[RFC PATCH v2] drm/ttm: Try to check if new ttm man out of bounds during compile

[xinhui pan <xinhui.pan@xxxxxxx>]

Allow TTM know if vendor set new ttm mananger out of bounds by adding
build_bug_on.

Signed-off-by: xinhui pan <xinhui.pan@xxxxxxx>
---
 drivers/gpu/drm/ttm/ttm_range_manager.c |  8 ++++----
 include/drm/ttm/ttm_device.h            |  3 +++
 include/drm/ttm/ttm_range_manager.h     | 18 ++++++++++++++++--
 3 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_range_manager.c b/drivers/gpu/drm/ttm/ttm_range_manager.c
index 03395386e8a7..f2d702b66749 100644
--- a/drivers/gpu/drm/ttm/ttm_range_manager.c
+++ b/drivers/gpu/drm/ttm/ttm_range_manager.c
@@ -138,7 +138,7 @@ static const struct ttm_resource_manager_func ttm_range_manager_func = {
  * Initialise a generic range manager for the selected memory type.
  * The range manager is installed for this device in the type slot.
  */
-int ttm_range_man_init(struct ttm_device *bdev,
+int ttm_range_man_init_nocheck(struct ttm_device *bdev,
 		       unsigned type, bool use_tt,
 		       unsigned long p_size)
 {
@@ -163,7 +163,7 @@ int ttm_range_man_init(struct ttm_device *bdev,
 	ttm_resource_manager_set_used(man, true);
 	return 0;
 }
-EXPORT_SYMBOL(ttm_range_man_init);
+EXPORT_SYMBOL(ttm_range_man_init_nocheck);
 
 /**
  * ttm_range_man_fini
@@ -173,7 +173,7 @@ EXPORT_SYMBOL(ttm_range_man_init);
  *
  * Remove the generic range manager from a slot and tear it down.
  */
-int ttm_range_man_fini(struct ttm_device *bdev,
+int ttm_range_man_fini_nocheck(struct ttm_device *bdev,
 		       unsigned type)
 {
 	struct ttm_resource_manager *man = ttm_manager_type(bdev, type);
@@ -197,4 +197,4 @@ int ttm_range_man_fini(struct ttm_device *bdev,
 	kfree(rman);
 	return 0;
 }
-EXPORT_SYMBOL(ttm_range_man_fini);
+EXPORT_SYMBOL(ttm_range_man_fini_nocheck);
diff --git a/include/drm/ttm/ttm_device.h b/include/drm/ttm/ttm_device.h
index 07d722950d5b..6f23724f5a06 100644
--- a/include/drm/ttm/ttm_device.h
+++ b/include/drm/ttm/ttm_device.h
@@ -285,12 +285,15 @@ int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
 static inline struct ttm_resource_manager *
 ttm_manager_type(struct ttm_device *bdev, int mem_type)
 {
+	BUILD_BUG_ON(__builtin_constant_p(mem_type)
+		     && mem_type >= TTM_NUM_MEM_TYPES);
 	return bdev->man_drv[mem_type];
 }
 
 static inline void ttm_set_driver_manager(struct ttm_device *bdev, int type,
 					  struct ttm_resource_manager *manager)
 {
+	BUILD_BUG_ON(__builtin_constant_p(type) && type >= TTM_NUM_MEM_TYPES);
 	bdev->man_drv[type] = manager;
 }
 
diff --git a/include/drm/ttm/ttm_range_manager.h b/include/drm/ttm/ttm_range_manager.h
index 22b6fa42ac20..7963b957e9ef 100644
--- a/include/drm/ttm/ttm_range_manager.h
+++ b/include/drm/ttm/ttm_range_manager.h
@@ -4,6 +4,7 @@
 #define _TTM_RANGE_MANAGER_H_
 
 #include <drm/ttm/ttm_resource.h>
+#include <drm/ttm/ttm_device.h>
 #include <drm/drm_mm.h>
 
 /**
@@ -33,10 +34,23 @@ to_ttm_range_mgr_node(struct ttm_resource *res)
 	return container_of(res, struct ttm_range_mgr_node, base);
 }
 
-int ttm_range_man_init(struct ttm_device *bdev,
+int ttm_range_man_init_nocheck(struct ttm_device *bdev,
 		       unsigned type, bool use_tt,
 		       unsigned long p_size);
-int ttm_range_man_fini(struct ttm_device *bdev,
+int ttm_range_man_fini_nocheck(struct ttm_device *bdev,
 		       unsigned type);
+static __always_inline int ttm_range_man_init(struct ttm_device *bdev,
+		       unsigned int type, bool use_tt,
+		       unsigned long p_size)
+{
+	BUILD_BUG_ON(__builtin_constant_p(type) && type >= TTM_NUM_MEM_TYPES);
+	return ttm_range_man_init_nocheck(bdev, type, use_tt, p_size);
+}
 
+static __always_inline int ttm_range_man_fini(struct ttm_device *bdev,
+		       unsigned int type)
+{
+	BUILD_BUG_ON(__builtin_constant_p(type) && type >= TTM_NUM_MEM_TYPES);
+	return ttm_range_man_fini_nocheck(bdev, type);
+}
 #endif
-- 
2.25.1