[PATCH v3 3/4] drm/amdgpu: add debugfs support for VM pagetable per client

[Sunil Khatri]

Each drm node is associated with a unique client-id.
Create a directory for each drm-file in the dri root
directory. This directory is unique to hold information
related to a client id which is unique in the system
irrespective of how many drm devices are on the system.

Adding root page table base address of the VM under
the client-id node along with the process information
in debugfs.

Signed-off-by: Sunil Khatri <sunil.khatri at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c |  2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c  | 58 ++++++++++++++++++++++++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h  |  4 +-
 3 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index d2ce7d86dbc8..aa912168fd68 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -1395,7 +1395,7 @@ int amdgpu_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)
 	if (r)
 		goto error_pasid;
 
-	r = amdgpu_vm_init(adev, &fpriv->vm, fpriv->xcp_id);
+	r = amdgpu_vm_init(adev, &fpriv->vm, fpriv->xcp_id, file_priv);
 	if (r)
 		goto error_pasid;
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 3911c78f8282..3c309e4021bd 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2520,12 +2520,67 @@ void amdgpu_vm_set_task_info(struct amdgpu_vm *vm)
 	get_task_comm(vm->task_info->process_name, current->group_leader);
 }
 
+#if defined(CONFIG_DEBUG_FS)
+static int amdgpu_pt_info_read(struct seq_file *m, void *unused)
+{
+	struct drm_file *file;
+	struct amdgpu_fpriv *fpriv;
+	struct pid *pid;
+	struct task_struct *task;
+	struct amdgpu_bo *root_bo;
+	int r;
+
+	file = (struct drm_file *)m->private;
+	if (!file || !file->driver_priv)
+		return -EINVAL;
+
+	fpriv = file->driver_priv;
+	if (!fpriv || !fpriv->vm.root.bo)
+		return -ENODEV;
+
+	root_bo = amdgpu_bo_ref(fpriv->vm.root.bo);
+	r = amdgpu_bo_reserve(root_bo, true);
+	if (r) {
+		amdgpu_bo_unref(&root_bo);
+		return 0;
+	}
+
+	rcu_read_lock();
+	pid = rcu_dereference(file->pid);
+	task = pid_task(pid, PIDTYPE_TGID);
+
+	seq_printf(m, "pid: %d\n", task ? task->pid : 0);
+	seq_printf(m, "comm: %s\n", task ? task->comm : "Unset");
+	seq_printf(m, "pt_base: 0x%llx\n", amdgpu_bo_gpu_offset(fpriv->vm.root.bo));
+
+	rcu_read_unlock();
+	amdgpu_bo_unreserve(root_bo);
+	amdgpu_bo_unref(&root_bo);
+
+	return 0;
+}
+
+static int amdgpu_pt_info_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, amdgpu_pt_info_read, inode->i_private);
+}
+
+static const struct file_operations amdgpu_pt_info_fops = {
+	.owner = THIS_MODULE,
+	.open  = amdgpu_pt_info_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = single_release,
+};
+#endif
+
 /**
  * amdgpu_vm_init - initialize a vm instance
  *
  * @adev: amdgpu_device pointer
  * @vm: requested vm
  * @xcp_id: GPU partition selection id
+ * @file: drm_file
  *
  * Init @vm fields.
  *
@@ -2533,7 +2588,7 @@ void amdgpu_vm_set_task_info(struct amdgpu_vm *vm)
  * 0 for success, error for failure.
  */
 int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
-		   int32_t xcp_id)
+		   int32_t xcp_id, struct drm_file *file)
 {
 	struct amdgpu_bo *root_bo;
 	struct amdgpu_bo_vm *root;
@@ -2609,6 +2664,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 	if (r)
 		DRM_DEBUG("Failed to create task info for VM\n");
 
+	debugfs_create_file("pt_info", 0444, file->debugfs_client, file, &amdgpu_pt_info_fops);
 	amdgpu_bo_unreserve(vm->root.bo);
 	amdgpu_bo_unref(&root_bo);
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
index f3ad687125ad..555afaf867c4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
@@ -487,7 +487,9 @@ int amdgpu_vm_set_pasid(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 			u32 pasid);
 
 long amdgpu_vm_wait_idle(struct amdgpu_vm *vm, long timeout);
-int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm, int32_t xcp_id);
+int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm, int32_t xcp_id,
+		   struct drm_file *file);
+
 int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm);
 void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm);
 int amdgpu_vm_lock_pd(struct amdgpu_vm *vm, struct drm_exec *exec,
-- 
2.34.1