Syncpoint fences are backed by a hardware syncpoint / threshold, which
various hardware is capable of waiting for directly without CPU
intervention. Add a function to allow drivers for such devices to
extract the details to allow programming the hardware accordingly.

The function also provides the host1x instance corresponding to the
syncpoint since a system may contain multiple instances of host1x with
separate sets of syncpoints.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260730-b4-host1x-syncobj-wait-v1-5-afa730410392@nvidia.com

Add kernel module parameter to allow disabling context stealing in cases
where reliability and consistency is preferred.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260710-b4-host1x-ctxsteal-v1-2-b1f8f6b37cc5@nvidia.com

Currently, each process holding an open TegraDRM channel reserves for
itself one of the limited number of hardware memory contexts. Attempting
to allocate a channel when all contexts are in use results in failure.

While we cannot have more contexts than the hardware supports in active
use, idle channels don't necessarily need to have a backing memory
context. As such, in this patch, we add another layer to allow hardware
memory contexts to be "stolen away" by channels that are in active use,
from idle processes.

The way this is implemented, is by keeping track of memory mappings on
each abstracted memory context. If we need to steal that memory
context's backing hardware context, we unmap everything from it and give
it away. When that abstracted memory context is needed again
(re-activated), we attempt to allocate or steal another hardware context
and re-map the previously unmapped buffers.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260710-b4-host1x-ctxsteal-v1-1-b1f8f6b37cc5@nvidia.com

Allow specifying usable channel, and allocatable syncpoint ranges
through the device tree. This is necessary when Host1x resources
are shared between multiple operating systems or independent hardware
units and Linux has limited access to them.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260702-host1x-nohv-v2-4-e6d88bac0af6@nvidia.com

Host1x can be used without access to the hypervisor or common regions
when they are configured by other components in the system. Add support
for running without access to them.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260702-host1x-nohv-v2-3-e6d88bac0af6@nvidia.com

Linux 7.2

There was a lot of conflicts this round between fixes and next,
and I'd like to get the merge resolutions that we have in drm-tip.

Signed-off-by: Dave Airlie <airlied@redhat.com>

Add device data and chip headers for Tegra264.

Signed-off-by: Santosh BS <santoshb@nvidia.com>
Co-developed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260622-t264-host1x-v2-4-ff7364d9ff7b@nvidia.com

The previous parsing of the iommu-map property assumed each context
device has its own one-length entry in the device tree. This has worked
fine so far, but on Tegra264 larger numbers of context devices are
usable, so it's better to support linear ranges as well.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260622-t264-host1x-v2-3-ff7364d9ff7b@nvidia.com

Host1x syncpoints are 32-bit counters that roll over by design.
To make that explicit in the code, use wrapping_* functions whenever
arithmetic is done on syncpoint values.

Atomic operations cannot be updated but a comment is added.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260609-b4-host1x-small-fixes-a-v1-6-7c1131c0b3ad@nvidia.com

pin_job() returns negative errno values on error paths (-EINVAL,
-ENOMEM, PTR_ERR() of mapping) but was declared as unsigned int.
The caller would immediately cast back to int, so there was no
functional issue, but it still warrants fixing.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260609-b4-host1x-small-fixes-a-v1-5-7c1131c0b3ad@nvidia.com