Files
linux-nvgpu/drivers/gpu/nvgpu/common/semaphore
Konsta Hölttä d916e85171 gpu: nvgpu: incr sync once submit is ready to go
Split out the max value increment and syncpt interrupt registration out
of nvgpu_channel_sync_incr*(). This API is called in the submit path to
prepare buffers and tracking resources, but later on in the submit path
errors can still occur so that the increment wouldn't happen (unless
artificially forced by sw).

The increment and irq registration cannot easily be undone and it makes
more sense to do these at the moment when the prepared job is finally
ready, so add a new nvgpu_channel_sync_mark_progress() API to be called
later in the submit path to signal that progress shall eventually happen
on the sync. Without this, the max value would stay too large after an
unsuccessful submit until the channel gets closed.

The sync object (syncpt or semaphore) is always exclusively owned by the
channel that allocated it, so nonatomically reading the max value first
in sync_incr() and incrementing it later in mark_progress() is racefree;
all submits per channel are serialized.

Change the channel syncpoint to client managed from host managed so that
nvhost-exported sync fences behave correctly with the temporary state
where the fence threshold is over the max value. Ideally we'd always
track nvgpu-owned syncpts' max values internally, but this is enough for
now.

Jira NVGPU-5491

Change-Id: Idf0bda7ac93d7f2f114cdeb497fe6b5369d21c95
Signed-off-by: Konsta Hölttä <kholtta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvgpu/+/2340465
Reviewed-by: automaticguardword <automaticguardword@nvidia.com>
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
2020-12-15 14:13:28 -06:00
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