[v5 1/5] drm/amdxcp: introduce new API amdgpu_xcp_drm_dev_free()

[Jiang Liu <gerry@linux.alibaba.com>]

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@linux.alibaba.com>
---
 drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.c | 63 +++++++++++++++++----
 drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.h |  1 +
 2 files changed, 54 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.c b/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.c
index faed84172dd4..2ff5377d54cd 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 DEFINE_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;
+
+	guard(mutex)(&xcp_mutex);
 
 	if (pdev_num >= MAX_XCP_PLATFORM_DEVICE)
 		return -ENODEV;
 
-	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);
@@ -72,8 +80,8 @@ 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++;
 
@@ -88,16 +96,51 @@ int amdgpu_xcp_drm_dev_alloc(struct drm_device **ddev)
 }
 EXPORT_SYMBOL(amdgpu_xcp_drm_dev_alloc);
 
+static void __amdgpu_xcp_drm_dev_free(int index)
+{
+	struct platform_device *pdev;
+
+	WARN_ON(!pdev_num);
+	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)
+{
+	struct xcp_device *pxcp_dev;
+	int index;
+
+	if (ddev == NULL)
+		return;
+
+	guard(mutex)(&xcp_mutex);
+	WARN_ON(!pdev_num);
+
+	pxcp_dev = container_of(ddev, struct xcp_device, drm);
+	for (index = 0; index < MAX_XCP_PLATFORM_DEVICE; index++) {
+		if (xcp_dev[index] == pxcp_dev) {
+			__amdgpu_xcp_drm_dev_free(index);
+			break;
+		}
+	}
+}
+EXPORT_SYMBOL(amdgpu_xcp_drm_dev_free);
+
 void amdgpu_xcp_drv_release(void)
 {
-	for (--pdev_num; pdev_num >= 0; --pdev_num) {
-		struct platform_device *pdev = xcp_dev[pdev_num]->pdev;
+	int index;
 
-		devres_release_group(&pdev->dev, NULL);
-		platform_device_unregister(pdev);
-		xcp_dev[pdev_num] = NULL;
+	guard(mutex)(&xcp_mutex);
+
+	for (index = 0; pdev_num && index < MAX_XCP_PLATFORM_DEVICE; index++) {
+		if (xcp_dev[index])
+			__amdgpu_xcp_drm_dev_free(index);
 	}
-	pdev_num = 0;
+
+	WARN_ON(pdev_num != 0);
 }
 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