Both destination buffers are already zero-initialized, making strscpy()
sufficient for safely copying 'obj_type'. The additional NUL-padding
performed by strscpy_pad() is unnecessary.
If the destination buffer has a fixed length, strscpy() automatically
determines its size using sizeof() when the argument is omitted. This
makes the explicit size arguments unnecessary.
No functional changes intended.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20250429104149.66334-1-thorsten.blum@linux.dev
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Since it's not currently safe to take device_lock() in the IOMMU probe
path, that can race against really_probe() setting dev->driver before
attempting to bind. The race itself isn't so bad, since we're only
concerned with dereferencing dev->driver itself anyway, but sadly my
attempt to implement the check with minimal churn leads to a kind of
TOCTOU issue, where dev->driver becomes valid after to_fsl_mc_driver(NULL)
is already computed, and thus the check fails to work as intended.
Will and I both hit this with the platform bus, but the pattern here is
the same, so fix it for correctness too.
Reported-by: Will McVicker <willmcvicker@google.com>
Fixes: bcb81ac6ae ("iommu: Get DT/ACPI parsing into the proper probe path")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Will McVicker <willmcvicker@google.com>
Link: https://lore.kernel.org/r/20250425133929.646493-3-robin.murphy@arm.com
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
The fsl-mc bus associated to the root DPRC in a DPAA2 system exports a
device file for userspace access to the MC firmware. In case the DPRC's
local MC portal (DPMCP) is currently in use, a new DPMCP device is
allocated through the fsl_mc_portal_allocate() function.
In this case, the call to fsl_mc_portal_allocate() will fail with -EINVAL
when trying to add a device link between the root DPRC (consumer) and
the newly allocated DPMCP device (supplier). This is because the DPMCP
is a dependent of the DPRC device (the bus).
Fix this by not adding a device link in case the DPMCP is allocated for
the root DPRC's usage.
Fixes: afb7742281 ("bus: fsl-mc: automatically add a device_link on fsl_mc_[portal,object]_allocate")
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250408105814.2837951-3-ioana.ciornei@nxp.com
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
The blamed commit tried to simplify how the deallocations are done but,
in the process, introduced a double-free on the mc_dev variable.
In case the MC device is a DPRC, a new mc_bus is allocated and the
mc_dev variable is just a reference to one of its fields. In this
circumstance, on the error path only the mc_bus should be freed.
This commit introduces back the following checkpatch warning which is a
false-positive.
WARNING: kfree(NULL) is safe and this check is probably not required
+ if (mc_bus)
+ kfree(mc_bus);
Fixes: a042fbed02 ("staging: fsl-mc: simplify couple of deallocations")
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20250408105814.2837951-2-ioana.ciornei@nxp.com
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Pull more SoC driver updates from Arnd Bergmann:
"This is the promised follow-up to the soc drivers branch, adding minor
updates to omap and freescale drivers.
Most notably, Ioana Ciornei takes over maintenance of the DPAA bus
driver used in some NXP (originally Freescale) chips"
* tag 'soc-drivers-6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
bus: fsl-mc: Remove deadcode
MAINTAINERS: add the linuppc-dev list to the fsl-mc bus entry
MAINTAINERS: fix nonexistent dtbinding file name
MAINTAINERS: add myself as maintainer for the fsl-mc bus
irqdomain: soc: Switch to irq_find_mapping()
Input: tsc2007 - accept standard properties
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>
Constify the following API:
struct device *device_find_child(struct device *dev, void *data,
int (*match)(struct device *dev, void *data));
To :
struct device *device_find_child(struct device *dev, const void *data,
device_match_t match);
typedef int (*device_match_t)(struct device *dev, const void *data);
with the following reasons:
- Protect caller's match data @*data which is for comparison and lookup
and the API does not actually need to modify @*data.
- Make the API's parameters (@match)() and @data have the same type as
all of other device finding APIs (bus|class|driver)_find_device().
- All kinds of existing device match functions can be directly taken
as the API's argument, they were exported by driver core.
Constify the API and adapt for various existing usages.
BTW, various subsystem changes are squashed into this commit to meet
'git bisect' requirement, and this commit has the minimal and simplest
changes to complement squashing shortcoming, and that may bring extra
code improvement.
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Uwe Kleine-König <ukleinek@kernel.org> # for drivers/pwm
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-4-6623037414d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After commit 0edb555a65 ("platform: Make platform_driver::remove()
return void") .remove() is (again) the right callback to implement for
platform drivers.
Convert all platform drivers below drivers/bus 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 <u.kleine-koenig@baylibre.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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>
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. As fsl_mc_bus_remove() has the
same type now as fsl_mc_bus_shutdown() and the only thing the latter
does is to call the former, use fsl_mc_bus_remove() directly as
.shutdown() callback.
Link: https://lore.kernel.org/r/20231103230001.3652259-4-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
The mc that belongs to a pdev is always a root dprc. In
fsl_mc_bus_probe() the mc device gets assigned the platform device as
parent. As dev_is_fsl_mc() is false for a platform device,
fsl_mc_get_root_dprc() will always be true and so the if body is never
run and it can be dropped.
The motivation for this change is to get rid of an error path in
.remove() that is broken (because only a part of the necessary cleanup
is done resulting in leaks and/or use-after-frees and the driver core
ignores the return value of .remove().)
Link: https://lore.kernel.org/r/20231103230001.3652259-3-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Pull ARM SoC cleanups from Arnd Bergmann:
"These are all minor cleanups for platform specific code in arch/arm/
and some of the associated drivers. The majority of these are work
done by Rob Herring to improve the way devicetreee header files are
handled"
* tag 'soc-arm-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (49 commits)
ARM: davinci: Drop unused includes
ARM: s5pv210: Explicitly include correct DT includes
ARM: dove: Drop unused includes
ARM: mvebu: Explicitly include correct DT includes
Documentation/process: maintainer-soc: document dtbs_check requirement for Samsung
MAINTAINER: samsung: document dtbs_check requirement for Samsung
Documentation/process: maintainer-soc: add clean platforms profile
MAINTAINERS: soc: reference maintainer profile
ARM: nspire: Remove unused header file mmio.h
ARM: nspire: Use syscon-reboot to handle restart
soc: fsl: Explicitly include correct DT includes
soc: xilinx: Explicitly include correct DT includes
soc: sunxi: Explicitly include correct DT includes
soc: rockchip: Explicitly include correct DT includes
soc: mediatek: Explicitly include correct DT includes
soc: aspeed: Explicitly include correct DT includes
firmware: Explicitly include correct DT includes
bus: Explicitly include correct DT includes
ARM: spear: Explicitly include correct DT includes
ARM: mvebu: Explicitly include correct DT includes
...
Since commit 3d5089c426 ("of/address: Add support for 3 address cell
bus"), the DT address functions can handle translating buses with 3
address cells. Replace the custom code with the for_each_of_range()
iterator.
The original code had fallbacks to get "#address-cells"/"#size-cells"
from the bus parent node if they are missing. This is non-standard
behavior, and AFAICT the upstream .dts files never relied on that.
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Tested-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230823190958.2717267-1-robh@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20230803-dt-header-cleanups-for-soc-v2-16-d8de2cc88bff@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Pull Char/Misc updates from Greg KH:
"Here is the big set of char/misc and other driver subsystem updates
for 6.5-rc1.
Lots of different, tiny, stuff in here, from a range of smaller driver
subsystems, including pulls from some substems directly:
- IIO driver updates and additions
- W1 driver updates and fixes (and a new maintainer!)
- FPGA driver updates and fixes
- Counter driver updates
- Extcon driver updates
- Interconnect driver updates
- Coresight driver updates
- mfd tree tag merge needed for other updates on top of that, lots of
small driver updates as patches, including:
- static const updates for class structures
- nvmem driver updates
- pcmcia driver fix
- lots of other small driver updates and fixes
All of these have been in linux-next for a while with no reported
problems"
* tag 'char-misc-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (243 commits)
bsr: fix build problem with bsr_class static cleanup
comedi: make all 'class' structures const
char: xillybus: make xillybus_class a static const structure
xilinx_hwicap: make icap_class a static const structure
virtio_console: make port class a static const structure
ppdev: make ppdev_class a static const structure
char: misc: make misc_class a static const structure
/dev/mem: make mem_class a static const structure
char: lp: make lp_class a static const structure
dsp56k: make dsp56k_class a static const structure
bsr: make bsr_class a static const structure
oradax: make 'cl' a static const structure
hwtracing: hisi_ptt: Fix potential sleep in atomic context
hwtracing: hisi_ptt: Advertise PERF_PMU_CAP_NO_EXCLUDE for PTT PMU
hwtracing: hisi_ptt: Export available filters through sysfs
hwtracing: hisi_ptt: Add support for dynamically updating the filter list
hwtracing: hisi_ptt: Factor out filter allocation and release operation
samples: pfsm: add CC_CAN_LINK dependency
misc: fastrpc: check return value of devm_kasprintf()
coresight: dummy: Update type of mode parameter in dummy_{sink,source}_enable()
...
Fixes a clang compiler warning:
drivers/bus/fsl-mc/fsl-mc-allocator.c:565:6: warning: variable 'free_count' set but not used [-Wunused-but-set-variable]
int free_count = 0;
Fixes: d8e026a449 ("staging: fsl-mc: remove some superfluous WARN_ONs")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
The value returned by an fsl-mc driver's remove function is mostly
ignored. (Only an error message is printed if the value is non-zero
and then device removal continues unconditionally.)
So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # sanity checks
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Tested-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
Instead of silently returning an error in the remove callback (which yields
a generic and little informing error message), annotate each error path of
fsl_mc_resource_pool_remove_device() with an error message and return zero
in the remove callback to suppress the error message.
Note that changing the return value has no other effect than suppressing
the error message by the fsl_mc bus driver.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # sanity checks
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Tested-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
If fsl_mc_is_allocatable(mc_dev) evaluates to false, the driver won't
have bound to that device and then fsl_mc_allocator_remove() is never
called for that device. fsl_mc_allocator_remove() is the only caller of
fsl_mc_resource_pool_remove_device(), so the same check can be removed
from there.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # sanity checks
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Tested-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
The error message emitted in fsl_mc_driver_remove() is very generic.
Replace it by a message that mentions the reason for the failure.
Returning zero instead of a negative value has no side effect apart from
suppressing the generic error message.
The first if condition in dprc_remove() can never be true, as this would
prevent successful probing of the device and then .remove wasn't called.
So this can just be dropped.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # sanity checks
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Tested-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
If a platform driver's remove function returns an error code, this
results in a (generic and little helpful) error message. Otherwise the
value is ignored.
As fsl_mc_driver_remove() already emit an error message, return 0 also
in the error case. The only effect is to suppress the device core's
error message.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # sanity checks
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Tested-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
In fsl_mc_bus_remove(), mc->root_mc_bus_dev->mc_io is passed to
fsl_destroy_mc_io(). However, mc->root_mc_bus_dev is already freed in
fsl_mc_device_remove(). Then reference to mc->root_mc_bus_dev->mc_io
triggers KASAN use-after-free. To avoid the use-after-free, keep the
reference to mc->root_mc_bus_dev->mc_io in a local variable and pass to
fsl_destroy_mc_io().
This patch needs rework to apply to kernels older than v5.15.
Fixes: f93627146f ("staging: fsl-mc: fix asymmetry in destroy of mc_io")
Cc: stable@vger.kernel.org # v5.15+
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20220601105159.87752-1-shinichiro.kawasaki@wdc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull driver core updates from Greg KH:
"Here is the set of driver core changes for 5.19-rc1.
Lots of tiny driver core changes and cleanups happened this cycle, but
the two major things are:
- firmware_loader reorganization and additions including the ability
to have XZ compressed firmware images and the ability for userspace
to initiate the firmware load when it needs to, instead of being
always initiated by the kernel. FPGA devices specifically want this
ability to have their firmware changed over the lifetime of the
system boot, and this allows them to work without having to come up
with yet-another-custom-uapi interface for loading firmware for
them.
- physical location support added to sysfs so that devices that know
this information, can tell userspace where they are located in a
common way. Some ACPI devices already support this today, and more
bus types should support this in the future.
Smaller changes include:
- driver_override api cleanups and fixes
- error path cleanups and fixes
- get_abi script fixes
- deferred probe timeout changes.
It's that last change that I'm the most worried about. It has been
reported to cause boot problems for a number of systems, and I have a
tested patch series that resolves this issue. But I didn't get it
merged into my tree before 5.18-final came out, so it has not gotten
any linux-next testing.
I'll send the fixup patches (there are 2) as a follow-on series to this
pull request.
All have been tested in linux-next for weeks, with no reported issues
other than the above-mentioned boot time-outs"
* tag 'driver-core-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits)
driver core: fix deadlock in __device_attach
kernfs: Separate kernfs_pr_cont_buf and rename_lock.
topology: Remove unused cpu_cluster_mask()
driver core: Extend deferred probe timeout on driver registration
MAINTAINERS: add Russ Weight as a firmware loader maintainer
driver: base: fix UAF when driver_attach failed
test_firmware: fix end of loop test in upload_read_show()
driver core: location: Add "back" as a possible output for panel
driver core: location: Free struct acpi_pld_info *pld
driver core: Add "*" wildcard support to driver_async_probe cmdline param
driver core: location: Check for allocations failure
arch_topology: Trace the update thermal pressure
kernfs: Rename kernfs_put_open_node to kernfs_unlink_open_file.
export: fix string handling of namespace in EXPORT_SYMBOL_NS
rpmsg: use local 'dev' variable
rpmsg: Fix calling device_lock() on non-initialized device
firmware_loader: describe 'module' parameter of firmware_upload_register()
firmware_loader: Move definitions from sysfs_upload.h to sysfs.h
firmware_loader: Fix configs for sysfs split
selftests: firmware: Add firmware upload selftests
...
The devices on platform/amba/fsl-mc/PCI buses could be bound to drivers
with the device DMA managed by kernel drivers or user-space applications.
Unfortunately, multiple devices may be placed in the same IOMMU group
because they cannot be isolated from each other. The DMA on these devices
must either be entirely under kernel control or userspace control, never
a mixture. Otherwise the driver integrity is not guaranteed because they
could access each other through the peer-to-peer accesses which by-pass
the IOMMU protection.
This checks and sets the default DMA mode during driver binding, and
cleanups during driver unbinding. In the default mode, the device DMA is
managed by the device driver which handles DMA operations through the
kernel DMA APIs (see Documentation/core-api/dma-api.rst).
For cases where the devices are assigned for userspace control through the
userspace driver framework(i.e. VFIO), the drivers(for example, vfio_pci/
vfio_platfrom etc.) may set a new flag (driver_managed_dma) to skip this
default setting in the assumption that the drivers know what they are
doing with the device DMA.
Calling iommu_device_use_default_domain() before {of,acpi}_dma_configure
is currently a problem. As things stand, the IOMMU driver ignored the
initial iommu_probe_device() call when the device was added, since at
that point it had no fwspec yet. In this situation,
{of,acpi}_iommu_configure() are retriggering iommu_probe_device() after
the IOMMU driver has seen the firmware data via .of_xlate to learn that
it actually responsible for the given device. As the result, before
that gets fixed, iommu_use_default_domain() goes at the end, and calls
arch_teardown_dma_ops() if it fails.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Stuart Yoder <stuyoder@gmail.com>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20220418005000.897664-5-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Commit e8604b1447 introduced a call to the helper function
msi_first_desc(), which needs MSI descriptor mutex lock before
call. However, the required mutex lock was not added. This results in
lockdep assertion:
WARNING: CPU: 4 PID: 119 at kernel/irq/msi.c:274 msi_first_desc+0xd0/0x10c
msi_first_desc+0xd0/0x10c
fsl_mc_msi_domain_alloc_irqs+0x7c/0xc0
fsl_mc_populate_irq_pool+0x80/0x3cc
Fix this by adding the mutex lock and unlock around the function call.
Fixes: e8604b1447 ("bus: fsl-mc-msi: Simplify MSI descriptor handling")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220412075636.755454-1-shinichiro.kawasaki@wdc.com
