linux-toradex.git/drivers/char/xillybus, branch master

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using

    git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

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

char: xillybus: add WQ_UNBOUND to alloc_workqueue users

2025-11-26T14:09:43+00:00

Currently if a user enqueues a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistency cannot be addressed without refactoring the API.

alloc_workqueue() treats all queues as per-CPU by default, while unbound
workqueues must opt-in via WQ_UNBOUND.

This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.

This continues the effort to refactor workqueue APIs, which began with
the introduction of new workqueues and a new alloc_workqueue flag in:

commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq")
commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag")

This change adds the WQ_UNBOUND flag to explicitly request
alloc_workqueue() to be unbound, because this specific workload has no
benefit being per-cpu.

With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU.

Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit default.

Suggested-by: Tejun Heo 
Signed-off-by: Marco Crivellari 
Acked-by: Eli Billauer 
Link: https://patch.msgid.link/20251107163755.356187-1-marco.crivellari@suse.com
Signed-off-by: Greg Kroah-Hartman

char: xillybus: Use to_delayed_work()

2025-04-17T08:56:11+00:00

Use to_delayed_work() instead of open-coding it.

Signed-off-by: Chen Ni 
Acked-by: Eli Billauer 
Link: https://lore.kernel.org/r/20250414074559.3954142-1-nichen@iscas.ac.cn
Signed-off-by: Greg Kroah-Hartman

char: Switch back to struct platform_driver::remove()

2024-11-05T04:33:47+00:00

After commit 0edb555a65d1 ("platform: Make platform_driver::remove()
return void") .remove() is (again) the right callback to implement for
platform drivers.

Convert all platform drivers matched by the "CHAR and MISC DRIVERS"
maintainer's entry to use .remove(), with the eventual goal to drop
struct platform_driver::remove_new(). As .remove() and .remove_new()
have the same prototypes, conversion is done by just changing the
structure member name in the driver initializer.

Signed-off-by: Uwe Kleine-König 
Acked-by: Eli Billauer 
Link: https://lore.kernel.org/r/20241021104511.405661-2-u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman

char: xillybus: Check USB endpoints when probing device

2024-08-16T07:57:56+00:00

Ensure, as the driver probes the device, that all endpoints that the
driver may attempt to access exist and are of the correct type.

All XillyUSB devices must have a Bulk IN and Bulk OUT endpoint at
address 1. This is verified in xillyusb_setup_base_eps().

On top of that, a XillyUSB device may have additional Bulk OUT
endpoints. The information about these endpoints' addresses is deduced
from a data structure (the IDT) that the driver fetches from the device
while probing it. These endpoints are checked in setup_channels().

A XillyUSB device never has more than one IN endpoint, as all data
towards the host is multiplexed in this single Bulk IN endpoint. This is
why setup_channels() only checks OUT endpoints.

Reported-by: syzbot+eac39cba052f2e750dbe@syzkaller.appspotmail.com
Cc: stable 
Closes: https://lore.kernel.org/all/0000000000001d44a6061f7a54ee@google.com/T/
Fixes: a53d1202aef1 ("char: xillybus: Add driver for XillyUSB (Xillybus variant for USB)").
Signed-off-by: Eli Billauer 
Link: https://lore.kernel.org/r/20240816070200.50695-2-eli.billauer@gmail.com
Signed-off-by: Greg Kroah-Hartman

char: xillybus: Refine workqueue handling

2024-08-16T07:57:50+00:00

As the wakeup work item now runs on a separate workqueue, it needs to be
flushed separately along with flushing the device's workqueue.

Also, move the destroy_workqueue() call to the end of the exit method,
so that deinitialization is done in the opposite order of
initialization.

Fixes: ccbde4b128ef ("char: xillybus: Don't destroy workqueue from work item running on it")
Cc: stable 
Signed-off-by: Eli Billauer 
Link: https://lore.kernel.org/r/20240816070200.50695-1-eli.billauer@gmail.com
Signed-off-by: Greg Kroah-Hartman

char: xillybus: Don't destroy workqueue from work item running on it

2024-08-13T08:06:12+00:00

Triggered by a kref decrement, destroy_workqueue() may be called from
within a work item for destroying its own workqueue. This illegal
situation is averted by adding a module-global workqueue for exclusive
use of the offending work item. Other work items continue to be queued
on per-device workqueues to ensure performance.

Reported-by: syzbot+91dbdfecdd3287734d8e@syzkaller.appspotmail.com
Cc: stable 
Closes: https://lore.kernel.org/lkml/0000000000000ab25a061e1dfe9f@google.com/
Signed-off-by: Eli Billauer 
Link: https://lore.kernel.org/r/20240801121126.60183-1-eli.billauer@gmail.com
Signed-off-by: Greg Kroah-Hartman

char: xillybus: Convert to platform remove callback returning void

2024-03-07T21:49:30+00:00

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König 
Acked-by: Eli Billauer 
Link: https://lore.kernel.org/r/20240306175710.82569-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman

char: xillybus: make XILLYBUS_OF depend on HAS_IOMEM

2023-08-04T13:39:39+00:00

On s390 systems (aka mainframes), it has classic channel devices for
networking and permanent storage that are currently even more common
than PCI devices. Hence it could have a fully functional s390 kernel
with CONFIG_PCI=n, then the relevant iomem mapping functions
[including ioremap(), devm_ioremap(), etc.] are not available.

Here let XILLYBUS_OF depend on HAS_IOMEM so that it won't be built
to cause below compiling error if PCI is unset:

------
ERROR: modpost: "devm_platform_ioremap_resource" [drivers/char/xillybus/xillybus_of.ko] undefined!
------

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202306211329.ticOJCSv-lkp@intel.com/
Signed-off-by: Baoquan He 
Acked-by: Eli Billauer 
Cc: Arnd Bergmann 
Link: https://lore.kernel.org/r/20230707135852.24292-3-bhe@redhat.com
Signed-off-by: Greg Kroah-Hartman