0 ("iommu: remove the mapping_error dma_map_ops method")
Signed-off-by: NQian Cai <cai@lca.pw>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The hexagon implementation pte_alloc_one(), pte_alloc_one_kernel(),
pte_free_kernel() and pte_free() is identical to the generic except of
lack of __GFP_ACCOUNT for the user PTEs allocation.

Switch hexagon to use generic version of these functions.
Signed-off-by: NMike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull NTB updates from Jon Mason:
 "New feature to add support for NTB virtual MSI interrupts, the ability
  to test and use this feature in the NTB transport layer.

  Also, bug fixes for the AMD and Switchtec drivers, as well as some
  general patches"

* tag 'ntb-5.3' of git://github.com/jonmason/ntb: (22 commits)
  NTB: Describe the ntb_msi_test client in the documentation.
  NTB: Add MSI interrupt support to ntb_transport
  NTB: Add ntb_msi_test support to ntb_test
  NTB: Introduce NTB MSI Test Client
  NTB: Introduce MSI library
  NTB: Rename ntb.c to support multiple source files in the module
  NTB: Introduce functions to calculate multi-port resource index
  NTB: Introduce helper functions to calculate logical port number
  PCI/switchtec: Add module parameter to request more interrupts
  PCI/MSI: Support allocating virtual MSI interrupts
  ntb_hw_switchtec: Fix setup MW with failure bug
  ntb_hw_switchtec: Skip unnecessary re-setup of shared memory window for crosslink case
  ntb_hw_switchtec: Remove redundant steps of switchtec_ntb_reinit_peer() function
  NTB: correct ntb_dev_ops and ntb_dev comment typos
  NTB: amd: Silence shift wrapping warning in amd_ntb_db_vector_mask()
  ntb_hw_switchtec: potential shift wrapping bug in switchtec_ntb_init_sndev()
  NTB: ntb_transport: Ensure qp->tx_mw_dma_addr is initaliazed
  NTB: ntb_hw_amd: set peer limit register
  NTB: ntb_perf: Clear stale values in doorbell and command SPAD register
  NTB: ntb_perf: Disable NTB link after clearing peer XLAT registers
  ...

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Now that examples are validated against the DT schema, an error with
required 'clocks' property missing is exposed:

Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.example.dt.yaml: \
pinctrl@40020000: gpio@0: 'clocks' is a required property
Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.example.dt.yaml: \
pinctrl@50020000: gpio@1000: 'clocks' is a required property
Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.example.dt.yaml: \
pinctrl@50020000: gpio@2000: 'clocks' is a required property

Add the missing 'clocks' properties to the examples to fix the errors.

Fixes: 2c9239c1 ("dt-bindings: pinctrl: Convert stm32 pinctrl bindings to json-schema")
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: linux-gpio@vger.kernel.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Acked-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NRob Herring <robh@kernel.org>

With the conversion to DT schema, the examples are now compiled with
dtc. The ad7124 binding example has the following warning:

Documentation/devicetree/bindings/iio/adc/adi,ad7124.example.dts:19.11-21: \
Warning (reg_format): /example-0/adc@0:reg: property has invalid length (4 bytes) (#address-cells == 1, #size-cells == 1)

There's a default #size-cells and #address-cells values of 1 for
examples. For examples needing different values such as this one on a
SPI bus, they need to provide a SPI bus parent node.

Fixes: 26ae15e6 ("Convert AD7124 bindings documentation to YAML format.")

Cc: Jonathan Cameron <jic23@kernel.org>
Cc: linux-iio@vger.kernel.org
Signed-off-by: NRob Herring <robh@kernel.org>

Now that examples are validated against the DT schema, a typo in
avia-hx711 example generates a warning:

Documentation/devicetree/bindings/iio/adc/avia-hx711.example.dt.yaml: weight: 'avdd-supply' is a required property

Fix the typo.

Fixes: 5150ec3f ("avia-hx711.yaml: transform DT binding to YAML")
Cc: Andreas Klinger <ak@it-klinger.de>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: linux-iio@vger.kernel.org
Signed-off-by: NRob Herring <robh@kernel.org>

The schema examples are now validated against the schema itself. The
AST2500 pinctrl schema has a couple of errors:

Documentation/devicetree/bindings/pinctrl/aspeed,ast2500-pinctrl.example.dt.yaml: \
example-0: $nodename:0: 'example-0' does not match '^(bus|soc|axi|ahb|apb)(@[0-9a-f]+)?$'
Documentation/devicetree/bindings/pinctrl/aspeed,ast2500-pinctrl.example.dt.yaml: \
pinctrl: aspeed,external-nodes: [[1, 2]] is too short

Fixes: 0a617de1 ("dt-bindings: pinctrl: aspeed: Convert AST2500 bindings to json-schema")
Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Joel Stanley <joel@jms.id.au>
Cc: linux-aspeed@lists.ozlabs.org
Cc: linux-gpio@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Acked-by: NAndrew Jeffery <andrew@aj.id.au>
Signed-off-by: NRob Herring <robh@kernel.org>