linux.git/drivers/amba, branch v6.18.21 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git amba: tegra-ahb: Fix device leak on SMMU enable 2026-01-02T11:57:28+00:00 Johan Hovold johan@kernel.org 2025-09-25T15:00:07+00:00 1d18fb5c71f63c761e426ce8e73e750c6a891ac8 commit 500e1368e46928f4b2259612dcabb6999afae2a6 upstream. Make sure to drop the reference taken to the AHB platform device when looking up its driver data while enabling the SMMU. Note that holding a reference to a device does not prevent its driver data from going away. Fixes: 89c788bab1f0 ("ARM: tegra: Add SMMU enabler in AHB") Cc: stable@vger.kernel.org # 3.5 Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 500e1368e46928f4b2259612dcabb6999afae2a6 upstream.

Make sure to drop the reference taken to the AHB platform device when
looking up its driver data while enabling the SMMU.

Note that holding a reference to a device does not prevent its driver
data from going away.

Fixes: 89c788bab1f0 ("ARM: tegra: Add SMMU enabler in AHB")
Cc: stable@vger.kernel.org	# 3.5
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PM: domains: Add flags to specify power on attach/detach 2025-07-07T18:41:20+00:00 Claudiu Beznea claudiu.beznea.uj@bp.renesas.com 2025-07-03T11:27:06+00:00 d42c7c6fd66a6e2a78ae1da666c5df6c2fde8389 Calling dev_pm_domain_attach()/dev_pm_domain_detach() in bus driver probe/remove functions can affect system behavior when the drivers attached to the bus use devres-managed resources. Since devres actions may need to access device registers, calling dev_pm_domain_detach() too early, i.e., before these actions complete, can cause failures on some systems. One such example is Renesas RZ/G3S SoC-based platforms. If the device clocks are managed via PM domains, invoking dev_pm_domain_detach() in the bus driver's remove function removes the device's clocks from the PM domain, preventing any subsequent pm_runtime_resume*() calls from enabling those clocks. The second argument of dev_pm_domain_attach() specifies whether the PM domain should be powered on during attachment. Likewise, the second argument of dev_pm_domain_detach() indicates whether the domain should be powered off during detachment. Upcoming changes address the issue described above (initially for the platform bus only) by deferring the call to dev_pm_domain_detach() until after devres_release_all() in device_unbind_cleanup(). The detach_power_off field in struct dev_pm_info stores the detach power off info from the second argument of dev_pm_domain_attach(). Because there are cases where the device's PM domain power-on/off behavior must be conditional (e.g., in i2c_device_probe()), the patch introduces PD_FLAG_ATTACH_POWER_ON and PD_FLAG_DETACH_POWER_OFF flags to be passed to dev_pm_domain_attach(). Finally, dev_pm_domain_attach() and its users are updated to use the newly introduced PD_FLAG_ATTACH_POWER_ON and PD_FLAG_DETACH_POWER_OFF macros. This change is preparatory. Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com> # I2C Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Link: https://patch.msgid.link/20250703112708.1621607-2-claudiu.beznea.uj@bp.renesas.com [ rjw: Changelog adjustments ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Calling dev_pm_domain_attach()/dev_pm_domain_detach() in bus driver
probe/remove functions can affect system behavior when the drivers
attached to the bus use devres-managed resources. Since devres actions
may need to access device registers, calling dev_pm_domain_detach() too
early, i.e., before these actions complete, can cause failures on some
systems. One such example is Renesas RZ/G3S SoC-based platforms.

If the device clocks are managed via PM domains, invoking
dev_pm_domain_detach() in the bus driver's remove function removes the
device's clocks from the PM domain, preventing any subsequent
pm_runtime_resume*() calls from enabling those clocks.

The second argument of dev_pm_domain_attach() specifies whether the PM
domain should be powered on during attachment. Likewise, the second
argument of dev_pm_domain_detach() indicates whether the domain should be
powered off during detachment.

Upcoming changes address the issue described above (initially for the
platform bus only) by deferring the call to dev_pm_domain_detach() until
after devres_release_all() in device_unbind_cleanup(). The detach_power_off
field in struct dev_pm_info stores the detach power off info from the
second argument of dev_pm_domain_attach().

Because there are cases where the device's PM domain power-on/off behavior
must be conditional (e.g., in i2c_device_probe()), the patch introduces
PD_FLAG_ATTACH_POWER_ON and PD_FLAG_DETACH_POWER_OFF flags to be passed
to dev_pm_domain_attach().

Finally, dev_pm_domain_attach() and its users are updated to use the newly
introduced PD_FLAG_ATTACH_POWER_ON and PD_FLAG_DETACH_POWER_OFF macros.

This change is preparatory.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com> # I2C
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/20250703112708.1621607-2-claudiu.beznea.uj@bp.renesas.com
[ rjw: Changelog adjustments ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
iommu: Get DT/ACPI parsing into the proper probe path 2025-03-11T13:05:43+00:00 Robin Murphy robin.murphy@arm.com 2025-02-28T15:46:33+00:00 bcb81ac6ae3c2ef95b44e7b54c3c9522364a245c In hindsight, there were some crucial subtleties overlooked when moving {of,acpi}_dma_configure() to driver probe time to allow waiting for IOMMU drivers with -EPROBE_DEFER, and these have become an ever-increasing source of problems. The IOMMU API has some fundamental assumptions that iommu_probe_device() is called for every device added to the system, in the order in which they are added. Calling it in a random order or not at all dependent on driver binding leads to malformed groups, a potential lack of isolation for devices with no driver, and all manner of unexpected concurrency and race conditions. We've attempted to mitigate the latter with point-fix bodges like iommu_probe_device_lock, but it's a losing battle and the time has come to bite the bullet and address the true source of the problem instead. The crux of the matter is that the firmware parsing actually serves two distinct purposes; one is identifying the IOMMU instance associated with a device so we can check its availability, the second is actually telling that instance about the relevant firmware-provided data for the device. However the latter also depends on the former, and at the time there was no good place to defer and retry that separately from the availability check we also wanted for client driver probe. Nowadays, though, we have a proper notion of multiple IOMMU instances in the core API itself, and each one gets a chance to probe its own devices upon registration, so we can finally make that work as intended for DT/IORT/VIOT platforms too. All we need is for iommu_probe_device() to be able to run the iommu_fwspec machinery currently buried deep in the wrong end of {of,acpi}_dma_configure(). Luckily it turns out to be surprisingly straightforward to bootstrap this transformation by pretty much just calling the same path twice. At client driver probe time, dev->driver is obviously set; conversely at device_add(), or a subsequent bus_iommu_probe(), any device waiting for an IOMMU really should *not* have a driver already, so we can use that as a condition to disambiguate the two cases, and avoid recursing back into the IOMMU core at the wrong times. Obviously this isn't the nicest thing, but for now it gives us a functional baseline to then unpick the layers in between without many more awkward cross-subsystem patches. There are some minor side-effects like dma_range_map potentially being created earlier, and some debug prints being repeated, but these aren't significantly detrimental. Let's make things work first, then deal with making them nice. With the basic flow finally in the right order again, the next step is probably turning the bus->dma_configure paths inside-out, since all we really need from bus code is its notion of which device and input ID(s) to parse the common firmware properties with... Acked-by: Bjorn Helgaas <bhelgaas@google.com> # pci-driver.c Acked-by: Rob Herring (Arm) <robh@kernel.org> # of/device.c Signed-off-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Lorenzo Pieralisi <lpieralisi@kernel.org> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/e3b191e6fd6ca9a1e84c5e5e40044faf97abb874.1740753261.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel <jroedel@suse.de> 
In hindsight, there were some crucial subtleties overlooked when moving
{of,acpi}_dma_configure() to driver probe time to allow waiting for
IOMMU drivers with -EPROBE_DEFER, and these have become an
ever-increasing source of problems. The IOMMU API has some fundamental
assumptions that iommu_probe_device() is called for every device added
to the system, in the order in which they are added. Calling it in a
random order or not at all dependent on driver binding leads to
malformed groups, a potential lack of isolation for devices with no
driver, and all manner of unexpected concurrency and race conditions.
We've attempted to mitigate the latter with point-fix bodges like
iommu_probe_device_lock, but it's a losing battle and the time has come
to bite the bullet and address the true source of the problem instead.

The crux of the matter is that the firmware parsing actually serves two
distinct purposes; one is identifying the IOMMU instance associated with
a device so we can check its availability, the second is actually
telling that instance about the relevant firmware-provided data for the
device. However the latter also depends on the former, and at the time
there was no good place to defer and retry that separately from the
availability check we also wanted for client driver probe.

Nowadays, though, we have a proper notion of multiple IOMMU instances in
the core API itself, and each one gets a chance to probe its own devices
upon registration, so we can finally make that work as intended for
DT/IORT/VIOT platforms too. All we need is for iommu_probe_device() to
be able to run the iommu_fwspec machinery currently buried deep in the
wrong end of {of,acpi}_dma_configure(). Luckily it turns out to be
surprisingly straightforward to bootstrap this transformation by pretty
much just calling the same path twice. At client driver probe time,
dev->driver is obviously set; conversely at device_add(), or a
subsequent bus_iommu_probe(), any device waiting for an IOMMU really
should *not* have a driver already, so we can use that as a condition to
disambiguate the two cases, and avoid recursing back into the IOMMU core
at the wrong times.

Obviously this isn't the nicest thing, but for now it gives us a
functional baseline to then unpick the layers in between without many
more awkward cross-subsystem patches. There are some minor side-effects
like dma_range_map potentially being created earlier, and some debug
prints being repeated, but these aren't significantly detrimental. Let's
make things work first, then deal with making them nice.

With the basic flow finally in the right order again, the next step is
probably turning the bus->dma_configure paths inside-out, since all we
really need from bus code is its notion of which device and input ID(s)
to parse the common firmware properties with...

Acked-by: Bjorn Helgaas <bhelgaas@google.com> # pci-driver.c
Acked-by: Rob Herring (Arm) <robh@kernel.org> # of/device.c
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/e3b191e6fd6ca9a1e84c5e5e40044faf97abb874.1740753261.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
ARM: 9415/1: amba: Add dev_is_amba() function and export it for modules 2024-11-12T16:41:45+00:00 Kunwu Chan chentao@kylinos.cn 2024-09-02T06:39:20+00:00 ad8d1e323dd37f91d0c973e2a74c7b9054219adc Add dev_is_amba() function to determine whether the device is a AMBA device. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Kunwu Chan <chentao@kylinos.cn> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> 
Add dev_is_amba() function to determine
whether the device is a AMBA device.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
ARM: 9416/1: amba: make amba_bustype constant 2024-09-04T14:01:17+00:00 Kunwu Chan chentao@kylinos.cn 2024-09-02T06:43:23+00:00 a4d398a573d0f0c98c39d4af1866a3edaec4959c Since commit d492cc2573a0 ("driver core: device.h: make struct bus_type a const *"), the driver core can properly handle constant struct bus_type, move the amba_bustype variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kunwu Chan <chentao@kylinos.cn> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> 
Since commit d492cc2573a0 ("driver core: device.h: make struct
bus_type a const *"), the driver core can properly handle constant
struct bus_type, move the amba_bustype variable to be a constant
structure as well, placing it into read-only memory which can not be
modified at runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
driver core: have match() callback in struct bus_type take a const * 2024-07-03T13:16:54+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2024-07-01T12:07:37+00:00 d69d804845985c29ab5be5a4b3b1f4787893daf8 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> 
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>
ARM: 9361/1: amba: store owner from modules with amba_driver_register() 2024-04-18T11:09:14+00:00 Krzysztof Kozlowski k.kozlowski@samsung.com 2024-04-02T09:51:08+00:00 5677b17c33246fb69ecc250d493c635500b78980 Modules registering driver with amba_driver_register() often forget to set .owner field. The field is used by some of other kernel parts for reference counting (try_module_get()), so it is expected that drivers will set it. Solve the problem by moving this task away from the drivers to the core amba bus code, just like we did for platform_driver in commit 9447057eaff8 ("platform_device: use a macro instead of platform_driver_register"). Link: https://lore.kernel.org/r/20240326-module-owner-amba-v1-1-4517b091385b@linaro.org Reviewed-by: Andi Shyti <andi.shyti@kernel.org> Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> 
Modules registering driver with amba_driver_register() often forget to
set .owner field.  The field is used by some of other kernel parts for
reference counting (try_module_get()), so it is expected that drivers
will set it.

Solve the problem by moving this task away from the drivers to the core
amba bus code, just like we did for platform_driver in
commit 9447057eaff8 ("platform_device: use a macro instead of
platform_driver_register").

Link: https://lore.kernel.org/r/20240326-module-owner-amba-v1-1-4517b091385b@linaro.org

Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
amba: bus: balance firmware node reference counting 2023-10-17T18:37:35+00:00 Andy Shevchenko andriy.shevchenko@linux.intel.com 2023-10-06T14:57:31+00:00 ca5a75df36dd54fd7ca470a74581ef1d27edaaab Currently the ACPI code doesn't bump the reference count of the firmware node, while OF counter part does. Not that it's a problem right now, since ACPI doesn't really use the reference counting for firmware nodes, it still makes sense to make code robust against any changes done there. For this, - switch ACPI case to use device_set_node() to be unified with OF - move reference counting to amba_device_add() - switch to use firmware nodes instead of OF ones In the result we will have reference counting done in the same module for all callers independently on the nature of firmware node behind. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20231006145732.3419115-1-andriy.shevchenko@linux.intel.com Signed-off-by: Rob Herring <robh@kernel.org> 
Currently the ACPI code doesn't bump the reference count of
the firmware node, while OF counter part does. Not that it's
a problem right now, since ACPI doesn't really use the reference
counting for firmware nodes, it still makes sense to make code
robust against any changes done there. For this,
 - switch ACPI case to use device_set_node() to be unified with OF
 - move reference counting to amba_device_add()
 - switch to use firmware nodes instead of OF ones

In the result we will have reference counting done in the same module
for all callers independently on the nature of firmware node behind.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20231006145732.3419115-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Rob Herring <robh@kernel.org>
amba: bus: fix refcount leak 2023-08-22T13:50:57+00:00 Peng Fan peng.fan@nxp.com 2023-08-21T02:39:27+00:00 e312cbdc11305568554a9e18a2ea5c2492c183f3 commit 5de1540b7bc4 ("drivers/amba: create devices from device tree") increases the refcount of of_node, but not releases it in amba_device_release, so there is refcount leak. By using of_node_put to avoid refcount leak. Fixes: 5de1540b7bc4 ("drivers/amba: create devices from device tree") Signed-off-by: Peng Fan <peng.fan@nxp.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230821023928.3324283-1-peng.fan@oss.nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5de1540b7bc4 ("drivers/amba: create devices from device tree")
increases the refcount of of_node, but not releases it in
amba_device_release, so there is refcount leak. By using of_node_put
to avoid refcount leak.

Fixes: 5de1540b7bc4 ("drivers/amba: create devices from device tree")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230821023928.3324283-1-peng.fan@oss.nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: tegra: Remove MODULE_LICENSE in non-modules 2023-04-05T13:03:17+00:00 Nick Alcock nick.alcock@oracle.com 2023-02-17T14:10:44+00:00 e8476011f04b1ee4360f755ed19cbbddf12dc83e Since commit 8b41fc4454e ("kbuild: create modules.builtin without Makefile.modbuiltin or tristate.conf"), MODULE_LICENSE declarations are used to identify modules. As a consequence, uses of the macro in non-modules will cause modprobe to misidentify their containing object file as a module when it is not (false positives), and modprobe might succeed rather than failing with a suitable error message. So remove it in the files in this commit, none of which can be built as modules. Signed-off-by: Nick Alcock <nick.alcock@oracle.com> Suggested-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: linux-modules@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: linux-tegra@vger.kernel.org Signed-off-by: Thierry Reding <treding@nvidia.com> 
Since commit 8b41fc4454e ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf"), MODULE_LICENSE declarations
are used to identify modules. As a consequence, uses of the macro
in non-modules will cause modprobe to misidentify their containing
object file as a module when it is not (false positives), and modprobe
might succeed rather than failing with a suitable error message.

So remove it in the files in this commit, none of which can be built as
modules.

Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Suggested-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: linux-modules@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: linux-tegra@vger.kernel.org
Signed-off-by: Thierry Reding <treding@nvidia.com>