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

[Christian König]

Am 13.09.21 um 10:09 schrieb xinhui pan:
Allow TTM know if vendor set new ttm mananger out of bounds by adding
build_bug_on.
Signed-off-by: xinhui pan <xinhui....@amd.com>

Yeah, that looks better. Reviewed-by: Christian König 
<christian.koe...@amd.com>

Going to push that to drm-misc-next.

Thanks,
Christian.

---
  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