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From: Bartosz Golaszewski <>
To: Jonathan Cameron <>,
	Hartmut Knaack <>,
	Lars-Peter Clausen <>,
	Peter Meerwald-Stadler <>,
	Michal Simek <>,
	Greg Kroah-Hartman <>,
	Guenter Roeck <>,
	Andy Shevchenko <>
	Bartosz Golaszewski <>
Subject: [PATCH v6 0/3] devres: provide and use devm_krealloc()
Date: Sun,  2 Aug 2020 10:34:55 +0200
Message-ID: <> (raw)

From: Bartosz Golaszewski <>

Hi Greg, Andy,

this is a reworked version of devm_krealloc(). This time without the risk
of sleeping with spinlock taken. I noticed that devres_lock is only there
to protect the integrity of the devres list - we can assume users are sane
enough to not devm_kfree() chunks that they devm_krealloc() at the same time
so we only take the lock when manipulating the list now.

I dropped Andy's review tag due to this change.


Regular krealloc() obviously can't work with managed memory. This series
implements devm_krealloc() and adds the first users with hope that this
helper will be adopted by other drivers currently using non-managed

Some additional changes to the code modified by main patches are included.

v1 -> v2:
- remove leftover call to hwmon_device_unregister() from pmbus_core.c
- add a patch extending devm_kmalloc() to handle zero size case
- use WARN_ON() instead of WARN_ONCE() in devm_krealloc() when passed
  a pointer to non-managed memory
- correctly handle the case when devm_krealloc() is passed a pointer to
  memory in .rodata (potentially returned by devm_kstrdup_const())
- correctly handle ZERO_SIZE_PTR passed as the ptr argument in devm_krealloc()

v2 -> v3:
- drop already applied patches
- collect Acks
- add an additional user in iio

v3 -> v4:
- add the kerneldoc for devm_krealloc()
- WARN() outside of spinlock
- rename local variable

v4 -> v5:
- tweak the kerneldoc

v5 -> v6:
- tweak the devres_lock handling in devm_krealloc()

Bartosz Golaszewski (3):
  devres: provide devm_krealloc()
  hwmon: pmbus: use more devres helpers
  iio: adc: xilinx-xadc: use devm_krealloc()

 .../driver-api/driver-model/devres.rst        |  1 +
 drivers/base/devres.c                         | 65 +++++++++++++++++++
 drivers/hwmon/pmbus/pmbus_core.c              | 28 +++-----
 drivers/iio/adc/xilinx-xadc-core.c            | 16 ++---
 include/linux/device.h                        |  2 +
 5 files changed, 85 insertions(+), 27 deletions(-)


             reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-02  8:34 Bartosz Golaszewski [this message]
2020-08-02  8:34 ` [PATCH v6 1/3] devres: provide devm_krealloc() Bartosz Golaszewski
2020-08-02 10:42   ` Andy Shevchenko
2020-08-03 19:31     ` Bartosz Golaszewski
2020-08-02  8:34 ` [PATCH v6 2/3] hwmon: pmbus: use more devres helpers Bartosz Golaszewski
2020-08-02  8:34 ` [PATCH v6 3/3] iio: adc: xilinx-xadc: use devm_krealloc() Bartosz Golaszewski

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