[PATCH 1/2] drm/amdgpu: Add debug bit for userptr usage

[Shane Xiao]

In VM debug mode, it is desirable to notify the application
to correct the freeing sequence by unmapping the memory before
destroying the userptr in the old userptr path. Add a bitmask
to decide whether to send gpu vm fault to the applition.

Signed-off-by: Shane Xiao <shane.xiao at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h     | 1 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index cc26cf1bd843..6a4c75124ad3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1230,6 +1230,7 @@ struct amdgpu_device {
 	bool                            debug_enable_ras_aca;
 	bool                            debug_exp_resets;
 	bool                            debug_disable_gpu_ring_reset;
+	bool                            debug_vm_userptr;
 
 	/* Protection for the following isolation structure */
 	struct mutex                    enforce_isolation_mutex;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index b9a1ef343c79..0ea3693a94de 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -143,6 +143,7 @@ enum AMDGPU_DEBUG_MASK {
 	AMDGPU_DEBUG_ENABLE_EXP_RESETS = BIT(5),
 	AMDGPU_DEBUG_DISABLE_GPU_RING_RESET = BIT(6),
 	AMDGPU_DEBUG_SMU_POOL = BIT(7),
+	AMDGPU_DEBUG_VM_USERPTR = BIT(8),
 };
 
 unsigned int amdgpu_vram_limit = UINT_MAX;
@@ -2272,6 +2273,10 @@ static void amdgpu_init_debug_options(struct amdgpu_device *adev)
 		pr_info("debug: use vram for smu pool\n");
 		adev->pm.smu_debug_mask |= SMU_DEBUG_POOL_USE_VRAM;
 	}
+	if (amdgpu_debug_mask & AMDGPU_DEBUG_VM_USERPTR) {
+		pr_info("debug: VM mode debug for userptr is enabled\n");
+		adev->debug_vm_userptr = true;
+	}
 }
 
 static unsigned long amdgpu_fix_asic_type(struct pci_dev *pdev, unsigned long flags)
-- 
2.25.1