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Claiming for various reasons the > standard way of doing that in Linux is using a const ops struct that > ends up in unmodifiable memory. Ah! I was already wondering why the extra indirection was used. I'm perfectly fine to keep it. It just looked a bit odd. Regards, Christian. > > /Thomas > > >> --- >>  drivers/gpu/drm/ttm/ttm_bo.c      | 12 ++---------- >>  drivers/gpu/drm/ttm/ttm_bo_util.c |  2 +- >>  include/drm/ttm/ttm_bo.h          | 34 ++++++++++++++--------------- >> ----- >>  3 files changed, 17 insertions(+), 31 deletions(-) >> >> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c >> b/drivers/gpu/drm/ttm/ttm_bo.c >> index 2b470c1746f60..1fb8c53da0362 100644 >> --- a/drivers/gpu/drm/ttm/ttm_bo.c >> +++ b/drivers/gpu/drm/ttm/ttm_bo.c >> @@ -545,10 +545,6 @@ static s64 ttm_bo_evict_cb(struct ttm_lru_walk >> *walk, struct ttm_buffer_object * >>   return lret; >>  } >>   >> -static const struct ttm_lru_walk_ops ttm_evict_walk_ops = { >> - .process_bo = ttm_bo_evict_cb, >> -}; >> - >>  static int ttm_bo_evict_alloc(struct ttm_device *bdev, >>         struct ttm_resource_manager *man, >>         const struct ttm_place *place, >> @@ -560,7 +556,7 @@ static int ttm_bo_evict_alloc(struct ttm_device >> *bdev, >>  { >>   struct ttm_bo_evict_walk evict_walk = { >>   .walk = { >> - .ops = &ttm_evict_walk_ops, >> + .process_bo = ttm_bo_evict_cb, >>   .arg = { >>   .ctx = ctx, >>   .ticket = ticket, >> @@ -1187,10 +1183,6 @@ ttm_bo_swapout_cb(struct ttm_lru_walk *walk, >> struct ttm_buffer_object *bo) >>   return ret; >>  } >>   >> -const struct ttm_lru_walk_ops ttm_swap_ops = { >> - .process_bo = ttm_bo_swapout_cb, >> -}; >> - >>  /** >>   * ttm_bo_swapout() - Swap out buffer objects on the LRU list to >> shmem. >>   * @bdev: The ttm device. >> @@ -1209,7 +1201,7 @@ s64 ttm_bo_swapout(struct ttm_device *bdev, >> struct ttm_operation_ctx *ctx, >>  { >>   struct ttm_bo_swapout_walk swapout_walk = { >>   .walk = { >> - .ops = &ttm_swap_ops, >> + .process_bo = ttm_bo_swapout_cb, >>   .arg = { >>   .ctx = ctx, >>   .trylock_only = true, >> diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c >> b/drivers/gpu/drm/ttm/ttm_bo_util.c >> index 7ed085adf1c9b..29f068944a972 100644 >> --- a/drivers/gpu/drm/ttm/ttm_bo_util.c >> +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c >> @@ -919,7 +919,7 @@ s64 ttm_lru_walk_for_evict(struct ttm_lru_walk >> *walk, struct ttm_device *bdev, >>   s64 lret; >>   >>   ttm_bo_lru_for_each_reserved_guarded(&cursor, man, &walk- >>> arg, bo) { >> - lret = walk->ops->process_bo(walk, bo); >> + lret = walk->process_bo(walk, bo); >>   if (lret == -EBUSY || lret == -EALREADY) >>   lret = 0; >>   progress = (lret < 0) ? lret : progress + lret; >> diff --git a/include/drm/ttm/ttm_bo.h b/include/drm/ttm/ttm_bo.h >> index 1eae9eea5ff32..0fcd5082a7080 100644 >> --- a/include/drm/ttm/ttm_bo.h >> +++ b/include/drm/ttm/ttm_bo.h >> @@ -189,24 +189,6 @@ struct ttm_operation_ctx { >>   uint64_t bytes_moved; >>  }; >>   >> -struct ttm_lru_walk; >> - >> -/** struct ttm_lru_walk_ops - Operations for a LRU walk. */ >> -struct ttm_lru_walk_ops { >> - /** >> - * process_bo - Process this bo. >> - * @walk: struct ttm_lru_walk describing the walk. >> - * @bo: A locked and referenced buffer object. >> - * >> - * Return: Negative error code on error, User-defined >> positive value >> - * (typically, but not always, size of the processed bo) on >> success. >> - * On success, the returned values are summed by the walk >> and the >> - * walk exits when its target is met. >> - * 0 also indicates success, -EBUSY means this bo was >> skipped. >> - */ >> - s64 (*process_bo)(struct ttm_lru_walk *walk, struct >> ttm_buffer_object *bo); >> -}; >> - >>  /** >>   * struct ttm_lru_walk_arg - Common part for the variants of BO LRU >> walk. >>   */ >> @@ -223,8 +205,20 @@ struct ttm_lru_walk_arg { >>   * struct ttm_lru_walk - Structure describing a LRU walk. >>   */ >>  struct ttm_lru_walk { >> - /** @ops: Pointer to the ops structure. */ >> - const struct ttm_lru_walk_ops *ops; >> + /** >> + * process_bo - Process this bo. >> + * @walk: struct ttm_lru_walk describing the walk. >> + * @bo: A locked and referenced buffer object. >> + * >> + * Return: Negative error code on error, User-defined >> positive value >> + * (typically, but not always, size of the processed bo) on >> success. >> + * On success, the returned values are summed by the walk >> and the >> + * walk exits when its target is met. >> + * 0 also indicates success, -EBUSY means this bo was >> skipped. >> + */ >> + s64 (*process_bo)(struct ttm_lru_walk *walk, >> +   struct ttm_buffer_object *bo); >> + >>   /** @arg: Common bo LRU walk arguments. */ >>   struct ttm_lru_walk_arg arg; >>  };