[PATCH v2 3/4] drm/amdgpu: Fix amdgpu_device_reset_sriov retry logic

[Yunxiang Li]

The retry loop for SRIOV reset have refcount and memory leak issue.
Depending on which function call fails it can potentially call
amdgpu_amdkfd_pre/post_reset different number of times and causes
kfd_locked count to be wrong. This will block all future attempts at
opening /dev/kfd. The retry loop also leakes resources by calling
amdgpu_virt_init_data_exchange multiple times without calling the
corresponding fini function.

Align with the bare-metal reset path which doesn't have these issues.
This means taking the amdgpu_amdkfd_pre/post_reset functions out of the
reset loop and calling amdgpu_device_pre_asic_reset each retry which
properly free the resources from previous try by calling
amdgpu_virt_fini_data_exchange.

Signed-off-by: Yunxiang Li <Yunxiang.Li at amd.com>
---
v2: put back release full access and the missed return

 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 47 ++++++++++------------
 1 file changed, 22 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 33c889c027a5..b23645f23a2e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -5065,10 +5065,6 @@ static int amdgpu_device_reset_sriov(struct amdgpu_device *adev,
 {
 	int r;
 	struct amdgpu_hive_info *hive = NULL;
-	int retry_limit = 0;
-
-retry:
-	amdgpu_amdkfd_pre_reset(adev);
 
 	if (test_bit(AMDGPU_HOST_FLR, &reset_context->flags)) {
 		clear_bit(AMDGPU_HOST_FLR, &reset_context->flags);
@@ -5088,7 +5084,7 @@ static int amdgpu_device_reset_sriov(struct amdgpu_device *adev,
 	/* Resume IP prior to SMC */
 	r = amdgpu_device_ip_reinit_early_sriov(adev);
 	if (r)
-		goto error;
+		return r;
 
 	amdgpu_virt_init_data_exchange(adev);
 
@@ -5099,38 +5095,35 @@ static int amdgpu_device_reset_sriov(struct amdgpu_device *adev,
 	/* now we are okay to resume SMC/CP/SDMA */
 	r = amdgpu_device_ip_reinit_late_sriov(adev);
 	if (r)
-		goto error;
+		return r;
 
 	hive = amdgpu_get_xgmi_hive(adev);
 	/* Update PSP FW topology after reset */
 	if (hive && adev->gmc.xgmi.num_physical_nodes > 1)
 		r = amdgpu_xgmi_update_topology(hive, adev);
-
 	if (hive)
 		amdgpu_put_xgmi_hive(hive);
+	if (r)
+		return r;
 
-	if (!r) {
-		r = amdgpu_ib_ring_tests(adev);
-
-		amdgpu_amdkfd_post_reset(adev);
-	}
+	r = amdgpu_ib_ring_tests(adev);
+	if (r)
+		return r;
 
-error:
-	if (!r && adev->virt.gim_feature & AMDGIM_FEATURE_GIM_FLR_VRAMLOST) {
+	if (adev->virt.gim_feature & AMDGIM_FEATURE_GIM_FLR_VRAMLOST) {
 		amdgpu_inc_vram_lost(adev);
 		r = amdgpu_device_recover_vram(adev);
 	}
-	amdgpu_virt_release_full_gpu(adev, true);
+	if (r)
+		return r;
 
-	if (AMDGPU_RETRY_SRIOV_RESET(r)) {
-		if (retry_limit < AMDGPU_MAX_RETRY_LIMIT) {
-			retry_limit++;
-			goto retry;
-		} else
-			DRM_ERROR("GPU reset retry is beyond the retry limit\n");
-	}
+	/* need to be called during full access so we can't do it later like
+	 * bare-metal does.
+	 */
+	amdgpu_amdkfd_post_reset(adev);
+	amdgpu_virt_release_full_gpu(adev, true);
 
-	return r;
+	return 0;
 }
 
 /**
@@ -5689,6 +5682,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
 	int i, r = 0;
 	bool need_emergency_restart = false;
 	bool audio_suspended = false;
+	int retry_limit = AMDGPU_MAX_RETRY_LIMIT;
 
 	/*
 	 * Special case: RAS triggered and full reset isn't supported
@@ -5770,8 +5764,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
 
 		cancel_delayed_work_sync(&tmp_adev->delayed_init_work);
 
-		if (!amdgpu_sriov_vf(tmp_adev))
-			amdgpu_amdkfd_pre_reset(tmp_adev);
+		amdgpu_amdkfd_pre_reset(tmp_adev);
 
 		/*
 		 * Mark these ASICs to be reseted as untracked first
@@ -5830,6 +5823,10 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
 	/* Host driver will handle XGMI hive reset for SRIOV */
 	if (amdgpu_sriov_vf(adev)) {
 		r = amdgpu_device_reset_sriov(adev, reset_context);
+		if (AMDGPU_RETRY_SRIOV_RESET(r) && (retry_limit--) > 0) {
+			amdgpu_virt_release_full_gpu(adev, true);
+			goto retry;
+		}
 		if (r)
 			adev->asic_reset_res = r;
 
-- 
2.34.1