[RFC PATCH 10/13] drm/admgpu: make device state machine work in stack like way

[Jiang Liu]

Make the device state machine work in stack like way to better support
suspend/resume by following changes:

1. amdgpu_driver_load_kms()
	amdgpu_device_init()
		amdgpu_device_ip_early_init()
			ip_blocks[i].early_init()
			ip_blocks[i].status.valid = true
		amdgpu_device_ip_init()
			amdgpu_ras_init()
			ip_blocks[i].sw_init()
			ip_blocks[i].status.sw = true
			ip_blocks[i].hw_init()
			ip_blocks[i].status.hw = true
		amdgpu_device_ip_late_init()
			ip_blocks[i].late_init()
			ip_blocks[i].status.late_initialized = true
			amdgpu_ras_late_init()
				ras_blocks[i].ras_late_init()
					amdgpu_ras_feature_enable_on_boot()

2. amdgpu_pmops_suspend()/amdgpu_pmops_freeze()/amdgpu_pmops_poweroff()
	amdgpu_device_suspend()
		amdgpu_ras_early_fini()
			ras_blocks[i].ras_early_fini()
				amdgpu_ras_feature_disable()
		amdgpu_ras_suspend()
			amdgpu_ras_disable_all_features()
+++		ip_blocks[i].early_fini()
+++		ip_blocks[i].status.late_initialized = false
		ip_blocks[i].suspend()

3. amdgpu_pmops_resume()/amdgpu_pmops_thaw()/amdgpu_pmops_restore()
	amdgpu_device_resume()
		amdgpu_device_ip_resume()
			ip_blocks[i].resume()
		amdgpu_device_ip_late_init()
			ip_blocks[i].late_init()
			ip_blocks[i].status.late_initialized = true
			amdgpu_ras_late_init()
				ras_blocks[i].ras_late_init()
					amdgpu_ras_feature_enable_on_boot()
		amdgpu_ras_resume()
			amdgpu_ras_enable_all_features()

4. amdgpu_driver_unload_kms()
	amdgpu_device_fini_hw()
		amdgpu_ras_early_fini()
			ras_blocks[i].ras_early_fini()
+++		ip_blocks[i].early_fini()
+++		ip_blocks[i].status.late_initialized = false
		ip_blocks[i].hw_fini()
		ip_blocks[i].status.hw = false

5. amdgpu_driver_release_kms()
	amdgpu_device_fini_sw()
		amdgpu_device_ip_fini()
			ip_blocks[i].sw_fini()
			ip_blocks[i].status.sw = false
---			ip_blocks[i].status.valid = false
+++			amdgpu_ras_fini()
			ip_blocks[i].late_fini()
+++			ip_blocks[i].status.valid = false
---			ip_blocks[i].status.late_initialized = false
---			amdgpu_ras_fini()

The main changes include:
1) invoke ip_blocks[i].early_fini in amdgpu_pmops_suspend().
   Currently there's only one ip block which provides `early_fini`
   callback. We have add a check of `in_s3` to keep current behavior in
   function amdgpu_dm_early_fini(). So there should be no functional
   changes.
2) set ip_blocks[i].status.late_initialized to false after calling
   callback `early_fini`. We have auditted all usages of the
   late_initialized flag and no functional changes found.
3) only set ip_blocks[i].status.valid = false after calling the
   `late_fini` callback.
4) call amdgpu_ras_fini() before invoking ip_blocks[i].late_fini.

There's one more task left to analyze GPU reset related state machine
transitions.

Signed-off-by: Jiang Liu <gerry at linux.alibaba.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c    | 22 +++++++++++++++++--
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |  3 +++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 36a33a391411..5c6b39e5cdaa 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3411,6 +3411,8 @@ static int amdgpu_device_ip_fini(struct amdgpu_device *adev)
 		adev->ip_blocks[i].status.sw = false;
 	}
 
+	amdgpu_ras_fini(adev);
+
 	for (i = adev->num_ip_blocks - 1; i >= 0; i--) {
 		if (!adev->ip_blocks[i].status.valid)
 			continue;
@@ -3419,8 +3421,6 @@ static int amdgpu_device_ip_fini(struct amdgpu_device *adev)
 		adev->ip_blocks[i].status.valid = false;
 	}
 
-	amdgpu_ras_fini(adev);
-
 	return 0;
 }
 
@@ -3478,6 +3478,24 @@ static int amdgpu_device_ip_suspend_phase1(struct amdgpu_device *adev)
 	if (amdgpu_dpm_set_df_cstate(adev, DF_CSTATE_DISALLOW))
 		dev_warn(adev->dev, "Failed to disallow df cstate");
 
+	for (i = adev->num_ip_blocks - 1; i >= 0; i--) {
+		if (!adev->ip_blocks[i].status.valid)
+			continue;
+		if (!adev->ip_blocks[i].status.late_initialized)
+			continue;
+
+		if (adev->ip_blocks[i].version->funcs->early_fini) {
+			r = adev->ip_blocks[i].version->funcs->early_fini(&adev->ip_blocks[i]);
+			if (r) {
+				DRM_ERROR(" of IP block <%s> failed %d\n",
+					  adev->ip_blocks[i].version->funcs->name, r);
+				return r;
+			}
+		}
+
+		adev->ip_blocks[i].status.late_initialized = false;
+	}
+
 	for (i = adev->num_ip_blocks - 1; i >= 0; i--) {
 		if (!adev->ip_blocks[i].status.valid)
 			continue;
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index f622eb1551df..33a1a795c761 100755
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2175,6 +2175,9 @@ static int amdgpu_dm_early_fini(struct amdgpu_ip_block *ip_block)
 {
 	struct amdgpu_device *adev = ip_block->adev;
 
+	if (adev->in_s0ix || adev->in_s3 || adev->in_s4 || adev->in_suspend)
+		return 0;
+
 	amdgpu_dm_audio_fini(adev);
 
 	return 0;
-- 
2.43.5