After device_initialize(), the embedded struct device in struct
host1x_device should be released through the device core with
put_device().

In host1x_device_add(), if host1x_device_parse_dt() fails, the current
error path frees the object directly with kfree(device). That bypasses
the normal device lifetime handling and leaks the reference held on the
embedded struct device.

The issue was identified by a static analysis tool I developed and
confirmed by manual review.

Fix this by using put_device() in the host1x_device_parse_dt() failure
path.

Fixes: f4c5cf88fbd50 ("gpu: host1x: Provide a proper struct bus_type")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Acked-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260413141526.2961841-1-lgs201920130244@gmail.com

In host1x_device_init(), the error teardown paths do not check
client->ops before dereferencing it, unlike the forward init paths
which correctly guard with 'client->ops &&'. This can result in a
NULL pointer dereference if client->ops is NULL.

Fix by adding the missing client->ops check in both the teardown
and teardown_late labels.

Signed-off-by: shayderrr <darknessshayder@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260517170456.84927-1-darknessshayder@gmail.com

When a buffer object is pinned via host1x_bo_pin() with a cache, the
resulting mapping is kept in the cache so it can be reused on subsequent
pins. Each mapping held a reference to the underlying host1x_bo (taken
in tegra_bo_pin / gather_bo_pin), so as long as a mapping was cached,
the bo itself could not be freed.

However, the only way to remove the cached mapping was through the free
path of the buffer object. This meant that if a bo got cached, it could
never get freed again.

Resolve the circularity by holding a weak reference to the bo from the
cache side. This is done by having the .pin callbacks not bump the bo's
refcount -- instead the common Host1x bo code does so, except for the
cache reference.

Also move the remove-cache-mapping-on-free code into a common function
inside Host1x code. This is only called from the TegraDRM GEM buffers
since those are the only ones that can be cached at the moment.

Reported-by: Aaron Kling <webgeek1234@gmail.com>
Fixes: 1f39b1dfa53c ("drm/tegra: Implement buffer object cache")
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Tested-by: Aaron Kling <webgeek1234@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260515-host1x-bocache-leak-v1-1-a0375f68aeab@nvidia.com

This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>

The callbacks .probe(), .remove() and .shutdown() for device_drivers
should go away. So migrate to bus methods. There are two differences
that need addressing:

 - The bus remove callback returns void while the driver remove callback
   returns int (the actual value is ignored by the core).
 - The bus shutdown callback is also called for unbound devices, so an
   additional check for dev->driver != NULL is needed.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # tegra20 tegra-video
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/dd55d034c68953268ea416aa5c13e41b158fcbb4.1765355236.git.u.kleine-koenig@baylibre.com

The return value of struct device_driver::remove is ignored by the core
(see device_remove() in drivers/base/dd.c). So it doesn't make sense to
let the host1x remove callback return an int just to ignore it later.

So make the callback return void. All current implementors return 0, so
they are easily converted.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # tegra20 tegra-video
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/d364fd4ec043d36ee12e46eaef98c57658884f63.1765355236.git.u.kleine-koenig@baylibre.com

Add support to register host1x devices without requiring subdevices.
This ensures syncpoint functionality remains available even when engine
subdevices are not present.

Add softdep for tegra-drm to make userspace interface available
without module autoloading through device tree entries.

Signed-off-by: Vamsee Vardhan Thummala <vthummala@nvidia.com>
[mperttunen@nvidia.com: some rewording]
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20250708-host1x-allow-no-subdevs-v1-1-93c66c251f03@nvidia.com

Avoids the need for manual cleanup of_node_put() in early exits
from the loop.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20240830073824.3539690-1-ruanjinjie@huawei.com

In the match() callback, the struct device_driver * should not be
changed, so change the function callback to be a const *.  This is one
step of many towards making the driver core safe to have struct
device_driver in read-only memory.

Because the match() callback is in all busses, all busses are modified
to handle this properly.  This does entail switching some container_of()
calls to container_of_const() to properly handle the constant *.

For some busses, like PCI and USB and HV, the const * is cast away in
the match callback as those busses do want to modify those structures at
this point in time (they have a local lock in the driver structure.)
That will have to be changed in the future if they wish to have their
struct device * in read-only-memory.

Cc: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Alex Elder <elder@kernel.org>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>