gpu: host1x: Correct allocated size for contexts

Original implementation over allocates the memory size for the
contexts list. The size of memory for the contexts list is based
on the number of iommu groups specified in the device tree.

Fixes: 8aa5bcb61612 ("gpu: host1x: Add context device management code")
Signed-off-by: Johnny Liu <johnliu@nvidia.com>
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230901115910.701518-1-cyndis@kapsi.fi

gpu: host1x: Return error when context device not attached to IOMMU

If a context device was not attached to IOMMU, we kept the old
success err value causing context devices to be unregistered but
success to be returned. This would mean that things would go on
but with context isolation disabled.

To decide on an explicit behavior, let's return an error code
here instead. If someone wants to go without IOMMU on a platform
modern enough to support context isolation, they can remove the
context devices from device tree.

Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230413082202.114721-2-cyndis@kapsi.fi

gpu/host1x: Explicitly include correct DT includes

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>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230714174549.4056675-1-robh@kernel.org

gpu: host1x: Fix memory leak of device names

The device names allocated by dev_set_name() need be freed
before module unloading, but they can not be freed because
the kobject's refcount which was set in device_initialize()
has not be decreased to 0.

As comment of device_add() says, if it fails, use only
put_device() drop the refcount, then the name will be
freed in kobejct_cleanup().

device_del() and put_device() can be replaced with
device_unregister(), so call it to unregister the added
successfully devices, and just call put_device() to the
not added device.

Add a release() function to device to avoid null release()
function WARNING in device_release(), it's empty, because
the context devices are freed together in
host1x_memory_context_list_free().

Fixes: 8aa5bcb61612 ("gpu: host1x: Add context device management code")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Fix potential double free if IOMMU is disabled

If context device has no IOMMU, the 'cdl->devs' is freed in
error path, but host1x_memory_context_list_init() doesn't
return an error code, so the module can be loaded successfully,
when it's unloading, the host1x_memory_context_list_free() is
called in host1x_remove(), it will cause double free. Set the
'cdl->devs' to NULL after freeing it to avoid double free.

Fixes: 8aa5bcb61612 ("gpu: host1x: Add context device management code")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Use tegra_dev_iommu_get_stream_id()

Use the newly implemented tegra_dev_iommu_get_stream_id() helper to
encapsulate and centralize the IOMMU stream ID access.

Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Select context device based on attached IOMMU

On Tegra234, engines that are programmed through Host1x channels can
be attached to either the NISO0 or NISO1 SMMU. Because of that, when
selecting a context device to use with an engine, we need to select
one that is also attached to the same SMMU.

Add a parameter to host1x_memory_context_alloc to specify which device
we are allocating a context for, and use it to pick an appropriate
context device.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
[treding@nvidia.com: update !IOMMU_API stub signature]
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Add context device management code

Add code to register context devices from device tree, allocate them
out and manage their refcounts.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>