[PATCH v2 3/6] drm/amdxcp: introduce new API amdgpu_xcp_drm_dev_free()

[Jiang Liu]

Introduce new interface amdgpu_xcp_drm_dev_free() to free a specific
drm_device crreated by amdgpu_xcp_drm_dev_alloc(), which will be used
to do error recovery.

Signed-off-by: Jiang Liu <gerry at linux.alibaba.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_xcp.c     | 11 +++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_xcp.h     |  1 +
 drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.c | 70 +++++++++++++++++----
 drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.h |  1 +
 4 files changed, 70 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_xcp.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_xcp.c
index e209b5e101df..401fbaa0b6b8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_xcp.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_xcp.c
@@ -359,6 +359,8 @@ int amdgpu_xcp_dev_register(struct amdgpu_device *adev,
 		ret = drm_dev_register(adev->xcp_mgr->xcp[i].ddev, ent->driver_data);
 		if (ret)
 			return ret;
+
+		adev->xcp_mgr->xcp[i].registered = true;
 	}
 
 	return 0;
@@ -376,12 +378,19 @@ void amdgpu_xcp_dev_unplug(struct amdgpu_device *adev)
 		if (!adev->xcp_mgr->xcp[i].ddev)
 			break;
 
+		// Restore and free the original drm_device.
 		p_ddev = adev->xcp_mgr->xcp[i].ddev;
-		drm_dev_unplug(p_ddev);
+		if (adev->xcp_mgr->xcp[i].registered) {
+			drm_dev_unplug(p_ddev);
+			adev->xcp_mgr->xcp[i].registered = false;
+		}
 		p_ddev->render->dev = adev->xcp_mgr->xcp[i].rdev;
 		p_ddev->primary->dev = adev->xcp_mgr->xcp[i].pdev;
 		p_ddev->driver =  adev->xcp_mgr->xcp[i].driver;
 		p_ddev->vma_offset_manager = adev->xcp_mgr->xcp[i].vma_offset_manager;
+		amdgpu_xcp_drm_dev_free(p_ddev);
+
+		adev->xcp_mgr->xcp[i].ddev = NULL;
 	}
 }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_xcp.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_xcp.h
index b63f53242c57..cd06a4a232be 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_xcp.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_xcp.h
@@ -101,6 +101,7 @@ struct amdgpu_xcp {
 	uint8_t id;
 	uint8_t mem_id;
 	bool valid;
+	bool registered;
 	atomic_t	ref_cnt;
 	struct drm_device *ddev;
 	struct drm_device *rdev;
diff --git a/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.c b/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.c
index faed84172dd4..9058d71b4756 100644
--- a/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.c
+++ b/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.c
@@ -45,18 +45,26 @@ static const struct drm_driver amdgpu_xcp_driver = {
 
 static int8_t pdev_num;
 static struct xcp_device *xcp_dev[MAX_XCP_PLATFORM_DEVICE];
+static struct mutex xcp_mutex;
 
 int amdgpu_xcp_drm_dev_alloc(struct drm_device **ddev)
 {
 	struct platform_device *pdev;
 	struct xcp_device *pxcp_dev;
 	char dev_name[20];
-	int ret;
+	int ret, index;
 
+	mutex_lock(&xcp_mutex);
+	ret = -ENODEV;
 	if (pdev_num >= MAX_XCP_PLATFORM_DEVICE)
-		return -ENODEV;
+		goto out_unlock;
 
-	snprintf(dev_name, sizeof(dev_name), "amdgpu_xcp_%d", pdev_num);
+	for (index = 0; index < MAX_XCP_PLATFORM_DEVICE; index++) {
+		if (!xcp_dev[index])
+			break;
+	}
+
+	snprintf(dev_name, sizeof(dev_name), "amdgpu_xcp_%d", index);
 	pdev = platform_device_register_simple(dev_name, -1, NULL, 0);
 	if (IS_ERR(pdev))
 		return PTR_ERR(pdev);
@@ -72,10 +80,11 @@ int amdgpu_xcp_drm_dev_alloc(struct drm_device **ddev)
 		goto out_devres;
 	}
 
-	xcp_dev[pdev_num] = pxcp_dev;
-	xcp_dev[pdev_num]->pdev = pdev;
+	xcp_dev[index] = pxcp_dev;
+	xcp_dev[index]->pdev = pdev;
 	*ddev = &pxcp_dev->drm;
 	pdev_num++;
+	mutex_unlock(&xcp_mutex);
 
 	return 0;
 
@@ -83,21 +92,58 @@ int amdgpu_xcp_drm_dev_alloc(struct drm_device **ddev)
 	devres_release_group(&pdev->dev, NULL);
 out_unregister:
 	platform_device_unregister(pdev);
+out_unlock:
+	mutex_unlock(&xcp_mutex);
 
 	return ret;
 }
 EXPORT_SYMBOL(amdgpu_xcp_drm_dev_alloc);
 
-void amdgpu_xcp_drv_release(void)
+static void amdgpu_xcp_drm_dev_destroy(int index)
+{
+	struct platform_device *pdev;
+
+	pdev = xcp_dev[index]->pdev;
+	devres_release_group(&pdev->dev, NULL);
+	platform_device_unregister(pdev);
+	xcp_dev[index] = NULL;
+	pdev_num--;
+}
+
+void amdgpu_xcp_drm_dev_free(struct drm_device *ddev)
 {
-	for (--pdev_num; pdev_num >= 0; --pdev_num) {
-		struct platform_device *pdev = xcp_dev[pdev_num]->pdev;
+	int index;
+	struct xcp_device *pxcp_dev;
+
+	if (ddev == NULL)
+		return;
 
-		devres_release_group(&pdev->dev, NULL);
-		platform_device_unregister(pdev);
-		xcp_dev[pdev_num] = NULL;
+	pxcp_dev = container_of(ddev, struct xcp_device, drm);
+
+	mutex_lock(&xcp_mutex);
+	for (index = 0; index < MAX_XCP_PLATFORM_DEVICE; index++) {
+		if (xcp_dev[index] == pxcp_dev) {
+			amdgpu_xcp_drm_dev_destroy(index);
+			break;
+		}
+	}
+	mutex_unlock(&xcp_mutex);
+}
+EXPORT_SYMBOL(amdgpu_xcp_drm_dev_free);
+
+void amdgpu_xcp_drv_release(void)
+{
+	int index;
+
+	mutex_lock(&xcp_mutex);
+	for (index = 0; index < MAX_XCP_PLATFORM_DEVICE; index++) {
+		if (xcp_dev[index]) {
+			WARN_ON(xcp_dev[index]);
+			amdgpu_xcp_drm_dev_destroy(index);
+		}
 	}
-	pdev_num = 0;
+	WARN_ON(pdev_num != 0);
+	mutex_unlock(&xcp_mutex);
 }
 EXPORT_SYMBOL(amdgpu_xcp_drv_release);
 
diff --git a/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.h b/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.h
index c1c4b679bf95..580a1602c8e3 100644
--- a/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.h
+++ b/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.h
@@ -25,5 +25,6 @@
 #define _AMDGPU_XCP_DRV_H_
 
 int amdgpu_xcp_drm_dev_alloc(struct drm_device **ddev);
+void amdgpu_xcp_drm_dev_free(struct drm_device *ddev);
 void amdgpu_xcp_drv_release(void);
 #endif /* _AMDGPU_XCP_DRV_H_ */
-- 
2.43.5