Re: [PATCH 2/2] dma-buf/dma-fence: Order setting of the signaled-bit properly

[kernel test robot <lkp@intel.com>]

Hi Philipp,

kernel test robot noticed the following build errors:

[auto build test ERROR on 1ecab8b0bad393750c60cc3819ce9c256595463c]

url:    https://github.com/intel-lab-lkp/linux/commits/Philipp-Stanner/asm-generic-bitops-Add-set_bit_release/20261021-115512
base:   1ecab8b0bad393750c60cc3819ce9c256595463c
patch link:    https://lore.kernel.org/r/20261021095512.1345191-4-phasta%40kernel.org
patch subject: [PATCH 2/2] dma-buf/dma-fence: Order setting of the signaled-bit properly
config: sparc64-allmodconfig (https://download.01.org/0day-ci/archive/20261026/202610261518.t3m9Kwds-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261026/202610261518.t3m9Kwds-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202610261518.t3m9Kwds-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/dma-buf/dma-fence.c:393:2: error: call to undeclared function 'set_bit_release'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     393 |         set_bit_release(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags);
         |         ^
   1 error generated.


vim +/set_bit_release +393 drivers/dma-buf/dma-fence.c

   337	
   338	/**
   339	 * dma_fence_signal_timestamp_locked - signal completion of a fence
   340	 * @fence: the fence to signal
   341	 * @timestamp: fence signal timestamp in kernel's CLOCK_MONOTONIC time domain
   342	 *
   343	 * Signal completion for software callbacks on a fence, this will unblock
   344	 * dma_fence_wait() calls and run all the callbacks added with
   345	 * dma_fence_add_callback(). Can be called multiple times, but since a fence
   346	 * can only go from the unsignaled to the signaled state and not back, it will
   347	 * only be effective the first time. Set the timestamp provided as the fence
   348	 * signal timestamp.
   349	 *
   350	 * Unlike dma_fence_signal_timestamp(), this function must be called with
   351	 * &dma_fence.lock held.
   352	 */
   353	void dma_fence_signal_timestamp_locked(struct dma_fence *fence,
   354					      ktime_t timestamp)
   355	{
   356		const struct dma_fence_ops *ops;
   357		struct dma_fence_cb *cur, *tmp;
   358		struct list_head cb_list;
   359	
   360		dma_fence_assert_held(fence);
   361	
   362		if (unlikely(dma_fence_test_signaled_flag(fence)))
   363			return;
   364	
   365		trace_dma_fence_signaled(fence);
   366	
   367		/*
   368		 * When neither a release nor a wait operation is specified set the ops
   369		 * pointer to NULL to allow the fence structure to become independent
   370		 * from who originally issued it.
   371		 */
   372		ops = rcu_dereference_protected(fence->ops, true);
   373		if (!ops->release && !ops->wait)
   374			RCU_INIT_POINTER(fence->ops, NULL);
   375	
   376		/* Stash the cb_list before replacing it with the timestamp */
   377		list_replace(&fence->cb_list, &cb_list);
   378	
   379		fence->timestamp = timestamp;
   380		set_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags);
   381	
   382		list_for_each_entry_safe(cur, tmp, &cb_list, node) {
   383			INIT_LIST_HEAD(&cur->node);
   384			cur->func(fence, cur);
   385		}
   386	
   387		/*
   388		 * This orders the signaled-state with the test_bit_acquire() in
   389		 * dma_fence_test_signaled_flag(). This ensures that functions like
   390		 * dma_fence_is_signaled() can only ever return true once signaling is
   391		 * completed (i.e., after the callbacks above ran).
   392		 */
 > 393		set_bit_release(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags);
   394	}
   395	EXPORT_SYMBOL(dma_fence_signal_timestamp_locked);
   396	

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