Since commit d492cc2573 ("driver core: device.h: make struct
bus_type a const *"), the driver core can properly handle constant
struct bus_type, move the host1x_context_device_bus_type 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: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240823080724.148423-1-kunwu.chan@linux.dev
Conditional registration is a problem for other subsystems which may
unwittingly try to interact with host1x_context_device_bus_type in an
uninitialised state on non-Tegra platforms. A look under /sys/bus on a
typical system already reveals plenty of entries from enabled but
otherwise irrelevant configs, so lets keep things simple and register
our context bus unconditionally too.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
The context bus is a "dummy" bus that contains struct devices that
correspond to IOMMU contexts assigned through Host1x to processes.
Even when host1x itself is built as a module, the bus is registered
in built-in code so that the built-in ARM SMMU driver is able to
reference it.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
