[PATCH v2 1/5] drm/amdgpu: add gpu_recovery_allowed flag to amdgpu_device

[Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>]

Add a per-device boolean to control whether GPU recovery is attempted
on a hang, independently of the global amdgpu.gpu_recovery module
parameter. It defaults to true and is exposed as a write to the
existing amdgpu_gpu_recover debugfs file, so a single device can have
auto-recovery disabled without affecting every other GPU in the
system.

amdgpu_device_should_recover_gpu() now takes this flag into account.

Assisted-by: Claude:Sonnet 5
Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h        |  7 +++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |  5 +++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c  | 21 +++++++++++++++++----
 3 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 7974f9b7944f..21b33dc34edf 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -957,6 +957,13 @@ struct amdgpu_device {
 
 	struct amdgpu_uma_carveout_info uma_info;
 
+	/* Whether this device is allowed to attempt GPU recovery on a hang.
+	 * Defaults to true; can be turned off per-device (e.g. via the
+	 * amdgpu_gpu_recover debugfs file) independently of the global
+	 * amdgpu.gpu_recovery module parameter.
+	 */
+	bool gpu_recovery_allowed;
+
 	/* KFD
 	 * Must be last --ends in a flexible-array member.
 	 */
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 964efec0d335..5578d5f64937 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -4034,6 +4034,8 @@ int amdgpu_device_init(struct amdgpu_device *adev,
 		}
 	}
 
+	adev->gpu_recovery_allowed = true;
+
 fence_driver_init:
 	/* Fence driver */
 	r = amdgpu_fence_driver_sw_init(adev);
@@ -4834,6 +4836,9 @@ bool amdgpu_device_should_recover_gpu(struct amdgpu_device *adev)
 	if (amdgpu_gpu_recovery == 0)
 		goto disabled;
 
+	if (!adev->gpu_recovery_allowed)
+		goto disabled;
+
 	/* Skip soft reset check in fatal error mode */
 	if (!amdgpu_ras_is_poison_mode_supported(adev))
 		return true;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
index 3043ad041bb4..707e69d8bb11 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
@@ -975,9 +975,13 @@ static int amdgpu_debugfs_fence_info_show(struct seq_file *m, void *unused)
 }
 
 /*
- * amdgpu_debugfs_gpu_recover - manually trigger a gpu reset & recover
+ * amdgpu_debugfs_gpu_recover - manually trigger a gpu reset & recover,
+ * and control whether this device is allowed to auto-recover from a hang.
  *
- * Manually trigger a gpu reset at the next fence wait.
+ * Read triggers a gpu reset at the next fence wait.
+ *
+ * Write 0/1 to disable/enable auto GPU recovery for this device
+ * (equivalent to amdgpu.gpu_recovery=0, but scoped to this device only).
  */
 static int gpu_recover_get(void *data, u64 *val)
 {
@@ -1001,8 +1005,17 @@ static int gpu_recover_get(void *data, u64 *val)
 	return 0;
 }
 
+static int gpu_recover_set(void *data, u64 val)
+{
+	struct amdgpu_device *adev = (struct amdgpu_device *)data;
+
+	adev->gpu_recovery_allowed = !!val;
+
+	return 0;
+}
+
 DEFINE_SHOW_ATTRIBUTE(amdgpu_debugfs_fence_info);
-DEFINE_DEBUGFS_ATTRIBUTE(amdgpu_debugfs_gpu_recover_fops, gpu_recover_get, NULL,
+DEFINE_DEBUGFS_ATTRIBUTE(amdgpu_debugfs_gpu_recover_fops, gpu_recover_get, gpu_recover_set,
 			 "%lld\n");
 
 static void amdgpu_debugfs_reset_work(struct work_struct *work)
@@ -1037,7 +1050,7 @@ void amdgpu_debugfs_fence_init(struct amdgpu_device *adev)
 	if (!amdgpu_sriov_vf(adev)) {
 
 		INIT_WORK(&adev->reset_work, amdgpu_debugfs_reset_work);
-		debugfs_create_file("amdgpu_gpu_recover", 0444, root, adev,
+		debugfs_create_file("amdgpu_gpu_recover", 0644, root, adev,
 				    &amdgpu_debugfs_gpu_recover_fops);
 	}
 #endif
-- 
2.43.0