Commit 55f4139b authored by Srinivasan Shanmugam's avatar Srinivasan Shanmugam Committed by Alex Deucher
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drm/amd/amdgpu: Add Annotations to Process Isolation functions 



This update adds explanations to key functions that manage how the
Kernel Fusion Driver (KFD) and Kernel Graphics Driver (KGD) share the
GPU.

amdgpu_gfx_enforce_isolation_wait_for_kfd: Controls the waiting period
for KFD to ensure it takes turns with KGD in using the GPU. It uses a
mutex to safely manage shared data, like timing and state, and tracks
when KFD starts and stops waiting.

amdgpu_gfx_enforce_isolation_ring_begin_use: Ensures KFD has enough time
to run before new tasks are submitted to the GPU ring. It uses a mutex
to synchronize access and may adjust the KFD scheduler.

amdgpu_gfx_enforce_isolation_ring_end_use: Handles cleanup and state
updates when finishing the use of a GPU ring. It may also adjust the KFD
scheduler, using a mutex to manage shared data access.

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarSrinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Suggested-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 57bcfa89

drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c

+29 −0
Original line number Diff line number Diff line
@@ -1985,6 +1985,17 @@ void amdgpu_gfx_enforce_isolation_handler(struct work_struct *work) 
	mutex_unlock(&adev->enforce_isolation_mutex);

}



/**

 * amdgpu_gfx_enforce_isolation_wait_for_kfd - Manage KFD wait period for process isolation

 * @adev: amdgpu_device pointer

 * @idx: Index of the GPU partition

 *

 * When kernel submissions come in, the jobs are given a time slice and once

 * that time slice is up, if there are KFD user queues active, kernel

 * submissions are blocked until KFD has had its time slice. Once the KFD time

 * slice is up, KFD user queues are preempted and kernel submissions are

 * unblocked and allowed to run again.

 */

static void

amdgpu_gfx_enforce_isolation_wait_for_kfd(struct amdgpu_device *adev,

					  u32 idx)
@@ -2030,6 +2041,15 @@ amdgpu_gfx_enforce_isolation_wait_for_kfd(struct amdgpu_device *adev, 
		msleep(GFX_SLICE_PERIOD_MS);

}



/**

 * amdgpu_gfx_enforce_isolation_ring_begin_use - Begin use of a ring with enforced isolation

 * @ring: Pointer to the amdgpu_ring structure

 *

 * Ring begin_use helper implementation for gfx which serializes access to the

 * gfx IP between kernel submission IOCTLs and KFD user queues when isolation

 * enforcement is enabled. The kernel submission IOCTLs and KFD user queues

 * each get a time slice when both are active.

 */

void amdgpu_gfx_enforce_isolation_ring_begin_use(struct amdgpu_ring *ring)

{

	struct amdgpu_device *adev = ring->adev;
@@ -2057,6 +2077,15 @@ void amdgpu_gfx_enforce_isolation_ring_begin_use(struct amdgpu_ring *ring) 
	mutex_unlock(&adev->enforce_isolation_mutex);

}



/**

 * amdgpu_gfx_enforce_isolation_ring_end_use - End use of a ring with enforced isolation

 * @ring: Pointer to the amdgpu_ring structure

 *

 * Ring end_use helper implementation for gfx which serializes access to the

 * gfx IP between kernel submission IOCTLs and KFD user queues when isolation

 * enforcement is enabled. The kernel submission IOCTLs and KFD user queues

 * each get a time slice when both are active.

 */

void amdgpu_gfx_enforce_isolation_ring_end_use(struct amdgpu_ring *ring)

{

	struct amdgpu_device *adev = ring->adev;