<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/rust/kernel/dma.rs, branch v7.2-rc1</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'driver-core-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core</title>
<updated>2026-06-15T07:11:17+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-06-15T07:11:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=36808d5e983985bbda87e01059cccc071fe3ec8d'/>
<id>36808d5e983985bbda87e01059cccc071fe3ec8d</id>
<content type='text'>
Pull driver core updates from Danilo Krummrich:
 "Deferred probe:
   - Fix race where deferred probe timeout work could be permanently
     canceled by using mod_delayed_work()
   - Fix missing jiffies conversion in deferred_probe_extend_timeout()
   - Guard timeout extension with delayed_work_pending() to prevent
     premature firing
   - Use system_percpu_wq instead of the deprecated system_wq
   - Update deferred_probe_timeout documentation

  device:
   - Replace direct struct device bitfield access (can_match, dma_iommu,
     dma_skip_sync, dma_ops_bypass, state_synced, dma_coherent,
     of_node_reused, offline, offline_disabled) with flag-based
     accessors using bit operations
   - Reject devices with unregistered buses
   - Delete unused DEVICE_ATTR_PREALLOC()
   - Add low-level device attribute macros with const show/store
     callbacks, allowing device attributes to reside in read-only memory
   - Move core device attributes to read-only memory
   - Constify group array pointers in driver_add_groups() /
     driver_remove_groups(), struct bus_type, and struct device_driver

  device property:
   - Fix fwnode reference leak in fwnode_graph_get_endpoint_by_id()
   - Initialize all fields of fwnode_handle in fwnode_init()
   - Provide swnode_get()/swnode_put() wrappers around kobject_get/put()
   - Allow passing struct software_node_ref_args pointers directly to
     PROPERTY_ENTRY_REF()

  driver_override:
   - Migrate amba, cdx, vmbus, and rpmsg to the generic driver_override
     infrastructure, fixing a UAF from unsynchronized access to
     driver_override in bus match() callbacks
   - Remove the now-unused driver_set_override()

  firmware loader:
   - Fix recursive lock deadlock in device_cache_fw_images() when async
     work falls back to synchronous execution
   - Fix device reference leak in firmware_upload_register()

  platform:
   - Pass KBUILD_MODNAME through the platform driver registration macro
     to create module symlinks in sysfs for built-in drivers; move
     module_kset initialization to a pure_initcall and tegra cbb
     registration to core_initcall to ensure correct ordering
   - Pass THIS_MODULE implicitly through a coresight_init_driver() macro

  sysfs:
   - Upgrade OOB write detection in sysfs_kf_seq_show() from printk to
     WARN
   - Add return value clamping to sysfs_kf_read()

  Rust:
   - ACPI:

     Fix missing match data for PRP0001 by exporting
     acpi_of_match_device()

   - Auxiliary:

     Replace drvdata() with dedicated registration data on
     auxiliary_device. drvdata() exposed the driver's bus device private
     data beyond the driver's own scope, creating ordering constraints
     and forcing the data to outlive all registrations that access it.
     Registration data is instead scoped structurally to the
     Registration object, making lifecycle ordering enforced by
     construction rather than convention.

   - Rust-native device driver lifetimes (HRT):

     Allow Rust device drivers to carry a lifetime parameter on their
     bus device private data, tied to the device binding scope -- the
     interval during which a bus device is bound to a driver. Device
     resources like pci::Bar&lt;'a&gt; and IoMem&lt;'a&gt; can be stored directly in
     the driver's bus device private data with a lifetime bounded by the
     binding scope, so the compiler enforces at build time that they do
     not outlive the binding. This removes Devres indirection from every
     access site and eliminates try_access() failure paths in
     destructors.

     Bus driver traits use a Generic Associated Type (GAT) Data&lt;'bound&gt;
     to introduce the lifetime on the private data, rather than
     parameterizing the Driver trait itself. Auxiliary registration
     data, where the lifetime is not introduced by a trait callback but
     must be threaded through Registration, uses the ForLt trait (a
     type-level abstraction for types generic over a lifetime).

  Misc:
   - Fix DT overlayed devices not probing by reverting the broken
     treewide overlay fix and re-running fw_devlink consumer pickup when
     an overlay is applied to a bound device
   - Use root_device_register() for faux bus root device; add sanity
     check for failed bus init
   - Fix dev_has_sync_state() data race with READ_ONCE() and move it to
     base.h
   - Avoid spurious device_links warning when removing a device while
     its supplier is unbinding
   - Switch ISA bus to dynamic root device
   - Fix suspicious RCU usage in kernfs_put()
   - Remove devcoredump exit callback
   - Constify devfreq_event_class"

* tag 'driver-core-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core: (81 commits)
  software node: allow passing reference args to PROPERTY_ENTRY_REF()
  driver core: platform: set mod_name in driver registration
  coresight: pass THIS_MODULE implicitly through a macro
  kernel: param: initialize module_kset in a pure_initcall
  soc/tegra: cbb: Move driver registration from pure_initcall to core_initcall
  firmware_loader: Fix recursive lock in device_cache_fw_images()
  driver core: Use system_percpu_wq instead of system_wq
  driver core: remove driver_set_override()
  rpmsg: use generic driver_override infrastructure
  Drivers: hv: vmbus: use generic driver_override infrastructure
  cdx: use generic driver_override infrastructure
  amba: use generic driver_override infrastructure
  rust: devres: add 'static bound to Devres&lt;T&gt;
  samples: rust: rust_driver_auxiliary: showcase lifetime-bound registration data
  rust: auxiliary: generalize Registration over ForLt
  rust: types: add `ForLt` trait for higher-ranked lifetime support
  gpu: nova-core: separate driver type from driver data
  samples: rust: rust_driver_pci: use HRT lifetime for Bar
  rust: io: make IoMem and ExclusiveIoMem lifetime-parameterized
  rust: pci: make Bar lifetime-parameterized
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull driver core updates from Danilo Krummrich:
 "Deferred probe:
   - Fix race where deferred probe timeout work could be permanently
     canceled by using mod_delayed_work()
   - Fix missing jiffies conversion in deferred_probe_extend_timeout()
   - Guard timeout extension with delayed_work_pending() to prevent
     premature firing
   - Use system_percpu_wq instead of the deprecated system_wq
   - Update deferred_probe_timeout documentation

  device:
   - Replace direct struct device bitfield access (can_match, dma_iommu,
     dma_skip_sync, dma_ops_bypass, state_synced, dma_coherent,
     of_node_reused, offline, offline_disabled) with flag-based
     accessors using bit operations
   - Reject devices with unregistered buses
   - Delete unused DEVICE_ATTR_PREALLOC()
   - Add low-level device attribute macros with const show/store
     callbacks, allowing device attributes to reside in read-only memory
   - Move core device attributes to read-only memory
   - Constify group array pointers in driver_add_groups() /
     driver_remove_groups(), struct bus_type, and struct device_driver

  device property:
   - Fix fwnode reference leak in fwnode_graph_get_endpoint_by_id()
   - Initialize all fields of fwnode_handle in fwnode_init()
   - Provide swnode_get()/swnode_put() wrappers around kobject_get/put()
   - Allow passing struct software_node_ref_args pointers directly to
     PROPERTY_ENTRY_REF()

  driver_override:
   - Migrate amba, cdx, vmbus, and rpmsg to the generic driver_override
     infrastructure, fixing a UAF from unsynchronized access to
     driver_override in bus match() callbacks
   - Remove the now-unused driver_set_override()

  firmware loader:
   - Fix recursive lock deadlock in device_cache_fw_images() when async
     work falls back to synchronous execution
   - Fix device reference leak in firmware_upload_register()

  platform:
   - Pass KBUILD_MODNAME through the platform driver registration macro
     to create module symlinks in sysfs for built-in drivers; move
     module_kset initialization to a pure_initcall and tegra cbb
     registration to core_initcall to ensure correct ordering
   - Pass THIS_MODULE implicitly through a coresight_init_driver() macro

  sysfs:
   - Upgrade OOB write detection in sysfs_kf_seq_show() from printk to
     WARN
   - Add return value clamping to sysfs_kf_read()

  Rust:
   - ACPI:

     Fix missing match data for PRP0001 by exporting
     acpi_of_match_device()

   - Auxiliary:

     Replace drvdata() with dedicated registration data on
     auxiliary_device. drvdata() exposed the driver's bus device private
     data beyond the driver's own scope, creating ordering constraints
     and forcing the data to outlive all registrations that access it.
     Registration data is instead scoped structurally to the
     Registration object, making lifecycle ordering enforced by
     construction rather than convention.

   - Rust-native device driver lifetimes (HRT):

     Allow Rust device drivers to carry a lifetime parameter on their
     bus device private data, tied to the device binding scope -- the
     interval during which a bus device is bound to a driver. Device
     resources like pci::Bar&lt;'a&gt; and IoMem&lt;'a&gt; can be stored directly in
     the driver's bus device private data with a lifetime bounded by the
     binding scope, so the compiler enforces at build time that they do
     not outlive the binding. This removes Devres indirection from every
     access site and eliminates try_access() failure paths in
     destructors.

     Bus driver traits use a Generic Associated Type (GAT) Data&lt;'bound&gt;
     to introduce the lifetime on the private data, rather than
     parameterizing the Driver trait itself. Auxiliary registration
     data, where the lifetime is not introduced by a trait callback but
     must be threaded through Registration, uses the ForLt trait (a
     type-level abstraction for types generic over a lifetime).

  Misc:
   - Fix DT overlayed devices not probing by reverting the broken
     treewide overlay fix and re-running fw_devlink consumer pickup when
     an overlay is applied to a bound device
   - Use root_device_register() for faux bus root device; add sanity
     check for failed bus init
   - Fix dev_has_sync_state() data race with READ_ONCE() and move it to
     base.h
   - Avoid spurious device_links warning when removing a device while
     its supplier is unbinding
   - Switch ISA bus to dynamic root device
   - Fix suspicious RCU usage in kernfs_put()
   - Remove devcoredump exit callback
   - Constify devfreq_event_class"

* tag 'driver-core-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core: (81 commits)
  software node: allow passing reference args to PROPERTY_ENTRY_REF()
  driver core: platform: set mod_name in driver registration
  coresight: pass THIS_MODULE implicitly through a macro
  kernel: param: initialize module_kset in a pure_initcall
  soc/tegra: cbb: Move driver registration from pure_initcall to core_initcall
  firmware_loader: Fix recursive lock in device_cache_fw_images()
  driver core: Use system_percpu_wq instead of system_wq
  driver core: remove driver_set_override()
  rpmsg: use generic driver_override infrastructure
  Drivers: hv: vmbus: use generic driver_override infrastructure
  cdx: use generic driver_override infrastructure
  amba: use generic driver_override infrastructure
  rust: devres: add 'static bound to Devres&lt;T&gt;
  samples: rust: rust_driver_auxiliary: showcase lifetime-bound registration data
  rust: auxiliary: generalize Registration over ForLt
  rust: types: add `ForLt` trait for higher-ranked lifetime support
  gpu: nova-core: separate driver type from driver data
  samples: rust: rust_driver_pci: use HRT lifetime for Bar
  rust: io: make IoMem and ExclusiveIoMem lifetime-parameterized
  rust: pci: make Bar lifetime-parameterized
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: ptr: remove implicit index projection syntax</title>
<updated>2026-06-05T08:16:47+00:00</updated>
<author>
<name>Gary Guo</name>
<email>gary@garyguo.net</email>
</author>
<published>2026-06-02T14:17:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ab0a321b4030b6e1fbbd99210bb7b5d4bc89d5e4'/>
<id>ab0a321b4030b6e1fbbd99210bb7b5d4bc89d5e4</id>
<content type='text'>
All users have been converted to use keyworded index projection syntax to
explicitly state their intention when doing index projection.

Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Reviewed-by: Andreas Hindborg &lt;a.hindborg@kernel.org&gt;
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Signed-off-by: Gary Guo &lt;gary@garyguo.net&gt;
Acked-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://patch.msgid.link/20260602-projection-syntax-rework-v2-6-6989470f5440@garyguo.net
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
All users have been converted to use keyworded index projection syntax to
explicitly state their intention when doing index projection.

Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Reviewed-by: Andreas Hindborg &lt;a.hindborg@kernel.org&gt;
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Signed-off-by: Gary Guo &lt;gary@garyguo.net&gt;
Acked-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://patch.msgid.link/20260602-projection-syntax-rework-v2-6-6989470f5440@garyguo.net
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: dma: update to keyworded index projection syntax</title>
<updated>2026-06-05T08:16:46+00:00</updated>
<author>
<name>Gary Guo</name>
<email>gary@garyguo.net</email>
</author>
<published>2026-06-02T14:17:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bd8e8087cff52c2d04e1934e9dbe14b84ff6c795'/>
<id>bd8e8087cff52c2d04e1934e9dbe14b84ff6c795</id>
<content type='text'>
Demonstrate the preferred syntax of index projection in DMA documentation
and examples. A few `[i]?` cases are converted to demonstrate the new
variant.

Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Reviewed-by: Andreas Hindborg &lt;a.hindborg@kernel.org&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Signed-off-by: Gary Guo &lt;gary@garyguo.net&gt;
Acked-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://patch.msgid.link/20260602-projection-syntax-rework-v2-4-6989470f5440@garyguo.net
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Demonstrate the preferred syntax of index projection in DMA documentation
and examples. A few `[i]?` cases are converted to demonstrate the new
variant.

Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Reviewed-by: Andreas Hindborg &lt;a.hindborg@kernel.org&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Signed-off-by: Gary Guo &lt;gary@garyguo.net&gt;
Acked-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://patch.msgid.link/20260602-projection-syntax-rework-v2-4-6989470f5440@garyguo.net
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: ptr: add panicking index projection variant</title>
<updated>2026-06-05T08:16:11+00:00</updated>
<author>
<name>Gary Guo</name>
<email>gary@garyguo.net</email>
</author>
<published>2026-06-02T14:17:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=38c3cbf5072ed85cea1559cbb36a760f7dabb114'/>
<id>38c3cbf5072ed85cea1559cbb36a760f7dabb114</id>
<content type='text'>
There have been a few cases where the programmer knows that the indices are
in bounds but the compiler cannot deduce that. This is also
compiler-version-dependent, so using build indexing here can be
problematic. On the other hand, it is also not ideal to use the fallible
variant, as it adds an error handling path that is never hit.

Add a new panicking index projection for this scenario. Like all panicking
operations, this should be used carefully only in cases where the user
knows the index is going to be in bounds, and panicking would indicate
something is catastrophically wrong.

To signify this, require users to explicitly denote the type of index being
used. The existing two types of index projections also gain the keyworded
version, which will be the recommended way going forward.

The keyworded syntax also paves the way of perhaps adding more flavors in
the future, e.g. `unsafe` index projection. However, unless the code is
extremely performance sensitive and bounds checking cannot be tolerated,
the panicking variant is safer and should be preferred, so it will be left
to the future when demand arises.

Signed-off-by: Gary Guo &lt;gary@garyguo.net&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Reviewed-by: Andreas Hindborg &lt;a.hindborg@kernel.org&gt;
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Acked-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://patch.msgid.link/20260602-projection-syntax-rework-v2-3-6989470f5440@garyguo.net
[ Fixed broken intra-doc link. Added a few extra intra-doc links. Reworded
  some docs slightly. - Miguel ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There have been a few cases where the programmer knows that the indices are
in bounds but the compiler cannot deduce that. This is also
compiler-version-dependent, so using build indexing here can be
problematic. On the other hand, it is also not ideal to use the fallible
variant, as it adds an error handling path that is never hit.

Add a new panicking index projection for this scenario. Like all panicking
operations, this should be used carefully only in cases where the user
knows the index is going to be in bounds, and panicking would indicate
something is catastrophically wrong.

To signify this, require users to explicitly denote the type of index being
used. The existing two types of index projections also gain the keyworded
version, which will be the recommended way going forward.

The keyworded syntax also paves the way of perhaps adding more flavors in
the future, e.g. `unsafe` index projection. However, unless the code is
extremely performance sensitive and bounds checking cannot be tolerated,
the panicking variant is safer and should be preferred, so it will be left
to the future when demand arises.

Signed-off-by: Gary Guo &lt;gary@garyguo.net&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Reviewed-by: Andreas Hindborg &lt;a.hindborg@kernel.org&gt;
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Acked-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://patch.msgid.link/20260602-projection-syntax-rework-v2-3-6989470f5440@garyguo.net
[ Fixed broken intra-doc link. Added a few extra intra-doc links. Reworded
  some docs slightly. - Miguel ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: device: make Core and CoreInternal lifetime-parameterized</title>
<updated>2026-05-27T14:22:42+00:00</updated>
<author>
<name>Danilo Krummrich</name>
<email>dakr@kernel.org</email>
</author>
<published>2026-05-25T20:20:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=24799831d631239ff21ea1bf7feee832df48b81f'/>
<id>24799831d631239ff21ea1bf7feee832df48b81f</id>
<content type='text'>
Device&lt;Core&gt; references in probe callbacks are scoped to the callback,
not the full binding duration. Add a lifetime parameter to Core and
CoreInternal to accurately represent this in the type system.

Suggested-by: Gary Guo &lt;gary@garyguo.net&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Reviewed-by: Eliot Courtney &lt;ecourtney@nvidia.com&gt;
Reviewed-by: Gary Guo &lt;gary@garyguo.net&gt;
Link: https://patch.msgid.link/20260525202921.124698-12-dakr@kernel.org
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Device&lt;Core&gt; references in probe callbacks are scoped to the callback,
not the full binding duration. Add a lifetime parameter to Core and
CoreInternal to accurately represent this in the type system.

Suggested-by: Gary Guo &lt;gary@garyguo.net&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Reviewed-by: Eliot Courtney &lt;ecourtney@nvidia.com&gt;
Reviewed-by: Gary Guo &lt;gary@garyguo.net&gt;
Link: https://patch.msgid.link/20260525202921.124698-12-dakr@kernel.org
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: dma: add from-slice constructors for Coherent and CoherentBox</title>
<updated>2026-03-28T13:20:07+00:00</updated>
<author>
<name>Alexandre Courbot</name>
<email>acourbot@nvidia.com</email>
</author>
<published>2026-03-26T15:22:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=816718c611cab2164d718b91ad8204afcd0af81f'/>
<id>816718c611cab2164d718b91ad8204afcd0af81f</id>
<content type='text'>
A very common pattern is to create a block of coherent memory with the
content of an already-existing slice of bytes (e.g. a loaded firmware
blob).

`CoherentBox` makes this easier, but still implies a potentially
panicking operation with `copy_from_slice` that requires a `PANIC`
comment.

Add `from_slice_with_attrs` and `from_slice` methods to both `Coherent`
and `CoherentBox` to turn this into a trivial one-step operation.

Reviewed-by: Andreas Hindborg &lt;a.hindborg@kernel.org&gt;
Reviewed-by: Gary Guo &lt;gary@garyguo.net&gt;
Reviewed-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://patch.msgid.link/20260327-b4-nova-dma-removal-v2-1-616e1d0b5cb3@nvidia.com
Signed-off-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A very common pattern is to create a block of coherent memory with the
content of an already-existing slice of bytes (e.g. a loaded firmware
blob).

`CoherentBox` makes this easier, but still implies a potentially
panicking operation with `copy_from_slice` that requires a `PANIC`
comment.

Add `from_slice_with_attrs` and `from_slice` methods to both `Coherent`
and `CoherentBox` to turn this into a trivial one-step operation.

Reviewed-by: Andreas Hindborg &lt;a.hindborg@kernel.org&gt;
Reviewed-by: Gary Guo &lt;gary@garyguo.net&gt;
Reviewed-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://patch.msgid.link/20260327-b4-nova-dma-removal-v2-1-616e1d0b5cb3@nvidia.com
Signed-off-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: dma: add CoherentHandle for DMA allocations without kernel mapping</title>
<updated>2026-03-28T13:13:23+00:00</updated>
<author>
<name>Danilo Krummrich</name>
<email>dakr@kernel.org</email>
</author>
<published>2026-03-21T17:27:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6dd782af1eb6be16a80349ea7822f0f8a23bb3e8'/>
<id>6dd782af1eb6be16a80349ea7822f0f8a23bb3e8</id>
<content type='text'>
Add CoherentHandle, an opaque DMA allocation type for buffers that are
only ever accessed by hardware. Unlike Coherent&lt;T&gt;, it does not provide
CPU access to the allocated memory.

CoherentHandle implicitly sets DMA_ATTR_NO_KERNEL_MAPPING and stores the
value returned by dma_alloc_attrs() as an opaque handle
(NonNull&lt;c_void&gt;) rather than a typed pointer, since with this flag the
C API returns an opaque cookie (e.g. struct page *), not a CPU pointer
to the allocated memory.

Only the DMA bus address is exposed to drivers; the opaque handle is
used solely to free the allocation on drop.

This commit is for reference only; there is currently no in-tree user.

Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Link: https://patch.msgid.link/20260321172749.592387-2-dakr@kernel.org
[acourbot: fix conflict in dma.rs.]
Signed-off-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add CoherentHandle, an opaque DMA allocation type for buffers that are
only ever accessed by hardware. Unlike Coherent&lt;T&gt;, it does not provide
CPU access to the allocated memory.

CoherentHandle implicitly sets DMA_ATTR_NO_KERNEL_MAPPING and stores the
value returned by dma_alloc_attrs() as an opaque handle
(NonNull&lt;c_void&gt;) rather than a typed pointer, since with this flag the
C API returns an opaque cookie (e.g. struct page *), not a CPU pointer
to the allocated memory.

Only the DMA bus address is exposed to drivers; the opaque handle is
used solely to free the allocation on drop.

This commit is for reference only; there is currently no in-tree user.

Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Link: https://patch.msgid.link/20260321172749.592387-2-dakr@kernel.org
[acourbot: fix conflict in dma.rs.]
Signed-off-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: dma: remove DMA_ATTR_NO_KERNEL_MAPPING from public attrs</title>
<updated>2026-03-28T13:07:31+00:00</updated>
<author>
<name>Danilo Krummrich</name>
<email>dakr@kernel.org</email>
</author>
<published>2026-03-21T17:27:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=18fb5f1f0289b8217c0c43d54d12bccc201dd640'/>
<id>18fb5f1f0289b8217c0c43d54d12bccc201dd640</id>
<content type='text'>
When DMA_ATTR_NO_KERNEL_MAPPING is passed to dma_alloc_attrs(), the
returned CPU address is not a pointer to the allocated memory but an
opaque handle (e.g. struct page *).

Coherent&lt;T&gt; (or CoherentAllocation&lt;T&gt; respectively) stores this value as
NonNull&lt;T&gt; and exposes methods that dereference it and even modify its
contents.

Remove the flag from the public attrs module such that drivers cannot
pass it to Coherent&lt;T&gt; (or CoherentAllocation&lt;T&gt; respectively) in the
first place.

Instead DMA_ATTR_NO_KERNEL_MAPPING can be supported with an additional
opaque type (e.g. CoherentHandle) which does not provide access to the
allocated memory.

Cc: stable@vger.kernel.org
Fixes: ad2907b4e308 ("rust: add dma coherent allocator abstraction")
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Reviewed-by: Gary Guo &lt;gary@garyguo.net&gt;
Link: https://patch.msgid.link/20260321172749.592387-1-dakr@kernel.org
Signed-off-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When DMA_ATTR_NO_KERNEL_MAPPING is passed to dma_alloc_attrs(), the
returned CPU address is not a pointer to the allocated memory but an
opaque handle (e.g. struct page *).

Coherent&lt;T&gt; (or CoherentAllocation&lt;T&gt; respectively) stores this value as
NonNull&lt;T&gt; and exposes methods that dereference it and even modify its
contents.

Remove the flag from the public attrs module such that drivers cannot
pass it to Coherent&lt;T&gt; (or CoherentAllocation&lt;T&gt; respectively) in the
first place.

Instead DMA_ATTR_NO_KERNEL_MAPPING can be supported with an additional
opaque type (e.g. CoherentHandle) which does not provide access to the
allocated memory.

Cc: stable@vger.kernel.org
Fixes: ad2907b4e308 ("rust: add dma coherent allocator abstraction")
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Reviewed-by: Gary Guo &lt;gary@garyguo.net&gt;
Link: https://patch.msgid.link/20260321172749.592387-1-dakr@kernel.org
Signed-off-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: dma: generalize BinaryWriter impl for Coherent&lt;T&gt;</title>
<updated>2026-03-27T20:48:18+00:00</updated>
<author>
<name>Danilo Krummrich</name>
<email>dakr@kernel.org</email>
</author>
<published>2026-03-25T00:39:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d1619a433806c61d240a1eb9b4f03cb33ac40fce'/>
<id>d1619a433806c61d240a1eb9b4f03cb33ac40fce</id>
<content type='text'>
Generalize the BinaryWriter implementation from Coherent&lt;[u8]&gt; to
Coherent&lt;T&gt; where T: KnownSize + AsBytes + ?Sized. The implementation
only uses size() and write_dma(), neither of which depends on the
inner type being a byte slice.

This allows any Coherent allocation with an AsBytes inner type to be
exposed as a debugfs binary file.

Acked-by: Gary Guo &lt;gary@garyguo.net&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Link: https://patch.msgid.link/20260325003921.3420-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Generalize the BinaryWriter implementation from Coherent&lt;[u8]&gt; to
Coherent&lt;T&gt; where T: KnownSize + AsBytes + ?Sized. The implementation
only uses size() and write_dma(), neither of which depends on the
inner type being a byte slice.

This allows any Coherent allocation with an AsBytes inner type to be
exposed as a debugfs binary file.

Acked-by: Gary Guo &lt;gary@garyguo.net&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Link: https://patch.msgid.link/20260325003921.3420-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: dma: implement BinaryWriter for Coherent&lt;[u8]&gt;</title>
<updated>2026-03-25T00:24:11+00:00</updated>
<author>
<name>Timur Tabi</name>
<email>ttabi@nvidia.com</email>
</author>
<published>2026-03-19T21:26:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=01681851393642e10b5cc3f35eb6a1916ee4aff1'/>
<id>01681851393642e10b5cc3f35eb6a1916ee4aff1</id>
<content type='text'>
Implement the BinaryWriter trait for Coherent&lt;[u8]&gt;, enabling DMA
coherent allocations to be exposed as readable binary files.  The
implementation handles offset tracking and bounds checking, copying data
from the coherent allocation to userspace via write_dma().

Signed-off-by: Timur Tabi &lt;ttabi@nvidia.com&gt;
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Tested-by: John Hubbard &lt;jhubbard@nvidia.com&gt;
Tested-by: Eliot Courtney &lt;ecourtney@nvidia.com&gt;
Link: https://patch.msgid.link/20260319212658.2541610-4-ttabi@nvidia.com
[ Rebase onto Coherent&lt;T&gt; changes. - Danilo ]
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Implement the BinaryWriter trait for Coherent&lt;[u8]&gt;, enabling DMA
coherent allocations to be exposed as readable binary files.  The
implementation handles offset tracking and bounds checking, copying data
from the coherent allocation to userspace via write_dma().

Signed-off-by: Timur Tabi &lt;ttabi@nvidia.com&gt;
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Tested-by: John Hubbard &lt;jhubbard@nvidia.com&gt;
Tested-by: Eliot Courtney &lt;ecourtney@nvidia.com&gt;
Link: https://patch.msgid.link/20260319212658.2541610-4-ttabi@nvidia.com
[ Rebase onto Coherent&lt;T&gt; changes. - Danilo ]
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
